switch on

what's problem os cancelled CI
2026-08-31 19:03:42 +00:00 · 2023-12-11 14:12:55 +00:00 · 2023-12-11 14:12:47 +00:00 · 2023-12-11 11:00:02 +00:00 · 2023-12-11 09:07:41 +00:00 · 2023-12-11 13:16:03 +08:00
1066 changed files with 21182 additions and 33863 deletions
--- a/.github/ISSUE_TEMPLATE/bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/bug_report.yml
@@ -7,16 +7,17 @@ body:
 - type: markdown
  attributes:
    value: |
-      Please provide a minimal code example that reproduces the bug if possible.
-      Reports with a reproducible example or detailed information will likely receive fixes faster.
+      - **Please provide a minimal code example that reproduces the Bug!** :bug:
+        Reports with a reproducible example and descriptive detailed information will likely receive fixes faster.

 - type: textarea
  id: description
  attributes:
    label: Description
    description: |
-      Describe the problem. Code example can be given here.
-    placeholder: Bug reports with reproducible code or detailed information will be fixed faster.
+      Use DETAILED DESCRIPTIVE information about the problem.
+      Here, you go into more details about your Bug report. This section can be a few paragraphs long.
+    placeholder: Bug reports with reproducible code and detailed information will be fixed faster.
  validations:
    required: true
    
@@ -24,9 +25,7 @@ body:
  id: nim-version
  attributes:
    label: Nim Version
-    description: |
-      Can be obtained from `nim -v` on the command line along with the OS/architecture.
-      For development versions, make sure to include the commit hash.
+    description: Copy and paste the output of `nim -v` on the command line. For development versions, make sure to include the commit hash.
  validations:
    required: true

@@ -35,7 +34,7 @@ body:
  attributes:
    label: Current Output
    description: Please copy and paste any relevant log output. This will be automatically formatted into code, so no need for backticks.
-    placeholder: Bug reports with reproducible code or detailed information will be fixed faster.
+    placeholder: Bug reports with reproducible code and detailed information will be fixed faster.
    render: text

 - type: textarea
@@ -43,14 +42,14 @@ body:
  attributes:
    label: Expected Output
    description: Please copy and paste any relevant log output. This will be automatically formatted into code, so no need for backticks.
-    placeholder: Bug reports with reproducible code or detailed information will be fixed faster.
+    placeholder: Bug reports with reproducible code and detailed information will be fixed faster.
    render: text

 - type: textarea
-  id: known-workarounds
+  id: possible-solution
  attributes:
-    label: Known Workarounds
-    description: Provide any known workarounds.
+    label: Possible Solution
+    description: Propose a possible solution.
  validations:
    required: false

@@ -65,9 +64,13 @@ body:
 - type: markdown
  attributes:
    value: |
-      - Please check whether the problem still exists in the devel branch, which can be installed via [choosenim](https://github.com/nim-lang/choosenim/), [nightlies](https://github.com/nim-lang/nightlies/), or by [creating a temporary build of the compiler](https://nim-lang.github.io/Nim/intern.html#debugging-the-compiler-building-an-instrumented-compiler).
+      - Thanks for your contributions!, your Bug report will receive feedback from the community soon...
+      - Please check whether the problem still exists in the devel branch, see [rebuilding the compiler](https://nim-lang.github.io/Nim/intern.html#rebuilding-the-compiler).
      - Consider writing a PR targetting devel branch after filing this, see [contributing](https://nim-lang.github.io/Nim/contributing.html).
-      - If it's a pre-existing compiler bug, see [debugging the compiler](https://nim-lang.github.io/Nim/intern.html#debugging-the-compiler) which should give more context on a compiler crash.
-      - If it's a regression, you can help us by identifying which version introduced the bug by [bisecting](https://nim-lang.github.io/Nim/intern.html#bisecting-for-regressions) or at least trying known past releases (e.g. `choosenim 2.0.0`).
-        The Nim repo also supports bisecting in issue comments by adding `!nim c`, `!nim js` etc. before a code block, see [nimrun-action](https://github.com/juancarlospaco/nimrun-action).
+      - If it's a pre-existing compiler bug, see [Debugging the compiler](https://nim-lang.github.io/Nim/intern.html#debugging-the-compiler)
+        which should give more context on a compiler crash.
+      - If it's a regression, you can help us by identifying which version introduced the bug,
+        see [Bisecting for regressions](https://nim-lang.github.io/Nim/intern.html#bisecting-for-regressions),
+        or at least try known past releases (e.g. `choosenim 2.0.0`). The Nim repo also supports online bisecting
+        via making a comment, which contains a code block starting by `!nim c`, `!nim js` etc. , see [nimrun-action](https://github.com/juancarlospaco/nimrun-action).
      - [Please, consider a Donation for the Nim project.](https://nim-lang.org/donate.html)
--- a/.github/workflows/ci_bench.yml
+++ b/.github/workflows/ci_bench.yml
@@ -0,0 +1,115 @@
+name: Benchmarks CI
+on:
+  pull_request:
+  push:
+    branches:
+      - 'devel'
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-20.04]
+        cpu: [amd64]
+    name: '${{ matrix.os }}'
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 60 # refs bug #18178
+    steps:
+      - name: 'Checkout'
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 2
+
+      - name: 'Install node.js 20.x'
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+
+      - name: 'Install dependencies (Linux amd64)'
+        if: runner.os == 'Linux' && matrix.cpu == 'amd64'
+        run: |
+          sudo apt-fast update -qq
+          DEBIAN_FRONTEND='noninteractive' \
+            sudo apt-fast install --no-install-recommends -yq \
+              libcurl4-openssl-dev libgc-dev libsdl1.2-dev libsfml-dev \
+              valgrind libc6-dbg libblas-dev xorg-dev
+
+      - name: 'Add build binaries to PATH'
+        shell: bash
+        run: echo "${{ github.workspace }}/bin" >> "${GITHUB_PATH}"
+
+      - name: 'Build csourcesAny'
+        shell: bash
+        run: . ci/funs.sh && nimBuildCsourcesIfNeeded CC=gcc ucpu='${{ matrix.cpu }}'
+
+      - name: 'Build koch'
+        shell: bash
+        run: nim c koch
+
+      - name: 'Build Nim'
+        shell: bash
+        run: ./koch boot -d:release -d:nimStrictMode --lib:lib
+
+      - name: 'Build Nimble'
+        shell: bash
+        run: ./koch nimble
+
+      - name: 'Action'
+        shell: bash
+        run: nim c -r -d:release ci/action.nim
+
+      - name: 'Checkout minimize'
+        uses: actions/checkout@v4
+        with:
+          repository: 'nim-lang/ci_bench'
+          path: minimize
+
+      - name: 'Run minimize benchmarks'
+        shell: bash
+        run: ./minimize/minimize ci-bench
+
+      - name: 'Restore minimize cached database'
+        uses: actions/cache/restore@v3
+        with:
+          path: minimize.csv
+          key: minimize-db-key
+
+      - name: 'Update minimize db'
+        shell: bash
+        run: ./minimize/minimize update-db
+
+      - name: 'Save minimize cached database'
+        if: |
+          github.event_name == 'push' && github.ref == 'refs/heads/devel' &&
+          matrix.target == 'linux'
+        uses: actions/cache/save@v3
+        with:
+          path: minimize.csv
+          key: minimize-db-key
+
+      - name: 'Generate minimize report'
+        shell: bash
+        run: ./minimize/minimize generate-report
+
+      - name: 'Archive minimize report'
+        uses: actions/upload-artifact@v3
+        with:
+          name: minimize-report
+          path: |
+            minimize/minimize.html
+            minimize/minimize.csv
+
+      # Requires additional permissions, see:
+      # https://github.com/nim-lang/Nim/actions/runs/4778177321/jobs/8494423792?pr=21566
+      # - name: 'Publish HTML report'
+      #   uses: rossjrw/pr-preview-action@v1
+      #   with:
+      #     source-dir: minimize
+      #     umbrella-dir: minimize
+      #   env:
+      #     GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract md summary
+        run: |
+          cat minimize/summary.md  >> $GITHUB_STEP_SUMMARY
--- a/.github/workflows/ci_docs.yml
+++ b/.github/workflows/ci_docs.yml
@@ -41,11 +41,11 @@ jobs:
        target: [linux, windows, osx]
        include:
          - target: linux
-            os: ubuntu-22.04
+            os: ubuntu-20.04
          - target: windows
            os: windows-2019
          - target: osx
-            os: macos-13
+            os: macos-11

    name: ${{ matrix.target }}
    runs-on: ${{ matrix.os }}
@@ -109,7 +109,7 @@ jobs:
        if: |
          github.event_name == 'push' && github.ref == 'refs/heads/devel' &&
          matrix.target == 'linux'
-        uses: crazy-max/ghaction-github-pages@v4
+        uses: crazy-max/ghaction-github-pages@v3
        with:
          build_dir: doc/html
        env:
--- a/.github/workflows/ci_packages.yml
+++ b/.github/workflows/ci_packages.yml
@@ -4,7 +4,6 @@ on:
  push:
    branches:
      - 'devel'
-      - 'version-2-2'
      - 'version-2-0'
      - 'version-1-6'
      - 'version-1-2'
@@ -18,7 +17,7 @@ jobs:
    strategy:
      fail-fast: false
      matrix:
-        os: [ubuntu-22.04, macos-13]
+        os: [ubuntu-20.04, macos-11]
        cpu: [amd64]
        batch: ["allowed_failures", "0_3", "1_3", "2_3"] # list of `index_num`
    name: '${{ matrix.os }} (batch: ${{ matrix.batch }})'
@@ -49,7 +48,6 @@ jobs:
      - name: 'Install dependencies (macOS)'
        if: runner.os == 'macOS'
        run: brew install boehmgc make sfml gtk+3
-        # XXX can't find boehm and gtk on macos 13
      - name: 'Install dependencies (Windows)'
        if: runner.os == 'Windows'
        shell: bash
--- a/.github/workflows/ci_publish.yml
+++ b/.github/workflows/ci_publish.yml
@@ -11,7 +11,7 @@ jobs:
    strategy:
      fail-fast: false
      matrix:
-        os: [ubuntu-22.04]
+        os: [ubuntu-20.04]
        cpu: [amd64]
    name: '${{ matrix.os }}'
    runs-on: ${{ matrix.os }}
@@ -21,10 +21,10 @@ jobs:
        with:
          fetch-depth: 2

-      - name: 'Install node.js'
+      - name: 'Install node.js 20.x'
        uses: actions/setup-node@v4
        with:
-          node-version: ''
+          node-version: '20.x'

      - name: 'Install dependencies (Linux amd64)'
        if: runner.os == 'Linux' && matrix.cpu == 'amd64'
@@ -34,6 +34,17 @@ jobs:
            sudo apt-fast install --no-install-recommends -yq \
              libcurl4-openssl-dev libgc-dev libsdl1.2-dev libsfml-dev \
              valgrind libc6-dbg libblas-dev xorg-dev
+      - name: 'Install dependencies (macOS)'
+        if: runner.os == 'macOS'
+        run: brew install boehmgc make sfml gtk+3
+      - name: 'Install dependencies (Windows)'
+        if: runner.os == 'Windows'
+        shell: bash
+        run: |
+          set -e
+          . ci/funs.sh
+          nimInternalInstallDepsWindows
+          echo_run echo "${{ github.workspace }}/dist/mingw64/bin" >> "${GITHUB_PATH}"

      - name: 'Add build binaries to PATH'
        shell: bash
@@ -60,7 +71,7 @@ jobs:
        run: nim c -r -d:release ci/action.nim

      - name: 'Comment'
-        uses: actions/github-script@v7
+        uses: actions/github-script@v6
        with:
          script: |
            const fs = require('fs');
--- a/.github/workflows/stale.yml
+++ b/.github/workflows/stale.yml
@@ -9,7 +9,7 @@ jobs:
  stale:
    runs-on: ubuntu-latest
    steps:
-      - uses: actions/stale@v9
+      - uses: actions/stale@v8
        with:
          days-before-pr-stale:    365
          days-before-pr-close:    30
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -20,7 +20,7 @@ jobs:
  strategy:
    matrix:
      Linux_amd64:
-        vmImage: 'ubuntu-24.04'
+        vmImage: 'ubuntu-20.04'
        CPU: amd64
      # regularly breaks, refs bug #17325
 #       Linux_i386:
@@ -29,23 +29,23 @@ jobs:
 #         vmImage: 'ubuntu-18.04'
 #         CPU: i386
      OSX_amd64:
-        vmImage: 'macOS-13'
+        vmImage: 'macOS-11'
        CPU: amd64
      OSX_amd64_cpp:
-        vmImage: 'macOS-13'
+        vmImage: 'macOS-11'
        CPU: amd64
        NIM_COMPILE_TO_CPP: true
      Windows_amd64_batch0_3:
-        vmImage: 'windows-2025'
+        vmImage: 'windows-2019'
        CPU: amd64
        # see also: `NIM_TEST_PACKAGES`
        NIM_TESTAMENT_BATCH: "0_3"
      Windows_amd64_batch1_3:
-        vmImage: 'windows-2025'
+        vmImage: 'windows-2019'
        CPU: amd64
        NIM_TESTAMENT_BATCH: "1_3"
      Windows_amd64_batch2_3:
-        vmImage: 'windows-2025'
+        vmImage: 'windows-2019'
        CPU: amd64
        NIM_TESTAMENT_BATCH: "2_3"

@@ -80,12 +80,10 @@ jobs:
    - bash: |
        set -e
        . ci/funs.sh
-        echo_run sudo add-apt-repository universe
-        echo_run sudo apt-get update -qq
+        echo_run sudo apt-fast update -qq
        DEBIAN_FRONTEND='noninteractive' \
-          echo_run sudo apt-get install --no-install-recommends -yq \
-            gcc-14 g++-14 libpcre3 liblapack-dev libpcre3 liblapack-dev libcurl4-openssl-dev libgc-dev libsdl1.2-dev libsfml-dev valgrind libc6-dbg
-        echo_run sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-14 60 --slave /usr/bin/g++ g++ /usr/bin/g++-14
+          echo_run sudo apt-fast install --no-install-recommends -yq \
+            libcurl4-openssl-dev libgc-dev libsdl1.2-dev libsfml-dev valgrind libc6-dbg
      displayName: 'Install dependencies (amd64 Linux)'
      condition: and(succeeded(), eq(variables['skipci'], 'false'), eq(variables['Agent.OS'], 'Linux'), eq(variables['CPU'], 'amd64'))

@@ -102,16 +100,15 @@ jobs:
        Pin-Priority: 1001
        EOF

-        # echo_run sudo apt-get update -qq
-        echo_run sudo apt-get update -qq || echo "failed, see bug #17343"
+        # echo_run sudo apt-fast update -qq
+        echo_run sudo apt-fast update -qq || echo "failed, see bug #17343"
        # `:i386` (e.g. in `libffi-dev:i386`) is needed otherwise you may get:
        # `could not load: libffi.so` during dynamic loading.
        DEBIAN_FRONTEND='noninteractive' \
-          echo_run sudo apt-get install --no-install-recommends --allow-downgrades -yq \
+          echo_run sudo apt-fast install --no-install-recommends --allow-downgrades -yq \
            g++-multilib gcc-multilib libcurl4-openssl-dev:i386 libgc-dev:i386 \
            libsdl1.2-dev:i386 libsfml-dev:i386 libglib2.0-dev:i386 libffi-dev:i386

-
        cat << EOF > bin/gcc
        #!/bin/bash

@@ -133,7 +130,6 @@ jobs:
    - bash: brew install boehmgc make sfml
      displayName: 'Install dependencies (OSX)'
      condition: and(succeeded(), eq(variables['skipci'], 'false'), eq(variables['Agent.OS'], 'Darwin'))
-      # XXX can't find boehm on macos 13

    - bash: |
        set -e
--- a/build_all.bat
+++ b/build_all.bat
@@ -24,6 +24,6 @@ if not exist %nim_csources% (
  cd ..
  copy /y bin\nim.exe  %nim_csources%
 )
-bin\nim.exe c --noNimblePath --skipUserCfg --skipParentCfg --hints:off koch
-koch boot -d:release --skipUserCfg --skipParentCfg --hints:off
-koch tools --skipUserCfg --skipParentCfg --hints:off
+ bin\nim.exe c --noNimblePath --skipUserCfg --skipParentCfg --hints:off koch
+ koch boot -d:release --skipUserCfg --skipParentCfg --hints:off
+ koch tools --skipUserCfg --skipParentCfg --hints:off
--- a/changelog.md
+++ b/changelog.md
@@ -1,83 +1,48 @@
-# v2.x.x - yyyy-mm-dd
+# v2.2.0 - yyyy-mm-dd


 ## Changes affecting backward compatibility

- `-d:nimPreviewFloatRoundtrip` becomes the default. `system.addFloat` and `system.$` now can produce string representations of
-floating point numbers that are minimal in size and possess round-trip and correct
-rounding guarantees (via the
-[Dragonbox](https://raw.githubusercontent.com/jk-jeon/dragonbox/master/other_files/Dragonbox.pdf) algorithm). Use `-d:nimLegacySprintf` to emulate old behaviors.
-
- The `default` parameter of `tables.getOrDefault` has been renamed to `def` to
-  avoid conflicts with `system.default`, so named argument usage for this
-  parameter like `getOrDefault(..., default = ...)` will have to be changed.
-
- With `-d:nimPreviewCheckedClose`, the `close` function in the `std/syncio` module now raises an IO exception in case of an error.
-
- Unknown warnings and hints now gives warnings `warnUnknownNotes` instead of
-errors.
-
- With `-d:nimPreviewAsmSemSymbol`, backticked symbols are type checked in the `asm/emit` statements.
-
- The bare `except:` now panics on `Defect`. Use `except Exception:` or `except Defect:` to catch `Defect`. `--legacy:noPanicOnExcept` is provided for a transition period.
+- `-d:nimStrictDelete` becomes the default. An index error is produced when the index passed to `system.delete` was out of bounds. Use `-d:nimAuditDelete` to mimic the old behavior for backwards compatibility.
+- The default user-agent in `std/httpclient` has been changed to `Nim-httpclient/<version>` instead of `Nim httpclient/<version>` which was incorrect according to the HTTP spec.
+- Methods now support implementations based on a VTable by using `--experimental:vtables`. Methods are then confined to be in the same module where their type has been defined.
+- With `-d:nimPreviewNonVarDestructor`, non-var destructors become the default.

 ## Standard library additions and changes

-[//]: # "Additions:"
-
- `setutils.symmetricDifference` along with its operator version
-  `` setutils.`-+-` `` and in-place version `setutils.toggle` have been added
-  to more efficiently calculate the symmetric difference of bitsets.
- `strutils.multiReplace` overload for character set replacements in a single pass.
-	Useful for string sanitation. Follows existing multiReplace semantics.
-
 [//]: # "Changes:"

- `std/math` The `^` symbol now supports floating-point as exponent in addition to the Natural type.
+- Changed `std/osfiles.copyFile` to allow to specify `bufferSize` instead of a hardcoded one.
+- Changed `std/osfiles.copyFile` to use `POSIX_FADV_SEQUENTIAL` hints for kernel-level aggressive sequential read-aheads.
+- `std/htmlparser` has been moved to a nimble package, use `nimble` or `atlas` to install it.
+
+[//]: # "Additions:"
+
+- Added `newStringUninit` to system, which creates a new string of length `len` like `newString` but with uninitialized content.
+- Added `setLenUninit` to system, which doesn't initalize
+slots when enlarging a sequence.
+- Added `hasDefaultValue` to `std/typetraits` to check if a type has a valid default value.
+- Added Viewport API for the JavaScript targets in the `dom` module.
+
+[//]: # "Deprecations:"
+
+- Deprecates `system.newSeqUninitialized`, which is replaced by `newSeqUninit`.
+
+[//]: # "Removals:"

- `system.substr` implementation now uses `copymem` (wrapped C `memcpy`) for copying data, if available at compilation.
- `system.newStringUninit` is now considered free of side-effects allowing it to be used with `--experimental:strictFuncs`.

 ## Language changes

- An experimental option `--experimental:typeBoundOps` has been added that
-  implements the RFC https://github.com/nim-lang/RFCs/issues/380.
-  This makes the behavior of interfaces like `hash`, `$`, `==` etc. more
-  reliable for nominal types across indirect/restricted imports.
-
-  ```nim
-  # objs.nim
-  import std/hashes
-
-  type
-    Obj* = object
-      x*, y*: int
-      z*: string # to be ignored for equality
-
-  proc `==`*(a, b: Obj): bool =
-    a.x == b.x and a.y == b.y
-
-  proc hash*(a: Obj): Hash =
-    $!(hash(a.x) &! hash(a.y))
-  ```
-
-  ```nim
-  # main.nim
-  {.experimental: "typeBoundOps".}
-  from objs import Obj # objs.hash, objs.`==` not imported
-  import std/tables
-
-  var t: Table[Obj, int]
-  t[Obj(x: 3, y: 4, z: "debug")] = 34
-  echo t[Obj(x: 3, y: 4, z: "ignored")] # 34
-  ```
-
-  See the [experimental manual](https://nim-lang.github.io/Nim/manual_experimental.html#typeminusbound-overloads)
-  for more information.
+- `noInit` can be used in types and fields to disable member initializers in the C++ backend. 
+- C++ custom constructors initializers see https://nim-lang.org/docs/manual_experimental.htm#constructor-initializer
+- `member` can be used to attach a procedure to a C++ type.
+- C++ `constructor` now reuses `result` instead creating `this`.

 ## Compiler changes

+- `--nimcache` using a relative path as the argument in a config file is now relative to the config file instead of the current directory.

 ## Tool changes

- Added `--stdinfile` flag to name of the file used when running program from stdin (defaults to `stdinfile.nim`)
+- koch now allows bootstrapping with `-d:nimHasLibFFI`, replacing the older option of building the compiler directly w/ the `libffi` nimble package in tow.
+
--- a/changelogs/changelog_0_18_1.md
+++ b/changelogs/changelog_0_18_1.md
@@ -53,7 +53,7 @@
  - [``joyent_http_parser``](https://github.com/nim-lang/joyent_http_parser)

 - Proc [toCountTable](https://nim-lang.org/docs/tables.html#toCountTable,openArray[A])
-  now produces a `CountTable` with values corresponding to the number of occurrences
+  now produces a `CountTable` with values correspoding to the number of occurrences
  of the key in the input. It used to produce a table with all values set to `1`.

  Counting occurrences in a sequence used to be:
@@ -339,7 +339,7 @@ for i in a..b:

 - Fixed "ReraiseError when using try/except within finally block"
  ([#5871](https://github.com/nim-lang/Nim/issues/5871))
- Fixed "Range type inference leads to counter-intuitive behaviour"
+- Fixed "Range type inference leads to counter-intuitive behvaiour"
  ([#5854](https://github.com/nim-lang/Nim/issues/5854))
 - Fixed "JSON % operator can fail in extern procs with dynamic types"
  ([#6385](https://github.com/nim-lang/Nim/issues/6385))
@@ -403,7 +403,7 @@ for i in a..b:
  ([#6589](https://github.com/nim-lang/Nim/issues/6589))
 - Fixed "Generated c code calls function twice"
  ([#6292](https://github.com/nim-lang/Nim/issues/6292))
- Fixed "Range type inference leads to counter-intuitive behaviour"
+- Fixed "Range type inference leads to counter-intuitive behvaiour"
  ([#5854](https://github.com/nim-lang/Nim/issues/5854))
 - Fixed "New backward indexing is too limited"
  ([#6631](https://github.com/nim-lang/Nim/issues/6631))
--- a/changelogs/changelog_1_0_0.md
+++ b/changelogs/changelog_1_0_0.md
@@ -22,7 +22,7 @@

 - We removed `unicode.Rune16` without any deprecation period as the name
  was wrong (see the [RFC](https://github.com/nim-lang/RFCs/issues/151) for details)
-  and we didn't find any usage of it in the wild. If you still need it, add this
+  and we didn't find any usages of it in the wild. If you still need it, add this
  piece of code to your project:
 ```nim
 type
--- a/changelogs/changelog_1_0_2.md
+++ b/changelogs/changelog_1_0_2.md
@@ -11,7 +11,7 @@
 * Fixed "Assertion error when running `nim check` on compiler/nim.nim" [#12281](https://github.com/nim-lang/Nim/issues/12281)
 * Fixed "Compiler crash with empty array and generic instantiation with int as parameter" [#12264](https://github.com/nim-lang/Nim/issues/12264)
 * Fixed "Regression in JS backend codegen "Error: request to generate code for .compileTime proc"" [#12240](https://github.com/nim-lang/Nim/issues/12240)
-* Fix how `relativePath` handles case sensitivity
+* Fix how `relativePath` handle case sensitiviy
 * Fixed "SIGSEGV in compiler when using generic types and seqs" [#12336](https://github.com/nim-lang/Nim/issues/12336)
 * Fixed "[1.0.0] weird interaction between `import os` and casting integer to char on macosx trigger bad codegen" [#12291](https://github.com/nim-lang/Nim/issues/12291)
 * VM: no special casing for big endian machines
@@ -43,7 +43,7 @@
 * threadpool: fix link in docs (#12258)
 * Fix spellings (#12277)
 * fix #12278, don't expose internal PCRE documentation
-* Fixed "Documentation of quitprocs is wrong" [#12279](https://github.com/nim-lang/Nim/issues/12279)
+* Fixed "Documentation of quitprocs is wrong" [#12279(https://github.com/nim-lang/Nim/issues/12279)
 * Fix typo in docs
 * Fix reference to parseSpec proc in readme
 * [doc/tut1] removed discard discussion in comments
--- a/changelogs/changelog_1_2_0.md
+++ b/changelogs/changelog_1_2_0.md
@@ -169,7 +169,7 @@ echo f
 - The Nim compiler now supports a new pragma called ``.localPassc`` to
  pass specific compiler options to the C(++) backend for the C(++) file
  that was produced from the current Nim module.
- The compiler now infers "sink parameters". To disable this for a specific routine,
+- The compiler now inferes "sink parameters". To disable this for a specific routine,
  annotate it with `.nosinks`. To disable it for a section of code, use
  `{.push sinkInference: off.}`...`{.pop.}`.
 - The compiler now supports a new switch `--panics:on` that turns runtime
@@ -261,7 +261,7 @@ echo f
  ([#12812](https://github.com/nim-lang/Nim/issues/12812))
 - Fixed "Produce static/const initializations for variables when possible"
  ([#12216](https://github.com/nim-lang/Nim/issues/12216))
- Fixed "Assigning discriminator field leads to internal assert with --gc:destructors"
+- Fixed "Assigning descriminator field leads to internal assert with --gc:destructors"
  ([#12821](https://github.com/nim-lang/Nim/issues/12821))
 - Fixed "nimsuggest `use` command does not return all instances of symbol"
  ([#12832](https://github.com/nim-lang/Nim/issues/12832))
--- a/changelogs/changelog_2_0_0.md
+++ b/changelogs/changelog_2_0_0.md
@@ -283,7 +283,7 @@ The definition of `"strictFuncs"` was changed.
 The old definition was roughly: "A store to a ref/ptr deref is forbidden unless it's coming from a `var T` parameter".
 The new definition is: "A store to a ref/ptr deref is forbidden."

-This new definition is much easier to understand, the price is some expressiveness. The following code used to be
+This new definition is much easier to understand, the price is some expressitivity. The following code used to be
 accepted:

 ```nim
--- a/changelogs/changelog_2_0_0_details.md
+++ b/changelogs/changelog_2_0_0_details.md
@@ -72,7 +72,7 @@
 - `shallowCopy` and `shallow` are removed for ARC/ORC. Use `move` when possible or combine assignment and
 `sink` for optimization purposes.

- The experimental `nimPreviewDotLikeOps` switch is going to be removed or deprecated because it didn't fulfill its promises.
+- The experimental `nimPreviewDotLikeOps` switch is going to be removed or deprecated because it didn't fullfill its promises.

 - The `{.this.}` pragma, deprecated since 0.19, has been removed.
 - `nil` literals can no longer be directly assigned to variables or fields of `distinct` pointer types. They must be converted instead.
--- a/changelogs/changelog_2_2_0.md
+++ b/changelogs/changelog_2_2_0.md
@@ -1,248 +1,12 @@
-# v2.2.0 - 2024-10-02
-
+# v2.2.0 - 2023-mm-dd

 ## Changes affecting backward compatibility

- `-d:nimStrictDelete` becomes the default. An index error is produced when the index passed to `system.delete` is out of bounds. Use `-d:nimAuditDelete` to mimic the old behavior for backward compatibility.
-
- The default user-agent in `std/httpclient` has been changed to `Nim-httpclient/<version>` instead of `Nim httpclient/<version>` which was incorrect according to the HTTP spec.
-
- Methods now support implementations based on a VTable by using `--experimental:vtables`. Methods are then confined to the same module where their type has been defined.
-
- With `-d:nimPreviewNonVarDestructor`, non-var destructors become the default.
-
- A bug where tuple unpacking assignment with a longer tuple on the RHS than the LHS was allowed has been fixed, i.e. code like:
-  ```nim
-  var a, b: int
-  (a, b) = (1, 2, 3, 4)
-  ```
-  will no longer compile.
-
- `internalNew` is removed from the `system` module, use `new` instead.
-
- `bindMethod` in `std/jsffi` is deprecated, don't use it with closures.
-
- The JS backend now supports lambda lifting for closures. Use `--legacy:jsNoLambdaLifting` to emulate old behaviors.
-
- The JS backend now supports closure iterators.
-
- `owner` in `std/macros` is deprecated.
-
- Ambiguous type symbols in generic procs and templates now generate symchoice nodes.
-  Previously; in templates they would error immediately at the template definition,
-  and in generic procs a type symbol would arbitrarily be captured, losing the
-  information of the other symbols. This means that generic code can now give
-  errors for ambiguous type symbols, and macros operating on generic proc AST
-  may encounter symchoice nodes instead of the arbitrarily resolved type symbol nodes.
-
- Partial generic instantiation of routines is no longer allowed. Previously
-  it compiled in niche situations due to bugs in the compiler.
-
-  ```nim
-  proc foo[T, U](x: T, y: U) = echo (x, y)
-  proc foo[T, U](x: var T, y: U) = echo "var ", (x, y)
-
-  proc bar[T]() =
-    foo[float](1, "abc")
-
-  bar[int]() # before: (1.0, "abc"), now: type mismatch, missing generic parameter
-  ```
-
- `const` values now open a new scope for each constant, meaning symbols
-  declared in them can no longer be used outside or in the value of
-  other constants.
-
-  ```nim
-  const foo = (var a = 1; a)
-  const bar = a # error
-  let baz = a # error
-  ```
-
- The following POSIX wrappers have had their types changed from signed to
-  unsigned types on OSX and FreeBSD/OpenBSD to correct codegen errors:
-  - `Gid` (was `int32`, is now `uint32`)
-  - `Uid` (was `int32`, is now `uint32`)
-  - `Dev` (was `int32`, is now `uint32` on FreeBSD)
-  - `Nlink` (was `int16`, is now `uint32` on OpenBSD and `uint16` on OSX/other BSD)
-  - `sin6_flowinfo` and `sin6_scope_id` fields of `Sockaddr_in6`
-    (were `int32`, are now `uint32`)
-  - `n_net` field of `Tnetent` (was `int32`, is now `uint32`)
-
- The `Atomic[T]` type on C++ now uses C11 primitives by default instead of
-  `std::atomic`. To use `std::atomic` instead, `-d:nimUseCppAtomics` can be defined.
-
-
-
-
-
-
 ## Standard library additions and changes

-[//]: # "Changes:"
-
- Changed `std/osfiles.copyFile` to allow specifying `bufferSize` instead of a hard-coded one.
- Changed `std/osfiles.copyFile` to use `POSIX_FADV_SEQUENTIAL` hints for kernel-level aggressive sequential read-aheads.
- `std/htmlparser` has been moved to a nimble package, use `nimble` or `atlas` to install it.
- Changed `std/os.copyDir` and `copyDirWithPermissions` to allow skipping special "file" objects like FIFOs, device files, etc on Unix by specifying a `skipSpecial` parameter.
-
-[//]: # "Additions:"
-
- Added `newStringUninit` to the `system` module, which creates a new string of length `len` like `newString` but with uninitialized content.
- Added `setLenUninit` to the `system` module, which doesn't initialize
-slots when enlarging a sequence.
- Added `hasDefaultValue` to `std/typetraits` to check if a type has a valid default value.
- Added `rangeBase` to `std/typetraits` to obtain the base type of a range type or
-  convert a value with a range type to its base type.
- Added Viewport API for the JavaScript targets in the `dom` module.
- Added `toSinglyLinkedRing` and `toDoublyLinkedRing` to `std/lists` to convert from `openArray`s.
- ORC: To be enabled via `nimOrcStats` there is a new API called `GC_orcStats` that can be used to query how many
-  objects the cyclic collector did free. If the number is zero that is a strong indicator that you can use `--mm:arc`
-  instead of `--mm:orc`.
- A `$` template is provided for `Path` in `std/paths`.
- `std/hashes.hash(x:string)` changed to produce a 64-bit string `Hash` (based
-on Google's Farm Hash) which is also often faster than the present one.  Define
-`nimStringHash2` to get the old values back.  `--jsbigint=off` mode always only
-produces the old values.  This may impact your automated tests if they depend
-on hash order in some obvious or indirect way.  Using `sorted` or `OrderedTable`
-is often an easy workaround.
-
-[//]: # "Deprecations:"
-
- Deprecates `system.newSeqUninitialized`, which is replaced by `newSeqUninit`.
-
-[//]: # "Removals:"
-
-
-
-
-
-
 ## Language changes

- `noInit` can be used in types and fields to disable member initializers in the C++ backend.
-
- C++ custom constructors initializers see https://nim-lang.org/docs/manual_experimental.html#constructor-initializer
-
- `member` can be used to attach a procedure to a C++ type.
-
- Inside a C++ constructor, `result` can be used to access the created object rather than `this`.
-
- Tuple unpacking changes:
-  - Tuple unpacking assignment now supports using underscores to discard values.
-    ```nim
-    var a, c: int
-    (a, _, c) = (1, 2, 3)
-    ```
-  - Tuple unpacking variable declarations now support type annotations, but
-    only for the entire tuple.
-    ```nim
-    let (a, b): (int, int) = (1, 2)
-    let (a, (b, c)): (byte, (float, cstring)) = (1, (2, "abc"))
-    ```
-
- The experimental option `--experimental:openSym` has been added to allow
-  captured symbols in generic routine and template bodies respectively to be
-  replaced by symbols injected locally by templates/macros at instantiation
-  time. `bind` may be used to keep the captured symbols over the injected ones
-  regardless of enabling the option, but other methods like renaming the
-  captured symbols should be used instead so that the code is not affected by
-  context changes.
-
-  Since this change may affect runtime behavior, the experimental switch
-  `openSym` needs to be enabled; and a warning is given in the case where an
-  injected symbol would replace a captured symbol not bound by `bind` and
-  the experimental switch isn't enabled.
-
-  ```nim
-  const value = "captured"
-  template foo(x: int, body: untyped): untyped =
-    let value {.inject.} = "injected"
-    body
-
-  proc old[T](): string =
-    foo(123):
-      return value # warning: a new `value` has been injected, use `bind` or turn on `experimental:openSym`
-  echo old[int]() # "captured"
-
-  template oldTempl(): string =
-    block:
-      foo(123):
-        value # warning: a new `value` has been injected, use `bind` or turn on `experimental:openSym`
-  echo oldTempl() # "captured"
-
-  {.experimental: "openSym".}
-
-  proc bar[T](): string =
-    foo(123):
-      return value
-  assert bar[int]() == "injected" # previously it would be "captured"
-
-  proc baz[T](): string =
-    bind value
-    foo(123):
-      return value
-  assert baz[int]() == "captured"
-
-  template barTempl(): string =
-    block:
-      foo(123):
-        value
-  assert barTempl() == "injected" # previously it would be "captured"
-
-  template bazTempl(): string =
-    bind value
-    block:
-      foo(123):
-        value
-  assert bazTempl() == "captured"
-  ```
-
-  This option also generates a new node kind `nnkOpenSym` which contains
-  exactly 1 `nnkSym` node. In the future this might be merged with a slightly
-  modified `nnkOpenSymChoice` node but macros that want to support the
-  experimental feature should still handle `nnkOpenSym`, as the node kind would
-  simply not be generated as opposed to being removed.
-
-  Another experimental switch `genericsOpenSym` exists that enables this behavior
-  at instantiation time, meaning templates etc can enable it specifically when
-  they are being called. However this does not generate `nnkOpenSym` nodes
-  (unless the other switch is enabled) and so doesn't reflect the regular
-  behavior of the switch.
-
-  ```nim
-  const value = "captured"
-  template foo(x: int, body: untyped): untyped =
-    let value {.inject.} = "injected"
-    {.push experimental: "genericsOpenSym".}
-    body
-    {.pop.}
-
-  proc bar[T](): string =
-    foo(123):
-      return value
-  echo bar[int]() # "injected"
-
-  template barTempl(): string =
-    block:
-      var res: string
-      foo(123):
-        res = value
-      res
-  assert barTempl() == "injected"
-  ```
-
-
-
-
-
 ## Compiler changes

- `--nimcache` using a relative path as the argument in a config file is now relative to the config file instead of the current directory.
-
-
-
-
-
 ## Tool changes

- koch now allows bootstrapping with `-d:nimHasLibFFI`, replacing the older option of building the compiler directly w/ the `libffi` nimble package.
--- a/changelogs/changelog_X_XX_X.md
+++ b/changelogs/changelog_X_XX_X.md
@@ -1,4 +1,4 @@
-# v2.xx.x - yyyy-mm-dd
+# v1.xx.x - yyyy-mm-dd

 This is an example file.
 The changes should go to changelog.md!
--- a/compiler/aliases.nim
+++ b/compiler/aliases.nim
@@ -51,16 +51,14 @@ proc isPartOfAux(a, b: PType, marker: var IntSet): TAnalysisResult =
  if compareTypes(a, b, dcEqIgnoreDistinct): return arYes
  case a.kind
  of tyObject:
-    if a.baseClass != nil:
-      result = isPartOfAux(a.baseClass.skipTypes(skipPtrs), b, marker)
+    if a[0] != nil:
+      result = isPartOfAux(a[0].skipTypes(skipPtrs), b, marker)
    if result == arNo: result = isPartOfAux(a.n, b, marker)
  of tyGenericInst, tyDistinct, tyAlias, tySink:
-    result = isPartOfAux(skipModifier(a), b, marker)
-  of tySet, tyArray:
-    result = isPartOfAux(a.elementType, b, marker)
-  of tyTuple:
-    for aa in a.kids:
-      result = isPartOfAux(aa, b, marker)
+    result = isPartOfAux(lastSon(a), b, marker)
+  of tyArray, tySet, tyTuple:
+    for i in 0..<a.len:
+      result = isPartOfAux(a[i], b, marker)
      if result == arYes: return
  else: discard

--- a/compiler/ast.nim
+++ b/compiler/ast.nim
--- a/compiler/astalgo.nim
+++ b/compiler/astalgo.nim
@@ -12,18 +12,24 @@
 # the data structures here are used in various places of the compiler.

 import
-  ast, astyaml, options, lineinfos, idents, rodutils,
+  ast, options, lineinfos, ropes, idents, rodutils,
  msgs

 import std/[hashes, intsets]
 import std/strutils except addf

-export astyaml.treeToYaml, astyaml.typeToYaml, astyaml.symToYaml, astyaml.lineInfoToStr
-
 when defined(nimPreviewSlimSystem):
  import std/assertions

 proc hashNode*(p: RootRef): Hash
+proc treeToYaml*(conf: ConfigRef; n: PNode, indent: int = 0, maxRecDepth: int = - 1): Rope
+  # Convert a tree into its YAML representation; this is used by the
+  # YAML code generator and it is invaluable for debugging purposes.
+  # If maxRecDepht <> -1 then it won't print the whole graph.
+proc typeToYaml*(conf: ConfigRef; n: PType, indent: int = 0, maxRecDepth: int = - 1): Rope
+proc symToYaml*(conf: ConfigRef; n: PSym, indent: int = 0, maxRecDepth: int = - 1): Rope
+proc lineInfoToStr*(conf: ConfigRef; info: TLineInfo): Rope
+

 # these are for debugging only: They are not really deprecated, but I want
 # the warning so that release versions do not contain debugging statements:
@@ -31,6 +37,15 @@ proc debug*(n: PSym; conf: ConfigRef = nil) {.exportc: "debugSym", deprecated.}
 proc debug*(n: PType; conf: ConfigRef = nil) {.exportc: "debugType", deprecated.}
 proc debug*(n: PNode; conf: ConfigRef = nil) {.exportc: "debugNode", deprecated.}

+proc typekinds*(t: PType) {.deprecated.} =
+  var t = t
+  var s = ""
+  while t != nil and t.len > 0:
+    s.add $t.kind
+    s.add " "
+    t = t.lastSon
+  echo s
+
 template debug*(x: PSym|PType|PNode) {.deprecated.} =
  when compiles(c.config):
    debug(c.config, x)
@@ -65,6 +80,16 @@ template mdbg*: bool {.deprecated.} =
  else:
    error()

+# --------------------------- ident tables ----------------------------------
+proc idTableGet*(t: TIdTable, key: PIdObj): RootRef
+proc idTableGet*(t: TIdTable, key: int): RootRef
+proc idTablePut*(t: var TIdTable, key: PIdObj, val: RootRef)
+proc idTableHasObjectAsKey*(t: TIdTable, key: PIdObj): bool
+  # checks if `t` contains the `key` (compared by the pointer value, not only
+  # `key`'s id)
+proc idNodeTableGet*(t: TIdNodeTable, key: PIdObj): PNode
+proc idNodeTablePut*(t: var TIdNodeTable, key: PIdObj, val: PNode)
+
 # ---------------------------------------------------------------------------

 proc lookupInRecord*(n: PNode, field: PIdent): PSym
@@ -220,6 +245,170 @@ proc mustRehash(length, counter: int): bool =
  assert(length > counter)
  result = (length * 2 < counter * 3) or (length - counter < 4)

+proc rspaces(x: int): Rope =
+  # returns x spaces
+  result = rope(spaces(x))
+
+proc toYamlChar(c: char): string =
+  case c
+  of '\0'..'\x1F', '\x7F'..'\xFF': result = "\\u" & strutils.toHex(ord(c), 4)
+  of '\'', '\"', '\\': result = '\\' & c
+  else: result = $c
+
+proc makeYamlString*(s: string): Rope =
+  # We have to split long strings into many ropes. Otherwise
+  # this could trigger InternalError(111). See the ropes module for
+  # further information.
+  const MaxLineLength = 64
+  result = ""
+  var res = "\""
+  for i in 0..<s.len:
+    if (i + 1) mod MaxLineLength == 0:
+      res.add('\"')
+      res.add("\n")
+      result.add(rope(res))
+      res = "\""              # reset
+    res.add(toYamlChar(s[i]))
+  res.add('\"')
+  result.add(rope(res))
+
+proc flagsToStr[T](flags: set[T]): Rope =
+  if flags == {}:
+    result = rope("[]")
+  else:
+    result = ""
+    for x in items(flags):
+      if result != "": result.add(", ")
+      result.add(makeYamlString($x))
+    result = "[" & result & "]"
+
+proc lineInfoToStr(conf: ConfigRef; info: TLineInfo): Rope =
+  result = "[$1, $2, $3]" % [makeYamlString(toFilename(conf, info)),
+                             rope(toLinenumber(info)),
+                             rope(toColumn(info))]
+
+proc treeToYamlAux(conf: ConfigRef; n: PNode, marker: var IntSet,
+                   indent, maxRecDepth: int): Rope
+proc symToYamlAux(conf: ConfigRef; n: PSym, marker: var IntSet,
+                  indent, maxRecDepth: int): Rope
+proc typeToYamlAux(conf: ConfigRef; n: PType, marker: var IntSet,
+                   indent, maxRecDepth: int): Rope
+
+proc symToYamlAux(conf: ConfigRef; n: PSym, marker: var IntSet, indent: int,
+                  maxRecDepth: int): Rope =
+  if n == nil:
+    result = rope("null")
+  elif containsOrIncl(marker, n.id):
+    result = "\"$1\"" % [rope(n.name.s)]
+  else:
+    var ast = treeToYamlAux(conf, n.ast, marker, indent + 2, maxRecDepth - 1)
+                                 #rope("typ"), typeToYamlAux(conf, n.typ, marker,
+                                 #  indent + 2, maxRecDepth - 1),
+    let istr = rspaces(indent + 2)
+    result = rope("{")
+    result.addf("$N$1\"kind\": $2", [istr, makeYamlString($n.kind)])
+    result.addf("$N$1\"name\": $2", [istr, makeYamlString(n.name.s)])
+    result.addf("$N$1\"typ\": $2", [istr, typeToYamlAux(conf, n.typ, marker, indent + 2, maxRecDepth - 1)])
+    if conf != nil:
+      # if we don't pass the config, we probably don't care about the line info
+      result.addf("$N$1\"info\": $2", [istr, lineInfoToStr(conf, n.info)])
+    if card(n.flags) > 0:
+      result.addf("$N$1\"flags\": $2", [istr, flagsToStr(n.flags)])
+    result.addf("$N$1\"magic\": $2", [istr, makeYamlString($n.magic)])
+    result.addf("$N$1\"ast\": $2", [istr, ast])
+    result.addf("$N$1\"options\": $2", [istr, flagsToStr(n.options)])
+    result.addf("$N$1\"position\": $2", [istr, rope(n.position)])
+    result.addf("$N$1\"k\": $2", [istr, makeYamlString($n.loc.k)])
+    result.addf("$N$1\"storage\": $2", [istr, makeYamlString($n.loc.storage)])
+    if card(n.loc.flags) > 0:
+      result.addf("$N$1\"flags\": $2", [istr, makeYamlString($n.loc.flags)])
+    result.addf("$N$1\"r\": $2", [istr, n.loc.r])
+    result.addf("$N$1\"lode\": $2", [istr, treeToYamlAux(conf, n.loc.lode, marker, indent + 2, maxRecDepth - 1)])
+    result.addf("$N$1}", [rspaces(indent)])
+
+proc typeToYamlAux(conf: ConfigRef; n: PType, marker: var IntSet, indent: int,
+                   maxRecDepth: int): Rope =
+  var sonsRope: Rope
+  if n == nil:
+    result = ""
+    sonsRope = rope("null")
+  elif containsOrIncl(marker, n.id):
+    result = ""
+    sonsRope = "\"$1 @$2\"" % [rope($n.kind), rope(
+        strutils.toHex(cast[int](n), sizeof(n) * 2))]
+  else:
+    if n.len > 0:
+      sonsRope = rope("[")
+      for i in 0..<n.len:
+        if i > 0: sonsRope.add(",")
+        sonsRope.addf("$N$1$2", [rspaces(indent + 4), typeToYamlAux(conf, n[i],
+            marker, indent + 4, maxRecDepth - 1)])
+      sonsRope.addf("$N$1]", [rspaces(indent + 2)])
+    else:
+      sonsRope = rope("null")
+
+    let istr = rspaces(indent + 2)
+    result = rope("{")
+    result.addf("$N$1\"kind\": $2", [istr, makeYamlString($n.kind)])
+    result.addf("$N$1\"sym\": $2",  [istr, symToYamlAux(conf, n.sym, marker, indent + 2, maxRecDepth - 1)])
+    result.addf("$N$1\"n\": $2",     [istr, treeToYamlAux(conf, n.n, marker, indent + 2, maxRecDepth - 1)])
+    if card(n.flags) > 0:
+      result.addf("$N$1\"flags\": $2", [istr, flagsToStr(n.flags)])
+    result.addf("$N$1\"callconv\": $2", [istr, makeYamlString($n.callConv)])
+    result.addf("$N$1\"size\": $2", [istr, rope(n.size)])
+    result.addf("$N$1\"align\": $2", [istr, rope(n.align)])
+    result.addf("$N$1\"sons\": $2", [istr, sonsRope])
+
+proc treeToYamlAux(conf: ConfigRef; n: PNode, marker: var IntSet, indent: int,
+                   maxRecDepth: int): Rope =
+  if n == nil:
+    result = rope("null")
+  else:
+    var istr = rspaces(indent + 2)
+    result = "{$N$1\"kind\": $2" % [istr, makeYamlString($n.kind)]
+    if maxRecDepth != 0:
+      if conf != nil:
+        result.addf(",$N$1\"info\": $2", [istr, lineInfoToStr(conf, n.info)])
+      case n.kind
+      of nkCharLit..nkUInt64Lit:
+        result.addf(",$N$1\"intVal\": $2", [istr, rope(n.intVal)])
+      of nkFloatLit, nkFloat32Lit, nkFloat64Lit:
+        result.addf(",$N$1\"floatVal\": $2",
+            [istr, rope(n.floatVal.toStrMaxPrecision)])
+      of nkStrLit..nkTripleStrLit:
+        result.addf(",$N$1\"strVal\": $2", [istr, makeYamlString(n.strVal)])
+      of nkSym:
+        result.addf(",$N$1\"sym\": $2",
+             [istr, symToYamlAux(conf, n.sym, marker, indent + 2, maxRecDepth)])
+      of nkIdent:
+        if n.ident != nil:
+          result.addf(",$N$1\"ident\": $2", [istr, makeYamlString(n.ident.s)])
+        else:
+          result.addf(",$N$1\"ident\": null", [istr])
+      else:
+        if n.len > 0:
+          result.addf(",$N$1\"sons\": [", [istr])
+          for i in 0..<n.len:
+            if i > 0: result.add(",")
+            result.addf("$N$1$2", [rspaces(indent + 4), treeToYamlAux(conf, n[i],
+                marker, indent + 4, maxRecDepth - 1)])
+          result.addf("$N$1]", [istr])
+      result.addf(",$N$1\"typ\": $2",
+           [istr, typeToYamlAux(conf, n.typ, marker, indent + 2, maxRecDepth)])
+    result.addf("$N$1}", [rspaces(indent)])
+
+proc treeToYaml(conf: ConfigRef; n: PNode, indent: int = 0, maxRecDepth: int = - 1): Rope =
+  var marker = initIntSet()
+  result = treeToYamlAux(conf, n, marker, indent, maxRecDepth)
+
+proc typeToYaml(conf: ConfigRef; n: PType, indent: int = 0, maxRecDepth: int = - 1): Rope =
+  var marker = initIntSet()
+  result = typeToYamlAux(conf, n, marker, indent, maxRecDepth)
+
+proc symToYaml(conf: ConfigRef; n: PSym, indent: int = 0, maxRecDepth: int = - 1): Rope =
+  var marker = initIntSet()
+  result = symToYamlAux(conf, n, marker, indent, maxRecDepth)
+
 import std/tables

 const backrefStyle = "\e[90m"
@@ -384,12 +573,14 @@ proc value(this: var DebugPrinter; value: PType) =
    this.key "n"
    this.value value.n

-  this.key "sons"
-  this.openBracket
-  for i, a in value.ikids:
-    if i > 0: this.comma
-    this.value a
-  this.closeBracket
+  if value.len > 0:
+    this.key "sons"
+    this.openBracket
+    for i in 0..<value.len:
+      this.value value[i]
+      if i != value.len - 1:
+        this.comma
+    this.closeBracket

  if value.n != nil:
    this.key "n"
@@ -458,33 +649,30 @@ proc value(this: var DebugPrinter; value: PNode) =


 proc debug(n: PSym; conf: ConfigRef) =
-  var this = DebugPrinter(
-    visited: initTable[pointer, int](),
-    renderSymType: true,
-    useColor: not defined(windows)
-  )
+  var this: DebugPrinter
+  this.visited = initTable[pointer, int]()
+  this.renderSymType = true
+  this.useColor = not defined(windows)
  this.value(n)
  echo($this.res)

 proc debug(n: PType; conf: ConfigRef) =
-  var this = DebugPrinter(
-    visited: initTable[pointer, int](),
-    renderSymType: true,
-    useColor: not defined(windows)
-  )
+  var this: DebugPrinter
+  this.visited = initTable[pointer, int]()
+  this.renderSymType = true
+  this.useColor = not defined(windows)
  this.value(n)
  echo($this.res)

 proc debug(n: PNode; conf: ConfigRef) =
-  var this = DebugPrinter(
-    visited: initTable[pointer, int](),
-    renderSymType: false,
-    useColor: not defined(windows)
-  )
+  var this: DebugPrinter
+  this.visited = initTable[pointer, int]()
+  #this.renderSymType = true
+  this.useColor = not defined(windows)
  this.value(n)
  echo($this.res)

-proc nextTry(h, maxHash: Hash): Hash {.inline.} =
+proc nextTry(h, maxHash: Hash): Hash =
  result = ((5 * h) + 1) and maxHash
  # For any initial h in range(maxHash), repeating that maxHash times
  # generates each int in range(maxHash) exactly once (see any text on
@@ -707,12 +895,125 @@ proc initTabIter*(ti: var TTabIter, tab: TStrTable): PSym =
    result = nextIter(ti, tab)

 iterator items*(tab: TStrTable): PSym =
-  var it: TTabIter = default(TTabIter)
+  var it: TTabIter
  var s = initTabIter(it, tab)
  while s != nil:
    yield s
    s = nextIter(it, tab)

+proc hasEmptySlot(data: TIdPairSeq): bool =
+  for h in 0..high(data):
+    if data[h].key == nil:
+      return true
+  result = false
+
+proc idTableRawGet(t: TIdTable, key: int): int =
+  var h: Hash
+  h = key and high(t.data)    # start with real hash value
+  while t.data[h].key != nil:
+    if t.data[h].key.id == key:
+      return h
+    h = nextTry(h, high(t.data))
+  result = - 1
+
+proc idTableHasObjectAsKey(t: TIdTable, key: PIdObj): bool =
+  var index = idTableRawGet(t, key.id)
+  if index >= 0: result = t.data[index].key == key
+  else: result = false
+
+proc idTableGet(t: TIdTable, key: PIdObj): RootRef =
+  var index = idTableRawGet(t, key.id)
+  if index >= 0: result = t.data[index].val
+  else: result = nil
+
+proc idTableGet(t: TIdTable, key: int): RootRef =
+  var index = idTableRawGet(t, key)
+  if index >= 0: result = t.data[index].val
+  else: result = nil
+
+iterator pairs*(t: TIdTable): tuple[key: int, value: RootRef] =
+  for i in 0..high(t.data):
+    if t.data[i].key != nil:
+      yield (t.data[i].key.id, t.data[i].val)
+
+proc idTableRawInsert(data: var TIdPairSeq, key: PIdObj, val: RootRef) =
+  var h: Hash
+  h = key.id and high(data)
+  while data[h].key != nil:
+    assert(data[h].key.id != key.id)
+    h = nextTry(h, high(data))
+  assert(data[h].key == nil)
+  data[h].key = key
+  data[h].val = val
+
+proc idTablePut(t: var TIdTable, key: PIdObj, val: RootRef) =
+  var
+    index: int
+    n: TIdPairSeq
+  index = idTableRawGet(t, key.id)
+  if index >= 0:
+    assert(t.data[index].key != nil)
+    t.data[index].val = val
+  else:
+    if mustRehash(t.data.len, t.counter):
+      newSeq(n, t.data.len * GrowthFactor)
+      for i in 0..high(t.data):
+        if t.data[i].key != nil:
+          idTableRawInsert(n, t.data[i].key, t.data[i].val)
+      assert(hasEmptySlot(n))
+      swap(t.data, n)
+    idTableRawInsert(t.data, key, val)
+    inc(t.counter)
+
+iterator idTablePairs*(t: TIdTable): tuple[key: PIdObj, val: RootRef] =
+  for i in 0..high(t.data):
+    if not isNil(t.data[i].key): yield (t.data[i].key, t.data[i].val)
+
+proc idNodeTableRawGet(t: TIdNodeTable, key: PIdObj): int =
+  var h: Hash
+  h = key.id and high(t.data) # start with real hash value
+  while t.data[h].key != nil:
+    if t.data[h].key.id == key.id:
+      return h
+    h = nextTry(h, high(t.data))
+  result = - 1
+
+proc idNodeTableGet(t: TIdNodeTable, key: PIdObj): PNode =
+  var index: int
+  index = idNodeTableRawGet(t, key)
+  if index >= 0: result = t.data[index].val
+  else: result = nil
+
+proc idNodeTableRawInsert(data: var TIdNodePairSeq, key: PIdObj, val: PNode) =
+  var h: Hash
+  h = key.id and high(data)
+  while data[h].key != nil:
+    assert(data[h].key.id != key.id)
+    h = nextTry(h, high(data))
+  assert(data[h].key == nil)
+  data[h].key = key
+  data[h].val = val
+
+proc idNodeTablePut(t: var TIdNodeTable, key: PIdObj, val: PNode) =
+  var index = idNodeTableRawGet(t, key)
+  if index >= 0:
+    assert(t.data[index].key != nil)
+    t.data[index].val = val
+  else:
+    if mustRehash(t.data.len, t.counter):
+      var n: TIdNodePairSeq
+      newSeq(n, t.data.len * GrowthFactor)
+      for i in 0..high(t.data):
+        if t.data[i].key != nil:
+          idNodeTableRawInsert(n, t.data[i].key, t.data[i].val)
+      swap(t.data, n)
+    idNodeTableRawInsert(t.data, key, val)
+    inc(t.counter)
+
+iterator pairs*(t: TIdNodeTable): tuple[key: PIdObj, val: PNode] =
+  for i in 0..high(t.data):
+    if not isNil(t.data[i].key): yield (t.data[i].key, t.data[i].val)
+
 proc initIITable(x: var TIITable) =
  x.counter = 0
  newSeq(x.data, StartSize)
@@ -758,6 +1059,14 @@ proc iiTablePut(t: var TIITable, key, val: int) =
    iiTableRawInsert(t.data, key, val)
    inc(t.counter)

+proc isAddrNode*(n: PNode): bool =
+  case n.kind
+    of nkAddr, nkHiddenAddr: true
+    of nkCallKinds:
+      if n[0].kind == nkSym and n[0].sym.magic == mAddr: true
+      else: false
+    else: false
+
 proc listSymbolNames*(symbols: openArray[PSym]): string =
  result = ""
  for sym in symbols:
--- a/compiler/astmsgs.nim
+++ b/compiler/astmsgs.nim
@@ -5,7 +5,7 @@ import options, ast, msgs
 proc typSym*(t: PType): PSym =
  result = t.sym
  if result == nil and t.kind == tyGenericInst: # this might need to be refined
-    result = t.genericHead.sym
+    result = t[0].sym

 proc addDeclaredLoc*(result: var string, conf: ConfigRef; sym: PSym) =
  result.add " [$1 declared in $2]" % [sym.kind.toHumanStr, toFileLineCol(conf, sym.info)]
@@ -24,12 +24,6 @@ proc addDeclaredLoc*(result: var string, conf: ConfigRef; typ: PType) =
    result.add " declared in " & toFileLineCol(conf, typ.sym.info)
  result.add "]"

-proc addTypeNodeDeclaredLoc*(result: var string, conf: ConfigRef; typ: PType) =
-  result.add " [$1" % typ.kind.toHumanStr
-  if typ.sym != nil:
-    result.add " declared in " & toFileLineCol(conf, typ.sym.info)
-  result.add "]"
-
 proc addDeclaredLocMaybe*(result: var string, conf: ConfigRef; typ: PType) =
  if optDeclaredLocs in conf.globalOptions: addDeclaredLoc(result, conf, typ)

--- a/compiler/astyaml.nim
+++ b/compiler/astyaml.nim
@@ -1,154 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2012 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-# AST YAML printing
-
-import "."/[ast, lineinfos, msgs, options, rodutils]
-import std/[intsets, strutils]
-
-proc addYamlString*(res: var string; s: string) =
-  res.add "\""
-  for c in s:
-    case c
-    of '\0' .. '\x1F', '\x7F' .. '\xFF':
-      res.add("\\u" & strutils.toHex(ord(c), 4))
-    of '\"', '\\':
-      res.add '\\' & c
-    else:
-      res.add c
-
-  res.add('\"')
-
-proc makeYamlString(s: string): string =
-  result = ""
-  result.addYamlString(s)
-
-proc flagsToStr[T](flags: set[T]): string =
-  if flags == {}:
-    result = "[]"
-  else:
-    result = ""
-    for x in items(flags):
-      if result != "":
-        result.add(", ")
-      result.addYamlString($x)
-    result = "[" & result & "]"
-
-proc lineInfoToStr*(conf: ConfigRef; info: TLineInfo): string =
-  result = "["
-  result.addYamlString(toFilename(conf, info))
-  result.addf ", $1, $2]", [toLinenumber(info), toColumn(info)]
-
-proc treeToYamlAux(res: var string; conf: ConfigRef; n: PNode; marker: var IntSet; indent, maxRecDepth: int)
-proc symToYamlAux(res: var string; conf: ConfigRef; n: PSym; marker: var IntSet; indent, maxRecDepth: int)
-proc typeToYamlAux(res: var string; conf: ConfigRef; n: PType; marker: var IntSet; indent, maxRecDepth: int)
-
-proc symToYamlAux(res: var string; conf: ConfigRef; n: PSym; marker: var IntSet; indent: int; maxRecDepth: int) =
-  if n == nil:
-    res.add("null")
-  elif containsOrIncl(marker, n.id):
-    res.addYamlString(n.name.s)
-  else:
-    let istr = spaces(indent * 4)
-
-    res.addf("kind: $1", [makeYamlString($n.kind)])
-    res.addf("\n$1name: $2", [istr, makeYamlString(n.name.s)])
-    res.addf("\n$1typ: ", [istr])
-    res.typeToYamlAux(conf, n.typ, marker, indent + 1, maxRecDepth - 1)
-    if conf != nil:
-      # if we don't pass the config, we probably don't care about the line info
-      res.addf("\n$1info: $2", [istr, lineInfoToStr(conf, n.info)])
-    if card(n.flags) > 0:
-      res.addf("\n$1flags: $2", [istr, flagsToStr(n.flags)])
-    res.addf("\n$1magic: $2", [istr, makeYamlString($n.magic)])
-    res.addf("\n$1ast: ", [istr])
-    res.treeToYamlAux(conf, n.ast, marker, indent + 1, maxRecDepth - 1)
-    res.addf("\n$1options: $2", [istr, flagsToStr(n.options)])
-    res.addf("\n$1position: $2", [istr, $n.position])
-    res.addf("\n$1k: $2", [istr, makeYamlString($n.loc.k)])
-    res.addf("\n$1storage: $2", [istr, makeYamlString($n.loc.storage)])
-    if card(n.loc.flags) > 0:
-      res.addf("\n$1flags: $2", [istr, makeYamlString($n.loc.flags)])
-    res.addf("\n$1snippet: $2", [istr, n.loc.snippet])
-    res.addf("\n$1lode: $2", [istr])
-    res.treeToYamlAux(conf, n.loc.lode, marker, indent + 1, maxRecDepth - 1)
-
-proc typeToYamlAux(res: var string; conf: ConfigRef; n: PType; marker: var IntSet; indent: int; maxRecDepth: int) =
-  if n == nil:
-    res.add("null")
-  elif containsOrIncl(marker, n.id):
-    res.addf "\"$1 @$2\"" % [$n.kind, strutils.toHex(cast[uint](n), sizeof(n) * 2)]
-  else:
-    let istr = spaces(indent * 4)
-    res.addf("kind: $2", [istr, makeYamlString($n.kind)])
-    res.addf("\n$1sym: ")
-    res.symToYamlAux(conf, n.sym, marker, indent + 1, maxRecDepth - 1)
-    res.addf("\n$1n: ")
-    res.treeToYamlAux(conf, n.n, marker, indent + 1, maxRecDepth - 1)
-    if card(n.flags) > 0:
-      res.addf("\n$1flags: $2", [istr, flagsToStr(n.flags)])
-    res.addf("\n$1callconv: $2", [istr, makeYamlString($n.callConv)])
-    res.addf("\n$1size: $2", [istr, $(n.size)])
-    res.addf("\n$1align: $2", [istr, $(n.align)])
-    if n.hasElementType:
-      res.addf("\n$1sons:")
-      for a in n.kids:
-        res.addf("\n  - ")
-        res.typeToYamlAux(conf, a, marker, indent + 1, maxRecDepth - 1)
-
-proc treeToYamlAux(res: var string; conf: ConfigRef; n: PNode; marker: var IntSet; indent: int;
-                   maxRecDepth: int) =
-  if n == nil:
-    res.add("null")
-  else:
-    var istr = spaces(indent * 4)
-    res.addf("kind: $1" % [makeYamlString($n.kind)])
-
-    if maxRecDepth != 0:
-      if conf != nil:
-        res.addf("\n$1info: $2", [istr, lineInfoToStr(conf, n.info)])
-      case n.kind
-      of nkCharLit .. nkInt64Lit:
-        res.addf("\n$1intVal: $2", [istr, $(n.intVal)])
-      of nkFloatLit, nkFloat32Lit, nkFloat64Lit:
-        res.addf("\n$1floatVal: $2", [istr, n.floatVal.toStrMaxPrecision])
-      of nkStrLit .. nkTripleStrLit:
-        res.addf("\n$1strVal: $2", [istr, makeYamlString(n.strVal)])
-      of nkSym:
-        res.addf("\n$1sym: ", [istr])
-        res.symToYamlAux(conf, n.sym, marker, indent + 1, maxRecDepth)
-      of nkIdent:
-        if n.ident != nil:
-          res.addf("\n$1ident: $2", [istr, makeYamlString(n.ident.s)])
-        else:
-          res.addf("\n$1ident: null", [istr])
-      else:
-        if n.len > 0:
-          res.addf("\n$1sons: ", [istr])
-          for i in 0 ..< n.len:
-            res.addf("\n$1  - ", [istr])
-            res.treeToYamlAux(conf, n[i], marker, indent + 1, maxRecDepth - 1)
-      if n.typ != nil:
-        res.addf("\n$1typ: ", [istr])
-        res.typeToYamlAux(conf, n.typ, marker, indent + 1, maxRecDepth)
-
-proc treeToYaml*(conf: ConfigRef; n: PNode; indent: int = 0; maxRecDepth: int = -1): string =
-  var marker = initIntSet()
-  result = newStringOfCap(1024)
-  result.treeToYamlAux(conf, n, marker, indent, maxRecDepth)
-
-proc typeToYaml*(conf: ConfigRef; n: PType; indent: int = 0; maxRecDepth: int = -1): string =
-  var marker = initIntSet()
-  result = newStringOfCap(1024)
-  result.typeToYamlAux(conf, n, marker, indent, maxRecDepth)
-
-proc symToYaml*(conf: ConfigRef; n: PSym; indent: int = 0; maxRecDepth: int = -1): string =
-  var marker = initIntSet()
-  result = newStringOfCap(1024)
-  result.symToYamlAux(conf, n, marker, indent, maxRecDepth)
--- a/compiler/backendpragmas.nim
+++ b/compiler/backendpragmas.nim
@@ -0,0 +1,25 @@
+import pragmas, options, ast, trees
+
+proc pushBackendOption(optionsStack: var seq[TOptions], options: var TOptions) =
+  optionsStack.add options
+
+proc popBackendOption(optionsStack: var seq[TOptions], options: var TOptions) =
+  options = optionsStack[^1]
+  optionsStack.setLen(optionsStack.len-1)
+
+proc processPushBackendOption*(optionsStack: var seq[TOptions], options: var TOptions,
+                           n: PNode, start: int) =
+  pushBackendOption(optionsStack, options)
+  for i in start..<n.len:
+    let it = n[i]
+    if it.kind in nkPragmaCallKinds and it.len == 2 and it[1].kind == nkIntLit:
+      let sw = whichPragma(it[0])
+      let opts = pragmaToOptions(sw)
+      if opts != {}:
+        if it[1].intVal != 0:
+          options.incl opts
+        else:
+          options.excl opts
+
+template processPopBackendOption*(optionsStack: var seq[TOptions], options: var TOptions) =
+  popBackendOption(optionsStack, options)
--- a/compiler/cbuilder.nim
+++ b/compiler/cbuilder.nim
@@ -1,121 +0,0 @@
-type
-  Snippet = string
-  Builder = string
-
-template newBuilder(s: string): Builder =
-  s
-
-proc addField(obj: var Builder; name, typ: Snippet) =
-  obj.add('\t')
-  obj.add(typ)
-  obj.add(" ")
-  obj.add(name)
-  obj.add(";\n")
-
-proc addField(obj: var Builder; field: PSym; name, typ: Snippet; isFlexArray: bool; initializer: Snippet) =
-  obj.add('\t')
-  if field.alignment > 0:
-    obj.add("NIM_ALIGN(")
-    obj.addInt(field.alignment)
-    obj.add(") ")
-  obj.add(typ)
-  if sfNoalias in field.flags:
-    obj.add(" NIM_NOALIAS")
-  obj.add(" ")
-  obj.add(name)
-  if isFlexArray:
-    obj.add("[SEQ_DECL_SIZE]")
-  if field.bitsize != 0:
-    obj.add(":")
-    obj.addInt(field.bitsize)
-  if initializer.len != 0:
-    obj.add(initializer)
-  obj.add(";\n")
-
-proc structOrUnion(t: PType): Snippet =
-  let t = t.skipTypes({tyAlias, tySink})
-  if tfUnion in t.flags: "union"
-  else: "struct"
-
-proc ptrType(t: Snippet): Snippet =
-  t & "*"
-
-template addStruct(obj: var Builder; m: BModule; typ: PType; name: string; baseType: string; body: typed) =
-  if tfPacked in typ.flags:
-    if hasAttribute in CC[m.config.cCompiler].props:
-      obj.add(structOrUnion(typ))
-      obj.add(" __attribute__((__packed__))")
-    else:
-      obj.add("#pragma pack(push, 1)\n")
-      obj.add(structOrUnion(typ))
-  else:
-    obj.add(structOrUnion(typ))
-  obj.add(" ")
-  obj.add(name)
-  type BaseClassKind = enum
-    bcNone, bcCppInherit, bcSupField, bcNoneRtti, bcNoneTinyRtti
-  var baseKind = bcNone
-  if typ.kind == tyObject:
-    if typ.baseClass == nil:
-      if lacksMTypeField(typ):
-        baseKind = bcNone
-      elif optTinyRtti in m.config.globalOptions:
-        baseKind = bcNoneTinyRtti
-      else:
-        baseKind = bcNoneRtti
-    elif m.compileToCpp:
-      baseKind = bcCppInherit
-    else:
-      baseKind = bcSupField
-  if baseKind == bcCppInherit:
-    obj.add(" : public ")
-    obj.add(baseType)
-  obj.add(" ")
-  obj.add("{\n")
-  let currLen = obj.len
-  case baseKind
-  of bcNone:
-    # rest of the options add a field or don't need it due to inheritance,
-    # we need to add the dummy field for uncheckedarray ahead of time
-    # so that it remains trailing
-    if typ.itemId notin m.g.graph.memberProcsPerType and
-        typ.n != nil and typ.n.len == 1 and typ.n[0].kind == nkSym and
-        typ.n[0].sym.typ.skipTypes(abstractInst).kind == tyUncheckedArray:
-      # only consists of flexible array field, add *initial* dummy field
-      obj.addField(name = "dummy", typ = "char")
-  of bcCppInherit: discard
-  of bcNoneRtti:
-    obj.addField(name = "m_type", typ = ptrType(cgsymValue(m, "TNimType")))
-  of bcNoneTinyRtti:
-    obj.addField(name = "m_type", typ = ptrType(cgsymValue(m, "TNimTypeV2")))
-  of bcSupField:
-    obj.addField(name = "Sup", typ = baseType)
-  body
-  if baseKind == bcNone and currLen == obj.len and typ.itemId notin m.g.graph.memberProcsPerType:
-    # no fields were added, add dummy field
-    obj.addField(name = "dummy", typ = "char")
-  obj.add("};\n")
-  if tfPacked in typ.flags and hasAttribute notin CC[m.config.cCompiler].props:
-    result.add("#pragma pack(pop)\n")
-
-template addFieldWithStructType(obj: var Builder; m: BModule; parentTyp: PType; fieldName: string, body: typed) =
-  ## adds a field with a `struct { ... }` type, building it according to `body`
-  obj.add('\t')
-  if tfPacked in parentTyp.flags:
-    if hasAttribute in CC[m.config.cCompiler].props:
-      obj.add("struct __attribute__((__packed__)) {\n")
-    else:
-      obj.add("#pragma pack(push, 1)\nstruct {")
-  else:
-    obj.add("struct {\n")
-  body
-  obj.add("} ")
-  obj.add(fieldName)
-  obj.add(";\n")
-  if tfPacked in parentTyp.flags and hasAttribute notin CC[m.config.cCompiler].props:
-    result.add("#pragma pack(pop)\n")
-
-template addAnonUnion(obj: var Builder; body: typed) =
-  obj.add "union{\n"
-  body
-  obj.add("};\n")
--- a/compiler/ccgcalls.nim
+++ b/compiler/ccgcalls.nim
@@ -76,23 +76,6 @@ proc isHarmlessStore(p: BProc; canRaise: bool; d: TLoc): bool =
  else:
    result = false

-proc cleanupTemp(p: BProc; returnType: PType, tmp: TLoc): bool =
-  if returnType.kind in {tyVar, tyLent}:
-    # we don't need to worry about var/lent return types
-    result = false
-  elif hasDestructor(returnType) and getAttachedOp(p.module.g.graph, returnType, attachedDestructor) != nil:
-    let dtor = getAttachedOp(p.module.g.graph, returnType, attachedDestructor)
-    var op = initLocExpr(p, newSymNode(dtor))
-    var callee = rdLoc(op)
-    let destroy = if dtor.typ.firstParamType.kind == tyVar:
-        callee & "(&" & rdLoc(tmp) & ")"
-      else:
-        callee & "(" & rdLoc(tmp) & ")"
-    raiseExitCleanup(p, destroy)
-    result = true
-  else:
-    result = false
-
 proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
               callee, params: Rope) =
  let canRaise = p.config.exc == excGoto and canRaiseDisp(p, ri[0])
@@ -100,17 +83,13 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
  var pl = callee & "(" & params
  # getUniqueType() is too expensive here:
  var typ = skipTypes(ri[0].typ, abstractInst)
-  if typ.returnType != nil:
-    var flags: TAssignmentFlags = {}
-    if typ.returnType.kind in {tyOpenArray, tyVarargs}:
-      # perhaps generate no temp if the call doesn't have side effects
-      flags.incl needTempForOpenArray
+  if typ[0] != nil:
    if isInvalidReturnType(p.config, typ):
      if params.len != 0: pl.add(", ")
      # beware of 'result = p(result)'. We may need to allocate a temporary:
      if d.k in {locTemp, locNone} or not preventNrvo(p, d.lode, le, ri):
        # Great, we can use 'd':
-        if d.k == locNone: d = getTemp(p, typ.returnType, needsInit=true)
+        if d.k == locNone: d = getTemp(p, typ[0], needsInit=true)
        elif d.k notin {locTemp} and not hasNoInit(ri):
          # reset before pass as 'result' var:
          discard "resetLoc(p, d)"
@@ -118,7 +97,7 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
        pl.add(");\n")
        line(p, cpsStmts, pl)
      else:
-        var tmp: TLoc = getTemp(p, typ.returnType, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ[0], needsInit=true)
        pl.add(addrLoc(p.config, tmp))
        pl.add(");\n")
        line(p, cpsStmts, pl)
@@ -132,56 +111,43 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
          # with them to prevent undefined behaviour and because the codegen
          # is free to emit expressions multiple times!
          d.k = locCall
-          d.snippet = pl
+          d.r = pl
          excl d.flags, lfSingleUse
        else:
-          if d.k == locNone and p.splitDecls == 0 and p.config.exc != excGoto:
-            d = getTempCpp(p, typ.returnType, pl)
+          if d.k == locNone and p.splitDecls == 0:
+            d = getTempCpp(p, typ[0], pl)
          else:
-            if d.k == locNone: d = getTemp(p, typ.returnType)
+            if d.k == locNone: d = getTemp(p, typ[0])
            var list = initLoc(locCall, d.lode, OnUnknown)
-            list.snippet = pl
-            genAssignment(p, d, list, {needAssignCall}) # no need for deep copying
+            list.r = pl
+            genAssignment(p, d, list, {}) # no need for deep copying
            if canRaise: raiseExit(p)

      elif isHarmlessStore(p, canRaise, d):
-        var useTemp = false
-        if d.k == locNone:
-          useTemp = true
-          d = getTemp(p, typ.returnType)
+        if d.k == locNone: d = getTemp(p, typ[0])
        assert(d.t != nil)        # generate an assignment to d:
        var list = initLoc(locCall, d.lode, OnUnknown)
-        list.snippet = pl
-        genAssignment(p, d, list, flags+{needAssignCall}) # no need for deep copying
-        if canRaise:
-          if not (useTemp and cleanupTemp(p, typ.returnType, d)):
-            raiseExit(p)
+        list.r = pl
+        genAssignment(p, d, list, {}) # no need for deep copying
+        if canRaise: raiseExit(p)
      else:
-        var tmp: TLoc = getTemp(p, typ.returnType, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ[0], needsInit=true)
        var list = initLoc(locCall, d.lode, OnUnknown)
-        list.snippet = pl
-        genAssignment(p, tmp, list, flags+{needAssignCall}) # no need for deep copying
-        if canRaise:
-          if not cleanupTemp(p, typ.returnType, tmp):
-            raiseExit(p)
+        list.r = pl
+        genAssignment(p, tmp, list, {}) # no need for deep copying
+        if canRaise: raiseExit(p)
        genAssignment(p, d, tmp, {})
  else:
    pl.add(");\n")
    line(p, cpsStmts, pl)
    if canRaise: raiseExit(p)

-proc genBoundsCheck(p: BProc; arr, a, b: TLoc; arrTyp: PType)
+proc genBoundsCheck(p: BProc; arr, a, b: TLoc)

 proc reifiedOpenArray(n: PNode): bool {.inline.} =
  var x = n
-  while true:
-    case x.kind
-    of {nkAddr, nkHiddenAddr, nkHiddenDeref}:
-      x = x[0]
-    of nkHiddenStdConv:
-      x = x[1]
-    else:
-      break
+  while x.kind in {nkAddr, nkHiddenAddr, nkHiddenStdConv, nkHiddenDeref}:
+    x = x[0]
  if x.kind == nkSym and x.sym.kind == skParam:
    result = false
  else:
@@ -191,15 +157,12 @@ proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareF
  var a = initLocExpr(p, q[1])
  var b = initLocExpr(p, q[2])
  var c = initLocExpr(p, q[3])
-  # bug #23321: In the function mapType, ptrs (tyPtr, tyVar, tyLent, tyRef)
-  # are mapped into ctPtrToArray, the dereference of which is skipped
-  # in the `genDeref`. We need to skip these ptrs here
-  let ty = skipTypes(a.t, abstractVar+{tyPtr, tyRef})
  # but first produce the required index checks:
  if optBoundsCheck in p.options:
-    genBoundsCheck(p, a, b, c, ty)
+    genBoundsCheck(p, a, b, c)
  if prepareForMutation:
    linefmt(p, cpsStmts, "#nimPrepareStrMutationV2($1);$n", [byRefLoc(p, a)])
+  let ty = skipTypes(a.t, abstractVar+{tyPtr})
  let dest = getTypeDesc(p.module, destType)
  let lengthExpr = "($1)-($2)+1" % [rdLoc(c), rdLoc(b)]
  case ty.kind
@@ -231,11 +194,11 @@ proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareF
      linefmt(p, cpsStmts, "#nimPrepareStrMutationV2($1);$n", [byRefLoc(p, a)])
    if atyp.kind in {tyVar} and not compileToCpp(p.module):
      result = ("(($5) ? (($4*)(*$1)$3+($2)) : NIM_NIL)" %
-                  [rdLoc(a), rdLoc(b), dataField(p), dest, dataFieldAccessor(p, "*" & rdLoc(a))],
+                  [rdLoc(a), rdLoc(b), dataField(p, ty.kind == tyString), dest, dataFieldAccessor(p, "*" & rdLoc(a))],
                lengthExpr)
    else:
      result = ("(($5) ? (($4*)$1$3+($2)) : NIM_NIL)" %
-                  [rdLoc(a), rdLoc(b), dataField(p), dest, dataFieldAccessor(p, rdLoc(a))],
+                  [rdLoc(a), rdLoc(b), dataField(p, ty.kind == tyString), dest, dataFieldAccessor(p, rdLoc(a))],
                lengthExpr)
  else:
    result = ("", "")
@@ -255,11 +218,12 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
        for i in 0..<q.len-1:
          genStmts(p, q[i])
        q = q.lastSon
-    let (x, y) = genOpenArraySlice(p, q, formalType, n.typ.elementType)
+    let (x, y) = genOpenArraySlice(p, q, formalType, n.typ[0])
    result.add x & ", " & y
  else:
    var a = initLocExpr(p, if n.kind == nkHiddenStdConv: n[1] else: n)
-    case skipTypes(a.t, abstractVar+{tyStatic}).kind
+    let typKind = skipTypes(a.t, abstractVar+{tyStatic}).kind
+    case typKind
    of tyOpenArray, tyVarargs:
      if reifiedOpenArray(n):
        if a.t.kind in {tyVar, tyLent}:
@@ -274,24 +238,26 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
          optSeqDestructors in p.config.globalOptions:
        linefmt(p, cpsStmts, "#nimPrepareStrMutationV2($1);$n", [byRefLoc(p, a)])
      if ntyp.kind in {tyVar} and not compileToCpp(p.module):
-        var t = TLoc(snippet: "(*$1)" % [a.rdLoc])
+        var t: TLoc
+        t.r = "(*$1)" % [a.rdLoc]
        result.add "($4) ? ((*$1)$3) : NIM_NIL, $2" %
-                     [a.rdLoc, lenExpr(p, t), dataField(p),
+                     [a.rdLoc, lenExpr(p, t, typKind == tyString), dataField(p, typKind == tyString),
                      dataFieldAccessor(p, "*" & a.rdLoc)]
      else:
        result.add "($4) ? ($1$3) : NIM_NIL, $2" %
-                     [a.rdLoc, lenExpr(p, a), dataField(p), dataFieldAccessor(p, a.rdLoc)]
+                     [a.rdLoc, lenExpr(p, a, typKind == tyString), dataField(p, typKind == tyString), dataFieldAccessor(p, a.rdLoc)]
    of tyArray:
      result.add "$1, $2" % [rdLoc(a), rope(lengthOrd(p.config, a.t))]
    of tyPtr, tyRef:
-      case elementType(a.t).kind
+      case lastSon(a.t).kind
      of tyString, tySequence:
-        var t = TLoc(snippet: "(*$1)" % [a.rdLoc])
+        var t: TLoc
+        t.r = "(*$1)" % [a.rdLoc]
        result.add "($4) ? ((*$1)$3) : NIM_NIL, $2" %
-                     [a.rdLoc, lenExpr(p, t), dataField(p),
+                     [a.rdLoc, lenExpr(p, t, typKind == tyString), dataField(p, typKind == tyString),
                      dataFieldAccessor(p, "*" & a.rdLoc)]
      of tyArray:
-        result.add "$1, $2" % [rdLoc(a), rope(lengthOrd(p.config, elementType(a.t)))]
+        result.add "$1, $2" % [rdLoc(a), rope(lengthOrd(p.config, lastSon(a.t)))]
      else:
        internalError(p.config, "openArrayLoc: " & typeToString(a.t))
    else: internalError(p.config, "openArrayLoc: " & typeToString(a.t))
@@ -307,7 +273,7 @@ proc withTmpIfNeeded(p: BProc, a: TLoc, needsTmp: bool): TLoc =
  else:
    result = a

-proc expressionsNeedsTmp(p: BProc, a: TLoc): TLoc =
+proc literalsNeedsTmp(p: BProc, a: TLoc): TLoc =
  result = getTemp(p, a.lode.typ, needsInit=false)
  genAssignment(p, result, a, {})

@@ -322,42 +288,27 @@ proc genArg(p: BProc, n: PNode, param: PSym; call: PNode; result: var Rope; need
  elif skipTypes(param.typ, abstractVar).kind in {tyOpenArray, tyVarargs}:
    var n = if n.kind != nkHiddenAddr: n else: n[0]
    openArrayLoc(p, param.typ, n, result)
-  elif ccgIntroducedPtr(p.config, param, call[0].typ.returnType) and
+  elif ccgIntroducedPtr(p.config, param, call[0].typ[0]) and
    (optByRef notin param.options or not p.module.compileToCpp):
    a = initLocExpr(p, n)
    if n.kind in {nkCharLit..nkNilLit}:
-      addAddrLoc(p.config, expressionsNeedsTmp(p, a), result)
+      addAddrLoc(p.config, literalsNeedsTmp(p, a), result)
    else:
      addAddrLoc(p.config, withTmpIfNeeded(p, a, needsTmp), result)
  elif p.module.compileToCpp and param.typ.kind in {tyVar} and
      n.kind == nkHiddenAddr:
-    # bug #23748: we need to introduce a temporary here. The expression type
-    # will be a reference in C++ and we cannot create a temporary reference
-    # variable. Thus, we create a temporary pointer variable instead.
-    let needsIndirect = mapType(p.config, n[0].typ, mapTypeChooser(n[0]) == skParam) != ctArray
-    if needsIndirect:
-      n.typ() = n.typ.exactReplica
-      n.typ.flags.incl tfVarIsPtr
-    a = initLocExprSingleUse(p, n)
-    a = withTmpIfNeeded(p, a, needsTmp)
-    if needsIndirect: a.flags.incl lfIndirect
+    a = initLocExprSingleUse(p, n[0])
    # if the proc is 'importc'ed but not 'importcpp'ed then 'var T' still
    # means '*T'. See posix.nim for lots of examples that do that in the wild.
    let callee = call[0]
    if callee.kind == nkSym and
        {sfImportc, sfInfixCall, sfCompilerProc} * callee.sym.flags == {sfImportc} and
-        {lfHeader, lfNoDecl} * callee.sym.loc.flags != {} and
-        needsIndirect:
+        {lfHeader, lfNoDecl} * callee.sym.loc.flags != {}:
      addAddrLoc(p.config, a, result)
    else:
      addRdLoc(a, result)
  else:
    a = initLocExprSingleUse(p, n)
-    if param.typ.kind in {tyVar, tyPtr, tyRef, tySink}:
-      let typ = skipTypes(param.typ, abstractPtrs)
-      if not sameBackendTypePickyAliases(typ, n.typ.skipTypes(abstractPtrs)):
-        a.snippet = "(($1) ($2))" %
-          [getTypeDesc(p.module, param.typ), rdCharLoc(a)]
    addRdLoc(withTmpIfNeeded(p, a, needsTmp), result)
  #assert result != nil

@@ -402,7 +353,7 @@ proc getPotentialWrites(n: PNode; mutate: bool; result: var seq[PNode]) =
  of nkCallKinds:
    case n.getMagic:
    of mIncl, mExcl, mInc, mDec, mAppendStrCh, mAppendStrStr, mAppendSeqElem,
-        mAddr, mNew, mNewFinalize, mWasMoved, mDestroy:
+        mAddr, mNew, mNewFinalize, mWasMoved, mDestroy, mReset:
      getPotentialWrites(n[1], true, result)
      for i in 2..<n.len:
        getPotentialWrites(n[i], mutate, result)
@@ -440,15 +391,13 @@ proc genParams(p: BProc, ri: PNode, typ: PType; result: var Rope) =
        if not needTmp[i - 1]:
          needTmp[i - 1] = potentialAlias(n, potentialWrites)
      getPotentialWrites(ri[i], false, potentialWrites)
-    when false:
-      # this optimization is wrong, see bug #23748
-      if ri[i].kind in {nkHiddenAddr, nkAddr}:
-        # Optimization: don't use a temp, if we would only take the address anyway
-        needTmp[i - 1] = false
+    if ri[i].kind in {nkHiddenAddr, nkAddr}:
+      # Optimization: don't use a temp, if we would only take the address anyway
+      needTmp[i - 1] = false

  var oldLen = result.len
  for i in 1..<ri.len:
-    if i < typ.n.len:
+    if i < typ.len:
      assert(typ.n[i].kind == nkSym)
      let paramType = typ.n[i]
      if not paramType.typ.isCompileTimeOnly:
@@ -473,6 +422,7 @@ proc genPrefixCall(p: BProc, le, ri: PNode, d: var TLoc) =
  # getUniqueType() is too expensive here:
  var typ = skipTypes(ri[0].typ, abstractInstOwned)
  assert(typ.kind == tyProc)
+  assert(typ.len == typ.n.len)

  var params = newRopeAppender()
  genParams(p, ri, typ, params)
@@ -495,6 +445,7 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
  # getUniqueType() is too expensive here:
  var typ = skipTypes(ri[0].typ, abstractInstOwned)
  assert(typ.kind == tyProc)
+  assert(typ.len == typ.n.len)

  var pl = newRopeAppender()
  genParams(p, ri, typ, pl)
@@ -507,14 +458,14 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =

  let rawProc = getClosureType(p.module, typ, clHalf)
  let canRaise = p.config.exc == excGoto and canRaiseDisp(p, ri[0])
-  if typ.returnType != nil:
+  if typ[0] != nil:
    if isInvalidReturnType(p.config, typ):
      if ri.len > 1: pl.add(", ")
      # beware of 'result = p(result)'. We may need to allocate a temporary:
      if d.k in {locTemp, locNone} or not preventNrvo(p, d.lode, le, ri):
        # Great, we can use 'd':
        if d.k == locNone:
-          d = getTemp(p, typ.returnType, needsInit=true)
+          d = getTemp(p, typ[0], needsInit=true)
        elif d.k notin {locTemp} and not hasNoInit(ri):
          # reset before pass as 'result' var:
          discard "resetLoc(p, d)"
@@ -522,29 +473,29 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
        genCallPattern()
        if canRaise: raiseExit(p)
      else:
-        var tmp: TLoc = getTemp(p, typ.returnType, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ[0], needsInit=true)
        pl.add(addrLoc(p.config, tmp))
        genCallPattern()
        if canRaise: raiseExit(p)
        genAssignment(p, d, tmp, {}) # no need for deep copying
    elif isHarmlessStore(p, canRaise, d):
-      if d.k == locNone: d = getTemp(p, typ.returnType)
+      if d.k == locNone: d = getTemp(p, typ[0])
      assert(d.t != nil)        # generate an assignment to d:
      var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
      if tfIterator in typ.flags:
-        list.snippet = PatIter % [rdLoc(op), pl, pl.addComma, rawProc]
+        list.r = PatIter % [rdLoc(op), pl, pl.addComma, rawProc]
      else:
-        list.snippet = PatProc % [rdLoc(op), pl, pl.addComma, rawProc]
+        list.r = PatProc % [rdLoc(op), pl, pl.addComma, rawProc]
      genAssignment(p, d, list, {}) # no need for deep copying
      if canRaise: raiseExit(p)
    else:
-      var tmp: TLoc = getTemp(p, typ.returnType)
+      var tmp: TLoc = getTemp(p, typ[0])
      assert(d.t != nil)        # generate an assignment to d:
      var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
      if tfIterator in typ.flags:
-        list.snippet = PatIter % [rdLoc(op), pl, pl.addComma, rawProc]
+        list.r = PatIter % [rdLoc(op), pl, pl.addComma, rawProc]
      else:
-        list.snippet = PatProc % [rdLoc(op), pl, pl.addComma, rawProc]
+        list.r = PatProc % [rdLoc(op), pl, pl.addComma, rawProc]
      genAssignment(p, tmp, list, {})
      if canRaise: raiseExit(p)
      genAssignment(p, d, tmp, {})
@@ -554,14 +505,14 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =

 proc genOtherArg(p: BProc; ri: PNode; i: int; typ: PType; result: var Rope;
                 argsCounter: var int) =
-  if i < typ.n.len:
+  if i < typ.len:
    # 'var T' is 'T&' in C++. This means we ignore the request of
    # any nkHiddenAddr when it's a 'var T'.
    let paramType = typ.n[i]
    assert(paramType.kind == nkSym)
    if paramType.typ.isCompileTimeOnly:
      discard
-    elif paramType.typ.kind in {tyVar} and ri[i].kind == nkHiddenAddr:
+    elif typ[i].kind in {tyVar} and ri[i].kind == nkHiddenAddr:
      if argsCounter > 0: result.add ", "
      genArgNoParam(p, ri[i][0], result)
      inc argsCounter
@@ -636,7 +587,7 @@ proc genThisArg(p: BProc; ri: PNode; i: int; typ: PType; result: var Rope) =
  # for better or worse c2nim translates the 'this' argument to a 'var T'.
  # However manual wrappers may also use 'ptr T'. In any case we support both
  # for convenience.
-  internalAssert p.config, i < typ.n.len
+  internalAssert p.config, i < typ.len
  assert(typ.n[i].kind == nkSym)
  # if the parameter is lying (tyVar) and thus we required an additional deref,
  # skip the deref:
@@ -726,27 +677,28 @@ proc genInfixCall(p: BProc, le, ri: PNode, d: var TLoc) =
  # getUniqueType() is too expensive here:
  var typ = skipTypes(ri[0].typ, abstractInst)
  assert(typ.kind == tyProc)
+  assert(typ.len == typ.n.len)
  # don't call '$' here for efficiency:
-  let pat = $ri[0].sym.loc.snippet
+  let pat = $ri[0].sym.loc.r
  internalAssert p.config, pat.len > 0
  if pat.contains({'#', '(', '@', '\''}):
    var pl = newRopeAppender()
    genPatternCall(p, ri, pat, typ, pl)
    # simpler version of 'fixupCall' that works with the pl+params combination:
    var typ = skipTypes(ri[0].typ, abstractInst)
-    if typ.returnType != nil:
+    if typ[0] != nil:
      if p.module.compileToCpp and lfSingleUse in d.flags:
        # do not generate spurious temporaries for C++! For C we're better off
        # with them to prevent undefined behaviour and because the codegen
        # is free to emit expressions multiple times!
        d.k = locCall
-        d.snippet = pl
+        d.r = pl
        excl d.flags, lfSingleUse
      else:
-        if d.k == locNone: d = getTemp(p, typ.returnType)
+        if d.k == locNone: d = getTemp(p, typ[0])
        assert(d.t != nil)        # generate an assignment to d:
        var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
-        list.snippet = pl
+        list.r = pl
        genAssignment(p, d, list, {}) # no need for deep copying
    else:
      pl.add(";\n")
@@ -756,9 +708,10 @@ proc genInfixCall(p: BProc, le, ri: PNode, d: var TLoc) =
    var argsCounter = 0
    if 1 < ri.len:
      genThisArg(p, ri, 1, typ, pl)
-    pl.add(op.snippet)
+    pl.add(op.r)
    var params = newRopeAppender()
    for i in 2..<ri.len:
+      assert(typ.len == typ.n.len)
      genOtherArg(p, ri, i, typ, params, argsCounter)
    fixupCall(p, le, ri, d, pl, params)

@@ -769,14 +722,15 @@ proc genNamedParamCall(p: BProc, ri: PNode, d: var TLoc) =
  # getUniqueType() is too expensive here:
  var typ = skipTypes(ri[0].typ, abstractInst)
  assert(typ.kind == tyProc)
+  assert(typ.len == typ.n.len)

  # don't call '$' here for efficiency:
-  let pat = $ri[0].sym.loc.snippet
+  let pat = $ri[0].sym.loc.r
  internalAssert p.config, pat.len > 0
  var start = 3
  if ' ' in pat:
    start = 1
-    pl.add(op.snippet)
+    pl.add(op.r)
    if ri.len > 1:
      pl.add(": ")
      genArg(p, ri[1], typ.n[1].sym, ri, pl)
@@ -785,12 +739,13 @@ proc genNamedParamCall(p: BProc, ri: PNode, d: var TLoc) =
    if ri.len > 1:
      genArg(p, ri[1], typ.n[1].sym, ri, pl)
      pl.add(" ")
-    pl.add(op.snippet)
+    pl.add(op.r)
    if ri.len > 2:
      pl.add(": ")
      genArg(p, ri[2], typ.n[2].sym, ri, pl)
  for i in start..<ri.len:
-    if i >= typ.n.len:
+    assert(typ.len == typ.n.len)
+    if i >= typ.len:
      internalError(p.config, ri.info, "varargs for objective C method?")
    assert(typ.n[i].kind == nkSym)
    var param = typ.n[i].sym
@@ -798,29 +753,29 @@ proc genNamedParamCall(p: BProc, ri: PNode, d: var TLoc) =
    pl.add(param.name.s)
    pl.add(": ")
    genArg(p, ri[i], param, ri, pl)
-  if typ.returnType != nil:
+  if typ[0] != nil:
    if isInvalidReturnType(p.config, typ):
      if ri.len > 1: pl.add(" ")
      # beware of 'result = p(result)'. We always allocate a temporary:
      if d.k in {locTemp, locNone}:
        # We already got a temp. Great, special case it:
-        if d.k == locNone: d = getTemp(p, typ.returnType, needsInit=true)
+        if d.k == locNone: d = getTemp(p, typ[0], needsInit=true)
        pl.add("Result: ")
        pl.add(addrLoc(p.config, d))
        pl.add("];\n")
        line(p, cpsStmts, pl)
      else:
-        var tmp: TLoc = getTemp(p, typ.returnType, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ[0], needsInit=true)
        pl.add(addrLoc(p.config, tmp))
        pl.add("];\n")
        line(p, cpsStmts, pl)
        genAssignment(p, d, tmp, {}) # no need for deep copying
    else:
      pl.add("]")
-      if d.k == locNone: d = getTemp(p, typ.returnType)
+      if d.k == locNone: d = getTemp(p, typ[0])
      assert(d.t != nil)        # generate an assignment to d:
      var list: TLoc = initLoc(locCall, ri, OnUnknown)
-      list.snippet = pl
+      list.r = pl
      genAssignment(p, d, list, {}) # no need for deep copying
  else:
    pl.add("];\n")
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
--- a/compiler/ccgliterals.nim
+++ b/compiler/ccgliterals.nim
@@ -94,6 +94,48 @@ proc genStringLiteralV2Const(m: BModule; n: PNode; isConst: bool; result: var Ro
    pureLit = m.tmpBase & rope(id)
  result.addf "{$1, (NimStrPayload*)&$2}", [rope(n.strVal.len), pureLit]

+# ------ Version 3: destructor based strings and seqs -----------------------
+# strings are enhanced by interned strings
+
+proc toConstLenV3(len: int): string =
+  result = rope((len shl 1) or 1)
+
+proc genStringLiteralDataOnlyV3(m: BModule, s: string; result: Rope; isConst: bool) =
+  # TODO: fixme: perhaps use makeCString for clarity for C
+  m.s[cfsStrData].addf("static $4 NIM_CHAR $1[$2] = $3;$n",
+       [result, rope(s.len), makeCCharArray(s),
+       rope(if isConst: "const" else: "")])
+
+proc genStringLiteralV3(m: BModule; n: PNode; isConst: bool; result: var Rope) =
+  let id = nodeTableTestOrSet(m.dataCache, n, m.labels)
+  if id == m.labels:
+    let pureLit = getTempName(m)
+    genStringLiteralDataOnlyV3(m, n.strVal, pureLit, isConst)
+    let tmp = getTempName(m)
+    result.add tmp
+    cgsym(m, "NimStringV3")
+    # string literal not found in the cache:
+    m.s[cfsStrData].addf("static $4 NimStringV3 $1 = {$2, (NIM_CHAR*)&$3};$n",
+          [tmp, toConstLenV3(n.strVal.len), pureLit, rope(if isConst: "const" else: "")])
+  else:
+    let tmp = getTempName(m)
+    result.add tmp
+    m.s[cfsStrData].addf("static $4 NimStringV3 $1 = {$2, (NIM_CHAR*)&$3};$n",
+          [tmp, toConstLenV3(n.strVal.len), m.tmpBase & rope(id),
+          rope(if isConst: "const" else: "")])
+
+proc genStringLiteralV3Const(m: BModule; n: PNode; isConst: bool; result: var Rope) =
+  let id = nodeTableTestOrSet(m.dataCache, n, m.labels)
+  var pureLit: Rope
+  if id == m.labels:
+    pureLit = getTempName(m)
+    cgsym(m, "NimStringV3")
+    # string literal not found in the cache:
+    genStringLiteralDataOnlyV3(m, n.strVal, pureLit, isConst)
+  else:
+    pureLit = m.tmpBase & rope(id)
+  result.addf "{$1, (NIM_CHAR*)&$2}", [toConstLenV3(n.strVal.len), pureLit]
+
 # ------ Version selector ---------------------------------------------------

 proc genStringLiteralDataOnly(m: BModule; s: string; info: TLineInfo;
@@ -104,6 +146,10 @@ proc genStringLiteralDataOnly(m: BModule; s: string; info: TLineInfo;
    let tmp = getTempName(m)
    genStringLiteralDataOnlyV2(m, s, tmp, isConst)
    result.add tmp
+  of 3:
+    let tmp = getTempName(m)
+    genStringLiteralDataOnlyV3(m, s, tmp, isConst)
+    result.add tmp
  else:
    localError(m.config, info, "cannot determine how to produce code for string literal")

@@ -114,5 +160,6 @@ proc genStringLiteral(m: BModule; n: PNode; result: var Rope) =
  case detectStrVersion(m)
  of 0, 1: genStringLiteralV1(m, n, result)
  of 2: genStringLiteralV2(m, n, isConst = true, result)
+  of 3: genStringLiteralV3(m, n, isConst = true, result)
  else:
    localError(m.config, n.info, "cannot determine how to produce code for string literal")
--- a/compiler/ccgreset.nim
+++ b/compiler/ccgreset.nim
@@ -24,10 +24,10 @@ proc specializeResetN(p: BProc, accessor: Rope, n: PNode;
  of nkRecCase:
    if (n[0].kind != nkSym): internalError(p.config, n.info, "specializeResetN")
    let disc = n[0].sym
-    if disc.loc.snippet == "": fillObjectFields(p.module, typ)
+    if disc.loc.r == "": fillObjectFields(p.module, typ)
    if disc.loc.t == nil:
      internalError(p.config, n.info, "specializeResetN()")
-    lineF(p, cpsStmts, "switch ($1.$2) {$n", [accessor, disc.loc.snippet])
+    lineF(p, cpsStmts, "switch ($1.$2) {$n", [accessor, disc.loc.r])
    for i in 1..<n.len:
      let branch = n[i]
      assert branch.kind in {nkOfBranch, nkElse}
@@ -38,14 +38,14 @@ proc specializeResetN(p: BProc, accessor: Rope, n: PNode;
      specializeResetN(p, accessor, lastSon(branch), typ)
      lineF(p, cpsStmts, "break;$n", [])
    lineF(p, cpsStmts, "} $n", [])
-    specializeResetT(p, "$1.$2" % [accessor, disc.loc.snippet], disc.loc.t)
+    specializeResetT(p, "$1.$2" % [accessor, disc.loc.r], disc.loc.t)
  of nkSym:
    let field = n.sym
    if field.typ.kind == tyVoid: return
-    if field.loc.snippet == "": fillObjectFields(p.module, typ)
+    if field.loc.r == "": fillObjectFields(p.module, typ)
    if field.loc.t == nil:
      internalError(p.config, n.info, "specializeResetN()")
-    specializeResetT(p, "$1.$2" % [accessor, field.loc.snippet], field.loc.t)
+    specializeResetT(p, "$1.$2" % [accessor, field.loc.r], field.loc.t)
  else: internalError(p.config, n.info, "specializeResetN()")

 proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
@@ -54,23 +54,24 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
  case typ.kind
  of tyGenericInst, tyGenericBody, tyTypeDesc, tyAlias, tyDistinct, tyInferred,
     tySink, tyOwned:
-    specializeResetT(p, accessor, skipModifier(typ))
+    specializeResetT(p, accessor, lastSon(typ))
  of tyArray:
-    let arraySize = lengthOrd(p.config, typ.indexType)
+    let arraySize = lengthOrd(p.config, typ[0])
    var i: TLoc = getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt))
    linefmt(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
-            [i.snippet, arraySize])
-    specializeResetT(p, ropecg(p.module, "$1[$2]", [accessor, i.snippet]), typ.elementType)
+            [i.r, arraySize])
+    specializeResetT(p, ropecg(p.module, "$1[$2]", [accessor, i.r]), typ[1])
    lineF(p, cpsStmts, "}$n", [])
  of tyObject:
-    var x = typ.baseClass
-    if x != nil: x = x.skipTypes(skipPtrs)
-    specializeResetT(p, accessor.parentObj(p.module), x)
+    for i in 0..<typ.len:
+      var x = typ[i]
+      if x != nil: x = x.skipTypes(skipPtrs)
+      specializeResetT(p, accessor.parentObj(p.module), x)
    if typ.n != nil: specializeResetN(p, accessor, typ.n, typ)
  of tyTuple:
    let typ = getUniqueType(typ)
-    for i, a in typ.ikids:
-      specializeResetT(p, ropecg(p.module, "$1.Field$2", [accessor, i]), a)
+    for i in 0..<typ.len:
+      specializeResetT(p, ropecg(p.module, "$1.Field$2", [accessor, i]), typ[i])

  of tyString, tyRef, tySequence:
    lineCg(p, cpsStmts, "#unsureAsgnRef((void**)&$1, NIM_NIL);$n", [accessor])
@@ -81,7 +82,7 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
      lineCg(p, cpsStmts, "$1.ClP_0 = NIM_NIL;$n", [accessor])
    else:
      lineCg(p, cpsStmts, "$1 = NIM_NIL;$n", [accessor])
-  of tyChar, tyBool, tyEnum, tyRange, tyInt..tyUInt64:
+  of tyChar, tyBool, tyEnum, tyInt..tyUInt64:
    lineCg(p, cpsStmts, "$1 = 0;$n", [accessor])
  of tyCstring, tyPointer, tyPtr, tyVar, tyLent:
    lineCg(p, cpsStmts, "$1 = NIM_NIL;$n", [accessor])
@@ -95,8 +96,8 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
    else:
      raiseAssert "unexpected set type kind"
  of tyNone, tyEmpty, tyNil, tyUntyped, tyTyped, tyGenericInvocation,
-      tyGenericParam, tyOrdinal, tyOpenArray, tyForward, tyVarargs,
-      tyUncheckedArray, tyError, tyBuiltInTypeClass, tyUserTypeClass,
+      tyGenericParam, tyOrdinal, tyRange, tyOpenArray, tyForward, tyVarargs,
+      tyUncheckedArray, tyProxy, tyBuiltInTypeClass, tyUserTypeClass,
      tyUserTypeClassInst, tyCompositeTypeClass, tyAnd, tyOr, tyNot,
      tyAnything, tyStatic, tyFromExpr, tyConcept, tyVoid, tyIterable:
    discard
--- a/compiler/ccgstmts.nim
+++ b/compiler/ccgstmts.nim
@@ -18,7 +18,7 @@ proc registerTraverseProc(p: BProc, v: PSym) =
  var traverseProc = ""
  if p.config.selectedGC in {gcMarkAndSweep, gcHooks, gcRefc} and
      optOwnedRefs notin p.config.globalOptions and
-      containsManagedMemory(v.loc.t):
+      containsGarbageCollectedRef(v.loc.t):
    # we register a specialized marked proc here; this has the advantage
    # that it works out of the box for thread local storage then :-)
    traverseProc = genTraverseProcForGlobal(p.module, v, v.info)
@@ -110,10 +110,10 @@ proc genVarTuple(p: BProc, n: PNode) =
      initLocalVar(p, v, immediateAsgn=isAssignedImmediately(p.config, n[^1]))
    var field = initLoc(locExpr, vn, tup.storage)
    if t.kind == tyTuple:
-      field.snippet = "$1.Field$2" % [rdLoc(tup), rope(i)]
+      field.r = "$1.Field$2" % [rdLoc(tup), rope(i)]
    else:
      if t.n[i].kind != nkSym: internalError(p.config, n.info, "genVarTuple")
-      field.snippet = "$1.$2" % [rdLoc(tup), mangleRecFieldName(p.module, t.n[i].sym)]
+      field.r = "$1.$2" % [rdLoc(tup), mangleRecFieldName(p.module, t.n[i].sym)]
    putLocIntoDest(p, v.loc, field)
    if forHcr or isGlobalInBlock:
      hcrGlobals.add((loc: v.loc, tp: "NULL"))
@@ -128,7 +128,7 @@ proc genVarTuple(p: BProc, n: PNode) =
    lineCg(p, cpsLocals, "NIM_BOOL $1 = NIM_FALSE;$n", [hcrCond])
    for curr in hcrGlobals:
      lineCg(p, cpsLocals, "$1 |= hcrRegisterGlobal($4, \"$2\", sizeof($3), $5, (void**)&$2);$N",
-              [hcrCond, curr.loc.snippet, rdLoc(curr.loc), getModuleDllPath(p.module, n[0].sym), curr.tp])
+              [hcrCond, curr.loc.r, rdLoc(curr.loc), getModuleDllPath(p.module, n[0].sym), curr.tp])


 proc loadInto(p: BProc, le, ri: PNode, a: var TLoc) {.inline.} =
@@ -267,11 +267,11 @@ proc genBreakState(p: BProc, n: PNode, d: var TLoc) =

  if n[0].kind == nkClosure:
    a = initLocExpr(p, n[0][1])
-    d.snippet = "(((NI*) $1)[1] < 0)" % [rdLoc(a)]
+    d.r = "(((NI*) $1)[1] < 0)" % [rdLoc(a)]
  else:
    a = initLocExpr(p, n[0])
    # the environment is guaranteed to contain the 'state' field at offset 1:
-    d.snippet = "((((NI*) $1.ClE_0)[1]) < 0)" % [rdLoc(a)]
+    d.r = "((((NI*) $1.ClE_0)[1]) < 0)" % [rdLoc(a)]

 proc genGotoVar(p: BProc; value: PNode) =
  if value.kind notin {nkCharLit..nkUInt64Lit}:
@@ -289,32 +289,22 @@ proc potentialValueInit(p: BProc; v: PSym; value: PNode; result: var Rope) =
    #echo "New code produced for ", v.name.s, " ", p.config $ value.info
    genBracedInit(p, value, isConst = false, v.typ, result)

-proc genCppParamsForCtor(p: BProc; call: PNode; didGenTemp: var bool): string =
+proc genCppParamsForCtor(p: BProc; call: PNode): string = 
  result = ""
  var argsCounter = 0
  let typ = skipTypes(call[0].typ, abstractInst)
  assert(typ.kind == tyProc)
  for i in 1..<call.len:
+    assert(typ.len == typ.n.len)
    #if it's a type we can just generate here another initializer as we are in an initializer context
    if call[i].kind == nkCall and call[i][0].kind == nkSym and call[i][0].sym.kind == skType:
      if argsCounter > 0: result.add ","
-      result.add genCppInitializer(p.module, p, call[i][0].sym.typ, didGenTemp)
+      result.add genCppInitializer(p.module, p, call[i][0].sym.typ)
    else:
-      #We need to test for temp in globals, see: #23657
-      let param =
-        if typ[i].kind in {tyVar} and call[i].kind == nkHiddenAddr:
-          call[i][0]
-        else:
-          call[i]
-      if param.kind != nkBracketExpr or param.typ.kind in
-        {tyRef, tyPtr, tyUncheckedArray, tyArray, tyOpenArray,
-          tyVarargs, tySequence, tyString, tyCstring, tyTuple}:
-        let tempLoc = initLocExprSingleUse(p, param)
-        didGenTemp = didGenTemp or tempLoc.k == locTemp
      genOtherArg(p, call, i, typ, result, argsCounter)

-proc genCppVarForCtor(p: BProc; call: PNode; decl: var Rope, didGenTemp: var bool) =
-  let params = genCppParamsForCtor(p, call, didGenTemp)
+proc genCppVarForCtor(p: BProc; call: PNode; decl: var Rope) =
+  let params = genCppParamsForCtor(p, call)
  if params.len == 0:
    decl = runtimeFormat("$#;\n", [decl])
  else:
@@ -341,14 +331,7 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
      # v.owner.kind != skModule:
      targetProc = p.module.preInitProc
    if isCppCtorCall and not containsHiddenPointer(v.typ):
-      var didGenTemp = false
-      callGlobalVarCppCtor(targetProc, v, vn, value, didGenTemp)
-      if didGenTemp:
-        message(p.config, vn.info, warnGlobalVarConstructorTemporary, vn.sym.name.s)
-        #We fail to call the constructor in the global scope so we do the call inside the main proc
-        assignGlobalVar(targetProc, vn, valueAsRope)
-        var loc = initLocExprSingleUse(targetProc, value)
-        genAssignment(targetProc, v.loc, loc, {})
+      callGlobalVarCppCtor(targetProc, v, vn, value)
    else:
      assignGlobalVar(targetProc, vn, valueAsRope)

@@ -383,15 +366,11 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
      var decl = localVarDecl(p, vn)
      var tmp: TLoc
      if isCppCtorCall:
-        var didGenTemp = false
-        genCppVarForCtor(p, value, decl, didGenTemp)
+        genCppVarForCtor(p, value, decl)
        line(p, cpsStmts, decl)
      else:
        tmp = initLocExprSingleUse(p, value)
-        if value.kind == nkEmpty:
-          lineF(p, cpsStmts, "$#;\n", [decl])
-        else:
-          lineF(p, cpsStmts, "$# = $#;\n", [decl, tmp.rdLoc])
+        lineF(p, cpsStmts, "$# = $#;\n", [decl, tmp.rdLoc])
      return
    assignLocalVar(p, vn)
    initLocalVar(p, v, imm)
@@ -405,7 +384,7 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
    # put it in the locals section - mainly because of loops which
    # use the var in a call to resetLoc() in the statements section
    lineCg(targetProc, cpsLocals, "hcrRegisterGlobal($3, \"$1\", sizeof($2), $4, (void**)&$1);$n",
-           [v.loc.snippet, rdLoc(v.loc), getModuleDllPath(p.module, v), traverseProc])
+           [v.loc.r, rdLoc(v.loc), getModuleDllPath(p.module, v), traverseProc])
    # nothing special left to do later on - let's avoid closing and reopening blocks
    forHcr = false

@@ -414,7 +393,7 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
  # be able to re-run it but without the top level code - just the init of globals
  if forHcr:
    lineCg(targetProc, cpsStmts, "if (hcrRegisterGlobal($3, \"$1\", sizeof($2), $4, (void**)&$1))$N",
-           [v.loc.snippet, rdLoc(v.loc), getModuleDllPath(p.module, v), traverseProc])
+           [v.loc.r, rdLoc(v.loc), getModuleDllPath(p.module, v), traverseProc])
    startBlock(targetProc)
  if value.kind != nkEmpty and valueAsRope.len == 0:
    genLineDir(targetProc, vn)
@@ -755,18 +734,6 @@ proc raiseExit(p: BProc) =
      lineCg(p, cpsStmts, "if (NIM_UNLIKELY(*nimErr_)) goto LA$1_;$n",
        [p.nestedTryStmts[^1].label])

-proc raiseExitCleanup(p: BProc, destroy: string) =
-  assert p.config.exc == excGoto
-  if nimErrorFlagDisabled notin p.flags:
-    p.flags.incl nimErrorFlagAccessed
-    if p.nestedTryStmts.len == 0:
-      p.flags.incl beforeRetNeeded
-      # easy case, simply goto 'ret':
-      lineCg(p, cpsStmts, "if (NIM_UNLIKELY(*nimErr_)) {$1; goto BeforeRet_;}$n", [destroy])
-    else:
-      lineCg(p, cpsStmts, "if (NIM_UNLIKELY(*nimErr_)) {$2; goto LA$1_;}$n",
-        [p.nestedTryStmts[^1].label, destroy])
-
 proc finallyActions(p: BProc) =
  if p.config.exc != excGoto and p.nestedTryStmts.len > 0 and p.nestedTryStmts[^1].inExcept:
    # if the current try stmt have a finally block,
@@ -796,14 +763,10 @@ proc genRaiseStmt(p: BProc, t: PNode) =
    var e = rdLoc(a)
    discard getTypeDesc(p.module, t[0].typ)
    var typ = skipTypes(t[0].typ, abstractPtrs)
-    case p.config.exc
-    of excCpp:
+    # XXX For reasons that currently escape me, this is only required by the new
+    # C++ based exception handling:
+    if p.config.exc == excCpp:
      blockLeaveActions(p, howManyTrys = 0, howManyExcepts = p.inExceptBlockLen)
-    of excGoto:
-      blockLeaveActions(p, howManyTrys = 0,
-        howManyExcepts = (if p.nestedTryStmts.len > 0 and p.nestedTryStmts[^1].inExcept: 1 else: 0))
-    else:
-      discard
    genLineDir(p, t)
    if isImportedException(typ, p.config):
      lineF(p, cpsStmts, "throw $1;$n", [e])
@@ -1075,8 +1038,8 @@ proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =

  inc(p.labels, 2)
  let etmp = p.labels
-  #init on locals, fixes #23306
-  lineCg(p, cpsLocals, "std::exception_ptr T$1_;$n", [etmp])
+
+  lineCg(p, cpsStmts, "std::exception_ptr T$1_;$n", [etmp])

  let fin = if t[^1].kind == nkFinally: t[^1] else: nil
  p.nestedTryStmts.add((fin, false, 0.Natural))
@@ -1526,12 +1489,7 @@ proc genTrySetjmp(p: BProc, t: PNode, d: var TLoc) =

 proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
  var res = ""
-  let offset =
-    if isAsmStmt: 1 # first son is pragmas
-    else: 0
-
-  for i in offset..<t.len:
-    let it = t[i]
+  for it in t.sons:
    case it.kind
    of nkStrLit..nkTripleStrLit:
      res.add(it.strVal)
@@ -1545,7 +1503,7 @@ proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
      else:
        discard getTypeDesc(p.module, skipTypes(sym.typ, abstractPtrs))
        fillBackendName(p.module, sym)
-        res.add($sym.loc.snippet)
+        res.add($sym.loc.r)
    of nkTypeOfExpr:
      res.add($getTypeDesc(p.module, it.typ))
    else:
@@ -1575,21 +1533,6 @@ proc genAsmStmt(p: BProc, t: PNode) =
  assert(t.kind == nkAsmStmt)
  genLineDir(p, t)
  var s = newRopeAppender()
-
-  var asmSyntax = ""
-  if (let p = t[0]; p.kind == nkPragma):
-    for i in p:
-      if whichPragma(i) == wAsmSyntax:
-        asmSyntax = i[1].strVal
-
-  if asmSyntax != "" and
-     not (
-      asmSyntax == "gcc" and hasGnuAsm in CC[p.config.cCompiler].props or
-      asmSyntax == "vcc" and hasGnuAsm notin CC[p.config.cCompiler].props):
-    localError(
-      p.config, t.info,
-      "Your compiler does not support the specified inline assembler")
-
  genAsmOrEmitStmt(p, t, isAsmStmt=true, s)
  # see bug #2362, "top level asm statements" seem to be a mis-feature
  # but even if we don't do this, the example in #2362 cannot possibly
@@ -1627,9 +1570,9 @@ proc genPragma(p: BProc, n: PNode) =
    case whichPragma(it)
    of wEmit: genEmit(p, it)
    of wPush:
-      processPushBackendOption(p.config, p.optionsStack, p.options, n, i+1)
+      processPushBackendOption(p.optionsStack, p.options, n, i+1)
    of wPop:
-      processPopBackendOption(p.config, p.optionsStack, p.options)
+      processPopBackendOption(p.optionsStack, p.options)
    else: discard


--- a/compiler/ccgthreadvars.nim
+++ b/compiler/ccgthreadvars.nim
@@ -30,7 +30,7 @@ proc declareThreadVar(m: BModule, s: PSym, isExtern: bool) =
    # allocator for it :-(
    if not containsOrIncl(m.g.nimtvDeclared, s.id):
      m.g.nimtvDeps.add(s.loc.t)
-      m.g.nimtv.addf("$1 $2;$n", [getTypeDesc(m, s.loc.t), s.loc.snippet])
+      m.g.nimtv.addf("$1 $2;$n", [getTypeDesc(m, s.loc.t), s.loc.r])
  else:
    if isExtern: m.s[cfsVars].add("extern ")
    elif lfExportLib in s.loc.flags: m.s[cfsVars].add("N_LIB_EXPORT_VAR ")
@@ -41,7 +41,7 @@ proc declareThreadVar(m: BModule, s: PSym, isExtern: bool) =
        m.s[cfsVars].add("NIM_THREAD_LOCAL ")
      else: m.s[cfsVars].add("NIM_THREADVAR ")
    m.s[cfsVars].add(getTypeDesc(m, s.loc.t))
-    m.s[cfsVars].addf(" $1;$n", [s.loc.snippet])
+    m.s[cfsVars].addf(" $1;$n", [s.loc.r])

 proc generateThreadLocalStorage(m: BModule) =
  if m.g.nimtv != "" and (usesThreadVars in m.flags or sfMainModule in m.module.flags):
--- a/compiler/ccgtrav.nim
+++ b/compiler/ccgtrav.nim
@@ -34,10 +34,10 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, n: PNode;
    if (n[0].kind != nkSym): internalError(c.p.config, n.info, "genTraverseProc")
    var p = c.p
    let disc = n[0].sym
-    if disc.loc.snippet == "": fillObjectFields(c.p.module, typ)
+    if disc.loc.r == "": fillObjectFields(c.p.module, typ)
    if disc.loc.t == nil:
      internalError(c.p.config, n.info, "genTraverseProc()")
-    lineF(p, cpsStmts, "switch ($1.$2) {$n", [accessor, disc.loc.snippet])
+    lineF(p, cpsStmts, "switch ($1.$2) {$n", [accessor, disc.loc.r])
    for i in 1..<n.len:
      let branch = n[i]
      assert branch.kind in {nkOfBranch, nkElse}
@@ -51,10 +51,10 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, n: PNode;
  of nkSym:
    let field = n.sym
    if field.typ.kind == tyVoid: return
-    if field.loc.snippet == "": fillObjectFields(c.p.module, typ)
+    if field.loc.r == "": fillObjectFields(c.p.module, typ)
    if field.loc.t == nil:
      internalError(c.p.config, n.info, "genTraverseProc()")
-    genTraverseProc(c, "$1.$2" % [accessor, field.loc.snippet], field.loc.t)
+    genTraverseProc(c, "$1.$2" % [accessor, field.loc.r], field.loc.t)
  else: internalError(c.p.config, n.info, "genTraverseProc()")

 proc parentObj(accessor: Rope; m: BModule): Rope {.inline.} =
@@ -71,36 +71,37 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType) =
  case typ.kind
  of tyGenericInst, tyGenericBody, tyTypeDesc, tyAlias, tyDistinct, tyInferred,
     tySink, tyOwned:
-    genTraverseProc(c, accessor, skipModifier(typ))
+    genTraverseProc(c, accessor, lastSon(typ))
  of tyArray:
-    let arraySize = lengthOrd(c.p.config, typ.indexType)
+    let arraySize = lengthOrd(c.p.config, typ[0])
    var i: TLoc = getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt))
    var oldCode = p.s(cpsStmts)
    freeze oldCode
    linefmt(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
-            [i.snippet, arraySize])
+            [i.r, arraySize])
    let oldLen = p.s(cpsStmts).len
-    genTraverseProc(c, ropecg(c.p.module, "$1[$2]", [accessor, i.snippet]), typ.elementType)
+    genTraverseProc(c, ropecg(c.p.module, "$1[$2]", [accessor, i.r]), typ[1])
    if p.s(cpsStmts).len == oldLen:
      # do not emit dummy long loops for faster debug builds:
      p.s(cpsStmts) = oldCode
    else:
      lineF(p, cpsStmts, "}$n", [])
  of tyObject:
-    var x = typ.baseClass
-    if x != nil: x = x.skipTypes(skipPtrs)
-    genTraverseProc(c, accessor.parentObj(c.p.module), x)
+    for i in 0..<typ.len:
+      var x = typ[i]
+      if x != nil: x = x.skipTypes(skipPtrs)
+      genTraverseProc(c, accessor.parentObj(c.p.module), x)
    if typ.n != nil: genTraverseProc(c, accessor, typ.n, typ)
  of tyTuple:
    let typ = getUniqueType(typ)
-    for i, a in typ.ikids:
-      genTraverseProc(c, ropecg(c.p.module, "$1.Field$2", [accessor, i]), a)
+    for i in 0..<typ.len:
+      genTraverseProc(c, ropecg(c.p.module, "$1.Field$2", [accessor, i]), typ[i])
  of tyRef:
    lineCg(p, cpsStmts, visitorFrmt, [accessor, c.visitorFrmt])
  of tySequence:
    if optSeqDestructors notin c.p.module.config.globalOptions:
      lineCg(p, cpsStmts, visitorFrmt, [accessor, c.visitorFrmt])
-    elif containsGarbageCollectedRef(typ.elementType):
+    elif containsGarbageCollectedRef(typ.lastSon):
      # destructor based seqs are themselves not traced but their data is, if
      # they contain a GC'ed type:
      lineCg(p, cpsStmts, "#nimGCvisitSeq((void*)$1, $2);$n", [accessor, c.visitorFrmt])
@@ -117,15 +118,15 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType) =
 proc genTraverseProcSeq(c: TTraversalClosure, accessor: Rope, typ: PType) =
  var p = c.p
  assert typ.kind == tySequence
-  var i = getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt))
+  var i: TLoc = getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt))
  var oldCode = p.s(cpsStmts)
  freeze oldCode
-  var a = TLoc(snippet: accessor)
+  var a: TLoc = TLoc(r: accessor)

  lineF(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
-      [i.snippet, lenExpr(c.p, a)])
+      [i.r, lenExpr(c.p, a)])
  let oldLen = p.s(cpsStmts).len
-  genTraverseProc(c, "$1$3[$2]" % [accessor, i.snippet, dataField(c.p)], typ.elementType)
+  genTraverseProc(c, "$1$3[$2]" % [accessor, i.r, dataField(c.p)], typ[0])
  if p.s(cpsStmts).len == oldLen:
    # do not emit dummy long loops for faster debug builds:
    p.s(cpsStmts) = oldCode
@@ -133,6 +134,7 @@ proc genTraverseProcSeq(c: TTraversalClosure, accessor: Rope, typ: PType) =
    lineF(p, cpsStmts, "}$n", [])

 proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
+  var c: TTraversalClosure
  var p = newProc(nil, m)
  result = "Marker_" & getTypeName(m, origTyp, sig)
  let
@@ -145,19 +147,18 @@ proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
  lineF(p, cpsLocals, "$1 a;$n", [t])
  lineF(p, cpsInit, "a = ($1)p;$n", [t])

-  var c = TTraversalClosure(p: p,
-    visitorFrmt: "op" # "#nimGCvisit((void*)$1, op);$n"
-    )
+  c.p = p
+  c.visitorFrmt = "op" # "#nimGCvisit((void*)$1, op);$n"

  assert typ.kind != tyTypeDesc
  if typ.kind == tySequence:
    genTraverseProcSeq(c, "a".rope, typ)
  else:
-    if skipTypes(typ.elementType, typedescInst+{tyOwned}).kind == tyArray:
+    if skipTypes(typ[0], typedescInst+{tyOwned}).kind == tyArray:
      # C's arrays are broken beyond repair:
-      genTraverseProc(c, "a".rope, typ.elementType)
+      genTraverseProc(c, "a".rope, typ[0])
    else:
-      genTraverseProc(c, "(*a)".rope, typ.elementType)
+      genTraverseProc(c, "(*a)".rope, typ[0])

  let generatedProc = "$1 {$n$2$3$4}\n" %
        [header, p.s(cpsLocals), p.s(cpsInit), p.s(cpsStmts)]
@@ -173,6 +174,7 @@ proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
 proc genTraverseProcForGlobal(m: BModule, s: PSym; info: TLineInfo): Rope =
  discard genTypeInfoV1(m, s.loc.t, info)

+  var c: TTraversalClosure
  var p = newProc(nil, m)
  var sLoc = rdLoc(s.loc)
  result = getTempName(m)
@@ -181,10 +183,8 @@ proc genTraverseProcForGlobal(m: BModule, s: PSym; info: TLineInfo): Rope =
    accessThreadLocalVar(p, s)
    sLoc = "NimTV_->" & sLoc

-  var c = TTraversalClosure(p: p,
-    visitorFrmt: "0" # "#nimGCvisit((void*)$1, 0);$n"
-  )
-
+  c.visitorFrmt = "0" # "#nimGCvisit((void*)$1, 0);$n"
+  c.p = p
  let header = "static N_NIMCALL(void, $1)(void)" % [result]
  genTraverseProc(c, sLoc, s.loc.t)

--- a/compiler/ccgtypes.nim
+++ b/compiler/ccgtypes.nim
@@ -55,41 +55,24 @@ proc mangleField(m: BModule; name: PIdent): string =
  if isKeyword(name):
    result.add "_0"

-proc mangleProc(m: BModule; s: PSym; makeUnique: bool): string =
-  result = "_Z"  # Common prefix in Itanium ABI
-  var params = ""
-  var staticLists = ""
-  if s.typ.len > 1: #we dont care about the return param
-    for i in 1..<s.typ.len:
-      if s.typ[i].isNil: continue
-      params.add encodeType(m, s.typ[i], staticLists)
-
-  result.add encodeSym(m, s, makeUnique, staticLists)
-  result.add params
-
-  if result in m.g.mangledPrcs:
-    result = mangleProc(m, s, true)
-  else:
-    m.g.mangledPrcs.incl(result)
-
 proc fillBackendName(m: BModule; s: PSym) =
-  if s.loc.snippet == "":
-    var result: Rope
-    if not m.compileToCpp and s.kind in routineKinds and optCDebug in m.g.config.globalOptions and
-      m.g.config.symbolFiles == disabledSf:
-      result = mangleProc(m, s, false).rope
-    else:
-      result = s.name.s.mangle.rope
-      result.add mangleProcNameExt(m.g.graph, s)
+  if s.loc.r == "":
+    var result = s.name.s.mangle.rope
+    result.add "__"
+    result.add m.g.graph.ifaces[s.itemId.module].uniqueName
+    result.add "_u"
+    result.addInt s.itemId.item # s.disamb #
    if m.hcrOn:
      result.add '_'
      result.add(idOrSig(s, m.module.name.s.mangle, m.sigConflicts, m.config))
-    s.loc.snippet = result
+    s.loc.r = result
+    writeMangledName(m.ndi, s, m.config)

 proc fillParamName(m: BModule; s: PSym) =
-  if s.loc.snippet == "":
+  if s.loc.r == "":
    var res = s.name.s.mangle
-    res.add mangleParamExt(s)
+    res.add "_p"
+    res.addInt s.position
    #res.add idOrSig(s, res, m.sigConflicts, m.config)
    # Take into account if HCR is on because of the following scenario:
    #   if a module gets imported and it has some more importc symbols in it,
@@ -107,22 +90,24 @@ proc fillParamName(m: BModule; s: PSym) =
    # and a function called in main or proxy uses `socket` as a parameter name.
    # That would lead to either needing to reload `proxy` or to overwrite the
    # executable file for the main module, which is running (or both!) -> error.
-    s.loc.snippet = res.rope
+    s.loc.r = res.rope
+    writeMangledName(m.ndi, s, m.config)

 proc fillLocalName(p: BProc; s: PSym) =
  assert s.kind in skLocalVars+{skTemp}
  #assert sfGlobal notin s.flags
-  if s.loc.snippet == "":
+  if s.loc.r == "":
    var key = s.name.s.mangle
    let counter = p.sigConflicts.getOrDefault(key)
    var result = key.rope
    if s.kind == skTemp:
      # speed up conflict search for temps (these are quite common):
      if counter != 0: result.add "_" & rope(counter+1)
-    elif s.kind != skResult:
+    elif counter != 0 or isKeyword(s.name) or p.module.g.config.cppDefines.contains(key):
      result.add "_" & rope(counter+1)
    p.sigConflicts.inc(key)
-    s.loc.snippet = result
+    s.loc.r = result
+    if s.kind != skTemp: writeMangledName(p.module.ndi, s, p.config)

 proc scopeMangledParam(p: BProc; param: PSym) =
  ## parameter generation only takes BModule, not a BProc, so we have to
@@ -148,23 +133,23 @@ proc getTypeName(m: BModule; typ: PType; sig: SigHash): Rope =
  var t = typ
  while true:
    if t.sym != nil and {sfImportc, sfExportc} * t.sym.flags != {}:
-      return t.sym.loc.snippet
+      return t.sym.loc.r

    if t.kind in irrelevantForBackend:
-      t = t.skipModifier
+      t = t.lastSon
    else:
      break
-  let typ = if typ.kind in {tyAlias, tySink, tyOwned}: typ.elementType else: typ
-  if typ.loc.snippet == "":
-    typ.typeName(typ.loc.snippet)
-    typ.loc.snippet.add $sig
+  let typ = if typ.kind in {tyAlias, tySink, tyOwned}: typ.lastSon else: typ
+  if typ.loc.r == "":
+    typ.typeName(typ.loc.r)
+    typ.loc.r.add $sig
  else:
    when defined(debugSigHashes):
      # check consistency:
      var tn = newRopeAppender()
      typ.typeName(tn)
-      assert($typ.loc.snippet == $(tn & $sig))
-  result = typ.loc.snippet
+      assert($typ.loc.r == $(tn & $sig))
+  result = typ.loc.r
  if result == "": internalError(m.config, "getTypeName: " & $typ.kind)

 proc mapSetType(conf: ConfigRef; typ: PType): TCTypeKind =
@@ -190,10 +175,10 @@ proc mapType(conf: ConfigRef; typ: PType; isParam: bool): TCTypeKind =
  of tyObject, tyTuple: result = ctStruct
  of tyUserTypeClasses:
    doAssert typ.isResolvedUserTypeClass
-    result = mapType(conf, typ.skipModifier, isParam)
+    return mapType(conf, typ.lastSon, isParam)
  of tyGenericBody, tyGenericInst, tyGenericParam, tyDistinct, tyOrdinal,
     tyTypeDesc, tyAlias, tySink, tyInferred, tyOwned:
-    result = mapType(conf, skipModifier(typ), isParam)
+    result = mapType(conf, lastSon(typ), isParam)
  of tyEnum:
    if firstOrd(conf, typ) < 0:
      result = ctInt32
@@ -204,9 +189,9 @@ proc mapType(conf: ConfigRef; typ: PType; isParam: bool): TCTypeKind =
      of 4: result = ctInt32
      of 8: result = ctInt64
      else: result = ctInt32
-  of tyRange: result = mapType(conf, typ.elementType, isParam)
+  of tyRange: result = mapType(conf, typ[0], isParam)
  of tyPtr, tyVar, tyLent, tyRef:
-    var base = skipTypes(typ.elementType, typedescInst)
+    var base = skipTypes(typ.lastSon, typedescInst)
    case base.kind
    of tyOpenArray, tyArray, tyVarargs, tyUncheckedArray: result = ctPtrToArray
    of tySet:
@@ -221,7 +206,7 @@ proc mapType(conf: ConfigRef; typ: PType; isParam: bool): TCTypeKind =
  of tyInt..tyUInt64:
    result = TCTypeKind(ord(typ.kind) - ord(tyInt) + ord(ctInt))
  of tyStatic:
-    if typ.n != nil: result = mapType(conf, typ.skipModifier, isParam)
+    if typ.n != nil: result = mapType(conf, lastSon typ, isParam)
    else:
      result = ctVoid
      doAssert(false, "mapType: " & $typ.kind)
@@ -246,11 +231,12 @@ proc isImportedCppType(t: PType): bool =
 proc isOrHasImportedCppType(typ: PType): bool =
  searchTypeFor(typ.skipTypes({tyRef}), isImportedCppType)

-proc hasNoInit(t: PType): bool =
-  result = t.sym != nil and sfNoInit in t.sym.flags
-
 proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDescKind): Rope

+proc isObjLackingTypeField(typ: PType): bool {.inline.} =
+  result = (typ.kind == tyObject) and ((tfFinal in typ.flags) and
+      (typ[0] == nil) or isPureObject(typ))
+
 proc isInvalidReturnType(conf: ConfigRef; typ: PType, isProc = true): bool =
  # Arrays and sets cannot be returned by a C procedure, because C is
  # such a poor programming language.
@@ -271,15 +257,9 @@ proc isInvalidReturnType(conf: ConfigRef; typ: PType, isProc = true): bool =
          {tyVar, tyLent, tyRef, tyPtr})
    of ctStruct:
      let t = skipTypes(rettype, typedescInst)
-      if rettype.isImportedCppType or t.isImportedCppType or
-          (typ.callConv == ccCDecl and conf.selectedGC in {gcArc, gcAtomicArc, gcOrc}):
-        # prevents nrvo for cdecl procs; # bug #23401
-        result = false
-      else:
-        result = containsGarbageCollectedRef(t) or
-            (t.kind == tyObject and not isObjLackingTypeField(t)) or
-            (getSize(conf, rettype) == szUnknownSize and (t.sym == nil or sfImportc notin t.sym.flags))
-
+      if rettype.isImportedCppType or t.isImportedCppType: return false
+      result = containsGarbageCollectedRef(t) or
+          (t.kind == tyObject and not isObjLackingTypeField(t))
    else: result = false

 const
@@ -287,9 +267,7 @@ const
    "N_STDCALL", "N_CDECL", "N_SAFECALL",
    "N_SYSCALL", # this is probably not correct for all platforms,
                 # but one can #define it to what one wants
-    "N_INLINE", "N_NOINLINE", "N_FASTCALL", "N_THISCALL", "N_CLOSURE", "N_NOCONV",
-    "N_NOCONV" #ccMember is N_NOCONV
-    ]
+    "N_INLINE", "N_NOINLINE", "N_FASTCALL", "N_THISCALL", "N_CLOSURE", "N_NOCONV"]

 proc cacheGetType(tab: TypeCache; sig: SigHash): Rope =
  # returns nil if we need to declare this type
@@ -318,7 +296,7 @@ proc fillResult(conf: ConfigRef; param: PNode, proctype: PType) =
 proc typeNameOrLiteral(m: BModule; t: PType, literal: string): Rope =
  if t.sym != nil and sfImportc in t.sym.flags and t.sym.magic == mNone:
    useHeader(m, t.sym)
-    result = t.sym.loc.snippet
+    result = t.sym.loc.r
  else:
    result = rope(literal)

@@ -333,6 +311,9 @@ proc getSimpleTypeDesc(m: BModule; typ: PType): Rope =
    result = typeNameOrLiteral(m, typ, "void*")
  of tyString:
    case detectStrVersion(m)
+    of 3:
+      cgsym(m, "NimStringV3")
+      result = typeNameOrLiteral(m, typ, "NimStringV3")
    of 2:
      cgsym(m, "NimStrPayload")
      cgsym(m, "NimStringV2")
@@ -346,19 +327,14 @@ proc getSimpleTypeDesc(m: BModule; typ: PType): Rope =
  of tyNil: result = typeNameOrLiteral(m, typ, "void*")
  of tyInt..tyUInt64:
    result = typeNameOrLiteral(m, typ, NumericalTypeToStr[typ.kind])
-  of tyRange, tyOrdinal: result = getSimpleTypeDesc(m, typ.skipModifier)
-  of tyDistinct:
-    result = getSimpleTypeDesc(m, typ.skipModifier)
-    if isImportedType(typ) and result != "":
-      useHeader(m, typ.sym)
-      result = typ.sym.loc.snippet
+  of tyDistinct, tyRange, tyOrdinal: result = getSimpleTypeDesc(m, typ[0])
  of tyStatic:
-    if typ.n != nil: result = getSimpleTypeDesc(m, skipModifier typ)
+    if typ.n != nil: result = getSimpleTypeDesc(m, lastSon typ)
    else:
      result = ""
      internalError(m.config, "tyStatic for getSimpleTypeDesc")
  of tyGenericInst, tyAlias, tySink, tyOwned:
-    result = getSimpleTypeDesc(m, skipModifier typ)
+    result = getSimpleTypeDesc(m, lastSon typ)
  else: result = ""

  if result != "" and typ.isImportedType():
@@ -378,6 +354,13 @@ proc getTypePre(m: BModule; typ: PType; sig: SigHash): Rope =
    result = getSimpleTypeDesc(m, typ)
    if result == "": result = cacheGetType(m.typeCache, sig)

+proc structOrUnion(t: PType): Rope =
+  let cachedUnion = rope("union")
+  let cachedStruct = rope("struct")
+  let t = t.skipTypes({tyAlias, tySink})
+  if tfUnion in t.flags: cachedUnion
+  else: cachedStruct
+
 proc addForwardStructFormat(m: BModule; structOrUnion: Rope, typename: Rope) =
  if m.compileToCpp:
    m.s[cfsForwardTypes].addf "$1 $2;$n", [structOrUnion, typename]
@@ -476,8 +459,8 @@ macro unrollChars(x: static openArray[char], name, body: untyped) =
      copy body
    )))

-proc multiFormat*(frmt: var string, chars: static openArray[char], args: openArray[seq[string]]) =
-  var res: string
+proc multiFormat*(frmt: var string, chars : static openArray[char], args: openArray[seq[string]]) =
+  var res : string
  unrollChars(chars, c):
    res = ""
    let arg = args[find(chars, c)]
@@ -519,16 +502,15 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, name, params
                   weakDep=false;) =
  let t = prc.typ
  let isCtor = sfConstructor in prc.flags
-  if isCtor or (name[0] == '~' and sfMember in prc.flags):
-    # destructors can't have void
+  if isCtor or (name[0] == '~' and sfMember in prc.flags): #destructors cant have void
    rettype = ""
-  elif t.returnType == nil or isInvalidReturnType(m.config, t):
+  elif t[0] == nil or isInvalidReturnType(m.config, t):
    rettype = "void"
  else:
    if rettype == "":
-      rettype = getTypeDescAux(m, t.returnType, check, dkResult)
+      rettype = getTypeDescAux(m, t[0], check, dkResult)
    else:
-      rettype = runtimeFormat(rettype.replace("'0", "$1"), [getTypeDescAux(m, t.returnType, check, dkResult)])
+      rettype = runtimeFormat(rettype.replace("'0", "$1"), [getTypeDescAux(m, t[0], check, dkResult)])
  var types, names, args: seq[string] = @[]
  if not isCtor:
    var this = t.n[1].sym
@@ -536,10 +518,10 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, name, params
    fillLoc(this.loc, locParam, t.n[1],
            this.paramStorageLoc)
    if this.typ.kind == tyPtr:
-      this.loc.snippet = "this"
+      this.loc.r = "this"
    else:
-      this.loc.snippet = "(*this)"
-    names.add this.loc.snippet
+      this.loc.r = "(*this)"
+    names.add this.loc.r
    types.add getTypeDescWeak(m, this.typ, check, dkParam)

  let firstParam = if isCtor: 1 else: 2
@@ -552,11 +534,11 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, name, params
        descKind = dkRefGenericParam
      else:
        descKind = dkRefParam
-    var typ, name: string
+    var typ, name : string
    fillParamName(m, param)
    fillLoc(param.loc, locParam, t.n[i],
            param.paramStorageLoc)
-    if ccgIntroducedPtr(m.config, param, t.returnType) and descKind == dkParam:
+    if ccgIntroducedPtr(m.config, param, t[0]) and descKind == dkParam:
      typ = getTypeDescWeak(m, param.typ, check, descKind) & "*"
      incl(param.loc.flags, lfIndirect)
      param.loc.storage = OnUnknown
@@ -567,7 +549,7 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, name, params
    if sfNoalias in param.flags:
      typ.add("NIM_NOALIAS ")

-    name = param.loc.snippet
+    name = param.loc.r
    types.add typ
    names.add name
    if sfCodegenDecl notin param.flags:
@@ -594,10 +576,10 @@ proc genProcParams(m: BModule; t: PType, rettype, params: var Rope,
                   check: var IntSet, declareEnvironment=true;
                   weakDep=false;) =
  params = "("
-  if t.returnType == nil or isInvalidReturnType(m.config, t):
+  if t[0] == nil or isInvalidReturnType(m.config, t):
    rettype = "void"
  else:
-    rettype = getTypeDescWeak(m, t.returnType, check, dkResult)
+    rettype = getTypeDescAux(m, t[0], check, dkResult)
  for i in 1..<t.n.len:
    if t.n[i].kind != nkSym: internalError(m.config, t.n.info, "genProcParams")
    var param = t.n[i].sym
@@ -613,7 +595,7 @@ proc genProcParams(m: BModule; t: PType, rettype, params: var Rope,
    fillLoc(param.loc, locParam, t.n[i],
            param.paramStorageLoc)
    var typ: Rope
-    if ccgIntroducedPtr(m.config, param, t.returnType) and descKind == dkParam:
+    if ccgIntroducedPtr(m.config, param, t[0]) and descKind == dkParam:
      typ = (getTypeDescWeak(m, param.typ, check, descKind))
      typ.add("*")
      incl(param.loc.flags, lfIndirect)
@@ -627,24 +609,24 @@ proc genProcParams(m: BModule; t: PType, rettype, params: var Rope,
      typ.add("NIM_NOALIAS ")
    if sfCodegenDecl notin param.flags:
      params.add(typ)
-      params.add(param.loc.snippet)
+      params.add(param.loc.r)
    else:
-      params.add runtimeFormat(param.cgDeclFrmt, [typ, param.loc.snippet])
+      params.add runtimeFormat(param.cgDeclFrmt, [typ, param.loc.r])
    # declare the len field for open arrays:
    var arr = param.typ.skipTypes({tyGenericInst})
-    if arr.kind in {tyVar, tyLent, tySink}: arr = arr.elementType
+    if arr.kind in {tyVar, tyLent, tySink}: arr = arr.lastSon
    var j = 0
    while arr.kind in {tyOpenArray, tyVarargs}:
      # this fixes the 'sort' bug:
      if param.typ.kind in {tyVar, tyLent}: param.loc.storage = OnUnknown
      # need to pass hidden parameter:
-      params.addf(", NI $1Len_$2", [param.loc.snippet, j.rope])
+      params.addf(", NI $1Len_$2", [param.loc.r, j.rope])
      inc(j)
      arr = arr[0].skipTypes({tySink})
-  if t.returnType != nil and isInvalidReturnType(m.config, t):
-    var arr = t.returnType
+  if t[0] != nil and isInvalidReturnType(m.config, t):
+    var arr = t[0]
    if params != "(": params.add(", ")
-    if mapReturnType(m.config, arr) != ctArray:
+    if mapReturnType(m.config, t[0]) != ctArray:
      if isHeaderFile in m.flags:
        # still generates types for `--header`
        params.add(getTypeDescAux(m, arr, check, dkResult))
@@ -666,7 +648,7 @@ proc genProcParams(m: BModule; t: PType, rettype, params: var Rope,

 proc mangleRecFieldName(m: BModule; field: PSym): Rope =
  if {sfImportc, sfExportc} * field.flags != {}:
-    result = field.loc.snippet
+    result = field.loc.r
  else:
    result = rope(mangleField(m, field.name))
  if result == "": internalError(m.config, field.info, "mangleRecFieldName")
@@ -678,9 +660,9 @@ proc hasCppCtor(m: BModule; typ: PType): bool =
      if sfConstructor in prc.flags:
        return true

-proc genCppParamsForCtor(p: BProc; call: PNode; didGenTemp: var bool): string
+proc genCppParamsForCtor(p: BProc; call: PNode): string

-proc genCppInitializer(m: BModule, prc: BProc; typ: PType; didGenTemp: var bool): string =
+proc genCppInitializer(m: BModule, prc: BProc; typ: PType): string =
  #To avoid creating a BProc per test when called inside a struct nil BProc is allowed
  result = "{}"
  if typ.itemId in m.g.graph.initializersPerType:
@@ -689,13 +671,13 @@ proc genCppInitializer(m: BModule, prc: BProc; typ: PType; didGenTemp: var bool)
      var p = prc
      if p == nil:
        p = BProc(module: m)
-      result = "{" & genCppParamsForCtor(p, call, didGenTemp) & "}"
+      result = "{" & genCppParamsForCtor(p, call) & "}"
      if prc == nil:
        assert p.blocks.len == 0, "BProc belongs to a struct doesnt have blocks"

 proc genRecordFieldsAux(m: BModule; n: PNode,
                        rectype: PType,
-                        check: var IntSet; result: var Builder; unionPrefix = "") =
+                        check: var IntSet; result: var Rope; unionPrefix = "") =
  case n.kind
  of nkRecList:
    for i in 0..<n.len:
@@ -712,51 +694,63 @@ proc genRecordFieldsAux(m: BModule; n: PNode,
        let k = lastSon(n[i])
        if k.kind != nkSym:
          let structName = "_" & mangleRecFieldName(m, n[0].sym) & "_" & $i
-          var a = newBuilder("")
+          var a = newRopeAppender()
          genRecordFieldsAux(m, k, rectype, check, a, unionPrefix & $structName & ".")
-          if a.len != 0:
-            unionBody.addFieldWithStructType(m, rectype, structName):
-              unionBody.add(a)
+          if a != "":
+            if tfPacked notin rectype.flags:
+              unionBody.add("struct {")
+            else:
+              if hasAttribute in CC[m.config.cCompiler].props:
+                unionBody.add("struct __attribute__((__packed__)){")
+              else:
+                unionBody.addf("#pragma pack(push, 1)$nstruct{", [])
+            unionBody.add(a)
+            unionBody.addf("} $1;$n", [structName])
+            if tfPacked in rectype.flags and hasAttribute notin CC[m.config.cCompiler].props:
+              unionBody.addf("#pragma pack(pop)$n", [])
        else:
          genRecordFieldsAux(m, k, rectype, check, unionBody, unionPrefix)
      else: internalError(m.config, "genRecordFieldsAux(record case branch)")
-    if unionBody.len != 0:
-      result.addAnonUnion:
-        result.add(unionBody)
+    if unionBody != "":
+      result.addf("union{\n$1};$n", [unionBody])
  of nkSym:
    let field = n.sym
    if field.typ.kind == tyVoid: return
    #assert(field.ast == nil)
    let sname = mangleRecFieldName(m, field)
    fillLoc(field.loc, locField, n, unionPrefix & sname, OnUnknown)
+    if field.alignment > 0:
+      result.addf "NIM_ALIGN($1) ", [rope(field.alignment)]
    # for importcpp'ed objects, we only need to set field.loc, but don't
    # have to recurse via 'getTypeDescAux'. And not doing so prevents problems
    # with heavily templatized C++ code:
    if not isImportedCppType(rectype):
+      let noAlias = if sfNoalias in field.flags: " NIM_NOALIAS" else: ""
+
      let fieldType = field.loc.lode.typ.skipTypes(abstractInst)
-      var typ: Rope = ""
-      var isFlexArray = false
-      var initializer = ""
      if fieldType.kind == tyUncheckedArray:
-        typ = getTypeDescAux(m, fieldType.elemType, check, dkField)
-        isFlexArray = true
+        result.addf("\t$1 $2[SEQ_DECL_SIZE];$n",
+            [getTypeDescAux(m, fieldType.elemType, check, dkField), sname])
      elif fieldType.kind == tySequence:
        # we need to use a weak dependency here for trecursive_table.
-        typ = getTypeDescWeak(m, field.loc.t, check, dkField)
+        result.addf("\t$1$3 $2;$n", [getTypeDescWeak(m, field.loc.t, check, dkField), sname, noAlias])
+      elif field.bitsize != 0:
+        result.addf("\t$1$4 $2:$3;$n", [getTypeDescAux(m, field.loc.t, check, dkField), sname, rope($field.bitsize), noAlias])
      else:
-        typ = getTypeDescAux(m, field.loc.t, check, dkField)
        # don't use fieldType here because we need the
        # tyGenericInst for C++ template support
        let noInit = sfNoInit in field.flags or (field.typ.sym != nil and sfNoInit in field.typ.sym.flags)
        if not noInit and (fieldType.isOrHasImportedCppType() or hasCppCtor(m, field.owner.typ)):
-          var didGenTemp = false
-          initializer = genCppInitializer(m, nil, fieldType, didGenTemp)
-      result.addField(field, sname, typ, isFlexArray, initializer)
+          var initializer = genCppInitializer(m, nil, fieldType)
+          result.addf("\t$1$3 $2$4;$n", [getTypeDescAux(m, field.loc.t, check, dkField), sname, noAlias, initializer])
+        else:
+          result.addf("\t$1$3 $2;$n", [getTypeDescAux(m, field.loc.t, check, dkField), sname, noAlias])
  else: internalError(m.config, n.info, "genRecordFieldsAux()")

 proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool = false, isFwdDecl:bool = false)

-proc addRecordFields(result: var Builder; m: BModule; typ: PType, check: var IntSet) =
+proc getRecordFields(m: BModule; typ: PType, check: var IntSet): Rope =
+  result = newRopeAppender()
  genRecordFieldsAux(m, typ.n, typ, check, result)
  if typ.itemId in m.g.graph.memberProcsPerType:
    let procs = m.g.graph.memberProcsPerType[typ.itemId]
@@ -771,43 +765,95 @@ proc addRecordFields(result: var Builder; m: BModule; typ: PType, check: var Int
      genMemberProcHeader(m, prc, header, false, true)
      result.addf "$1;$n", [header]
    if isCtorGen and not isDefaultCtorGen:
-      var ch: IntSet = default(IntSet)
+      var ch: IntSet
      result.addf "$1() = default;$n", [getTypeDescAux(m, typ, ch, dkOther)]

 proc fillObjectFields*(m: BModule; typ: PType) =
  # sometimes generic objects are not consistently merged. We patch over
  # this fact here.
  var check = initIntSet()
-  var ignored = newBuilder("")
-  addRecordFields(ignored, m, typ, check)
-  if typ.baseClass != nil:
-    fillObjectFields(m, typ.baseClass.skipTypes(skipPtrs))
+  discard getRecordFields(m, typ, check)

 proc mangleDynLibProc(sym: PSym): Rope

+proc getRecordDescAux(m: BModule; typ: PType, name, baseType: Rope,
+                   check: var IntSet, hasField:var bool): Rope =
+  result = ""
+  if typ.kind == tyObject:
+    if typ[0] == nil:
+      if lacksMTypeField(typ):
+        appcg(m, result, " {$n", [])
+      else:
+        if optTinyRtti in m.config.globalOptions:
+          appcg(m, result, " {$n#TNimTypeV2* m_type;$n", [])
+        else:
+          appcg(m, result, " {$n#TNimType* m_type;$n", [])
+        hasField = true
+    elif m.compileToCpp:
+      appcg(m, result, " : public $1 {$n", [baseType])
+      if typ.isException and m.config.exc == excCpp:
+        when false:
+          appcg(m, result, "virtual void raise() { throw *this; }$n", []) # required for polymorphic exceptions
+          if typ.sym.magic == mException:
+            # Add cleanup destructor to Exception base class
+            appcg(m, result, "~$1();$n", [name])
+            # define it out of the class body and into the procs section so we don't have to
+            # artificially forward-declare popCurrentExceptionEx (very VERY troublesome for HCR)
+            appcg(m, cfsProcs, "inline $1::~$1() {if(this->raiseId) #popCurrentExceptionEx(this->raiseId);}$n", [name])
+      hasField = true
+    else:
+      appcg(m, result, " {$n  $1 Sup;$n", [baseType])
+      hasField = true
+  else:
+    result.addf(" {$n", [name])
+
 proc getRecordDesc(m: BModule; typ: PType, name: Rope,
                   check: var IntSet): Rope =
  # declare the record:
-  var baseType: string = ""
-  if typ.baseClass != nil:
-    baseType = getTypeDescAux(m, typ.baseClass.skipTypes(skipPtrs), check, dkField)
-  if typ.sym == nil or sfCodegenDecl notin typ.sym.flags:
-    result = newBuilder("")
-    result.addStruct(m, typ, name, baseType):
-      result.addRecordFields(m, typ, check)
+  var hasField = false
+  var structOrUnion: string
+  if tfPacked in typ.flags:
+      if hasAttribute in CC[m.config.cCompiler].props:
+        structOrUnion = structOrUnion(typ) & " __attribute__((__packed__))"
+      else:
+        structOrUnion = "#pragma pack(push, 1)\L" & structOrUnion(typ)
  else:
-    var desc = newBuilder("")
-    desc.addRecordFields(m, typ, check)
+    structOrUnion = structOrUnion(typ)
+  var baseType: string = ""
+  if typ[0] != nil:
+    baseType = getTypeDescAux(m, typ[0].skipTypes(skipPtrs), check, dkField)
+  if typ.sym == nil or sfCodegenDecl notin typ.sym.flags:
+    result = structOrUnion & " " & name
+    result.add(getRecordDescAux(m, typ, name, baseType, check, hasField))
+    let desc = getRecordFields(m, typ, check)
+    if not hasField and typ.itemId notin m.g.graph.memberProcsPerType:
+      if desc == "":
+        result.add("\tchar dummy;\n")
+      elif typ.len == 1 and typ.n[0].kind == nkSym:
+        let field = typ.n[0].sym
+        let fieldType = field.typ.skipTypes(abstractInst)
+        if fieldType.kind == tyUncheckedArray:
+          result.add("\tchar dummy;\n")
+      result.add(desc)
+    else:
+      result.add(desc)
+    result.add("};\L")
+  else:
+    let desc = getRecordFields(m, typ, check)
    result = runtimeFormat(typ.sym.cgDeclFrmt, [name, desc, baseType])
+  if tfPacked in typ.flags and hasAttribute notin CC[m.config.cCompiler].props:
+    result.add "#pragma pack(pop)\L"

 proc getTupleDesc(m: BModule; typ: PType, name: Rope,
                  check: var IntSet): Rope =
-  result = newBuilder("")
-  result.addStruct(m, typ, name, ""):
-    for i, a in typ.ikids:
-      result.addField(
-        name = "Field" & $i,
-        typ = getTypeDescAux(m, a, check, dkField))
+  result = "$1 $2 {$n" % [structOrUnion(typ), name]
+  var desc: Rope = ""
+  for i in 0..<typ.len:
+    desc.addf("$1 Field$2;$n",
+         [getTypeDescAux(m, typ[i], check, dkField), rope(i)])
+  if desc == "": result.add("char dummy;\L")
+  else: result.add(desc)
+  result.add("};\L")

 proc scanCppGenericSlot(pat: string, cursor, outIdx, outStars: var int): bool =
  # A helper proc for handling cppimport patterns, involving numeric
@@ -829,25 +875,25 @@ proc scanCppGenericSlot(pat: string, cursor, outIdx, outStars: var int): bool =
 proc resolveStarsInCppType(typ: PType, idx, stars: int): PType =
  # Make sure the index refers to one of the generic params of the type.
  # XXX: we should catch this earlier and report it as a semantic error.
-  if idx >= typ.kidsLen:
+  if idx >= typ.len:
    raiseAssert "invalid apostrophe type parameter index"

  result = typ[idx]
  for i in 1..stars:
-    if result != nil and result.kidsLen > 0:
-      result = if result.kind == tyGenericInst: result[FirstGenericParamAt]
+    if result != nil and result.len > 0:
+      result = if result.kind == tyGenericInst: result[1]
               else: result.elemType

 proc getOpenArrayDesc(m: BModule; t: PType, check: var IntSet; kind: TypeDescKind): Rope =
  let sig = hashType(t, m.config)
  if kind == dkParam:
-    result = getTypeDescWeak(m, t.elementType, check, kind) & "*"
+    result = getTypeDescWeak(m, t[0], check, kind) & "*"
  else:
    result = cacheGetType(m.typeCache, sig)
    if result == "":
      result = getTypeName(m, t, sig)
      m.typeCache[sig] = result
-      let elemType = getTypeDescWeak(m, t.elementType, check, kind)
+      let elemType = getTypeDescWeak(m, t[0], check, kind)
      m.s[cfsTypes].addf("typedef struct {$n$2* Field0;$nNI Field1;$n} $1;$n",
                         [result, elemType])

@@ -864,12 +910,12 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
  if t != origTyp and origTyp.sym != nil: useHeader(m, origTyp.sym)
  let sig = hashType(origTyp, m.config)

-  # tyDistinct matters if it is an importc type
-  result = getTypePre(m, origTyp.skipTypes(irrelevantForBackend-{tyOwned, tyDistinct}), sig)
+  result = "" # todo move `result = getTypePre(m, t, sig)` here ?
  defer: # defer is the simplest in this case
    if isImportedType(t) and not m.typeABICache.containsOrIncl(sig):
      addAbiCheck(m, t, result)

+  result = getTypePre(m, t, sig)
  if result != "" and t.kind != tyOpenArray:
    excl(check, t.id)
    if kind == dkRefParam or kind == dkRefGenericParam and origTyp.kind == tyGenericInst:
@@ -879,7 +925,7 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
  of tyRef, tyPtr, tyVar, tyLent:
    var star = if t.kind in {tyVar} and tfVarIsPtr notin origTyp.flags and
                    compileToCpp(m): "&" else: "*"
-    var et = origTyp.skipTypes(abstractInst).elementType
+    var et = origTyp.skipTypes(abstractInst).lastSon
    var etB = et.skipTypes(abstractInst)
    if mapType(m.config, t, kind == dkParam) == ctPtrToArray and (etB.kind != tyOpenArray or kind == dkParam):
      if etB.kind == tySet:
@@ -971,7 +1017,7 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
      assert(cacheGetType(m.typeCache, sig) == "")
      m.typeCache[sig] = result & seqStar(m)
      if not isImportedType(t):
-        if skipTypes(t.elementType, typedescInst).kind != tyEmpty:
+        if skipTypes(t[0], typedescInst).kind != tyEmpty:
          const
            cppSeq = "struct $2 : #TGenericSeq {$n"
            cSeq = "struct $2 {$n" &
@@ -979,11 +1025,11 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
          if m.compileToCpp:
            appcg(m, m.s[cfsSeqTypes],
                cppSeq & "  $1 data[SEQ_DECL_SIZE];$n" &
-                "};$n", [getTypeDescAux(m, t.elementType, check, kind), result])
+                "};$n", [getTypeDescAux(m, t[0], check, kind), result])
          else:
            appcg(m, m.s[cfsSeqTypes],
                cSeq & "  $1 data[SEQ_DECL_SIZE];$n" &
-                "};$n", [getTypeDescAux(m, t.elementType, check, kind), result])
+                "};$n", [getTypeDescAux(m, t[0], check, kind), result])
        else:
          result = rope("TGenericSeq")
      result.add(seqStar(m))
@@ -991,7 +1037,7 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
    result = getTypeName(m, origTyp, sig)
    m.typeCache[sig] = result
    if not isImportedType(t):
-      let foo = getTypeDescAux(m, t.elementType, check, kind)
+      let foo = getTypeDescAux(m, t[0], check, kind)
      m.s[cfsTypes].addf("typedef $1 $2[1];$n", [foo, result])
  of tyArray:
    var n: BiggestInt = toInt64(lengthOrd(m.config, t))
@@ -999,9 +1045,9 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
    result = getTypeName(m, origTyp, sig)
    m.typeCache[sig] = result
    if not isImportedType(t):
-      let e = getTypeDescAux(m, t.elementType, check, kind)
+      let foo = getTypeDescAux(m, t[1], check, kind)
      m.s[cfsTypes].addf("typedef $1 $2[$3];$n",
-           [e, result, rope(n)])
+           [foo, result, rope(n)])
  of tyObject, tyTuple:
    let tt = origTyp.skipTypes({tyDistinct})
    if isImportedCppType(t) and tt.kind == tyGenericInst:
@@ -1036,9 +1082,9 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
        result.add cppName.substr(chunkStart)
      else:
        result = cppNameAsRope & "<"
-        for needsComma, a in tt.genericInstParams:
-          if needsComma: result.add(" COMMA ")
-          addResultType(a)
+        for i in 1..<tt.len-1:
+          if i > 1: result.add(" COMMA ")
+          addResultType(tt[i])
        result.add("> ")
      # always call for sideeffects:
      assert t.kind != tyTuple
@@ -1069,8 +1115,8 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
  of tySet:
    # Don't use the imported name as it may be scoped: 'Foo::SomeKind'
    result = rope("tySet_")
-    t.elementType.typeName(result)
-    result.add $t.elementType.hashType(m.config)
+    t.lastSon.typeName(result)
+    result.add $t.lastSon.hashType(m.config)
    m.typeCache[sig] = result
    if not isImportedType(t):
      let s = int(getSize(m.config, t))
@@ -1080,7 +1126,7 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
             [result, rope(getSize(m.config, t))])
  of tyGenericInst, tyDistinct, tyOrdinal, tyTypeDesc, tyAlias, tySink, tyOwned,
     tyUserTypeClass, tyUserTypeClassInst, tyInferred:
-    result = getTypeDescAux(m, skipModifier(t), check, kind)
+    result = getTypeDescAux(m, lastSon(t), check, kind)
  else:
    internalError(m.config, "getTypeDescAux(" & $t.kind & ')')
    result = ""
@@ -1132,15 +1178,12 @@ proc isReloadable(m: BModule; prc: PSym): bool =
 proc isNonReloadable(m: BModule; prc: PSym): bool =
  return m.hcrOn and sfNonReloadable in prc.flags

-proc parseVFunctionDecl(val: string; name, params, retType, superCall: var string; isFnConst, isOverride, isMemberVirtual, isStatic: var bool; isCtor: bool, isFunctor=false) =
+proc parseVFunctionDecl(val: string; name, params, retType, superCall: var string; isFnConst, isOverride, isMemberVirtual: var bool; isCtor: bool, isFunctor=false) =
  var afterParams: string = ""
  if scanf(val, "$*($*)$s$*", name, params, afterParams):
    if name.strip() == "operator" and params == "": #isFunctor?
-      parseVFunctionDecl(afterParams, name, params, retType, superCall, isFnConst, isOverride, isMemberVirtual, isStatic, isCtor, true)
+      parseVFunctionDecl(afterParams, name, params, retType, superCall, isFnConst, isOverride, isMemberVirtual, isCtor, true)
      return
-    if name.find("static ") > -1:
-      isStatic = true
-      name = name.replace("static ", "")
    isFnConst = afterParams.find("const") > -1
    isOverride = afterParams.find("override") > -1
    isMemberVirtual = name.find("virtual ") > -1
@@ -1155,7 +1198,7 @@ proc parseVFunctionDecl(val: string; name, params, retType, superCall: var strin

  params = "(" & params & ")"

-proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool = false, isFwdDecl: bool = false) =
+proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool = false, isFwdDecl : bool = false) =
  assert sfCppMember * prc.flags != {}
  let isCtor = sfConstructor in prc.flags
  var check = initIntSet()
@@ -1164,17 +1207,17 @@ proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool =
  var memberOp = "#." #only virtual
  var typ: PType
  if isCtor:
-    typ = prc.typ.returnType
+    typ = prc.typ[0]
  else:
-    typ = prc.typ.firstParamType
+    typ = prc.typ[1]
  if typ.kind == tyPtr:
-    typ = typ.elementType
+    typ = typ[0]
    memberOp = "#->"
  var typDesc = getTypeDescWeak(m, typ, check, dkParam)
  let asPtrStr = rope(if asPtr: "_PTR" else: "")
  var name, params, rettype, superCall: string = ""
-  var isFnConst, isOverride, isMemberVirtual, isStatic: bool = false
-  parseVFunctionDecl(prc.constraint.strVal, name, params, rettype, superCall, isFnConst, isOverride, isMemberVirtual, isStatic, isCtor)
+  var isFnConst, isOverride, isMemberVirtual: bool = false
+  parseVFunctionDecl(prc.constraint.strVal, name, params, rettype, superCall, isFnConst, isOverride, isMemberVirtual, isCtor)
  genMemberProcParams(m, prc, superCall, rettype, name, params, check, true, false)
  let isVirtual = sfVirtual in prc.flags or isMemberVirtual
  var fnConst, override: string = ""
@@ -1183,8 +1226,6 @@ proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool =
  if isFnConst:
    fnConst = " const"
  if isFwdDecl:
-    if isStatic:
-      result.add "static "
    if isVirtual:
      rettype = "virtual " & rettype
      if isOverride:
@@ -1192,7 +1233,7 @@ proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool =
    superCall = ""
  else:
    if not isCtor:
-      prc.loc.snippet = "$1$2(@)" % [memberOp, name]
+      prc.loc.r = "$1$2(@)" % [memberOp, name]
    elif superCall != "":
      superCall = " : " & superCall

@@ -1213,7 +1254,7 @@ proc genProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool = false)
  # handle the 2 options for hotcodereloading codegen - function pointer
  # (instead of forward declaration) or header for function body with "_actual" postfix
  let asPtrStr = rope(if asPtr: "_PTR" else: "")
-  var name = prc.loc.snippet
+  var name = prc.loc.r
  if not asPtr and isReloadable(m, prc):
    name.add("_actual")
  # careful here! don't access ``prc.ast`` as that could reload large parts of
@@ -1295,8 +1336,8 @@ proc genTypeInfoAuxBase(m: BModule; typ, origType: PType;
 proc genTypeInfoAux(m: BModule; typ, origType: PType, name: Rope;
                    info: TLineInfo) =
  var base: Rope
-  if typ.hasElementType and typ.last != nil:
-    var x = typ.last
+  if typ.len > 0 and typ.lastSon != nil:
+    var x = typ.lastSon
    if typ.kind == tyObject: x = x.skipTypes(skipPtrs)
    if typ.kind == tyPtr and x.kind == tyObject and incompleteType(x):
      base = rope("0")
@@ -1353,13 +1394,13 @@ proc genObjectFields(m: BModule; typ, origType: PType, n: PNode, expr: Rope;
    var tmp = discriminatorTableName(m, typ, field)
    var L = lengthOrd(m.config, field.typ)
    assert L > 0
-    if field.loc.snippet == "": fillObjectFields(m, typ)
+    if field.loc.r == "": fillObjectFields(m, typ)
    if field.loc.t == nil:
      internalError(m.config, n.info, "genObjectFields")
    m.s[cfsTypeInit3].addf("$1.kind = 3;$n" &
        "$1.offset = offsetof($2, $3);$n" & "$1.typ = $4;$n" &
        "$1.name = $5;$n" & "$1.sons = &$6[0];$n" &
-        "$1.len = $7;$n", [expr, getTypeDesc(m, origType, dkVar), field.loc.snippet,
+        "$1.len = $7;$n", [expr, getTypeDesc(m, origType, dkVar), field.loc.r,
                           genTypeInfoV1(m, field.typ, info),
                           makeCString(field.name.s),
                           tmp, rope(L)])
@@ -1391,38 +1432,41 @@ proc genObjectFields(m: BModule; typ, origType: PType, n: PNode, expr: Rope;
    # Do not produce code for void types
    if isEmptyType(field.typ): return
    if field.bitsize == 0:
-      if field.loc.snippet == "": fillObjectFields(m, typ)
+      if field.loc.r == "": fillObjectFields(m, typ)
      if field.loc.t == nil:
        internalError(m.config, n.info, "genObjectFields")
      m.s[cfsTypeInit3].addf("$1.kind = 1;$n" &
          "$1.offset = offsetof($2, $3);$n" & "$1.typ = $4;$n" &
          "$1.name = $5;$n", [expr, getTypeDesc(m, origType, dkVar),
-          field.loc.snippet, genTypeInfoV1(m, field.typ, info), makeCString(field.name.s)])
+          field.loc.r, genTypeInfoV1(m, field.typ, info), makeCString(field.name.s)])
  else: internalError(m.config, n.info, "genObjectFields")

 proc genObjectInfo(m: BModule; typ, origType: PType, name: Rope; info: TLineInfo) =
-  assert typ.kind == tyObject
-  if incompleteType(typ):
-    localError(m.config, info, "request for RTTI generation for incomplete object: " &
-                      typeToString(typ))
-  genTypeInfoAux(m, typ, origType, name, info)
+  if typ.kind == tyObject:
+    if incompleteType(typ):
+      localError(m.config, info, "request for RTTI generation for incomplete object: " &
+                        typeToString(typ))
+    genTypeInfoAux(m, typ, origType, name, info)
+  else:
+    genTypeInfoAuxBase(m, typ, origType, name, rope("0"), info)
  var tmp = getNimNode(m)
-  if (not isImportedType(typ)) or tfCompleteStruct in typ.flags:
+  if not isImportedType(typ):
    genObjectFields(m, typ, origType, typ.n, tmp, info)
  m.s[cfsTypeInit3].addf("$1.node = &$2;$n", [tiNameForHcr(m, name), tmp])
-  var t = typ.baseClass
+  var t = typ[0]
  while t != nil:
    t = t.skipTypes(skipPtrs)
    t.flags.incl tfObjHasKids
-    t = t.baseClass
+    t = t[0]

 proc genTupleInfo(m: BModule; typ, origType: PType, name: Rope; info: TLineInfo) =
  genTypeInfoAuxBase(m, typ, typ, name, rope("0"), info)
  var expr = getNimNode(m)
-  if not typ.isEmptyTupleType:
-    var tmp = getTempName(m) & "_" & $typ.kidsLen
-    genTNimNodeArray(m, tmp, rope(typ.kidsLen))
-    for i, a in typ.ikids:
+  if typ.len > 0:
+    var tmp = getTempName(m) & "_" & $typ.len
+    genTNimNodeArray(m, tmp, rope(typ.len))
+    for i in 0..<typ.len:
+      var a = typ[i]
      var tmp2 = getNimNode(m)
      m.s[cfsTypeInit3].addf("$1[$2] = &$3;$n", [tmp, rope(i), tmp2])
      m.s[cfsTypeInit3].addf("$1.kind = 1;$n" &
@@ -1431,10 +1475,10 @@ proc genTupleInfo(m: BModule; typ, origType: PType, name: Rope; info: TLineInfo)
          "$1.name = \"Field$3\";$n",
           [tmp2, getTypeDesc(m, origType, dkVar), rope(i), genTypeInfoV1(m, a, info)])
    m.s[cfsTypeInit3].addf("$1.len = $2; $1.kind = 2; $1.sons = &$3[0];$n",
-         [expr, rope(typ.kidsLen), tmp])
+         [expr, rope(typ.len), tmp])
  else:
    m.s[cfsTypeInit3].addf("$1.len = $2; $1.kind = 2;$n",
-         [expr, rope(typ.kidsLen)])
+         [expr, rope(typ.len)])
  m.s[cfsTypeInit3].addf("$1.node = &$2;$n", [tiNameForHcr(m, name), expr])

 proc genEnumInfo(m: BModule; typ: PType, name: Rope; info: TLineInfo) =
@@ -1479,14 +1523,14 @@ proc genEnumInfo(m: BModule; typ: PType, name: Rope; info: TLineInfo) =
    m.s[cfsTypeInit3].addf("$1.flags = 1<<2;$n", [tiNameForHcr(m, name)])

 proc genSetInfo(m: BModule; typ: PType, name: Rope; info: TLineInfo) =
-  assert(typ.elementType != nil)
+  assert(typ[0] != nil)
  genTypeInfoAux(m, typ, typ, name, info)
  var tmp = getNimNode(m)
  m.s[cfsTypeInit3].addf("$1.len = $2; $1.kind = 0;$n$3.node = &$1;$n",
       [tmp, rope(firstOrd(m.config, typ)), tiNameForHcr(m, name)])

 proc genArrayInfo(m: BModule; typ: PType, name: Rope; info: TLineInfo) =
-  genTypeInfoAuxBase(m, typ, typ, name, genTypeInfoV1(m, typ.elementType, info), info)
+  genTypeInfoAuxBase(m, typ, typ, name, genTypeInfoV1(m, typ[1], info), info)

 proc fakeClosureType(m: BModule; owner: PSym): PType =
  # we generate the same RTTI as for a tuple[pointer, ref tuple[]]
@@ -1502,7 +1546,7 @@ include ccgtrav
 proc genDeepCopyProc(m: BModule; s: PSym; result: Rope) =
  genProc(m, s)
  m.s[cfsTypeInit3].addf("$1.deepcopy =(void* (N_RAW_NIMCALL*)(void*))$2;$n",
-     [result, s.loc.snippet])
+     [result, s.loc.r])

 proc declareNimType(m: BModule; name: string; str: Rope, module: int) =
  let nr = rope(name)
@@ -1555,14 +1599,14 @@ proc generateRttiDestructor(g: ModuleGraph; typ: PType; owner: PSym; kind: TType
  n[paramsPos] = result.typ.n
  let body = newNodeI(nkStmtList, info)
  let castType = makePtrType(typ, idgen)
-  if theProc.typ.firstParamType.kind != tyVar:
+  if theProc.typ[1].kind != tyVar:
    body.add newTreeI(nkCall, info, newSymNode(theProc), newDeref(newTreeIT(
      nkCast, info, castType, newNodeIT(nkType, info, castType),
      newSymNode(dest)
    ))
    )
  else:
-    let addrOf = newNodeIT(nkHiddenAddr, info, theProc.typ.firstParamType)
+    let addrOf = newNodeIT(nkAddr, info, theProc.typ[1])
    addrOf.add newDeref(newTreeIT(
      nkCast, info, castType, newNodeIT(nkType, info, castType),
      newSymNode(dest)
@@ -1590,10 +1634,10 @@ proc genHook(m: BModule; t: PType; info: TLineInfo; op: TTypeAttachedOp; result:
      let wrapper = generateRttiDestructor(m.g.graph, t, theProc.owner, attachedDestructor,
                theProc.info, m.idgen, theProc)
      genProc(m, wrapper)
-      result.add wrapper.loc.snippet
+      result.add wrapper.loc.r
    else:
      genProc(m, theProc)
-      result.add theProc.loc.snippet
+      result.add theProc.loc.r

    when false:
      if not canFormAcycle(m.g.graph, t) and op == attachedTrace:
@@ -1641,7 +1685,7 @@ proc genVTable(seqs: seq[PSym]): string =
  result = "{"
  for i in 0..<seqs.len:
    if i > 0: result.add ", "
-    result.add "(void *) " & seqs[i].loc.snippet
+    result.add "(void *) " & seqs[i].loc.r
  result.add "}"

 proc genTypeInfoV2OldImpl(m: BModule; t, origType: PType, name: Rope; info: TLineInfo) =
@@ -1690,7 +1734,7 @@ proc genTypeInfoV2OldImpl(m: BModule; t, origType: PType, name: Rope; info: TLin

  m.s[cfsTypeInit3].add typeEntry

-  if t.kind == tyObject and t.baseClass != nil and optEnableDeepCopy in m.config.globalOptions:
+  if t.kind == tyObject and t.len > 0 and t[0] != nil and optEnableDeepCopy in m.config.globalOptions:
    discard genTypeInfoV1(m, t, info)

 proc genTypeInfoV2Impl(m: BModule; t, origType: PType, name: Rope; info: TLineInfo) =
@@ -1740,7 +1784,7 @@ proc genTypeInfoV2Impl(m: BModule; t, origType: PType, name: Rope; info: TLineIn
    addf(typeEntry, ", .flags = $1};$n", [rope(flags)])
    m.s[cfsVars].add typeEntry

-  if t.kind == tyObject and t.baseClass != nil and optEnableDeepCopy in m.config.globalOptions:
+  if t.kind == tyObject and t.len > 0 and t[0] != nil and optEnableDeepCopy in m.config.globalOptions:
    discard genTypeInfoV1(m, t, info)

 proc genTypeInfoV2(m: BModule; t: PType; info: TLineInfo): Rope =
@@ -1786,7 +1830,7 @@ proc openArrayToTuple(m: BModule; t: PType): PType =
  result = newType(tyTuple, m.idgen, t.owner)
  let p = newType(tyPtr, m.idgen, t.owner)
  let a = newType(tyUncheckedArray, m.idgen, t.owner)
-  a.add t.elementType
+  a.add t.lastSon
  p.add a
  result.add p
  result.add getSysType(m.g.graph, t.owner.info, tyInt)
@@ -1796,7 +1840,8 @@ proc typeToC(t: PType): string =
  ## to be unique.
  let s = typeToString(t)
  result = newStringOfCap(s.len)
-  for c in s:
+  for i in 0..<s.len:
+    let c = s[i]
    case c
    of 'a'..'z':
      result.add c
@@ -1867,11 +1912,11 @@ proc genTypeInfoV1(m: BModule; t: PType; info: TLineInfo): Rope =
  of tyPointer, tyBool, tyChar, tyCstring, tyString, tyInt..tyUInt64, tyVar, tyLent:
    genTypeInfoAuxBase(m, t, t, result, rope"0", info)
  of tyStatic:
-    if t.n != nil: result = genTypeInfoV1(m, skipModifier t, info)
+    if t.n != nil: result = genTypeInfoV1(m, lastSon t, info)
    else: internalError(m.config, "genTypeInfoV1(" & $t.kind & ')')
  of tyUserTypeClasses:
    internalAssert m.config, t.isResolvedUserTypeClass
-    return genTypeInfoV1(m, t.skipModifier, info)
+    return genTypeInfoV1(m, t.lastSon, info)
  of tyProc:
    if t.callConv != ccClosure:
      genTypeInfoAuxBase(m, t, t, result, rope"0", info)
@@ -1930,11 +1975,8 @@ proc genTypeSection(m: BModule, n: PNode) =
    if len(n[i]) == 0: continue
    if n[i][0].kind != nkPragmaExpr: continue
    for p in 0..<n[i][0].len:
-      if (n[i][0][p].kind notin {nkSym, nkPostfix}): continue
-      var s = n[i][0][p]
-      if s.kind == nkPostfix:
-        s = n[i][0][p][1]
-      if {sfExportc, sfCompilerProc} * s.sym.flags == {sfExportc}:
-        discard getTypeDescAux(m, s.typ, intSet, descKindFromSymKind(s.sym.kind))
+      if (n[i][0][p].kind != nkSym): continue
+      if sfExportc in n[i][0][p].sym.flags:
+        discard getTypeDescAux(m, n[i][0][p].typ, intSet, descKindFromSymKind(n[i][0][p].sym.kind))
        if m.g.generatedHeader != nil:
-          discard getTypeDescAux(m.g.generatedHeader, s.typ, intSet, descKindFromSymKind(s.sym.kind))
+          discard getTypeDescAux(m.g.generatedHeader, n[i][0][p].typ, intSet, descKindFromSymKind(n[i][0][p].sym.kind))
--- a/compiler/ccgutils.nim
+++ b/compiler/ccgutils.nim
@@ -11,9 +11,9 @@

 import
  ast, types, msgs, wordrecg,
-  platform, trees, options, cgendata, mangleutils, renderer
+  platform, trees, options, cgendata

-import std/[hashes, strutils, formatfloat]
+import std/[hashes, strutils]

 when defined(nimPreviewSlimSystem):
  import std/assertions
@@ -68,6 +68,53 @@ proc makeSingleLineCString*(s: string): string =
    c.toCChar(result)
  result.add('\"')

+proc mangle*(name: string): string =
+  result = newStringOfCap(name.len)
+  var start = 0
+  if name[0] in Digits:
+    result.add("X" & name[0])
+    start = 1
+  var requiresUnderscore = false
+  template special(x) =
+    result.add x
+    requiresUnderscore = true
+  for i in start..<name.len:
+    let c = name[i]
+    case c
+    of 'a'..'z', '0'..'9', 'A'..'Z':
+      result.add(c)
+    of '_':
+      # we generate names like 'foo_9' for scope disambiguations and so
+      # disallow this here:
+      if i > 0 and i < name.len-1 and name[i+1] in Digits:
+        discard
+      else:
+        result.add(c)
+    of '$': special "dollar"
+    of '%': special "percent"
+    of '&': special "amp"
+    of '^': special "roof"
+    of '!': special "emark"
+    of '?': special "qmark"
+    of '*': special "star"
+    of '+': special "plus"
+    of '-': special "minus"
+    of '/': special "slash"
+    of '\\': special "backslash"
+    of '=': special "eq"
+    of '<': special "lt"
+    of '>': special "gt"
+    of '~': special "tilde"
+    of ':': special "colon"
+    of '.': special "dot"
+    of '@': special "at"
+    of '|': special "bar"
+    else:
+      result.add("X" & toHex(ord(c), 2))
+      requiresUnderscore = true
+  if requiresUnderscore:
+    result.add "_"
+
 proc mapSetType(conf: ConfigRef; typ: PType): TCTypeKind =
  case int(getSize(conf, typ))
  of 1: result = ctInt8
@@ -79,10 +126,10 @@ proc mapSetType(conf: ConfigRef; typ: PType): TCTypeKind =
 proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
  var pt = skipTypes(s.typ, typedescInst)
  assert skResult != s.kind
-
+  
  #note precedence: params override types
  if optByRef in s.options: return true
-  elif sfByCopy in s.flags: return false
+  elif sfByCopy in s.flags: return false 
  elif tfByRef in pt.flags: return true
  elif tfByCopy in pt.flags: return false
  case pt.kind
@@ -90,9 +137,6 @@ proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
    if s.typ.sym != nil and sfForward in s.typ.sym.flags:
      # forwarded objects are *always* passed by pointers for consistency!
      result = true
-    elif s.typ.kind == tySink and conf.selectedGC notin {gcArc, gcAtomicArc, gcOrc, gcHooks}:
-      # bug #23354:
-      result = false
    elif (optByRef in s.options) or (getSize(conf, pt) > conf.target.floatSize * 3):
      result = true           # requested anyway
    elif (tfFinal in pt.flags) and (pt[0] == nil):
@@ -109,67 +153,3 @@ proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
    result = not (pt.kind in {tyVar, tyArray, tyOpenArray, tyVarargs, tyRef, tyPtr, tyPointer} or
      pt.kind == tySet and mapSetType(conf, pt) == ctArray)

-proc encodeName*(name: string): string =
-  result = mangle(name)
-  result = $result.len & result
-
-proc makeUnique(m: BModule; s: PSym, name: string = ""): string =
-  result = if name == "": s.name.s else: name
-  result.add "__"
-  result.add m.g.graph.ifaces[s.itemId.module].uniqueName
-  result.add "_u"
-  result.add $s.itemId.item
-
-proc encodeSym*(m: BModule; s: PSym; makeUnique: bool = false; extra: string = ""): string =
-  #Module::Type
-  var name = s.name.s & extra
-  if makeUnique:
-    name = makeUnique(m, s, name)
-  "N" & encodeName(s.skipGenericOwner.name.s) & encodeName(name) & "E"
-
-proc encodeType*(m: BModule; t: PType; staticLists: var string): string =
-  result = ""
-  var kindName = ($t.kind)[2..^1]
-  kindName[0] = toLower($kindName[0])[0]
-  case t.kind
-  of tyObject, tyEnum, tyDistinct, tyUserTypeClass, tyGenericParam:
-    result = encodeSym(m, t.sym)
-  of tyGenericInst, tyUserTypeClassInst, tyGenericBody:
-    result = encodeName(t[0].sym.name.s)
-    result.add "I"
-    for i in 1..<t.len - 1:
-      result.add encodeType(m, t[i], staticLists)
-    result.add "E"
-  of tySequence, tyOpenArray, tyArray, tyVarargs, tyTuple, tyProc, tySet, tyTypeDesc,
-    tyPtr, tyRef, tyVar, tyLent, tySink, tyUncheckedArray, tyOr, tyAnd, tyBuiltInTypeClass:
-    result =
-      case t.kind:
-      of tySequence: encodeName("seq")
-      else: encodeName(kindName)
-    result.add "I"
-    for i in 0..<t.len:
-      let s = t[i]
-      if s.isNil: continue
-      result.add encodeType(m, s, staticLists)
-    result.add "E"
-  of tyStatic:
-    if t.n != nil:
-      staticLists.add "_s" & renderTree(t.n)
-    else:
-      raiseAssert "unreachable"
-  of tyRange:
-    var val = "range_"
-    if t.n[0].typ.kind in {tyFloat..tyFloat128}:
-      val.addFloat t.n[0].floatVal
-      val.add "_"
-      val.addFloat t.n[1].floatVal
-    else:
-      val.add $t.n[0].intVal & "_" & $t.n[1].intVal
-    result = encodeName(val)
-  of tyString..tyUInt64, tyPointer, tyBool, tyChar, tyVoid, tyAnything, tyNil, tyEmpty:
-    result = encodeName(kindName)
-  of tyAlias, tyInferred, tyOwned:
-    result = encodeType(m, t.elementType, staticLists)
-  else:
-    assert false, "encodeType " & $t.kind
-
--- a/compiler/cgen.nim
+++ b/compiler/cgen.nim
@@ -14,9 +14,8 @@ import
  nversion, nimsets, msgs, bitsets, idents, types,
  ccgutils, ropes, wordrecg, treetab, cgmeth,
  rodutils, renderer, cgendata, aliases,
-  lowerings, lineinfos, pathutils, transf,
-  injectdestructors, astmsgs, modulepaths, pushpoppragmas,
-  mangleutils
+  lowerings, ndi, lineinfos, pathutils, transf,
+  injectdestructors, astmsgs, modulepaths, backendpragmas

 from expanddefaults import caseObjDefaultBranch

@@ -33,12 +32,6 @@ import std/strutils except `%`, addf # collides with ropes.`%`
 from ic / ic import ModuleBackendFlag
 import std/[dynlib, math, tables, sets, os, intsets, hashes]

-const
-  # we use some ASCII control characters to insert directives that will be converted to real code in a postprocessing pass
-  postprocessDirStart = '\1'
-  postprocessDirSep = '\31'
-  postprocessDirEnd = '\23'
-
 when not declared(dynlib.libCandidates):
  proc libCandidates(s: string, dest: var seq[string]) =
    ## given a library name pattern `s` write possible library names to `dest`.
@@ -72,7 +65,8 @@ proc findPendingModule(m: BModule, s: PSym): BModule =

 proc initLoc(k: TLocKind, lode: PNode, s: TStorageLoc, flags: TLocFlags = {}): TLoc =
  result = TLoc(k: k, storage: s, lode: lode,
-                snippet: "", flags: flags)
+               r: "", flags: flags
+  )

 proc fillLoc(a: var TLoc, k: TLocKind, lode: PNode, r: Rope, s: TStorageLoc) {.inline.} =
  # fills the loc if it is not already initialized
@@ -80,7 +74,7 @@ proc fillLoc(a: var TLoc, k: TLocKind, lode: PNode, r: Rope, s: TStorageLoc) {.i
    a.k = k
    a.lode = lode
    a.storage = s
-    if a.snippet == "": a.snippet = r
+    if a.r == "": a.r = r

 proc fillLoc(a: var TLoc, k: TLocKind, lode: PNode, s: TStorageLoc) {.inline.} =
  # fills the loc if it is not already initialized
@@ -97,7 +91,7 @@ proc t(a: TLoc): PType {.inline.} =

 proc lodeTyp(t: PType): PNode =
  result = newNode(nkEmpty)
-  result.typ() = t
+  result.typ = t

 proc isSimpleConst(typ: PType): bool =
  let t = skipTypes(typ, abstractVar)
@@ -272,28 +266,24 @@ proc safeLineNm(info: TLineInfo): int =
  result = toLinenumber(info)
  if result < 0: result = 0 # negative numbers are not allowed in #line

-proc genPostprocessDir(field1, field2, field3: string): string =
-  result = postprocessDirStart & field1 & postprocessDirSep & field2 & postprocessDirSep & field3 & postprocessDirEnd
-
-proc genCLineDir(r: var Rope, fileIdx: FileIndex, line: int; conf: ConfigRef) =
+proc genCLineDir(r: var Rope, filename: string, line: int; conf: ConfigRef) =
  assert line >= 0
  if optLineDir in conf.options and line > 0:
-    if fileIdx == InvalidFileIdx:
-      r.add(rope("\n#line " & $line & " \"generated_not_to_break_here\"\n"))
-    else:
-      r.add(rope("\n#line " & $line & " FX_" & $fileIdx.int32 & "\n"))
+    r.addf("\n#line $2 $1\n",
+        [rope(makeSingleLineCString(filename)), rope(line)])

-proc genCLineDir(r: var Rope, fileIdx: FileIndex, line: int; p: BProc; info: TLineInfo; lastFileIndex: FileIndex) =
+proc genCLineDir(r: var Rope, filename: string, line: int; p: BProc; info: TLineInfo; lastFileIndex: FileIndex) =
  assert line >= 0
  if optLineDir in p.config.options and line > 0:
-    if fileIdx == InvalidFileIdx:
-      r.add(rope("\n#line " & $line & " \"generated_not_to_break_here\"\n"))
+    if lastFileIndex == info.fileIndex:
+        r.addf("\n#line $1\n", [rope(line)])
    else:
-      r.add(rope("\n#line " & $line & " FX_" & $fileIdx.int32 & "\n"))
+      r.addf("\n#line $2 $1\n",
+        [rope(makeSingleLineCString(filename)), rope(line)])

 proc genCLineDir(r: var Rope, info: TLineInfo; conf: ConfigRef) =
  if optLineDir in conf.options:
-    genCLineDir(r, info.fileIndex, info.safeLineNm, conf)
+    genCLineDir(r, toFullPath(conf, info), info.safeLineNm, conf)

 proc freshLineInfo(p: BProc; info: TLineInfo): bool =
  if p.lastLineInfo.line != info.line or
@@ -308,7 +298,7 @@ proc genCLineDir(r: var Rope, p: BProc, info: TLineInfo; conf: ConfigRef) =
  if optLineDir in conf.options:
    let lastFileIndex = p.lastLineInfo.fileIndex
    if freshLineInfo(p, info):
-      genCLineDir(r, info.fileIndex, info.safeLineNm, p, info, lastFileIndex)
+      genCLineDir(r, toFullPath(conf, info), info.safeLineNm, p, info, lastFileIndex)

 proc genLineDir(p: BProc, t: PNode) =
  if p == p.module.preInitProc: return
@@ -319,11 +309,16 @@ proc genLineDir(p: BProc, t: PNode) =
  let lastFileIndex = p.lastLineInfo.fileIndex
  let freshLine = freshLineInfo(p, t.info)
  if freshLine:
-    genCLineDir(p.s(cpsStmts), t.info.fileIndex, line, p, t.info, lastFileIndex)
+    genCLineDir(p.s(cpsStmts), toFullPath(p.config, t.info), line, p, t.info, lastFileIndex)
  if ({optLineTrace, optStackTrace} * p.options == {optLineTrace, optStackTrace}) and
      (p.prc == nil or sfPure notin p.prc.flags) and t.info.fileIndex != InvalidFileIdx:
      if freshLine:
-        line(p, cpsStmts, genPostprocessDir("nimln", $line, $t.info.fileIndex.int32))
+        if lastFileIndex == t.info.fileIndex:
+          linefmt(p, cpsStmts, "nimln_($1);",
+              [line])
+        else:
+          linefmt(p, cpsStmts, "nimlf_($1, $2);",
+              [line, quotedFilename(p.config, t.info)])

 proc accessThreadLocalVar(p: BProc, s: PSym)
 proc emulatedThreadVars(conf: ConfigRef): bool {.inline.}
@@ -340,22 +335,25 @@ proc getTempName(m: BModule): Rope =
 proc rdLoc(a: TLoc): Rope =
  # 'read' location (deref if indirect)
  if lfIndirect in a.flags:
-    result = "(*" & a.snippet & ")"
+    result = "(*" & a.r & ")"
  else:
-    result = a.snippet
+    result = a.r

 proc addRdLoc(a: TLoc; result: var Rope) =
  if lfIndirect in a.flags:
-    result.add "(*" & a.snippet & ")"
+    result.add "(*" & a.r & ")"
  else:
-    result.add a.snippet
+    result.add a.r

 proc lenField(p: BProc): Rope {.inline.} =
  result = rope(if p.module.compileToCpp: "len" else: "Sup.len")

-proc lenExpr(p: BProc; a: TLoc): Rope =
+proc lenExpr(p: BProc; a: TLoc; isString = false): Rope =
  if optSeqDestructors in p.config.globalOptions:
-    result = rdLoc(a) & ".len"
+    if isString and p.config.isDefined("nimSeqsV3"):
+      result = ropecg(p.module, "(#nimStrLenV3($1))", [rdLoc(a)])
+    else:
+      result = rdLoc(a) & ".len"
  else:
    result = "($1 ? $1->$2 : 0)" % [rdLoc(a), lenField(p)]

@@ -365,15 +363,18 @@ proc dataFieldAccessor(p: BProc, sym: Rope): Rope =
  else:
    result = sym

-proc dataField(p: BProc): Rope =
+proc dataField(p: BProc; isString: bool = false): Rope =
+  # TODO: revisit this after unify strings and seqs
  if optSeqDestructors in p.config.globalOptions:
-    result = rope".p->data"
+    if isString and p.config.isDefined("nimSeqsV3"):
+      result = rope".p"
+    else:
+      result = rope".p->data"
  else:
    result = rope"->data"

 proc genProcPrototype(m: BModule, sym: PSym)

-include cbuilder
 include ccgliterals
 include ccgtypes

@@ -386,22 +387,22 @@ template mapTypeChooser(a: TLoc): TSymKind = mapTypeChooser(a.lode)

 proc addAddrLoc(conf: ConfigRef; a: TLoc; result: var Rope) =
  if lfIndirect notin a.flags and mapType(conf, a.t, mapTypeChooser(a) == skParam) != ctArray:
-    result.add "(&" & a.snippet & ")"
+    result.add "(&" & a.r & ")"
  else:
-    result.add a.snippet
+    result.add a.r

 proc addrLoc(conf: ConfigRef; a: TLoc): Rope =
  if lfIndirect notin a.flags and mapType(conf, a.t, mapTypeChooser(a) == skParam) != ctArray:
-    result = "(&" & a.snippet & ")"
+    result = "(&" & a.r & ")"
  else:
-    result = a.snippet
+    result = a.r

 proc byRefLoc(p: BProc; a: TLoc): Rope =
  if lfIndirect notin a.flags and mapType(p.config, a.t, mapTypeChooser(a) == skParam) != ctArray and not
      p.module.compileToCpp:
-    result = "(&" & a.snippet & ")"
+    result = "(&" & a.r & ")"
  else:
-    result = a.snippet
+    result = a.r

 proc rdCharLoc(a: TLoc): Rope =
  # read a location that may need a char-cast:
@@ -412,9 +413,6 @@ proc rdCharLoc(a: TLoc): Rope =
 type
  TAssignmentFlag = enum
    needToCopy
-    needToCopySinkParam
-    needTempForOpenArray
-    needAssignCall
  TAssignmentFlags = set[TAssignmentFlag]

 proc genObjConstr(p: BProc, e: PNode, d: var TLoc)
@@ -483,22 +481,25 @@ include ccgreset
 proc resetLoc(p: BProc, loc: var TLoc) =
  let containsGcRef = optSeqDestructors notin p.config.globalOptions and containsGarbageCollectedRef(loc.t)
  let typ = skipTypes(loc.t, abstractVarRange)
-  if isImportedCppType(typ): 
-    var didGenTemp = false
-    linefmt(p, cpsStmts, "$1 = $2;$n", [rdLoc(loc), genCppInitializer(p.module, p, typ, didGenTemp)])
-    return
+  if isImportedCppType(typ): return
  if optSeqDestructors in p.config.globalOptions and typ.kind in {tyString, tySequence}:
-    assert loc.snippet != ""
+    assert loc.r != ""

    let atyp = skipTypes(loc.t, abstractInst)
-    if atyp.kind in {tyVar, tyLent}:
-      linefmt(p, cpsStmts, "$1->len = 0; $1->p = NIM_NIL;$n", [rdLoc(loc)])
+    if p.config.isDefined("nimSeqsV3") and typ.kind == tyString:
+      if atyp.kind in {tyVar, tyLent}:
+        linefmt(p, cpsStmts, "$1->rawlen = 0; $1->p = NIM_NIL;$n", [rdLoc(loc)])
+      else:
+        linefmt(p, cpsStmts, "$1.rawlen = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
    else:
-      linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
+      if atyp.kind in {tyVar, tyLent}:
+        linefmt(p, cpsStmts, "$1->len = 0; $1->p = NIM_NIL;$n", [rdLoc(loc)])
+      else:
+        linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
  elif not isComplexValueType(typ):
    if containsGcRef:
      var nilLoc: TLoc = initLoc(locTemp, loc.lode, OnStack)
-      nilLoc.snippet = rope("NIM_NIL")
+      nilLoc.r = rope("NIM_NIL")
      genRefAssign(p, loc, nilLoc)
    else:
      linefmt(p, cpsStmts, "$1 = 0;$n", [rdLoc(loc)])
@@ -531,18 +532,22 @@ proc resetLoc(p: BProc, loc: var TLoc) =

 proc constructLoc(p: BProc, loc: var TLoc, isTemp = false) =
  let typ = loc.t
-  if optSeqDestructors in p.config.globalOptions and skipTypes(typ, abstractInst + {tyStatic}).kind in {tyString, tySequence}:
-    linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
+  let typKind = skipTypes(typ, abstractInst + {tyStatic}).kind
+  if optSeqDestructors in p.config.globalOptions and typKind in {tyString, tySequence}:
+    if typKind == tyString and p.config.isDefined("nimSeqsV3"):
+      linefmt(p, cpsStmts, "$1.rawlen = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
+    else:
+      linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
  elif not isComplexValueType(typ):
    if containsGarbageCollectedRef(loc.t):
      var nilLoc: TLoc = initLoc(locTemp, loc.lode, OnStack)
-      nilLoc.snippet = rope("NIM_NIL")
+      nilLoc.r = rope("NIM_NIL")
      genRefAssign(p, loc, nilLoc)
    else:
      linefmt(p, cpsStmts, "$1 = ($2)0;$n", [rdLoc(loc),
        getTypeDesc(p.module, typ, descKindFromSymKind mapTypeChooser(loc))])
  else:
-    if (not isTemp or containsGarbageCollectedRef(loc.t)) and not hasNoInit(loc.t):
+    if not isTemp or containsGarbageCollectedRef(loc.t):
      # don't use nimZeroMem for temporary values for performance if we can
      # avoid it:
      if not isOrHasImportedCppType(typ):
@@ -564,14 +569,13 @@ proc initLocalVar(p: BProc, v: PSym, immediateAsgn: bool) =

 proc getTemp(p: BProc, t: PType, needsInit=false): TLoc =
  inc(p.labels)
-  result = TLoc(snippet: "T" & rope(p.labels) & "_", k: locTemp, lode: lodeTyp t,
+  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp, lode: lodeTyp t,
                storage: OnStack, flags: {})
  if p.module.compileToCpp and isOrHasImportedCppType(t):
-    var didGenTemp = false
-    linefmt(p, cpsLocals, "$1 $2$3;$n", [getTypeDesc(p.module, t, dkVar), result.snippet,
-      genCppInitializer(p.module, p, t, didGenTemp)])
+    linefmt(p, cpsLocals, "$1 $2$3;$n", [getTypeDesc(p.module, t, dkVar), result.r,
+      genCppInitializer(p.module, p, t)])
  else:
-    linefmt(p, cpsLocals, "$1 $2;$n", [getTypeDesc(p.module, t, dkVar), result.snippet])
+    linefmt(p, cpsLocals, "$1 $2;$n", [getTypeDesc(p.module, t, dkVar), result.r])
  constructLoc(p, result, not needsInit)
  when false:
    # XXX Introduce a compiler switch in order to detect these easily.
@@ -584,16 +588,16 @@ proc getTemp(p: BProc, t: PType, needsInit=false): TLoc =

 proc getTempCpp(p: BProc, t: PType, value: Rope): TLoc =
  inc(p.labels)
-  result = TLoc(snippet: "T" & rope(p.labels) & "_", k: locTemp, lode: lodeTyp t,
+  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp, lode: lodeTyp t,
                storage: OnStack, flags: {})
-  linefmt(p, cpsStmts, "auto $1 = $2;$n", [result.snippet, value])
+  linefmt(p, cpsStmts, "$1 $2 = $3;$n", [getTypeDesc(p.module, t, dkVar), result.r, value])

 proc getIntTemp(p: BProc): TLoc =
  inc(p.labels)
-  result = TLoc(snippet: "T" & rope(p.labels) & "_", k: locTemp,
+  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp,
                storage: OnStack, lode: lodeTyp getSysType(p.module.g.graph, unknownLineInfo, tyInt),
                flags: {})
-  linefmt(p, cpsLocals, "NI $1;$n", [result.snippet])
+  linefmt(p, cpsLocals, "NI $1;$n", [result.r])

 proc localVarDecl(p: BProc; n: PNode): Rope =
  result = ""
@@ -615,9 +619,9 @@ proc localVarDecl(p: BProc; n: PNode): Rope =
    if sfVolatile in s.flags: result.add(" volatile")
    if sfNoalias in s.flags: result.add(" NIM_NOALIAS")
    result.add(" ")
-    result.add(s.loc.snippet)
+    result.add(s.loc.r)
  else:
-    result = runtimeFormat(s.cgDeclFrmt, [result, s.loc.snippet])
+    result = runtimeFormat(s.cgDeclFrmt, [result, s.loc.r])

 proc assignLocalVar(p: BProc, n: PNode) =
  #assert(s.loc.k == locNone) # not yet assigned
@@ -626,8 +630,7 @@ proc assignLocalVar(p: BProc, n: PNode) =
  let nl = if optLineDir in p.config.options: "" else: "\n"
  var decl = localVarDecl(p, n)
  if p.module.compileToCpp and isOrHasImportedCppType(n.typ):
-    var didGenTemp = false
-    decl.add genCppInitializer(p.module, p, n.typ, didGenTemp)
+    decl.add genCppInitializer(p.module, p, n.typ)
  decl.add ";" & nl
  line(p, cpsLocals, decl)

@@ -658,11 +661,22 @@ proc genGlobalVarDecl(p: BProc, n: PNode; td, value: Rope; decl: var Rope) =
    if sfNoalias in s.flags: decl.add(" NIM_NOALIAS")
  else:
    if value != "":
-      decl = runtimeFormat(s.cgDeclFrmt & " = $#;$n", [td, s.loc.snippet, value])
+      decl = runtimeFormat(s.cgDeclFrmt & " = $#;$n", [td, s.loc.r, value])
    else:
-      decl = runtimeFormat(s.cgDeclFrmt & ";$n", [td, s.loc.snippet])
+      decl = runtimeFormat(s.cgDeclFrmt & ";$n", [td, s.loc.r])

-proc genCppVarForCtor(p: BProc; call: PNode; decl: var Rope; didGenTemp: var bool)
+proc genCppVarForCtor(p: BProc; call: PNode; decl: var Rope)
+
+proc callGlobalVarCppCtor(p: BProc; v: PSym; vn, value: PNode) =
+  let s = vn.sym
+  fillBackendName(p.module, s)
+  fillLoc(s.loc, locGlobalVar, vn, OnHeap)
+  var decl: Rope = ""
+  let td = getTypeDesc(p.module, vn.sym.typ, dkVar)
+  genGlobalVarDecl(p, vn, td, "", decl)
+  decl.add " " & $s.loc.r
+  genCppVarForCtor(p, value, decl)
+  p.module.s[cfsVars].add decl

 proc assignGlobalVar(p: BProc, n: PNode; value: Rope) =
  let s = n.sym
@@ -676,7 +690,7 @@ proc assignGlobalVar(p: BProc, n: PNode; value: Rope) =
    if q != nil and not containsOrIncl(q.declaredThings, s.id):
      varInDynamicLib(q, s)
    else:
-      s.loc.snippet = mangleDynLibProc(s)
+      s.loc.r = mangleDynLibProc(s)
    if value != "":
      internalError(p.config, n.info, ".dynlib variables cannot have a value")
    return
@@ -707,31 +721,19 @@ proc assignGlobalVar(p: BProc, n: PNode; value: Rope) =
            # [^0]: https://en.cppreference.com/w/cpp/language/aggregate_initialization
            # [^1]: https://cplusplus.github.io/CWG/issues/1518.html
            # [^2]: https://eel.is/c++draft/over.match.ctor
-            decl.addf(" $1;$n", [s.loc.snippet])
+            decl.addf(" $1;$n", [s.loc.r])
          else:
-            decl.addf(" $1 = $2;$n", [s.loc.snippet, value])
+            decl.addf(" $1 = $2;$n", [s.loc.r, value])
        else:
-          decl.addf(" $1;$n", [s.loc.snippet])
+          decl.addf(" $1;$n", [s.loc.r])

      p.module.s[cfsVars].add(decl)
  if p.withinLoop > 0 and value == "":
    # fixes tests/run/tzeroarray:
    resetLoc(p, s.loc)

-proc callGlobalVarCppCtor(p: BProc; v: PSym; vn, value: PNode; didGenTemp: var bool) =
-  let s = vn.sym
-  fillBackendName(p.module, s)
-  fillLoc(s.loc, locGlobalVar, vn, OnHeap)
-  var decl: Rope = ""
-  let td = getTypeDesc(p.module, vn.sym.typ, dkVar)
-  genGlobalVarDecl(p, vn, td, "", decl)
-  decl.add " " & $s.loc.snippet
-  genCppVarForCtor(p, value, decl, didGenTemp)
-  if didGenTemp:  return # generated in the caller
-  p.module.s[cfsVars].add decl
-
 proc assignParam(p: BProc, s: PSym, retType: PType) =
-  assert(s.loc.snippet != "")
+  assert(s.loc.r != "")
  scopeMangledParam(p, s)

 proc fillProcLoc(m: BModule; n: PNode) =
@@ -757,7 +759,6 @@ proc intLiteral(i: BiggestInt; result: var Rope)
 proc genLiteral(p: BProc, n: PNode; result: var Rope)
 proc genOtherArg(p: BProc; ri: PNode; i: int; typ: PType; result: var Rope; argsCounter: var int)
 proc raiseExit(p: BProc)
-proc raiseExitCleanup(p: BProc, destroy: string)

 proc initLocExpr(p: BProc, e: PNode, flags: TLocFlags = {}): TLoc =
  result = initLoc(locNone, e, OnUnknown, flags)
@@ -784,11 +785,15 @@ $1define nimfr_(proc, file) \
  TFrame FR_; \
  FR_.procname = proc; FR_.filename = file; FR_.line = 0; FR_.len = 0; #nimFrame(&FR_);

-$1define nimln_(n) \
-  FR_.line = n;
+  $1define nimfrs_(proc, file, slots, length) \
+    struct {TFrame* prev;NCSTRING procname;NI line;NCSTRING filename;NI len;VarSlot s[slots];} FR_; \
+    FR_.procname = proc; FR_.filename = file; FR_.line = 0; FR_.len = length; #nimFrame((TFrame*)&FR_);

-$1define nimlf_(n, file) \
-  FR_.line = n; FR_.filename = file;
+  $1define nimln_(n) \
+    FR_.line = n;
+
+  $1define nimlf_(n, file) \
+    FR_.line = n; FR_.filename = file;

 """
  if p.module.s[cfsFrameDefines].len == 0:
@@ -852,7 +857,7 @@ proc loadDynamicLib(m: BModule, lib: PLib) =
      p.options.excl optStackTrace
      p.flags.incl nimErrorFlagDisabled
      var dest: TLoc = initLoc(locTemp, lib.path, OnStack)
-      dest.snippet = getTempName(m)
+      dest.r = getTempName(m)
      appcg(m, m.s[cfsDynLibInit],"$1 $2;$n",
           [getTypeDesc(m, lib.path.typ, dkVar), rdLoc(dest)])
      expr(p, lib.path, dest)
@@ -870,7 +875,7 @@ proc mangleDynLibProc(sym: PSym): Rope =
  # we have to build this as a single rope in order not to trip the
  # optimization in genInfixCall, see test tests/cpp/t8241.nim
  if sfCompilerProc in sym.flags:
-    # NOTE: sym.loc.snippet is the external name!
+    # NOTE: sym.loc.r is the external name!
    result = rope(sym.name.s)
  else:
    result = rope(strutils.`%`("Dl_$1_", $sym.id))
@@ -878,10 +883,10 @@ proc mangleDynLibProc(sym: PSym): Rope =
 proc symInDynamicLib(m: BModule, sym: PSym) =
  var lib = sym.annex
  let isCall = isGetProcAddr(lib)
-  var extname = sym.loc.snippet
+  var extname = sym.loc.r
  if not isCall: loadDynamicLib(m, lib)
  var tmp = mangleDynLibProc(sym)
-  sym.loc.snippet = tmp             # from now on we only need the internal name
+  sym.loc.r = tmp             # from now on we only need the internal name
  sym.typ.sym = nil           # generate a new name
  inc(m.labels, 2)
  if isCall:
@@ -908,24 +913,24 @@ proc symInDynamicLib(m: BModule, sym: PSym) =
    appcg(m, m.s[cfsDynLibInit],
        "\t$1 = ($2) #nimGetProcAddr($3, $4);$n",
        [tmp, getTypeDesc(m, sym.typ, dkVar), lib.name, makeCString($extname)])
-  m.s[cfsVars].addf("$2 $1;$n", [sym.loc.snippet, getTypeDesc(m, sym.loc.t, dkVar)])
+  m.s[cfsVars].addf("$2 $1;$n", [sym.loc.r, getTypeDesc(m, sym.loc.t, dkVar)])

 proc varInDynamicLib(m: BModule, sym: PSym) =
  var lib = sym.annex
-  var extname = sym.loc.snippet
+  var extname = sym.loc.r
  loadDynamicLib(m, lib)
  incl(sym.loc.flags, lfIndirect)
  var tmp = mangleDynLibProc(sym)
-  sym.loc.snippet = tmp             # from now on we only need the internal name
+  sym.loc.r = tmp             # from now on we only need the internal name
  inc(m.labels, 2)
  appcg(m, m.s[cfsDynLibInit],
      "$1 = ($2*) #nimGetProcAddr($3, $4);$n",
      [tmp, getTypeDesc(m, sym.typ, dkVar), lib.name, makeCString($extname)])
  m.s[cfsVars].addf("$2* $1;$n",
-      [sym.loc.snippet, getTypeDesc(m, sym.loc.t, dkVar)])
+      [sym.loc.r, getTypeDesc(m, sym.loc.t, dkVar)])

 proc symInDynamicLibPartial(m: BModule, sym: PSym) =
-  sym.loc.snippet = mangleDynLibProc(sym)
+  sym.loc.r = mangleDynLibProc(sym)
  sym.typ.sym = nil           # generate a new name

 proc cgsymImpl(m: BModule; sym: PSym) {.inline.} =
@@ -948,7 +953,7 @@ proc cgsymValue(m: BModule, name: string): Rope =
    cgsymImpl m, sym
  else:
    rawMessage(m.config, errGenerated, "system module needs: " & name)
-  result = sym.loc.snippet
+  result = sym.loc.r
  if m.hcrOn and sym != nil and sym.kind in {skProc..skIterator}:
    result.addActualSuffixForHCR(m.module, sym)

@@ -1044,7 +1049,7 @@ proc easyResultAsgn(n: PNode): PNode =
 type
  InitResultEnum = enum Unknown, InitSkippable, InitRequired

-proc allPathsAsgnResult(p: BProc; n: PNode): InitResultEnum =
+proc allPathsAsgnResult(n: PNode): InitResultEnum =
  # Exceptions coming from calls don't have not be considered here:
  #
  # proc bar(): string = raise newException(...)
@@ -1059,7 +1064,7 @@ proc allPathsAsgnResult(p: BProc; n: PNode): InitResultEnum =
  #   echo "a was not written to"
  #
  template allPathsInBranch(it) =
-    let a = allPathsAsgnResult(p, it)
+    let a = allPathsAsgnResult(it)
    case a
    of InitRequired: return InitRequired
    of InitSkippable: discard
@@ -1071,20 +1076,14 @@ proc allPathsAsgnResult(p: BProc; n: PNode): InitResultEnum =
  case n.kind
  of nkStmtList, nkStmtListExpr:
    for it in n:
-      result = allPathsAsgnResult(p, it)
+      result = allPathsAsgnResult(it)
      if result != Unknown: return result
  of nkAsgn, nkFastAsgn, nkSinkAsgn:
    if n[0].kind == nkSym and n[0].sym.kind == skResult:
-      if not containsResult(n[1]):
-        if allPathsAsgnResult(p, n[1]) == InitRequired:
-          result = InitRequired
-        else:
-          result = InitSkippable
+      if not containsResult(n[1]): result = InitSkippable
      else: result = InitRequired
    elif containsResult(n):
      result = InitRequired
-    else:
-      result = allPathsAsgnResult(p, n[1])
  of nkReturnStmt:
    if n.len > 0:
      if n[0].kind == nkEmpty and result != InitSkippable:
@@ -1093,7 +1092,7 @@ proc allPathsAsgnResult(p: BProc; n: PNode): InitResultEnum =
        # initialized. This avoids cases like #9286 where this heuristic lead to
        # wrong code being generated.
        result = InitRequired
-      else: result = allPathsAsgnResult(p, n[0])
+      else: result = allPathsAsgnResult(n[0])
  of nkIfStmt, nkIfExpr:
    var exhaustive = false
    result = InitSkippable
@@ -1119,9 +1118,9 @@ proc allPathsAsgnResult(p: BProc; n: PNode): InitResultEnum =
  of nkWhileStmt:
    # some dubious code can assign the result in the 'while'
    # condition and that would be fine. Everything else isn't:
-    result = allPathsAsgnResult(p, n[0])
+    result = allPathsAsgnResult(n[0])
    if result == Unknown:
-      result = allPathsAsgnResult(p, n[1])
+      result = allPathsAsgnResult(n[1])
      # we cannot assume that the 'while' loop is really executed at least once:
      if result == InitSkippable: result = Unknown
  of harmless:
@@ -1146,21 +1145,9 @@ proc allPathsAsgnResult(p: BProc; n: PNode): InitResultEnum =
    allPathsInBranch(n[0])
    for i in 1..<n.len:
      if n[i].kind == nkFinally:
-        result = allPathsAsgnResult(p, n[i].lastSon)
+        result = allPathsAsgnResult(n[i].lastSon)
      else:
        allPathsInBranch(n[i].lastSon)
-  of nkCallKinds:
-    if canRaiseDisp(p, n[0]):
-      result = InitRequired
-    else:
-      for i in 0..<n.safeLen:
-        allPathsInBranch(n[i])
-  of nkRaiseStmt:
-    result = InitRequired
-  of nkChckRangeF, nkChckRange64, nkChckRange:
-    # TODO: more checks might need to be covered like overflow, indexDefect etc.
-    # bug #22852
-    result = InitRequired
  else:
    for i in 0..<n.safeLen:
      allPathsInBranch(n[i])
@@ -1201,7 +1188,7 @@ proc genProcAux*(m: BModule, prc: PSym) =
  let tmpInfo = prc.info
  discard freshLineInfo(p, prc.info)

-  if sfPure notin prc.flags and prc.typ.returnType != nil:
+  if sfPure notin prc.flags and prc.typ[0] != nil:
    if resultPos >= prc.ast.len:
      internalError(m.config, prc.info, "proc has no result symbol")
    let resNode = prc.ast[resultPos]
@@ -1215,9 +1202,9 @@ proc genProcAux*(m: BModule, prc: PSym) =
      else:
        # declare the result symbol:
        assignLocalVar(p, resNode)
-        assert(res.loc.snippet != "")
+        assert(res.loc.r != "")
        if p.config.selectedGC in {gcArc, gcAtomicArc, gcOrc} and
-            allPathsAsgnResult(p, procBody) == InitSkippable:
+            allPathsAsgnResult(procBody) == InitSkippable:
          # In an ideal world the codegen could rely on injectdestructors doing its job properly
          # and then the analysis step would not be required.
          discard "result init optimized out"
@@ -1227,10 +1214,9 @@ proc genProcAux*(m: BModule, prc: PSym) =
    elif sfConstructor in prc.flags:
      resNode.sym.loc.flags.incl lfIndirect
      fillLoc(resNode.sym.loc, locParam, resNode, "this", OnHeap)
-      prc.loc.snippet = getTypeDesc(m, resNode.sym.loc.t, dkVar)
    else:
      fillResult(p.config, resNode, prc.typ)
-      assignParam(p, res, prc.typ.returnType)
+      assignParam(p, res, prc.typ[0])
      # We simplify 'unsureAsgn(result, nil); unsureAsgn(result, x)'
      # to 'unsureAsgn(result, x)'
      # Sketch why this is correct: If 'result' points to a stack location
@@ -1238,7 +1224,7 @@ proc genProcAux*(m: BModule, prc: PSym) =
      # global is either 'nil' or points to valid memory and so the RC operation
      # succeeds without touching not-initialized memory.
      if sfNoInit in prc.flags: discard
-      elif allPathsAsgnResult(p, procBody) == InitSkippable: discard
+      elif allPathsAsgnResult(procBody) == InitSkippable: discard
      else:
        resetLoc(p, res.loc)
      if skipTypes(res.typ, abstractInst).kind == tyArray:
@@ -1248,7 +1234,7 @@ proc genProcAux*(m: BModule, prc: PSym) =
  for i in 1..<prc.typ.n.len:
    let param = prc.typ.n[i].sym
    if param.typ.isCompileTimeOnly: continue
-    assignParam(p, param, prc.typ.returnType)
+    assignParam(p, param, prc.typ[0])
  closureSetup(p, prc)
  genProcBody(p, procBody)

@@ -1292,7 +1278,7 @@ proc genProcAux*(m: BModule, prc: PSym) =
  m.s[cfsProcs].add(generatedProc)
  if isReloadable(m, prc):
    m.s[cfsDynLibInit].addf("\t$1 = ($3) hcrRegisterProc($4, \"$1\", (void*)$2);$n",
-         [prc.loc.snippet, prc.loc.snippet & "_actual", getProcTypeCast(m, prc), getModuleDllPath(m, prc)])
+         [prc.loc.r, prc.loc.r & "_actual", getProcTypeCast(m, prc), getModuleDllPath(m, prc)])

 proc requiresExternC(m: BModule; sym: PSym): bool {.inline.} =
  result = (sfCompileToCpp in m.module.flags and
@@ -1352,7 +1338,7 @@ proc genProcNoForward(m: BModule, prc: PSym) =
      # the hcr dynlib (also put it in the DynLibInit section - right after it gets loaded)
      if isReloadable(q, prc):
        q.s[cfsDynLibInit].addf("\t$1 = ($2) hcrRegisterProc($3, \"$1\", (void*)$1);$n",
-            [prc.loc.snippet, getTypeDesc(q, prc.loc.t), getModuleDllPath(m, q.module)])
+            [prc.loc.r, getTypeDesc(q, prc.loc.t), getModuleDllPath(m, q.module)])
    else:
      symInDynamicLibPartial(m, prc)
  elif prc.typ.callConv == ccInline:
@@ -1369,8 +1355,8 @@ proc genProcNoForward(m: BModule, prc: PSym) =
      #elif {sfExportc, sfImportc} * prc.flags == {}:
      #  # reset name to restore consistency in case of hashing collisions:
      #  echo "resetting ", prc.id, " by ", m.module.name.s
-      #  prc.loc.snippet = nil
-      #  prc.loc.snippet = mangleName(m, prc)
+      #  prc.loc.r = nil
+      #  prc.loc.r = mangleName(m, prc)
      genProcPrototype(m, prc)
      genProcAux(m, prc)
  elif sfImportc notin prc.flags:
@@ -1382,7 +1368,7 @@ proc genProcNoForward(m: BModule, prc: PSym) =
    if isReloadable(m, prc) and prc.id notin m.declaredProtos and
      q != nil and q.module.id != m.module.id:
      m.s[cfsDynLibInit].addf("\t$1 = ($2) hcrGetProc($3, \"$1\");$n",
-           [prc.loc.snippet, getProcTypeCast(m, prc), getModuleDllPath(m, prc)])
+           [prc.loc.r, getProcTypeCast(m, prc), getModuleDllPath(m, prc)])
    genProcPrototype(m, prc)
    if q != nil and not containsOrIncl(q.declaredThings, prc.id):
      # make sure there is a "prototype" in the external module
@@ -1435,7 +1421,7 @@ proc genVarPrototype(m: BModule, n: PNode) =
    return
  if sym.owner.id != m.module.id:
    # else we already have the symbol generated!
-    assert(sym.loc.snippet != "")
+    assert(sym.loc.r != "")
    incl(m.declaredThings, sym.id)
    if sfThread in sym.flags:
      declareThreadVar(m, sym, true)
@@ -1449,9 +1435,9 @@ proc genVarPrototype(m: BModule, n: PNode) =
      if sfRegister in sym.flags: m.s[cfsVars].add(" register")
      if sfVolatile in sym.flags: m.s[cfsVars].add(" volatile")
      if sfNoalias in sym.flags: m.s[cfsVars].add(" NIM_NOALIAS")
-      m.s[cfsVars].addf(" $1;$n", [sym.loc.snippet])
+      m.s[cfsVars].addf(" $1;$n", [sym.loc.r])
      if m.hcrOn: m.initProc.procSec(cpsLocals).addf(
-        "\t$1 = ($2*)hcrGetGlobal($3, \"$1\");$n", [sym.loc.snippet,
+        "\t$1 = ($2*)hcrGetGlobal($3, \"$1\");$n", [sym.loc.r,
        getTypeDesc(m, sym.loc.t, dkVar), getModuleDllPath(m, sym)])

 proc addNimDefines(result: var Rope; conf: ConfigRef) {.inline.} =
@@ -1484,13 +1470,15 @@ proc getFileHeader(conf: ConfigRef; cfile: Cfile): Rope =

 proc getSomeNameForModule(conf: ConfigRef, filename: AbsoluteFile): Rope =
  ## Returns a mangled module name.
-  result = mangleModuleName(conf, filename).mangle
+  result = ""
+  result.add mangleModuleName(conf, filename).mangle

 proc getSomeNameForModule(m: BModule): Rope =
  ## Returns a mangled module name.
  assert m.module.kind == skModule
  assert m.module.owner.kind == skPackage
-  result = mangleModuleName(m.g.config, m.filename).mangle
+  result = ""
+  result.add mangleModuleName(m.g.config, m.filename).mangle

 proc getSomeInitName(m: BModule, suffix: string): Rope =
  if not m.hcrOn:
@@ -1826,7 +1814,7 @@ proc genDatInitCode(m: BModule) =

  # we don't want to break into such init code - could happen if a line
  # directive from a function written by the user spills after itself
-  genCLineDir(prc, InvalidFileIdx, 999999, m.config)
+  genCLineDir(prc, "generated_not_to_break_here", 999999, m.config)

  for i in cfsTypeInit1..cfsDynLibInit:
    if m.s[i].len != 0:
@@ -1848,11 +1836,11 @@ proc hcrGetProcLoadCode(m: BModule, sym, prefix, handle, getProcFunc: string): R

  var extname = prefix & sym
  var tmp = mangleDynLibProc(prc)
-  prc.loc.snippet = tmp
+  prc.loc.r = tmp
  prc.typ.sym = nil

  if not containsOrIncl(m.declaredThings, prc.id):
-    m.s[cfsVars].addf("static $2 $1;$n", [prc.loc.snippet, getTypeDesc(m, prc.loc.t, dkVar)])
+    m.s[cfsVars].addf("static $2 $1;$n", [prc.loc.r, getTypeDesc(m, prc.loc.t, dkVar)])

  result = "\t$1 = ($2) $3($4, $5);$n" %
      [tmp, getTypeDesc(m, prc.typ, dkVar), getProcFunc.rope, handle.rope, makeCString(prefix & sym)]
@@ -1867,7 +1855,7 @@ proc genInitCode(m: BModule) =
    [rope(if m.hcrOn: "N_LIB_EXPORT" else: "N_LIB_PRIVATE"), initname]
  # we don't want to break into such init code - could happen if a line
  # directive from a function written by the user spills after itself
-  genCLineDir(prc, InvalidFileIdx, 999999, m.config)
+  genCLineDir(prc, "generated_not_to_break_here", 999999, m.config)
  if m.typeNodes > 0:
    if m.hcrOn:
      appcg(m, m.s[cfsTypeInit1], "\t#TNimNode* $1;$N", [m.typeNodesName])
@@ -1937,6 +1925,9 @@ proc genInitCode(m: BModule) =

    if optStackTrace in m.initProc.options and preventStackTrace notin m.flags:
      prc.add(deinitFrame(m.initProc))
+  elif m.config.exc == excGoto:
+    if getCompilerProc(m.g.graph, "nimTestErrorFlag") != nil:
+      m.appcg(prc, "\t#nimTestErrorFlag();$n", [])

  prc.addf("}$N", [])

@@ -1979,40 +1970,6 @@ proc genInitCode(m: BModule) =

  registerModuleToMain(m.g, m)

-proc postprocessCode(conf: ConfigRef, r: var Rope) =
-  # find the first directive
-  var f = r.find(postprocessDirStart)
-  if f == -1:
-    return
-
-  var
-    nimlnDirLastF = ""
-
-  var res: Rope = r.substr(0, f - 1)
-  while f != -1:
-    var
-      e = r.find(postprocessDirEnd, f + 1)
-      dir = r.substr(f + 1, e - 1).split(postprocessDirSep)
-    case dir[0]
-    of "nimln":
-      if dir[2] == nimlnDirLastF:
-        res.add("nimln_(" & dir[1] & ");")
-      else:
-        res.add("nimlf_(" & dir[1] & ", " & quotedFilename(conf, dir[2].parseInt.FileIndex) & ");")
-        nimlnDirLastF = dir[2]
-    else:
-      raiseAssert "unexpected postprocess directive"
-
-    # find the next directive
-    f = r.find(postprocessDirStart, e + 1)
-    # copy the code until the next directive
-    if f != -1:
-      res.add(r.substr(e + 1, f - 1))
-    else:
-      res.add(r.substr(e + 1))
-
-  r = res
-
 proc genModule(m: BModule, cfile: Cfile): Rope =
  var moduleIsEmpty = true

@@ -2041,17 +1998,9 @@ proc genModule(m: BModule, cfile: Cfile): Rope =
  if m.config.cppCustomNamespace.len > 0:
    closeNamespaceNim(result)

-  if optLineDir in m.config.options:
-    var srcFileDefs = ""
-    for fi in 0..m.config.m.fileInfos.high:
-      srcFileDefs.add("#define FX_" & $fi & " " & makeSingleLineCString(toFullPath(m.config, fi.FileIndex)) & "\n")
-    result = srcFileDefs & result
-
  if moduleIsEmpty:
    result = ""

-  postprocessCode(m.config, result)
-
 proc initProcOptions(m: BModule): TOptions =
  let opts = m.config.options
  if sfSystemModule in m.module.flags: opts-{optStackTrace} else: opts
@@ -2085,6 +2034,9 @@ proc rawNewModule(g: BModuleList; module: PSym, filename: AbsoluteFile): BModule
  if sfSystemModule in module.flags:
    incl result.flags, preventStackTrace
    excl(result.preInitProc.options, optStackTrace)
+  let ndiName = if optCDebug in g.config.globalOptions: changeFileExt(completeCfilePath(g.config, filename), "ndi")
+                else: AbsoluteFile""
+  open(result.ndi, ndiName, g.config)

 proc rawNewModule(g: BModuleList; module: PSym; conf: ConfigRef): BModule =
  result = rawNewModule(g, module, AbsoluteFile toFullPath(conf, module.position.FileIndex))
@@ -2214,6 +2166,7 @@ proc shouldRecompile(m: BModule; code: Rope, cfile: Cfile): bool =
 # it would generate multiple 'main' procs, for instance.

 proc writeModule(m: BModule, pending: bool) =
+  template onExit() = close(m.ndi, m.config)
  let cfile = getCFile(m)
  if moduleHasChanged(m.g.graph, m.module):
    genInitCode(m)
@@ -2231,10 +2184,12 @@ proc writeModule(m: BModule, pending: bool) =
    when hasTinyCBackend:
      if m.config.cmd == cmdTcc:
        tccgen.compileCCode($code, m.config)
+        onExit()
        return

    if not shouldRecompile(m, code, cf): cf.flags = {CfileFlag.Cached}
    addFileToCompile(m.config, cf)
+  onExit()

 proc updateCachedModule(m: BModule) =
  let cfile = getCFile(m)
@@ -2245,23 +2200,6 @@ proc updateCachedModule(m: BModule) =
  cf.flags = {CfileFlag.Cached}
  addFileToCompile(m.config, cf)

-proc generateLibraryDestroyGlobals(graph: ModuleGraph; m: BModule; body: PNode; isDynlib: bool): PSym =
-  let prefixedName = m.config.nimMainPrefix & "NimDestroyGlobals"
-  let procname = getIdent(graph.cache, prefixedName)
-  result = newSym(skProc, procname, m.idgen, m.module.owner, m.module.info)
-  result.typ = newProcType(m.module.info, m.idgen, m.module.owner)
-  result.typ.callConv = ccCDecl
-  incl result.flags, sfExportc
-  result.loc.snippet = prefixedName
-  if isDynlib:
-    incl(result.loc.flags, lfExportLib)
-
-  let theProc = newNodeI(nkProcDef, m.module.info, bodyPos+1)
-  for i in 0..<theProc.len: theProc[i] = newNodeI(nkEmpty, m.module.info)
-  theProc[namePos] = newSymNode(result)
-  theProc[bodyPos] = body
-  result.ast = theProc
-
 proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode) =
  ## Also called from IC.
  if sfMainModule in m.module.flags:
@@ -2273,13 +2211,6 @@ proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode) =
    if {optGenStaticLib, optGenDynLib, optNoMain} * m.config.globalOptions == {}:
      for i in countdown(high(graph.globalDestructors), 0):
        n.add graph.globalDestructors[i]
-    else:
-      var body = newNodeI(nkStmtList, m.module.info)
-      for i in countdown(high(graph.globalDestructors), 0):
-        body.add graph.globalDestructors[i]
-      body.flags.incl nfTransf # should not be further transformed
-      let dtor = generateLibraryDestroyGlobals(graph, m, body, optGenDynLib in m.config.globalOptions)
-      genProcAux(m, dtor)
  if pipelineutils.skipCodegen(m.config, n): return
  if moduleHasChanged(graph, m.module):
    # if the module is cached, we don't regenerate the main proc
--- a/compiler/cgendata.nim
+++ b/compiler/cgendata.nim
@@ -11,7 +11,7 @@

 import
  ast, ropes, options,
-  lineinfos, pathutils, modulegraphs
+  ndi, lineinfos, pathutils, modulegraphs

 import std/[intsets, tables, sets]

@@ -88,7 +88,7 @@ type
    options*: TOptions        # options that should be used for code
                              # generation; this is the same as prc.options
                              # unless prc == nil
-    optionsStack*: seq[(TOptions, TNoteKinds)]
+    optionsStack*: seq[TOptions]
    module*: BModule          # used to prevent excessive parameter passing
    withinLoop*: int          # > 0 if we are within a loop
    splitDecls*: int          # > 0 if we are in some context for C++ that
@@ -137,7 +137,6 @@ type
                            # unconditionally...
                            # nimtvDeps is VERY hard to cache because it's
                            # not a list of IDs nor can it be made to be one.
-    mangledPrcs*: HashSet[string]

  TCGen = object of PPassContext # represents a C source file
    s*: TCFileSections        # sections of the C file
@@ -151,7 +150,7 @@ type
    typeABICache*: HashSet[SigHash] # cache for ABI checks; reusing typeCache
                              # would be ideal but for some reason enums
                              # don't seem to get cached so it'd generate
-                              # 1 ABI check per occurrence in code
+                              # 1 ABI check per occurence in code
    forwTypeCache*: TypeCache # cache for forward declarations of types
    declaredThings*: IntSet   # things we have declared in this .c file
    declaredProtos*: IntSet   # prototypes we have declared in this .c file
@@ -172,6 +171,7 @@ type
                                             # OpenGL wrapper
    sigConflicts*: CountTable[SigHash]
    g*: BModuleList
+    ndi*: NdiFile

 template config*(m: BModule): ConfigRef = m.g.config
 template config*(p: BProc): ConfigRef = p.module.g.config
--- a/compiler/cgmeth.nim
+++ b/compiler/cgmeth.nim
@@ -55,7 +55,7 @@ proc methodCall*(n: PNode; conf: ConfigRef): PNode =
  # replace ordinary method by dispatcher method:
  let disp = getDispatcher(result[0].sym)
  if disp != nil:
-    result[0].typ() = disp.typ
+    result[0].typ = disp.typ
    result[0].sym = disp
    # change the arguments to up/downcasts to fit the dispatcher's parameters:
    for i in 1..<result.len:
@@ -69,23 +69,21 @@ type
 proc sameMethodBucket(a, b: PSym; multiMethods: bool): MethodResult =
  result = No
  if a.name.id != b.name.id: return
-  if a.typ.signatureLen != b.typ.signatureLen:
+  if a.typ.len != b.typ.len:
    return

-  var i = 0
-  for x, y in paramTypePairs(a.typ, b.typ):
-    inc i
-    var aa = x
-    var bb = y
+  for i in 1..<a.typ.len:
+    var aa = a.typ[i]
+    var bb = b.typ[i]
    while true:
      aa = skipTypes(aa, {tyGenericInst, tyAlias})
      bb = skipTypes(bb, {tyGenericInst, tyAlias})
      if aa.kind == bb.kind and aa.kind in {tyVar, tyPtr, tyRef, tyLent, tySink}:
-        aa = aa.elementType
-        bb = bb.elementType
+        aa = aa.lastSon
+        bb = bb.lastSon
      else:
        break
-    if sameType(x, y):
+    if sameType(a.typ[i], b.typ[i]):
      if aa.kind == tyObject and result != Invalid:
        result = Yes
    elif aa.kind == tyObject and bb.kind == tyObject and (i == 1 or multiMethods):
@@ -104,10 +102,10 @@ proc sameMethodBucket(a, b: PSym; multiMethods: bool): MethodResult =
  if result == Yes:
    # check for return type:
    # ignore flags of return types; # bug #22673
-    if not sameTypeOrNil(a.typ.returnType, b.typ.returnType, {IgnoreFlags}):
-      if b.typ.returnType != nil and b.typ.returnType.kind == tyUntyped:
+    if not sameTypeOrNil(a.typ[0], b.typ[0], {IgnoreFlags}):
+      if b.typ[0] != nil and b.typ[0].kind == tyUntyped:
        # infer 'auto' from the base to make it consistent:
-        b.typ.setReturnType a.typ.returnType
+        b.typ[0] = a.typ[0]
      else:
        return No

@@ -133,8 +131,8 @@ proc createDispatcher(s: PSym; g: ModuleGraph; idgen: IdGenerator): PSym =
  if disp.typ.callConv == ccInline: disp.typ.callConv = ccNimCall
  disp.ast = copyTree(s.ast)
  disp.ast[bodyPos] = newNodeI(nkEmpty, s.info)
-  disp.loc.snippet = ""
-  if s.typ.returnType != nil:
+  disp.loc.r = ""
+  if s.typ[0] != nil:
    if disp.ast.len > resultPos:
      disp.ast[resultPos].sym = copySym(s.ast[resultPos].sym, idgen)
    else:
@@ -159,14 +157,9 @@ proc fixupDispatcher(meth, disp: PSym; conf: ConfigRef) =

 proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
  var witness: PSym = nil
-  if s.typ.firstParamType.owner.getModule != s.getModule and vtables in g.config.features and not
-      g.config.isDefined("nimInternalNonVtablesTesting"):
+  if s.typ[1].owner.getModule != s.getModule and vtables in g.config.features and not g.config.isDefined("nimInternalNonVtablesTesting"):
    localError(g.config, s.info, errGenerated, "method `" & s.name.s &
-          "` can be defined only in the same module with its type (" & s.typ.firstParamType.typeToString() & ")")
-  if sfImportc in s.flags:
-    localError(g.config, s.info, errGenerated, "method `" & s.name.s &
-          "` is not allowed to have 'importc' pragmas")
-
+          "` can be defined only in the same module with its type (" & s.typ[1].typeToString() & ")")
  for i in 0..<g.methods.len:
    let disp = g.methods[i].dispatcher
    case sameMethodBucket(disp, s, multimethods = optMultiMethods in g.config.globalOptions)
@@ -186,10 +179,10 @@ proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
      if witness.isNil: witness = g.methods[i].methods[0]
  # create a new dispatcher:
  # stores the id and the position
-  if s.typ.firstParamType.skipTypes(skipPtrs).itemId notin g.bucketTable:
-    g.bucketTable[s.typ.firstParamType.skipTypes(skipPtrs).itemId] = 1
+  if s.typ[1].skipTypes(skipPtrs).itemId notin g.bucketTable:
+    g.bucketTable[s.typ[1].skipTypes(skipPtrs).itemId] = 1
  else:
-    g.bucketTable.inc(s.typ.firstParamType.skipTypes(skipPtrs).itemId)
+    g.bucketTable.inc(s.typ[1].skipTypes(skipPtrs).itemId)
  g.methods.add((methods: @[s], dispatcher: createDispatcher(s, g, idgen)))
  #echo "adding ", s.info
  if witness != nil:
@@ -210,7 +203,7 @@ proc relevantCol*(methods: seq[PSym], col: int): bool =

 proc cmpSignatures(a, b: PSym, relevantCols: IntSet): int =
  result = 0
-  for col in FirstParamAt..<a.typ.signatureLen:
+  for col in 1..<a.typ.len:
    if contains(relevantCols, col):
      var aa = skipTypes(a.typ[col], skipPtrs)
      var bb = skipTypes(b.typ[col], skipPtrs)
@@ -240,13 +233,13 @@ proc sortBucket*(a: var seq[PSym], relevantCols: IntSet) =
 proc genIfDispatcher*(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet; idgen: IdGenerator): PSym =
  var base = methods[0].ast[dispatcherPos].sym
  result = base
-  var paramLen = base.typ.signatureLen
+  var paramLen = base.typ.len
  var nilchecks = newNodeI(nkStmtList, base.info)
  var disp = newNodeI(nkIfStmt, base.info)
  var ands = getSysMagic(g, unknownLineInfo, "and", mAnd)
  var iss = getSysMagic(g, unknownLineInfo, "of", mOf)
  let boolType = getSysType(g, unknownLineInfo, tyBool)
-  for col in FirstParamAt..<paramLen:
+  for col in 1..<paramLen:
    if contains(relevantCols, col):
      let param = base.typ.n[col].sym
      if param.typ.skipTypes(abstractInst).kind in {tyRef, tyPtr}:
@@ -255,7 +248,7 @@ proc genIfDispatcher*(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet;
  for meth in 0..high(methods):
    var curr = methods[meth]      # generate condition:
    var cond: PNode = nil
-    for col in FirstParamAt..<paramLen:
+    for col in 1..<paramLen:
      if contains(relevantCols, col):
        var isn = newNodeIT(nkCall, base.info, boolType)
        isn.add newSymNode(iss)
@@ -270,7 +263,7 @@ proc genIfDispatcher*(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet;
          cond = a
        else:
          cond = isn
-    let retTyp = base.typ.returnType
+    let retTyp = base.typ[0]
    let call = newNodeIT(nkCall, base.info, retTyp)
    call.add newSymNode(curr)
    for col in 1..<paramLen:
@@ -299,7 +292,7 @@ proc genIfDispatcher*(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet;
 proc generateIfMethodDispatchers*(g: ModuleGraph, idgen: IdGenerator) =
  for bucket in 0..<g.methods.len:
    var relevantCols = initIntSet()
-    for col in FirstParamAt..<g.methods[bucket].methods[0].typ.signatureLen:
+    for col in 1..<g.methods[bucket].methods[0].typ.len:
      if relevantCol(g.methods[bucket].methods, col): incl(relevantCols, col)
      if optMultiMethods notin g.config.globalOptions:
        # if multi-methods are not enabled, we are interested only in the first field
--- a/compiler/closureiters.nim
+++ b/compiler/closureiters.nim
@@ -18,8 +18,7 @@
 #    dec a
 #
 # Should be transformed to:
-#  case :state
-#  of 0:
+#  STATE0:
 #    if a > 0:
 #      echo "hi"
 #      :state = 1 # Next state
@@ -27,14 +26,19 @@
 #    else:
 #      :state = 2 # Next state
 #      break :stateLoop # Proceed to the next state
-#  of 1:
+#  STATE1:
 #    dec a
 #    :state = 0 # Next state
 #    break :stateLoop # Proceed to the next state
-#  of 2:
+#  STATE2:
 #    :state = -1 # End of execution
-#  else:
-#    return
+
+# The transformation should play well with lambdalifting, however depending
+# on situation, it can be called either before or after lambdalifting
+# transformation. As such we behave slightly differently, when accessing
+# iterator state, or using temp variables. If lambdalifting did not happen,
+# we just create local variables, so that they will be lifted further on.
+# Otherwise, we utilize existing env, created by lambdalifting.

 # Lambdalifting treats :state variable specially, it should always end up
 # as the first field in env. Currently C codegen depends on this behavior.
@@ -100,13 +104,12 @@
 # Is transformed to (yields are left in place for example simplicity,
 #    in reality the code is subdivided even more, as described above):
 #
-# case :state
-# of 0: # Try
+# STATE0: # Try
 #   yield 0
 #   raise ...
 #   :state = 2 # What would happen should we not raise
 #   break :stateLoop
-# of 1: # Except
+# STATE1: # Except
 #   yield 1
 #   :tmpResult = 3           # Return
 #   :unrollFinally = true # Return
@@ -114,7 +117,7 @@
 #   break :stateLoop
 #   :state = 2 # What would happen should we not return
 #   break :stateLoop
-# of 2: # Finally
+# STATE2: # Finally
 #   yield 2
 #   if :unrollFinally: # This node is created by `newEndFinallyNode`
 #     if :curExc.isNil:
@@ -127,8 +130,6 @@
 #       raise
 #   state = -1 # Goto next state. In this case we just exit
 #   break :stateLoop
-# else:
-#   return

 import
  ast, msgs, idents,
@@ -144,11 +145,12 @@ type
  Ctx = object
    g: ModuleGraph
    fn: PSym
+    stateVarSym: PSym # :state variable. nil if env already introduced by lambdalifting
    tmpResultSym: PSym # Used when we return, but finally has to interfere
    unrollFinallySym: PSym # Indicates that we're unrolling finally states (either exception happened or premature return)
    curExcSym: PSym # Current exception

-    states: seq[tuple[label: int, body: PNode]] # The resulting states.
+    states: seq[PNode] # The resulting states. Every state is an nkState node.
    blockLevel: int # Temp used to transform break and continue stmts
    stateLoopLabel: PSym # Label to break on, when jumping between states.
    exitStateIdx: int # index of the last state
@@ -160,18 +162,17 @@ type
    nearestFinally: int # Index of the nearest finally block. For try/except it
                    # is their finally. For finally it is parent finally. Otherwise -1
    idgen: IdGenerator
-    varStates: Table[ItemId, int] # Used to detect if local variable belongs to multiple states

 const
  nkSkip = {nkEmpty..nkNilLit, nkTemplateDef, nkTypeSection, nkStaticStmt,
-            nkCommentStmt, nkMixinStmt, nkBindStmt, nkTypeOfExpr} + procDefs
-  emptyStateLabel = -1
-  localNotSeen = -1
-  localRequiresLifting = -2
+            nkCommentStmt, nkMixinStmt, nkBindStmt} + procDefs

 proc newStateAccess(ctx: var Ctx): PNode =
-  result = rawIndirectAccess(newSymNode(getEnvParam(ctx.fn)),
-      getStateField(ctx.g, ctx.fn), ctx.fn.info)
+  if ctx.stateVarSym.isNil:
+    result = rawIndirectAccess(newSymNode(getEnvParam(ctx.fn)),
+        getStateField(ctx.g, ctx.fn), ctx.fn.info)
+  else:
+    result = newSymNode(ctx.stateVarSym)

 proc newStateAssgn(ctx: var Ctx, toValue: PNode): PNode =
  # Creates state assignment:
@@ -186,22 +187,28 @@ proc newStateAssgn(ctx: var Ctx, stateNo: int = -2): PNode =
 proc newEnvVar(ctx: var Ctx, name: string, typ: PType): PSym =
  result = newSym(skVar, getIdent(ctx.g.cache, name), ctx.idgen, ctx.fn, ctx.fn.info)
  result.typ = typ
-  result.flags.incl sfNoInit
-  assert(not typ.isNil, "Env var needs a type")
+  assert(not typ.isNil)

-  let envParam = getEnvParam(ctx.fn)
-  # let obj = envParam.typ.lastSon
-  result = addUniqueField(envParam.typ.elementType, result, ctx.g.cache, ctx.idgen)
+  if not ctx.stateVarSym.isNil:
+    # We haven't gone through labmda lifting yet, so just create a local var,
+    # it will be lifted later
+    if ctx.tempVars.isNil:
+      ctx.tempVars = newNodeI(nkVarSection, ctx.fn.info)
+      addVar(ctx.tempVars, newSymNode(result))
+  else:
+    let envParam = getEnvParam(ctx.fn)
+    # let obj = envParam.typ.lastSon
+    result = addUniqueField(envParam.typ.lastSon, result, ctx.g.cache, ctx.idgen)

 proc newEnvVarAccess(ctx: Ctx, s: PSym): PNode =
-  result = rawIndirectAccess(newSymNode(getEnvParam(ctx.fn)), s, ctx.fn.info)
-
-proc newTempVarAccess(ctx: Ctx, s: PSym): PNode =
-  result = newSymNode(s, ctx.fn.info)
+  if ctx.stateVarSym.isNil:
+    result = rawIndirectAccess(newSymNode(getEnvParam(ctx.fn)), s, ctx.fn.info)
+  else:
+    result = newSymNode(s)

 proc newTmpResultAccess(ctx: var Ctx): PNode =
  if ctx.tmpResultSym.isNil:
-    ctx.tmpResultSym = ctx.newEnvVar(":tmpResult", ctx.fn.typ.returnType)
+    ctx.tmpResultSym = ctx.newEnvVar(":tmpResult", ctx.fn.typ[0])
  ctx.newEnvVarAccess(ctx.tmpResultSym)

 proc newUnrollFinallyAccess(ctx: var Ctx, info: TLineInfo): PNode =
@@ -221,7 +228,10 @@ proc newState(ctx: var Ctx, n, gotoOut: PNode): int =

  result = ctx.states.len
  let resLit = ctx.g.newIntLit(n.info, result)
-  ctx.states.add((result, n))
+  let s = newNodeI(nkState, n.info)
+  s.add(resLit)
+  s.add(n)
+  ctx.states.add(s)
  ctx.exceptionTable.add(ctx.curExcHandlingState)

  if not gotoOut.isNil:
@@ -240,18 +250,9 @@ proc addGotoOut(n: PNode, gotoOut: PNode): PNode =
  if result.len == 0 or result[^1].kind != nkGotoState:
    result.add(gotoOut)

-proc newTempVarDef(ctx: Ctx, s: PSym, initialValue: PNode): PNode =
-  var v = initialValue
-  if v == nil:
-    v = ctx.g.emptyNode
-  newTree(nkVarSection, newTree(nkIdentDefs, newSymNode(s), ctx.g.emptyNode, v))
-
-proc newTempVar(ctx: var Ctx, typ: PType, parent: PNode, initialValue: PNode = nil): PSym =
-  result = newSym(skVar, getIdent(ctx.g.cache, ":tmpSlLower" & $ctx.tempVarId), ctx.idgen, ctx.fn, ctx.fn.info)
+proc newTempVar(ctx: var Ctx, typ: PType): PSym =
+  result = ctx.newEnvVar(":tmpSlLower" & $ctx.tempVarId, typ)
  inc ctx.tempVarId
-  result.typ = typ
-  assert(not typ.isNil, "Temp var needs a type")
-  parent.add(ctx.newTempVarDef(result, initialValue))

 proc hasYields(n: PNode): bool =
  # TODO: This is very inefficient. It traverses the node, looking for nkYieldStmt.
@@ -262,8 +263,8 @@ proc hasYields(n: PNode): bool =
    result = false
  else:
    result = false
-    for i in ord(n.kind == nkCast)..<n.len:
-      if n[i].hasYields:
+    for c in n:
+      if c.hasYields:
        result = true
        break

@@ -311,12 +312,12 @@ proc newNullifyCurExc(ctx: var Ctx, info: TLineInfo): PNode =
  let curExc = ctx.newCurExcAccess()
  curExc.info = info
  let nilnode = newNode(nkNilLit)
-  nilnode.typ() = curExc.typ
+  nilnode.typ = curExc.typ
  result = newTree(nkAsgn, curExc, nilnode)

 proc newOr(g: ModuleGraph, a, b: PNode): PNode {.inline.} =
  result = newTree(nkCall, newSymNode(g.getSysMagic(a.info, "or", mOr)), a, b)
-  result.typ() = g.getSysType(a.info, tyBool)
+  result.typ = g.getSysType(a.info, tyBool)
  result.info = a.info

 proc collectExceptState(ctx: var Ctx, n: PNode): PNode {.inline.} =
@@ -334,7 +335,7 @@ proc collectExceptState(ctx: var Ctx, n: PNode): PNode {.inline.} =
            newSymNode(g.getSysMagic(c.info, "of", mOf)),
            g.callCodegenProc("getCurrentException"),
            c[i])
-          nextCond.typ() = ctx.g.getSysType(c.info, tyBool)
+          nextCond.typ = ctx.g.getSysType(c.info, tyBool)
          nextCond.info = c.info

          if cond.isNil:
@@ -412,7 +413,7 @@ proc hasYieldsInExpressions(n: PNode): bool =

 proc exprToStmtList(n: PNode): tuple[s, res: PNode] =
  assert(n.kind == nkStmtListExpr)
-  result = (newNodeI(nkStmtList, n.info), nil)
+  result.s = newNodeI(nkStmtList, n.info)
  result.s.sons = @[]

  var n = n
@@ -423,20 +424,21 @@ proc exprToStmtList(n: PNode): tuple[s, res: PNode] =

  result.res = n

-proc newTempVarAsgn(ctx: Ctx, s: PSym, v: PNode): PNode =
+
+proc newEnvVarAsgn(ctx: Ctx, s: PSym, v: PNode): PNode =
  if isEmptyType(v.typ):
    result = v
  else:
-    result = newTree(nkFastAsgn, ctx.newTempVarAccess(s), v)
+    result = newTree(nkFastAsgn, ctx.newEnvVarAccess(s), v)
    result.info = v.info

 proc addExprAssgn(ctx: Ctx, output, input: PNode, sym: PSym) =
  if input.kind == nkStmtListExpr:
    let (st, res) = exprToStmtList(input)
    output.add(st)
-    output.add(ctx.newTempVarAsgn(sym, res))
+    output.add(ctx.newEnvVarAsgn(sym, res))
  else:
-    output.add(ctx.newTempVarAsgn(sym, input))
+    output.add(ctx.newEnvVarAsgn(sym, input))

 proc convertExprBodyToAsgn(ctx: Ctx, exprBody: PNode, res: PSym): PNode =
  result = newNodeI(nkStmtList, exprBody.info)
@@ -444,17 +446,7 @@ proc convertExprBodyToAsgn(ctx: Ctx, exprBody: PNode, res: PSym): PNode =

 proc newNotCall(g: ModuleGraph; e: PNode): PNode =
  result = newTree(nkCall, newSymNode(g.getSysMagic(e.info, "not", mNot), e.info), e)
-  result.typ() = g.getSysType(e.info, tyBool)
-
-proc boolLit(g: ModuleGraph; info: TLineInfo; value: bool): PNode =
-  result = newIntLit(g, info, ord value)
-  result.typ() = getSysType(g, info, tyBool)
-
-proc captureVar(c: var Ctx, s: PSym) =
-  if c.varStates.getOrDefault(s.itemId) != localRequiresLifting:
-    c.varStates[s.itemId] = localRequiresLifting # Mark this variable for lifting
-    let e = getEnvParam(c.fn)
-    discard addField(e.typ.elementType, s, c.g.cache, c.idgen)
+  result.typ = g.getSysType(e.info, tyBool)

 proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
  result = n
@@ -486,7 +478,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =

      result = newNodeI(nkStmtListExpr, n.info)
      if n.typ.isNil: internalError(ctx.g.config, "lowerStmtListExprs: constr typ.isNil")
-      result.typ() = n.typ
+      result.typ = n.typ

      for i in 0..<n.len:
        case n[i].kind
@@ -512,9 +504,9 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
      var tmp: PSym = nil
      let isExpr = not isEmptyType(n.typ)
      if isExpr:
+        tmp = ctx.newTempVar(n.typ)
        result = newNodeI(nkStmtListExpr, n.info)
-        result.typ() = n.typ
-        tmp = ctx.newTempVar(n.typ, result)
+        result.typ = n.typ
      else:
        result = newNodeI(nkStmtList, n.info)

@@ -565,7 +557,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
        else:
          internalError(ctx.g.config, "lowerStmtListExpr(nkIf): " & $branch.kind)

-      if isExpr: result.add(ctx.newTempVarAccess(tmp))
+      if isExpr: result.add(ctx.newEnvVarAccess(tmp))

  of nkTryStmt, nkHiddenTryStmt:
    var ns = false
@@ -578,8 +570,8 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =

      if isExpr:
        result = newNodeI(nkStmtListExpr, n.info)
-        result.typ() = n.typ
-        let tmp = ctx.newTempVar(n.typ, result)
+        result.typ = n.typ
+        let tmp = ctx.newTempVar(n.typ)

        n[0] = ctx.convertExprBodyToAsgn(n[0], tmp)
        for i in 1..<n.len:
@@ -595,7 +587,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
          else:
            internalError(ctx.g.config, "lowerStmtListExpr(nkTryStmt): " & $branch.kind)
        result.add(n)
-        result.add(ctx.newTempVarAccess(tmp))
+        result.add(ctx.newEnvVarAccess(tmp))

  of nkCaseStmt:
    var ns = false
@@ -608,9 +600,9 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
      let isExpr = not isEmptyType(n.typ)

      if isExpr:
+        let tmp = ctx.newTempVar(n.typ)
        result = newNodeI(nkStmtListExpr, n.info)
-        result.typ() = n.typ
-        let tmp = ctx.newTempVar(n.typ, result)
+        result.typ = n.typ

        if n[0].kind == nkStmtListExpr:
          let (st, ex) = exprToStmtList(n[0])
@@ -627,7 +619,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
          else:
            internalError(ctx.g.config, "lowerStmtListExpr(nkCaseStmt): " & $branch.kind)
        result.add(n)
-        result.add(ctx.newTempVarAccess(tmp))
+        result.add(ctx.newEnvVarAccess(tmp))
      elif n[0].kind == nkStmtListExpr:
        result = newNodeI(nkStmtList, n.info)
        let (st, ex) = exprToStmtList(n[0])
@@ -646,7 +638,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =

      if isExpr:
        result = newNodeI(nkStmtListExpr, n.info)
-        result.typ() = n.typ
+        result.typ = n.typ
      else:
        result = newNodeI(nkStmtList, n.info)

@@ -657,10 +649,10 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
          result.add(st)
          cond = ex

-        let tmp = ctx.newTempVar(cond.typ, result, cond)
-        # result.add(ctx.newTempVarAsgn(tmp, cond))
+        let tmp = ctx.newTempVar(cond.typ)
+        result.add(ctx.newEnvVarAsgn(tmp, cond))

-        var check = ctx.newTempVarAccess(tmp)
+        var check = ctx.newEnvVarAccess(tmp)
        if n[0].sym.magic == mOr:
          check = ctx.g.newNotCall(check)

@@ -670,12 +662,12 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
          let (st, ex) = exprToStmtList(cond)
          ifBody.add(st)
          cond = ex
-        ifBody.add(ctx.newTempVarAsgn(tmp, cond))
+        ifBody.add(ctx.newEnvVarAsgn(tmp, cond))

        let ifBranch = newTree(nkElifBranch, check, ifBody)
        let ifNode = newTree(nkIfStmt, ifBranch)
        result.add(ifNode)
-        result.add(ctx.newTempVarAccess(tmp))
+        result.add(ctx.newEnvVarAccess(tmp))
      else:
        for i in 0..<n.len:
          if n[i].kind == nkStmtListExpr:
@@ -684,9 +676,9 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
            n[i] = ex

          if n[i].kind in nkCallKinds: # XXX: This should better be some sort of side effect tracking
-            let tmp = ctx.newTempVar(n[i].typ, result, n[i])
-            # result.add(ctx.newTempVarAsgn(tmp, n[i]))
-            n[i] = ctx.newTempVarAccess(tmp)
+            let tmp = ctx.newTempVar(n[i].typ)
+            result.add(ctx.newEnvVarAsgn(tmp, n[i]))
+            n[i] = ctx.newEnvVarAccess(tmp)

        result.add(n)

@@ -702,12 +694,6 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
        let (st, ex) = exprToStmtList(c[^1])
        result.add(st)
        c[^1] = ex
-      for i in 0 .. c.len - 3:
-        if c[i].kind == nkSym:
-          let s = c[i].sym
-          if sfForceLift in s.flags:
-            ctx.captureVar(s)
-
      result.add(varSect)

  of nkDiscardStmt, nkReturnStmt, nkRaiseStmt:
@@ -732,7 +718,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
    if ns:
      needsSplit = true
      result = newNodeI(nkStmtListExpr, n.info)
-      result.typ() = n.typ
+      result.typ = n.typ
      let (st, ex) = exprToStmtList(n[^1])
      result.add(st)
      n[^1] = ex
@@ -793,7 +779,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
        let check = newTree(nkIfStmt, branch)
        let newBody = newTree(nkStmtList, st, check, n[1])

-        n[0] = ctx.g.boolLit(n[0].info, true)
+        n[0] = newSymNode(ctx.g.getSysSym(n[0].info, "true"))
        n[1] = newBody

  of nkDotExpr, nkCheckedFieldExpr:
@@ -802,7 +788,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
    if ns:
      needsSplit = true
      result = newNodeI(nkStmtListExpr, n.info)
-      result.typ() = n.typ
+      result.typ = n.typ
      let (st, ex) = exprToStmtList(n[0])
      result.add(st)
      n[0] = ex
@@ -814,10 +800,10 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
    if ns:
      needsSplit = true
      result = newNodeI(nkStmtListExpr, n.info)
-      result.typ() = n.typ
+      result.typ = n.typ
      let (st, ex) = exprToStmtList(n[1])
      n.transitionSonsKind(nkBlockStmt)
-      n.typ() = nil
+      n.typ = nil
      n[1] = st
      result.add(n)
      result.add(ex)
@@ -838,14 +824,14 @@ proc newEndFinallyNode(ctx: var Ctx, info: TLineInfo): PNode =
  #         raise
  let curExc = ctx.newCurExcAccess()
  let nilnode = newNode(nkNilLit)
-  nilnode.typ() = curExc.typ
+  nilnode.typ = curExc.typ
  let cmp = newTree(nkCall, newSymNode(ctx.g.getSysMagic(info, "==", mEqRef), info), curExc, nilnode)
-  cmp.typ() = ctx.g.getSysType(info, tyBool)
+  cmp.typ = ctx.g.getSysType(info, tyBool)

  let retStmt =
    if ctx.nearestFinally == 0:
      # last finally, we can return
-      let retValue = if ctx.fn.typ.returnType.isNil:
+      let retValue = if ctx.fn.typ[0].isNil:
                   ctx.g.emptyNode
                 else:
                   newTree(nkFastAsgn,
@@ -1147,10 +1133,10 @@ proc skipEmptyStates(ctx: Ctx, stateIdx: int): int =
    let label = stateIdx
    if label == ctx.exitStateIdx: break
    var newLabel = label
-    if label == emptyStateLabel:
+    if label == -1:
      newLabel = ctx.exitStateIdx
    else:
-      let fs = skipStmtList(ctx, ctx.states[label].body)
+      let fs = skipStmtList(ctx, ctx.states[label][1])
      if fs.kind == nkGotoState:
        newLabel = fs[0].intVal.int
    if label == newLabel: break
@@ -1159,7 +1145,7 @@ proc skipEmptyStates(ctx: Ctx, stateIdx: int): int =
    if maxJumps == 0:
      assert(false, "Internal error")

-  result = ctx.states[stateIdx].label
+  result = ctx.states[stateIdx][0].intVal.int

 proc skipThroughEmptyStates(ctx: var Ctx, n: PNode): PNode=
  result = n
@@ -1185,11 +1171,11 @@ proc newArrayType(g: ModuleGraph; n: int, t: PType; idgen: IdGenerator; owner: P

 proc createExceptionTable(ctx: var Ctx): PNode {.inline.} =
  result = newNodeI(nkBracket, ctx.fn.info)
-  result.typ() = ctx.g.newArrayType(ctx.exceptionTable.len, ctx.g.getSysType(ctx.fn.info, tyInt16), ctx.idgen, ctx.fn)
+  result.typ = ctx.g.newArrayType(ctx.exceptionTable.len, ctx.g.getSysType(ctx.fn.info, tyInt16), ctx.idgen, ctx.fn)

  for i in ctx.exceptionTable:
    let elem = newIntNode(nkIntLit, i)
-    elem.typ() = ctx.g.getSysType(ctx.fn.info, tyInt16)
+    elem.typ = ctx.g.getSysType(ctx.fn.info, tyInt16)
    result.add(elem)

 proc newCatchBody(ctx: var Ctx, info: TLineInfo): PNode {.inline.} =
@@ -1212,7 +1198,7 @@ proc newCatchBody(ctx: var Ctx, info: TLineInfo): PNode {.inline.} =
    let getNextState = newTree(nkBracketExpr,
      ctx.createExceptionTable(),
      ctx.newStateAccess())
-    getNextState.typ() = intTyp
+    getNextState.typ = intTyp

    # :state = exceptionTable[:state]
    result.add(ctx.newStateAssgn(getNextState))
@@ -1223,7 +1209,7 @@ proc newCatchBody(ctx: var Ctx, info: TLineInfo): PNode {.inline.} =
      ctx.g.getSysMagic(info, "==", mEqI).newSymNode(),
      ctx.newStateAccess(),
      newIntTypeNode(0, intTyp))
-    cond.typ() = boolTyp
+    cond.typ = boolTyp

    let raiseStmt = newTree(nkRaiseStmt, ctx.g.emptyNode)
    let ifBranch = newTree(nkElifBranch, cond, raiseStmt)
@@ -1236,7 +1222,7 @@ proc newCatchBody(ctx: var Ctx, info: TLineInfo): PNode {.inline.} =
      ctx.g.getSysMagic(info, "<", mLtI).newSymNode,
      newIntTypeNode(0, intTyp),
      ctx.newStateAccess())
-    cond.typ() = boolTyp
+    cond.typ = boolTyp

    let asgn = newTree(nkAsgn, ctx.newUnrollFinallyAccess(info), cond)
    result.add(asgn)
@@ -1247,12 +1233,12 @@ proc newCatchBody(ctx: var Ctx, info: TLineInfo): PNode {.inline.} =
      ctx.g.getSysMagic(info, "<", mLtI).newSymNode,
      ctx.newStateAccess(),
      newIntTypeNode(0, intTyp))
-    cond.typ() = boolTyp
+    cond.typ = boolTyp

    let negateState = newTree(nkCall,
      ctx.g.getSysMagic(info, "-", mUnaryMinusI).newSymNode,
      ctx.newStateAccess())
-    negateState.typ() = intTyp
+    negateState.typ = intTyp

    let ifBranch = newTree(nkElifBranch, cond, ctx.newStateAssgn(negateState))
    let ifStmt = newTree(nkIfStmt, ifBranch)
@@ -1277,18 +1263,30 @@ proc wrapIntoTryExcept(ctx: var Ctx, n: PNode): PNode {.inline.} =
 proc wrapIntoStateLoop(ctx: var Ctx, n: PNode): PNode =
  # while true:
  #   block :stateLoop:
+  #     gotoState :state
  #     local vars decl (if needed)
  #     body # Might get wrapped in try-except
  let loopBody = newNodeI(nkStmtList, n.info)
-  result = newTree(nkWhileStmt, ctx.g.boolLit(n.info, true), loopBody)
+  result = newTree(nkWhileStmt, newSymNode(ctx.g.getSysSym(n.info, "true")), loopBody)
  result.info = n.info

  let localVars = newNodeI(nkStmtList, n.info)
+  if not ctx.stateVarSym.isNil:
+    let varSect = newNodeI(nkVarSection, n.info)
+    addVar(varSect, newSymNode(ctx.stateVarSym))
+    localVars.add(varSect)
+
+    if not ctx.tempVars.isNil:
+      localVars.add(ctx.tempVars)

  let blockStmt = newNodeI(nkBlockStmt, n.info)
  blockStmt.add(newSymNode(ctx.stateLoopLabel))

-  var blockBody = newTree(nkStmtList, localVars, n)
+  let gs = newNodeI(nkGotoState, n.info)
+  gs.add(ctx.newStateAccess())
+  gs.add(ctx.g.newIntLit(n.info, ctx.states.len - 1))
+
+  var blockBody = newTree(nkStmtList, gs, localVars, n)
  if ctx.hasExceptions:
    blockBody = ctx.wrapIntoTryExcept(blockBody)

@@ -1301,28 +1299,29 @@ proc deleteEmptyStates(ctx: var Ctx) =

  # Apply new state indexes and mark unused states with -1
  var iValid = 0
-  for i, s in ctx.states.mpairs:
-    let body = skipStmtList(ctx, s.body)
+  for i, s in ctx.states:
+    let body = skipStmtList(ctx, s[1])
    if body.kind == nkGotoState and i != ctx.states.len - 1 and i != 0:
      # This is an empty state. Mark with -1.
-      s.label = emptyStateLabel
+      s[0].intVal = -1
    else:
-      s.label = iValid
+      s[0].intVal = iValid
      inc iValid

  for i, s in ctx.states:
-    let body = skipStmtList(ctx, s.body)
+    let body = skipStmtList(ctx, s[1])
    if body.kind != nkGotoState or i == 0:
-      discard ctx.skipThroughEmptyStates(s.body)
+      discard ctx.skipThroughEmptyStates(s)
      let excHandlState = ctx.exceptionTable[i]
      if excHandlState < 0:
        ctx.exceptionTable[i] = -ctx.skipEmptyStates(-excHandlState)
      elif excHandlState != 0:
        ctx.exceptionTable[i] = ctx.skipEmptyStates(excHandlState)

-  var i = 1 # ignore the entry and the exit
+  var i = 0
  while i < ctx.states.len - 1:
-    if ctx.states[i].label == emptyStateLabel:
+    let fs = skipStmtList(ctx, ctx.states[i][1])
+    if fs.kind == nkGotoState and i != 0:
      ctx.states.delete(i)
      ctx.exceptionTable.delete(i)
    else:
@@ -1431,81 +1430,18 @@ proc preprocess(c: var PreprocessContext; n: PNode): PNode =
    for i in 0 ..< n.len:
      result[i] = preprocess(c, n[i])

-proc detectCapturedVars(c: var Ctx, n: PNode, stateIdx: int) =
-  case n.kind
-  of nkSym:
-    let s = n.sym
-    if s.kind in {skResult, skVar, skLet, skForVar, skTemp} and sfGlobal notin s.flags and s.owner == c.fn:
-      let vs = c.varStates.getOrDefault(s.itemId, localNotSeen)
-      if vs == localNotSeen: # First seing this variable
-        c.varStates[s.itemId] = stateIdx
-      elif vs == localRequiresLifting:
-        discard # Sym already marked
-      elif vs != stateIdx:
-        c.captureVar(s)
-  of nkReturnStmt:
-    if n[0].kind in {nkAsgn, nkFastAsgn, nkSinkAsgn}:
-      # we have a `result = result` expression produced by the closure
-      # transform, let's not touch the LHS in order to make the lifting pass
-      # correct when `result` is lifted
-      detectCapturedVars(c, n[0][1], stateIdx)
-    else:
-      detectCapturedVars(c, n[0], stateIdx)
-  of nkEmpty..pred(nkSym), succ(nkSym)..nkNilLit,
-     nkTemplateDef, nkTypeSection, nkProcDef, nkMethodDef,
-     nkConverterDef, nkMacroDef, nkFuncDef, nkCommentStmt,
-     nkTypeOfExpr, nkMixinStmt, nkBindStmt:
-    discard
-  of nkLambdaKinds, nkIteratorDef:
-    if n.typ != nil:
-      detectCapturedVars(c, n[namePos], stateIdx)
-  else:
-    for i in 0 ..< n.safeLen:
-      detectCapturedVars(c, n[i], stateIdx)
-
-proc detectCapturedVars(c: var Ctx) =
-  for i, s in c.states:
-    detectCapturedVars(c, s.body, i)
-
-proc liftLocals(c: var Ctx, n: PNode): PNode =
-  result = n
-  case n.kind
-  of nkSym:
-    let s = n.sym
-    if c.varStates.getOrDefault(s.itemId) == localRequiresLifting:
-      # lift
-      let e = getEnvParam(c.fn)
-      let field = getFieldFromObj(e.typ.elementType, s)
-      assert(field != nil)
-      result = rawIndirectAccess(newSymNode(e), field, n.info)
-    # elif c.varStates.getOrDefault(s.itemId, localNotSeen) != localNotSeen:
-    #   echo "Not lifting ", s.name.s
-
-  of nkReturnStmt:
-    if n[0].kind in {nkAsgn, nkFastAsgn, nkSinkAsgn}:
-      # we have a `result = result` expression produced by the closure
-      # transform, let's not touch the LHS in order to make the lifting pass
-      # correct when `result` is lifted
-      n[0][1] = liftLocals(c, n[0][1])
-    else:
-      n[0] = liftLocals(c, n[0])
-  of nkEmpty..pred(nkSym), succ(nkSym)..nkNilLit,
-     nkTemplateDef, nkTypeSection, nkProcDef, nkMethodDef,
-     nkConverterDef, nkMacroDef, nkFuncDef, nkCommentStmt,
-     nkTypeOfExpr, nkMixinStmt, nkBindStmt,
-     nkLambdaKinds, nkIteratorDef:
-    discard
-  else:
-    for i in 0 ..< n.safeLen:
-      n[i] = liftLocals(c, n[i])
-
 proc transformClosureIterator*(g: ModuleGraph; idgen: IdGenerator; fn: PSym, n: PNode): PNode =
-  var ctx = Ctx(g: g, fn: fn, idgen: idgen)
-
-  # The transformation should always happen after at least partial lambdalifting
-  # is performed, so that the closure iter environment is always created upfront.
-  doAssert(getEnvParam(fn) != nil, "Env param not created before iter transformation")
+  var ctx: Ctx
+  ctx.g = g
+  ctx.fn = fn
+  ctx.idgen = idgen

+  if getEnvParam(fn).isNil:
+    # Lambda lifting was not done yet. Use temporary :state sym, which will
+    # be handled specially by lambda lifting. Local temp vars (if needed)
+    # should follow the same logic.
+    ctx.stateVarSym = newSym(skVar, getIdent(ctx.g.cache, ":state"), idgen, fn, fn.info)
+    ctx.stateVarSym.typ = g.createClosureIterStateType(fn, idgen)
  ctx.stateLoopLabel = newSym(skLabel, getIdent(ctx.g.cache, ":stateLoop"), idgen, fn, fn.info)
  var pc = PreprocessContext(finallys: @[], config: g.config, idgen: idgen)
  var n = preprocess(pc, n.toStmtList)
@@ -1527,21 +1463,17 @@ proc transformClosureIterator*(g: ModuleGraph; idgen: IdGenerator; fn: PSym, n:
  # Optimize empty states away
  ctx.deleteEmptyStates()

-  let caseDispatcher = newTreeI(nkCaseStmt, n.info,
-      ctx.newStateAccess())
-
-  # Lamdalifting will not touch our locals, it is our responsibility to lift those that
-  # need it.
-  detectCapturedVars(ctx)
-
+  # Make new body by concatenating the list of states
+  result = newNodeI(nkStmtList, n.info)
  for s in ctx.states:
-    let body = ctx.transformStateAssignments(s.body)
-    caseDispatcher.add newTreeI(nkOfBranch, body.info, g.newIntLit(body.info, s.label), body)
+    assert(s.len == 2)
+    let body = s[1]
+    s.sons.del(1)
+    result.add(s)
+    result.add(body)

-  caseDispatcher.add newTreeI(nkElse, n.info, newTreeI(nkReturnStmt, n.info, g.emptyNode))
-
-  result = wrapIntoStateLoop(ctx, caseDispatcher)
-  result = liftLocals(ctx, result)
+  result = ctx.transformStateAssignments(result)
+  result = ctx.wrapIntoStateLoop(result)

  when false:
    echo "TRANSFORM TO STATES: "
@@ -1550,5 +1482,3 @@ proc transformClosureIterator*(g: ModuleGraph; idgen: IdGenerator; fn: PSym, n:
    echo "exception table:"
    for i, e in ctx.exceptionTable:
      echo i, " -> ", e
-
-    echo "ENV: ", renderTree(getEnvParam(fn).typ.elementType.n)
--- a/compiler/cmdlinehelper.nim
+++ b/compiler/cmdlinehelper.nim
@@ -57,11 +57,6 @@ proc loadConfigsAndProcessCmdLine*(self: NimProg, cache: IdentCache; conf: Confi
  if conf.cmd == cmdNimscript:
    incl(conf.globalOptions, optWasNimscript)
  loadConfigs(DefaultConfig, cache, conf, graph.idgen) # load all config files
-  # restores `conf.notes` after loading config files
-  # because it has overwrites the notes when compiling the system module which
-  # is a foreign module compared to the project
-  if conf.cmd in cmdBackends:
-    conf.notes = conf.mainPackageNotes

  if not self.suggestMode:
    let scriptFile = conf.projectFull.changeFileExt("nims")
--- a/compiler/commands.nim
+++ b/compiler/commands.nim
@@ -24,7 +24,7 @@ bootSwitch(usedMarkAndSweep, defined(gcmarkandsweep), "--gc:markAndSweep")
 bootSwitch(usedGoGC, defined(gogc), "--gc:go")
 bootSwitch(usedNoGC, defined(nogc), "--gc:none")

-import std/[setutils, os, strutils, parseutils, parseopt, sequtils, strtabs, enumutils]
+import std/[setutils, os, strutils, parseutils, parseopt, sequtils, strtabs]
 import
  msgs, options, nversion, condsyms, extccomp, platform,
  wordrecg, nimblecmd, lineinfos, pathutils
@@ -203,14 +203,13 @@ proc processSpecificNote*(arg: string, state: TSpecialWord, pass: TCmdLinePass,
  else: invalidCmdLineOption(conf, pass, orig, info)

  let isSomeHint = state in {wHint, wHintAsError}
-  let isSomeWarning = state in {wWarning, wWarningAsError}
  template findNote(noteMin, noteMax, name) =
    # unfortunately, hintUser and warningUser clash, otherwise implementation would simplify a bit
    let x = findStr(noteMin, noteMax, id, errUnknown)
    if x != errUnknown: notes = {TNoteKind(x)}
    else:
-      if isSomeHint or isSomeWarning:
-        message(conf, info, warnUnknownNotes, "unknown $#: $#" % [name, id])
+      if isSomeHint:
+        message(conf, info, hintUnknownHint, id)
      else:
        localError(conf, info, "unknown $#: $#" % [name, id])
  case id.normalize
@@ -249,7 +248,6 @@ const
  errNoneSpeedOrSizeExpectedButXFound = "'none', 'speed' or 'size' expected, but '$1' found"
  errGuiConsoleOrLibExpectedButXFound = "'gui', 'console', 'lib' or 'staticlib' expected, but '$1' found"
  errInvalidExceptionSystem = "'goto', 'setjmp', 'cpp' or 'quirky' expected, but '$1' found"
-  errInvalidFeatureButXFound = Feature.toSeq.map(proc(val:Feature): string = "'$1'" % $val).join(", ") & " expected, but '$1' found"

 template warningOptionNoop(switch: string) =
  warningDeprecated(conf, info, "'$#' is deprecated, now a noop" % switch)
@@ -305,12 +303,6 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
    else:
      result = false
      localError(conf, info, errInvalidExceptionSystem % arg)
-  of "experimental":
-    try:
-      result = conf.features.contains parseEnum[Feature](arg)
-    except ValueError:
-      result = false
-      localError(conf, info, errInvalidFeatureButXFound % arg)
  else:
    result = false
    invalidCmdLineOption(conf, passCmd1, switch, info)
@@ -459,7 +451,7 @@ template handleStdinOrCmdInput =
    conf.outDir = getNimcacheDir(conf)

 proc handleStdinInput*(conf: ConfigRef) =
-  conf.projectName = conf.stdinFile.string
+  conf.projectName = "stdinfile"
  conf.projectIsStdin = true
  handleStdinOrCmdInput()

@@ -470,6 +462,7 @@ proc handleCmdInput*(conf: ConfigRef) =
 proc parseCommand*(command: string): Command =
  case command.normalize
  of "c", "cc", "compile", "compiletoc": cmdCompileToC
+  of "nir": cmdCompileToNir
  of "cpp", "compiletocpp": cmdCompileToCpp
  of "objc", "compiletooc": cmdCompileToOC
  of "js", "compiletojs": cmdCompileToJS
@@ -507,6 +500,7 @@ proc setCmd*(conf: ConfigRef, cmd: Command) =
  of cmdCompileToCpp: conf.backend = backendCpp
  of cmdCompileToOC: conf.backend = backendObjc
  of cmdCompileToJS: conf.backend = backendJs
+  of cmdCompileToNir: conf.backend = backendNir
  else: discard

 proc setCommandEarly*(conf: ConfigRef, command: string) =
@@ -920,12 +914,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
    discard parseSaturatedNatural(arg, value)
    if not value > 0: localError(conf, info, "maxLoopIterationsVM must be a positive integer greater than zero")
    conf.maxLoopIterationsVM = value
-  of "maxcalldepthvm":
-    expectArg(conf, switch, arg, pass, info)
-    var value: int = 2_000
-    discard parseSaturatedNatural(arg, value)
-    if value <= 0: localError(conf, info, "maxCallDepthVM must be a positive integer greater than zero")
-    conf.maxCallDepthVM = value
  of "errormax":
    expectArg(conf, switch, arg, pass, info)
    # Note: `nim check` (etc) can overwrite this.
@@ -935,10 +923,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
    var value: int = 0
    discard parseSaturatedNatural(arg, value)
    conf.errorMax = if value == 0: high(int) else: value
-  of "stdinfile":
-    expectArg(conf, switch, arg, pass, info)
-    conf.stdinFile = if os.isAbsolute(arg): AbsoluteFile(arg)
-                     else: AbsoluteFile(getCurrentDir() / arg)
  of "verbosity":
    expectArg(conf, switch, arg, pass, info)
    let verbosity = parseInt(arg)
--- a/compiler/concepts.nim
+++ b/compiler/concepts.nim
@@ -11,7 +11,7 @@
 ## for details. Note this is a first implementation and only the "Concept matching"
 ## section has been implemented.

-import ast, astalgo, semdata, lookups, lineinfos, idents, msgs, renderer, types, layeredtable
+import ast, astalgo, semdata, lookups, lineinfos, idents, msgs, renderer, types

 import std/intsets

@@ -19,7 +19,7 @@ when defined(nimPreviewSlimSystem):
  import std/assertions

 const
-  logBindings = when defined(debugConcepts): true else: false
+  logBindings = false

 ## Code dealing with Concept declarations
 ## --------------------------------------
@@ -70,364 +70,157 @@ proc semConceptDeclaration*(c: PContext; n: PNode): PNode =
 ## ----------------

 type
-  MatchFlags* = enum
-    mfDontBind  # Do not bind generic parameters
-    mfCheckGeneric  # formal <- formal comparison as opposed to formal <- operand
-  
  MatchCon = object ## Context we pass around during concept matching.
-    bindings: LayeredIdTable
+    inferred: seq[(PType, PType)] ## we need a seq here so that we can easily undo inferences \
+      ## that turned out to be wrong.
    marker: IntSet ## Some protection against wild runaway recursions.
    potentialImplementation: PType ## the concrete type that might match the concept we try to match.
    magic: TMagic  ## mArrGet and mArrPut is wrong in system.nim and
                   ## cannot be fixed that easily.
                   ## Thus we special case it here.
-    concpt: PType  ## current concept being evaluated
-    depthCount = 0
-    flags: set[MatchFlags]
-    
-  MatchKind = enum
-    mkNoMatch, mkSubset, mkSame
-
-const
-  asymmetricConceptParamMods = {tyVar, tySink, tyLent, tyOwned, tyAlias, tyInferred} # param modifiers that to not have to match implementation -> concept
-  bindableTypes = {tyGenericParam, tyOr, tyTypeDesc}
-
-proc conceptMatchNode(c: PContext; n: PNode; m: var MatchCon): bool
-
-proc matchType(c: PContext; fo, ao: PType; m: var MatchCon): bool
-
-proc matchReturnType(c: PContext; f, a: PType; m: var MatchCon): bool
-
-proc processConcept(c: PContext; concpt, invocation: PType, bindings: var LayeredIdTable; m: var MatchCon): bool

 proc existingBinding(m: MatchCon; key: PType): PType =
  ## checks if we bound the type variable 'key' already to some
  ## concrete type.
-  result = m.bindings.lookup(key)
-  if result == nil:
-    result = key
+  for i in 0..<m.inferred.len:
+    if m.inferred[i][0] == key: return m.inferred[i][1]
+  return nil

-const
-    ignorableForArgType = {tyVar, tySink, tyLent, tyOwned, tyAlias, tyInferred}
+proc conceptMatchNode(c: PContext; n: PNode; m: var MatchCon): bool

-proc unrollGenericParam(param: PType): PType =
-  result = param.skipTypes(ignorableForArgType)
-  while result.kind in {tyGenericParam, tyTypeDesc} and result.hasElementType and result.elementType.kind != tyNone:
-    result = result.elementType
-
-proc bindParam(c: PContext, m: var MatchCon; key, v: PType): bool {. discardable .} =
-  if v.kind == tyTypeDesc:
-    return false
-  var value = unrollGenericParam(v)
-  if value.kind == tyGenericParam:
-    value = existingBinding(m, value)
-    if value.kind == tyGenericParam:
-      if value.hasElementType:
-        value = value.elementType
-      else:
-        return true
-  if value.kind == tyStatic:
-    return false
-
-  if m.magic in {mArrPut, mArrGet} and value.kind in arrPutGetMagicApplies:
-    value = value.last
-  
-  let old = existingBinding(m, key)
-  if old != key:
-    # check previously bound value
-    if not matchType(c, old, value, m):
-      return false
-  elif key.hasElementType and key.elementType.kind != tyNone:
-    # check constaint
-    if matchType(c, unrollGenericParam(key), value, m) == false:
-      return false
-  
-  when logBindings: echo "bind table adding '", key, "', ", value
-  assert value != nil
-  assert value.kind != tyVoid
-  m.bindings.put(key, value)
-  return true
-
-proc defSignatureType(n: PNode): PType = n[0].sym.typ
-
-proc conceptBody*(n: PType): PNode = n.n.lastSon
-
-proc acceptsAllTypes(t: PType): bool=
-  result = false
-  if t.kind == tyAnything:
-    result = true
-  elif t.kind == tyGenericParam:
-    if tfImplicitTypeParam in t.flags:
-      result = true
-    if not t.hasElementType or t.elementType.kind == tyNone:
-      result = true
-
-proc procDefSignature(s: PSym): PNode {. deprecated .} = 
-  var nc = s.ast.copyNode()
-  for i in 0 .. 5:
-    nc.add s.ast[i]
-  nc
-
-proc matchKids(c: PContext; f, a: PType; m: var MatchCon, start=0): bool=
-  result = true
-  for i in start ..< f.kidsLen - ord(f.kind in {tyGenericInst, tyGenericInvocation}):
-    if not matchType(c, f[i], a[i], m): return false
-
-iterator traverseTyOr(t: PType): PType {. closure .}=
-  for i in t.kids:
-    case i.kind:
-    of tyGenericParam:
-      if i.hasElementType:
-        for s in traverseTyOr(i.elementType):
-          yield s
-      else:
-        yield i
-    else:
-      yield i
-
-proc matchConceptToImpl(c: PContext, f, potentialImpl: PType; m: var MatchCon): bool =
-  assert not(potentialImpl.reduceToBase.kind == tyConcept)
-  let concpt = f.reduceToBase
-  if m.depthCount > 0:
-    # concepts that are more then 2 levels deep are treated like
-    # tyAnything to stop dependencies from getting out of control
-    return true
-  var efPot = potentialImpl
-  if potentialImpl.isSelf:
-    if m.concpt.n == concpt.n:
-      return true
-    efPot = m.potentialImplementation
-  
-  var oldBindings = m.bindings
-  m.bindings = newTypeMapLayer(m.bindings)
-  let oldPotentialImplementation = m.potentialImplementation
-  m.potentialImplementation = efPot
-  let oldConcept = m.concpt
-  m.concpt = concpt
-  
-  var invocation: PType = nil
-  if f.kind in {tyGenericInvocation, tyGenericInst}:
-    invocation = f
-  inc m.depthCount
-  result = processConcept(c, concpt, invocation, oldBindings, m)
-  dec m.depthCount
-  m.potentialImplementation = oldPotentialImplementation
-  m.concpt = oldConcept
-  m.bindings = oldBindings
-
-proc cmpConceptDefs(c: PContext, fn, an: PNode, m: var MatchCon): bool=
-  if fn.kind != an.kind:
-    return false
-  if fn[namePos].sym.name != an[namePos].sym.name:
-    return false
-  let
-    ft = fn.defSignatureType
-    at = an.defSignatureType
-  if ft.len != at.len:
-    return false
-  
-  for i in 1 ..< ft.n.len:
-    m.bindings = m.bindings.newTypeMapLayer()
-    
-    let aType = at.n[i].typ
-    let fType = ft.n[i].typ
-    
-    if aType.isSelf and fType.isSelf:
-      continue
-    
-    if not matchType(c, fType, aType, m):
-      m.bindings.setToPreviousLayer()
-      return false
-  result = true
-  if not matchReturnType(c, ft.returnType, at.returnType, m):
-    m.bindings.setToPreviousLayer()
-    result = false
-
-proc conceptsMatch(c: PContext, fc, ac: PType; m: var MatchCon): MatchKind =
-  # XXX: In the future this may need extra parameters to carry info for container types
-  if fc.n == ac.n:
-    # This will have to take generic parameters into account at some point
-    return mkSame
-  let
-    fn = fc.conceptBody
-    an = ac.conceptBody
-    sameLen = fc.len == ac.len
-  var match = false
-  for fdef in fn:
-    var cmpResult = false
-    for ia, ndef in an:
-      match = cmpConceptDefs(c, fdef, ndef, m)
-      if match:
-        break
-    if not match:
-      return mkNoMatch
-  return mkSubset
-
-proc matchType(c: PContext; fo, ao: PType; m: var MatchCon): bool =
+proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
  ## The heart of the concept matching process. 'f' is the formal parameter of some
  ## routine inside the concept that we're looking for. 'a' is the formal parameter
  ## of a routine that might match.
-  
-  var
-    a = ao
-    f = fo
-  
-  if a.kind in bindableTypes:
-    a = existingBinding(m, ao)
-    if a == ao and a.kind == tyGenericParam and a.hasElementType and a.elementType.kind != tyNone:
-      a = a.elementType
-  
-  if f.isConcept:
-    if a.acceptsAllTypes:
-      return false
-    if a.skipTypes(ignorableForArgType).isConcept:
-      # if f is a subset of a then any match to a will also match f. Not the other way around
-      return conceptsMatch(c, a.reduceToBase, f.reduceToBase, m) >= mkSubset
-    else:
-      return matchConceptToImpl(c, f, a, m)
-  
-  result = false
-
+  const
+    ignorableForArgType = {tyVar, tySink, tyLent, tyOwned, tyGenericInst, tyAlias, tyInferred}
  case f.kind
  of tyAlias:
-    result = matchType(c, f.skipModifier, a, m)
+    result = matchType(c, f.lastSon, a, m)
  of tyTypeDesc:
    if isSelf(f):
-      let ua = a.skipTypes(asymmetricConceptParamMods)
-      if m.magic in {mArrPut, mArrGet}:
-        if m.potentialImplementation.reduceToBase.kind in arrPutGetMagicApplies:
-          bindParam(c, m, a, last m.potentialImplementation)
-          result = true
-      #elif ua.isConcept:
-      #  result = matchType(c, m.concpt, ua, m)
-      else:
-        result = matchType(c, a.skipTypes(ignorableForArgType), m.potentialImplementation, m)
+      #let oldLen = m.inferred.len
+      result = matchType(c, a, m.potentialImplementation, m)
+      #echo "self is? ", result, " ", a.kind, " ", a, " ", m.potentialImplementation, " ", m.potentialImplementation.kind
+      #m.inferred.setLen oldLen
+      #echo "A for ", result, " to ", typeToString(a), " to ", typeToString(m.potentialImplementation)
    else:
-      if a.kind == tyTypeDesc:
-        if not(a.hasElementType) or a.elementType.kind == tyNone:
+      if a.kind == tyTypeDesc and f.len == a.len:
+        for i in 0..<a.len:
+          if not matchType(c, f[i], a[i], m): return false
+        return true
+      else:
+        result = false
+
+  of tyGenericInvocation:
+    result = false
+    if a.kind == tyGenericInst and a[0].kind == tyGenericBody:
+      if sameType(f[0], a[0]) and f.len == a.len-1:
+        for i in 1 ..< f.len:
+          if not matchType(c, f[i], a[i], m): return false
+        return true
+  of tyGenericParam:
+    let ak = a.skipTypes({tyVar, tySink, tyLent, tyOwned})
+    if ak.kind in {tyTypeDesc, tyStatic} and not isSelf(ak):
+      result = false
+    else:
+      let old = existingBinding(m, f)
+      if old == nil:
+        if f.len > 0 and f[0].kind != tyNone:
+          # also check the generic's constraints:
+          let oldLen = m.inferred.len
+          result = matchType(c, f[0], a, m)
+          m.inferred.setLen oldLen
+          if result:
+            when logBindings: echo "A adding ", f, " ", ak
+            m.inferred.add((f, ak))
+        elif m.magic == mArrGet and ak.kind in {tyArray, tyOpenArray, tySequence, tyVarargs, tyCstring, tyString}:
+          when logBindings: echo "B adding ", f, " ", lastSon ak
+          m.inferred.add((f, lastSon ak))
          result = true
-        elif f.hasElementType:
-          result = matchType(c, f.elementType, a.elementType, m)
+        else:
+          when logBindings: echo "C adding ", f, " ", ak
+          m.inferred.add((f, ak))
+          #echo "binding ", typeToString(ak), " to ", typeToString(f)
+          result = true
+      elif not m.marker.containsOrIncl(old.id):
+        result = matchType(c, old, ak, m)
+        if m.magic == mArrPut and ak.kind == tyGenericParam:
+          result = true
+      else:
+        result = false
+    #echo "B for ", result, " to ", typeToString(a), " to ", typeToString(m.potentialImplementation)
+
  of tyVar, tySink, tyLent, tyOwned:
    # modifiers in the concept must be there in the actual implementation
    # too but not vice versa.
    if a.kind == f.kind:
-      result = matchType(c, f.elementType, a.elementType, m)
+      result = matchType(c, f[0], a[0], m)
    elif m.magic == mArrPut:
-      result = matchType(c, f.elementType, a, m)
-  of tyEnum, tyObject, tyDistinct:
-    if a.kind in ignorableForArgType:
-      result = matchType(c, f, a.skipTypes(ignorableForArgType), m)
+      result = matchType(c, f[0], a, m)
    else:
-      if a.kind == tyGenericInst:
-        # tyOr does this to generic typeclasses
-        result = a.base.sym == f.sym
-      else:
-        result = sameType(f, a)
+      result = false
+  of tyEnum, tyObject, tyDistinct:
+    result = sameType(f, a)
  of tyEmpty, tyString, tyCstring, tyPointer, tyNil, tyUntyped, tyTyped, tyVoid:
    result = a.skipTypes(ignorableForArgType).kind == f.kind
  of tyBool, tyChar, tyInt..tyUInt64:
    let ak = a.skipTypes(ignorableForArgType)
    result = ak.kind == f.kind or ak.kind == tyOrdinal or
-      (ak.kind == tyGenericParam and ak.hasElementType and ak.elementType.kind == tyOrdinal)
-  of tyArray, tyTuple, tyVarargs, tyOpenArray, tyRange, tySequence, tyRef, tyPtr:
-    if f.kind == tyArray and f.kidsLen == 3 and a.kind == tyArray:
-      # XXX: this is a work-around!
-      # system.nim creates these for the magic array typeclass
-      result = true
-    else:
-      let ak = a.skipTypes(ignorableForArgType - {f.kind})
-      if ak.kind == f.kind and f.kidsLen == ak.kidsLen:
-        result = matchKids(c, f, ak, m)
-  of tyGenericInvocation, tyGenericInst:
+       (ak.kind == tyGenericParam and ak.len > 0 and ak[0].kind == tyOrdinal)
+  of tyConcept:
+    let oldLen = m.inferred.len
+    let oldPotentialImplementation = m.potentialImplementation
+    m.potentialImplementation = a
+    result = conceptMatchNode(c, f.n.lastSon, m)
+    m.potentialImplementation = oldPotentialImplementation
+    if not result:
+      m.inferred.setLen oldLen
+  of tyArray, tyTuple, tyVarargs, tyOpenArray, tyRange, tySequence, tyRef, tyPtr,
+     tyGenericInst:
    result = false
-    let ea = a.skipTypes(ignorableForArgType)
-    if ea.kind in {tyGenericInst, tyGenericInvocation}:
-      var
-        k1 = f.kidsLen - ord(f.kind == tyGenericInst)
-        k2 = ea.kidsLen - ord(ea.kind == tyGenericInst)
-      if sameType(f.genericHead, ea.genericHead) and k1 == k2:
-        result = true
-        for i in 1 ..< k2:
-          if not matchType(c, f[i], ea[i], m):
-            result = false
-            break
-  of tyOrdinal:
-    result = isOrdinalType(a, allowEnumWithHoles = false) or a.kind == tyGenericParam
-  of tyStatic:
-    var scomp = f.base
-    if scomp.kind == tyGenericParam:
-      if f.base.kidsLen > 0:
-        scomp = scomp.base
-    if a.kind == tyStatic:
-      result = matchType(c, scomp, a.base, m)
-    else:
-      result = matchType(c, scomp, a, m)
-  of tyGenericParam:
-    if a.acceptsAllTypes:
-      discard bindParam(c, m, f, a)
-      result = f.acceptsAllTypes
-    else:
-      result = bindParam(c, m, f, a)
-  of tyAnything:
-    result = true
-  of tyNot:
-    if a.kind == tyNot:
-      result = matchType(c, f.elementType, a.elementType, m)
-    else:
-      m.bindings = m.bindings.newTypeMapLayer()
-      result = not matchType(c, f.elementType, a, m)
-      m.bindings.setToPreviousLayer()
-  of tyAnd:
-    m.bindings = m.bindings.newTypeMapLayer()
-    result = true
-    for ff in traverseTyOr(f):
-      let r = matchType(c, ff, a, m)
-      if not r:
-        m.bindings.setToPreviousLayer()
-        result = false
-        break
-  of tyGenericBody:
-    var ak = a
-    if a.kind == tyGenericBody:
-      ak = last(a)
-    result = matchType(c, last(f), ak, m)
-  of tyCompositeTypeClass:
-    if a.kind == tyCompositeTypeClass:
-      result = matchKids(c, f, a, m)
-    else:
-      result = matchType(c, last(f), a, m)
-  of tyBuiltInTypeClass:
-    let target = f.genericHead.kind
-    result = a.skipTypes(ignorableForArgType).reduceToBase.kind == target
+    let ak = a.skipTypes(ignorableForArgType - {f.kind})
+    if ak.kind == f.kind and f.len == ak.len:
+      for i in 0..<ak.len:
+        if not matchType(c, f[i], ak[i], m): return false
+      return true
  of tyOr:
+    let oldLen = m.inferred.len
    if a.kind == tyOr:
+      # say the concept requires 'int|float|string' if the potentialImplementation
+      # says 'int|string' that is good enough.
      var covered = 0
-      for ff in traverseTyOr(f):
-        for aa in traverseTyOr(a):
-          m.bindings = m.bindings.newTypeMapLayer()
-          let r = matchType(c, ff, aa, m)
+      for i in 0..<f.len:
+        for j in 0..<a.len:
+          let oldLenB = m.inferred.len
+          let r = matchType(c, f[i], a[j], m)
          if r:
            inc covered
            break
-          m.bindings.setToPreviousLayer()
+          m.inferred.setLen oldLenB

-      result = covered >= a.kidsLen
+      result = covered >= a.len
+      if not result:
+        m.inferred.setLen oldLen
    else:
-      for ff in f.kids:
-        m.bindings = m.bindings.newTypeMapLayer()
-        result = matchType(c, ff, a, m)
+      result = false
+      for i in 0..<f.len:
+        result = matchType(c, f[i], a, m)
        if result: break # and remember the binding!
-        m.bindings.setToPreviousLayer()
+        m.inferred.setLen oldLen
+  of tyNot:
+    if a.kind == tyNot:
+      result = matchType(c, f[0], a[0], m)
+    else:
+      let oldLen = m.inferred.len
+      result = not matchType(c, f[0], a, m)
+      m.inferred.setLen oldLen
+  of tyAnything:
+    result = true
+  of tyOrdinal:
+    result = isOrdinalType(a, allowEnumWithHoles = false) or a.kind == tyGenericParam
  else:
    result = false
-  if result and ao.kind == tyGenericParam:
-    let bf = if f.isSelf: m.potentialImplementation else: f
-    if bindParam(c, m, ao, bf):
-      when logBindings: echo " ^ reverse binding"
-
-proc checkConstraint(c: PContext; f, a: PType; m: var MatchCon): bool =
-  result = matchType(c, f, a, m) or matchType(c, a, f, m)

 proc matchReturnType(c: PContext; f, a: PType; m: var MatchCon): bool =
  ## Like 'matchType' but with extra logic dealing with proc return types
@@ -437,38 +230,30 @@ proc matchReturnType(c: PContext; f, a: PType; m: var MatchCon): bool =
  elif a == nil:
    result = false
  else:
-    result = checkConstraint(c, f, a, m)
+    result = matchType(c, f, a, m)

 proc matchSym(c: PContext; candidate: PSym, n: PNode; m: var MatchCon): bool =
  ## Checks if 'candidate' matches 'n' from the concept body. 'n' is a nkProcDef
  ## or similar.

  # watch out: only add bindings after a completely successful match.
-  m.bindings = m.bindings.newTypeMapLayer()
+  let oldLen = m.inferred.len

  let can = candidate.typ.n
-  let con = defSignatureType(n).n
+  let con = n[0].sym.typ.n
+
  if can.len < con.len:
    # too few arguments, cannot be a match:
    return false
-  
-  if can.len > con.len:
-    # too many arguments (not optional)
-    for i in con.len ..< can.len:
-      if can[i].sym.ast == nil:
-        return false
-  
-  when defined(debugConcepts):
-    echo "considering: ", renderTree(candidate.procDefSignature), " ", candidate.magic
-  
+
  let common = min(can.len, con.len)
  for i in 1 ..< common:
-    if not checkConstraint(c, con[i].typ, can[i].typ, m):
-      m.bindings.setToPreviousLayer()
+    if not matchType(c, con[i].typ, can[i].typ, m):
+      m.inferred.setLen oldLen
      return false
-  
-  if not matchReturnType(c, n.defSignatureType.returnType, candidate.typ.returnType, m):
-    m.bindings.setToPreviousLayer()
+
+  if not matchReturnType(c, n[0].sym.typ[0], candidate.typ[0], m):
+    m.inferred.setLen oldLen
    return false

  # all other parameters have to be optional parameters:
@@ -476,7 +261,7 @@ proc matchSym(c: PContext; candidate: PSym, n: PNode; m: var MatchCon): bool =
    assert can[i].kind == nkSym
    if can[i].sym.ast == nil:
      # has too many arguments one of which is not optional:
-      m.bindings.setToPreviousLayer()
+      m.inferred.setLen oldLen
      return false

  return true
@@ -484,14 +269,12 @@ proc matchSym(c: PContext; candidate: PSym, n: PNode; m: var MatchCon): bool =
 proc matchSyms(c: PContext, n: PNode; kinds: set[TSymKind]; m: var MatchCon): bool =
  ## Walk the current scope, extract candidates which the same name as 'n[namePos]',
  ## 'n' is the nkProcDef or similar from the concept that we try to match.
-  result = false
-  var candidates = searchScopes(c, n[namePos].sym.name, kinds)
-  searchImportsAll(c, n[namePos].sym.name, kinds, candidates)
+  let candidates = searchInScopesAllCandidatesFilterBy(c, n[namePos].sym.name, kinds)
  for candidate in candidates:
+    #echo "considering ", typeToString(candidate.typ), " ", candidate.magic
    m.magic = candidate.magic
-    if matchSym(c, candidate, n, m):
-      result = true
-      break
+    if matchSym(c, candidate, n, m): return true
+  result = false

 proc conceptMatchNode(c: PContext; n: PNode; m: var MatchCon): bool =
  ## Traverse the concept's AST ('n') and see if every declaration inside 'n'
@@ -524,66 +307,35 @@ proc conceptMatchNode(c: PContext; n: PNode; m: var MatchCon): bool =
    # error was reported earlier.
    result = false

-proc fixBindings(bindings: var LayeredIdTable; concpt: PType; invocation: PType; m: var MatchCon) =
-  # invocation != nil means we have a non-atomic concept:
-  if invocation != nil and invocation.kind == tyGenericInvocation:
-    assert concpt.sym.typ.kind == tyGenericBody
-    
-    for i in 0 .. concpt.sym.typ.len - 1:
-      let thisSym = concpt.sym.typ[i]
-      if lookup(bindings, thisSym) != nil:
-        # dont trust the bindings over existing ones
-        continue
-      let found = m.bindings.lookup(thisSym)
-      if found != nil:
-        when logBindings: echo "Invocation bind: ", thisSym, " ", found
-        bindings.put(thisSym, found)
-    
-    # bind even more generic parameters
-    let genBody = invocation.base
-    assert genBody.kind == tyGenericBody
-    for i in FirstGenericParamAt ..< invocation.kidsLen:
-      let bpram = genBody[i - 1]
-      if lookup(bindings, invocation[i]) != nil:
-        # dont trust the bindings over existing ones
-        continue
-      let boundV = lookup(bindings, bpram)
-      when logBindings: echo "generic body bind: '", invocation[i], "' '", boundV, "'"
-      if boundV != nil:
-        bindings.put(invocation[i], boundV)
-  bindings.put(concpt, m.potentialImplementation)
-
-proc processConcept(c: PContext; concpt, invocation: PType, bindings: var LayeredIdTable; m: var MatchCon): bool =
-  m.bindings = m.bindings.newTypeMapLayer()
-  if invocation != nil and invocation.kind == tyGenericInst:
-    let genericBody = invocation.base
-    for i in 1..<invocation.kidsLen-1:
-      # instGenericContainer can bind `tyVoid`
-      if invocation[i].kind != tyVoid:
-        bindParam(c, m, genericBody[i-1], invocation[i])
-  result = conceptMatchNode(c, concpt.conceptBody, m)
-  if result and mfDontBind notin m.flags:
-    fixBindings(bindings, concpt, invocation, m)
-
-proc conceptMatch*(c: PContext; concpt, arg: PType; bindings: var LayeredIdTable; invocation: PType, flags: set[MatchFlags] = {}): bool =
+proc conceptMatch*(c: PContext; concpt, arg: PType; bindings: var TIdTable; invocation: PType): bool =
  ## Entry point from sigmatch. 'concpt' is the concept we try to match (here still a PType but
-  ## we extract its AST via 'concpt.n.lastSon'). 'arg' is the type that might fulfill the
+  ## we extract its AST via 'concpt.n.lastSon'). 'arg' is the type that might fullfill the
  ## concept's requirements. If so, we return true and fill the 'bindings' with pairs of
  ## (typeVar, instance) pairs. ('typeVar' is usually simply written as a generic 'T'.)
  ## 'invocation' can be nil for atomic concepts. For non-atomic concepts, it contains the
  ## `C[S, T]` parent type that we look for. We need this because we need to store bindings
  ## for 'S' and 'T' inside 'bindings' on a successful match. It is very important that
  ## we do not add any bindings at all on an unsuccessful match!
-  var m = MatchCon(bindings: bindings, potentialImplementation: arg, concpt: concpt, flags: flags)
-  if arg.isConcept:
-    result = conceptsMatch(c, concpt.reduceToBase, arg.reduceToBase, m) >= mkSubset
-  elif arg.acceptsAllTypes:
-    # XXX: I think this is wrong, or at least partially wrong. Can still test ambiguous types
-    result = false
-  elif mfCheckGeneric in m.flags:
-    # prioritize concepts the least. Specifically if the arg is not a catch all as per above
-    result = true
-  else:
-    result = processConcept(c, concpt, invocation, bindings, m)
-
-  
+  var m = MatchCon(inferred: @[], potentialImplementation: arg)
+  result = conceptMatchNode(c, concpt.n.lastSon, m)
+  if result:
+    for (a, b) in m.inferred:
+      if b.kind == tyGenericParam:
+        var dest = b
+        while true:
+          dest = existingBinding(m, dest)
+          if dest == nil or dest.kind != tyGenericParam: break
+        if dest != nil:
+          bindings.idTablePut(a, dest)
+          when logBindings: echo "A bind ", a, " ", dest
+      else:
+        bindings.idTablePut(a, b)
+        when logBindings: echo "B bind ", a, " ", b
+    # we have a match, so bind 'arg' itself to 'concpt':
+    bindings.idTablePut(concpt, arg)
+    # invocation != nil means we have a non-atomic concept:
+    if invocation != nil and arg.kind == tyGenericInst and invocation.len == arg.len-1:
+      # bind even more generic parameters
+      assert invocation.kind == tyGenericInvocation
+      for i in 1 ..< invocation.len:
+        bindings.idTablePut(invocation[i], arg[i])
--- a/compiler/condsyms.nim
+++ b/compiler/condsyms.nim
@@ -157,7 +157,6 @@ proc initDefines*(symbols: StringTableRef) =
  defineSymbol("nimAllowNonVarDestructor")
  defineSymbol("nimHasQuirky")
  defineSymbol("nimHasEnsureMove")
-  defineSymbol("nimHasNoReturnError")

  defineSymbol("nimUseStrictDefs")
  defineSymbol("nimHasNolineTooLong")
@@ -166,8 +165,4 @@ proc initDefines*(symbols: StringTableRef) =
  defineSymbol("nimHasWarnStdPrefix")

  defineSymbol("nimHasVtables")
-  defineSymbol("nimHasGenericsOpenSym2")
-  defineSymbol("nimHasGenericsOpenSym3")
-  defineSymbol("nimHasJsNoLambdaLifting")
-  defineSymbol("nimHasDefaultFloatRoundtrip")
-  defineSymbol("nimHasXorSet")
+  defineSymbol("nimHasSeqsV3")
--- a/compiler/dfa.nim
+++ b/compiler/dfa.nim
@@ -46,10 +46,10 @@ type
    case isTryBlock: bool
    of false:
      label: PSym
-      breakFixups: seq[(TPosition, seq[PNode])] # Contains the gotos for the breaks along with their pending finales
+      breakFixups: seq[(TPosition, seq[PNode])] #Contains the gotos for the breaks along with their pending finales
    of true:
      finale: PNode
-      raiseFixups: seq[TPosition] # Contains the gotos for the raises
+      raiseFixups: seq[TPosition] #Contains the gotos for the raises

  Con = object
    code: ControlFlowGraph
@@ -181,6 +181,14 @@ proc genIf(c: var Con, n: PNode) =
    goto Lend3
  L3:
    D
+    goto Lend3 # not eliminated to simplify the join generation
+  Lend3:
+    join F3
+  Lend2:
+    join F2
+  Lend:
+    join F1
+
  ]#
  var endings: seq[TPosition] = @[]
  let oldInteresting = c.interestingInstructions
@@ -205,6 +213,7 @@ proc genAndOr(c: var Con; n: PNode) =
  #   fork lab1
  #   asgn dest, b
  # lab1:
+  #   join F1
  c.gen(n[1])
  forkT:
    c.gen(n[2])
@@ -315,7 +324,7 @@ proc genRaise(c: var Con; n: PNode) =
      if c.blocks[i].isTryBlock:
        genBreakOrRaiseAux(c, i, n)
        return
-    assert false # Unreachable
+    assert false #Unreachable
  else:
    genNoReturn(c)

@@ -371,7 +380,7 @@ proc genCall(c: var Con; n: PNode) =
  if t != nil: t = t.skipTypes(abstractInst)
  for i in 1..<n.len:
    gen(c, n[i])
-    if t != nil and i < t.signatureLen and isOutParam(t[i]):
+    if t != nil and i < t.len and isOutParam(t[i]):
      # Pass by 'out' is a 'must def'. Good enough for a move optimizer.
      genDef(c, n[i])
  # every call can potentially raise:
@@ -381,6 +390,7 @@ proc genCall(c: var Con; n: PNode) =
    # fork lab1
    # goto exceptionHandler (except or finally)
    # lab1:
+    # join F1
    forkT:
      for i in countdown(c.blocks.high, 0):
        if c.blocks[i].isTryBlock:
@@ -439,8 +449,8 @@ proc gen(c: var Con; n: PNode) =
    genUse(c, n)
  of nkIfStmt, nkIfExpr: genIf(c, n)
  of nkWhenStmt:
-    # This is "when nimvm" node. Chose the second branch.
-    gen(c, n[1][0])
+    # This is "when nimvm" node. Chose the first branch.
+    gen(c, n[0][1])
  of nkCaseStmt: genCase(c, n)
  of nkWhileStmt: genWhile(c, n)
  of nkBlockExpr, nkBlockStmt: genBlock(c, n)
--- a/compiler/docgen.nim
+++ b/compiler/docgen.nim
@@ -115,7 +115,7 @@ proc add(dest: var ItemPre, str: string) = dest.add ItemFragment(isRst: false, s

 proc addRstFileIndex(d: PDoc, fileIndex: lineinfos.FileIndex): rstast.FileIndex =
  let invalid = rstast.FileIndex(-1)
-  result = d.nimToRstFid.getOrDefault(fileIndex, invalid)
+  result = d.nimToRstFid.getOrDefault(fileIndex, default = invalid)
  if result == invalid:
    let fname = toFullPath(d.conf, fileIndex)
    result = addFilename(d.sharedState, fname)
@@ -289,7 +289,7 @@ template declareClosures(currentFilename: AbsoluteFile, destFile: string) =
    let outDirPath: RelativeFile =
        presentationPath(conf, AbsoluteFile(basedir / targetRelPath))
          # use presentationPath because `..` path can be be mangled to `_._`
-    result = (string(conf.outDir / outDirPath), "")
+    result.targetPath = string(conf.outDir / outDirPath)
    if not fileExists(result.targetPath):
      # this can happen if targetRelPath goes to parent directory `OUTDIR/..`.
      # Trying it, this may cause ambiguities, but allows us to insert
@@ -830,8 +830,8 @@ proc getName(n: PNode): string =
  of nkAccQuoted:
    result = "`"
    for i in 0..<n.len: result.add(getName(n[i]))
-    result.add('`')
-  of nkOpenSymChoice, nkClosedSymChoice, nkOpenSym:
+    result = "`"
+  of nkOpenSymChoice, nkClosedSymChoice:
    result = getName(n[0])
  else:
    result = ""
@@ -849,7 +849,7 @@ proc getNameIdent(cache: IdentCache; n: PNode): PIdent =
    var r = ""
    for i in 0..<n.len: r.add(getNameIdent(cache, n[i]).s)
    result = getIdent(cache, r)
-  of nkOpenSymChoice, nkClosedSymChoice, nkOpenSym:
+  of nkOpenSymChoice, nkClosedSymChoice:
    result = getNameIdent(cache, n[0])
  else:
    result = nil
@@ -863,7 +863,7 @@ proc getRstName(n: PNode): PRstNode =
  of nkAccQuoted:
    result = getRstName(n[0])
    for i in 1..<n.len: result.text.add(getRstName(n[i]).text)
-  of nkOpenSymChoice, nkClosedSymChoice, nkOpenSym:
+  of nkOpenSymChoice, nkClosedSymChoice:
    result = getRstName(n[0])
  else:
    result = nil
@@ -1000,9 +1000,8 @@ proc getTypeKind(n: PNode): string =
 proc toLangSymbol(k: TSymKind, n: PNode, baseName: string): LangSymbol =
  ## Converts symbol info (names/types/parameters) in `n` into format
  ## `LangSymbol` convenient for ``rst.nim``/``dochelpers.nim``.
-  result = LangSymbol(name: baseName.nimIdentNormalize,
-      symKind: k.toHumanStr
-  )
+  result.name = baseName.nimIdentNormalize
+  result.symKind = k.toHumanStr
  if k in routineKinds:
    var
      paramTypes: seq[string] = @[]
@@ -1031,7 +1030,7 @@ proc toLangSymbol(k: TSymKind, n: PNode, baseName: string): LangSymbol =
    if genNode != nil:
      var literal = ""
      var r: TSrcGen = initTokRender(genNode, {renderNoBody, renderNoComments,
-        renderNoPragmas, renderNoProcDefs, renderExpandUsing, renderNoPostfix})
+        renderNoPragmas, renderNoProcDefs, renderExpandUsing})
      var kind = tkEof
      while true:
        getNextTok(r, kind, literal)
@@ -1059,7 +1058,7 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx

  # Obtain the plain rendered string for hyperlink titles.
  var r: TSrcGen = initTokRender(n, {renderNoBody, renderNoComments, renderDocComments,
-    renderNoPragmas, renderNoProcDefs, renderExpandUsing, renderNoPostfix})
+    renderNoPragmas, renderNoProcDefs, renderExpandUsing})
  while true:
    getNextTok(r, kind, literal)
    if kind == tkEof:
@@ -1086,9 +1085,6 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
    symbolOrIdEnc = encodeUrl(symbolOrId, usePlus = false)
    deprecationMsg = genDeprecationMsg(d, pragmaNode)
    rstLangSymbol = toLangSymbol(k, n, cleanPlainSymbol)
-    symNameNode =
-      if nameNode.kind == nkPostfix: nameNode[1]
-      else: nameNode

  # we generate anchors automatically for subsequent use in doc comments
  let lineinfo = rstast.TLineInfo(
@@ -1099,10 +1095,10 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
               priority = symbolPriority(k), info = lineinfo,
               module = addRstFileIndex(d, FileIndex d.module.position))

-  var renderFlags = {renderNoBody, renderNoComments, renderDocComments,
-    renderSyms, renderExpandUsing, renderNoPostfix}
-  if nonExports:
-    renderFlags.incl renderNonExportedFields
+  let renderFlags =
+    if nonExports: {renderNoBody, renderNoComments, renderDocComments, renderSyms,
+      renderExpandUsing, renderNonExportedFields}
+    else: {renderNoBody, renderNoComments, renderDocComments, renderSyms, renderExpandUsing}
  nodeToHighlightedHtml(d, n, result, renderFlags, symbolOrIdEnc)

  let seeSrc = genSeeSrc(d, toFullPath(d.conf, n.info), n.info.line.int)
@@ -1125,19 +1121,18 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
  let external = d.destFile.AbsoluteFile.relativeTo(d.conf.outDir, '/').changeFileExt(HtmlExt).string

  var attype = ""
-  if k in routineKinds and symNameNode.kind == nkSym:
+  if k in routineKinds and nameNode.kind == nkSym:
    let att = attachToType(d, nameNode.sym)
    if att != nil:
      attype = esc(d.target, att.name.s)
-  elif k == skType and symNameNode.kind == nkSym and
-      symNameNode.sym.typ.kind in {tyEnum, tyBool}:
-    let etyp = symNameNode.sym.typ
+  elif k == skType and nameNode.kind == nkSym and nameNode.sym.typ.kind in {tyEnum, tyBool}:
+    let etyp = nameNode.sym.typ
    for e in etyp.n:
      if e.sym.kind != skEnumField: continue
      let plain = renderPlainSymbolName(e)
      let symbolOrId = d.newUniquePlainSymbol(plain)
      setIndexTerm(d[], ieNim, htmlFile = external, id = symbolOrId,
-                   term = plain, linkTitle = symNameNode.sym.name.s & '.' & plain,
+                   term = plain, linkTitle = nameNode.sym.name.s & '.' & plain,
                   linkDesc = xmltree.escape(getPlainDocstring(e).docstringSummary),
                   line = n.info.line.int)

@@ -1158,8 +1153,8 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
               linkTitle = detailedName,
               linkDesc = xmltree.escape(plainDocstring.docstringSummary),
               line = n.info.line.int)
-  if k == skType and symNameNode.kind == nkSym:
-    d.types.strTableAdd symNameNode.sym
+  if k == skType and nameNode.kind == nkSym:
+    d.types.strTableAdd nameNode.sym

 proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false): JsonItem =
  if not isVisible(d, nameNode): return
@@ -1167,14 +1162,12 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
    name = getNameEsc(d, nameNode)
    comm = genRecComment(d, n)
    r: TSrcGen
-    renderFlags = {renderNoBody, renderNoComments, renderDocComments,
-      renderExpandUsing, renderNoPostfix}
+    renderFlags = {renderNoBody, renderNoComments, renderDocComments, renderExpandUsing}
  if nonExports:
    renderFlags.incl renderNonExportedFields
  r = initTokRender(n, renderFlags)
-  result = JsonItem(json: %{ "name": %name, "type": %($k), "line": %n.info.line.int,
+  result.json = %{ "name": %name, "type": %($k), "line": %n.info.line.int,
                   "col": %n.info.col}
-  )
  if comm != nil:
    result.rst = comm
    result.rstField = "description"
@@ -1206,7 +1199,8 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
        var param = %{"name": %($genericParam)}
        if genericParam.sym.typ.len > 0:
          param["types"] = newJArray()
-          param["types"] = %($genericParam.sym.typ.elementType)
+        for kind in genericParam.sym.typ:
+          param["types"].add %($kind)
        result.json["signature"]["genericParams"].add param
  if optGenIndex in d.conf.globalOptions:
    genItem(d, n, nameNode, k, kForceExport)
@@ -1320,7 +1314,7 @@ proc documentEffect(cache: IdentCache; n, x: PNode, effectType: TSpecialWord, id
      if t.startsWith("ref "): t = substr(t, 4)
      effects[i] = newIdentNode(getIdent(cache, t), n.info)
      # set the type so that the following analysis doesn't screw up:
-      effects[i].typ() = real[i].typ
+      effects[i].typ = real[i].typ

    result = newTreeI(nkExprColonExpr, n.info,
      newIdentNode(getIdent(cache, $effectType), n.info), effects)
@@ -1407,13 +1401,9 @@ proc generateDoc*(d: PDoc, n, orig: PNode, config: ConfigRef, docFlags: DocFlags
  of nkExportStmt:
    for it in n:
      if it.kind == nkSym:
-        if d.module != nil and d.module == it.sym.owner:  # in current module
-          # bug #23051; don't generate documentation for exported symbols again
-          if sfExported notin it.sym.flags:
-            generateDoc(d, it.sym.ast, orig, config, kForceExport)
-          # else it's to be handled in `of XxxSection` branch
+        if d.module != nil and d.module == it.sym.owner:
+          generateDoc(d, it.sym.ast, orig, config, kForceExport)
        elif it.sym.ast != nil:
-          # only export symbols in imported modules, not in current module
          exportSym(d, it.sym)
  of nkExportExceptStmt: discard "transformed into nkExportStmt by semExportExcept"
  of nkFromStmt, nkImportExceptStmt: traceDeps(d, n[0])
--- a/compiler/enumtostr.nim
+++ b/compiler/enumtostr.nim
@@ -33,10 +33,6 @@ proc genEnumToStrProc*(t: PType; info: TLineInfo; g: ModuleGraph; idgen: IdGener
    caseStmt.add newTree(nkOfBranch, newIntTypeNode(field.position, t),
      newTree(nkStmtList, newTree(nkFastAsgn, newSymNode(res), newStrNode(val, info))))
    #newIntTypeNode(nkIntLit, field.position, t)
-  # safety branch for invalid data:
-  caseStmt.add newTree(nkElse,
-    newTree(nkStmtList, newTree(nkFastAsgn, newSymNode(res),
-      newStrNode("", info))))

  body.add(caseStmt)

@@ -67,8 +63,8 @@ proc searchObjCaseImpl(obj: PNode; field: PSym): PNode =

 proc searchObjCase(t: PType; field: PSym): PNode =
  result = searchObjCaseImpl(t.n, field)
-  if result == nil and t.baseClass != nil:
-    result = searchObjCase(t.baseClass.skipTypes({tyAlias, tyGenericInst, tyRef, tyPtr}), field)
+  if result == nil and t.len > 0:
+    result = searchObjCase(t[0].skipTypes({tyAlias, tyGenericInst, tyRef, tyPtr}), field)
  doAssert result != nil

 proc genCaseObjDiscMapping*(t: PType; field: PSym; info: TLineInfo; g: ModuleGraph; idgen: IdGenerator): PSym =
--- a/compiler/evalffi.nim
+++ b/compiler/evalffi.nim
@@ -99,7 +99,7 @@ proc mapType(conf: ConfigRef, t: ast.PType): ptr libffi.Type =
     tyTyped, tyTypeDesc, tyProc, tyArray, tyStatic, tyNil:
    result = addr libffi.type_pointer
  of tyDistinct, tyAlias, tySink:
-    result = mapType(conf, t.skipModifier)
+    result = mapType(conf, t[0])
  else:
    result = nil
  # too risky:
@@ -126,16 +126,16 @@ proc packSize(conf: ConfigRef, v: PNode, typ: PType): int =
    if v.kind in {nkNilLit, nkPtrLit}:
      result = sizeof(pointer)
    else:
-      result = sizeof(pointer) + packSize(conf, v[0], typ.elementType)
+      result = sizeof(pointer) + packSize(conf, v[0], typ.lastSon)
  of tyDistinct, tyGenericInst, tyAlias, tySink:
-    result = packSize(conf, v, typ.skipModifier)
+    result = packSize(conf, v, typ[0])
  of tyArray:
    # consider: ptr array[0..1000_000, int] which is common for interfacing;
    # we use the real length here instead
    if v.kind in {nkNilLit, nkPtrLit}:
      result = sizeof(pointer)
    elif v.len != 0:
-      result = v.len * packSize(conf, v[0], typ.elementType)
+      result = v.len * packSize(conf, v[0], typ[1])
    else:
      result = 0
  else:
@@ -234,19 +234,19 @@ proc pack(conf: ConfigRef, v: PNode, typ: PType, res: pointer) =
        packRecCheck = 0
        globalError(conf, v.info, "cannot map value to FFI " & typeToString(v.typ))
      inc packRecCheck
-      pack(conf, v[0], typ.elementType, res +! sizeof(pointer))
+      pack(conf, v[0], typ.lastSon, res +! sizeof(pointer))
      dec packRecCheck
      awr(pointer, res +! sizeof(pointer))
  of tyArray:
-    let baseSize = getSize(conf, typ.elementType)
+    let baseSize = getSize(conf, typ[1])
    for i in 0..<v.len:
-      pack(conf, v[i], typ.elementType, res +! i * baseSize)
+      pack(conf, v[i], typ[1], res +! i * baseSize)
  of tyObject, tyTuple:
    packObject(conf, v, typ, res)
  of tyNil:
    discard
  of tyDistinct, tyGenericInst, tyAlias, tySink:
-    pack(conf, v, typ.skipModifier, res)
+    pack(conf, v, typ[0], res)
  else:
    globalError(conf, v.info, "cannot map value to FFI " & typeToString(v.typ))

@@ -275,7 +275,7 @@ proc unpackObject(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
  # the nkPar node:
  if n.isNil:
    result = newNode(nkTupleConstr)
-    result.typ() = typ
+    result.typ = typ
    if typ.n.isNil:
      internalError(conf, "cannot unpack unnamed tuple")
    unpackObjectAdd(conf, x, typ.n, result)
@@ -298,15 +298,15 @@ proc unpackObject(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
 proc unpackArray(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
  if n.isNil:
    result = newNode(nkBracket)
-    result.typ() = typ
+    result.typ = typ
    newSeq(result.sons, lengthOrd(conf, typ).toInt)
  else:
    result = n
    if result.kind != nkBracket:
      globalError(conf, n.info, "cannot map value from FFI")
-  let baseSize = getSize(conf, typ.elementType)
+  let baseSize = getSize(conf, typ[1])
  for i in 0..<result.len:
-    result[i] = unpack(conf, x +! i * baseSize, typ.elementType, result[i])
+    result[i] = unpack(conf, x +! i * baseSize, typ[1], result[i])

 proc canonNodeKind(k: TNodeKind): TNodeKind =
  case k
@@ -319,7 +319,7 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
  template aw(k, v, field: untyped): untyped =
    if n.isNil:
      result = newNode(k)
-      result.typ() = typ
+      result.typ = typ
    else:
      # check we have the right field:
      result = n
@@ -333,12 +333,12 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
  template setNil() =
    if n.isNil:
      result = newNode(nkNilLit)
-      result.typ() = typ
+      result.typ = typ
    else:
      reset n[]
      result = n
      result[] = TNode(kind: nkNilLit)
-      result.typ() = typ
+      result.typ = typ

  template awi(kind, v: untyped): untyped = aw(kind, v, intVal)
  template awf(kind, v: untyped): untyped = aw(kind, v, floatVal)
@@ -387,7 +387,7 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
      awi(nkPtrLit, cast[int](p))
    elif n != nil and n.len == 1:
      internalAssert(conf, n.kind == nkRefTy)
-      n[0] = unpack(conf, p, typ.elementType, n[0])
+      n[0] = unpack(conf, p, typ.lastSon, n[0])
      result = n
    else:
      result = nil
@@ -405,7 +405,7 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
  of tyNil:
    setNil()
  of tyDistinct, tyGenericInst, tyAlias, tySink:
-    result = unpack(conf, x, typ.skipModifier, n)
+    result = unpack(conf, x, typ.lastSon, n)
  else:
    # XXX what to do with 'array' here?
    result = nil
@@ -427,14 +427,14 @@ proc fficast*(conf: ConfigRef, x: PNode, destTyp: PType): PNode =
    # cast through a pointer needs a new inner object:
    let y = if x.kind == nkRefTy: newNodeI(nkRefTy, x.info, 1)
            else: x.copyTree
-    y.typ() = x.typ
+    y.typ = x.typ
    result = unpack(conf, a, destTyp, y)
    dealloc a

 proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =
  internalAssert conf, call[0].kind == nkPtrLit

-  var cif: TCif = default(TCif)
+  var cif: TCif
  var sig: ParamList = default(ParamList)
  # use the arguments' types for varargs support:
  for i in 1..<call.len:
@@ -444,7 +444,7 @@ proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =

  let typ = call[0].typ
  if prep_cif(cif, mapCallConv(conf, typ.callConv, call.info), cuint(call.len-1),
-              mapType(conf, typ.returnType), sig) != OK:
+              mapType(conf, typ[0]), sig) != OK:
    globalError(conf, call.info, "error in FFI call")

  var args: ArgList = default(ArgList)
@@ -453,15 +453,15 @@ proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =
    var t = call[i].typ
    args[i-1] = alloc0(packSize(conf, call[i], t))
    pack(conf, call[i], t, args[i-1])
-  let retVal = if isEmptyType(typ.returnType): pointer(nil)
-               else: alloc(getSize(conf, typ.returnType).int)
+  let retVal = if isEmptyType(typ[0]): pointer(nil)
+               else: alloc(getSize(conf, typ[0]).int)

  libffi.call(cif, fn, retVal, args)

  if retVal.isNil:
    result = newNode(nkEmpty)
  else:
-    result = unpack(conf, retVal, typ.returnType, nil)
+    result = unpack(conf, retVal, typ[0], nil)
    result.info = call.info

  if retVal != nil: dealloc retVal
@@ -474,14 +474,14 @@ proc callForeignFunction*(conf: ConfigRef, fn: PNode, fntyp: PType,
                          info: TLineInfo): PNode =
  internalAssert conf, fn.kind == nkPtrLit

-  var cif: TCif = default(TCif)
+  var cif: TCif
  var sig: ParamList = default(ParamList)
  for i in 0..len-1:
    var aTyp = args[i+start].typ
    if aTyp.isNil:
      internalAssert conf, i+1 < fntyp.len
      aTyp = fntyp[i+1]
-      args[i+start].typ() = aTyp
+      args[i+start].typ = aTyp
    sig[i] = mapType(conf, aTyp)
    if sig[i].isNil: globalError(conf, info, "cannot map FFI type")

--- a/compiler/evaltempl.nim
+++ b/compiler/evaltempl.nim
@@ -17,8 +17,8 @@ type
    owner, genSymOwner: PSym
    instLines: bool   # use the instantiation lines numbers
    isDeclarative: bool
-    mapping: SymMapping # every gensym'ed symbol needs to be mapped to some
-                        # new symbol
+    mapping: TIdTable # every gensym'ed symbol needs to be mapped to some
+                      # new symbol
    config: ConfigRef
    ic: IdentCache
    instID: int
@@ -33,19 +33,6 @@ proc evalTemplateAux(templ, actual: PNode, c: var TemplCtx, result: PNode) =
    let x = param
    if x.kind == nkArgList:
      for y in items(x): result.add(y)
-    elif nfDefaultRefsParam in x.flags:
-      # value of default param needs to be evaluated like template body
-      # if it contains other template params
-      var res: PNode
-      if isAtom(x):
-        res = newNodeI(nkPar, x.info)
-        evalTemplateAux(x, actual, c, res)
-        if res.len == 1: res = res[0]
-      else:
-        res = copyNode(x)
-        for i in 0..<x.safeLen:
-          evalTemplateAux(x[i], actual, c, res)
-      result.add res
    else:
      result.add copyTree(x)

@@ -57,19 +44,18 @@ proc evalTemplateAux(templ, actual: PNode, c: var TemplCtx, result: PNode) =
        handleParam actual[s.position]
      elif (s.owner != nil) and (s.kind == skGenericParam or
           s.kind == skType and s.typ != nil and s.typ.kind == tyGenericParam):
-        handleParam actual[s.owner.typ.signatureLen + s.position - 1]
+        handleParam actual[s.owner.typ.len + s.position - 1]
      else:
        internalAssert c.config, sfGenSym in s.flags or s.kind == skType
-        var x = idTableGet(c.mapping, s)
+        var x = PSym(idTableGet(c.mapping, s))
        if x == nil:
          x = copySym(s, c.idgen)
          # sem'check needs to set the owner properly later, see bug #9476
-          setOwner(x, nil) # c.genSymOwner
+          x.owner = nil # c.genSymOwner
          #if x.kind == skParam and x.owner.kind == skModule:
          #  internalAssert c.config, false
          idTablePut(c.mapping, s, x)
        if sfGenSym in s.flags:
-          # TODO: getIdent(c.ic, "`" & x.name.s & "`gensym" & $c.instID)
          result.add newIdentNode(getIdent(c.ic, x.name.s & "`gensym" & $c.instID),
            if c.instLines: actual.info else: templ.info)
        else:
@@ -130,7 +116,7 @@ proc evalTemplateArgs(n: PNode, s: PSym; conf: ConfigRef; fromHlo: bool): PNode
    # now that we have working untyped parameters.
    genericParams = if fromHlo: 0
                    else: s.ast[genericParamsPos].len
-    expectedRegularParams = s.typ.paramsLen
+    expectedRegularParams = s.typ.len-1
    givenRegularParams = totalParams - genericParams
  if givenRegularParams < 0: givenRegularParams = 0

@@ -182,7 +168,7 @@ proc wrapInComesFrom*(info: TLineInfo; sym: PSym; res: PNode): PNode =
    d.add newSymNode(sym, info)
    result.add d
    result.add res
-    result.typ() = res.typ
+    result.typ = res.typ

 proc evalTemplate*(n: PNode, tmpl, genSymOwner: PSym;
                   conf: ConfigRef;
@@ -196,14 +182,14 @@ proc evalTemplate*(n: PNode, tmpl, genSymOwner: PSym;

  # replace each param by the corresponding node:
  var args = evalTemplateArgs(n, tmpl, conf, fromHlo)
-  var ctx = TemplCtx(owner: tmpl,
-    genSymOwner: genSymOwner,
-    config: conf,
-    ic: ic,
-    mapping: initSymMapping(),
-    instID: instID[],
-    idgen: idgen
-  )
+  var ctx: TemplCtx
+  ctx.owner = tmpl
+  ctx.genSymOwner = genSymOwner
+  ctx.config = conf
+  ctx.ic = ic
+  ctx.mapping = initIdTable()
+  ctx.instID = instID[]
+  ctx.idgen = idgen

  let body = tmpl.ast[bodyPos]
  #echo "instantion of ", renderTree(body, {renderIds})
--- a/compiler/expanddefaults.nim
+++ b/compiler/expanddefaults.nim
@@ -55,8 +55,8 @@ proc expandDefaultN(n: PNode; info: TLineInfo; res: PNode) =
    discard

 proc expandDefaultObj(t: PType; info: TLineInfo; res: PNode) =
-  if t.baseClass != nil:
-    expandDefaultObj(t.baseClass, info, res)
+  if t[0] != nil:
+    expandDefaultObj(t[0], info, res)
  expandDefaultN(t.n, info, res)

 proc expandDefault(t: PType; info: TLineInfo): PNode =
@@ -82,13 +82,13 @@ proc expandDefault(t: PType; info: TLineInfo): PNode =
    result = newZero(t, info, nkIntLit)
  of tyRange:
    # Could use low(T) here to finally fix old language quirks
-    result = expandDefault(skipModifier t, info)
+    result = expandDefault(t[0], info)
  of tyVoid: result = newZero(t, info, nkEmpty)
  of tySink, tyGenericInst, tyDistinct, tyAlias, tyOwned:
-    result = expandDefault(t.skipModifier, info)
+    result = expandDefault(t.lastSon, info)
  of tyOrdinal, tyGenericBody, tyGenericParam, tyInferred, tyStatic:
-    if t.hasElementType:
-      result = expandDefault(t.skipModifier, info)
+    if t.len > 0:
+      result = expandDefault(t.lastSon, info)
    else:
      result = newZero(t, info, nkEmpty)
  of tyFromExpr:
@@ -100,16 +100,16 @@ proc expandDefault(t: PType; info: TLineInfo): PNode =
    result = newZero(t, info, nkBracket)
    let n = toInt64(lengthOrd(nil, t))
    for i in 0..<n:
-      result.add expandDefault(t.elementType, info)
+      result.add expandDefault(t[1], info)
  of tyPtr, tyRef, tyProc, tyPointer, tyCstring:
    result = newZero(t, info, nkNilLit)
  of tyVar, tyLent:
-    let e = t.elementType
+    let e = t.lastSon
    if e.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
      # skip the modifier, `var openArray` is a (ptr, len) pair too:
      result = expandDefault(e, info)
    else:
-      result = newZero(e, info, nkNilLit)
+      result = newZero(t.lastSon, info, nkNilLit)
  of tySet:
    result = newZero(t, info, nkCurly)
  of tyObject:
@@ -118,14 +118,14 @@ proc expandDefault(t: PType; info: TLineInfo): PNode =
    expandDefaultObj(t, info, result)
  of tyTuple:
    result = newZero(t, info, nkTupleConstr)
-    for it in t.kids:
+    for it in t:
      result.add expandDefault(it, info)
  of tyVarargs, tyOpenArray, tySequence, tyUncheckedArray:
    result = newZero(t, info, nkBracket)
  of tyString:
    result = newZero(t, info, nkStrLit)
  of tyNone, tyEmpty, tyUntyped, tyTyped, tyTypeDesc,
-     tyNil, tyGenericInvocation, tyError, tyBuiltInTypeClass,
+     tyNil, tyGenericInvocation, tyProxy, tyBuiltInTypeClass,
     tyUserTypeClass, tyUserTypeClassInst, tyCompositeTypeClass,
     tyAnd, tyOr, tyNot, tyAnything, tyConcept, tyIterable, tyForward:
    result = newZero(t, info, nkEmpty) # bug indicator
--- a/compiler/extccomp.nim
+++ b/compiler/extccomp.nim
@@ -19,7 +19,7 @@ import std/[os, osproc, streams, sequtils, times, strtabs, json, jsonutils, suga
 import std / strutils except addf

 when defined(nimPreviewSlimSystem):
-  import std/[syncio, assertions]
+  import std/syncio

 import ../dist/checksums/src/checksums/sha1

@@ -63,7 +63,7 @@ type

 # Configuration settings for various compilers.
 # When adding new compilers, the cmake sources could be a good reference:
-# https://cmake.org/gitweb?p=cmake.git;a=tree;f=Modules/Platform;
+# http://cmake.org/gitweb?p=cmake.git;a=tree;f=Modules/Platform;

 template compiler(name, settings: untyped): untyped =
  proc name: TInfoCC {.compileTime.} = settings
@@ -162,11 +162,7 @@ compiler vcc:
    linkerExe: "cl",
    linkTmpl: "$builddll$vccplatform /Fe$exefile $objfiles $buildgui /nologo $options",
    includeCmd: " /I",
-    # HACK: we call `cl` so we have to pass `/link` for linker options,
-    # but users may still want to pass arguments to `cl` (see #14221)
-    # to deal with this, we add `/link` before each `/LIBPATH`,
-    # the linker ignores extra `/link`s since it's an unrecognized argument
-    linkDirCmd: " /link /LIBPATH:",
+    linkDirCmd: " /LIBPATH:",
    linkLibCmd: " $1.lib",
    debug: " /RTC1 /Z7 ",
    pic: "",
@@ -176,22 +172,6 @@ compiler vcc:
    cppXsupport: "",
    props: {hasCpp, hasAssume, hasDeclspec})

-# Nvidia CUDA NVCC Compiler
-compiler nvcc:
-  result = gcc()
-  result.name = "nvcc"
-  result.compilerExe = "nvcc"
-  result.cppCompiler = "nvcc"
-  result.compileTmpl = "-c -x cu -Xcompiler=\"$options\" $include -o $objfile $file"
-  result.linkTmpl = "$buildgui $builddll -o $exefile $objfiles -Xcompiler=\"$options\""
-
-# AMD HIPCC Compiler (rocm/cuda)
-compiler hipcc:
-  result = clang()
-  result.name = "hipcc"
-  result.compilerExe = "hipcc"
-  result.cppCompiler = "hipcc"
-
 compiler clangcl:
  result = vcc()
  result.name = "clang_cl"
@@ -257,8 +237,8 @@ compiler tcc:
    linkerExe: "tcc",
    linkTmpl: "-o $exefile $options $buildgui $builddll $objfiles",
    includeCmd: " -I",
-    linkDirCmd: " -L",
-    linkLibCmd: " -l$1",
+    linkDirCmd: "", # XXX: not supported yet
+    linkLibCmd: "", # XXX: not supported yet
    debug: " -g ",
    pic: "",
    asmStmtFrmt: "asm($1);$n",
@@ -305,9 +285,7 @@ const
    envcc(),
    icl(),
    icc(),
-    clangcl(),
-    hipcc(),
-    nvcc()]
+    clangcl()]

  hExt* = ".h"

@@ -341,7 +319,7 @@ proc getConfigVar(conf: ConfigRef; c: TSystemCC, suffix: string): string =
  var fullSuffix = suffix
  case conf.backend
  of backendCpp, backendJs, backendObjc: fullSuffix = "." & $conf.backend & suffix
-  of backendC: discard
+  of backendC, backendNir: discard
  of backendInvalid:
    # during parsing of cfg files; we don't know the backend yet, no point in
    # guessing wrong thing
@@ -474,11 +452,6 @@ proc noAbsolutePaths(conf: ConfigRef): bool {.inline.} =
 proc cFileSpecificOptions(conf: ConfigRef; nimname, fullNimFile: string): string =
  result = conf.compileOptions

-  if (conf.cCompiler == ccGcc or conf.cCompiler == ccCLang) and
-       conf.selectedGC == gcRefc:
-    # bug #10625
-    addOpt(result, "-fno-omit-frame-pointer")
-
  for option in conf.compileOptionsCmd:
    if strutils.find(result, option, 0) < 0:
      addOpt(result, option)
@@ -786,7 +759,7 @@ proc getLinkCmd(conf: ConfigRef; output: AbsoluteFile,
    # https://blog.molecular-matters.com/2017/05/09/deleting-pdb-files-locked-by-visual-studio/
    # and a bit about the .pdb format in case that is ever needed:
    # https://github.com/crosire/blink
-    # https://www.debuginfo.com/articles/debuginfomatch.html#pdbfiles
+    # http://www.debuginfo.com/articles/debuginfomatch.html#pdbfiles
    if conf.hcrOn and isVSCompatible(conf):
      let t = now()
      let pdb = output.string & "." & format(t, "MMMM-yyyy-HH-mm-") & $t.nanosecond & ".pdb"
@@ -1009,11 +982,10 @@ proc jsonBuildInstructionsFile*(conf: ConfigRef): AbsoluteFile =
  # works out of the box with `hashMainCompilationParams`.
  result = getNimcacheDir(conf) / conf.outFile.changeFileExt("json")

-const cacheVersion = "D20240927T193831" # update when `BuildCache` spec changes
+const cacheVersion = "D20210525T193831" # update when `BuildCache` spec changes
 type BuildCache = object
  cacheVersion: string
  outputFile: string
-  outputLastModificationTime: string
  compile: seq[(string, string)]
  link: seq[string]
  linkcmd: string
@@ -1027,7 +999,7 @@ type BuildCache = object
  depfiles: seq[(string, string)]
  nimexe: string

-proc writeJsonBuildInstructions*(conf: ConfigRef; deps: StringTableRef) =
+proc writeJsonBuildInstructions*(conf: ConfigRef) =
  var linkFiles = collect(for it in conf.externalToLink:
    var it = it
    if conf.noAbsolutePaths: it = it.extractFilename
@@ -1048,17 +1020,11 @@ proc writeJsonBuildInstructions*(conf: ConfigRef; deps: StringTableRef) =
    currentDir: getCurrentDir())
  if optRun in conf.globalOptions or isDefined(conf, "nimBetterRun"):
    bcache.cmdline = conf.commandLine
-    for it in conf.m.fileInfos:
+    bcache.depfiles = collect(for it in conf.m.fileInfos:
      let path = it.fullPath.string
      if isAbsolute(path): # TODO: else?
-        if path in deps:
-          bcache.depfiles.add (path, deps[path])
-        else: # backup for configs etc.
-          bcache.depfiles.add (path, $secureHashFile(path))
-
+        (path, $secureHashFile(path)))
    bcache.nimexe = hashNimExe()
-    if fileExists(bcache.outputFile):
-      bcache.outputLastModificationTime = $getLastModificationTime(bcache.outputFile)
  conf.jsonBuildFile = conf.jsonBuildInstructionsFile
  conf.jsonBuildFile.string.writeFile(bcache.toJson.pretty)

@@ -1079,8 +1045,6 @@ proc changeDetectedViaJsonBuildInstructions*(conf: ConfigRef; jsonFile: Absolute
    # xxx optimize by returning false if stdin input was the same
  for (file, hash) in bcache.depfiles:
    if $secureHashFile(file) != hash: return true
-  if bcache.outputLastModificationTime != $getLastModificationTime(bcache.outputFile):
-    return true

 proc runJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile) =
  var bcache: BuildCache = default(BuildCache)
@@ -1097,7 +1061,7 @@ proc runJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile) =
      "jsonscript command outputFile '$1' must match '$2' which was specified during --compileOnly, see \"outputFile\" entry in '$3' " %
      [outputCurrent, output, jsonFile.string])
  var cmds: TStringSeq = default(TStringSeq)
-  var prettyCmds: TStringSeq = default(TStringSeq)
+  var prettyCmds: TStringSeq= default(TStringSeq)
  let prettyCb = proc (idx: int) = writePrettyCmdsStderr(prettyCmds[idx])
  for (name, cmd) in bcache.compile:
    cmds.add cmd
--- a/compiler/guards.nim
+++ b/compiler/guards.nim
@@ -1063,7 +1063,7 @@ proc pleViaModel(model: TModel; aa, bb: PNode): TImplication =
      let b = fact[2]
      if a.kind == nkSym: replacements.add((a,b))
      else: replacements.add((b,a))
-  var m = TModel()
+  var m: TModel
  var a = aa
  var b = bb
  if replacements.len > 0:
@@ -1104,7 +1104,7 @@ proc settype(n: PNode): PType =

 proc buildOf(it, loc: PNode; o: Operators): PNode =
  var s = newNodeI(nkCurly, it.info, it.len-1)
-  s.typ() = settype(loc)
+  s.typ = settype(loc)
  for i in 0..<it.len-1: s[i] = it[i]
  result = newNodeI(nkCall, it.info, 3)
  result[0] = newSymNode(o.opContains)
@@ -1165,12 +1165,8 @@ proc buildProperFieldCheck(access, check: PNode; o: Operators): PNode =
  if check[1].kind == nkCurly:
    result = copyTree(check)
    if access.kind == nkDotExpr:
-      # change the access to the discriminator field access
      var a = copyTree(access)
-      # set field name to discriminator field name
      a[1] = check[2]
-      # set discriminator field type: important for `neg`
-      a.typ() = check[2].typ
      result[2] = a
      # 'access.kind != nkDotExpr' can happen for object constructors
      # which we don't check yet
--- a/compiler/ic/ic.nim
+++ b/compiler/ic/ic.nim
@@ -16,7 +16,7 @@ from std/os import removeFile, isAbsolute

 import ../../dist/checksums/src/checksums/sha1

-import iclineinfos
+import ".." / nir / nirlineinfos

 when defined(nimPreviewSlimSystem):
  import std/[syncio, assertions, formatfloat]
@@ -59,8 +59,8 @@ type
    emittedTypeInfo*: seq[string]
    backendFlags*: set[ModuleBackendFlag]

-    syms*: OrderedTable[int32, PackedSym]
-    types*: OrderedTable[int32, PackedType]
+    syms*: seq[PackedSym]
+    types*: seq[PackedType]
    strings*: BiTable[string] # we could share these between modules.
    numbers*: BiTable[BiggestInt] # we also store floats in here so
                                  # that we can assure that every bit is kept
@@ -362,15 +362,15 @@ proc storeType(t: PType; c: var PackedEncoder; m: var PackedModule): PackedItemI
  result = PackedItemId(module: toLitId(t.uniqueId.module.FileIndex, c, m), item: t.uniqueId.item)

  if t.uniqueId.module == c.thisModule and not c.typeMarker.containsOrIncl(t.uniqueId.item):
-    #if t.uniqueId.item >= m.types.len:
-    #  setLen m.types, t.uniqueId.item+1
+    if t.uniqueId.item >= m.types.len:
+      setLen m.types, t.uniqueId.item+1

-    var p = PackedType(id: t.uniqueId.item, kind: t.kind, flags: t.flags, callConv: t.callConv,
+    var p = PackedType(kind: t.kind, flags: t.flags, callConv: t.callConv,
      size: t.size, align: t.align, nonUniqueId: t.itemId.item,
      paddingAtEnd: t.paddingAtEnd)
    storeNode(p, t, n)
    p.typeInst = t.typeInst.storeType(c, m)
-    for kid in kids t:
+    for kid in items t:
      p.types.add kid.storeType(c, m)
    c.addMissing t.sym
    p.sym = t.sym.safeItemId(c, m)
@@ -383,9 +383,10 @@ proc storeType(t: PType; c: var PackedEncoder; m: var PackedModule): PackedItemI
 proc toPackedLib(l: PLib; c: var PackedEncoder; m: var PackedModule): PackedLib =
  ## the plib hangs off the psym via the .annex field
  if l.isNil: return
-  result = PackedLib(kind: l.kind, generated: l.generated,
-    isOverridden: l.isOverridden, name: toLitId($l.name, m)
-  )
+  result.kind = l.kind
+  result.generated = l.generated
+  result.isOverridden = l.isOverridden
+  result.name = toLitId($l.name, m)
  storeNode(result, l, path)

 proc storeSym*(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId =
@@ -396,12 +397,12 @@ proc storeSym*(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId
  result = PackedItemId(module: toLitId(s.itemId.module.FileIndex, c, m), item: s.itemId.item)

  if s.itemId.module == c.thisModule and not c.symMarker.containsOrIncl(s.itemId.item):
-    #if s.itemId.item >= m.syms.len:
-    #  setLen m.syms, s.itemId.item+1
+    if s.itemId.item >= m.syms.len:
+      setLen m.syms, s.itemId.item+1

    assert sfForward notin s.flags

-    var p = PackedSym(id: s.itemId.item, kind: s.kind, flags: s.flags, info: s.info.toPackedInfo(c, m), magic: s.magic,
+    var p = PackedSym(kind: s.kind, flags: s.flags, info: s.info.toPackedInfo(c, m), magic: s.magic,
      position: s.position, offset: s.offset, disamb: s.disamb, options: s.options,
      name: s.name.s.toLitId(m))

@@ -414,7 +415,7 @@ proc storeSym*(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId
      p.bitsize = s.bitsize
      p.alignment = s.alignment

-    p.externalName = toLitId(s.loc.snippet, m)
+    p.externalName = toLitId(s.loc.r, m)
    p.locFlags = s.loc.flags
    c.addMissing s.typ
    p.typ = s.typ.storeType(c, m)
@@ -433,11 +434,11 @@ proc addModuleRef(n: PNode; ir: var PackedTree; c: var PackedEncoder; m: var Pac
  let info = n.info.toPackedInfo(c, m)
  if n.typ != n.sym.typ:
    ir.addNode(kind = nkModuleRef, operand = 3.int32, # spans 3 nodes in total
-               info = info, flags = n.flags,
+               info = info,
               typeId = storeTypeLater(n.typ, c, m))
  else:
    ir.addNode(kind = nkModuleRef, operand = 3.int32, # spans 3 nodes in total
-              info = info, flags = n.flags)
+              info = info)
  ir.addNode(kind = nkNone, info = info,
             operand = toLitId(n.sym.itemId.module.FileIndex, c, m).int32)
  ir.addNode(kind = nkNone, info = info,
@@ -613,10 +614,6 @@ proc loadRodFile*(filename: AbsoluteFile; m: var PackedModule; config: ConfigRef
    f.loadSection section
    f.loadSeq data

-  template loadTableSection(section, data) {.dirty.} =
-    f.loadSection section
-    f.loadOrderedTable data
-
  template loadTabSection(section, data) {.dirty.} =
    f.loadSection section
    f.load data
@@ -649,8 +646,8 @@ proc loadRodFile*(filename: AbsoluteFile; m: var PackedModule; config: ConfigRef
    loadTabSection topLevelSection, m.topLevel

    loadTabSection bodiesSection, m.bodies
-    loadTableSection symsSection, m.syms
-    loadTableSection typesSection, m.types
+    loadSeqSection symsSection, m.syms
+    loadSeqSection typesSection, m.types

    loadSeqSection typeInstCacheSection, m.typeInstCache
    loadSeqSection procInstCacheSection, m.procInstCache
@@ -695,10 +692,6 @@ proc saveRodFile*(filename: AbsoluteFile; encoder: var PackedEncoder; m: var Pac
    f.storeSection section
    f.store data

-  template storeTableSection(section, data) {.dirty.} =
-    f.storeSection section
-    f.storeOrderedTable data
-
  storeTabSection stringsSection, m.strings

  storeSeqSection checkSumsSection, m.includes
@@ -722,9 +715,9 @@ proc saveRodFile*(filename: AbsoluteFile; encoder: var PackedEncoder; m: var Pac
  storeTabSection topLevelSection, m.topLevel

  storeTabSection bodiesSection, m.bodies
-  storeTableSection symsSection, m.syms
+  storeSeqSection symsSection, m.syms

-  storeTableSection typesSection, m.types
+  storeSeqSection typesSection, m.types

  storeSeqSection typeInstCacheSection, m.typeInstCache
  storeSeqSection procInstCacheSection, m.procInstCache
@@ -775,8 +768,8 @@ type
    status*: ModuleStatus
    symsInit, typesInit, loadedButAliveSetChanged*: bool
    fromDisk*: PackedModule
-    syms: OrderedTable[int32, PSym] # indexed by itemId
-    types: OrderedTable[int32, PType]
+    syms: seq[PSym] # indexed by itemId
+    types: seq[PType]
    module*: PSym # the one true module symbol.
    iface, ifaceHidden: Table[PIdent, seq[PackedItemId]]
      # PackedItemId so that it works with reexported symbols too
@@ -837,8 +830,7 @@ proc loadNodes*(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
    result.ident = getIdent(c.cache, g[thisModule].fromDisk.strings[n.litId])
  of nkSym:
    result.sym = loadSym(c, g, thisModule, PackedItemId(module: LitId(0), item: tree[n].soperand))
-    if result.typ == nil:
-      result.typ() = result.sym.typ
+    if result.typ == nil: result.typ = result.sym.typ
  of externIntLit:
    result.intVal = g[thisModule].fromDisk.numbers[n.litId]
  of nkStrLit..nkTripleStrLit:
@@ -851,8 +843,7 @@ proc loadNodes*(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
    assert n2.kind == nkNone
    transitionNoneToSym(result)
    result.sym = loadSym(c, g, thisModule, PackedItemId(module: n1.litId, item: tree[n2].soperand))
-    if result.typ == nil:
-      result.typ() = result.sym.typ
+    if result.typ == nil: result.typ = result.sym.typ
  else:
    for n0 in sonsReadonly(tree, n):
      result.addAllowNil loadNodes(c, g, thisModule, tree, n0)
@@ -942,10 +933,10 @@ proc symBodyFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
    result.guard = loadSym(c, g, si, s.guard)
    result.bitsize = s.bitsize
    result.alignment = s.alignment
-  setOwner(result, loadSym(c, g, si, s.owner))
+  result.owner = loadSym(c, g, si, s.owner)
  let externalName = g[si].fromDisk.strings[s.externalName]
  if externalName != "":
-    result.loc.snippet = externalName
+    result.loc.r = rope externalName
  result.loc.flags = s.locFlags
  result.instantiatedFrom = loadSym(c, g, si, s.instantiatedFrom)

@@ -969,11 +960,11 @@ proc loadSym(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; s:
        loadToReplayNodes(g, c.config, c.cache, m, g[int m])

    assert g[si].status in {loaded, storing, stored}
-    #if not g[si].symsInit:
-    #  g[si].symsInit = true
-    #  setLen g[si].syms, g[si].fromDisk.syms.len
+    if not g[si].symsInit:
+      g[si].symsInit = true
+      setLen g[si].syms, g[si].fromDisk.syms.len

-    if g[si].syms.getOrDefault(s.item) == nil:
+    if g[si].syms[s.item] == nil:
      if g[si].fromDisk.syms[s.item].kind != skModule:
        result = symHeaderFromPacked(c, g, g[si].fromDisk.syms[s.item], si, s.item)
        # store it here early on, so that recursions work properly:
@@ -998,7 +989,7 @@ proc typeHeaderFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
 proc typeBodyFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
                        t: PackedType; si, item: int32; result: PType) =
  result.sym = loadSym(c, g, si, t.sym)
-  setOwner(result, loadSym(c, g, si, t.owner))
+  result.owner = loadSym(c, g, si, t.owner)
  when false:
    for op, item in pairs t.attachedOps:
      result.attachedOps[op] = loadSym(c, g, si, item)
@@ -1020,11 +1011,11 @@ proc loadType(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; t
    assert g[si].status in {loaded, storing, stored}
    assert t.item > 0

-    #if not g[si].typesInit:
-    #  g[si].typesInit = true
-    #  setLen g[si].types, g[si].fromDisk.types.len
+    if not g[si].typesInit:
+      g[si].typesInit = true
+      setLen g[si].types, g[si].fromDisk.types.len

-    if g[si].types.getOrDefault(t.item) == nil:
+    if g[si].types[t.item] == nil:
      result = typeHeaderFromPacked(c, g, g[si].fromDisk.types[t.item], si, t.item)
      # store it here early on, so that recursions work properly:
      g[si].types[t.item] = result
@@ -1062,7 +1053,7 @@ proc setupLookupTables(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCa
                  name: getIdent(cache, splitFile(filename).name),
                  info: newLineInfo(fileIdx, 1, 1),
                  position: int(fileIdx))
-  setOwner(m.module, getPackage(conf, cache, fileIdx))
+  m.module.owner = getPackage(conf, cache, fileIdx)
  m.module.flags = m.fromDisk.moduleFlags

 proc loadToReplayNodes(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
@@ -1163,7 +1154,10 @@ proc loadProcBody*(config: ConfigRef, cache: IdentCache;
 proc loadTypeFromId*(config: ConfigRef, cache: IdentCache;
                     g: var PackedModuleGraph; module: int; id: PackedItemId): PType =
  bench g.loadType:
-    result = g[module].types.getOrDefault(id.item)
+    if id.item < g[module].types.len:
+      result = g[module].types[id.item]
+    else:
+      result = nil
    if result == nil:
      var decoder = PackedDecoder(
        lastModule: int32(-1),
@@ -1176,7 +1170,10 @@ proc loadTypeFromId*(config: ConfigRef, cache: IdentCache;
 proc loadSymFromId*(config: ConfigRef, cache: IdentCache;
                    g: var PackedModuleGraph; module: int; id: PackedItemId): PSym =
  bench g.loadSym:
-    result = g[module].syms.getOrDefault(id.item)
+    if id.item < g[module].syms.len:
+      result = g[module].syms[id.item]
+    else:
+      result = nil
    if result == nil:
      var decoder = PackedDecoder(
        lastModule: int32(-1),
@@ -1192,6 +1189,19 @@ proc translateId*(id: PackedItemId; g: PackedModuleGraph; thisModule: int; confi
  else:
    ItemId(module: toFileIndex(id.module, g[thisModule].fromDisk, config).int32, item: id.item)

+proc checkForHoles(m: PackedModule; config: ConfigRef; moduleId: int) =
+  var bugs = 0
+  for i in 1 .. high(m.syms):
+    if m.syms[i].kind == skUnknown:
+      echo "EMPTY ID ", i, " module ", moduleId, " ", toFullPath(config, FileIndex(moduleId))
+      inc bugs
+  assert bugs == 0
+  when false:
+    var nones = 0
+    for i in 1 .. high(m.types):
+      inc nones, m.types[i].kind == tyNone
+    assert nones < 1
+
 proc simulateLoadedModule*(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
                           moduleSym: PSym; m: PackedModule) =
  # For now only used for heavy debugging. In the future we could use this to reduce the
--- a/compiler/ic/integrity.nim
+++ b/compiler/ic/integrity.nim
@@ -10,7 +10,7 @@
 ## Integrity checking for a set of .rod files.
 ## The set must cover a complete Nim project.

-import std/[sets, tables]
+import std/sets

 when defined(nimPreviewSlimSystem):
  import std/assertions
@@ -108,18 +108,18 @@ proc checkModule(c: var CheckedContext; m: PackedModule) =
  # We check that:
  # - Every symbol references existing types and symbols.
  # - Every tree node references existing types and symbols.
-  for _, v in pairs(m.syms):
-    checkLocalSym c, v.id
+  for i in 0..high(m.syms):
+    checkLocalSym c, int32(i)

  checkTree c, m.toReplay
  checkTree c, m.topLevel

  for e in m.exports:
-    #assert e[1] >= 0 and e[1] < m.syms.len
+    assert e[1] >= 0 and e[1] < m.syms.len
    assert e[0] == m.syms[e[1]].name

  for e in m.compilerProcs:
-    #assert e[1] >= 0 and e[1] < m.syms.len
+    assert e[1] >= 0 and e[1] < m.syms.len
    assert e[0] == m.syms[e[1]].name

  checkLocalSymIds c, m, m.converters
--- a/compiler/ic/navigator.nim
+++ b/compiler/ic/navigator.nim
@@ -11,7 +11,7 @@
 ## IDE-like features. It uses the set of .rod files to accomplish
 ## its task. The set must cover a complete Nim project.

-import std/[sets, tables]
+import std/sets

 from std/os import nil
 from std/private/miscdollars import toLocation
@@ -20,7 +20,7 @@ when defined(nimPreviewSlimSystem):
  import std/assertions

 import ".." / [ast, modulegraphs, msgs, options]
-import iclineinfos
+import ".." / nir / nirlineinfos
 import packed_ast, bitabs, ic

 type
--- a/compiler/ic/packed_ast.nim
+++ b/compiler/ic/packed_ast.nim
@@ -16,7 +16,7 @@ import std/[hashes, tables, strtabs]
 import bitabs, rodfiles
 import ".." / [ast, options]

-import iclineinfos
+import ".." / nir / nirlineinfos

 when defined(nimPreviewSlimSystem):
  import std/assertions
@@ -47,7 +47,6 @@ type
    path*: NodeId

  PackedSym* = object
-    id*: int32
    kind*: TSymKind
    name*: LitId
    typ*: PackedItemId
@@ -72,7 +71,6 @@ type
    instantiatedFrom*: PackedItemId

  PackedType* = object
-    id*: int32
    kind*: TTypeKind
    callConv*: TCallingConvention
    #nodekind*: TNodeKind
@@ -126,7 +124,7 @@ proc `==`*(a, b: NodePos): bool {.borrow.}
 proc `==`*(a, b: NodeId): bool {.borrow.}

 proc newTreeFrom*(old: PackedTree): PackedTree =
-  result = PackedTree(nodes: @[])
+  result.nodes = @[]
  when false: result.sh = old.sh

 proc addIdent*(tree: var PackedTree; s: LitId; info: PackedLineInfo) =
--- a/compiler/ic/rodfiles.nim
+++ b/compiler/ic/rodfiles.nim
@@ -19,8 +19,6 @@ from std/typetraits import supportsCopyMem
 when defined(nimPreviewSlimSystem):
  import std/[syncio, assertions]

-import std / tables
-
 ## Overview
 ## ========
 ## `RodFile` represents a Rod File (versioned binary format), and the
@@ -172,18 +170,6 @@ proc storeSeq*[T](f: var RodFile; s: seq[T]) =
    for i in 0..<s.len:
      storePrim(f, s[i])

-proc storeOrderedTable*[K, T](f: var RodFile; s: OrderedTable[K, T]) =
-  if f.err != ok: return
-  if s.len >= high(int32):
-    setError f, tooBig
-    return
-  var lenPrefix = int32(s.len)
-  if writeBuffer(f.f, addr lenPrefix, sizeof(lenPrefix)) != sizeof(lenPrefix):
-    setError f, ioFailure
-  else:
-    for _, v in s:
-      storePrim(f, v)
-
 proc loadPrim*(f: var RodFile; s: var string) =
  ## Read a string, the length was stored as a prefix
  if f.err != ok: return
@@ -225,19 +211,6 @@ proc loadSeq*[T](f: var RodFile; s: var seq[T]) =
    for i in 0..<lenPrefix:
      loadPrim(f, s[i])

-proc loadOrderedTable*[K, T](f: var RodFile; s: var OrderedTable[K, T]) =
-  ## `T` must be compatible with `copyMem`, see `loadPrim`
-  if f.err != ok: return
-  var lenPrefix = int32(0)
-  if readBuffer(f.f, addr lenPrefix, sizeof(lenPrefix)) != sizeof(lenPrefix):
-    setError f, ioFailure
-  else:
-    s = initOrderedTable[K, T](lenPrefix)
-    for i in 0..<lenPrefix:
-      var x = default T
-      loadPrim(f, x)
-      s[x.id] = x
-
 proc storeHeader*(f: var RodFile; cookie = defaultCookie) =
  ## stores the header which is described by `cookie`.
  if f.err != ok: return
--- a/compiler/importer.nim
+++ b/compiler/importer.nim
@@ -144,7 +144,7 @@ proc importSymbol(c: PContext, n: PNode, fromMod: PSym; importSet: var IntSet) =
    # for an enumeration we have to add all identifiers
    if multiImport:
      # for a overloadable syms add all overloaded routines
-      var it: ModuleIter = default(ModuleIter)
+      var it: ModuleIter
      var e = initModuleIter(it, c.graph, fromMod, s.name)
      while e != nil:
        if e.name.id != s.name.id: internalError(c.config, n.info, "importSymbol: 3")
@@ -231,7 +231,7 @@ proc importForwarded(c: PContext, n: PNode, exceptSet: IntSet; fromMod: PSym; im
    for i in 0..n.safeLen-1:
      importForwarded(c, n[i], exceptSet, fromMod, importSet)

-proc importModuleAs(c: PContext; n: PNode, realModule: PSym, importHidden, trackUnusedImport: bool): PSym =
+proc importModuleAs(c: PContext; n: PNode, realModule: PSym, importHidden: bool): PSym =
  result = realModule
  template createModuleAliasImpl(ident): untyped =
    createModuleAlias(realModule, c.idgen, ident, n.info, c.config.options)
@@ -246,16 +246,12 @@ proc importModuleAs(c: PContext; n: PNode, realModule: PSym, importHidden, track
    result = createModuleAliasImpl(realModule.name)
  if importHidden:
    result.options.incl optImportHidden
-  let moduleIdent = if n.kind in {nkInfix, nkImportAs}: n[^1] else: n
-  result.info = moduleIdent.info
-  if trackUnusedImport:
-    c.unusedImports.add((result, result.info))
+  c.unusedImports.add((result, n.info))
  c.importModuleMap[result.id] = realModule.id
  c.importModuleLookup.mgetOrPut(result.name.id, @[]).addUnique realModule.id

 proc transformImportAs(c: PContext; n: PNode): tuple[node: PNode, importHidden: bool] =
-  result = (nil, false)
-  var ret = default(typeof(result))
+  var ret: typeof(result)
  proc processPragma(n2: PNode): PNode =
    let (result2, kws) = splitPragmas(c, n2)
    result = result2
@@ -290,11 +286,10 @@ proc myImportModule(c: PContext, n: var PNode, importStmtResult: PNode): PSym =
                toFullPath(c.config, c.graph.importStack[i+1])
      c.recursiveDep = err

-    let trackUnusedImport = warnUnusedImportX in c.config.notes
    var realModule: PSym
    discard pushOptionEntry(c)
    realModule = c.graph.importModuleCallback(c.graph, c.module, f)
-    result = importModuleAs(c, n, realModule, transf.importHidden, trackUnusedImport)
+    result = importModuleAs(c, n, realModule, transf.importHidden)
    popOptionEntry(c)

    #echo "set back to ", L
@@ -311,15 +306,7 @@ proc myImportModule(c: PContext, n: var PNode, importStmtResult: PNode): PSym =
    if belongsToStdlib(c.graph, result) and not startsWith(moduleName, stdPrefix) and
        not startsWith(moduleName, "system/") and not startsWith(moduleName, "packages/"):
      message(c.config, n.info, warnStdPrefix, realModule.name.s)
-
-    proc suggestMod(n: PNode; s: PSym) =
-      if n.kind == nkImportAs:
-        suggestMod(n[0], realModule)
-      elif n.kind == nkInfix:
-        suggestMod(n[2], s)
-      else:
-        suggestSym(c.graph, n.info, s, c.graph.usageSym, false)
-    suggestMod(n, result)
+    suggestSym(c.graph, n.info, result, c.graph.usageSym, false)
    importStmtResult.add newSymNode(result, n.info)
    #newStrNode(toFullPath(c.config, f), n.info)
  else:
@@ -338,7 +325,7 @@ proc impMod(c: PContext; it: PNode; importStmtResult: PNode) =
  let m = myImportModule(c, it, importStmtResult)
  if m != nil:
    # ``addDecl`` needs to be done before ``importAllSymbols``!
-    addDecl(c, m) # add symbol to symbol table of module
+    addDecl(c, m, it.info) # add symbol to symbol table of module
    importAllSymbols(c, m)
    #importForwarded(c, m.ast, emptySet, m)
    afterImport(c, m)
@@ -375,7 +362,7 @@ proc evalFrom*(c: PContext, n: PNode): PNode =
  var m = myImportModule(c, n[0], result)
  if m != nil:
    n[0] = newSymNode(m)
-    addDecl(c, m)               # add symbol to symbol table of module
+    addDecl(c, m, n.info)               # add symbol to symbol table of module

    var im = ImportedModule(m: m, mode: importSet, imported: initIntSet())
    for i in 1..<n.len:
@@ -390,7 +377,7 @@ proc evalImportExcept*(c: PContext, n: PNode): PNode =
  var m = myImportModule(c, n[0], result)
  if m != nil:
    n[0] = newSymNode(m)
-    addDecl(c, m)               # add symbol to symbol table of module
+    addDecl(c, m, n.info)               # add symbol to symbol table of module
    importAllSymbolsExcept(c, m, readExceptSet(c, n))
    #importForwarded(c, m.ast, exceptSet, m)
    afterImport(c, m)
--- a/compiler/injectdestructors.nim
+++ b/compiler/injectdestructors.nim
@@ -163,8 +163,7 @@ proc isLastReadImpl(n: PNode; c: var Con; scope: var Scope): bool =
    result = false

 proc isLastRead(n: PNode; c: var Con; s: var Scope): bool =
-  # bug #23354; an object type could have a non-trival assignements when it is passed to a sink parameter
-  if not hasDestructor(c, n.typ) and (n.typ.kind != tyObject or isTrival(getAttachedOp(c.graph, n.typ, attachedAsgn))): return true
+  if not hasDestructor(c, n.typ): return true

  let m = skipConvDfa(n)
  result = (m.kind == nkSym and sfSingleUsedTemp in m.sym.flags) or
@@ -222,7 +221,7 @@ proc makePtrType(c: var Con, baseType: PType): PType =

 proc genOp(c: var Con; op: PSym; dest: PNode): PNode =
  var addrExp: PNode
-  if op.typ != nil and op.typ.signatureLen > 1 and op.typ.firstParamType.kind != tyVar:
+  if op.typ != nil and op.typ.len > 1 and op.typ[1].kind != tyVar:
    addrExp = dest
  else:
    addrExp = newNodeIT(nkHiddenAddr, dest.info, makePtrType(c, dest.typ))
@@ -300,7 +299,7 @@ proc genSink(c: var Con; s: var Scope; dest, ri: PNode; flags: set[MoveOrCopyFla
 proc isCriticalLink(dest: PNode): bool {.inline.} =
  #[
  Lins's idea that only "critical" links can introduce a cycle. This is
-  critical for the performance guarantees that we strive for: If you
+  critical for the performance gurantees that we strive for: If you
  traverse a data structure, no tracing will be performed at all.
  ORC is about this promise: The GC only touches the memory that the
  mutator touches too.
@@ -317,10 +316,9 @@ proc isCriticalLink(dest: PNode): bool {.inline.} =
  ]#
  result = dest.kind != nkSym

-proc finishCopy(c: var Con; result, dest: PNode; flags: set[MoveOrCopyFlag]; isFromSink: bool) =
-  if c.graph.config.selectedGC == gcOrc and IsExplicitSink notin flags:
-    # add cyclic flag, but not to sink calls, which IsExplicitSink generates
-    let t = dest.typ.skipTypes(tyUserTypeClasses + {tyGenericInst, tyAlias, tySink, tyDistinct})
+proc finishCopy(c: var Con; result, dest: PNode; isFromSink: bool) =
+  if c.graph.config.selectedGC == gcOrc:
+    let t = dest.typ.skipTypes({tyGenericInst, tyAlias, tySink, tyDistinct})
    if cyclicType(c.graph, t):
      result.add boolLit(c.graph, result.info, isFromSink or isCriticalLink(dest))

@@ -332,7 +330,7 @@ proc genMarkCyclic(c: var Con; result, dest: PNode) =
        result.add callCodegenProc(c.graph, "nimMarkCyclic", dest.info, dest)
      else:
        let xenv = genBuiltin(c.graph, c.idgen, mAccessEnv, "accessEnv", dest)
-        xenv.typ() = getSysType(c.graph, dest.info, tyPointer)
+        xenv.typ = getSysType(c.graph, dest.info, tyPointer)
        result.add callCodegenProc(c.graph, "nimMarkCyclic", dest.info, xenv)

 proc genCopyNoCheck(c: var Con; dest, ri: PNode; a: TTypeAttachedOp): PNode =
@@ -400,7 +398,7 @@ proc genWasMoved(c: var Con, n: PNode): PNode =
    result = genOp(c, op, n)
  else:
    result = newNodeI(nkCall, n.info)
-    result.add(newSymNode(createMagic(c.graph, c.idgen, "wasMoved", mWasMoved)))
+    result.add(newSymNode(createMagic(c.graph, c.idgen, "`=wasMoved`", mWasMoved)))
    result.add copyTree(n) #mWasMoved does not take the address
    #if n.kind != nkSym:
    #  message(c.graph.config, n.info, warnUser, "wasMoved(" & $n & ")")
@@ -408,15 +406,12 @@ proc genWasMoved(c: var Con, n: PNode): PNode =
 proc genDefaultCall(t: PType; c: Con; info: TLineInfo): PNode =
  result = newNodeI(nkCall, info)
  result.add(newSymNode(createMagic(c.graph, c.idgen, "default", mDefault)))
-  result.typ() = t
+  result.typ = t

 proc destructiveMoveVar(n: PNode; c: var Con; s: var Scope): PNode =
  # generate: (let tmp = v; reset(v); tmp)
  if (not hasDestructor(c, n.typ)) and c.inEnsureMove == 0:
-    assert n.kind != nkSym or not hasDestructor(c, n.sym.typ) or
-          (n.typ.kind == tyPtr and n.sym.typ.kind == tyRef)
-      # bug #23505; transformed by `transf`: addr (deref ref) -> ptr
-      # we know it's really a pointer; so here we assign it directly
+    assert n.kind != nkSym or not hasDestructor(c, n.sym.typ)
    result = copyTree(n)
  else:
    result = newNodeIT(nkStmtListExpr, n.info, n.typ)
@@ -447,25 +442,24 @@ proc isCapturedVar(n: PNode): bool =

 proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
  result = newNodeIT(nkStmtListExpr, n.info, n.typ)
-  let nTyp = n.typ.skipTypes(tyUserTypeClasses)
-  let tmp = c.getTemp(s, nTyp, n.info)
-  if hasDestructor(c, nTyp):
-    let typ = nTyp.skipTypes({tyGenericInst, tyAlias, tySink})
+  let tmp = c.getTemp(s, n.typ, n.info)
+  if hasDestructor(c, n.typ):
+    let typ = n.typ.skipTypes({tyGenericInst, tyAlias, tySink})
    let op = getAttachedOp(c.graph, typ, attachedDup)
    if op != nil and tfHasOwned notin typ.flags:
      if sfError in op.flags:
-        c.checkForErrorPragma(nTyp, n, "=dup")
+        c.checkForErrorPragma(n.typ, n, "=dup")
      else:
        let copyOp = getAttachedOp(c.graph, typ, attachedAsgn)
        if copyOp != nil and sfError in copyOp.flags and
           sfOverridden notin op.flags:
-          c.checkForErrorPragma(nTyp, n, "=dup", inferredFromCopy = true)
+          c.checkForErrorPragma(n.typ, n, "=dup", inferredFromCopy = true)

      let src = p(n, c, s, normal)
      var newCall = newTreeIT(nkCall, src.info, src.typ,
            newSymNode(op),
            src)
-      c.finishCopy(newCall, n, {}, isFromSink = true)
+      c.finishCopy(newCall, n, isFromSink = true)
      result.add newTreeI(nkFastAsgn,
          src.info, tmp,
          newCall
@@ -474,9 +468,9 @@ proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
      result.add c.genWasMoved(tmp)
      var m = c.genCopy(tmp, n, {})
      m.add p(n, c, s, normal)
-      c.finishCopy(m, n, {}, isFromSink = true)
+      c.finishCopy(m, n, isFromSink = true)
      result.add m
-    if isLValue(n) and not isCapturedVar(n) and nTyp.skipTypes(abstractInst).kind != tyRef and c.inSpawn == 0:
+    if isLValue(n) and not isCapturedVar(n) and n.typ.skipTypes(abstractInst).kind != tyRef and c.inSpawn == 0:
      message(c.graph.config, n.info, hintPerformance,
        ("passing '$1' to a sink parameter introduces an implicit copy; " &
        "if possible, rearrange your program's control flow to prevent it") % $n)
@@ -485,8 +479,8 @@ proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
        ("cannot move '$1', passing '$1' to a sink parameter introduces an implicit copy") % $n)
  else:
    if c.graph.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
-      assert(not containsManagedMemory(nTyp))
-    if nTyp.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
+      assert(not containsManagedMemory(n.typ))
+    if n.typ.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
      localError(c.graph.config, n.info, "cannot create an implicit openArray copy to be passed to a sink parameter")
    result.add newTree(nkAsgn, tmp, p(n, c, s, normal))
  # Since we know somebody will take over the produced copy, there is
@@ -495,14 +489,14 @@ proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =

 proc isDangerousSeq(t: PType): bool {.inline.} =
  let t = t.skipTypes(abstractInst)
-  result = t.kind == tySequence and tfHasOwned notin t.elementType.flags
+  result = t.kind == tySequence and tfHasOwned notin t[0].flags

 proc containsConstSeq(n: PNode): bool =
  if n.kind == nkBracket and n.len > 0 and n.typ != nil and isDangerousSeq(n.typ):
    return true
  result = false
  case n.kind
-  of nkExprEqExpr, nkExprColonExpr, nkHiddenStdConv, nkHiddenSubConv, nkCast:
+  of nkExprEqExpr, nkExprColonExpr, nkHiddenStdConv, nkHiddenSubConv:
    result = containsConstSeq(n[1])
  of nkObjConstr, nkClosure:
    for i in 1..<n.len:
@@ -600,9 +594,7 @@ template processScopeExpr(c: var Con; s: var Scope; ret: PNode, processCall: unt
  # tricky because you would have to intercept moveOrCopy at a certain point
  let tmp = c.getTemp(s.parent[], ret.typ, ret.info)
  tmp.sym.flags = tmpFlags
-  let cpy = if hasDestructor(c, ret.typ) and
-                ret.typ.kind notin {tyOpenArray, tyVarargs}:
-                # bug #23247 we don't own the data, so it's harmful to destroy it
+  let cpy = if hasDestructor(c, ret.typ):
              s.parent[].final.add c.genDestroy(tmp)
              moveOrCopy(tmp, ret, c, s, {IsDecl})
            else:
@@ -654,7 +646,7 @@ template handleNestedTempl(n, processCall: untyped, willProduceStmt = false,
      for j in 0 ..< it.len-1:
        branch[j] = copyTree(it[j])
      var ofScope = nestedScope(s, it.lastSon)
-      branch[^1] = if n.typ.isEmptyType or it[^1].typ.isEmptyType or willProduceStmt:
+      branch[^1] = if it[^1].typ.isEmptyType or willProduceStmt:
                     processScope(c, ofScope, maybeVoid(it[^1], ofScope))
                   else:
                     processScopeExpr(c, ofScope, it[^1], processCall, tmpFlags)
@@ -702,7 +694,7 @@ template handleNestedTempl(n, processCall: untyped, willProduceStmt = false,
        #Condition needs to be destroyed outside of the condition/branch scope
        branch[0] = p(it[0], c, s, normal)

-      branch[^1] = if n.typ.isEmptyType or it[^1].typ.isEmptyType or willProduceStmt:
+      branch[^1] = if it[^1].typ.isEmptyType or willProduceStmt:
                     processScope(c, branchScope, maybeVoid(it[^1], branchScope))
                   else:
                     processScopeExpr(c, branchScope, it[^1], processCall, tmpFlags)
@@ -762,7 +754,7 @@ proc pRaiseStmt(n: PNode, c: var Con; s: var Scope): PNode =
      let tmp = c.getTemp(s, n[0].typ, n.info)
      var m = c.genCopyNoCheck(tmp, n[0], attachedAsgn)
      m.add p(n[0], c, s, normal)
-      c.finishCopy(m, n[0], {}, isFromSink = false)
+      c.finishCopy(m, n[0], isFromSink = false)
      result = newTree(nkStmtList, c.genWasMoved(tmp), m)
      var toDisarm = n[0]
      if toDisarm.kind == nkStmtListExpr: toDisarm = toDisarm.lastSon
@@ -777,18 +769,6 @@ proc pRaiseStmt(n: PNode, c: var Con; s: var Scope): PNode =
      result.add copyNode(n[0])
  s.needsTry = true

-template isCustomDestructor(c: Con, t: PType): bool =
-  hasDestructor(c, t) and
-          getAttachedOp(c.graph, t, attachedDestructor) != nil and
-          sfOverridden in getAttachedOp(c.graph, t, attachedDestructor).flags
-
-proc hasCustomDestructor(c: Con, t: PType): bool =
-  result = isCustomDestructor(c, t)
-  var obj = t
-  while obj.baseClass != nil:
-    obj = skipTypes(obj.baseClass, abstractPtrs)
-    result = result or isCustomDestructor(c, obj)
-
 proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSingleUsedTemp}; inReturn = false): PNode =
  if n.kind in {nkStmtList, nkStmtListExpr, nkBlockStmt, nkBlockExpr, nkIfStmt,
                nkIfExpr, nkCaseStmt, nkWhen, nkWhileStmt, nkParForStmt, nkTryStmt, nkPragmaBlock}:
@@ -802,7 +782,15 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
      result = passCopyToSink(n, c, s)
    elif n.kind in {nkBracket, nkObjConstr, nkTupleConstr, nkClosure, nkNilLit} +
         nkCallKinds + nkLiterals:
-      result = p(n, c, s, consumed)
+      if n.kind in nkCallKinds and n[0].kind == nkSym:
+        if n[0].sym.magic == mEnsureMove:
+          inc c.inEnsureMove
+          result = p(n[1], c, s, sinkArg)
+          dec c.inEnsureMove
+        else:
+          result = p(n, c, s, consumed)
+      else:
+        result = p(n, c, s, consumed)
    elif ((n.kind == nkSym and isSinkParam(n.sym)) or isAnalysableFieldAccess(n, c.owner)) and
        isLastRead(n, c, s) and not (n.kind == nkSym and isCursor(n)):
      # Sinked params can be consumed only once. We need to reset the memory
@@ -814,17 +802,14 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
          n[1].typ.skipTypes(abstractInst-{tyOwned}).kind == tyOwned:
        # allow conversions from owned to unowned via this little hack:
        let nTyp = n[1].typ
-        n[1].typ() = n.typ
+        n[1].typ = n.typ
        result[1] = p(n[1], c, s, sinkArg)
-        result[1].typ() = nTyp
+        result[1].typ = nTyp
      else:
        result[1] = p(n[1], c, s, sinkArg)
    elif n.kind in {nkObjDownConv, nkObjUpConv}:
      result = copyTree(n)
      result[0] = p(n[0], c, s, sinkArg)
-    elif n.kind == nkCast and n.typ.skipTypes(abstractInst).kind in {tyString, tySequence}:
-      result = copyTree(n)
-      result[1] = p(n[1], c, s, sinkArg)
    elif n.typ == nil:
      # 'raise X' can be part of a 'case' expression. Deal with it here:
      result = p(n, c, s, normal)
@@ -868,25 +853,31 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
      for i in 1..<n.len:
        if n[i].kind == nkExprColonExpr:
          let field = lookupFieldAgain(t, n[i][0].sym)
-          if field != nil and (sfCursor in field.flags or field.typ.kind in {tyOpenArray, tyVarargs}):
-            # don't sink fields with openarray types
+          if field != nil and sfCursor in field.flags:
            result[i][1] = p(n[i][1], c, s, normal)
          else:
            result[i][1] = p(n[i][1], c, s, m)
        else:
          result[i] = p(n[i], c, s, m)
-      if mode == normal and (isRefConstr or hasCustomDestructor(c, t)):
+      if mode == normal and (isRefConstr or (hasDestructor(c, t) and
+        getAttachedOp(c.graph, t, attachedDestructor) != nil and
+        sfOverridden in getAttachedOp(c.graph, t, attachedDestructor).flags)):
        result = ensureDestruction(result, n, c, s)
    of nkCallKinds:
+      if n[0].kind == nkSym and n[0].sym.magic == mEnsureMove:
+        inc c.inEnsureMove
+        result = p(n[1], c, s, sinkArg)
+        dec c.inEnsureMove
+        return
+
      let inSpawn = c.inSpawn
      if n[0].kind == nkSym and n[0].sym.magic == mSpawn:
        c.inSpawn.inc
      elif c.inSpawn > 0:
        c.inSpawn.dec

-      # bug #23907; skips tyGenericInst for generic callbacks
-      let parameters = if n[0].typ != nil: n[0].typ.skipTypes(abstractInst) else: n[0].typ
-      let L = if parameters != nil: parameters.signatureLen else: 0
+      let parameters = n[0].typ
+      let L = if parameters != nil: parameters.len else: 0

      when false:
        var isDangerous = false
@@ -895,19 +886,13 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
          isDangerous = true

      result = shallowCopy(n)
-
-      if n[0].kind == nkSym and n[0].sym.magic == mEnsureMove:
-        inc c.inEnsureMove
-        result[1] = p(n[1], c, s, sinkArg)
-        dec c.inEnsureMove
-      else:
-        for i in 1..<n.len:
-          if i < L and isCompileTimeOnly(parameters[i]):
-            result[i] = n[i]
-          elif i < L and (isSinkTypeForParam(parameters[i]) or inSpawn > 0):
-            result[i] = p(n[i], c, s, sinkArg)
-          else:
-            result[i] = p(n[i], c, s, normal)
+      for i in 1..<n.len:
+        if i < L and isCompileTimeOnly(parameters[i]):
+          result[i] = n[i]
+        elif i < L and (isSinkTypeForParam(parameters[i]) or inSpawn > 0):
+          result[i] = p(n[i], c, s, sinkArg)
+        else:
+          result[i] = p(n[i], c, s, normal)

      when false:
        if isDangerous:
@@ -922,10 +907,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
        result[0] = p(n[0], c, s, normal)
      if canRaise(n[0]): s.needsTry = true
      if mode == normal:
-        if result.typ != nil and result.typ.kind notin {tyOpenArray, tyVarargs}:
-          # Returns of openarray types shouldn't be destroyed
-          # bug #19435; # bug #23247
-          result = ensureDestruction(result, n, c, s)
+        result = ensureDestruction(result, n, c, s)
    of nkDiscardStmt: # Small optimization
      result = shallowCopy(n)
      if n[0].kind != nkEmpty:
@@ -1014,9 +996,9 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
          n[1].typ.skipTypes(abstractInst-{tyOwned}).kind == tyOwned:
        # allow conversions from owned to unowned via this little hack:
        let nTyp = n[1].typ
-        n[1].typ() = n.typ
+        n[1].typ = n.typ
        result[1] = p(n[1], c, s, mode)
-        result[1].typ() = nTyp
+        result[1].typ = nTyp
      else:
        result[1] = p(n[1], c, s, mode)

@@ -1166,7 +1148,7 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
        result = c.genCopy(dest, ri, flags)
        dec c.inEnsureMove, isEnsureMove
        result.add p(ri, c, s, consumed)
-        c.finishCopy(result, dest, flags, isFromSink = false)
+        c.finishCopy(result, dest, isFromSink = false)
    of nkBracket:
      # array constructor
      if ri.len > 0 and isDangerousSeq(ri.typ):
@@ -1174,7 +1156,7 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
        result = c.genCopy(dest, ri, flags)
        dec c.inEnsureMove, isEnsureMove
        result.add p(ri, c, s, consumed)
-        c.finishCopy(result, dest, flags, isFromSink = false)
+        c.finishCopy(result, dest, isFromSink = false)
      else:
        result = c.genSink(s, dest, p(ri, c, s, consumed), flags)
    of nkObjConstr, nkTupleConstr, nkClosure, nkCharLit..nkNilLit:
@@ -1184,9 +1166,9 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
        # Rule 3: `=sink`(x, z); wasMoved(z)
        let snk = c.genSink(s, dest, ri, flags)
        result = newTree(nkStmtList, snk, c.genWasMoved(ri))
-      elif ri.sym.kind != skParam and
-          isAnalysableFieldAccess(ri, c.owner) and
-          isLastRead(ri, c, s) and canBeMoved(c, dest.typ):
+      elif ri.sym.kind != skParam and ri.sym.owner == c.owner and
+          isLastRead(ri, c, s) and canBeMoved(c, dest.typ) and not isCursor(ri) and
+          not ({sfGlobal, sfPure} <= ri.sym.flags):
        # Rule 3: `=sink`(x, z); wasMoved(z)
        let snk = c.genSink(s, dest, ri, flags)
        result = newTree(nkStmtList, snk, c.genWasMoved(ri))
@@ -1195,13 +1177,10 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
        result = c.genCopy(dest, ri, flags)
        dec c.inEnsureMove, isEnsureMove
        result.add p(ri, c, s, consumed)
-        c.finishCopy(result, dest, flags, isFromSink = false)
+        c.finishCopy(result, dest, isFromSink = false)
    of nkHiddenSubConv, nkHiddenStdConv, nkConv, nkObjDownConv, nkObjUpConv, nkCast:
-      if IsExplicitSink in flags:
-        result = c.genSink(s, dest, p(ri, c, s, consumed), flags)
-      else:
-        result = c.genSink(s, dest, p(ri, c, s, sinkArg), flags)
-    of nkStmtListExpr, nkBlockExpr, nkIfExpr, nkCaseStmt, nkTryStmt, nkPragmaBlock:
+      result = c.genSink(s, dest, p(ri, c, s, sinkArg), flags)
+    of nkStmtListExpr, nkBlockExpr, nkIfExpr, nkCaseStmt, nkTryStmt:
      template process(child, s): untyped = moveOrCopy(dest, child, c, s, flags)
      # We know the result will be a stmt so we use that fact to optimize
      handleNestedTempl(ri, process, willProduceStmt = true)
@@ -1218,7 +1197,7 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
        result = c.genCopy(dest, ri, flags)
        dec c.inEnsureMove, isEnsureMove
        result.add p(ri, c, s, consumed)
-        c.finishCopy(result, dest, flags, isFromSink = false)
+        c.finishCopy(result, dest, isFromSink = false)

 when false:
  proc computeUninit(c: var Con) =
--- a/compiler/installer.ini
+++ b/compiler/installer.ini
@@ -6,11 +6,11 @@ Name: "Nim"
 Version: "$version"
 Platforms: """
  windows: i386;amd64
-  linux: i386;hppa;ia64;alpha;amd64;powerpc64;arm;sparc;sparc64;m68k;mips;mipsel;mips64;mips64el;powerpc;powerpc64el;arm64;riscv32;riscv64;loongarch64
+  linux: i386;hppa;ia64;alpha;amd64;powerpc64;arm;sparc;sparc64;m68k;mips;mipsel;mips64;mips64el;powerpc;powerpc64el;arm64;riscv32;riscv64
  macosx: i386;amd64;powerpc64;arm64
  solaris: i386;amd64;sparc;sparc64
  freebsd: i386;amd64;powerpc64;arm;arm64;riscv64;sparc64;mips;mipsel;mips64;mips64el;powerpc;powerpc64el
-  netbsd: i386;amd64;arm64
+  netbsd: i386;amd64
  openbsd: i386;amd64;arm;arm64
  dragonfly: i386;amd64
  crossos: amd64
@@ -147,4 +147,4 @@ licenses: "bin/nim,MIT;lib/*,MIT;"

 [nimble]
 pkgName: "nim"
-pkgFiles: "compiler/*;doc/basicopt.txt;doc/advopt.txt;doc/nimdoc.css;doc/nimdoc.cls"
+pkgFiles: "compiler/*;doc/basicopt.txt;doc/advopt.txt;doc/nimdoc.css"
--- a/compiler/int128.nim
+++ b/compiler/int128.nim
@@ -34,7 +34,6 @@ proc `$`*(a: Int128): string

 proc toInt128*[T: SomeInteger | bool](arg: T): Int128 =
  {.noSideEffect.}:
-    result = Zero
    when T is bool: result.sdata(0) = int32(arg)
    elif T is SomeUnsignedInt:
      when sizeof(arg) <= 4:
@@ -209,35 +208,30 @@ proc `==`*(a, b: Int128): bool =
  return true

 proc bitnot*(a: Int128): Int128 =
-  result = Zero
  result.udata[0] = not a.udata[0]
  result.udata[1] = not a.udata[1]
  result.udata[2] = not a.udata[2]
  result.udata[3] = not a.udata[3]

 proc bitand*(a, b: Int128): Int128 =
-  result = Zero
  result.udata[0] = a.udata[0] and b.udata[0]
  result.udata[1] = a.udata[1] and b.udata[1]
  result.udata[2] = a.udata[2] and b.udata[2]
  result.udata[3] = a.udata[3] and b.udata[3]

 proc bitor*(a, b: Int128): Int128 =
-  result = Zero
  result.udata[0] = a.udata[0] or b.udata[0]
  result.udata[1] = a.udata[1] or b.udata[1]
  result.udata[2] = a.udata[2] or b.udata[2]
  result.udata[3] = a.udata[3] or b.udata[3]

 proc bitxor*(a, b: Int128): Int128 =
-  result = Zero
  result.udata[0] = a.udata[0] xor b.udata[0]
  result.udata[1] = a.udata[1] xor b.udata[1]
  result.udata[2] = a.udata[2] xor b.udata[2]
  result.udata[3] = a.udata[3] xor b.udata[3]

 proc `shr`*(a: Int128, b: int): Int128 =
-  result = Zero
  let b = b and 127
  if b < 32:
    result.sdata(3) = a.sdata(3) shr b
@@ -264,7 +258,6 @@ proc `shr`*(a: Int128, b: int): Int128 =
    result.sdata(0) = a.sdata(3) shr (b and 31)

 proc `shl`*(a: Int128, b: int): Int128 =
-  result = Zero
  let b = b and 127
  if b < 32:
    result.udata[0] = a.udata[0] shl b
@@ -288,7 +281,6 @@ proc `shl`*(a: Int128, b: int): Int128 =
    result.udata[3] = a.udata[0] shl (b and 31)

 proc `+`*(a, b: Int128): Int128 =
-  result = Zero
  let tmp0 = uint64(a.udata[0]) + uint64(b.udata[0])
  result.udata[0] = cast[uint32](tmp0)
  let tmp1 = uint64(a.udata[1]) + uint64(b.udata[1]) + (tmp0 shr 32)
@@ -321,7 +313,6 @@ proc abs(a: int32): int =
  if a < 0: -a else: a

 proc `*`(a: Int128, b: uint32): Int128 =
-  result = Zero
  let tmp0 = uint64(a.udata[0]) * uint64(b)
  let tmp1 = uint64(a.udata[1]) * uint64(b)
  let tmp2 = uint64(a.udata[2]) * uint64(b)
@@ -344,7 +335,6 @@ proc `*=`(a: var Int128, b: int32) =
  a = a * b

 proc makeInt128(high, low: uint64): Int128 =
-  result = Zero
  result.udata[0] = cast[uint32](low)
  result.udata[1] = cast[uint32](low shr 32)
  result.udata[2] = cast[uint32](high)
@@ -383,8 +373,6 @@ proc fastLog2*(a: Int128): int =

 proc divMod*(dividend, divisor: Int128): tuple[quotient, remainder: Int128] =
  assert(divisor != Zero)
-  result = (Zero, Zero)
-
  let isNegativeA = isNegative(dividend)
  let isNegativeB = isNegative(divisor)

@@ -551,28 +539,24 @@ proc toInt128*(arg: float64): Int128 =
    return res

 proc maskUInt64*(arg: Int128): Int128 {.noinit, inline.} =
-  result = Zero
  result.udata[0] = arg.udata[0]
  result.udata[1] = arg.udata[1]
  result.udata[2] = 0
  result.udata[3] = 0

 proc maskUInt32*(arg: Int128): Int128 {.noinit, inline.} =
-  result = Zero
  result.udata[0] = arg.udata[0]
  result.udata[1] = 0
  result.udata[2] = 0
  result.udata[3] = 0

 proc maskUInt16*(arg: Int128): Int128 {.noinit, inline.} =
-  result = Zero
  result.udata[0] = arg.udata[0] and 0xffff
  result.udata[1] = 0
  result.udata[2] = 0
  result.udata[3] = 0

 proc maskUInt8*(arg: Int128): Int128 {.noinit, inline.} =
-  result = Zero
  result.udata[0] = arg.udata[0] and 0xff
  result.udata[1] = 0
  result.udata[2] = 0
--- a/compiler/isolation_check.nim
+++ b/compiler/isolation_check.nim
@@ -54,18 +54,18 @@ proc canAlias(arg, ret: PType; marker: var IntSet): bool =
  of tyObject:
    if isFinal(ret):
      result = canAliasN(arg, ret.n, marker)
-      if not result and ret.baseClass != nil:
-        result = canAlias(arg, ret.baseClass, marker)
+      if not result and ret.len > 0 and ret[0] != nil:
+        result = canAlias(arg, ret[0], marker)
    else:
      result = true
  of tyTuple:
    result = false
-    for r in ret.kids:
-      result = canAlias(arg, r, marker)
+    for i in 0..<ret.len:
+      result = canAlias(arg, ret[i], marker)
      if result: break
  of tyArray, tySequence, tyDistinct, tyGenericInst,
     tyAlias, tyInferred, tySink, tyLent, tyOwned, tyRef:
-    result = canAlias(arg, ret.skipModifier, marker)
+    result = canAlias(arg, ret.lastSon, marker)
  of tyProc:
    result = ret.callConv == ccClosure
  else:
@@ -119,16 +119,14 @@ proc containsDangerousRefAux(t: PType; marker: var IntSet): SearchResult =
  if result != NotFound: return result
  case t.kind
  of tyObject:
-    if t.baseClass != nil:
-      result = containsDangerousRefAux(t.baseClass.skipTypes(skipPtrs), marker)
+    if t[0] != nil:
+      result = containsDangerousRefAux(t[0].skipTypes(skipPtrs), marker)
    if result == NotFound: result = containsDangerousRefAux(t.n, marker)
  of tyGenericInst, tyDistinct, tyAlias, tySink:
-    result = containsDangerousRefAux(skipModifier(t), marker)
-  of tyArray, tySet, tySequence:
-    result = containsDangerousRefAux(t.elementType, marker)
-  of tyTuple:
-    for a in t.kids:
-      result = containsDangerousRefAux(a, marker)
+    result = containsDangerousRefAux(lastSon(t), marker)
+  of tyArray, tySet, tyTuple, tySequence:
+    for i in 0..<t.len:
+      result = containsDangerousRefAux(t[i], marker)
      if result == Found: return result
  else:
    discard
@@ -166,7 +164,7 @@ proc containsVariable(n: PNode): bool =
 proc checkIsolate*(n: PNode): bool =
  if types.containsTyRef(n.typ):
    # XXX Maybe require that 'n.typ' is acyclic. This is not much
-    # worse than the already existing inheritance and closure restrictions.
+    # worse than the already exisiting inheritance and closure restrictions.
    case n.kind
    of nkCharLit..nkNilLit:
      result = true
--- a/compiler/jsgen.nim
+++ b/compiler/jsgen.nim
@@ -31,10 +31,9 @@ implements the required case distinction.
 import
  ast, trees, magicsys, options,
  nversion, msgs, idents, types,
-  ropes, wordrecg, renderer,
+  ropes, ccgutils, wordrecg, renderer,
  cgmeth, lowerings, sighashes, modulegraphs, lineinfos,
-  transf, injectdestructors, sourcemap, astmsgs, pushpoppragmas,
-  mangleutils
+  transf, injectdestructors, sourcemap, astmsgs, backendpragmas

 import pipelineutils

@@ -103,33 +102,29 @@ type
    prc: PSym
    globals, locals, body: Rope
    options: TOptions
-    optionsStack: seq[(TOptions, TNoteKinds)]
+    optionsStack: seq[TOptions]
    module: BModule
    g: PGlobals
+    generatedParamCopies: IntSet
    beforeRetNeeded: bool
    unique: int    # for temp identifier generation
    blocks: seq[TBlock]
    extraIndent: int
-    previousFileName: string  # For frameInfo inside templates.
-    # legacy: generatedParamCopies and up fields are used for jsNoLambdaLifting
-    generatedParamCopies: IntSet
    up: PProc     # up the call chain; required for closure support
+    declaredGlobals: IntSet
+    previousFileName: string  # For frameInfo inside templates.

 template config*(p: PProc): ConfigRef = p.module.config

 proc indentLine(p: PProc, r: Rope): Rope =
  var p = p
-  if jsNoLambdaLifting in p.config.legacyFeatures:
-    var ind = 0
-    while true:
-      inc ind, p.blocks.len + p.extraIndent
-      if p.up == nil or p.up.prc != p.prc.owner:
-        break
-      p = p.up
-    result = repeat(' ', ind*2) & r
-  else:
-    let ind = p.blocks.len + p.extraIndent
-    result = repeat(' ', ind*2) & r
+  var ind = 0
+  while true:
+    inc ind, p.blocks.len + p.extraIndent
+    if p.up == nil or p.up.prc != p.prc.owner:
+      break
+    p = p.up
+  result = repeat(' ', ind*2) & r

 template line(p: PProc, added: string) =
  p.body.add(indentLine(p, rope(added)))
@@ -180,6 +175,10 @@ proc initProcOptions(module: BModule): TOptions =
 proc newInitProc(globals: PGlobals, module: BModule): PProc =
  result = newProc(globals, module, nil, initProcOptions(module))

+proc declareGlobal(p: PProc; id: int; r: Rope) =
+  if p.prc != nil and not p.declaredGlobals.containsOrIncl(id):
+    p.locals.addf("global $1;$n", [r])
+
 const
  MappedToObject = {tyObject, tyArray, tyTuple, tyOpenArray,
    tySet, tyVarargs}
@@ -188,16 +187,16 @@ proc mapType(typ: PType): TJSTypeKind =
  let t = skipTypes(typ, abstractInst)
  case t.kind
  of tyVar, tyRef, tyPtr:
-    if skipTypes(t.elementType, abstractInst).kind in MappedToObject:
+    if skipTypes(t.lastSon, abstractInst).kind in MappedToObject:
      result = etyObject
    else:
      result = etyBaseIndex
  of tyPointer:
    # treat a tyPointer like a typed pointer to an array of bytes
    result = etyBaseIndex
-  of tyRange, tyDistinct, tyOrdinal, tyError, tyLent:
+  of tyRange, tyDistinct, tyOrdinal, tyProxy, tyLent:
    # tyLent is no-op as JS has pass-by-reference semantics
-    result = mapType(skipModifier t)
+    result = mapType(t[0])
  of tyInt..tyInt64, tyUInt..tyUInt64, tyEnum, tyChar: result = etyInt
  of tyBool: result = etyBool
  of tyFloat..tyFloat128: result = etyFloat
@@ -213,9 +212,9 @@ proc mapType(typ: PType): TJSTypeKind =
    result = etyNone
  of tyGenericInst, tyInferred, tyAlias, tyUserTypeClass, tyUserTypeClassInst,
     tySink, tyOwned:
-    result = mapType(typ.skipModifier)
+    result = mapType(typ.lastSon)
  of tyStatic:
-    if t.n != nil: result = mapType(skipModifier t)
+    if t.n != nil: result = mapType(lastSon t)
    else: result = etyNone
  of tyProc: result = etyProc
  of tyCstring: result = etyString
@@ -246,7 +245,7 @@ proc mangleName(m: BModule, s: PSym): Rope =
    for chr in name:
      if chr notin {'A'..'Z','a'..'z','_','$','0'..'9'}:
        return false
-  result = s.loc.snippet
+  result = s.loc.r
  if result == "":
    if s.kind == skField and s.name.s.validJsName:
      result = rope(s.name.s)
@@ -270,14 +269,10 @@ proc mangleName(m: BModule, s: PSym): Rope =
        # When hot reloading is enabled, we must ensure that the names
        # of functions and types will be preserved across rebuilds:
        result.add(idOrSig(s, m.module.name.s, m.sigConflicts, m.config))
-      elif s.kind == skParam:
-        result.add mangleParamExt(s)
-      elif s.kind in routineKinds:
-        result.add mangleProcNameExt(m.graph, s)
      else:
        result.add("_")
        result.add(rope(s.id))
-    s.loc.snippet = result
+    s.loc.r = result

 proc escapeJSString(s: string): string =
  result = newStringOfCap(s.len + s.len shr 2)
@@ -469,6 +464,9 @@ const # magic checked op; magic unchecked op;
    mUnaryMinusF64: ["", ""],
    mCharToStr: ["nimCharToStr", "nimCharToStr"],
    mBoolToStr: ["nimBoolToStr", "nimBoolToStr"],
+    mIntToStr: ["cstrToNimstr", "cstrToNimstr"],
+    mInt64ToStr: ["cstrToNimstr", "cstrToNimstr"],
+    mFloatToStr: ["cstrToNimstr", "cstrToNimstr"],
    mCStrToStr: ["cstrToNimstr", "cstrToNimstr"],
    mStrToStr: ["", ""]]

@@ -518,7 +516,7 @@ proc maybeMakeTempAssignable(p: PProc, n: PNode; x: TCompRes): tuple[a, tmp: Rop
      let (m1, tmp1) = maybeMakeTemp(p, n[0], address)
      let typ = skipTypes(n[0].typ, abstractPtrs)
      if typ.kind == tyArray:
-        first = firstOrd(p.config, typ.indexType)
+        first = firstOrd(p.config, typ[0])
      if optBoundsCheck in p.options:
        useMagic(p, "chckIndx")
        if first == 0: # save a couple chars
@@ -611,17 +609,6 @@ template unaryExpr(p: PProc, n: PNode, r: var TCompRes, magic, frmt: string) =
  r.res = frmt % [a, tmp]
  r.kind = resExpr

-proc genBreakState(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes = default(TCompRes)
-  # mangle `:state` properly somehow
-  if n.kind == nkClosure:
-    gen(p, n[1], a)
-    r.res = "(($1).HEX3Astate < 0)" % [rdLoc(a)]
-  else:
-    gen(p, n, a)
-    r.res = "((($1.ClE_0).HEX3Astate) < 0)" % [rdLoc(a)]
-  r.kind = resExpr
-
 proc arithAux(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
  var
    x, y: TCompRes = default(TCompRes)
@@ -801,13 +788,7 @@ proc arithAux(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
  of mEqProc: applyFormat("($1 == $2)", "($1 == $2)")
  of mUnaryMinusI: applyFormat("negInt($1)", "-($1)")
  of mUnaryMinusI64: applyFormat("negInt64($1)", "-($1)")
-  of mAbsI:
-    let typ = n[1].typ.skipTypes(abstractVarRange)
-    if typ.kind == tyInt64 and optJsBigInt64 in p.config.globalOptions:
-      useMagic(p, "absInt64")
-      applyFormat("absInt64($1)", "absInt64($1)")
-    else:
-      applyFormat("absInt($1)", "Math.abs($1)")
+  of mAbsI: applyFormat("absInt($1)", "Math.abs($1)")
  of mNot: applyFormat("!($1)", "!($1)")
  of mUnaryPlusI: applyFormat("+($1)", "+($1)")
  of mBitnotI:
@@ -824,6 +805,8 @@ proc arithAux(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
  of mUnaryMinusF64: applyFormat("-($1)", "-($1)")
  of mCharToStr: applyFormat("nimCharToStr($1)", "nimCharToStr($1)")
  of mBoolToStr: applyFormat("nimBoolToStr($1)", "nimBoolToStr($1)")
+  of mIntToStr: applyFormat("cstrToNimstr(($1) + \"\")", "cstrToNimstr(($1) + \"\")")
+  of mInt64ToStr: applyFormat("cstrToNimstr(($1) + \"\")", "cstrToNimstr(($1) + \"\")")
  of mCStrToStr: applyFormat("cstrToNimstr($1)", "cstrToNimstr($1)")
  of mStrToStr, mUnown, mIsolate, mFinished: applyFormat("$1", "$1")
  else:
@@ -844,7 +827,7 @@ proc arith(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
    arithAux(p, n, r, op)
  of mModI:
    arithAux(p, n, r, op)
-  of mCharToStr, mBoolToStr, mCStrToStr, mStrToStr, mEnumToStr:
+  of mCharToStr, mBoolToStr, mIntToStr, mInt64ToStr, mCStrToStr, mStrToStr, mEnumToStr:
    arithAux(p, n, r, op)
  of mEqRef:
    if mapType(n[1].typ) != etyBaseIndex:
@@ -854,11 +837,6 @@ proc arith(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
      gen(p, n[1], x)
      gen(p, n[2], y)
      r.res = "($# == $# && $# == $#)" % [x.address, y.address, x.res, y.res]
-  of mEqProc:
-    if skipTypes(n[1].typ, abstractInst).callConv == ccClosure:
-      binaryExpr(p, n, r, "cmpClosures", "cmpClosures($1, $2)")
-    else:
-      arithAux(p, n, r, op)
  else:
    arithAux(p, n, r, op)
  r.kind = resExpr
@@ -948,7 +926,7 @@ proc genTry(p: PProc, n: PNode, r: var TCompRes) =
    p.body.add("++excHandler;\L")
  var tmpFramePtr = rope"F"
  lineF(p, "try {$n", [])
-  var a: TCompRes = default(TCompRes)
+  var a: TCompRes
  gen(p, n[0], a)
  moveInto(p, a, r)
  var generalCatchBranchExists = false
@@ -992,7 +970,7 @@ proc genTry(p: PProc, n: PNode, r: var TCompRes) =
        # if isJsObject(throwObj.typ):
        if isImportedException(throwObj.typ, p.config):
          orExpr.addf("lastJSError instanceof $1",
-            [throwObj.typ.sym.loc.snippet])
+            [throwObj.typ.sym.loc.r])
        else:
          orExpr.addf("isObj(lastJSError.m_type, $1)",
               [genTypeInfo(p, throwObj.typ)])
@@ -1002,8 +980,8 @@ proc genTry(p: PProc, n: PNode, r: var TCompRes) =
      # If some branch requires a local alias introduce it here. This is needed
      # since JS cannot do ``catch x as y``.
      if excAlias != nil:
-        excAlias.sym.loc.snippet = mangleName(p.module, excAlias.sym)
-        lineF(p, "var $1 = lastJSError;$n", excAlias.sym.loc.snippet)
+        excAlias.sym.loc.r = mangleName(p.module, excAlias.sym)
+        lineF(p, "var $1 = lastJSError;$n", excAlias.sym.loc.r)
      gen(p, n[i][^1], a)
      moveInto(p, a, r)
      lineF(p, "}$n", [])
@@ -1041,7 +1019,7 @@ proc genCaseJS(p: PProc, n: PNode, r: var TCompRes) =
    a, b, cond, stmt: TCompRes = default(TCompRes)
  genLineDir(p, n)
  gen(p, n[0], cond)
-  let typeKind = skipTypes(n[0].typ, abstractVar+{tyRange}).kind
+  let typeKind = skipTypes(n[0].typ, abstractVar).kind
  var transferRange = false
  let anyString = typeKind in {tyString, tyCstring}
  case typeKind
@@ -1109,19 +1087,14 @@ proc genCaseJS(p: PProc, n: PNode, r: var TCompRes) =
          lineF(p, "break;$n", [])
    of nkElse:
      if transferRange:
-        if n.len == 2: # a dangling else for a case statement
-          transferRange = false
-          lineF(p, "switch ($1) {$n", [cond.rdLoc])
-          lineF(p, "default: $n", [])
-        else:
-          lineF(p, "else{$n", [])
+         lineF(p, "else{$n", [])
      else:
        lineF(p, "default: $n", [])
      p.nested:
        gen(p, it[0], stmt)
        moveInto(p, stmt, r)
        if transferRange:
-          lineF(p, "}$n", [])
+           lineF(p, "}$n", [])
        else:
          lineF(p, "break;$n", [])
    else: internalError(p.config, it.info, "jsgen.genCaseStmt")
@@ -1163,14 +1136,10 @@ proc genBreakStmt(p: PProc, n: PNode) =
  p.blocks[idx].id = abs(p.blocks[idx].id) # label is used
  lineF(p, "break Label$1;$n", [rope(p.blocks[idx].id)])

-proc genAsmOrEmitStmt(p: PProc, n: PNode; isAsmStmt = false) =
+proc genAsmOrEmitStmt(p: PProc, n: PNode) =
  genLineDir(p, n)
  p.body.add p.indentLine("")
-  let offset =
-    if isAsmStmt: 1 # first son is pragmas
-    else: 0
-
-  for i in offset..<n.len:
+  for i in 0..<n.len:
    let it = n[i]
    case it.kind
    of nkStrLit..nkTripleStrLit:
@@ -1225,17 +1194,8 @@ proc genIf(p: PProc, n: PNode, r: var TCompRes) =
    lineF(p, "}$n", [])
  line(p, repeat('}', toClose) & "\L")

-proc generateHeader(p: PProc, prc: PSym): Rope =
+proc generateHeader(p: PProc, typ: PType): Rope =
  result = ""
-  let typ = prc.typ
-  if jsNoLambdaLifting notin p.config.legacyFeatures:
-    if typ.callConv == ccClosure:
-      # we treat Env as the `this` parameter of the function
-      # to keep it simple
-      let env = prc.ast[paramsPos].lastSon
-      assert env.kind == nkSym, "env is missing"
-      env.sym.loc.snippet = "this"
-
  for i in 1..<typ.n.len:
    assert(typ.n[i].kind == nkSym)
    var param = typ.n[i].sym
@@ -1268,10 +1228,9 @@ const

 proc needsNoCopy(p: PProc; y: PNode): bool =
  return y.kind in nodeKindsNeedNoCopy or
-        ((mapType(y.typ) != etyBaseIndex or
-          (jsNoLambdaLifting in p.config.legacyFeatures and y.kind == nkSym and y.sym.kind == skParam)) and
+        ((mapType(y.typ) != etyBaseIndex or (y.kind == nkSym and y.sym.kind == skParam)) and
          (skipTypes(y.typ, abstractInst).kind in
-            {tyRef, tyPtr, tyLent, tyVar, tyCstring, tyProc, tyOwned, tyOpenArray} + IntegralTypes))
+            {tyRef, tyPtr, tyLent, tyVar, tyCstring, tyProc, tyOwned} + IntegralTypes))

 proc genAsgnAux(p: PProc, x, y: PNode, noCopyNeeded: bool) =
  var a, b: TCompRes = default(TCompRes)
@@ -1298,7 +1257,7 @@ proc genAsgnAux(p: PProc, x, y: PNode, noCopyNeeded: bool) =
      lineF(p, "$1 = nimCopy(null, $2, $3);$n",
               [a.rdLoc, b.res, genTypeInfo(p, y.typ)])
  of etyObject:
-    if x.typ.kind in {tyVar, tyLent, tyOpenArray, tyVarargs} or (needsNoCopy(p, y) and needsNoCopy(p, x)) or noCopyNeeded:
+    if x.typ.kind in {tyVar, tyLent} or (needsNoCopy(p, y) and needsNoCopy(p, x)) or noCopyNeeded:
      lineF(p, "$1 = $2;$n", [a.rdLoc, b.rdLoc])
    else:
      useMagic(p, "nimCopy")
@@ -1353,10 +1312,19 @@ proc genFastAsgn(p: PProc, n: PNode) =
  genAsgnAux(p, n[0], n[1], noCopyNeeded=noCopy)

 proc genSwap(p: PProc, n: PNode) =
-  let stmtList = lowerSwap(p.module.graph, n, p.module.idgen, if p.prc != nil: p.prc else: p.module.module)
-  assert stmtList.kind == nkStmtList
-  for i in 0..<stmtList.len:
-    genStmt(p, stmtList[i])
+  var a, b: TCompRes = default(TCompRes)
+  gen(p, n[1], a)
+  gen(p, n[2], b)
+  var tmp = p.getTemp(false)
+  if mapType(p, skipTypes(n[1].typ, abstractVar)) == etyBaseIndex:
+    let tmp2 = p.getTemp(false)
+    if a.typ != etyBaseIndex or b.typ != etyBaseIndex:
+      internalError(p.config, n.info, "genSwap")
+    lineF(p, "var $1 = $2; $2 = $3; $3 = $1;$n",
+             [tmp, a.address, b.address])
+    tmp = tmp2
+  lineF(p, "var $1 = $2; $2 = $3; $3 = $1;",
+           [tmp, a.res, b.res])

 proc getFieldPosition(p: PProc; f: PNode): int =
  case f.kind
@@ -1376,8 +1344,8 @@ proc genFieldAddr(p: PProc, n: PNode, r: var TCompRes) =
  else:
    if b[1].kind != nkSym: internalError(p.config, b[1].info, "genFieldAddr")
    var f = b[1].sym
-    if f.loc.snippet == "": f.loc.snippet = mangleName(p.module, f)
-    r.res = makeJSString($f.loc.snippet)
+    if f.loc.r == "": f.loc.r = mangleName(p.module, f)
+    r.res = makeJSString($f.loc.r)
  internalAssert p.config, a.typ != etyBaseIndex
  r.address = a.res
  r.kind = resExpr
@@ -1404,8 +1372,8 @@ proc genFieldAccess(p: PProc, n: PNode, r: var TCompRes) =
  else:
    if n[1].kind != nkSym: internalError(p.config, n[1].info, "genFieldAccess")
    var f = n[1].sym
-    if f.loc.snippet == "": f.loc.snippet = mangleName(p.module, f)
-    r.res = "$1.$2" % [r.res, f.loc.snippet]
+    if f.loc.r == "": f.loc.r = mangleName(p.module, f)
+    r.res = "$1.$2" % [r.res, f.loc.r]
    mkTemp(1)
  r.kind = resExpr

@@ -1425,11 +1393,11 @@ proc genCheckedFieldOp(p: PProc, n: PNode, addrTyp: PType, r: var TCompRes) =
  # Field symbol
  var field = accessExpr[1].sym
  internalAssert p.config, field.kind == skField
-  if field.loc.snippet == "": field.loc.snippet = mangleName(p.module, field)
+  if field.loc.r == "": field.loc.r = mangleName(p.module, field)
  # Discriminant symbol
  let disc = checkExpr[2].sym
  internalAssert p.config, disc.kind == skField
-  if disc.loc.snippet == "": disc.loc.snippet = mangleName(p.module, disc)
+  if disc.loc.r == "": disc.loc.r = mangleName(p.module, disc)

  var setx: TCompRes = default(TCompRes)
  gen(p, checkExpr[1], setx)
@@ -1446,16 +1414,16 @@ proc genCheckedFieldOp(p: PProc, n: PNode, addrTyp: PType, r: var TCompRes) =
  useMagic(p, "reprDiscriminant") # no need to offset by firstOrd unlike for cgen
  let msg = genFieldDefect(p.config, field.name.s, disc)
  lineF(p, "if ($1[$2.$3]$4undefined) { raiseFieldError2(makeNimstrLit($5), reprDiscriminant($2.$3, $6)); }$n",
-    setx.res, tmp, disc.loc.snippet, if negCheck: "!==" else: "===",
+    setx.res, tmp, disc.loc.r, if negCheck: "!==" else: "===",
    makeJSString(msg), genTypeInfo(p, disc.typ))

  if addrTyp != nil and mapType(p, addrTyp) == etyBaseIndex:
    r.typ = etyBaseIndex
-    r.res = makeJSString($field.loc.snippet)
+    r.res = makeJSString($field.loc.r)
    r.address = tmp
  else:
    r.typ = etyNone
-    r.res = "$1.$2" % [tmp, field.loc.snippet]
+    r.res = "$1.$2" % [tmp, field.loc.r]
  r.kind = resExpr

 proc genArrayAddr(p: PProc, n: PNode, r: var TCompRes) =
@@ -1471,7 +1439,7 @@ proc genArrayAddr(p: PProc, n: PNode, r: var TCompRes) =
  r.address = x
  var typ = skipTypes(m[0].typ, abstractPtrs)
  if typ.kind == tyArray:
-    first = firstOrd(p.config, typ.indexType)
+    first = firstOrd(p.config, typ[0])
  if optBoundsCheck in p.options:
    useMagic(p, "chckIndx")
    if first == 0: # save a couple chars
@@ -1486,8 +1454,8 @@ proc genArrayAddr(p: PProc, n: PNode, r: var TCompRes) =
  r.kind = resExpr

 proc genArrayAccess(p: PProc, n: PNode, r: var TCompRes) =
-  var ty = skipTypes(n[0].typ, abstractVarRange+tyUserTypeClasses)
-  if ty.kind in {tyRef, tyPtr, tyLent, tyOwned}: ty = skipTypes(ty.elementType, abstractVarRange)
+  var ty = skipTypes(n[0].typ, abstractVarRange)
+  if ty.kind in {tyRef, tyPtr, tyLent, tyOwned}: ty = skipTypes(ty.lastSon, abstractVarRange)
  case ty.kind
  of tyArray, tyOpenArray, tySequence, tyString, tyCstring, tyVarargs:
    genArrayAddr(p, n, r)
@@ -1522,10 +1490,10 @@ template isIndirect(x: PSym): bool =

 proc genSymAddr(p: PProc, n: PNode, typ: PType, r: var TCompRes) =
  let s = n.sym
-  if s.loc.snippet == "": internalError(p.config, n.info, "genAddr: 3")
+  if s.loc.r == "": internalError(p.config, n.info, "genAddr: 3")
  case s.kind
  of skParam:
-    r.res = s.loc.snippet
+    r.res = s.loc.r
    r.address = ""
    r.typ = etyNone
  of skVar, skLet, skResult:
@@ -1539,15 +1507,15 @@ proc genSymAddr(p: PProc, n: PNode, typ: PType, r: var TCompRes) =
      # make addr() a no-op:
      r.typ = etyNone
      if isIndirect(s):
-        r.res = s.loc.snippet & "[0]"
+        r.res = s.loc.r & "[0]"
      else:
-        r.res = s.loc.snippet
+        r.res = s.loc.r
      r.address = ""
    elif {sfGlobal, sfAddrTaken} * s.flags != {} or jsType == etyBaseIndex:
      # for ease of code generation, we do not distinguish between
      # sfAddrTaken and sfGlobal.
      r.typ = etyBaseIndex
-      r.address = s.loc.snippet
+      r.address = s.loc.r
      r.res = rope("0")
    else:
      # 'var openArray' for instance produces an 'addr' but this is harmless:
@@ -1574,7 +1542,7 @@ proc genAddr(p: PProc, n: PNode, r: var TCompRes) =
      if ty.kind in MappedToObject:
        gen(p, n[0], r)
      else:
-        let kindOfIndexedExpr = skipTypes(n[0][0].typ, abstractVarRange+tyUserTypeClasses).kind
+        let kindOfIndexedExpr = skipTypes(n[0][0].typ, abstractVarRange).kind
        case kindOfIndexedExpr
        of tyArray, tyOpenArray, tySequence, tyString, tyCstring, tyVarargs:
          genArrayAddr(p, n[0], r)
@@ -1585,8 +1553,15 @@ proc genAddr(p: PProc, n: PNode, r: var TCompRes) =
        else: internalError(p.config, n[0].info, "expr(nkBracketExpr, " & $kindOfIndexedExpr & ')')
    of nkObjDownConv:
      gen(p, n[0], r)
-    of nkHiddenDeref, nkDerefExpr:
+    of nkHiddenDeref:
      gen(p, n[0], r)
+    of nkDerefExpr:
+      var x = n[0]
+      if n.kind == nkHiddenAddr:
+        x = n[0][0]
+        if n.typ.skipTypes(abstractVar).kind != tyOpenArray:
+          x.typ = n.typ
+      gen(p, x, r)
    of nkHiddenAddr:
      gen(p, n[0], r)
    of nkConv:
@@ -1613,15 +1588,12 @@ proc attachProc(p: PProc; s: PSym) =

 proc genProcForSymIfNeeded(p: PProc, s: PSym) =
  if not p.g.generatedSyms.containsOrIncl(s.id):
-    if jsNoLambdaLifting in p.config.legacyFeatures:
-      let newp = genProc(p, s)
-      var owner = p
-      while owner != nil and owner.prc != s.owner:
-        owner = owner.up
-      if owner != nil: owner.locals.add(newp)
-      else: attachProc(p, newp, s)
-    else:
-      attachProc(p, s)
+    let newp = genProc(p, s)
+    var owner = p
+    while owner != nil and owner.prc != s.owner:
+      owner = owner.up
+    if owner != nil: owner.locals.add(newp)
+    else: attachProc(p, newp, s)

 proc genCopyForParamIfNeeded(p: PProc, n: PNode) =
  let s = n.sym
@@ -1633,7 +1605,7 @@ proc genCopyForParamIfNeeded(p: PProc, n: PNode) =
      internalError(p.config, n.info, "couldn't find the owner proc of the closed over param: " & s.name.s)
    if owner.prc == s.owner:
      if not owner.generatedParamCopies.containsOrIncl(s.id):
-        let copy = "$1 = nimCopy(null, $1, $2);$n" % [s.loc.snippet, genTypeInfo(p, s.typ)]
+        let copy = "$1 = nimCopy(null, $1, $2);$n" % [s.loc.r, genTypeInfo(p, s.typ)]
        owner.locals.add(owner.indentLine(copy))
      return
    owner = owner.up
@@ -1644,40 +1616,40 @@ proc genSym(p: PProc, n: PNode, r: var TCompRes) =
  var s = n.sym
  case s.kind
  of skVar, skLet, skParam, skTemp, skResult, skForVar:
-    if s.loc.snippet == "":
+    if s.loc.r == "":
      internalError(p.config, n.info, "symbol has no generated name: " & s.name.s)
    if sfCompileTime in s.flags:
      genVarInit(p, s, if s.astdef != nil: s.astdef else: newNodeI(nkEmpty, s.info))
-    if jsNoLambdaLifting in p.config.legacyFeatures and s.kind == skParam:
+    if s.kind == skParam:
      genCopyForParamIfNeeded(p, n)
    let k = mapType(p, s.typ)
    if k == etyBaseIndex:
      r.typ = etyBaseIndex
      if {sfAddrTaken, sfGlobal} * s.flags != {}:
        if isIndirect(s):
-          r.address = "$1[0][0]" % [s.loc.snippet]
-          r.res = "$1[0][1]" % [s.loc.snippet]
+          r.address = "$1[0][0]" % [s.loc.r]
+          r.res = "$1[0][1]" % [s.loc.r]
        else:
-          r.address = "$1[0]" % [s.loc.snippet]
-          r.res = "$1[1]" % [s.loc.snippet]
+          r.address = "$1[0]" % [s.loc.r]
+          r.res = "$1[1]" % [s.loc.r]
      else:
-        r.address = s.loc.snippet
-        r.res = s.loc.snippet & "_Idx"
+        r.address = s.loc.r
+        r.res = s.loc.r & "_Idx"
    elif isIndirect(s):
-      r.res = "$1[0]" % [s.loc.snippet]
+      r.res = "$1[0]" % [s.loc.r]
    else:
-      r.res = s.loc.snippet
+      r.res = s.loc.r
  of skConst:
    genConstant(p, s)
-    if s.loc.snippet == "":
+    if s.loc.r == "":
      internalError(p.config, n.info, "symbol has no generated name: " & s.name.s)
-    r.res = s.loc.snippet
-  of skProc, skFunc, skConverter, skMethod, skIterator:
+    r.res = s.loc.r
+  of skProc, skFunc, skConverter, skMethod:
    if sfCompileTime in s.flags:
      localError(p.config, n.info, "request to generate code for .compileTime proc: " &
          s.name.s)
    discard mangleName(p.module, s)
-    r.res = s.loc.snippet
+    r.res = s.loc.r
    if lfNoDecl in s.loc.flags or s.magic notin generatedMagics or
       {sfImportc, sfInfixCall} * s.flags != {}:
      discard
@@ -1689,13 +1661,13 @@ proc genSym(p: PProc, n: PNode, r: var TCompRes) =
    else:
      genProcForSymIfNeeded(p, s)
  else:
-    if s.loc.snippet == "":
+    if s.loc.r == "":
      internalError(p.config, n.info, "symbol has no generated name: " & s.name.s)
    if mapType(p, s.typ) == etyBaseIndex:
-      r.address = s.loc.snippet
-      r.res = s.loc.snippet & "_Idx"
+      r.address = s.loc.r
+      r.res = s.loc.r & "_Idx"
    else:
-      r.res = s.loc.snippet
+      r.res = s.loc.r
  r.kind = resVal

 proc genDeref(p: PProc, n: PNode, r: var TCompRes) =
@@ -1837,9 +1809,9 @@ proc genPatternCall(p: PProc; n: PNode; pat: string; typ: PType;
 proc genInfixCall(p: PProc, n: PNode, r: var TCompRes) =
  # don't call '$' here for efficiency:
  let f = n[0].sym
-  if f.loc.snippet == "": f.loc.snippet = mangleName(p.module, f)
+  if f.loc.r == "": f.loc.r = mangleName(p.module, f)
  if sfInfixCall in f.flags:
-    let pat = $n[0].sym.loc.snippet
+    let pat = $n[0].sym.loc.r
    internalAssert p.config, pat.len > 0
    if pat.contains({'#', '(', '@'}):
      var typ = skipTypes(n[0].typ, abstractInst)
@@ -1917,7 +1889,7 @@ proc createObjInitList(p: PProc, typ: PType, excludedFieldIDs: IntSet, output: v
  while t != nil:
    t = t.skipTypes(skipPtrs)
    createRecordVarAux(p, t.n, excludedFieldIDs, output)
-    t = t.baseClass
+    t = t[0]

 proc arrayTypeForElemType(conf: ConfigRef; typ: PType): string =
  let typ = typ.skipTypes(abstractRange)
@@ -1954,7 +1926,7 @@ proc createVar(p: PProc, typ: PType, indirect: bool): Rope =
  of tyInt8..tyInt32, tyUInt8..tyUInt32, tyEnum, tyChar:
    result = putToSeq("0", indirect)
  of tyInt, tyUInt:
-    if $t.sym.loc.snippet == "bigint":
+    if $t.sym.loc.r == "bigint":
      result = putToSeq("0n", indirect)
    else:
      result = putToSeq("0", indirect)
@@ -1966,7 +1938,7 @@ proc createVar(p: PProc, typ: PType, indirect: bool): Rope =
  of tyFloat..tyFloat128:
    result = putToSeq("0.0", indirect)
  of tyRange, tyGenericInst, tyAlias, tySink, tyOwned, tyLent:
-    result = createVar(p, skipModifier(typ), indirect)
+    result = createVar(p, lastSon(typ), indirect)
  of tySet:
    result = putToSeq("{}", indirect)
  of tyBool:
@@ -2014,11 +1986,11 @@ proc createVar(p: PProc, typ: PType, indirect: bool): Rope =
      result = putToSeq("null", indirect)
  of tySequence, tyString:
    result = putToSeq("[]", indirect)
-  of tyCstring, tyProc, tyOpenArray:
+  of tyCstring, tyProc:
    result = putToSeq("null", indirect)
  of tyStatic:
    if t.n != nil:
-      result = createVar(p, skipModifier t, indirect)
+      result = createVar(p, lastSon t, indirect)
    else:
      internalError(p.config, "createVar: " & $t.kind)
      result = ""
@@ -2066,7 +2038,7 @@ proc genVarInit(p: PProc, v: PSym, n: PNode) =
    gen(p, n, a)
    case mapType(p, v.typ)
    of etyObject, etySeq:
-      if v.typ.kind in {tyOpenArray, tyVarargs} or needsNoCopy(p, n):
+      if needsNoCopy(p, n):
        s = a.res
      else:
        useMagic(p, "nimCopy")
@@ -2076,44 +2048,33 @@ proc genVarInit(p: PProc, v: PSym, n: PNode) =
      if a.typ == etyBaseIndex:
        if targetBaseIndex:
          line(p, runtimeFormat(varCode & " = $3, $2_Idx = $4;$n",
-                   [returnType, v.loc.snippet, a.address, a.res]))
+                   [returnType, v.loc.r, a.address, a.res]))
        else:
          if isIndirect(v):
            line(p, runtimeFormat(varCode & " = [[$3, $4]];$n",
-                     [returnType, v.loc.snippet, a.address, a.res]))
+                     [returnType, v.loc.r, a.address, a.res]))
          else:
            line(p, runtimeFormat(varCode & " = [$3, $4];$n",
-                     [returnType, v.loc.snippet, a.address, a.res]))
+                     [returnType, v.loc.r, a.address, a.res]))
      else:
        if targetBaseIndex:
          let tmp = p.getTemp
          lineF(p, "var $1 = $2, $3 = $1[0], $3_Idx = $1[1];$n",
-                   [tmp, a.res, v.loc.snippet])
+                   [tmp, a.res, v.loc.r])
        else:
-          line(p, runtimeFormat(varCode & " = $3;$n", [returnType, v.loc.snippet, a.res]))
+          line(p, runtimeFormat(varCode & " = $3;$n", [returnType, v.loc.r, a.res]))
      return
    else:
      s = a.res
    if isIndirect(v):
-      line(p, runtimeFormat(varCode & " = [$3];$n", [returnType, v.loc.snippet, s]))
+      line(p, runtimeFormat(varCode & " = [$3];$n", [returnType, v.loc.r, s]))
    else:
-      line(p, runtimeFormat(varCode & " = $3;$n", [returnType, v.loc.snippet, s]))
+      line(p, runtimeFormat(varCode & " = $3;$n", [returnType, v.loc.r, s]))

  if useReloadingGuard or useGlobalPragmas:
    dec p.extraIndent
    lineF(p, "}$n")

-proc genClosureVar(p: PProc, n: PNode) =
-  # assert n[2].kind != nkEmpty
-  # TODO: fixme transform `var env.x` into `var env.x = default()` after
-  # the order of transf and lambdalifting is fixed
-  if n[2].kind != nkEmpty:
-    genAsgnAux(p, n[0], n[2], false)
-  else:
-    var a: TCompRes = default(TCompRes)
-    gen(p, n[0], a)
-    line(p, runtimeFormat("$1 = $2;$n", [rdLoc(a), createVar(p, n[0].typ, false)]))
-
 proc genVarStmt(p: PProc, n: PNode) =
  for i in 0..<n.len:
    var a = n[i]
@@ -2123,17 +2084,15 @@ proc genVarStmt(p: PProc, n: PNode) =
        genStmt(p, unpacked)
      else:
        assert(a.kind == nkIdentDefs)
-        if a[0].kind == nkSym:
-          var v = a[0].sym
-          if lfNoDecl notin v.loc.flags and sfImportc notin v.flags:
-            genLineDir(p, a)
-            if sfCompileTime notin v.flags:
-              genVarInit(p, v, a[2])
-            else:
-              # lazy emit, done when it's actually used.
-              if v.ast == nil: v.ast = a[2]
-        else: # closure
-          genClosureVar(p, a)
+        assert(a[0].kind == nkSym)
+        var v = a[0].sym
+        if lfNoDecl notin v.loc.flags and sfImportc notin v.flags:
+          genLineDir(p, a)
+          if sfCompileTime notin v.flags:
+            genVarInit(p, v, a[2])
+          else:
+            # lazy emit, done when it's actually used.
+            if v.ast == nil: v.ast = a[2]

 proc genConstant(p: PProc, c: PSym) =
  if lfNoDecl notin c.loc.flags and not p.g.generatedSyms.containsOrIncl(c.id):
@@ -2180,20 +2139,20 @@ proc genConStrStr(p: PProc, n: PNode, r: var TCompRes) =
  if skipTypes(n[1].typ, abstractVarRange).kind == tyChar:
    r.res.add("[$1].concat(" % [a.res])
  else:
-    r.res.add("($1).concat(" % [a.res])
+    r.res.add("($1 || []).concat(" % [a.res])

  for i in 2..<n.len - 1:
    gen(p, n[i], a)
    if skipTypes(n[i].typ, abstractVarRange).kind == tyChar:
      r.res.add("[$1]," % [a.res])
    else:
-      r.res.add("$1," % [a.res])
+      r.res.add("$1 || []," % [a.res])

  gen(p, n[^1], a)
  if skipTypes(n[^1].typ, abstractVarRange).kind == tyChar:
    r.res.add("[$1])" % [a.res])
  else:
-    r.res.add("$1)" % [a.res])
+    r.res.add("$1 || [])" % [a.res])

 proc genReprAux(p: PProc, n: PNode, r: var TCompRes, magic: string, typ: Rope = "") =
  useMagic(p, magic)
@@ -2260,17 +2219,16 @@ proc genDefault(p: PProc, n: PNode; r: var TCompRes) =
  r.res = createVar(p, n.typ, indirect = false)
  r.kind = resExpr

-proc genWasMoved(p: PProc, n: PNode) =
-  # TODO: it should be done by nir
+proc genReset(p: PProc, n: PNode) =
  var x: TCompRes = default(TCompRes)
+  useMagic(p, "genericReset")
  gen(p, n[1], x)
  if x.typ == etyBaseIndex:
    lineF(p, "$1 = null, $2 = 0;$n", [x.address, x.res])
  else:
-    var y: TCompRes = default(TCompRes)
-    genDefault(p, n[1], y)
-    let (a, _) = maybeMakeTempAssignable(p, n[1], x)
-    lineF(p, "$1 = $2;$n", [a, y.rdLoc])
+    let (a, tmp) = maybeMakeTempAssignable(p, n[1], x)
+    lineF(p, "$1 = genericReset($3, $2);$n", [a,
+                  genTypeInfo(p, n[1].typ), tmp])

 proc genMove(p: PProc; n: PNode; r: var TCompRes) =
  var a: TCompRes = default(TCompRes)
@@ -2278,7 +2236,7 @@ proc genMove(p: PProc; n: PNode; r: var TCompRes) =
  r.res = p.getTemp()
  gen(p, n[1], a)
  lineF(p, "$1 = $2;$n", [r.rdLoc, a.rdLoc])
-  genWasMoved(p, n)
+  genReset(p, n)
  #lineF(p, "$1 = $2;$n", [dest.rdLoc, src.rdLoc])

 proc genDup(p: PProc; n: PNode; r: var TCompRes) =
@@ -2451,7 +2409,6 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
  of mMulSet: binaryExpr(p, n, r, "SetMul", "SetMul($1, $2)")
  of mPlusSet: binaryExpr(p, n, r, "SetPlus", "SetPlus($1, $2)")
  of mMinusSet: binaryExpr(p, n, r, "SetMinus", "SetMinus($1, $2)")
-  of mXorSet: binaryExpr(p, n, r, "SetXor", "SetXor($1, $2)")
  of mIncl: binaryExpr(p, n, r, "", "$1[$2] = true")
  of mExcl: binaryExpr(p, n, r, "", "delete $1[$2]")
  of mInSet:
@@ -2460,7 +2417,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
  of mNewSeqOfCap: unaryExpr(p, n, r, "", "[]")
  of mOf: genOf(p, n, r)
  of mDefault, mZeroDefault: genDefault(p, n, r)
-  of mWasMoved: genWasMoved(p, n)
+  of mReset, mWasMoved: genReset(p, n)
  of mEcho: genEcho(p, n, r)
  of mNLen..mNError, mSlurp, mStaticExec:
    localError(p.config, n.info, errXMustBeCompileTime % n[0].sym.name.s)
@@ -2573,17 +2530,17 @@ proc genObjConstr(p: PProc, n: PNode, r: var TCompRes) =
    let val = it[1]
    gen(p, val, a)
    var f = it[0].sym
-    if f.loc.snippet == "": f.loc.snippet = mangleName(p.module, f)
+    if f.loc.r == "": f.loc.r = mangleName(p.module, f)
    fieldIDs.incl(lookupFieldAgain(n.typ.skipTypes({tyDistinct}), f).id)

    let typ = val.typ.skipTypes(abstractInst)
    if a.typ == etyBaseIndex:
-      initList.addf("$#: [$#, $#]", [f.loc.snippet, a.address, a.res])
+      initList.addf("$#: [$#, $#]", [f.loc.r, a.address, a.res])
    else:
      if not needsNoCopy(p, val):
        useMagic(p, "nimCopy")
        a.res = "nimCopy(null, $1, $2)" % [a.rdLoc, genTypeInfo(p, typ)]
-      initList.addf("$#: $#", [f.loc.snippet, a.res])
+      initList.addf("$#: $#", [f.loc.r, a.res])
  let t = skipTypes(n.typ, abstractInst + skipPtrs)
  createObjInitList(p, t, fieldIDs, initList)
  r.res = ("{$1}") % [initList]
@@ -2642,13 +2599,7 @@ proc genRangeChck(p: PProc, n: PNode, r: var TCompRes, magic: string) =
  let src = skipTypes(n[0].typ, abstractVarRange)
  let dest = skipTypes(n.typ, abstractVarRange)
  if optRangeCheck notin p.options:
-    if optJsBigInt64 in p.config.globalOptions and
-          dest.kind in {tyUInt..tyUInt32, tyInt..tyInt32} and
-          src.kind in {tyInt64, tyUInt64}:
-      # conversions to Number are kept
-      r.res = "Number($1)" % [r.res]
-    else:
-      discard
+    return
  elif dest.kind in {tyUInt..tyUInt64} and checkUnsignedConversions notin p.config.legacyFeatures:
    if src.kind in {tyInt64, tyUInt64} and optJsBigInt64 in p.config.globalOptions:
      r.res = "BigInt.asUintN($1, $2)" % [$(dest.size * 8), r.res]
@@ -2747,8 +2698,8 @@ proc genProc(oldProc: PProc, prc: PSym): Rope =
  var returnStmt: Rope = ""
  var resultAsgn: Rope = ""
  var name = mangleName(p.module, prc)
-  let header = generateHeader(p, prc)
-  if prc.typ.returnType != nil and sfPure notin prc.flags:
+  let header = generateHeader(p, prc.typ)
+  if prc.typ[0] != nil and sfPure notin prc.flags:
    resultSym = prc.ast[resultPos].sym
    let mname = mangleName(p.module, resultSym)
    # otherwise uses "fat pointers"
@@ -2829,9 +2780,9 @@ proc genPragma(p: PProc, n: PNode) =
    case whichPragma(it)
    of wEmit: genAsmOrEmitStmt(p, it[1])
    of wPush:
-      processPushBackendOption(p.config, p.optionsStack, p.options, n, i+1)
+      processPushBackendOption(p.optionsStack, p.options, n, i+1)
    of wPop:
-      processPopBackendOption(p.config, p.optionsStack, p.options)
+      processPopBackendOption(p.optionsStack, p.options)
    else: discard

 proc genCast(p: PProc, n: PNode, r: var TCompRes) =
@@ -2966,18 +2917,7 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
      genInfixCall(p, n, r)
    else:
      genCall(p, n, r)
-  of nkClosure:
-    if jsNoLambdaLifting in p.config.legacyFeatures:
-      gen(p, n[0], r)
-    else:
-      let tmp = getTemp(p)
-      var a: TCompRes = default(TCompRes)
-      var b: TCompRes = default(TCompRes)
-      gen(p, n[0], a)
-      gen(p, n[1], b)
-      lineF(p, "$1 = $2.bind($3); $1.ClP_0 = $2; $1.ClE_0 = $3;$n", [tmp, a.rdLoc, b.rdLoc])
-      r.res = tmp
-      r.kind = resVal
+  of nkClosure: gen(p, n[0], r)
  of nkCurly: genSetConstr(p, n, r)
  of nkBracket: genArrayConstr(p, n, r)
  of nkPar, nkTupleConstr: genTupleConstr(p, n, r)
@@ -3008,7 +2948,7 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
  of nkLambdaKinds:
    let s = n[namePos].sym
    discard mangleName(p.module, s)
-    r.res = s.loc.snippet
+    r.res = s.loc.r
    if lfNoDecl in s.loc.flags or s.magic notin generatedMagics: discard
    elif not p.g.generatedSyms.containsOrIncl(s.id):
      p.locals.add(genProc(p, s))
@@ -3040,16 +2980,17 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
    if n[0].kind != nkEmpty:
      genLineDir(p, n)
      gen(p, n[0], r)
-      r.res = "(" & r.res & ")"
-  of nkAsmStmt:
-    warningDeprecated(p.config, n.info, "'asm' for the JS target is deprecated, use the 'emit' pragma")
-    genAsmOrEmitStmt(p, n, true)
+      r.res = "var _ = " & r.res
+  of nkAsmStmt: genAsmOrEmitStmt(p, n)
  of nkTryStmt, nkHiddenTryStmt: genTry(p, n, r)
  of nkRaiseStmt: genRaiseStmt(p, n)
  of nkTypeSection, nkCommentStmt, nkIncludeStmt,
     nkImportStmt, nkImportExceptStmt, nkExportStmt, nkExportExceptStmt,
-     nkFromStmt, nkTemplateDef, nkMacroDef, nkIteratorDef, nkStaticStmt,
+     nkFromStmt, nkTemplateDef, nkMacroDef, nkStaticStmt,
     nkMixinStmt, nkBindStmt: discard
+  of nkIteratorDef:
+    if n[0].sym.typ.callConv == TCallingConvention.ccClosure:
+      globalError(p.config, n.info, "Closure iterators are not supported by JS backend!")
  of nkPragma: genPragma(p, n)
  of nkProcDef, nkFuncDef, nkMethodDef, nkConverterDef:
    var s = n[namePos].sym
@@ -3057,9 +2998,7 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
      genSym(p, n[namePos], r)
      r.res = ""
  of nkGotoState, nkState:
-    globalError(p.config, n.info, "not implemented")
-  of nkBreakState:
-    genBreakState(p, n[0], r)
+    globalError(p.config, n.info, "First class iterators not implemented")
  of nkPragmaBlock: gen(p, n.lastSon, r)
  of nkComesFrom:
    discard "XXX to implement for better stack traces"
@@ -3166,6 +3105,15 @@ proc wholeCode(graph: ModuleGraph; m: BModule): Rope =

  result = globals.typeInfo & globals.constants & globals.code

+proc getClassName(t: PType): Rope =
+  var s = t.sym
+  if s.isNil or sfAnon in s.flags:
+    s = skipTypes(t, abstractPtrs).sym
+  if s.isNil or sfAnon in s.flags:
+    doAssert(false, "cannot retrieve class name")
+  if s.loc.r != "": result = s.loc.r
+  else: result = rope(s.name.s)
+
 proc finalJSCodeGen*(graph: ModuleGraph; b: PPassContext, n: PNode): PNode =
  ## Finalize JS code generation of a Nim module.
  ## Param `n` may contain nodes returned from the last module close call.
--- a/compiler/jstypes.nim
+++ b/compiler/jstypes.nim
@@ -69,7 +69,7 @@ proc genObjectFields(p: PProc, typ: PType, n: PNode): Rope =
  else: internalError(p.config, n.info, "genObjectFields")

 proc objHasTypeField(t: PType): bool {.inline.} =
-  tfInheritable in t.flags or t.baseClass != nil
+  tfInheritable in t.flags or t[0] != nil

 proc genObjectInfo(p: PProc, typ: PType, name: Rope) =
  let kind = if objHasTypeField(typ): tyObject else: tyTuple
@@ -79,9 +79,9 @@ proc genObjectInfo(p: PProc, typ: PType, name: Rope) =
  p.g.typeInfo.addf("var NNI$1 = $2;$n",
       [rope(typ.id), genObjectFields(p, typ, typ.n)])
  p.g.typeInfo.addf("$1.node = NNI$2;$n", [name, rope(typ.id)])
-  if (typ.kind == tyObject) and (typ.baseClass != nil):
+  if (typ.kind == tyObject) and (typ[0] != nil):
    p.g.typeInfo.addf("$1.base = $2;$n",
-         [name, genTypeInfo(p, typ.baseClass.skipTypes(skipPtrs))])
+         [name, genTypeInfo(p, typ[0].skipTypes(skipPtrs))])

 proc genTupleFields(p: PProc, typ: PType): Rope =
  var s: Rope = ""
@@ -117,9 +117,9 @@ proc genEnumInfo(p: PProc, typ: PType, name: Rope) =
  prepend(p.g.typeInfo, s)
  p.g.typeInfo.add(n)
  p.g.typeInfo.addf("$1.node = NNI$2;$n", [name, rope(typ.id)])
-  if typ.baseClass != nil:
+  if typ[0] != nil:
    p.g.typeInfo.addf("$1.base = $2;$n",
-         [name, genTypeInfo(p, typ.baseClass)])
+         [name, genTypeInfo(p, typ[0])])

 proc genTypeInfo(p: PProc, typ: PType): Rope =
  let t = typ.skipTypes({tyGenericInst, tyDistinct, tyAlias, tySink, tyOwned})
@@ -127,7 +127,7 @@ proc genTypeInfo(p: PProc, typ: PType): Rope =
  if containsOrIncl(p.g.typeInfoGenerated, t.id): return
  case t.kind
  of tyDistinct:
-    result = genTypeInfo(p, t.skipModifier)
+    result = genTypeInfo(p, t[0])
  of tyPointer, tyProc, tyBool, tyChar, tyCstring, tyString, tyInt..tyUInt64:
    var s =
      "var $1 = {size: 0,kind: $2,base: null,node: null,finalizer: null};$n" %
@@ -139,18 +139,18 @@ proc genTypeInfo(p: PProc, typ: PType): Rope =
              [result, rope(ord(t.kind))]
    prepend(p.g.typeInfo, s)
    p.g.typeInfo.addf("$1.base = $2;$n",
-         [result, genTypeInfo(p, t.elementType)])
+         [result, genTypeInfo(p, t.lastSon)])
  of tyArray:
    var s =
      "var $1 = {size: 0, kind: $2, base: null, node: null, finalizer: null};$n" %
              [result, rope(ord(t.kind))]
    prepend(p.g.typeInfo, s)
    p.g.typeInfo.addf("$1.base = $2;$n",
-         [result, genTypeInfo(p, t.elementType)])
+         [result, genTypeInfo(p, t[1])])
  of tyEnum: genEnumInfo(p, t, result)
  of tyObject: genObjectInfo(p, t, result)
  of tyTuple: genTupleInfo(p, t, result)
  of tyStatic:
-    if t.n != nil: result = genTypeInfo(p, skipModifier t)
+    if t.n != nil: result = genTypeInfo(p, lastSon t)
    else: internalError(p.config, "genTypeInfo(" & $t.kind & ')')
  else: internalError(p.config, "genTypeInfo(" & $t.kind & ')')
--- a/compiler/lambdalifting.nim
+++ b/compiler/lambdalifting.nim
@@ -145,13 +145,11 @@ proc createStateField(g: ModuleGraph; iter: PSym; idgen: IdGenerator): PSym =
  result = newSym(skField, getIdent(g.cache, ":state"), idgen, iter, iter.info)
  result.typ = createClosureIterStateType(g, iter, idgen)

-template isIterator*(owner: PSym): bool =
-  owner.kind == skIterator and owner.typ.callConv == ccClosure
-
 proc createEnvObj(g: ModuleGraph; idgen: IdGenerator; owner: PSym; info: TLineInfo): PType =
+  # YYY meh, just add the state field for every closure for now, it's too
+  # hard to figure out if it comes from a closure iterator:
  result = createObj(g, idgen, owner, info, final=false)
-  if owner.isIterator:
-    rawAddField(result, createStateField(g, owner, idgen))
+  rawAddField(result, createStateField(g, owner, idgen))

 proc getClosureIterResult*(g: ModuleGraph; iter: PSym; idgen: IdGenerator): PSym =
  if resultPos < iter.ast.len:
@@ -159,7 +157,7 @@ proc getClosureIterResult*(g: ModuleGraph; iter: PSym; idgen: IdGenerator): PSym
  else:
    # XXX a bit hacky:
    result = newSym(skResult, getIdent(g.cache, ":result"), idgen, iter, iter.info, {})
-    result.typ = iter.typ.returnType
+    result.typ = iter.typ[0]
    incl(result.flags, sfUsed)
    iter.ast.add newSymNode(result)

@@ -174,23 +172,26 @@ proc addHiddenParam(routine: PSym, param: PSym) =
  assert sfFromGeneric in param.flags
  #echo "produced environment: ", param.id, " for ", routine.id

-proc getEnvParam*(routine: PSym): PSym =
-  if routine.ast.isNil: return nil
+proc getHiddenParam(g: ModuleGraph; routine: PSym): PSym =
  let params = routine.ast[paramsPos]
  let hidden = lastSon(params)
  if hidden.kind == nkSym and hidden.sym.kind == skParam and hidden.sym.name.s == paramName:
    result = hidden.sym
    assert sfFromGeneric in result.flags
  else:
-    result = nil
-
-proc getHiddenParam(g: ModuleGraph; routine: PSym): PSym =
-  result = getEnvParam(routine)
-  if result.isNil:
    # writeStackTrace()
    localError(g.config, routine.info, "internal error: could not find env param for " & routine.name.s)
    result = routine

+proc getEnvParam*(routine: PSym): PSym =
+  let params = routine.ast[paramsPos]
+  let hidden = lastSon(params)
+  if hidden.kind == nkSym and hidden.sym.name.s == paramName:
+    result = hidden.sym
+    assert sfFromGeneric in result.flags
+  else:
+    result = nil
+
 proc interestingVar(s: PSym): bool {.inline.} =
  result = s.kind in {skVar, skLet, skTemp, skForVar, skParam, skResult} and
    sfGlobal notin s.flags and
@@ -199,7 +200,7 @@ proc interestingVar(s: PSym): bool {.inline.} =
 proc illegalCapture(s: PSym): bool {.inline.} =
  result = classifyViewType(s.typ) != noView or s.kind == skResult

-proc isInnerProc*(s: PSym): bool =
+proc isInnerProc(s: PSym): bool =
  if s.kind in {skProc, skFunc, skMethod, skConverter, skIterator} and s.magic == mNone:
    result = s.skipGenericOwner.kind in routineKinds
  else:
@@ -229,14 +230,23 @@ proc makeClosure*(g: ModuleGraph; idgen: IdGenerator; prc: PSym; env: PNode; inf
  if tfHasAsgn in result.typ.flags or optSeqDestructors in g.config.globalOptions:
    prc.flags.incl sfInjectDestructors

-template liftingHarmful(conf: ConfigRef; owner: PSym): bool =
+proc interestingIterVar(s: PSym): bool {.inline.} =
+  # XXX optimization: Only lift the variable if it lives across
+  # yield/return boundaries! This can potentially speed up
+  # closure iterators quite a bit.
+  result = s.kind in {skResult, skVar, skLet, skTemp, skForVar} and sfGlobal notin s.flags
+
+template isIterator*(owner: PSym): bool =
+  owner.kind == skIterator and owner.typ.callConv == ccClosure
+
+proc liftingHarmful(conf: ConfigRef; owner: PSym): bool {.inline.} =
  ## lambda lifting can be harmful for JS-like code generators.
  let isCompileTime = sfCompileTime in owner.flags or owner.kind == skMacro
-  jsNoLambdaLifting in conf.legacyFeatures and conf.backend == backendJs and not isCompileTime
+  result = conf.backend == backendJs and not isCompileTime

 proc createTypeBoundOpsLL(g: ModuleGraph; refType: PType; info: TLineInfo; idgen: IdGenerator; owner: PSym) =
  if owner.kind != skMacro:
-    createTypeBoundOps(g, nil, refType.elementType, info, idgen)
+    createTypeBoundOps(g, nil, refType.lastSon, info, idgen)
    createTypeBoundOps(g, nil, refType, info, idgen)
    if tfHasAsgn in refType.flags or optSeqDestructors in g.config.globalOptions:
      owner.flags.incl sfInjectDestructors
@@ -254,7 +264,8 @@ proc liftIterSym*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PN
  let iter = n.sym
  assert iter.isIterator

-  result = newNodeIT(nkStmtListExpr, n.info, iter.typ)
+  result = newNodeIT(nkStmtListExpr, n.info, n.typ)
+
  let hp = getHiddenParam(g, iter)
  var env: PNode
  if owner.isIterator:
@@ -275,6 +286,15 @@ proc liftIterSym*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PN
  createTypeBoundOpsLL(g, env.typ, n.info, idgen, owner)
  result.add makeClosure(g, idgen, iter, env, n.info)

+proc freshVarForClosureIter*(g: ModuleGraph; s: PSym; idgen: IdGenerator; owner: PSym): PNode =
+  let envParam = getHiddenParam(g, owner)
+  let obj = envParam.typ.skipTypes({tyOwned, tyRef, tyPtr})
+  let field = addField(obj, s, g.cache, idgen)
+
+  var access = newSymNode(envParam)
+  assert obj.kind == tyObject
+  result = rawIndirectAccess(access, field, s.info)
+
 # ------------------ new stuff -------------------------------------------

 proc markAsClosure(g: ModuleGraph; owner: PSym; n: PNode) =
@@ -284,8 +304,8 @@ proc markAsClosure(g: ModuleGraph; owner: PSym; n: PNode) =
    localError(g.config, n.info,
      ("'$1' is of type <$2> which cannot be captured as it would violate memory" &
       " safety, declared here: $3; using '-d:nimNoLentIterators' helps in some cases." &
-       " Consider using a <ref T> which can be captured.") %
-      [s.name.s, typeToString(s.typ.skipTypes({tyVar})), g.config$s.info])
+       " Consider using a <ref $2> which can be captured.") %
+      [s.name.s, typeToString(s.typ), g.config$s.info])
  elif not (owner.typ.isClosure or owner.isNimcall and not owner.isExplicitCallConv or isEnv):
    localError(g.config, n.info, "illegal capture '$1' because '$2' has the calling convention: <$3>" %
      [s.name.s, owner.name.s, $owner.typ.callConv])
@@ -322,13 +342,9 @@ proc getEnvTypeForOwner(c: var DetectionPass; owner: PSym;
                        info: TLineInfo): PType =
  result = c.ownerToType.getOrDefault(owner.id)
  if result.isNil:
-    let env = getEnvParam(owner)
-    if env.isNil or not owner.isIterator:
-      result = newType(tyRef, c.idgen, owner)
-      let obj = createEnvObj(c.graph, c.idgen, owner, info)
-      rawAddSon(result, obj)
-    else:
-      result = env.typ
+    result = newType(tyRef, c.idgen, owner)
+    let obj = createEnvObj(c.graph, c.idgen, owner, info)
+    rawAddSon(result, obj)
    c.ownerToType[owner.id] = result

 proc asOwnedRef(c: var DetectionPass; t: PType): PType =
@@ -420,12 +436,6 @@ proc addClosureParam(c: var DetectionPass; fn: PSym; info: TLineInfo) =
    localError(c.graph.config, fn.info, "internal error: inconsistent environment type")
  #echo "adding closure to ", fn.name.s

-proc iterEnvHasUpField(g: ModuleGraph, iter: PSym): bool =
-  let cp = getEnvParam(iter)
-  doAssert(cp != nil, "Env param not present in iter")
-  let upField = lookupInRecord(cp.typ.skipTypes({tyOwned, tyRef, tyPtr}).n, getIdent(g.cache, upName))
-  upField != nil
-
 proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
  case n.kind
  of nkSym:
@@ -444,12 +454,22 @@ proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
        let body = transformBody(c.graph, c.idgen, s, {useCache})
        detectCapturedVars(body, s, c)
    let ow = s.skipGenericOwner
-    let innerClosure = innerProc and s.typ.callConv == ccClosure and (not s.isIterator or iterEnvHasUpField(c.graph, s))
+    let innerClosure = innerProc and s.typ.callConv == ccClosure and not s.isIterator
    let interested = interestingVar(s)
    if ow == owner:
      if owner.isIterator:
        c.somethingToDo = true
        addClosureParam(c, owner, n.info)
+        if interestingIterVar(s):
+          if not c.capturedVars.contains(s.id):
+            if not c.inTypeOf: c.capturedVars.incl(s.id)
+            let obj = getHiddenParam(c.graph, owner).typ.skipTypes({tyOwned, tyRef, tyPtr})
+            #let obj = c.getEnvTypeForOwner(s.owner).skipTypes({tyOwned, tyRef, tyPtr})
+
+            if s.name.id == getIdent(c.graph.cache, ":state").id:
+              obj.n[0].sym.itemId = ItemId(module: s.itemId.module, item: -s.itemId.item)
+            else:
+              discard addField(obj, s, c.graph.cache, c.idgen)
    # direct or indirect dependency:
    elif innerClosure or interested:
      discard """
@@ -531,8 +551,8 @@ proc accessViaEnvParam(g: ModuleGraph; n: PNode; owner: PSym): PNode =
  let envParam = getHiddenParam(g, owner)
  if not envParam.isNil:
    var access = newSymNode(envParam)
-    var obj = access.typ.elementType
    while true:
+      let obj = access.typ[0]
      assert obj.kind == tyObject
      let field = getFieldFromObj(obj, s)
      if field != nil:
@@ -540,7 +560,6 @@ proc accessViaEnvParam(g: ModuleGraph; n: PNode; owner: PSym): PNode =
      let upField = lookupInRecord(obj.n, getIdent(g.cache, upName))
      if upField == nil: break
      access = rawIndirectAccess(access, upField, n.info)
-      obj = access.typ.baseClass
  localError(g.config, n.info, "internal error: environment misses: " & s.name.s)
  result = n

@@ -552,7 +571,7 @@ proc newEnvVar(cache: IdentCache; owner: PSym; typ: PType; info: TLineInfo; idge
  when false:
    if owner.kind == skIterator and owner.typ.callConv == ccClosure:
      let it = getHiddenParam(owner)
-      addUniqueField(it.typ.elementType, v)
+      addUniqueField(it.typ[0], v)
      result = indirectAccess(newSymNode(it), v, v.info)
    else:
      result = newSymNode(v)
@@ -609,7 +628,7 @@ proc rawClosureCreation(owner: PSym;
      let unowned = c.unownedEnvVars[owner.id]
      assert unowned != nil
      let env2 = copyTree(env)
-      env2.typ() = unowned.typ
+      env2.typ = unowned.typ
      result.add newAsgnStmt(unowned, env2, env.info)
      createTypeBoundOpsLL(d.graph, unowned.typ, env.info, d.idgen, owner)

@@ -649,27 +668,16 @@ proc finishClosureCreation(owner: PSym; d: var DetectionPass; c: LiftingPass;
    res.add newAsgnStmt(unowned, nilLit, info)
    createTypeBoundOpsLL(d.graph, unowned.typ, info, d.idgen, owner)

-proc getUpForIter(g: ModuleGraph; owner, iterOwner: PSym, expectedUpTyp: PType): PNode =
-  var p = getHiddenParam(g, owner)
-  var res = p.newSymNode
-  while res.typ.skipTypes({tyOwned, tyRef, tyPtr}) != expectedUpTyp:
-    let upField = lookupInRecord(p.typ.skipTypes({tyOwned, tyRef, tyPtr}).n, getIdent(g.cache, upName))
-    if upField == nil:
-      return nil
-    p = upField
-    res = rawIndirectAccess(res, upField, p.info)
-  res
-
-proc closureCreationForIter(owner: PSym, iter: PNode;
+proc closureCreationForIter(iter: PNode;
                            d: var DetectionPass; c: var LiftingPass): PNode =
  result = newNodeIT(nkStmtListExpr, iter.info, iter.sym.typ)
-  let iterOwner = iter.sym.skipGenericOwner
-  var v = newSym(skVar, getIdent(d.graph.cache, envName), d.idgen, iterOwner, iter.info)
+  let owner = iter.sym.skipGenericOwner
+  var v = newSym(skVar, getIdent(d.graph.cache, envName), d.idgen, owner, iter.info)
  incl(v.flags, sfShadowed)
  v.typ = asOwnedRef(d, getHiddenParam(d.graph, iter.sym).typ)
  var vnode: PNode
-  if iterOwner.isIterator:
-    let it = getHiddenParam(d.graph, iterOwner)
+  if owner.isIterator:
+    let it = getHiddenParam(d.graph, owner)
    addUniqueField(it.typ.skipTypes({tyOwned, tyRef, tyPtr}), v, d.graph.cache, d.idgen)
    vnode = indirectAccess(newSymNode(it), v, v.info)
  else:
@@ -678,14 +686,12 @@ proc closureCreationForIter(owner: PSym, iter: PNode;
    addVar(vs, vnode)
    result.add(vs)
  result.add genCreateEnv(vnode)
-  createTypeBoundOpsLL(d.graph, vnode.typ, iter.info, d.idgen, iterOwner)
+  createTypeBoundOpsLL(d.graph, vnode.typ, iter.info, d.idgen, owner)

  let upField = lookupInRecord(v.typ.skipTypes({tyOwned, tyRef, tyPtr}).n, getIdent(d.graph.cache, upName))
  if upField != nil:
-    let expectedUpTyp = upField.typ.skipTypes({tyOwned, tyRef, tyPtr})
-    let u = if iterOwner == owner: setupEnvVar(iterOwner, d, c, iter.info)
-            else: getUpForIter(d.graph, owner, iterOwner, expectedUpTyp)
-    if u != nil and u.typ.skipTypes({tyOwned, tyRef, tyPtr}) == expectedUpTyp:
+    let u = setupEnvVar(owner, d, c, iter.info)
+    if u.typ.skipTypes({tyOwned, tyRef, tyPtr}) == upField.typ.skipTypes({tyOwned, tyRef, tyPtr}):
      result.add(newAsgnStmt(rawIndirectAccess(vnode, upField, iter.info),
                 u, iter.info))
    else:
@@ -719,7 +725,7 @@ proc symToClosure(n: PNode; owner: PSym; d: var DetectionPass;
    let available = getHiddenParam(d.graph, owner)
    result = makeClosure(d.graph, d.idgen, s, available.newSymNode, n.info)
  elif s.isIterator:
-    result = closureCreationForIter(owner, n, d, c)
+    result = closureCreationForIter(n, d, c)
  elif s.skipGenericOwner == owner:
    # direct dependency, so use the outer's env variable:
    result = makeClosure(d.graph, d.idgen, s, setupEnvVar(owner, d, c, n.info), n.info)
@@ -766,6 +772,8 @@ proc liftCapturedVars(n: PNode; owner: PSym; d: var DetectionPass;
    elif s.id in d.capturedVars:
      if s.owner != owner:
        result = accessViaEnvParam(d.graph, n, owner)
+      elif owner.isIterator and interestingIterVar(s):
+        result = accessViaEnvParam(d.graph, n, owner)
      else:
        result = accessViaEnvVar(n, owner, d, c)
  of nkEmpty..pred(nkSym), succ(nkSym)..nkNilLit, nkComesFrom,
@@ -786,7 +794,7 @@ proc liftCapturedVars(n: PNode; owner: PSym; d: var DetectionPass;
      let oldInContainer = c.inContainer
      c.inContainer = 0
      let m = newSymNode(n[namePos].sym)
-      m.typ() = n.typ
+      m.typ = n.typ
      result = liftCapturedVars(m, owner, d, c)
      c.inContainer = oldInContainer
  of nkHiddenStdConv:
@@ -874,18 +882,19 @@ proc liftIterToProc*(g: ModuleGraph; fn: PSym; body: PNode; ptrType: PType;

 proc liftLambdas*(g: ModuleGraph; fn: PSym, body: PNode; tooEarly: var bool;
                  idgen: IdGenerator; flags: TransformFlags): PNode =
+  # XXX backend == backendJs does not suffice! The compiletime stuff needs
+  # the transformation even when compiling to JS ...
+
+  # However we can do lifting for the stuff which is *only* compiletime.
  let isCompileTime = sfCompileTime in fn.flags or fn.kind == skMacro

-  if body.kind == nkEmpty or (jsNoLambdaLifting in g.config.legacyFeatures and
+  if body.kind == nkEmpty or (
      g.config.backend == backendJs and not isCompileTime) or
      (fn.skipGenericOwner.kind != skModule and force notin flags):

    # ignore forward declaration:
    result = body
    tooEarly = true
-    if fn.isIterator:
-      var d = initDetectionPass(g, fn, idgen)
-      addClosureParam(d, fn, body.info)
  else:
    var d = initDetectionPass(g, fn, idgen)
    detectCapturedVars(body, fn, d)
@@ -984,15 +993,12 @@ proc liftForLoop*(g: ModuleGraph; body: PNode; idgen: IdGenerator; owner: PSym):
  # gather vars in a tuple:
  var v2 = newNodeI(nkLetSection, body.info)
  var vpart = newNodeI(if body.len == 3: nkIdentDefs else: nkVarTuple, body.info)
-  if body.len == 3 and body[0].kind == nkVarTuple:
-    vpart = body[0] # fixes for (i,j) in walk() # bug #15924
-  else:
-    for i in 0..<body.len-2:
-      if body[i].kind == nkSym:
-        body[i].sym.transitionToLet()
-      vpart.add body[i]
+  for i in 0..<body.len-2:
+    if body[i].kind == nkSym:
+      body[i].sym.transitionToLet()
+    vpart.add body[i]

-    vpart.add newNodeI(nkEmpty, body.info) # no explicit type
+  vpart.add newNodeI(nkEmpty, body.info) # no explicit type
  if not env.isNil:
    call[0] = makeClosure(g, idgen, call[0].sym, env.newSymNode, body.info)
  vpart.add call
--- a/compiler/layeredtable.nim
+++ b/compiler/layeredtable.nim
@@ -1,91 +0,0 @@
-import std/[tables]
-import ast
-
-type
-  LayeredIdTableObj* {.acyclic.} = object
-    ## stack of type binding contexts implemented as a linked list
-    topLayer*: TypeMapping
-      ## the mappings on the current layer
-    nextLayer*: ref LayeredIdTableObj
-      ## the parent type binding context, possibly `nil`
-    previousLen*: int
-      ## total length of the bindings up to the parent layer,
-      ## used to track if new bindings were added
-
-const useRef = not defined(gcDestructors)
-  # implementation detail, only arc/orc doesn't cause issues when
-  # using LayeredIdTable as an object and not a ref
-
-when useRef:
-  type LayeredIdTable* = ref LayeredIdTableObj
-else:
-  type LayeredIdTable* = LayeredIdTableObj
-
-proc initLayeredTypeMap*(pt: sink TypeMapping = initTypeMapping()): LayeredIdTable =
-  result = LayeredIdTable(topLayer: pt, nextLayer: nil)
-
-proc shallowCopy*(pt: LayeredIdTable): LayeredIdTable {.inline.} =
-  ## copies only the type bindings of the current layer, but not any parent layers,
-  ## useful for write-only bindings
-  result = LayeredIdTable(topLayer: pt.topLayer, nextLayer: pt.nextLayer, previousLen: pt.previousLen)
-
-proc currentLen*(pt: LayeredIdTable): int =
-  ## the sum of the cached total binding count of the parents and
-  ## the current binding count, just used to track if bindings were added
-  pt.previousLen + pt.topLayer.len
-
-proc newTypeMapLayer*(pt: LayeredIdTable): LayeredIdTable =
-  result = LayeredIdTable(topLayer: initTable[ItemId, PType](), previousLen: pt.currentLen)
-  when useRef:
-    result.nextLayer = pt
-  else:
-    new(result.nextLayer)
-    result.nextLayer[] = pt
-
-proc setToPreviousLayer*(pt: var LayeredIdTable) {.inline.} =
-  when useRef:
-    pt = pt.nextLayer
-  else:
-    when defined(gcDestructors):
-      pt = pt.nextLayer[]
-    else:
-      # workaround refc
-      let tmp = pt.nextLayer[]
-      pt = tmp
-
-iterator pairs*(pt: LayeredIdTable): (ItemId, PType) =
-  var tm = pt
-  while true:
-    for (k, v) in pairs(tm.topLayer):
-      yield (k, v)
-    if tm.nextLayer == nil:
-      break
-    tm.setToPreviousLayer
-
-proc lookup(typeMap: ref LayeredIdTableObj, key: ItemId): PType =
-  result = nil
-  var tm = typeMap
-  while tm != nil:
-    result = getOrDefault(tm.topLayer, key)
-    if result != nil: return
-    tm = tm.nextLayer
-
-template lookup*(typeMap: ref LayeredIdTableObj, key: PType): PType =
-  ## recursively looks up binding of `key` in all parent layers
-  lookup(typeMap, key.itemId)
-
-when not useRef:
-  proc lookup(typeMap: LayeredIdTableObj, key: ItemId): PType {.inline.} =
-    result = getOrDefault(typeMap.topLayer, key)
-    if result == nil and typeMap.nextLayer != nil:
-      result = lookup(typeMap.nextLayer, key)
-
-  template lookup*(typeMap: LayeredIdTableObj, key: PType): PType =
-    lookup(typeMap, key.itemId)
-
-proc put(typeMap: var LayeredIdTable, key: ItemId, value: PType) {.inline.} =
-  typeMap.topLayer[key] = value
-
-template put*(typeMap: var LayeredIdTable, key, value: PType) =
-  ## binds `key` to `value` only in current layer
-  put(typeMap, key.itemId, value)
--- a/compiler/layouter.nim
+++ b/compiler/layouter.nim
@@ -9,7 +9,7 @@

 ## Layouter for nimpretty.

-import idents, lexer, ast, lineinfos, llstream, options, msgs, strutils, pathutils
+import idents, lexer, lineinfos, llstream, options, msgs, strutils, pathutils

 const
  MinLineLen = 15
@@ -243,28 +243,23 @@ proc renderTokens*(em: var Emitter): string =

  return content

-type
-  FinalCheck = proc (content: string; origAst: PNode): bool {.nimcall.}
-
-proc writeOut*(em: Emitter; content: string; origAst: PNode; check: FinalCheck) =
+proc writeOut*(em: Emitter, content: string)  =
  ## Write to disk
  let outFile = em.config.absOutFile
  if fileExists(outFile) and readFile(outFile.string) == content:
    discard "do nothing, see #9499"
    return
+  var f = llStreamOpen(outFile, fmWrite)
+  if f == nil:
+    rawMessage(em.config, errGenerated, "cannot open file: " & outFile.string)
+    return
+  f.llStreamWrite content
+  llStreamClose(f)

-  if check(content, origAst):
-    var f = llStreamOpen(outFile, fmWrite)
-    if f == nil:
-      rawMessage(em.config, errGenerated, "cannot open file: " & outFile.string)
-      return
-    f.llStreamWrite content
-    llStreamClose(f)
-
-proc closeEmitter*(em: var Emitter; origAst: PNode; check: FinalCheck) =
+proc closeEmitter*(em: var Emitter) =
  ## Renders emitter tokens and write to a file
  let content = renderTokens(em)
-  em.writeOut(content, origAst, check)
+  em.writeOut(content)

 proc wr(em: var Emitter; x: string; lt: LayoutToken) =
  em.tokens.add x
--- a/compiler/lexer.nim
+++ b/compiler/lexer.nim
@@ -300,7 +300,8 @@ proc getNumber(L: var Lexer, result: var Token) =
    # Used to get slightly human friendlier err messages.
    const literalishChars = {'A'..'Z', 'a'..'z', '0'..'9', '_', '.', '\''}
    var msgPos = L.bufpos
-    var t = Token(literal: "")
+    var t: Token
+    t.literal = ""
    L.bufpos = startpos # Use L.bufpos as pos because of matchChars
    matchChars(L, t, literalishChars)
    # We must verify +/- specifically so that we're not past the literal
--- a/compiler/liftdestructors.nim
+++ b/compiler/liftdestructors.nim
@@ -49,17 +49,17 @@ proc at(a, i: PNode, elemType: PType): PNode =
  result = newNodeI(nkBracketExpr, a.info, 2)
  result[0] = a
  result[1] = i
-  result.typ() = elemType
+  result.typ = elemType

 proc destructorOverridden(g: ModuleGraph; t: PType): bool =
  let op = getAttachedOp(g, t, attachedDestructor)
  op != nil and sfOverridden in op.flags

 proc fillBodyTup(c: var TLiftCtx; t: PType; body, x, y: PNode) =
-  for i, a in t.ikids:
+  for i in 0..<t.len:
    let lit = lowerings.newIntLit(c.g, x.info, i)
-    let b = if c.kind == attachedTrace: y else: y.at(lit, a)
-    fillBody(c, a, body, x.at(lit, a), b)
+    let b = if c.kind == attachedTrace: y else: y.at(lit, t[i])
+    fillBody(c, t[i], body, x.at(lit, t[i]), b)

 proc dotField(x: PNode, f: PSym): PNode =
  result = newNodeI(nkDotExpr, x.info, 2)
@@ -68,7 +68,7 @@ proc dotField(x: PNode, f: PSym): PNode =
  else:
    result[0] = x
  result[1] = newSymNode(f, x.info)
-  result.typ() = f.typ
+  result.typ = f.typ

 proc newAsgnStmt(le, ri: PNode): PNode =
  result = newNodeI(nkAsgn, le.info, 2)
@@ -88,10 +88,10 @@ proc defaultOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    body.add newAsgnStmt(x, y)
  elif c.kind == attachedDestructor and c.addMemReset:
    let call = genBuiltin(c, mDefault, "default", x)
-    call.typ() = t
+    call.typ = t
    body.add newAsgnStmt(x, call)
  elif c.kind == attachedWasMoved:
-    body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+    body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)

 proc genAddr(c: var TLiftCtx; x: PNode): PNode =
  if x.kind == nkHiddenDeref:
@@ -105,7 +105,7 @@ proc genWhileLoop(c: var TLiftCtx; i, dest: PNode): PNode =
  result = newNodeI(nkWhileStmt, c.info, 2)
  let cmp = genBuiltin(c, mLtI, "<", i)
  cmp.add genLen(c.g, dest)
-  cmp.typ() = getSysType(c.g, c.info, tyBool)
+  cmp.typ = getSysType(c.g, c.info, tyBool)
  result[0] = cmp
  result[1] = newNodeI(nkStmtList, c.info)

@@ -127,10 +127,10 @@ proc genContainerOf(c: var TLiftCtx; objType: PType, field, x: PSym): PNode =
  dotExpr.add newSymNode(field)

  let offsetOf = genBuiltin(c, mOffsetOf, "offsetof", dotExpr)
-  offsetOf.typ() = intType
+  offsetOf.typ = intType

  let minusExpr = genBuiltin(c, mSubI, "-", castExpr1)
-  minusExpr.typ() = intType
+  minusExpr.typ = intType
  minusExpr.add offsetOf

  let objPtr = makePtrType(objType.owner, objType, c.idgen)
@@ -139,25 +139,25 @@ proc genContainerOf(c: var TLiftCtx; objType: PType, field, x: PSym): PNode =
  result.add minusExpr

 proc destructorCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
-  var destroy = newNodeIT(nkCall, x.info, op.typ.returnType)
+  var destroy = newNodeIT(nkCall, x.info, op.typ[0])
  destroy.add(newSymNode(op))
-  if op.typ.firstParamType.kind != tyVar:
+  if op.typ[1].kind != tyVar:
    destroy.add x
  else:
    destroy.add genAddr(c, x)
  if sfNeverRaises notin op.flags:
    c.canRaise = true
  if c.addMemReset:
-    result = newTree(nkStmtList, destroy, genBuiltin(c, mWasMoved,  "wasMoved", x))
+    result = newTree(nkStmtList, destroy, genBuiltin(c, mWasMoved,  "`=wasMoved`", x))
  else:
    result = destroy

 proc genWasMovedCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
-  result = newNodeIT(nkCall, x.info, op.typ.returnType)
+  result = newNodeIT(nkCall, x.info, op.typ[0])
  result.add(newSymNode(op))
  result.add genAddr(c, x)

-proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool, enforceWasMoved = false) =
+proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool) =
  case n.kind
  of nkSym:
    if c.filterDiscriminator != nil: return
@@ -167,8 +167,6 @@ proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool,
        enforceDefaultOp:
      defaultOp(c, f.typ, body, x.dotField(f), b)
    else:
-      if enforceWasMoved:
-        body.add genBuiltin(c, mWasMoved, "wasMoved", x.dotField(f))
      fillBody(c, f.typ, body, x.dotField(f), b)
  of nkNilLit: discard
  of nkRecCase:
@@ -207,7 +205,7 @@ proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool,
      branch[^1] = newNodeI(nkStmtList, c.info)

      fillBodyObj(c, n[i].lastSon, branch[^1], x, y,
-                  enforceDefaultOp = localEnforceDefaultOp, enforceWasMoved = c.kind == attachedAsgn)
+                  enforceDefaultOp = localEnforceDefaultOp)
      if branch[^1].len == 0: inc emptyBranches
      caseStmt.add(branch)
    if emptyBranches != n.len-1:
@@ -218,29 +216,20 @@ proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool,
      fillBodyObj(c, n[0], body, x, y, enforceDefaultOp = false)
    c.filterDiscriminator = oldfilterDiscriminator
  of nkRecList:
-    for t in items(n): fillBodyObj(c, t, body, x, y, enforceDefaultOp, enforceWasMoved)
+    for t in items(n): fillBodyObj(c, t, body, x, y, enforceDefaultOp)
  else:
    illFormedAstLocal(n, c.g.config)

 proc fillBodyObjTImpl(c: var TLiftCtx; t: PType, body, x, y: PNode) =
-  if t.baseClass != nil:
-    let dest = newNodeIT(nkHiddenSubConv, c.info, t.baseClass)
-    dest.add newNodeI(nkEmpty, c.info)
-    dest.add x
-    var src = y
-    if c.kind in {attachedAsgn, attachedDeepCopy, attachedSink}:
-      src = newNodeIT(nkHiddenSubConv, c.info, t.baseClass)
-      src.add newNodeI(nkEmpty, c.info)
-      src.add y
-
-    fillBody(c, skipTypes(t.baseClass, abstractPtrs), body, dest, src)
+  if t.len > 0 and t[0] != nil:
+    fillBody(c, skipTypes(t[0], abstractPtrs), body, x, y)
  fillBodyObj(c, t.n, body, x, y, enforceDefaultOp = false)

 proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
  var hasCase = isCaseObj(t.n)
  var obj = t
-  while obj.baseClass != nil:
-    obj = skipTypes(obj.baseClass, abstractPtrs)
+  while obj.len > 0 and obj[0] != nil:
+    obj = skipTypes(obj[0], abstractPtrs)
    hasCase = hasCase or isCaseObj(obj.n)

  if hasCase and c.kind in {attachedAsgn, attachedDeepCopy}:
@@ -265,7 +254,7 @@ proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
      # because the wasMoved(dest) call would zero out src, if dest aliases src.
      var cond = newTree(nkCall, newSymNode(c.g.getSysMagic(c.info, "==", mEqRef)),
        newTreeIT(nkAddr, c.info, makePtrType(c.fn, x.typ, c.idgen), x), newTreeIT(nkAddr, c.info, makePtrType(c.fn, y.typ, c.idgen), y))
-      cond.typ() = getSysType(c.g, x.info, tyBool)
+      cond.typ = getSysType(c.g, x.info, tyBool)
      body.add genIf(c, cond, newTreeI(nkReturnStmt, c.info, newNodeI(nkEmpty, c.info)))
    var temp = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), c.idgen, c.fn, c.info)
    temp.typ = x.typ
@@ -277,8 +266,7 @@ proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
    #body.add newAsgnStmt(blob, x)

    var wasMovedCall = newNodeI(nkCall, c.info)
-    wasMovedCall.add(newSymNode(createMagic(c.g, c.idgen, "wasMoved", mWasMoved)))
-
+    wasMovedCall.add(newSymNode(createMagic(c.g, c.idgen, "`=wasMoved`", mWasMoved)))
    wasMovedCall.add x # mWasMoved does not take the address
    body.add wasMovedCall

@@ -291,17 +279,16 @@ proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
    c.kind = attachedDestructor
    fillBodyObjTImpl(c, t, body, blob, y)
    c.kind = prevKind
-
  else:
    fillBodyObjTImpl(c, t, body, x, y)

 proc boolLit*(g: ModuleGraph; info: TLineInfo; value: bool): PNode =
  result = newIntLit(g, info, ord value)
-  result.typ() = getSysType(g, info, tyBool)
+  result.typ = getSysType(g, info, tyBool)

 proc getCycleParam(c: TLiftCtx): PNode =
  assert c.kind in {attachedAsgn, attachedDup}
-  if c.fn.typ.len == 3 + ord(c.kind == attachedAsgn):
+  if c.fn.typ.len == 4:
    result = c.fn.typ.n.lastSon
    assert result.kind == nkSym
    assert result.sym.name.s == "cyclic"
@@ -315,35 +302,27 @@ proc newHookCall(c: var TLiftCtx; op: PSym; x, y: PNode): PNode =
  result.add newSymNode(op)
  if sfNeverRaises notin op.flags:
    c.canRaise = true
-  if op.typ.firstParamType.kind == tyVar:
+  if op.typ[1].kind == tyVar:
    result.add genAddr(c, x)
  else:
    result.add x
  if y != nil:
    result.add y
-  if op.typ.signatureLen == 4:
+  if op.typ.len == 4:
    assert y != nil
-    if c.fn.typ.signatureLen == 4:
+    if c.fn.typ.len == 4:
      result.add getCycleParam(c)
    else:
      # assume the worst: A cycle is created:
      result.add boolLit(c.g, y.info, true)

 proc newOpCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
-  result = newNodeIT(nkCall, x.info, op.typ.returnType)
+  result = newNodeIT(nkCall, x.info, op.typ[0])
  result.add(newSymNode(op))
  result.add x
  if sfNeverRaises notin op.flags:
    c.canRaise = true

-  if c.kind == attachedDup and op.typ.len == 3:
-    assert x != nil
-    if c.fn.typ.len == 3:
-      result.add getCycleParam(c)
-    else:
-      # assume the worst: A cycle is created:
-      result.add boolLit(c.g, x.info, true)
-
 proc newDeepCopyCall(c: var TLiftCtx; op: PSym; x, y: PNode): PNode =
  result = newAsgnStmt(x, newOpCall(c, op, y))

@@ -546,18 +525,18 @@ proc newSeqCall(c: var TLiftCtx; x, y: PNode): PNode =
  # don't call genAddr(c, x) here:
  result = genBuiltin(c, mNewSeq, "newSeq", x)
  let lenCall = genBuiltin(c, mLengthSeq, "len", y)
-  lenCall.typ() = getSysType(c.g, x.info, tyInt)
+  lenCall.typ = getSysType(c.g, x.info, tyInt)
  result.add lenCall

 proc setLenStrCall(c: var TLiftCtx; x, y: PNode): PNode =
  let lenCall = genBuiltin(c, mLengthStr, "len", y)
-  lenCall.typ() = getSysType(c.g, x.info, tyInt)
+  lenCall.typ = getSysType(c.g, x.info, tyInt)
  result = genBuiltin(c, mSetLengthStr, "setLen", x) # genAddr(g, x))
  result.add lenCall

 proc setLenSeqCall(c: var TLiftCtx; t: PType; x, y: PNode): PNode =
  let lenCall = genBuiltin(c, mLengthSeq, "len", y)
-  lenCall.typ() = getSysType(c.g, x.info, tyInt)
+  lenCall.typ = getSysType(c.g, x.info, tyInt)
  var op = getSysMagic(c.g, x.info, "setLen", mSetLengthSeq)
  op = instantiateGeneric(c, op, t, t)
  result = newTree(nkCall, newSymNode(op, x.info), x, lenCall)
@@ -566,7 +545,7 @@ proc forallElements(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  let counterIdx = body.len
  let i = declareCounter(c, body, toInt64(firstOrd(c.g.config, t)))
  let whileLoop = genWhileLoop(c, i, x)
-  let elemType = t.elementType
+  let elemType = t.lastSon
  let b = if c.kind == attachedTrace: y else: y.at(i, elemType)
  fillBody(c, elemType, whileLoop[1], x.at(i, elemType), b)
  if whileLoop[1].len > 0:
@@ -580,7 +559,7 @@ proc checkSelfAssignment(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      newTreeIT(nkAddr, c.info, makePtrType(c.fn, x.typ, c.idgen), x),
      newTreeIT(nkAddr, c.info, makePtrType(c.fn, y.typ, c.idgen), y)
      )
-  cond.typ() = getSysType(c.g, c.info, tyBool)
+  cond.typ = getSysType(c.g, c.info, tyBool)
  body.add genIf(c, cond, newTreeI(nkReturnStmt, c.info, newNodeI(nkEmpty, c.info)))

 proc fillSeqOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
@@ -613,7 +592,7 @@ proc fillSeqOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    if canFormAcycle(c.g, t.elemType):
      # follow all elements:
      forallElements(c, t, body, x, y)
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)

 proc useSeqOrStrOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  createTypeBoundOps(c.g, c.c, t, body.info, c.idgen)
@@ -651,7 +630,7 @@ proc useSeqOrStrOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      if op == nil:
        return # protect from recursion
      body.add newHookCall(c, op, x, y)
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)
  of attachedDup:
    # XXX: replace these with assertions.
    let op = getAttachedOp(c.g, t, c.kind)
@@ -673,11 +652,11 @@ proc fillStrOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    body.add genBuiltin(c, mDestroy, "destroy", x)
  of attachedTrace:
    discard "strings are atomic and have no inner elements that are to trace"
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)

 proc cyclicType*(g: ModuleGraph, t: PType): bool =
  case t.kind
-  of tyRef: result = types.canFormAcycle(g, t.elementType)
+  of tyRef: result = types.canFormAcycle(g, t.lastSon)
  of tyProc: result = t.callConv == ccClosure
  else: result = false

@@ -702,7 +681,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =

  ]#
  var actions = newNodeI(nkStmtList, c.info)
-  let elemType = t.elementType
+  let elemType = t.lastSon

  createTypeBoundOps(c.g, c.c, elemType, c.info, c.idgen)
  let isCyclic = c.g.config.selectedGC == gcOrc and types.canFormAcycle(c.g, elemType)
@@ -721,7 +700,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  if isFinal(elemType):
    addDestructorCall(c, elemType, actions, genDeref(tmp, nkDerefExpr))
    var alignOf = genBuiltin(c, mAlignOf, "alignof", newNodeIT(nkType, c.info, elemType))
-    alignOf.typ() = getSysType(c.g, c.info, tyInt)
+    alignOf.typ = getSysType(c.g, c.info, tyInt)
    actions.add callCodegenProc(c.g, "nimRawDispose", c.info, tmp, alignOf)
  else:
    addDestructorCall(c, elemType, newNodeI(nkStmtList, c.info), genDeref(tmp, nkDerefExpr))
@@ -731,7 +710,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  if isCyclic:
    if isFinal(elemType):
      let typInfo = genBuiltin(c, mGetTypeInfoV2, "getTypeInfoV2", newNodeIT(nkType, x.info, elemType))
-      typInfo.typ() = getSysType(c.g, c.info, tyPointer)
+      typInfo.typ = getSysType(c.g, c.info, tyPointer)
      cond = callCodegenProc(c.g, "nimDecRefIsLastCyclicStatic", c.info, tmp, typInfo)
    else:
      cond = callCodegenProc(c.g, "nimDecRefIsLastCyclicDyn", c.info, tmp)
@@ -739,7 +718,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    cond = callCodegenProc(c.g, "nimDecRefIsLastDyn", c.info, x)
  else:
    cond = callCodegenProc(c.g, "nimDecRefIsLast", c.info, x)
-  cond.typ() = getSysType(c.g, x.info, tyBool)
+  cond.typ = getSysType(c.g, x.info, tyBool)

  case c.kind
  of attachedSink:
@@ -766,13 +745,13 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    if isCyclic:
      if isFinal(elemType):
        let typInfo = genBuiltin(c, mGetTypeInfoV2, "getTypeInfoV2", newNodeIT(nkType, x.info, elemType))
-        typInfo.typ() = getSysType(c.g, c.info, tyPointer)
+        typInfo.typ = getSysType(c.g, c.info, tyPointer)
        body.add callCodegenProc(c.g, "nimTraceRef", c.info, genAddrOf(x, c.idgen), typInfo, y)
      else:
        # If the ref is polymorphic we have to account for this
        body.add callCodegenProc(c.g, "nimTraceRefDyn", c.info, genAddrOf(x, c.idgen), y)
      #echo "can follow ", elemType, " static ", isFinal(elemType)
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)
  of attachedDup:
    if isCyclic:
      body.add newAsgnStmt(x, y)
@@ -787,7 +766,7 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  ## Closures are really like refs except they always use a virtual destructor
  ## and we need to do the refcounting only on the ref field which we call 'xenv':
  let xenv = genBuiltin(c, mAccessEnv, "accessEnv", x)
-  xenv.typ() = getSysType(c.g, c.info, tyPointer)
+  xenv.typ = getSysType(c.g, c.info, tyPointer)

  let isCyclic = c.g.config.selectedGC == gcOrc
  let tmp =
@@ -803,7 +782,7 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    if isCyclic: "nimDecRefIsLastCyclicDyn"
    else: "nimDecRefIsLast"
  let cond = callCodegenProc(c.g, decRefProc, c.info, tmp)
-  cond.typ() = getSysType(c.g, x.info, tyBool)
+  cond.typ = getSysType(c.g, x.info, tyBool)

  case c.kind
  of attachedSink:
@@ -815,7 +794,7 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      body.add newAsgnStmt(x, y)
  of attachedAsgn:
    let yenv = genBuiltin(c, mAccessEnv, "accessEnv", y)
-    yenv.typ() = getSysType(c.g, c.info, tyPointer)
+    yenv.typ = getSysType(c.g, c.info, tyPointer)
    if isCyclic:
      body.add genIf(c, yenv, callCodegenProc(c.g, "nimIncRefCyclic", c.info, yenv, getCycleParam(c)))
      body.add newAsgnStmt(x, y)
@@ -827,7 +806,7 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      body.add newAsgnStmt(x, y)
  of attachedDup:
    let yenv = genBuiltin(c, mAccessEnv, "accessEnv", y)
-    yenv.typ() = getSysType(c.g, c.info, tyPointer)
+    yenv.typ = getSysType(c.g, c.info, tyPointer)
    if isCyclic:
      body.add newAsgnStmt(x, y)
      body.add genIf(c, yenv, callCodegenProc(c.g, "nimIncRefCyclic", c.info, yenv, getCycleParam(c)))
@@ -839,7 +818,7 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  of attachedDeepCopy: assert(false, "cannot happen")
  of attachedTrace:
    body.add callCodegenProc(c.g, "nimTraceRefDyn", c.info, genAddrOf(xenv, c.idgen), y)
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)

 proc weakrefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  case c.kind
@@ -867,19 +846,19 @@ proc weakrefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      body.sons.insert(des, 0)
  of attachedDeepCopy: assert(false, "cannot happen")
  of attachedTrace: discard
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)

 proc ownedRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  var actions = newNodeI(nkStmtList, c.info)

-  let elemType = t.skipModifier
+  let elemType = t.lastSon
  #fillBody(c, elemType, actions, genDeref(x), genDeref(y))
  #var disposeCall = genBuiltin(c, mDispose, "dispose", x)

  if isFinal(elemType):
    addDestructorCall(c, elemType, actions, genDeref(x, nkDerefExpr))
    var alignOf = genBuiltin(c, mAlignOf, "alignof", newNodeIT(nkType, c.info, elemType))
-    alignOf.typ() = getSysType(c.g, c.info, tyInt)
+    alignOf.typ = getSysType(c.g, c.info, tyInt)
    actions.add callCodegenProc(c.g, "nimRawDispose", c.info, x, alignOf)
  else:
    addDestructorCall(c, elemType, newNodeI(nkStmtList, c.info), genDeref(x, nkDerefExpr))
@@ -895,21 +874,21 @@ proc ownedRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    body.add genIf(c, x, actions)
  of attachedDeepCopy: assert(false, "cannot happen")
  of attachedTrace: discard
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)

 proc closureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  if c.kind == attachedDeepCopy:
    # a big problem is that we don't know the environment's type here, so we
    # have to go through some indirection; we delegate this to the codegen:
    let call = newNodeI(nkCall, c.info, 2)
-    call.typ() = t
+    call.typ = t
    call[0] = newSymNode(createMagic(c.g, c.idgen, "deepCopy", mDeepCopy))
    call[1] = y
    body.add newAsgnStmt(x, call)
  elif (optOwnedRefs in c.g.config.globalOptions and
      optRefCheck in c.g.config.options) or c.g.config.selectedGC in {gcArc, gcAtomicArc, gcOrc}:
    let xx = genBuiltin(c, mAccessEnv, "accessEnv", x)
-    xx.typ() = getSysType(c.g, c.info, tyPointer)
+    xx.typ = getSysType(c.g, c.info, tyPointer)
    case c.kind
    of attachedSink:
      # we 'nil' y out afterwards so we *need* to take over its reference
@@ -918,13 +897,13 @@ proc closureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      body.add newAsgnStmt(x, y)
    of attachedAsgn:
      let yy = genBuiltin(c, mAccessEnv, "accessEnv", y)
-      yy.typ() = getSysType(c.g, c.info, tyPointer)
+      yy.typ = getSysType(c.g, c.info, tyPointer)
      body.add genIf(c, yy, callCodegenProc(c.g, "nimIncRef", c.info, yy))
      body.add genIf(c, xx, callCodegenProc(c.g, "nimDecWeakRef", c.info, xx))
      body.add newAsgnStmt(x, y)
    of attachedDup:
      let yy = genBuiltin(c, mAccessEnv, "accessEnv", y)
-      yy.typ() = getSysType(c.g, c.info, tyPointer)
+      yy.typ = getSysType(c.g, c.info, tyPointer)
      body.add newAsgnStmt(x, y)
      body.add genIf(c, yy, callCodegenProc(c.g, "nimIncRef", c.info, yy))
    of attachedDestructor:
@@ -935,11 +914,11 @@ proc closureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
        body.sons.insert(des, 0)
    of attachedDeepCopy: assert(false, "cannot happen")
    of attachedTrace: discard
-    of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+    of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)

 proc ownedClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  let xx = genBuiltin(c, mAccessEnv, "accessEnv", x)
-  xx.typ() = getSysType(c.g, c.info, tyPointer)
+  xx.typ = getSysType(c.g, c.info, tyPointer)
  var actions = newNodeI(nkStmtList, c.info)
  #discard addDestructorCall(c, elemType, newNodeI(nkStmtList, c.info), genDeref(xx))
  actions.add callCodegenProc(c.g, "nimDestroyAndDispose", c.info, xx)
@@ -953,7 +932,7 @@ proc ownedClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    body.add genIf(c, xx, actions)
  of attachedDeepCopy: assert(false, "cannot happen")
  of attachedTrace: discard
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)

 proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  case t.kind
@@ -1003,13 +982,9 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      # 'selectedGC' here to determine if we have the new runtime.
      discard considerUserDefinedOp(c, t, body, x, y)
    elif tfHasAsgn in t.flags:
-      # seqs with elements using custom hooks in refc
      if c.kind in {attachedAsgn, attachedSink, attachedDeepCopy}:
        body.add newSeqCall(c, x, y)
-      if c.kind == attachedWasMoved:
-        body.add genBuiltin(c, mWasMoved, "wasMoved", x)
-      else:
-        forallElements(c, t, body, x, y)
+      forallElements(c, t, body, x, y)
    else:
      defaultOp(c, t, body, x, y)
  of tyString:
@@ -1026,7 +1001,7 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
        of {attachedAsgn, attachedSink, attachedDup}:
          body.add newAsgnStmt(x, y)
        of attachedWasMoved:
-          body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+          body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)
        else:
          fillBodyObjT(c, t, body, x, y)
      else:
@@ -1042,7 +1017,7 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
          fillBodyObjT(c, t, body, x, y)
  of tyDistinct:
    if not considerUserDefinedOp(c, t, body, x, y):
-      fillBody(c, t.elementType, body, x, y)
+      fillBody(c, t[0], body, x, y)
  of tyTuple:
    fillBodyTup(c, t, body, x, y)
  of tyVarargs, tyOpenArray:
@@ -1051,7 +1026,7 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    else:
      discard "cannot copy openArray"

-  of tyFromExpr, tyError, tyBuiltInTypeClass, tyUserTypeClass,
+  of tyFromExpr, tyProxy, tyBuiltInTypeClass, tyUserTypeClass,
     tyUserTypeClassInst, tyCompositeTypeClass, tyAnd, tyOr, tyNot, tyAnything,
     tyGenericParam, tyGenericBody, tyNil, tyUntyped, tyTyped,
     tyTypeDesc, tyGenericInvocation, tyForward, tyStatic:
@@ -1059,14 +1034,14 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    discard
  of tyOrdinal, tyRange, tyInferred,
     tyGenericInst, tyAlias, tySink:
-    fillBody(c, skipModifier(t), body, x, y)
+    fillBody(c, lastSon(t), body, x, y)
  of tyConcept, tyIterable: raiseAssert "unreachable"

 proc produceSymDistinctType(g: ModuleGraph; c: PContext; typ: PType;
                            kind: TTypeAttachedOp; info: TLineInfo;
                            idgen: IdGenerator): PSym =
  assert typ.kind == tyDistinct
-  let baseType = typ.elementType
+  let baseType = typ[0]
  if getAttachedOp(g, baseType, kind) == nil:
    discard produceSym(g, c, baseType, kind, info, idgen)
  result = getAttachedOp(g, baseType, kind)
@@ -1118,7 +1093,7 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
                   idgen, result, info)

  if kind == attachedDestructor and g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc} and
-     ((g.config.isDefined("nimPreviewNonVarDestructor") and not isDiscriminant) or (typ.kind in {tyRef, tyString, tySequence})):
+     ((g.config.isDefined("nimPreviewNonVarDestructor") and not isDiscriminant) or typ.kind in {tyRef, tyString, tySequence}):
    dest.typ = typ
  else:
    dest.typ = makeVarType(typ.owner, typ, idgen)
@@ -1155,8 +1130,8 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
 proc genTypeFieldCopy(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  let xx = genBuiltin(c, mAccessTypeField, "accessTypeField", x)
  let yy = genBuiltin(c, mAccessTypeField, "accessTypeField", y)
-  xx.typ() = getSysType(c.g, c.info, tyPointer)
-  yy.typ() = xx.typ
+  xx.typ = getSysType(c.g, c.info, tyPointer)
+  yy.typ = xx.typ
  body.add newAsgnStmt(xx, yy)

 proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
@@ -1172,7 +1147,7 @@ proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
                   fn: result)

  let dest = if kind == attachedDup: result.ast[resultPos].sym else: result.typ.n[1].sym
-  let d = if result.typ.firstParamType.kind == tyVar: newDeref(newSymNode(dest)) else: newSymNode(dest)
+  let d = if result.typ[1].kind == tyVar: newDeref(newSymNode(dest)) else: newSymNode(dest)
  let src = case kind
            of {attachedDestructor, attachedWasMoved}: newNodeIT(nkSym, info, getSysType(g, info, tyPointer))
            of attachedDup: newSymNode(result.typ.n[1].sym)
@@ -1185,7 +1160,7 @@ proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
    ## compiler can use a combination of `=destroy` and memCopy for sink op
    dest.flags.incl sfCursor
    let op = getAttachedOp(g, typ, attachedDestructor)
-    result.ast[bodyPos].add newOpCall(a, op, if op.typ.firstParamType.kind == tyVar: d[0] else: d)
+    result.ast[bodyPos].add newOpCall(a, op, if op.typ[1].kind == tyVar: d[0] else: d)
    result.ast[bodyPos].add newAsgnStmt(d, src)
  else:
    var tk: TTypeKind
@@ -1200,18 +1175,11 @@ proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
      fillStrOp(a, typ, result.ast[bodyPos], d, src)
    else:
      fillBody(a, typ, result.ast[bodyPos], d, src)
-      if tk == tyObject and a.kind in {attachedAsgn, attachedSink, attachedDeepCopy, attachedDup} and not isObjLackingTypeField(typ):
+      if tk == tyObject and a.kind in {attachedAsgn, attachedSink, attachedDeepCopy, attachedDup} and not lacksMTypeField(typ):
        # bug #19205: Do not forget to also copy the hidden type field:
        genTypeFieldCopy(a, typ, result.ast[bodyPos], d, src)

-  if not a.canRaise:
-    incl result.flags, sfNeverRaises
-    result.ast[pragmasPos] = newNodeI(nkPragma, info)
-    result.ast[pragmasPos].add newTree(nkExprColonExpr,
-        newIdentNode(g.cache.getIdent("raises"),  info), newNodeI(nkBracket, info))
-
-  if kind == attachedDestructor:
-    incl result.options, optQuirky
+  if not a.canRaise: incl result.flags, sfNeverRaises
  completePartialOp(g, idgen.module, typ, kind, result)


@@ -1271,7 +1239,7 @@ proc inst(g: ModuleGraph; c: PContext; t: PType; kind: TTypeAttachedOp; idgen: I
    else:
      localError(g.config, info, "unresolved generic parameter")

-proc isTrival*(s: PSym): bool {.inline.} =
+proc isTrival(s: PSym): bool {.inline.} =
  s == nil or (s.ast != nil and s.ast[bodyPos].len == 0)

 proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInfo;
@@ -1281,10 +1249,6 @@ proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInf
  ## The later 'injectdestructors' pass depends on it.
  if orig == nil or {tfCheckedForDestructor, tfHasMeta} * orig.flags != {}: return
  incl orig.flags, tfCheckedForDestructor
-  # for user defined generic destructors:
-  let origRoot = genericRoot(orig)
-  if origRoot != nil:
-    incl origRoot.flags, tfGenericHasDestructor

  let skipped = orig.skipTypes({tyGenericInst, tyAlias, tySink})
  if isEmptyContainer(skipped) or skipped.kind == tyStatic: return
--- a/compiler/liftlocals.nim
+++ b/compiler/liftlocals.nim
@@ -32,12 +32,12 @@ proc interestingVar(s: PSym): bool {.inline.} =
 proc lookupOrAdd(c: var Ctx; s: PSym; info: TLineInfo): PNode =
  let field = addUniqueField(c.objType, s, c.cache, c.idgen)
  var deref = newNodeI(nkHiddenDeref, info)
-  deref.typ() = c.objType
+  deref.typ = c.objType
  deref.add(newSymNode(c.partialParam, info))
  result = newNodeI(nkDotExpr, info)
  result.add(deref)
  result.add(newSymNode(field))
-  result.typ() = field.typ
+  result.typ = field.typ

 proc liftLocals(n: PNode; i: int; c: var Ctx) =
  let it = n[i]
--- a/compiler/lineinfos.nim
+++ b/compiler/lineinfos.nim
@@ -92,11 +92,8 @@ type
    warnStmtListLambda = "StmtListLambda",
    warnBareExcept = "BareExcept",
    warnImplicitDefaultValue = "ImplicitDefaultValue",
-    warnIgnoredSymbolInjection = "IgnoredSymbolInjection",
    warnStdPrefix = "StdPrefix"
-    warnUnknownNotes = "UnknownNotes"
    warnUser = "User",
-    warnGlobalVarConstructorTemporary = "GlobalVarConstructorTemporary",
    # hints
    hintSuccess = "Success", hintSuccessX = "SuccessX",
    hintCC = "CC",
@@ -110,9 +107,9 @@ type
    hintSource = "Source", hintPerformance = "Performance", hintStackTrace = "StackTrace",
    hintGCStats = "GCStats", hintGlobalVar = "GlobalVar", hintExpandMacro = "ExpandMacro",
    hintUser = "User", hintUserRaw = "UserRaw", hintExtendedContext = "ExtendedContext",
-    hintUnknownRaises = "UnknownRaises",
    hintMsgOrigin = "MsgOrigin", # since 1.3.5
    hintDeclaredLoc = "DeclaredLoc", # since 1.5.1
+    hintUnknownHint = "UnknownHint"

 const
  MsgKindToStr*: array[TMsgKind, string] = [
@@ -199,11 +196,8 @@ const
    warnStmtListLambda: "statement list expression assumed to be anonymous proc; this is deprecated, use `do (): ...` or `proc () = ...` instead",
    warnBareExcept: "$1",
    warnImplicitDefaultValue: "$1",
-    warnIgnoredSymbolInjection: "$1",
    warnStdPrefix: "$1 needs the 'std' prefix",
-    warnUnknownNotes: "$1",
    warnUser: "$1",
-    warnGlobalVarConstructorTemporary: "global variable '$1' initialization requires a temporary variable",
    hintSuccess: "operation successful: $#",
    # keep in sync with `testament.isSuccess`
    hintSuccessX: "$build\n$loc lines; ${sec}s; $mem; proj: $project; out: $output",
@@ -237,9 +231,9 @@ const
    hintUser: "$1",
    hintUserRaw: "$1",
    hintExtendedContext: "$1",
-    hintUnknownRaises: "$1 is a forward declaration without explicit .raises, assuming it can raise anything",
    hintMsgOrigin: "$1",
-    hintDeclaredLoc: "$1"
+    hintDeclaredLoc: "$1",
+    hintUnknownHint: "unknown hint: $1"
  ]

 const
@@ -270,7 +264,6 @@ const
  NotesVerbosity* = computeNotesVerbosity()
  errXMustBeCompileTime* = "'$1' can only be used in compile-time context"
  errArgsNeedRunOption* = "arguments can only be given if the '--run' option is selected"
-  errFloatToString* = "cannot convert '$1' to '$2'"

 type
  TFileInfo* = object
--- a/compiler/linter.nim
+++ b/compiler/linter.nim
@@ -12,7 +12,7 @@
 import std/strutils
 from std/sugar import dup

-import options, ast, msgs, idents, lineinfos, wordrecg, astmsgs, semdata, packages, modulegraphs
+import options, ast, msgs, idents, lineinfos, wordrecg, astmsgs, semdata, packages
 export packages

 const
@@ -97,7 +97,7 @@ template styleCheckDef*(ctx: PContext; info: TLineInfo; sym: PSym; k: TSymKind)
  if optStyleCheck in ctx.config.options and # ignore if styleChecks are off
     {optStyleHint, optStyleError} * ctx.config.globalOptions != {} and # check only if hint/error is enabled
     hintName in ctx.config.notes and # ignore if name checks are not requested
-     ctx.config.belongsToProjectPackageMaybeNil(getModule(ctx.graph, info.fileIndex)) and # ignore foreign packages
+     ctx.config.belongsToProjectPackage(sym) and # ignore foreign packages
     optStyleUsages notin ctx.config.globalOptions and # ignore if requested to only check name usage
     sym.kind != skResult and # ignore `result`
     sym.kind != skTemp and # ignore temporary variables created by the compiler
@@ -138,7 +138,7 @@ template styleCheckUse*(ctx: PContext; info: TLineInfo; sym: PSym) =
  ## Check symbol uses match their definition's style.
  if {optStyleHint, optStyleError} * ctx.config.globalOptions != {} and # ignore if styleChecks are off
     hintName in ctx.config.notes and # ignore if name checks are not requested
-     ctx.config.belongsToProjectPackageMaybeNil(getModule(ctx.graph, info.fileIndex)) and # ignore foreign packages
+     ctx.config.belongsToProjectPackage(sym) and # ignore foreign packages
     sym.kind != skTemp and # ignore temporary variables created by the compiler
     sym.name.s[0] in Letters and # ignore operators TODO: what about unicode symbols???
     sfAnon notin sym.flags: # ignore temporary variables created by the compiler
@@ -154,5 +154,5 @@ template checkPragmaUse*(ctx: PContext; info: TLineInfo; w: TSpecialWord; pragma
  ## Note: This only applies to builtin pragmas, not user pragmas.
  if {optStyleHint, optStyleError} * ctx.config.globalOptions != {} and # ignore if styleChecks are off
     hintName in ctx.config.notes and # ignore if name checks are not requested
-     ctx.config.belongsToProjectPackageMaybeNil(getModule(ctx.graph, info.fileIndex)): # ignore foreign packages
+     (sym != nil and ctx.config.belongsToProjectPackage(sym)): # ignore foreign packages
    checkPragmaUseImpl(ctx.config, info, w, pragmaName)
--- a/compiler/llstream.nim
+++ b/compiler/llstream.nim
@@ -11,7 +11,7 @@

 import
  pathutils
-import std/strutils
+
 when defined(nimPreviewSlimSystem):
  import std/syncio

@@ -68,7 +68,6 @@ when not declared(readLineFromStdin):
  # fallback implementation:
  proc readLineFromStdin(prompt: string, line: var string): bool =
    stdout.write(prompt)
-    stdout.flushFile()
    result = readLine(stdin, line)
    if not result:
      stdout.write("\n")
@@ -86,47 +85,6 @@ const
  LineContinuationOprs = {'+', '-', '*', '/', '\\', '<', '>', '!', '?', '^',
                          '|', '%', '&', '$', '@', '~', ','}
  AdditionalLineContinuationOprs = {'#', ':', '='}
-  LineContinuationTokens = [
-    "let", "var", "const", "type",  # section
-    "object", "tuple",
-    # from ./layouter.oprSet
-    "div", "mod", "shl", "shr", "in", "notin", "is",
-    "isnot", "not", "of", "as", "from", "..", "and", "or", "xor", 
-  ]  # must be all `nimIdentNormalized`-ed
-
-proc eqIdent(a, bNormalized: string): bool =
-  a.nimIdentNormalize == bNormalized
-
-proc endsWithIdent(s, subs: string): bool =
-  let le = subs.len
-  if le > s.len: return false
-  s[^le .. ^1].eqIdent subs
-
-proc continuesWithIdent(s, subs: string, start: int): bool =
-  s.substr(start, start+subs.high).eqIdent subs
-
-proc endsWithIdent(s, subs: string, endIdx: var int): bool =
-  endIdx.dec subs.len
-  result = s.continuesWithIdent(subs, endIdx+1)
-
-proc containsObjectOf(x: string): bool =
-  const sep = ' '
-  var idx = x.rfind(sep)
-  if idx == -1: return
-  template eatWord(word) =  
-    while x[idx] == sep: idx.dec
-    result = x.endsWithIdent(word, idx)
-    if not result: return
-  eatWord "of"
-  eatWord "object"
-  result = true
-
-proc endsWithLineContinuationToken(x: string): bool =
-  result = false
-  for tok in LineContinuationTokens:
-    if x.endsWithIdent(tok):
-      return true
-  result = x.containsObjectOf

 proc endsWithOpr*(x: string): bool =
  result = x.endsWith(LineContinuationOprs)
@@ -134,9 +92,7 @@ proc endsWithOpr*(x: string): bool =
 proc continueLine(line: string, inTripleString: bool): bool {.inline.} =
  result = inTripleString or line.len > 0 and (
        line[0] == ' ' or
-        line.endsWith(LineContinuationOprs+AdditionalLineContinuationOprs) or
-        line.endsWithLineContinuationToken()
-      )
+        line.endsWith(LineContinuationOprs+AdditionalLineContinuationOprs))

 proc countTriples(s: string): int =
  result = 0
@@ -152,10 +108,7 @@ proc llReadFromStdin(s: PLLStream, buf: pointer, bufLen: int): int =
  s.rd = 0
  var line = newStringOfCap(120)
  var triples = 0
-  while true:
-    if not readLineFromStdin(if s.s.len == 0: ">>> " else: "... ", line):
-      # now readLineFromStdin meets EOF (ctrl-D/Z) or ctrl-C
-      quit()
+  while readLineFromStdin(if s.s.len == 0: ">>> " else: "... ", line):
    s.s.add(line)
    s.s.add("\n")
    inc triples, countTriples(line)
--- a/compiler/lookups.nim
+++ b/compiler/lookups.nim
@@ -50,7 +50,7 @@ proc considerQuotedIdent*(c: PContext; n: PNode, origin: PNode = nil): PIdent =
        case x.kind
        of nkIdent: id.add(x.ident.s)
        of nkSym: id.add(x.sym.name.s)
-        of nkSymChoices, nkOpenSym:
+        of nkSymChoices:
          if x[0].kind == nkSym:
            id.add(x[0].sym.name.s)
          else:
@@ -58,7 +58,7 @@ proc considerQuotedIdent*(c: PContext; n: PNode, origin: PNode = nil): PIdent =
        of nkLiterals - nkFloatLiterals: id.add(x.renderTree)
        else: handleError(n, origin)
      result = getIdent(c.cache, id)
-  of nkOpenSymChoice, nkClosedSymChoice, nkOpenSym:
+  of nkOpenSymChoice, nkClosedSymChoice:
    if n[0].kind == nkSym:
      result = n[0].sym.name
    else:
@@ -137,7 +137,7 @@ proc nextIdentIter(ti: var ModuleIter; marked: var IntSet; im: ImportedModule;
        return result

 iterator symbols(im: ImportedModule; marked: var IntSet; name: PIdent; g: ModuleGraph): PSym =
-  var ti: ModuleIter = default(ModuleIter)
+  var ti: ModuleIter
  var candidate = initIdentIter(ti, marked, im, name, g)
  while candidate != nil:
    yield candidate
@@ -150,7 +150,7 @@ iterator importedItems*(c: PContext; name: PIdent): PSym =
      yield s

 proc allPureEnumFields(c: PContext; name: PIdent): seq[PSym] =
-  var ti: TIdentIter = default(TIdentIter)
+  var ti: TIdentIter
  result = @[]
  var res = initIdentIter(ti, c.pureEnumFields, name)
  while res != nil:
@@ -219,33 +219,28 @@ proc debugScopes*(c: PContext; limit=0, max = int.high) {.deprecated.} =
    if i == limit: return
    inc i

-proc searchImportsAll*(c: PContext, s: PIdent, filter: TSymKinds, holding: var seq[PSym]) =
-  var marked = initIntSet()
-  for im in c.imports.mitems:
-    for s in symbols(im, marked, s, c.graph):
-      if s.kind in filter:
-        holding.add s
-
-proc searchScopes*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSym] =
+proc searchInScopesAllCandidatesFilterBy*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSym] =
  result = @[]
  for scope in allScopes(c.currentScope):
-    var ti: TIdentIter = default(TIdentIter)
+    var ti: TIdentIter
    var candidate = initIdentIter(ti, scope.symbols, s)
    while candidate != nil:
      if candidate.kind in filter:
        result.add candidate
      candidate = nextIdentIter(ti, scope.symbols)

-proc searchScopesAll*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSym] =
-  result = searchScopes(c,s,filter)
  if result.len == 0:
-    searchImportsAll(c, s, filter, result)
+    var marked = initIntSet()
+    for im in c.imports.mitems:
+      for s in symbols(im, marked, s, c.graph):
+        if s.kind in filter:
+          result.add s

-proc selectFromScopesElseAll*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSym] =
+proc searchInScopesFilterBy*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSym] =
  result = @[]
  block outer:
    for scope in allScopes(c.currentScope):
-      var ti: TIdentIter = default(TIdentIter)
+      var ti: TIdentIter
      var candidate = initIdentIter(ti, scope.symbols, s)
      while candidate != nil:
        if candidate.kind in filter:
@@ -255,25 +250,17 @@ proc selectFromScopesElseAll*(c: PContext, s: PIdent, filter: TSymKinds): seq[PS
        candidate = nextIdentIter(ti, scope.symbols)

  if result.len == 0:
-    searchImportsAll(c, s, filter, result)
-
-proc cmpScopes*(ctx: PContext, s: PSym): int =
-  # Do not return a negative number
-  if s.originatingModule == ctx.module:
-    result = 2
-    var owner = s
-    while true:
-      owner = owner.skipGenericOwner
-      if owner.kind == skModule: break
-      inc result
-  else:
-    result = 1
+    var marked = initIntSet()
+    for im in c.imports.mitems:
+      for s in symbols(im, marked, s, c.graph):
+        if s.kind in filter:
+          result.add s

 proc isAmbiguous*(c: PContext, s: PIdent, filter: TSymKinds, sym: var PSym): bool =
  result = false
  block outer:
    for scope in allScopes(c.currentScope):
-      var ti: TIdentIter = default(TIdentIter)
+      var ti: TIdentIter
      var candidate = initIdentIter(ti, scope.symbols, s)
      var scopeHasCandidate = false
      while candidate != nil:
@@ -304,16 +291,8 @@ proc isAmbiguous*(c: PContext, s: PIdent, filter: TSymKinds, sym: var PSym): boo
    # imports had a candidate but wasn't ambiguous
    return false

-proc errorSym*(c: PContext, ident: PIdent, info: TLineInfo): PSym =
-  ## creates an error symbol to avoid cascading errors (for IDE support)
-  result = newSym(skError, ident, c.idgen, getCurrOwner(c), info, {})
-  result.typ = errorType(c)
-  incl(result.flags, sfDiscardable)
-  # pretend it's from the top level scope to prevent cascading errors:
-  if c.config.cmd != cmdInteractive and c.compilesContextId == 0:
-    c.moduleScope.addSym(result)
-
 proc errorSym*(c: PContext, n: PNode): PSym =
+  ## creates an error symbol to avoid cascading errors (for IDE support)
  var m = n
  # ensure that 'considerQuotedIdent' can't fail:
  if m.kind == nkDotExpr: m = m[1]
@@ -321,7 +300,12 @@ proc errorSym*(c: PContext, n: PNode): PSym =
      considerQuotedIdent(c, m)
    else:
      getIdent(c.cache, "err:" & renderTree(m))
-  result = errorSym(c, ident, n.info)
+  result = newSym(skError, ident, c.idgen, getCurrOwner(c), n.info, {})
+  result.typ = errorType(c)
+  incl(result.flags, sfDiscardable)
+  # pretend it's from the top level scope to prevent cascading errors:
+  if c.config.cmd != cmdInteractive and c.compilesContextId == 0:
+    c.moduleScope.addSym(result)

 type
  TOverloadIterMode* = enum
@@ -348,7 +332,7 @@ proc getSymRepr*(conf: ConfigRef; s: PSym, getDeclarationPath = true): string =

 proc ensureNoMissingOrUnusedSymbols(c: PContext; scope: PScope) =
  # check if all symbols have been used and defined:
-  var it: TTabIter = default(TTabIter)
+  var it: TTabIter
  var s = initTabIter(it, scope.symbols)
  var missingImpls = 0
  var unusedSyms: seq[tuple[sym: PSym, key: string]] = @[]
@@ -503,7 +487,7 @@ proc mustFixSpelling(c: PContext): bool {.inline.} =
  result = c.config.spellSuggestMax != 0 and c.compilesContextId == 0
    # don't slowdown inside compiles()

-proc fixSpelling(c: PContext, ident: PIdent, result: var string) =
+proc fixSpelling(c: PContext, n: PNode, ident: PIdent, result: var string) =
  ## when we cannot find the identifier, suggest nearby spellings
  var list = initHeapQueue[SpellCandidate]()
  let name0 = ident.s.nimIdentNormalize
@@ -559,47 +543,33 @@ proc errorUseQualifier(c: PContext; info: TLineInfo; s: PSym; amb: var bool): PS
    amb = false

 proc errorUseQualifier*(c: PContext; info: TLineInfo; s: PSym) =
-  var amb: bool = false
+  var amb: bool
  discard errorUseQualifier(c, info, s, amb)

-proc ambiguousIdentifierMsg*(candidates: seq[PSym], prefix = "use one of", indent = 0): string =
-  result = ""
-  for i in 0 ..< indent:
-    result.add(' ')
-  result.add "ambiguous identifier: '" & candidates[0].name.s & "'"
+proc errorUseQualifier(c: PContext; info: TLineInfo; candidates: seq[PSym]; prefix = "use one of") =
+  var err = "ambiguous identifier: '" & candidates[0].name.s & "'"
  var i = 0
  for candidate in candidates:
-    if i == 0: result.add " -- $1 the following:\n" % prefix
-    else: result.add "\n"
-    for i in 0 ..< indent:
-      result.add(' ')
-    result.add "  " & candidate.owner.name.s & "." & candidate.name.s
-    result.add ": " & typeToString(candidate.typ)
+    if i == 0: err.add " -- $1 the following:\n" % prefix
+    else: err.add "\n"
+    err.add "  " & candidate.owner.name.s & "." & candidate.name.s
+    err.add ": " & typeToString(candidate.typ)
    inc i
+  localError(c.config, info, errGenerated, err)

-proc errorUseQualifier*(c: PContext; info: TLineInfo; candidates: seq[PSym]) =
-  localError(c.config, info, errGenerated, ambiguousIdentifierMsg(candidates))
-
-proc ambiguousIdentifierMsg*(choices: PNode, indent = 0): string =
+proc errorUseQualifier*(c: PContext; info:TLineInfo; choices: PNode) =
  var candidates = newSeq[PSym](choices.len)
  let prefix = if choices[0].typ.kind != tyProc: "use one of" else: "you need a helper proc to disambiguate"
  for i, n in choices:
    candidates[i] = n.sym
-  result = ambiguousIdentifierMsg(candidates, prefix, indent)
-
-proc errorUseQualifier*(c: PContext; info:TLineInfo; choices: PNode) =
-  localError(c.config, info, errGenerated, ambiguousIdentifierMsg(choices))
+  errorUseQualifier(c, info, candidates, prefix)

 proc errorUndeclaredIdentifier*(c: PContext; info: TLineInfo; name: string, extra = "") =
  var err: string
  if name == "_":
    err = "the special identifier '_' is ignored in declarations and cannot be used"
  else:
-    err = "undeclared identifier: '" & name & "'"
-    if "`gensym" in name:
-      err.add "; if declared in a template, this identifier may be inconsistently marked inject or gensym"
-    if extra.len != 0:
-      err.add extra
+    err = "undeclared identifier: '" & name & "'" & extra
    if c.recursiveDep.len > 0:
      err.add "\nThis might be caused by a recursive module dependency:\n"
      err.add c.recursiveDep
@@ -607,11 +577,11 @@ proc errorUndeclaredIdentifier*(c: PContext; info: TLineInfo; name: string, extr
      c.recursiveDep = ""
  localError(c.config, info, errGenerated, err)

-proc errorUndeclaredIdentifierHint*(c: PContext; ident: PIdent; info: TLineInfo): PSym =
+proc errorUndeclaredIdentifierHint*(c: PContext; n: PNode, ident: PIdent): PSym =
  var extra = ""
-  if c.mustFixSpelling: fixSpelling(c, ident, extra)
-  errorUndeclaredIdentifier(c, info, ident.s, extra)
-  result = errorSym(c, ident, info)
+  if c.mustFixSpelling: fixSpelling(c, n, ident, extra)
+  errorUndeclaredIdentifier(c, n.info, ident.s, extra)
+  result = errorSym(c, n)

 proc lookUp*(c: PContext, n: PNode): PSym =
  # Looks up a symbol. Generates an error in case of nil.
@@ -619,13 +589,13 @@ proc lookUp*(c: PContext, n: PNode): PSym =
  case n.kind
  of nkIdent:
    result = searchInScopes(c, n.ident, amb)
-    if result == nil: result = errorUndeclaredIdentifierHint(c, n.ident, n.info)
+    if result == nil: result = errorUndeclaredIdentifierHint(c, n, n.ident)
  of nkSym:
    result = n.sym
  of nkAccQuoted:
    var ident = considerQuotedIdent(c, n)
    result = searchInScopes(c, ident, amb)
-    if result == nil: result = errorUndeclaredIdentifierHint(c, ident, n.info)
+    if result == nil: result = errorUndeclaredIdentifierHint(c, n, ident)
  else:
    internalError(c.config, n.info, "lookUp")
    return nil
@@ -639,30 +609,16 @@ type
  TLookupFlag* = enum
    checkAmbiguity, checkUndeclared, checkModule, checkPureEnumFields

-const allExceptModule = {low(TSymKind)..high(TSymKind)} - {skModule, skPackage}
-
-proc lookUpCandidates*(c: PContext, ident: PIdent, filter: set[TSymKind],
-                       includePureEnum = false): seq[PSym] =
-  result = selectFromScopesElseAll(c, ident, filter)
-  if skEnumField in filter and (result.len == 0 or includePureEnum):
-    result.add allPureEnumFields(c, ident)
-
 proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
+  const allExceptModule = {low(TSymKind)..high(TSymKind)} - {skModule, skPackage}
  case n.kind
  of nkIdent, nkAccQuoted:
    var amb = false
    var ident = considerQuotedIdent(c, n)
    if checkModule in flags:
      result = searchInScopes(c, ident, amb)
-      if result == nil:
-        let candidates = allPureEnumFields(c, ident)
-        if candidates.len > 0:
-          result = candidates[0]
-          amb = candidates.len > 1
-          if amb and checkAmbiguity in flags:
-            errorUseQualifier(c, n.info, candidates)
    else:
-      let candidates = lookUpCandidates(c, ident, allExceptModule)
+      let candidates = searchInScopesFilterBy(c, ident, allExceptModule)
      if candidates.len > 0:
        result = candidates[0]
        amb = candidates.len > 1
@@ -670,47 +626,46 @@ proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
          errorUseQualifier(c, n.info, candidates)
      else:
        result = nil
+    if result == nil:
+      let candidates = allPureEnumFields(c, ident)
+      if candidates.len > 0:
+        result = candidates[0]
+        amb = candidates.len > 1
+        if amb and checkAmbiguity in flags:
+          errorUseQualifier(c, n.info, candidates)
+
    if result == nil and checkUndeclared in flags:
-      result = errorUndeclaredIdentifierHint(c, ident, n.info)
+      result = errorUndeclaredIdentifierHint(c, n, ident)
    elif checkAmbiguity in flags and result != nil and amb:
      result = errorUseQualifier(c, n.info, result, amb)
    c.isAmbiguous = amb
  of nkSym:
    result = n.sym
-  of nkOpenSym:
-    result = qualifiedLookUp(c, n[0], flags)
  of nkDotExpr:
    result = nil
    var m = qualifiedLookUp(c, n[0], (flags * {checkUndeclared}) + {checkModule})
    if m != nil and m.kind == skModule:
      var ident: PIdent = nil
-      if n[1].kind == nkAccQuoted:
+      if n[1].kind == nkIdent:
+        ident = n[1].ident
+      elif n[1].kind == nkAccQuoted:
        ident = considerQuotedIdent(c, n[1])
-      else:
-        # this includes sym and symchoice nodes, but since we are looking in
-        # a module, it shouldn't matter what was captured
-        ident = n[1].getPIdent
      if ident != nil:
        if m == c.module:
-          var ti: TIdentIter = default(TIdentIter)
-          result = initIdentIter(ti, c.topLevelScope.symbols, ident)
-          if result != nil and nextIdentIter(ti, c.topLevelScope.symbols) != nil:
-            # another symbol exists with same name
-            c.isAmbiguous = true
+          result = strTableGet(c.topLevelScope.symbols, ident)
        else:
-          var amb: bool = false
          if c.importModuleLookup.getOrDefault(m.name.id).len > 1:
+            var amb: bool
            result = errorUseQualifier(c, n.info, m, amb)
          else:
-            result = someSymAmb(c.graph, m, ident, amb)
-            if amb: c.isAmbiguous = true
+            result = someSym(c.graph, m, ident)
        if result == nil and checkUndeclared in flags:
-          result = errorUndeclaredIdentifierHint(c, ident, n[1].info)
+          result = errorUndeclaredIdentifierHint(c, n[1], ident)
      elif n[1].kind == nkSym:
        result = n[1].sym
        if result.owner != nil and result.owner != m and checkUndeclared in flags:
          # dotExpr in templates can end up here
-          result = errorUndeclaredIdentifierHint(c, result.name, n[1].info)
+          result = errorUndeclaredIdentifierHint(c, n[1], considerQuotedIdent(c, n[1]))
      elif checkUndeclared in flags and
           n[1].kind notin {nkOpenSymChoice, nkClosedSymChoice}:
        localError(c.config, n[1].info, "identifier expected, but got: " &
@@ -722,10 +677,6 @@ proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
    if result != nil and result.kind == skStub: loadStub(result)

 proc initOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
-  if n.kind == nkOpenSym:
-    # maybe the logic in semexprs should be mirrored here instead
-    # for now it only seems this is called for `pickSym` in `getTypeIdent`
-    return initOverloadIter(o, c, n[0])
  o.importIdx = -1
  o.marked = initIntSet()
  case n.kind
--- a/compiler/lowerings.nim
+++ b/compiler/lowerings.nim
@@ -19,7 +19,7 @@ when defined(nimPreviewSlimSystem):
  import std/assertions

 proc newDeref*(n: PNode): PNode {.inline.} =
-  result = newNodeIT(nkHiddenDeref, n.info, n.typ.elementType)
+  result = newNodeIT(nkHiddenDeref, n.info, n.typ[0])
  result.add n

 proc newTupleAccess*(g: ModuleGraph; tup: PNode, i: int): PNode =
@@ -174,12 +174,12 @@ proc rawIndirectAccess*(a: PNode; field: PSym; info: TLineInfo): PNode =
  # returns a[].field as a node
  assert field.kind == skField
  var deref = newNodeI(nkHiddenDeref, info)
-  deref.typ() = a.typ.skipTypes(abstractInst)[0]
+  deref.typ = a.typ.skipTypes(abstractInst)[0]
  deref.add a
  result = newNodeI(nkDotExpr, info)
  result.add deref
  result.add newSymNode(field)
-  result.typ() = field.typ
+  result.typ = field.typ

 proc rawDirectAccess*(obj, field: PSym): PNode =
  # returns a.field as a node
@@ -187,7 +187,7 @@ proc rawDirectAccess*(obj, field: PSym): PNode =
  result = newNodeI(nkDotExpr, field.info)
  result.add newSymNode(obj)
  result.add newSymNode(field)
-  result.typ() = field.typ
+  result.typ = field.typ

 proc lookupInRecord(n: PNode, id: ItemId): PSym =
  result = nil
@@ -250,19 +250,19 @@ proc newDotExpr*(obj, b: PSym): PNode =
  assert field != nil, b.name.s
  result.add newSymNode(obj)
  result.add newSymNode(field)
-  result.typ() = field.typ
+  result.typ = field.typ

 proc indirectAccess*(a: PNode, b: ItemId, info: TLineInfo): PNode =
  # returns a[].b as a node
  var deref = newNodeI(nkHiddenDeref, info)
-  deref.typ() = a.typ.skipTypes(abstractInst).elementType
+  deref.typ = a.typ.skipTypes(abstractInst)[0]
  var t = deref.typ.skipTypes(abstractInst)
  var field: PSym
  while true:
    assert t.kind == tyObject
    field = lookupInRecord(t.n, b)
    if field != nil: break
-    t = t.baseClass
+    t = t[0]
    if t == nil: break
    t = t.skipTypes(skipPtrs)
  #if field == nil:
@@ -273,12 +273,12 @@ proc indirectAccess*(a: PNode, b: ItemId, info: TLineInfo): PNode =
  result = newNodeI(nkDotExpr, info)
  result.add deref
  result.add newSymNode(field)
-  result.typ() = field.typ
+  result.typ = field.typ

 proc indirectAccess*(a: PNode, b: string, info: TLineInfo; cache: IdentCache): PNode =
  # returns a[].b as a node
  var deref = newNodeI(nkHiddenDeref, info)
-  deref.typ() = a.typ.skipTypes(abstractInst).elementType
+  deref.typ = a.typ.skipTypes(abstractInst)[0]
  var t = deref.typ.skipTypes(abstractInst)
  var field: PSym
  let bb = getIdent(cache, b)
@@ -286,7 +286,7 @@ proc indirectAccess*(a: PNode, b: string, info: TLineInfo; cache: IdentCache): P
    assert t.kind == tyObject
    field = getSymFromList(t.n, bb)
    if field != nil: break
-    t = t.baseClass
+    t = t[0]
    if t == nil: break
    t = t.skipTypes(skipPtrs)
  #if field == nil:
@@ -297,7 +297,7 @@ proc indirectAccess*(a: PNode, b: string, info: TLineInfo; cache: IdentCache): P
  result = newNodeI(nkDotExpr, info)
  result.add deref
  result.add newSymNode(field)
-  result.typ() = field.typ
+  result.typ = field.typ

 proc getFieldFromObj*(t: PType; v: PSym): PSym =
  assert v.kind != skField
@@ -306,7 +306,7 @@ proc getFieldFromObj*(t: PType; v: PSym): PSym =
    assert t.kind == tyObject
    result = lookupInRecord(t.n, v.itemId)
    if result != nil: break
-    t = t.baseClass
+    t = t[0]
    if t == nil: break
    t = t.skipTypes(skipPtrs)

@@ -320,12 +320,12 @@ proc indirectAccess*(a, b: PSym, info: TLineInfo): PNode =
 proc genAddrOf*(n: PNode; idgen: IdGenerator; typeKind = tyPtr): PNode =
  result = newNodeI(nkAddr, n.info, 1)
  result[0] = n
-  result.typ() = newType(typeKind, idgen, n.typ.owner)
+  result.typ = newType(typeKind, idgen, n.typ.owner)
  result.typ.rawAddSon(n.typ)

 proc genDeref*(n: PNode; k = nkHiddenDeref): PNode =
  result = newNodeIT(k, n.info,
-                     n.typ.skipTypes(abstractInst).elementType)
+                     n.typ.skipTypes(abstractInst)[0])
  result.add n

 proc callCodegenProc*(g: ModuleGraph; name: string;
@@ -344,18 +344,18 @@ proc callCodegenProc*(g: ModuleGraph; name: string;
    if optionalArgs != nil:
      for i in 1..<optionalArgs.len-2:
        result.add optionalArgs[i]
-    result.typ() = sym.typ.returnType
+    result.typ = sym.typ[0]

 proc newIntLit*(g: ModuleGraph; info: TLineInfo; value: BiggestInt): PNode =
  result = nkIntLit.newIntNode(value)
-  result.typ() = getSysType(g, info, tyInt)
+  result.typ = getSysType(g, info, tyInt)

 proc genHigh*(g: ModuleGraph; n: PNode): PNode =
  if skipTypes(n.typ, abstractVar).kind == tyArray:
    result = newIntLit(g, n.info, toInt64(lastOrd(g.config, skipTypes(n.typ, abstractVar))))
  else:
    result = newNodeI(nkCall, n.info, 2)
-    result.typ() = getSysType(g, n.info, tyInt)
+    result.typ = getSysType(g, n.info, tyInt)
    result[0] = newSymNode(getSysMagic(g, n.info, "high", mHigh))
    result[1] = n

@@ -364,7 +364,7 @@ proc genLen*(g: ModuleGraph; n: PNode): PNode =
    result = newIntLit(g, n.info, toInt64(lastOrd(g.config, skipTypes(n.typ, abstractVar)) + 1))
  else:
    result = newNodeI(nkCall, n.info, 2)
-    result.typ() = getSysType(g, n.info, tyInt)
+    result.typ = getSysType(g, n.info, tyInt)
    result[0] = newSymNode(getSysMagic(g, n.info, "len", mLengthSeq))
    result[1] = n

--- a/compiler/magicsys.nim
+++ b/compiler/magicsys.nim
@@ -35,7 +35,7 @@ proc getSysMagic*(g: ModuleGraph; info: TLineInfo; name: string, m: TMagic): PSy
  for r in systemModuleSyms(g, id):
    if r.magic == m:
      # prefer the tyInt variant:
-      if r.typ.returnType != nil and r.typ.returnType.kind == tyInt: return r
+      if r.typ[0] != nil and r.typ[0].kind == tyInt: return r
      result = r
  if result != nil: return result
  localError(g.config, info, "system module needs: " & name)
@@ -166,4 +166,4 @@ proc makeAddr*(n: PNode; idgen: IdGenerator): PNode =
    result = n
  else:
    result = newTree(nkHiddenAddr, n)
-    result.typ() = makePtrType(n.typ, idgen)
+    result.typ = makePtrType(n.typ, idgen)
--- a/compiler/main.nim
+++ b/compiler/main.nim
@@ -22,6 +22,8 @@ import
  modules,
  modulegraphs, lineinfos, pathutils, vmprofiler

+# ensure NIR compiles:
+import nir / nir

 when defined(nimPreviewSlimSystem):
  import std/[syncio, assertions]
@@ -46,6 +48,9 @@ proc writeDepsFile(g: ModuleGraph) =
      f.writeLine(toFullPath(g.config, k))
  f.close()

+proc writeNinjaFile(g: ModuleGraph) =
+  discard "to implement"
+
 proc writeCMakeDepsFile(conf: ConfigRef) =
  ## write a list of C files for build systems like CMake.
  ## only updated when the C file list changes.
@@ -150,12 +155,32 @@ proc commandCompileToC(graph: ModuleGraph) =
    extccomp.callCCompiler(conf)
    # for now we do not support writing out a .json file with the build instructions when HCR is on
    if not conf.hcrOn:
-      extccomp.writeJsonBuildInstructions(conf, graph.cachedFiles)
+      extccomp.writeJsonBuildInstructions(conf)
    if optGenScript in graph.config.globalOptions:
      writeDepsFile(graph)
    if optGenCDeps in graph.config.globalOptions:
      writeCMakeDepsFile(conf)

+proc commandCompileToNir(graph: ModuleGraph) =
+  let conf = graph.config
+  extccomp.initVars(conf)
+  if conf.symbolFiles == disabledSf:
+    if {optRun, optForceFullMake} * conf.globalOptions == {optRun}:
+      if not changeDetectedViaJsonBuildInstructions(conf, conf.jsonBuildInstructionsFile):
+        # nothing changed
+        graph.config.notes = graph.config.mainPackageNotes
+        return
+
+  if not extccomp.ccHasSaneOverflow(conf):
+    conf.symbols.defineSymbol("nimEmulateOverflowChecks")
+
+  if conf.symbolFiles == disabledSf:
+    setPipeLinePass(graph, NirPass)
+  else:
+    setPipeLinePass(graph, SemPass)
+  compilePipelineProject(graph)
+  writeNinjaFile(graph)
+
 proc commandJsonScript(graph: ModuleGraph) =
  extccomp.runJsonBuildInstructions(graph.config, graph.config.jsonBuildInstructionsFile)

@@ -172,13 +197,16 @@ proc commandCompileToJS(graph: ModuleGraph) =
    if optGenScript in conf.globalOptions:
      writeDepsFile(graph)

-proc commandInteractive(graph: ModuleGraph) =
+proc commandInteractive(graph: ModuleGraph; useNir: bool) =
  graph.config.setErrorMaxHighMaybe
  initDefines(graph.config.symbols)
-  defineSymbol(graph.config.symbols, "nimscript")
+  if useNir:
+    defineSymbol(graph.config.symbols, "noSignalHandler")
+  else:
+    defineSymbol(graph.config.symbols, "nimscript")
  # note: seems redundant with -d:nimHasLibFFI
  when hasFFI: defineSymbol(graph.config.symbols, "nimffi")
-  setPipeLinePass(graph, InterpreterPass)
+  setPipeLinePass(graph, if useNir: NirReplPass else: InterpreterPass)
  compilePipelineSystemModule(graph)
  if graph.config.commandArgs.len > 0:
    discard graph.compilePipelineModule(fileInfoIdx(graph.config, graph.config.projectFull), {})
@@ -194,7 +222,7 @@ proc commandScan(cache: IdentCache, config: ConfigRef) =
  var stream = llStreamOpen(f, fmRead)
  if stream != nil:
    var
-      L: Lexer = default(Lexer)
+      L: Lexer
      tok: Token = default(Token)
    openLexer(L, f, stream, cache, config)
    while true:
@@ -265,6 +293,8 @@ proc mainCommand*(graph: ModuleGraph) =
        # and it has added this define implictly, so we must undo that here.
        # A better solution might be to fix system.nim
        undefSymbol(conf.symbols, "useNimRtl")
+    of backendNir:
+      if conf.exc == excNone: conf.exc = excGoto
    of backendInvalid: raiseAssert "unreachable"

  proc compileToBackend() =
@@ -275,6 +305,7 @@ proc mainCommand*(graph: ModuleGraph) =
    of backendCpp: commandCompileToC(graph)
    of backendObjc: commandCompileToC(graph)
    of backendJs: commandCompileToJS(graph)
+    of backendNir: commandCompileToNir(graph)
    of backendInvalid: raiseAssert "unreachable"

  template docLikeCmd(body) =
@@ -295,8 +326,7 @@ proc mainCommand*(graph: ModuleGraph) =
    # so by default should not end up in $PWD nor in $projectPath.
    var ret = if optUseNimcache in conf.globalOptions: getNimcacheDir(conf)
              else: conf.projectPath
-    if not ret.string.isAbsolute: # `AbsoluteDir` is not a real guarantee
-      rawMessage(conf, errCannotOpenFile, ret.string & "/")
+    doAssert ret.string.isAbsolute # `AbsoluteDir` is not a real guarantee
    if conf.cmd in cmdDocLike + {cmdRst2html, cmdRst2tex, cmdMd2html, cmdMd2tex}:
      ret = ret / htmldocsDir
    conf.outDir = ret
@@ -413,7 +443,7 @@ proc mainCommand*(graph: ModuleGraph) =
    wantMainModule(conf)
    commandView(graph)
    #msgWriteln(conf, "Beware: Indentation tokens depend on the parser's state!")
-  of cmdInteractive: commandInteractive(graph)
+  of cmdInteractive: commandInteractive(graph, isDefined(conf, "nir"))
  of cmdNimscript:
    if conf.projectIsCmd or conf.projectIsStdin: discard
    elif not fileExists(conf.projectFull):
--- a/compiler/mangleutils.nim
+++ b/compiler/mangleutils.nim
@@ -1,59 +0,0 @@
-import std/strutils
-import ast, modulegraphs
-
-proc mangle*(name: string): string =
-  result = newStringOfCap(name.len)
-  var start = 0
-  if name[0] in Digits:
-    result.add("X" & name[0])
-    start = 1
-  var requiresUnderscore = false
-  template special(x) =
-    result.add x
-    requiresUnderscore = true
-  for i in start..<name.len:
-    let c = name[i]
-    case c
-    of 'a'..'z', '0'..'9', 'A'..'Z':
-      result.add(c)
-    of '_':
-      # we generate names like 'foo_9' for scope disambiguations and so
-      # disallow this here:
-      if i > 0 and i < name.len-1 and name[i+1] in Digits:
-        discard
-      else:
-        result.add(c)
-    of '$': special "dollar"
-    of '%': special "percent"
-    of '&': special "amp"
-    of '^': special "roof"
-    of '!': special "emark"
-    of '?': special "qmark"
-    of '*': special "star"
-    of '+': special "plus"
-    of '-': special "minus"
-    of '/': special "slash"
-    of '\\': special "backslash"
-    of '=': special "eq"
-    of '<': special "lt"
-    of '>': special "gt"
-    of '~': special "tilde"
-    of ':': special "colon"
-    of '.': special "dot"
-    of '@': special "at"
-    of '|': special "bar"
-    else:
-      result.add("X" & toHex(ord(c), 2))
-      requiresUnderscore = true
-  if requiresUnderscore:
-    result.add "_"
-
-proc mangleParamExt*(s: PSym): string =
-  result = "_p"
-  result.addInt s.position
-
-proc mangleProcNameExt*(graph: ModuleGraph, s: PSym): string =
-  result = "__"
-  result.add graph.ifaces[s.itemId.module].uniqueName
-  result.add "_u"
-  result.addInt s.itemId.item # s.disamb #
--- a/compiler/modulegraphs.nim
+++ b/compiler/modulegraphs.nim
@@ -11,9 +11,9 @@
 ## represents a complete Nim project. Single modules can either be kept in RAM
 ## or stored in a rod-file.

-import std/[intsets, tables, hashes, strtabs, algorithm, os, strutils, parseutils]
+import std/[intsets, tables, hashes]
 import ../dist/checksums/src/checksums/md5
-import ast, astalgo, options, lineinfos,idents, btrees, ropes, msgs, pathutils, packages, suggestsymdb
+import ast, astalgo, options, lineinfos,idents, btrees, ropes, msgs, pathutils, packages
 import ic / [packed_ast, ic]


@@ -55,6 +55,11 @@ type
    concreteTypes*: seq[FullId]
    inst*: PInstantiation

+  SymInfoPair* = object
+    sym*: PSym
+    info*: TLineInfo
+    isDecl*: bool
+
  PipelinePass* = enum
    NonePass
    SemPass
@@ -62,6 +67,8 @@ type
    CgenPass
    EvalPass
    InterpreterPass
+    NirPass
+    NirReplPass
    GenDependPass
    Docgen2TexPass
    Docgen2JsonPass
@@ -88,7 +95,6 @@ type
    suggestMode*: bool # whether we are in nimsuggest mode or not.
    invalidTransitiveClosure: bool
    interactive*: bool
-    withinSystem*: bool # in system.nim or a module imported by system.nim
    inclToMod*: Table[FileIndex, FileIndex] # mapping of include file to the
                                            # first module that included it
    importStack*: seq[FileIndex]  # The current import stack. Used for detecting recursive
@@ -102,7 +108,7 @@ type
    doStopCompile*: proc(): bool {.closure.}
    usageSym*: PSym # for nimsuggest
    owners*: seq[PSym]
-    suggestSymbols*: SuggestSymbolDatabase
+    suggestSymbols*: Table[FileIndex, seq[SymInfoPair]]
    suggestErrors*: Table[FileIndex, seq[Suggest]]
    methods*: seq[tuple[methods: seq[PSym], dispatcher: PSym]] # needs serialization!
    bucketTable*: CountTable[ItemId]
@@ -134,8 +140,6 @@ type
    idgen*: IdGenerator
    operators*: Operators

-    cachedFiles*: StringTableRef
-
  TPassContext* = object of RootObj # the pass's context
    idgen*: IdGenerator
  PPassContext* = ref TPassContext
@@ -258,7 +262,7 @@ proc nextModuleIter*(mi: var ModuleIter; g: ModuleGraph): PSym =
 iterator allSyms*(g: ModuleGraph; m: PSym): PSym =
  let importHidden = optImportHidden in m.options
  if isCachedModule(g, m):
-    var rodIt: RodIter = default(RodIter)
+    var rodIt: RodIter
    var r = initRodIterAllSyms(rodIt, g.config, g.cache, g.packed, FileIndex m.position, importHidden)
    while r != nil:
      yield r
@@ -275,30 +279,11 @@ proc someSym*(g: ModuleGraph; m: PSym; name: PIdent): PSym =
  else:
    result = strTableGet(g.ifaces[m.position].interfSelect(importHidden), name)

-proc someSymAmb*(g: ModuleGraph; m: PSym; name: PIdent; amb: var bool): PSym =
-  let importHidden = optImportHidden in m.options
-  if isCachedModule(g, m):
-    result = nil
-    for s in interfaceSymbols(g.config, g.cache, g.packed, FileIndex(m.position), name, importHidden):
-      if result == nil:
-        # set result to the first symbol
-        result = s
-      else:
-        # another symbol found
-        amb = true
-        break
-  else:
-    var ti: TIdentIter = default(TIdentIter)
-    result = initIdentIter(ti, g.ifaces[m.position].interfSelect(importHidden), name)
-    if result != nil and nextIdentIter(ti, g.ifaces[m.position].interfSelect(importHidden)) != nil:
-      # another symbol exists with same name
-      amb = true
-
 proc systemModuleSym*(g: ModuleGraph; name: PIdent): PSym =
  result = someSym(g, g.systemModule, name)

 iterator systemModuleSyms*(g: ModuleGraph; name: PIdent): PSym =
-  var mi: ModuleIter = default(ModuleIter)
+  var mi: ModuleIter
  var r = initModuleIter(mi, g, g.systemModule, name)
  while r != nil:
    yield r
@@ -329,7 +314,7 @@ proc resolveInst(g: ModuleGraph; t: var LazyInstantiation): PInstantiation =
    t.inst = result
  assert result != nil

-proc resolveAttachedOp*(g: ModuleGraph; t: var LazySym): PSym =
+proc resolveAttachedOp(g: ModuleGraph; t: var LazySym): PSym =
  result = t.sym
  if result == nil:
    result = loadSymFromId(g.config, g.cache, g.packed, t.id.module, t.id.packed)
@@ -472,49 +457,6 @@ proc createMagic*(g: ModuleGraph; idgen: IdGenerator; name: string, m: TMagic):
 proc createMagic(g: ModuleGraph; name: string, m: TMagic): PSym =
  result = createMagic(g, g.idgen, name, m)

-proc uniqueModuleName*(conf: ConfigRef; m: PSym): string =
-  ## The unique module name is guaranteed to only contain {'A'..'Z', 'a'..'z', '0'..'9', '_'}
-  ## so that it is useful as a C identifier snippet.
-  let fid = FileIndex(m.position)
-  let path = AbsoluteFile toFullPath(conf, fid)
-  var isLib = false
-  var rel = ""
-  if path.string.startsWith(conf.libpath.string):
-    isLib = true
-    rel = relativeTo(path, conf.libpath).string
-  else:
-    rel = relativeTo(path, conf.projectPath).string
-
-  if not isLib and not belongsToProjectPackage(conf, m):
-    # special handlings for nimble packages
-    when DirSep == '\\':
-      let rel2 = replace(rel, '\\', '/')
-    else:
-      let rel2 = rel
-    const pkgs2 = "pkgs2/"
-    var start = rel2.find(pkgs2)
-    if start >= 0:
-      start += pkgs2.len
-      start += skipUntil(rel2, {'/'}, start)
-      if start+1 < rel2.len:
-        rel = "pkg/" & rel2[start+1..<rel.len] # strips paths
-
-  let trunc = if rel.endsWith(".nim"): rel.len - len(".nim") else: rel.len
-  result = newStringOfCap(trunc)
-  for i in 0..<trunc:
-    let c = rel[i]
-    case c
-    of 'a'..'z', '0'..'9':
-      result.add c
-    of {os.DirSep, os.AltSep}:
-      result.add 'Z' # because it looks a bit like '/'
-    of '.':
-      result.add 'O' # a circle
-    else:
-      # We mangle upper letters too so that there cannot
-      # be clashes with our special meanings of 'Z' and 'O'
-      result.addInt ord(c)
-
 proc registerModule*(g: ModuleGraph; m: PSym) =
  assert m != nil
  assert m.kind == skModule
@@ -526,7 +468,7 @@ proc registerModule*(g: ModuleGraph; m: PSym) =
    setLen(g.packed.pm, m.position + 1)

  g.ifaces[m.position] = Iface(module: m, converters: @[], patterns: @[],
-                               uniqueName: rope(uniqueModuleName(g.config, m)))
+                               uniqueName: rope(uniqueModuleName(g.config, FileIndex(m.position))))
  initStrTables(g, m)

 proc registerModuleById*(g: ModuleGraph; m: FileIndex) =
@@ -535,21 +477,19 @@ proc registerModuleById*(g: ModuleGraph; m: FileIndex) =
 proc initOperators*(g: ModuleGraph): Operators =
  # These are safe for IC.
  # Public because it's used by DrNim.
-  result = Operators(
-    opLe: createMagic(g, "<=", mLeI),
-    opLt: createMagic(g, "<", mLtI),
-    opAnd: createMagic(g, "and", mAnd),
-    opOr: createMagic(g, "or", mOr),
-    opIsNil: createMagic(g, "isnil", mIsNil),
-    opEq: createMagic(g, "==", mEqI),
-    opAdd: createMagic(g, "+", mAddI),
-    opSub: createMagic(g, "-", mSubI),
-    opMul: createMagic(g, "*", mMulI),
-    opDiv: createMagic(g, "div", mDivI),
-    opLen: createMagic(g, "len", mLengthSeq),
-    opNot: createMagic(g, "not", mNot),
-    opContains: createMagic(g, "contains", mInSet)
-  )
+  result.opLe = createMagic(g, "<=", mLeI)
+  result.opLt = createMagic(g, "<", mLtI)
+  result.opAnd = createMagic(g, "and", mAnd)
+  result.opOr = createMagic(g, "or", mOr)
+  result.opIsNil = createMagic(g, "isnil", mIsNil)
+  result.opEq = createMagic(g, "==", mEqI)
+  result.opAdd = createMagic(g, "+", mAddI)
+  result.opSub = createMagic(g, "-", mSubI)
+  result.opMul = createMagic(g, "*", mMulI)
+  result.opDiv = createMagic(g, "div", mDivI)
+  result.opLen = createMagic(g, "len", mLengthSeq)
+  result.opNot = createMagic(g, "not", mNot)
+  result.opContains = createMagic(g, "contains", mInSet)

 proc initModuleGraphFields(result: ModuleGraph) =
  # A module ID of -1 means that the symbol is not attached to a module at all,
@@ -562,7 +502,7 @@ proc initModuleGraphFields(result: ModuleGraph) =
  result.importStack = @[]
  result.inclToMod = initTable[FileIndex, FileIndex]()
  result.owners = @[]
-  result.suggestSymbols = initTable[FileIndex, SuggestFileSymbolDatabase]()
+  result.suggestSymbols = initTable[FileIndex, seq[SymInfoPair]]()
  result.suggestErrors = initTable[FileIndex, seq[Suggest]]()
  result.methods = @[]
  result.compilerprocs = initStrTable()
@@ -576,7 +516,6 @@ proc initModuleGraphFields(result: ModuleGraph) =
  result.symBodyHashes = initTable[int, SigHash]()
  result.operators = initOperators(result)
  result.emittedTypeInfo = initTable[string, FileIndex]()
-  result.cachedFiles = newStringTable()

 proc newModuleGraph*(cache: IdentCache; config: ConfigRef): ModuleGraph =
  result = ModuleGraph()
@@ -678,6 +617,7 @@ proc markDirty*(g: ModuleGraph; fileIdx: FileIndex) =
  if m != nil:
    g.suggestSymbols.del(fileIdx)
    g.suggestErrors.del(fileIdx)
+    g.resetForBackend
    incl m.flags, sfDirty

 proc unmarkAllDirty*(g: ModuleGraph) =
@@ -740,6 +680,8 @@ proc moduleFromRodFile*(g: ModuleGraph; fileIdx: FileIndex;
 proc configComplete*(g: ModuleGraph) =
  rememberStartupConfig(g.startupPackedConfig, g.config)

+from std/strutils import repeat, `%`
+
 proc onProcessing*(graph: ModuleGraph, fileIdx: FileIndex, moduleStatus: string, fromModule: PSym, ) =
  let conf = graph.config
  let isNimscript = conf.isDefined("nimscript")
@@ -765,14 +707,16 @@ func belongsToStdlib*(graph: ModuleGraph, sym: PSym): bool =
  ## Check if symbol belongs to the 'stdlib' package.
  sym.getPackageSymbol.getPackageId == graph.systemModule.getPackageId

-proc fileSymbols*(graph: ModuleGraph, fileIdx: FileIndex): SuggestFileSymbolDatabase =
-  result = graph.suggestSymbols.getOrDefault(fileIdx, newSuggestFileSymbolDatabase(fileIdx, optIdeExceptionInlayHints in graph.config.globalOptions))
-  doAssert(result.fileIndex == fileIdx)
+proc `==`*(a, b: SymInfoPair): bool =
+  result = a.sym == b.sym and a.info.exactEquals(b.info)
+
+proc fileSymbols*(graph: ModuleGraph, fileIdx: FileIndex): seq[SymInfoPair] =
+  result = graph.suggestSymbols.getOrDefault(fileIdx, @[])

 iterator suggestSymbolsIter*(g: ModuleGraph): SymInfoPair =
  for xs in g.suggestSymbols.values:
-    for i in xs.lineInfo.low..xs.lineInfo.high:
-      yield xs.getSymInfoPair(i)
+    for x in xs:
+      yield x

 iterator suggestErrorsIter*(g: ModuleGraph): Suggest =
  for xs in g.suggestErrors.values:
--- a/compiler/modulepaths.nim
+++ b/compiler/modulepaths.nim
@@ -38,18 +38,11 @@ proc getModuleName*(conf: ConfigRef; n: PNode): string =
          localError(n.info, "only '/' supported with $package notation")
          result = ""
    else:
-      if n0.kind in nkIdentKinds:
-        let ident = n0.getPIdent
-        if ident != nil and ident.s[0] == '/':
-          let modname = getModuleName(conf, n[2])
-          # hacky way to implement 'x / y /../ z':
-          result = getModuleName(conf, n1)
-          result.add renderTree(n0, {renderNoComments}).replace(" ")
-          result.add modname
-        else:
-          result = ""
-      else:
-        result = ""
+      let modname = getModuleName(conf, n[2])
+      # hacky way to implement 'x / y /../ z':
+      result = getModuleName(conf, n1)
+      result.add renderTree(n0, {renderNoComments}).replace(" ")
+      result.add modname
  of nkPrefix:
    when false:
      if n[0].kind == nkIdent and n[0].ident.s == "$":
--- a/compiler/modules.nim
+++ b/compiler/modules.nim
@@ -14,9 +14,6 @@ import
  idents, lexer, syntaxes, modulegraphs,
  lineinfos, pathutils

-import ../dist/checksums/src/checksums/sha1
-import std/strtabs
-
 proc resetSystemArtifacts*(g: ModuleGraph) =
  magicsys.resetSysTypes(g)

@@ -25,7 +22,7 @@ template getModuleIdent(graph: ModuleGraph, filename: AbsoluteFile): PIdent =

 proc partialInitModule*(result: PSym; graph: ModuleGraph; fileIdx: FileIndex; filename: AbsoluteFile) =
  let packSym = getPackage(graph, fileIdx)
-  setOwner(result, packSym)
+  result.owner = packSym
  result.position = int fileIdx

 proc newModule*(graph: ModuleGraph; fileIdx: FileIndex): PSym =
@@ -45,8 +42,6 @@ proc includeModule*(graph: ModuleGraph; s: PSym, fileIdx: FileIndex): PNode =
  result = syntaxes.parseFile(fileIdx, graph.cache, graph.config)
  graph.addDep(s, fileIdx)
  graph.addIncludeDep(s.position.FileIndex, fileIdx)
-  let path = toFullPath(graph.config, fileIdx)
-  graph.cachedFiles[path] = $secureHashFile(path)

 proc wantMainModule*(conf: ConfigRef) =
  if conf.projectFull.isEmpty:
--- a/compiler/msgs.nim
+++ b/compiler/msgs.nim
@@ -60,13 +60,31 @@ proc makeCString*(s: string): Rope =
    toCChar(s[i], result)
  result.add('\"')

+proc makeCCharArray*(s: string): Rope =
+  result = newStringOfCap(int(s.len.toFloat * 1.1) + 1)
+  result.add("{")
+  for i in 0..<s.len:
+    # line wrapping of string litterals in cgen'd code was a bad idea, e.g. causes: bug #16265
+    # It also makes reading c sources or grepping harder, for zero benefit.
+    # const MaxLineLength = 64
+    # if (i + 1) mod MaxLineLength == 0:
+    #   res.add("\"\L\"")
+    if i != 0:
+      result.add ", "
+    result.add '\''
+    toCChar(s[i], result)
+    result.add '\''
+  result.add('}')
+
 proc newFileInfo(fullPath: AbsoluteFile, projPath: RelativeFile): TFileInfo =
-  result = TFileInfo(fullPath: fullPath, projPath: projPath,
-                    shortName: fullPath.extractFilename,
-                    quotedFullName: fullPath.string.makeCString,
-                    lines: @[]
-  )
+  result.fullPath = fullPath
+  #shallow(result.fullPath)
+  result.projPath = projPath
+  #shallow(result.projPath)
+  result.shortName = fullPath.extractFilename
  result.quotedName = result.shortName.makeCString
+  result.quotedFullName = fullPath.string.makeCString
+  result.lines = @[]
  when defined(nimpretty):
    if not result.fullPath.isEmpty:
      try:
@@ -123,18 +141,18 @@ proc fileInfoIdx*(conf: ConfigRef; filename: AbsoluteFile; isKnownFile: var bool
    conf.m.filenameToIndexTbl[canon2] = result

 proc fileInfoIdx*(conf: ConfigRef; filename: AbsoluteFile): FileIndex =
-  var dummy: bool = false
+  var dummy: bool
  result = fileInfoIdx(conf, filename, dummy)

 proc fileInfoIdx*(conf: ConfigRef; filename: RelativeFile; isKnownFile: var bool): FileIndex =
  fileInfoIdx(conf, AbsoluteFile expandFilename(filename.string), isKnownFile)

 proc fileInfoIdx*(conf: ConfigRef; filename: RelativeFile): FileIndex =
-  var dummy: bool = false
+  var dummy: bool
  fileInfoIdx(conf, AbsoluteFile expandFilename(filename.string), dummy)

 proc newLineInfo*(fileInfoIdx: FileIndex, line, col: int): TLineInfo =
-  result = TLineInfo(fileIndex: fileInfoIdx)
+  result.fileIndex = fileInfoIdx
  if line < int high(uint16):
    result.line = uint16(line)
  else:
@@ -429,8 +447,7 @@ To create a stacktrace, rerun compilation with './koch temp $1 <file>', see $2 f
 proc handleError(conf: ConfigRef; msg: TMsgKind, eh: TErrorHandling, s: string, ignoreMsg: bool) =
  if msg in fatalMsgs:
    if conf.cmd == cmdIdeTools: log(s)
-    if conf.cmd != cmdIdeTools or msg != errFatal:
-      quit(conf, msg)
+    quit(conf, msg)
  if msg >= errMin and msg <= errMax or
      (msg in warnMin..hintMax and msg in conf.warningAsErrors and not ignoreMsg):
    inc(conf.errorCounter)
@@ -438,11 +455,7 @@ proc handleError(conf: ConfigRef; msg: TMsgKind, eh: TErrorHandling, s: string,
    if conf.errorCounter >= conf.errorMax:
      # only really quit when we're not in the new 'nim check --def' mode:
      if conf.ideCmd == ideNone:
-        when defined(nimsuggest):
-          #we need to inform the user that something went wrong when initializing NimSuggest
-          raiseRecoverableError(s)
-        else:
-          quit(conf, msg)
+        quit(conf, msg)
    elif eh == doAbort and conf.cmd != cmdIdeTools:
      quit(conf, msg)
    elif eh == doRaise:
@@ -560,10 +573,9 @@ proc liMessage*(conf: ConfigRef; info: TLineInfo, msg: TMsgKind, arg: string,
    ignoreMsg = not conf.hasHint(msg)
    if not ignoreMsg and msg in conf.warningAsErrors:
      title = ErrorTitle
-      color = ErrorColor
    else:
      title = HintTitle
-      color = HintColor
+    color = HintColor
    inc(conf.hintCounter)

  let s = if isRaw: arg else: getMessageStr(msg, arg)
@@ -629,7 +641,7 @@ proc warningDeprecated*(conf: ConfigRef, info: TLineInfo = gCmdLineInfo, msg = "
  message(conf, info, warnDeprecated, msg)

 proc internalErrorImpl(conf: ConfigRef; info: TLineInfo, errMsg: string, info2: InstantiationInfo) =
-  if conf.cmd in {cmdIdeTools, cmdCheck} and conf.structuredErrorHook.isNil: return
+  if conf.cmd == cmdIdeTools and conf.structuredErrorHook.isNil: return
  writeContext(conf, info)
  liMessage(conf, info, errInternal, errMsg, doAbort, info2)

@@ -651,16 +663,13 @@ template lintReport*(conf: ConfigRef; info: TLineInfo, beau, got: string, extraM
  let msg = if optStyleError in conf.globalOptions: errGenerated else: hintName
  liMessage(conf, info, msg, m, doNothing, instLoc())

-proc quotedFilename*(conf: ConfigRef; fi: FileIndex): Rope =
-  if fi.int32 < 0:
+proc quotedFilename*(conf: ConfigRef; i: TLineInfo): Rope =
+  if i.fileIndex.int32 < 0:
    result = makeCString "???"
  elif optExcessiveStackTrace in conf.globalOptions:
-    result = conf.m.fileInfos[fi.int32].quotedFullName
+    result = conf.m.fileInfos[i.fileIndex.int32].quotedFullName
  else:
-    result = conf.m.fileInfos[fi.int32].quotedName
-
-proc quotedFilename*(conf: ConfigRef; i: TLineInfo): Rope =
-  quotedFilename(conf, i.fileIndex)
+    result = conf.m.fileInfos[i.fileIndex.int32].quotedName

 template listMsg(title, r) =
  msgWriteln(conf, title, {msgNoUnitSep})
@@ -669,6 +678,31 @@ template listMsg(title, r) =
 proc listWarnings*(conf: ConfigRef) = listMsg("Warnings:", warnMin..warnMax)
 proc listHints*(conf: ConfigRef) = listMsg("Hints:", hintMin..hintMax)

+proc uniqueModuleName*(conf: ConfigRef; fid: FileIndex): string =
+  ## The unique module name is guaranteed to only contain {'A'..'Z', 'a'..'z', '0'..'9', '_'}
+  ## so that it is useful as a C identifier snippet.
+  let path = AbsoluteFile toFullPath(conf, fid)
+  let rel =
+    if path.string.startsWith(conf.libpath.string):
+      relativeTo(path, conf.libpath).string
+    else:
+      relativeTo(path, conf.projectPath).string
+  let trunc = if rel.endsWith(".nim"): rel.len - len(".nim") else: rel.len
+  result = newStringOfCap(trunc)
+  for i in 0..<trunc:
+    let c = rel[i]
+    case c
+    of 'a'..'z':
+      result.add c
+    of {os.DirSep, os.AltSep}:
+      result.add 'Z' # because it looks a bit like '/'
+    of '.':
+      result.add 'O' # a circle
+    else:
+      # We mangle upper letters and digits too so that there cannot
+      # be clashes with our special meanings of 'Z' and 'O'
+      result.addInt ord(c)
+
 proc genSuccessX*(conf: ConfigRef) =
  let mem =
    when declared(system.getMaxMem): formatSize(getMaxMem()) & " peakmem"
--- a/compiler/ndi.nim
+++ b/compiler/ndi.nim
@@ -0,0 +1,52 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2017 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## This module implements the generation of ``.ndi`` files for better debugging
+## support of Nim code. "ndi" stands for "Nim debug info".
+
+import ast, msgs, ropes, options, pathutils
+
+when defined(nimPreviewSlimSystem):
+  import std/[syncio, assertions]
+
+type
+  NdiFile* = object
+    enabled: bool
+    f: File
+    buf: string
+    filename: AbsoluteFile
+    syms: seq[PSym]
+
+proc doWrite(f: var NdiFile; s: PSym; conf: ConfigRef) =
+  f.buf.setLen 0
+  f.buf.addInt s.info.line.int
+  f.buf.add "\t"
+  f.buf.addInt s.info.col.int
+  f.f.write(s.name.s, "\t")
+  f.f.writeRope(s.loc.r)
+  f.f.writeLine("\t", toFullPath(conf, s.info), "\t", f.buf)
+
+template writeMangledName*(f: NdiFile; s: PSym; conf: ConfigRef) =
+  if f.enabled: f.syms.add s
+
+proc open*(f: var NdiFile; filename: AbsoluteFile; conf: ConfigRef) =
+  f.enabled = not filename.isEmpty
+  if f.enabled:
+    f.filename = filename
+    f.buf = newStringOfCap(20)
+
+proc close*(f: var NdiFile, conf: ConfigRef) =
+  if f.enabled:
+    f.f = open(f.filename.string, fmWrite, 8000)
+    doAssert f.f != nil, f.filename.string
+    for s in f.syms:
+      doWrite(f, s, conf)
+    close(f.f)
+    f.syms.reset
+    f.filename.reset
--- a/compiler/nilcheck.nim
+++ b/compiler/nilcheck.nim
@@ -498,7 +498,7 @@ proc checkCall(n, ctx, map): Check =
  # check args and handle possible mutations

  var isNew = false
-  result = Check(map: map)
+  result.map = map
  for i, child in n:
    discard check(child, ctx, map)

@@ -507,7 +507,7 @@ proc checkCall(n, ctx, map): Check =
      # as it might have been mutated
      # TODO similar for normal refs and fields: find dependent exprs: brackets

-      if child.kind == nkHiddenAddr and not child.typ.isNil and child.typ.kind == tyVar and child.typ.elementType.kind == tyRef:
+      if child.kind == nkHiddenAddr and not child.typ.isNil and child.typ.kind == tyVar and child.typ[0].kind == tyRef:
        if not isNew:
          result.map = newNilMap(map)
          isNew = true
@@ -753,7 +753,6 @@ proc checkReturn(n, ctx, map): Check =

 proc checkIf(n, ctx, map): Check =
  ## check branches based on condition
-  result = default(Check)
  var mapIf: NilMap = map

  # first visit the condition
@@ -826,7 +825,7 @@ proc checkFor(n, ctx, map): Check =
  var check2 = check(n.sons[2], ctx, m)
  var map2 = check2.map

-  result = Check(map: ctx.union(map0, m))
+  result.map = ctx.union(map0, m)
  result.map = ctx.union(result.map, map2)
  result.nilability = Safe

@@ -854,7 +853,7 @@ proc checkWhile(n, ctx, map): Check =
  var check2 = check(n.sons[1], ctx, m)
  var map2 = check2.map

-  result = Check(map: ctx.union(map0, map1))
+  result.map = ctx.union(map0, map1)
  result.map = ctx.union(result.map, map2)
  result.nilability = Safe

@@ -900,7 +899,7 @@ proc checkInfix(n, ctx, map): Check =
 proc checkIsNil(n, ctx, map; isElse: bool = false): Check =
  ## check isNil calls
  ## update the map depending on if it is not isNil or isNil
-  result = Check(map: newNilMap(map))
+  result.map = newNilMap(map)
  let value = n[1]
  result.map.store(ctx, ctx.index(n[1]), if not isElse: Nil else: Safe, TArg, n.info, n)

@@ -919,7 +918,7 @@ proc infix(ctx: NilCheckerContext, l: PNode, r: PNode, magic: TMagic): PNode =
    newSymNode(op, r.info),
    l,
    r)
-  result.typ() = newType(tyBool, ctx.idgen, nil)
+  result.typ = newType(tyBool, ctx.idgen, nil)

 proc prefixNot(ctx: NilCheckerContext, node: PNode): PNode =
  var cache = newIdentCache()
@@ -929,7 +928,7 @@ proc prefixNot(ctx: NilCheckerContext, node: PNode): PNode =
  result = nkPrefix.newTree(
    newSymNode(op, node.info),
    node)
-  result.typ() = newType(tyBool, ctx.idgen, nil)
+  result.typ = newType(tyBool, ctx.idgen, nil)

 proc infixEq(ctx: NilCheckerContext, l: PNode, r: PNode): PNode =
  infix(ctx, l, r, mEqRef)
@@ -948,7 +947,7 @@ proc checkCase(n, ctx, map): Check =
  #   c2
  # also a == true is a , a == false is not a
  let base = n[0]
-  result = Check(map: map.copyMap())
+  result.map = map.copyMap()
  result.nilability = Safe
  var a: PNode = nil
  for child in n:
@@ -1220,7 +1219,7 @@ proc check(n: PNode, ctx: NilCheckerContext, map: NilMap): Check =
    result = check(n.sons[1], ctx, map)
  of nkStmtList, nkStmtListExpr, nkChckRangeF, nkChckRange64, nkChckRange,
     nkBracket, nkCurly, nkPar, nkTupleConstr, nkClosure, nkObjConstr, nkElse:
-    result = Check(map: map)
+    result.map = map
    if n.kind in {nkObjConstr, nkTupleConstr}:
      # TODO deeper nested elements?
      # A(field: B()) #
@@ -1247,10 +1246,10 @@ proc check(n: PNode, ctx: NilCheckerContext, map: NilMap): Check =
    result = checkIf(n, ctx, map)
  of nkAsgn, nkFastAsgn, nkSinkAsgn:
    result = checkAsgn(n[0], n[1], ctx, map)
-  of nkVarSection, nkLetSection:
-    result = Check(map: map)
+  of nkVarSection:
+    result.map = map
    for child in n:
-      result = checkAsgn(child[0].skipPragmaExpr, child[2], ctx, result.map)
+      result = checkAsgn(child[0], child[2], ctx, result.map)
  of nkForStmt:
    result = checkFor(n, ctx, map)
  of nkCaseStmt:
@@ -1274,7 +1273,8 @@ proc check(n: PNode, ctx: NilCheckerContext, map: NilMap): Check =
  else:

    var elementMap = map.copyMap()
-    var elementCheck = Check(map: elementMap)
+    var elementCheck: Check
+    elementCheck.map = elementMap
    for element in n:
      elementCheck = check(element, ctx, elementCheck.map)

@@ -1367,7 +1367,7 @@ proc checkNil*(s: PSym; body: PNode; conf: ConfigRef, idgen: IdGenerator) =
        continue
      map.store(context, context.index(child), typeNilability(child.typ), TArg, child.info, child)

-  map.store(context, resultExprIndex, if not s.typ.returnType.isNil and s.typ.returnType.kind == tyRef: Nil else: Safe, TResult, s.ast.info)
+  map.store(context, resultExprIndex, if not s.typ[0].isNil and s.typ[0].kind == tyRef: Nil else: Safe, TResult, s.ast.info)

  # echo "checking ", s.name.s, " ", filename

@@ -1383,5 +1383,5 @@ proc checkNil*(s: PSym; body: PNode; conf: ConfigRef, idgen: IdGenerator) =
  # (ANotNil, BNotNil) :
  # do we check on asgn nilability at all?

-  if not s.typ.returnType.isNil and s.typ.returnType.kind == tyRef and tfNotNil in s.typ.returnType.flags:
+  if not s.typ[0].isNil and s.typ[0].kind == tyRef and tfNotNil in s.typ[0].flags:
    checkResult(s.ast, context, res.map)
--- a/compiler/nim.cfg
+++ b/compiler/nim.cfg
@@ -4,13 +4,12 @@ hint[XDeclaredButNotUsed]:off

 define:booting
 define:nimcore
+define:nimPreviewFloatRoundtrip
 define:nimPreviewSlimSystem
 define:nimPreviewCstringConversion
 define:nimPreviewProcConversion
 define:nimPreviewRangeDefault
 define:nimPreviewNonVarDestructor
-define:nimPreviewCheckedClose
-define:nimPreviewAsmSemSymbol
 threads:off

 #import:"$projectpath/testability"
--- a/compiler/nim.nim
+++ b/compiler/nim.nim
@@ -116,9 +116,8 @@ proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
    conf.backend = backendC

  if conf.selectedGC == gcUnselected:
-    if conf.backend in {backendC, backendCpp, backendObjc} or
-        (conf.cmd in cmdDocLike and conf.backend != backendJs) or
-        conf.cmd == cmdGendepend:
+    if conf.backend in {backendC, backendCpp, backendObjc, backendNir} or
+        (conf.cmd == cmdInteractive and isDefined(conf, "nir")):
      initOrcDefines(conf)

  mainCommand(graph)
--- a/compiler/nimblecmd.nim
+++ b/compiler/nimblecmd.nim
@@ -79,8 +79,6 @@ proc getPathVersionChecksum*(p: string): tuple[name, version, checksum: string]
  ## ``/home/user/.nimble/pkgs/package-0.1-febadeaea2345e777f0f6f8433f7f0a52edd5d1b`` into
  ## ``("/home/user/.nimble/pkgs/package", "0.1", "febadeaea2345e777f0f6f8433f7f0a52edd5d1b")``

-  result = ("", "", "")
-
  const checksumSeparator = '-'
  const versionSeparator = '-'
  const specialVersionSepartator = "-#"
--- a/compiler/nimconf.nim
+++ b/compiler/nimconf.nim
@@ -223,7 +223,7 @@ proc readConfigFile*(filename: AbsoluteFile; cache: IdentCache;
  stream = llStreamOpen(filename, fmRead)
  if stream != nil:
    openLexer(L, filename, stream, cache, config)
-    tok = Token(tokType: tkEof)       # to avoid a pointless warning
+    tok.tokType = tkEof       # to avoid a pointless warning
    var condStack: seq[bool] = @[]
    confTok(L, tok, config, condStack)           # read in the first token
    while tok.tokType != tkEof: parseAssignment(L, tok, config, filename, condStack)
--- a/compiler/nimeval.nim
+++ b/compiler/nimeval.nim
@@ -11,8 +11,8 @@
 import
  ast, modules, condsyms,
  options, llstream, lineinfos, vm,
-  vmdef, modulegraphs, idents, pathutils,
-  scriptconfig, std/[compilesettings, tables, os]
+  vmdef, modulegraphs, idents, os, pathutils,
+  scriptconfig, std/[compilesettings, tables]

 import pipelines

@@ -40,7 +40,7 @@ proc selectUniqueSymbol*(i: Interpreter; name: string;
  assert i != nil
  assert i.mainModule != nil, "no main module selected"
  let n = getIdent(i.graph.cache, name)
-  var it: ModuleIter = default(ModuleIter)
+  var it: ModuleIter
  var s = initModuleIter(it, i.graph, i.mainModule, n)
  result = nil
  while s != nil:
--- a/compiler/nimsets.nim
+++ b/compiler/nimsets.nim
@@ -65,7 +65,7 @@ proc toBitSet*(conf: ConfigRef; s: PNode): TBitSet =
  result = @[]
  var first: Int128 = Zero
  var j: Int128 = Zero
-  first = firstOrd(conf, s.typ.elementType)
+  first = firstOrd(conf, s.typ[0])
  bitSetInit(result, int(getSize(conf, s.typ)))
  for i in 0..<s.len:
    if s[i].kind == nkRange:
@@ -84,7 +84,7 @@ proc toTreeSet*(conf: ConfigRef; s: TBitSet, settype: PType, info: TLineInfo): P
  elemType = settype[0]
  first = firstOrd(conf, elemType).toInt64
  result = newNodeI(nkCurly, info)
-  result.typ() = settype
+  result.typ = settype
  result.info = info
  e = 0
  while e < s.len * ElemSize:
@@ -101,7 +101,7 @@ proc toTreeSet*(conf: ConfigRef; s: TBitSet, settype: PType, info: TLineInfo): P
        result.add aa
      else:
        n = newNodeI(nkRange, info)
-        n.typ() = elemType
+        n.typ = elemType
        n.add aa
        let bb = newIntTypeNode(b + first, elemType)
        bb.info = info
--- a/compiler/nir/ast2ir.nim
+++ b/compiler/nir/ast2ir.nim
--- a/compiler/nir/cir.nim
+++ b/compiler/nir/cir.nim
@@ -0,0 +1,983 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# We produce C code as a list of tokens.
+
+import std / [assertions, syncio, tables, intsets, formatfloat]
+from std / strutils import toOctal
+import .. / ic / [bitabs, rodfiles]
+import nirtypes, nirinsts, nirfiles
+import ../../dist/checksums/src/checksums/md5
+
+type
+  Token = LitId # indexing into the tokens BiTable[string]
+
+  PredefinedToken = enum
+    IgnoreMe = "<unused>"
+    EmptyToken = ""
+    CurlyLe = "{"
+    CurlyRi = "}"
+    ParLe = "("
+    ParRi = ")"
+    BracketLe = "["
+    BracketRi = "]"
+    NewLine = "\n"
+    Semicolon = ";"
+    Comma = ", "
+    Space = " "
+    Colon = ": "
+    Dot = "."
+    Arrow = "->"
+    Star = "*"
+    Amp = "&"
+    AsgnOpr = " = "
+    ScopeOpr = "::"
+    ConstKeyword = "const "
+    StaticKeyword = "static "
+    ExternKeyword = "extern "
+    WhileKeyword = "while "
+    IfKeyword = "if ("
+    ElseKeyword = "else "
+    SwitchKeyword = "switch "
+    CaseKeyword = "case "
+    DefaultKeyword = "default:"
+    BreakKeyword = "break"
+    NullPtr = "nullptr"
+    IfNot = "if (!("
+    ReturnKeyword = "return "
+    TypedefStruct = "typedef struct "
+    TypedefUnion = "typedef union "
+    IncludeKeyword = "#include "
+
+proc fillTokenTable(tab: var BiTable[string]) =
+  for e in EmptyToken..high(PredefinedToken):
+    let id = tab.getOrIncl $e
+    assert id == LitId(e), $(id, " ", ord(e))
+
+type
+  GeneratedCode* = object
+    m: NirModule
+    includes: seq[LitId]
+    includedHeaders: IntSet
+    data: seq[LitId]
+    protos: seq[LitId]
+    code: seq[LitId]
+    init: seq[LitId]
+    tokens: BiTable[string]
+    emittedStrings: IntSet
+    needsPrefix: IntSet
+    generatedTypes: IntSet
+    mangledModules: Table[LitId, LitId]
+
+proc initGeneratedCode*(m: sink NirModule): GeneratedCode =
+  result = GeneratedCode(m: m, code: @[], tokens: initBiTable[string]())
+  fillTokenTable(result.tokens)
+
+proc add*(g: var GeneratedCode; t: PredefinedToken) {.inline.} =
+  g.code.add Token(t)
+
+proc add*(g: var GeneratedCode; s: string) {.inline.} =
+  g.code.add g.tokens.getOrIncl(s)
+
+proc mangleModuleName(c: var GeneratedCode; key: LitId): LitId =
+  result = c.mangledModules.getOrDefault(key, LitId(0))
+  if result == LitId(0):
+    let u {.cursor.} = c.m.lit.strings[key]
+    var last = u.len - len(".nim") - 1
+    var start = last
+    while start >= 0 and u[start] != '/': dec start
+    var sum = getMD5(u)
+    sum.setLen(8)
+    let dest = u.substr(start+1, last) & sum
+    result = c.tokens.getOrIncl(dest)
+    c.mangledModules[key] = result
+
+type
+  CppFile = object
+    f: File
+
+proc write(f: var CppFile; s: string) = write(f.f, s)
+proc write(f: var CppFile; c: char) = write(f.f, c)
+
+proc writeTokenSeq(f: var CppFile; s: seq[Token]; c: GeneratedCode) =
+  var indent = 0
+  for i in 0..<s.len:
+    let x = s[i]
+    case x
+    of Token(CurlyLe):
+      inc indent
+      write f, c.tokens[x]
+      write f, "\n"
+      for i in 1..indent*2: write f, ' '
+    of Token(CurlyRi):
+      dec indent
+      write f, c.tokens[x]
+      if i+1 < s.len and s[i+1] == Token(CurlyRi):
+        discard
+      else:
+        write f, "\n"
+        for i in 1..indent*2: write f, ' '
+    of Token(Semicolon):
+      write f, c.tokens[x]
+      if i+1 < s.len and s[i+1] == Token(CurlyRi):
+        discard "no newline before }"
+      else:
+        write f, "\n"
+        for i in 1..indent*2: write f, ' '
+    of Token(NewLine):
+      write f, c.tokens[x]
+      for i in 1..indent*2: write f, ' '
+    else:
+      write f, c.tokens[x]
+
+
+# Type graph
+
+type
+  TypeList = object
+    processed: IntSet
+    s: seq[(TypeId, PredefinedToken)]
+
+proc add(dest: var TypeList; elem: TypeId; decl: PredefinedToken) =
+  if not containsOrIncl(dest.processed, int(elem)):
+    dest.s.add (elem, decl)
+
+type
+  TypeOrder = object
+    forwardedDecls, ordered: TypeList
+    typeImpls: Table[string, TypeId]
+    lookedAt: IntSet
+
+proc traverseObject(types: TypeGraph; lit: Literals; c: var TypeOrder; t: TypeId)
+
+proc recordDependency(types: TypeGraph; lit: Literals; c: var TypeOrder; parent, child: TypeId) =
+  var ch = child
+  var viaPointer = false
+  while true:
+    case types[ch].kind
+    of APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy:
+      viaPointer = true
+      ch = elementType(types, ch)
+    of LastArrayTy:
+      ch = elementType(types, ch)
+    else:
+      break
+
+  case types[ch].kind
+  of ObjectTy, UnionTy:
+    let decl = if types[ch].kind == ObjectTy: TypedefStruct else: TypedefUnion
+    let obj = c.typeImpls.getOrDefault(lit.strings[types[ch].litId])
+    if viaPointer:
+      c.forwardedDecls.add obj, decl
+    else:
+      if not containsOrIncl(c.lookedAt, obj.int):
+        traverseObject(types, lit, c, obj)
+      c.ordered.add obj, decl
+  of ArrayTy:
+    if viaPointer:
+      c.forwardedDecls.add ch, TypedefStruct
+    else:
+      if not containsOrIncl(c.lookedAt, ch.int):
+        traverseObject(types, lit, c, ch)
+      c.ordered.add ch, TypedefStruct
+  else:
+    discard "uninteresting type as we only focus on the required struct declarations"
+
+proc traverseObject(types: TypeGraph; lit: Literals; c: var TypeOrder; t: TypeId) =
+  for x in sons(types, t):
+    case types[x].kind
+    of FieldDecl:
+      recordDependency types, lit, c, t, x.firstSon
+    of ObjectTy:
+      # inheritance
+      recordDependency types, lit, c, t, x
+    else: discard
+
+proc traverseTypes(types: TypeGraph; lit: Literals; c: var TypeOrder) =
+  for t in allTypes(types):
+    if types[t].kind in {ObjectDecl, UnionDecl}:
+      assert types[t.firstSon].kind == NameVal
+      c.typeImpls[lit.strings[types[t.firstSon].litId]] = t
+
+  for t in allTypesIncludingInner(types):
+    case types[t].kind
+    of ObjectDecl, UnionDecl:
+      traverseObject types, lit, c, t
+      let decl = if types[t].kind == ObjectDecl: TypedefStruct else: TypedefUnion
+      c.ordered.add t, decl
+    of ArrayTy:
+      traverseObject types, lit, c, t
+      c.ordered.add t, TypedefStruct
+    else: discard
+
+when false:
+  template emitType(s: string) = c.types.add c.tokens.getOrIncl(s)
+  template emitType(t: Token) = c.types.add t
+  template emitType(t: PredefinedToken) = c.types.add Token(t)
+
+proc genType(g: var GeneratedCode; types: TypeGraph; lit: Literals; t: TypeId; name = "") =
+  template maybeAddName =
+    if name != "":
+      g.add Space
+      g.add name
+
+  template atom(s: string) =
+    g.add s
+    maybeAddName()
+  case types[t].kind
+  of VoidTy: atom "void"
+  of IntTy: atom "NI" & $types[t].integralBits
+  of UIntTy: atom "NU" & $types[t].integralBits
+  of FloatTy: atom "NF" & $types[t].integralBits
+  of BoolTy: atom "NB" & $types[t].integralBits
+  of CharTy: atom "NC" & $types[t].integralBits
+  of ObjectTy, UnionTy, NameVal, AnnotationVal:
+    atom lit.strings[types[t].litId]
+  of VarargsTy:
+    g.add "..."
+  of APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy:
+    genType g, types, lit, elementType(types, t)
+    g.add Star
+    maybeAddName()
+  of ArrayTy:
+    genType g, types, lit, arrayName(types, t)
+    maybeAddName()
+  of LastArrayTy:
+    genType g, types, lit, elementType(types, t)
+    maybeAddName()
+    g.add BracketLe
+    g.add BracketRi
+  of ProcTy:
+    let (retType, callConv) = returnType(types, t)
+    genType g, types, lit, retType
+    g.add Space
+    g.add ParLe
+    genType g, types, lit, callConv
+    g.add Star # "(*fn)"
+    maybeAddName()
+    g.add ParRi
+    g.add ParLe
+    var i = 0
+    for ch in params(types, t):
+      if i > 0: g.add Comma
+      genType g, types, lit, ch
+      inc i
+    g.add ParRi
+  of ObjectDecl, UnionDecl:
+    atom lit.strings[types[t.firstSon].litId]
+  of IntVal, SizeVal, AlignVal, OffsetVal, FieldDecl:
+    #raiseAssert "did not expect: " & $types[t].kind
+    g.add "BUG "
+    atom $types[t].kind
+
+proc generateTypes(g: var GeneratedCode; types: TypeGraph; lit: Literals; c: TypeOrder) =
+  for (t, declKeyword) in c.forwardedDecls.s:
+    let name = if types[t].kind == ArrayTy: arrayName(types, t) else: t.firstSon
+    let s {.cursor.} = lit.strings[types[name].litId]
+    g.add declKeyword
+    g.add s
+    g.add Space
+    g.add s
+    g.add Semicolon
+
+  for (t, declKeyword) in c.ordered.s:
+    let name = if types[t].kind == ArrayTy: arrayName(types, t) else: t.firstSon
+    let litId = types[name].litId
+    if not g.generatedTypes.containsOrIncl(litId.int):
+      let s {.cursor.} = lit.strings[litId]
+      g.add declKeyword
+      g.add CurlyLe
+      if types[t].kind == ArrayTy:
+        genType g, types, lit, elementType(types, t), "a"
+        g.add BracketLe
+        g.add $arrayLen(types, t)
+        g.add BracketRi
+        g.add Semicolon
+      else:
+        var i = 0
+        for x in sons(types, t):
+          case types[x].kind
+          of FieldDecl:
+            genType g, types, lit, x.firstSon, "F" & $i
+            g.add Semicolon
+            inc i
+          of ObjectTy:
+            genType g, types, lit, x, "P"
+            g.add Semicolon
+          else: discard
+      g.add CurlyRi
+      g.add s
+      g.add Semicolon
+
+# Procs
+
+proc toCChar*(c: char; result: var string) {.inline.} =
+  case c
+  of '\0'..'\x1F', '\x7F'..'\xFF':
+    result.add '\\'
+    result.add toOctal(c)
+  of '\'', '\"', '\\', '?':
+    result.add '\\'
+    result.add c
+  else:
+    result.add c
+
+proc makeCString(s: string): string =
+  result = newStringOfCap(s.len + 10)
+  result.add('"')
+  for c in s: toCChar(c, result)
+  result.add('"')
+
+template emitData(s: string) = c.data.add c.tokens.getOrIncl(s)
+template emitData(t: Token) = c.data.add t
+template emitData(t: PredefinedToken) = c.data.add Token(t)
+
+proc genStrLit(c: var GeneratedCode; lit: Literals; litId: LitId): Token =
+  result = Token(c.tokens.getOrIncl "QStr" & $litId)
+  if not containsOrIncl(c.emittedStrings, int(litId)):
+    let s {.cursor.} = lit.strings[litId]
+    emitData "static const struct "
+    emitData CurlyLe
+    emitData "NI cap"
+    emitData Semicolon
+    emitData "NC8 data"
+    emitData BracketLe
+    emitData $s.len
+    emitData "+1"
+    emitData BracketRi
+    emitData Semicolon
+    emitData CurlyRi
+    emitData result
+    emitData AsgnOpr
+    emitData CurlyLe
+    emitData $s.len
+    emitData " | NIM_STRLIT_FLAG"
+    emitData Comma
+    emitData makeCString(s)
+    emitData CurlyRi
+    emitData Semicolon
+
+proc genIntLit(c: var GeneratedCode; lit: Literals; litId: LitId) =
+  let i = lit.numbers[litId]
+  if i > low(int32) and i <= high(int32):
+    c.add $i
+  elif i == low(int32):
+    # Nim has the same bug for the same reasons :-)
+    c.add "(-2147483647 -1)"
+  elif i > low(int64):
+    c.add "IL64("
+    c.add $i
+    c.add ")"
+  else:
+    c.add "(IL64(-9223372036854775807) - IL64(1))"
+
+proc gen(c: var GeneratedCode; t: Tree; n: NodePos)
+
+proc genDisplayName(c: var GeneratedCode; symId: SymId) =
+  let displayName = c.m.symnames[symId]
+  if displayName != LitId(0):
+    c.add "/*"
+    c.add c.m.lit.strings[displayName]
+    c.add "*/"
+
+proc genSymDef(c: var GeneratedCode; t: Tree; n: NodePos) =
+  if t[n].kind == SymDef:
+    let symId = t[n].symId
+    c.needsPrefix.incl symId.int
+    genDisplayName c, symId
+  gen c, t, n
+
+proc genGlobal(c: var GeneratedCode; t: Tree; name, typ: NodePos; annotation: string) =
+  c.add annotation
+  let m: string
+  if t[name].kind == SymDef:
+    let symId = t[name].symId
+    m = c.tokens[mangleModuleName(c, c.m.namespace)] & "__" & $symId
+    genDisplayName c, symId
+  else:
+    assert t[name].kind == ModuleSymUse
+    let (x, y) = sons2(t, name)
+    m = c.tokens[mangleModuleName(c, t[x].litId)] & "__" & $t[y].immediateVal
+  genType c, c.m.types, c.m.lit, t[typ].typeId, m
+
+proc genLocal(c: var GeneratedCode; t: Tree; name, typ: NodePos; annotation: string) =
+  assert t[name].kind == SymDef
+  c.add annotation
+  let symId = t[name].symId
+  genType c, c.m.types, c.m.lit, t[typ].typeId, "q" & $symId
+  genDisplayName c, symId
+
+proc genProcDecl(c: var GeneratedCode; t: Tree; n: NodePos; isExtern: bool) =
+  let signatureBegin = c.code.len
+  let name = n.firstSon
+
+  var prc = n.firstSon
+  next t, prc
+
+  while true:
+    case t[prc].kind
+    of PragmaPair:
+      let (x, y) = sons2(t, prc)
+      let key = cast[PragmaKey](t[x].rawOperand)
+      case key
+      of HeaderImport:
+        let lit = t[y].litId
+        let headerAsStr {.cursor.} = c.m.lit.strings[lit]
+        let header = c.tokens.getOrIncl(headerAsStr)
+        # headerAsStr can be empty, this has the semantics of the `nodecl` pragma:
+        if headerAsStr.len > 0 and not c.includedHeaders.containsOrIncl(int header):
+          if headerAsStr[0] == '#':
+            discard "skip the #include"
+          else:
+            c.includes.add Token(IncludeKeyword)
+          c.includes.add header
+          c.includes.add Token NewLine
+        # do not generate code for importc'ed procs:
+        return
+      of DllImport:
+        let lit = t[y].litId
+        raiseAssert "cannot eval: " & c.m.lit.strings[lit]
+      else: discard
+    of PragmaId: discard
+    else: break
+    next t, prc
+
+  var resultDeclPos = NodePos(-1)
+  if t[prc].kind == SummonResult:
+    resultDeclPos = prc
+    gen c, t, prc.firstSon
+    next t, prc
+  else:
+    c.add "void"
+  c.add Space
+  genSymDef c, t, name
+  c.add ParLe
+  var params = 0
+  while t[prc].kind == SummonParam:
+    if params > 0: c.add Comma
+    let (typ, sym) = sons2(t, prc)
+    genLocal c, t, sym, typ, ""
+    next t, prc
+    inc params
+  if params == 0:
+    c.add "void"
+  c.add ParRi
+
+  for i in signatureBegin ..< c.code.len:
+    c.protos.add c.code[i]
+  c.protos.add Token Semicolon
+
+  if isExtern:
+    c.code.setLen signatureBegin
+  else:
+    c.add CurlyLe
+    if resultDeclPos.int >= 0:
+      gen c, t, resultDeclPos
+    for ch in sonsRest(t, n, prc):
+      gen c, t, ch
+    c.add CurlyRi
+
+template triop(opr) =
+  let (typ, a, b) = sons3(t, n)
+  c.add ParLe
+  c.add ParLe
+  gen c, t, typ
+  c.add ParRi
+  gen c, t, a
+  c.add opr
+  gen c, t, b
+  c.add ParRi
+
+template cmpop(opr) =
+  let (_, a, b) = sons3(t, n)
+  c.add ParLe
+  gen c, t, a
+  c.add opr
+  gen c, t, b
+  c.add ParRi
+
+template binaryop(opr) =
+  let (typ, a) = sons2(t, n)
+  c.add ParLe
+  c.add ParLe
+  gen c, t, typ
+  c.add ParRi
+  c.add opr
+  gen c, t, a
+  c.add ParRi
+
+template checkedBinaryop(opr) =
+  let (typ, labIdx, a, b) = sons4(t, n)
+  let bits = integralBits(c.m.types[t[typ].typeId])
+  let lab = t[labIdx].label
+
+  c.add (opr & $bits)
+  c.add ParLe
+  c.gen t, a
+  c.add Comma
+  c.gen t, b
+  c.add Comma
+  c.add "L" & $lab.int
+  c.add ParRi
+
+proc genNumberConv(c: var GeneratedCode; t: Tree; n: NodePos) =
+  let (typ, arg) = sons2(t, n)
+  if t[arg].kind == IntVal:
+    let litId = t[arg].litId
+    c.add ParLe
+    c.add ParLe
+    gen c, t, typ
+    c.add ParRi
+    case c.m.types[t[typ].typeId].kind
+    of UIntTy:
+      let x = cast[uint64](c.m.lit.numbers[litId])
+      c.add $x
+    of FloatTy:
+      let x = cast[float64](c.m.lit.numbers[litId])
+      c.add $x
+    else:
+      gen c, t, arg
+    c.add ParRi
+  else:
+    binaryop ""
+
+template moveToDataSection(body: untyped) =
+  let oldLen = c.code.len
+  body
+  for i in oldLen ..< c.code.len:
+    c.data.add c.code[i]
+  setLen c.code, oldLen
+
+proc gen(c: var GeneratedCode; t: Tree; n: NodePos) =
+  case t[n].kind
+  of Nop:
+    discard "nothing to emit"
+  of ImmediateVal:
+    c.add $t[n].immediateVal
+  of IntVal:
+    genIntLit c, c.m.lit, t[n].litId
+  of StrVal:
+    c.code.add genStrLit(c, c.m.lit, t[n].litId)
+  of Typed:
+    genType c, c.m.types, c.m.lit, t[n].typeId
+  of SymDef, SymUse:
+    let s = t[n].symId
+    if c.needsPrefix.contains(s.int):
+      c.code.add mangleModuleName(c, c.m.namespace)
+      c.add "__"
+      c.add $s
+    else:
+      # XXX Use proper names here
+      c.add "q"
+      c.add $s
+
+  of ModuleSymUse:
+    let (x, y) = sons2(t, n)
+    let u = mangleModuleName(c, t[x].litId)
+    let s = t[y].immediateVal
+    c.code.add u
+    c.add "__"
+    c.add $s
+
+  of NilVal:
+    c.add NullPtr
+  of LoopLabel:
+    c.add WhileKeyword
+    c.add ParLe
+    c.add "1"
+    c.add ParRi
+    c.add CurlyLe
+  of GotoLoop:
+    c.add CurlyRi
+  of Label:
+    let lab = t[n].label
+    c.add "L"
+    c.add $lab.int
+    c.add Colon
+    c.add Semicolon
+  of Goto:
+    let lab = t[n].label
+    c.add "goto L"
+    c.add $lab.int
+    c.add Semicolon
+  of CheckedGoto:
+    discard "XXX todo"
+  of ArrayConstr:
+    c.add CurlyLe
+    c.add ".a = "
+    c.add CurlyLe
+    var i = 0
+    for ch in sonsFrom1(t, n):
+      if i > 0: c.add Comma
+      c.gen t, ch
+      inc i
+    c.add CurlyRi
+    c.add CurlyRi
+  of ObjConstr:
+    c.add CurlyLe
+    var i = 0
+    for ch in sonsFrom1(t, n):
+      if i mod 2 == 0:
+        if i > 0: c.add Comma
+        c.add ".F" & $t[ch].immediateVal
+        c.add AsgnOpr
+      else:
+        c.gen t, ch
+      inc i
+    c.add CurlyRi
+  of Ret:
+    c.add ReturnKeyword
+    c.gen t, n.firstSon
+    c.add Semicolon
+  of Select:
+    c.add SwitchKeyword
+    c.add ParLe
+    let (_, selector) = sons2(t, n)
+    c.gen t, selector
+    c.add ParRi
+    c.add CurlyLe
+    for ch in sonsFromN(t, n, 2):
+      c.gen t, ch
+    c.add CurlyRi
+  of SelectPair:
+    let (le, ri) = sons2(t, n)
+    c.gen t, le
+    c.gen t, ri
+  of SelectList:
+    for ch in sons(t, n):
+      c.gen t, ch
+  of SelectValue:
+    c.add CaseKeyword
+    c.gen t, n.firstSon
+    c.add Colon
+  of SelectRange:
+    let (le, ri) = sons2(t, n)
+    c.add CaseKeyword
+    c.gen t, le
+    c.add " ... "
+    c.gen t, ri
+    c.add Colon
+  of ForeignDecl:
+    c.data.add LitId(ExternKeyword)
+    c.gen t, n.firstSon
+  of SummonGlobal:
+    moveToDataSection:
+      let (typ, sym) = sons2(t, n)
+      c.genGlobal t, sym, typ, ""
+      c.add Semicolon
+  of SummonThreadLocal:
+    moveToDataSection:
+      let (typ, sym) = sons2(t, n)
+      c.genGlobal t, sym, typ, "__thread "
+      c.add Semicolon
+  of SummonConst:
+    moveToDataSection:
+      let (typ, sym, val) = sons3(t, n)
+      c.genGlobal t, sym, typ, "const "
+      c.add AsgnOpr
+      c.gen t, val
+      c.add Semicolon
+  of Summon, SummonResult:
+    let (typ, sym) = sons2(t, n)
+    c.genLocal t, sym, typ, ""
+    c.add Semicolon
+
+  of SummonParam:
+    raiseAssert "SummonParam should have been handled in genProc"
+  of Kill:
+    discard "we don't care about Kill instructions"
+  of AddrOf:
+    let (_, arg) = sons2(t, n)
+    c.add "&"
+    gen c, t, arg
+  of DerefArrayAt:
+    let (_, a, i) = sons3(t, n)
+    gen c, t, a
+    c.add BracketLe
+    gen c, t, i
+    c.add BracketRi
+  of ArrayAt:
+    let (_, a, i) = sons3(t, n)
+    gen c, t, a
+    c.add Dot
+    c.add "a"
+    c.add BracketLe
+    gen c, t, i
+    c.add BracketRi
+  of FieldAt:
+    let (_, a, b) = sons3(t, n)
+    gen c, t, a
+    let field = t[b].immediateVal
+    c.add Dot
+    c.add "F" & $field
+  of DerefFieldAt:
+    let (_, a, b) = sons3(t, n)
+    gen c, t, a
+    let field = t[b].immediateVal
+    c.add Arrow
+    c.add "F" & $field
+  of Load:
+    let (_, arg) = sons2(t, n)
+    c.add ParLe
+    c.add "*"
+    gen c, t, arg
+    c.add ParRi
+  of Store:
+    raiseAssert "Assumption was that Store is unused!"
+  of Asgn:
+    let (_, dest, src) = sons3(t, n)
+    gen c, t, dest
+    c.add AsgnOpr
+    gen c, t, src
+    c.add Semicolon
+  of CheckedRange:
+    c.add "nimCheckRange"
+    c.add ParLe
+    let (_, gotoInstr, x, a, b) = sons5(t, n)
+    gen c, t, x
+    c.add Comma
+    gen c, t, a
+    c.add Comma
+    gen c, t, b
+    c.add Comma
+    c.add "L" & $t[gotoInstr].label.int
+    c.add ParRi
+  of CheckedIndex:
+    c.add "nimCheckIndex"
+    c.add ParLe
+    let (gotoInstr, x, a) = sons3(t, n)
+    gen c, t, x
+    c.add Comma
+    gen c, t, a
+    c.add Comma
+    c.add "L" & $t[gotoInstr].label.int
+    c.add ParRi
+  of Call, IndirectCall:
+    let (typ, fn) = sons2(t, n)
+    gen c, t, fn
+    c.add ParLe
+    var i = 0
+    for ch in sonsFromN(t, n, 2):
+      if i > 0: c.add Comma
+      gen c, t, ch
+      inc i
+    c.add ParRi
+    if c.m.types[t[typ].typeId].kind == VoidTy:
+      c.add Semicolon
+  of CheckedCall, CheckedIndirectCall:
+    let (typ, gotoInstr, fn) = sons3(t, n)
+    gen c, t, fn
+    c.add ParLe
+    var i = 0
+    for ch in sonsFromN(t, n, 3):
+      if i > 0: c.add Comma
+      gen c, t, ch
+      inc i
+    c.add ParRi
+    if c.m.types[t[typ].typeId].kind == VoidTy:
+      c.add Semicolon
+
+  of CheckedAdd: checkedBinaryop "nimAddInt"
+  of CheckedSub: checkedBinaryop "nimSubInt"
+  of CheckedMul: checkedBinaryop "nimMulInt"
+  of CheckedDiv: checkedBinaryop "nimDivInt"
+  of CheckedMod: checkedBinaryop "nimModInt"
+  of Add: triop " + "
+  of Sub: triop " - "
+  of Mul: triop " * "
+  of Div: triop " / "
+  of Mod: triop " % "
+  of BitShl: triop " << "
+  of BitShr: triop " >> "
+  of BitAnd: triop " & "
+  of BitOr: triop " | "
+  of BitXor: triop " ^ "
+  of BitNot: binaryop " ~ "
+  of BoolNot: binaryop " !"
+  of Eq: cmpop " == "
+  of Le: cmpop " <= "
+  of Lt: cmpop " < "
+  of Cast: binaryop ""
+  of NumberConv: genNumberConv c, t, n
+  of CheckedObjConv: binaryop ""
+  of ObjConv: binaryop ""
+  of Emit: raiseAssert "cannot interpret: Emit"
+  of ProcDecl: genProcDecl c, t, n, false
+  of ForeignProcDecl: genProcDecl c, t, n, true
+  of PragmaPair, PragmaId, TestOf, Yld, SetExc, TestExc:
+    c.add "cannot interpret: " & $t[n].kind
+
+const
+  Prelude = """
+/* GENERATED CODE. DO NOT EDIT. */
+
+#ifdef __cplusplus
+#define NB8 bool
+#elif (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901)
+// see #13798: to avoid conflicts for code emitting `#include <stdbool.h>`
+#define NB8 _Bool
+#else
+typedef unsigned char NB8; // best effort
+#endif
+
+typedef unsigned char NC8;
+
+typedef float NF32;
+typedef double NF64;
+#if defined(__BORLANDC__) || defined(_MSC_VER)
+typedef signed char NI8;
+typedef signed short int NI16;
+typedef signed int NI32;
+typedef __int64 NI64;
+/* XXX: Float128? */
+typedef unsigned char NU8;
+typedef unsigned short int NU16;
+typedef unsigned int NU32;
+typedef unsigned __int64 NU64;
+#elif defined(HAVE_STDINT_H)
+#ifndef USE_NIM_NAMESPACE
+#  include <stdint.h>
+#endif
+typedef int8_t NI8;
+typedef int16_t NI16;
+typedef int32_t NI32;
+typedef int64_t NI64;
+typedef uint8_t NU8;
+typedef uint16_t NU16;
+typedef uint32_t NU32;
+typedef uint64_t NU64;
+#elif defined(HAVE_CSTDINT)
+#ifndef USE_NIM_NAMESPACE
+#  include <cstdint>
+#endif
+typedef std::int8_t NI8;
+typedef std::int16_t NI16;
+typedef std::int32_t NI32;
+typedef std::int64_t NI64;
+typedef std::uint8_t NU8;
+typedef std::uint16_t NU16;
+typedef std::uint32_t NU32;
+typedef std::uint64_t NU64;
+#else
+/* Unknown compiler/version, do our best */
+#ifdef __INT8_TYPE__
+typedef __INT8_TYPE__ NI8;
+#else
+typedef signed char NI8;
+#endif
+#ifdef __INT16_TYPE__
+typedef __INT16_TYPE__ NI16;
+#else
+typedef signed short int NI16;
+#endif
+#ifdef __INT32_TYPE__
+typedef __INT32_TYPE__ NI32;
+#else
+typedef signed int NI32;
+#endif
+#ifdef __INT64_TYPE__
+typedef __INT64_TYPE__ NI64;
+#else
+typedef long long int NI64;
+#endif
+/* XXX: Float128? */
+#ifdef __UINT8_TYPE__
+typedef __UINT8_TYPE__ NU8;
+#else
+typedef unsigned char NU8;
+#endif
+#ifdef __UINT16_TYPE__
+typedef __UINT16_TYPE__ NU16;
+#else
+typedef unsigned short int NU16;
+#endif
+#ifdef __UINT32_TYPE__
+typedef __UINT32_TYPE__ NU32;
+#else
+typedef unsigned int NU32;
+#endif
+#ifdef __UINT64_TYPE__
+typedef __UINT64_TYPE__ NU64;
+#else
+typedef unsigned long long int NU64;
+#endif
+#endif
+
+#ifdef NIM_INTBITS
+#  if NIM_INTBITS == 64
+typedef NI64 NI;
+typedef NU64 NU;
+#  elif NIM_INTBITS == 32
+typedef NI32 NI;
+typedef NU32 NU;
+#  elif NIM_INTBITS == 16
+typedef NI16 NI;
+typedef NU16 NU;
+#  elif NIM_INTBITS == 8
+typedef NI8 NI;
+typedef NU8 NU;
+#  else
+#    error "invalid bit width for int"
+#  endif
+#endif
+
+#define NIM_STRLIT_FLAG ((NU)(1) << ((NIM_INTBITS) - 2)) /* This has to be the same as system.strlitFlag! */
+
+#define nimAddInt64(a, b, L) ({long long int res; if(__builtin_saddll_overflow(a, b, &res)) goto L; res})
+#define nimSubInt64(a, b, L) ({long long int res; if(__builtin_ssubll_overflow(a, b, &res)) goto L; res})
+#define nimMulInt64(a, b, L) ({long long int res; if(__builtin_smulll_overflow(a, b, &res)) goto L; res})
+
+#define nimAddInt32(a, b, L) ({long int res; if(__builtin_sadd_overflow(a, b, &res)) goto L; res})
+#define nimSubInt32(a, b, L) ({long int res; if(__builtin_ssub_overflow(a, b, &res)) goto L; res})
+#define nimMulInt32(a, b, L) ({long int res; if(__builtin_smul_overflow(a, b, &res)) goto L; res})
+
+#define nimCheckRange(x, a, b, L) ({if (x < a || x > b) goto L; x})
+#define nimCheckIndex(x, a, L) ({if (x >= a) goto L; x})
+
+"""
+
+proc traverseCode(c: var GeneratedCode) =
+  const AllowedInToplevelC = {SummonConst, SummonGlobal, SummonThreadLocal,
+                              ProcDecl, ForeignDecl, ForeignProcDecl}
+  var i = NodePos(0)
+  while i.int < c.m.code.len:
+    let oldLen = c.code.len
+    let moveToInitSection = c.m.code[NodePos(i)].kind notin AllowedInToplevelC
+
+    gen c, c.m.code, NodePos(i)
+    next c.m.code, i
+
+    if moveToInitSection:
+      for i in oldLen ..< c.code.len:
+        c.init.add c.code[i]
+      setLen c.code, oldLen
+
+proc generateCode*(inp, outp: string) =
+  var c = initGeneratedCode(load(inp))
+
+  var co = TypeOrder()
+  traverseTypes(c.m.types, c.m.lit, co)
+
+  generateTypes(c, c.m.types, c.m.lit, co)
+  let typeDecls = move c.code
+
+  traverseCode c
+  var f = CppFile(f: open(outp, fmWrite))
+  f.write "#define NIM_INTBITS " & $c.m.intbits & "\n"
+  f.write Prelude
+  writeTokenSeq f, c.includes, c
+  writeTokenSeq f, typeDecls, c
+  writeTokenSeq f, c.data, c
+  writeTokenSeq f, c.protos, c
+  writeTokenSeq f, c.code, c
+  if c.init.len > 0:
+    f.write "void __attribute__((constructor)) init(void) {"
+    writeTokenSeq f, c.init, c
+    f.write "}\n\n"
+  f.f.close
--- a/compiler/nir/nir.nim
+++ b/compiler/nir/nir.nim
@@ -0,0 +1,105 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Nim Intermediate Representation, designed to capture all of Nim's semantics without losing too much
+## precious information. Can easily be translated into C. And to JavaScript, hopefully.
+
+from std/os import addFileExt, `/`, createDir
+
+import std / assertions
+import ".." / [ast, modulegraphs, renderer, transf, options, msgs, lineinfos]
+import nirtypes, nirinsts, ast2ir, nirlineinfos, nirfiles, nirvm
+
+import ".." / ic / [rodfiles, bitabs]
+
+type
+  PCtx* = ref object of TPassContext
+    m: ModuleCon
+    c: ProcCon
+    oldErrorCount: int
+    bytecode: Bytecode
+
+proc newCtx*(module: PSym; g: ModuleGraph; idgen: IdGenerator): PCtx =
+  var lit = Literals()
+  var nirm = (ref NirModule)(types: initTypeGraph(lit), lit: lit)
+  var m = initModuleCon(g, g.config, idgen, module, nirm)
+  m.noModularity = true
+  PCtx(m: m, c: initProcCon(m, nil, g.config), idgen: idgen, bytecode: initBytecode(nirm))
+
+proc refresh*(c: PCtx; module: PSym; idgen: IdGenerator) =
+  #c.m = initModuleCon(c.m.graph, c.m.graph.config, idgen, module, c.m.nirm)
+  #c.m.noModularity = true
+  c.c = initProcCon(c.m, nil, c.m.graph.config)
+  c.idgen = idgen
+
+proc setupGlobalCtx*(module: PSym; graph: ModuleGraph; idgen: IdGenerator) =
+  if graph.repl.isNil:
+    graph.repl = newCtx(module, graph, idgen)
+    #registerAdditionalOps(PCtx graph.repl)
+  else:
+    refresh(PCtx graph.repl, module, idgen)
+
+proc setupNirReplGen*(graph: ModuleGraph; module: PSym; idgen: IdGenerator): PPassContext =
+  setupGlobalCtx(module, graph, idgen)
+  result = PCtx graph.repl
+
+proc evalStmt(c: PCtx; n: PNode) =
+  let n = transformExpr(c.m.graph, c.idgen, c.m.module, n)
+  let pc = genStmt(c.c, n)
+  #var res = ""
+  #toString c.m.nirm.code, NodePos(pc), c.m.nirm.lit.strings, c.m.nirm.lit.numbers, c.m.symnames, res
+  #res.add "\n--------------------------\n"
+  #toString res, c.m.types.g
+  if pc.int < c.m.nirm.code.len:
+    c.bytecode.interactive = c.m.graph.interactive
+    execCode c.bytecode, c.m.nirm.code, pc
+  #echo res
+
+proc runCode*(c: PPassContext; n: PNode): PNode =
+  let c = PCtx(c)
+  # don't eval errornous code:
+  if c.oldErrorCount == c.m.graph.config.errorCounter:
+    evalStmt(c, n)
+    result = newNodeI(nkEmpty, n.info)
+  else:
+    result = n
+  c.oldErrorCount = c.m.graph.config.errorCounter
+
+type
+  NirPassContext* = ref object of TPassContext
+    m: ModuleCon
+    c: ProcCon
+
+proc openNirBackend*(g: ModuleGraph; module: PSym; idgen: IdGenerator): PPassContext =
+  var lit = Literals()
+  var nirm = (ref NirModule)(types: initTypeGraph(lit), lit: lit)
+  let m = initModuleCon(g, g.config, idgen, module, nirm)
+  NirPassContext(m: m, c: initProcCon(m, nil, g.config), idgen: idgen)
+
+proc gen(c: NirPassContext; n: PNode) =
+  let n = transformExpr(c.m.graph, c.idgen, c.m.module, n)
+  let pc = genStmt(c.c, n)
+
+proc nirBackend*(c: PPassContext; n: PNode): PNode =
+  gen(NirPassContext(c), n)
+  result = n
+
+proc closeNirBackend*(c: PPassContext; finalNode: PNode) =
+  discard nirBackend(c, finalNode)
+
+  let c = NirPassContext(c)
+  let nimcache = getNimcacheDir(c.c.config).string
+  createDir nimcache
+  let outp = nimcache / c.m.module.name.s.addFileExt("nir")
+  #c.m.nirm.code = move c.c.code
+  try:
+    store c.m.nirm[], outp
+    echo "created: ", outp
+  except IOError:
+    rawMessage(c.c.config, errFatal, "serialization failed: " & outp)
--- a/compiler/nir/nirc.nim
+++ b/compiler/nir/nirc.nim
@@ -0,0 +1,52 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Nir Compiler.
+
+import ".." / ic / [bitabs, rodfiles]
+import nirinsts, nirtypes, nirlineinfos, nirfiles, cir
+
+proc view(filename: string) =
+  let m = load(filename)
+  var res = ""
+  allTreesToString m.code, m.lit.strings, m.lit.numbers, m.symnames, res
+  res.add "\n# TYPES\n"
+  nirtypes.toString res, m.types
+  echo res
+
+import std / [syncio, parseopt]
+
+proc writeHelp =
+  echo """Usage: nirc view|c <file.nir>"""
+  quit 0
+
+proc main =
+  var inp = ""
+  var cmd = ""
+  for kind, key, val in getopt():
+    case kind
+    of cmdArgument:
+      if cmd.len == 0: cmd = key
+      elif inp.len == 0: inp = key
+      else: quit "Error: too many arguments"
+    of cmdLongOption, cmdShortOption:
+      case key
+      of "help", "h": writeHelp()
+      of "version", "v": stdout.write "1.0\n"
+    of cmdEnd: discard
+  if inp.len == 0:
+    quit "Error: no input file specified"
+  case cmd
+  of "", "view":
+    view inp
+  of "c":
+    let outp = inp & ".c"
+    cir.generateCode inp, outp
+
+main()
--- a/compiler/nir/nirfiles.nim
+++ b/compiler/nir/nirfiles.nim
@@ -0,0 +1,83 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+import ".." / ic / [bitabs, rodfiles]
+import nirinsts, nirtypes, nirlineinfos
+
+type
+  NirModule* = object
+    code*: Tree
+    man*: LineInfoManager
+    types*: TypeGraph
+    lit*: Literals
+    namespace*: LitId
+    intbits*: uint32
+    symnames*: SymNames
+
+proc load*(filename: string): NirModule =
+  let lit = Literals()
+  result = NirModule(lit: lit, types: initTypeGraph(lit))
+  var r = rodfiles.open(filename)
+  try:
+    r.loadHeader(nirCookie)
+    r.loadSection stringsSection
+    r.load result.lit.strings
+
+    r.loadSection numbersSection
+    r.load result.lit.numbers
+
+    r.loadSection bodiesSection
+    r.load result.code
+
+    r.loadSection typesSection
+    r.load result.types
+
+    r.loadSection sideChannelSection
+    r.load result.man
+
+    r.loadSection namespaceSection
+    r.loadPrim result.namespace
+    r.loadPrim result.intbits
+
+    r.loadSection symnamesSection
+    r.load result.symnames
+
+  finally:
+    r.close()
+
+proc store*(m: NirModule; outp: string) =
+  var r = rodfiles.create(outp)
+  try:
+    r.storeHeader(nirCookie)
+    r.storeSection stringsSection
+    r.store m.lit.strings
+
+    r.storeSection numbersSection
+    r.store m.lit.numbers
+
+    r.storeSection bodiesSection
+    r.store m.code
+
+    r.storeSection typesSection
+    r.store m.types
+
+    r.storeSection sideChannelSection
+    r.store m.man
+
+    r.storeSection namespaceSection
+    r.storePrim m.namespace
+    r.storePrim m.intbits
+
+    r.storeSection symnamesSection
+    r.store m.symnames
+
+  finally:
+    r.close()
+  if r.err != ok:
+    raise newException(IOError, "could store into: " & outp)
--- a/compiler/nir/nirinsts.nim
+++ b/compiler/nir/nirinsts.nim
@@ -0,0 +1,582 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## NIR instructions. Somewhat inspired by LLVM's instructions.
+
+import std / [assertions, hashes]
+import .. / ic / [bitabs, rodfiles]
+import nirlineinfos, nirtypes
+
+const
+  NirVersion = 1
+  nirCookie* = [byte(0), byte('N'), byte('I'), byte('R'),
+            byte(sizeof(int)*8), byte(system.cpuEndian), byte(0), byte(NirVersion)]
+
+type
+  SymId* = distinct int
+
+proc `$`*(s: SymId): string {.borrow.}
+proc hash*(s: SymId): Hash {.borrow.}
+proc `==`*(a, b: SymId): bool {.borrow.}
+
+type
+  Opcode* = enum
+    Nop,
+    ImmediateVal,
+    IntVal,
+    StrVal,
+    SymDef,
+    SymUse,
+    Typed,   # with type ID
+    PragmaId, # with Pragma ID, possible values: see PragmaKey enum
+    NilVal,
+    Label,
+    Goto,
+    CheckedGoto,
+    LoopLabel,
+    GotoLoop,  # last atom
+
+    ModuleSymUse, # `"module".x`
+
+    ArrayConstr,
+    ObjConstr,
+    Ret,
+    Yld,
+
+    Select,
+    SelectPair,  # ((values...), Label)
+    SelectList,  # (values...)
+    SelectValue, # (value)
+    SelectRange, # (valueA..valueB)
+    ForeignDecl, # Can wrap SummonGlobal, SummonThreadLocal, SummonConst
+    SummonGlobal,
+    SummonThreadLocal,
+    Summon, # x = Summon Typed <Type ID>; x begins to live
+    SummonResult,
+    SummonParam,
+    SummonConst,
+    Kill, # `Kill x`: scope end for `x`
+
+    AddrOf,
+    ArrayAt, # a[i]
+    DerefArrayAt, # a[i] where `a` is a PtrArray; `a[][i]`
+    FieldAt, # obj.field
+    DerefFieldAt, # obj[].field
+
+    Load, # a[]
+    Store, # a[] = b
+    Asgn,  # a = b
+    SetExc,
+    TestExc,
+
+    CheckedRange,
+    CheckedIndex,
+
+    Call,
+    IndirectCall,
+    CheckedCall, # call that can raise
+    CheckedIndirectCall, # call that can raise
+    CheckedAdd, # with overflow checking etc.
+    CheckedSub,
+    CheckedMul,
+    CheckedDiv,
+    CheckedMod,
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod,
+    BitShl,
+    BitShr,
+    BitAnd,
+    BitOr,
+    BitXor,
+    BitNot,
+    BoolNot,
+    Eq,
+    Le,
+    Lt,
+    Cast,
+    NumberConv,
+    CheckedObjConv,
+    ObjConv,
+    TestOf,
+    Emit,
+    ProcDecl,
+    ForeignProcDecl,
+    PragmaPair
+
+type
+  PragmaKey* = enum
+    FastCall, StdCall, CDeclCall, SafeCall, SysCall, InlineCall, NoinlineCall, ThisCall, NoCall,
+    CoreName,
+    ExternName,
+    HeaderImport,
+    DllImport,
+    DllExport,
+    ObjExport
+
+const
+  LastAtomicValue = GotoLoop
+
+  OpcodeBits = 8'u32
+  OpcodeMask = (1'u32 shl OpcodeBits) - 1'u32
+
+  ValueProducingAtoms = {ImmediateVal, IntVal, StrVal, SymUse, NilVal}
+
+  ValueProducing* = {
+    ImmediateVal,
+    IntVal,
+    StrVal,
+    SymUse,
+    NilVal,
+    ModuleSymUse,
+    ArrayConstr,
+    ObjConstr,
+    CheckedAdd,
+    CheckedSub,
+    CheckedMul,
+    CheckedDiv,
+    CheckedMod,
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod,
+    BitShl,
+    BitShr,
+    BitAnd,
+    BitOr,
+    BitXor,
+    BitNot,
+    BoolNot,
+    Eq,
+    Le,
+    Lt,
+    Cast,
+    NumberConv,
+    CheckedObjConv,
+    ObjConv,
+    AddrOf,
+    Load,
+    ArrayAt,
+    DerefArrayAt,
+    FieldAt,
+    DerefFieldAt,
+    TestOf
+  }
+
+type
+  Instr* = object     # 8 bytes
+    x: uint32
+    info*: PackedLineInfo
+
+template kind*(n: Instr): Opcode = Opcode(n.x and OpcodeMask)
+template operand(n: Instr): uint32 = (n.x shr OpcodeBits)
+
+template rawOperand*(n: Instr): uint32 = (n.x shr OpcodeBits)
+
+template toX(k: Opcode; operand: uint32): uint32 =
+  uint32(k) or (operand shl OpcodeBits)
+
+template toX(k: Opcode; operand: LitId): uint32 =
+  uint32(k) or (operand.uint32 shl OpcodeBits)
+
+type
+  Tree* = object
+    nodes: seq[Instr]
+
+  Values* = object
+    numbers: BiTable[int64]
+    strings: BiTable[string]
+
+type
+  PatchPos* = distinct int
+  NodePos* = distinct int
+
+const
+  InvalidPatchPos* = PatchPos(-1)
+
+proc isValid(p: PatchPos): bool {.inline.} = p.int != -1
+
+proc prepare*(tree: var Tree; info: PackedLineInfo; kind: Opcode): PatchPos =
+  result = PatchPos tree.nodes.len
+  tree.nodes.add Instr(x: toX(kind, 1'u32), info: info)
+
+proc isAtom(tree: Tree; pos: int): bool {.inline.} = tree.nodes[pos].kind <= LastAtomicValue
+proc isAtom(tree: Tree; pos: NodePos): bool {.inline.} = tree.nodes[pos.int].kind <= LastAtomicValue
+
+proc patch*(tree: var Tree; pos: PatchPos) =
+  let pos = pos.int
+  let k = tree.nodes[pos].kind
+  assert k > LastAtomicValue
+  let distance = int32(tree.nodes.len - pos)
+  assert distance > 0
+  tree.nodes[pos].x = toX(k, cast[uint32](distance))
+
+template build*(tree: var Tree; info: PackedLineInfo; kind: Opcode; body: untyped) =
+  let pos = prepare(tree, info, kind)
+  body
+  patch(tree, pos)
+
+template buildTyped*(tree: var Tree; info: PackedLineInfo; kind: Opcode; typ: TypeId; body: untyped) =
+  let pos = prepare(tree, info, kind)
+  tree.addTyped info, typ
+  body
+  patch(tree, pos)
+
+proc len*(tree: Tree): int {.inline.} = tree.nodes.len
+
+template rawSpan(n: Instr): int = int(operand(n))
+
+proc nextChild(tree: Tree; pos: var int) {.inline.} =
+  if tree.nodes[pos].kind > LastAtomicValue:
+    assert tree.nodes[pos].operand > 0'u32
+    inc pos, tree.nodes[pos].rawSpan
+  else:
+    inc pos
+
+proc next*(tree: Tree; pos: var NodePos) {.inline.} = nextChild tree, int(pos)
+
+template firstSon*(n: NodePos): NodePos = NodePos(n.int+1)
+
+template skipTyped*(n: NodePos): NodePos = NodePos(n.int+2)
+
+iterator sons*(tree: Tree; n: NodePos): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+iterator sonsFrom1*(tree: Tree; n: NodePos): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  nextChild tree, pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+iterator sonsFromN*(tree: Tree; n: NodePos; toSkip = 2): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  for i in 1..toSkip:
+    nextChild tree, pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+template `[]`*(t: Tree; n: NodePos): Instr = t.nodes[n.int]
+
+iterator sonsRest*(tree: Tree; parent, n: NodePos): NodePos =
+  var pos = n.int
+  assert tree[parent].kind > LastAtomicValue
+  let last = parent.int + tree[parent].rawSpan
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+proc span(tree: Tree; pos: int): int {.inline.} =
+  if tree.nodes[pos].kind <= LastAtomicValue: 1 else: int(tree.nodes[pos].operand)
+
+proc copyTree*(dest: var Tree; src: Tree) =
+  let pos = 0
+  let L = span(src, pos)
+  let d = dest.nodes.len
+  dest.nodes.setLen(d + L)
+  assert L > 0
+  for i in 0..<L:
+    dest.nodes[d+i] = src.nodes[pos+i]
+
+proc sons2*(tree: Tree; n: NodePos): (NodePos, NodePos) {.inline.} =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  result = (NodePos a, NodePos b)
+
+proc sons3*(tree: Tree; n: NodePos): (NodePos, NodePos, NodePos) {.inline.} =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  result = (NodePos a, NodePos b, NodePos c)
+
+proc sons4*(tree: Tree; n: NodePos): (NodePos, NodePos, NodePos, NodePos) {.inline.} =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  let d = c + span(tree, c)
+  result = (NodePos a, NodePos b, NodePos c, NodePos d)
+
+proc sons5*(tree: Tree; n: NodePos): (NodePos, NodePos, NodePos, NodePos, NodePos) {.inline.} =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  let d = c + span(tree, c)
+  let e = d + span(tree, d)
+  result = (NodePos a, NodePos b, NodePos c, NodePos d, NodePos e)
+
+proc typeId*(ins: Instr): TypeId {.inline.} =
+  assert ins.kind == Typed
+  result = TypeId(ins.operand)
+
+proc symId*(ins: Instr): SymId {.inline.} =
+  assert ins.kind in {SymUse, SymDef}
+  result = SymId(ins.operand)
+
+proc immediateVal*(ins: Instr): int {.inline.} =
+  assert ins.kind == ImmediateVal
+  result = cast[int](ins.operand)
+
+proc litId*(ins: Instr): LitId {.inline.} =
+  assert ins.kind in {StrVal, IntVal}
+  result = LitId(ins.operand)
+
+
+type
+  LabelId* = distinct int
+
+proc `==`*(a, b: LabelId): bool {.borrow.}
+proc hash*(a: LabelId): Hash {.borrow.}
+
+proc label*(ins: Instr): LabelId {.inline.} =
+  assert ins.kind in {Label, LoopLabel, Goto, GotoLoop, CheckedGoto}
+  result = LabelId(ins.operand)
+
+proc newLabel*(labelGen: var int): LabelId {.inline.} =
+  result = LabelId labelGen
+  inc labelGen
+
+proc newLabels*(labelGen: var int; n: int): LabelId {.inline.} =
+  result = LabelId labelGen
+  inc labelGen, n
+
+proc addNewLabel*(t: var Tree; labelGen: var int; info: PackedLineInfo; k: Opcode): LabelId =
+  assert k in {Label, LoopLabel}
+  result = LabelId labelGen
+  t.nodes.add Instr(x: toX(k, uint32(result)), info: info)
+  inc labelGen
+
+proc gotoLabel*(t: var Tree; info: PackedLineInfo; k: Opcode; L: LabelId) =
+  assert k in {Goto, GotoLoop, CheckedGoto}
+  t.nodes.add Instr(x: toX(k, uint32(L)), info: info)
+
+proc addLabel*(t: var Tree; info: PackedLineInfo; k: Opcode; L: LabelId) {.inline.} =
+  assert k in {Label, LoopLabel, Goto, GotoLoop, CheckedGoto}
+  t.nodes.add Instr(x: toX(k, uint32(L)), info: info)
+
+proc addSymUse*(t: var Tree; info: PackedLineInfo; s: SymId) {.inline.} =
+  t.nodes.add Instr(x: toX(SymUse, uint32(s)), info: info)
+
+proc addSymDef*(t: var Tree; info: PackedLineInfo; s: SymId) {.inline.} =
+  t.nodes.add Instr(x: toX(SymDef, uint32(s)), info: info)
+
+proc addNop*(t: var Tree; info: PackedLineInfo) {.inline.} =
+  t.nodes.add Instr(x: toX(Nop, 0'u32), info: info)
+
+proc addTyped*(t: var Tree; info: PackedLineInfo; typ: TypeId) {.inline.} =
+  assert typ.int >= 0
+  t.nodes.add Instr(x: toX(Typed, uint32(typ)), info: info)
+
+proc addSummon*(t: var Tree; info: PackedLineInfo; s: SymId; typ: TypeId; opc = Summon) {.inline.} =
+  assert typ.int >= 0
+  assert opc in {Summon, SummonConst, SummonGlobal, SummonThreadLocal, SummonParam, SummonResult}
+  let x = prepare(t, info, opc)
+  t.nodes.add Instr(x: toX(Typed, uint32(typ)), info: info)
+  t.nodes.add Instr(x: toX(SymDef, uint32(s)), info: info)
+  patch t, x
+
+proc addImmediateVal*(t: var Tree; info: PackedLineInfo; x: int) =
+  assert x >= 0 and x < ((1 shl 32) - OpcodeBits.int)
+  t.nodes.add Instr(x: toX(ImmediateVal, uint32(x)), info: info)
+
+proc addPragmaId*(t: var Tree; info: PackedLineInfo; x: PragmaKey) =
+  t.nodes.add Instr(x: toX(PragmaId, uint32(x)), info: info)
+
+proc addIntVal*(t: var Tree; integers: var BiTable[int64]; info: PackedLineInfo; typ: TypeId; x: int64) =
+  buildTyped t, info, NumberConv, typ:
+    t.nodes.add Instr(x: toX(IntVal, uint32(integers.getOrIncl(x))), info: info)
+
+proc boolVal*(t: var Tree; integers: var BiTable[int64]; info: PackedLineInfo; b: bool) =
+  buildTyped t, info, NumberConv, Bool8Id:
+    t.nodes.add Instr(x: toX(IntVal, uint32(integers.getOrIncl(ord b))), info: info)
+
+proc addStrVal*(t: var Tree; strings: var BiTable[string]; info: PackedLineInfo; s: string) =
+  t.nodes.add Instr(x: toX(StrVal, uint32(strings.getOrIncl(s))), info: info)
+
+proc addStrLit*(t: var Tree; info: PackedLineInfo; s: LitId) =
+  t.nodes.add Instr(x: toX(StrVal, uint32(s)), info: info)
+
+proc addNilVal*(t: var Tree; info: PackedLineInfo; typ: TypeId) =
+  buildTyped t, info, NumberConv, typ:
+    t.nodes.add Instr(x: toX(NilVal, uint32(0)), info: info)
+
+proc store*(r: var RodFile; t: Tree) = storeSeq r, t.nodes
+proc load*(r: var RodFile; t: var Tree) = loadSeq r, t.nodes
+
+proc escapeToNimLit*(s: string; result: var string) =
+  result.add '"'
+  for c in items s:
+    if c < ' ' or int(c) >= 128:
+      result.add '\\'
+      result.addInt int(c)
+    elif c == '\\':
+      result.add r"\\"
+    elif c == '\n':
+      result.add r"\n"
+    elif c == '\r':
+      result.add r"\r"
+    elif c == '\t':
+      result.add r"\t"
+    else:
+      result.add c
+  result.add '"'
+
+type
+  SymNames* = object
+    s: seq[LitId]
+
+proc `[]=`*(t: var SymNames; key: SymId; val: LitId) =
+  let k = int(key)
+  if k >= t.s.len: t.s.setLen k+1
+  t.s[k] = val
+
+proc `[]`*(t: SymNames; key: SymId): LitId =
+  let k = int(key)
+  if k < t.s.len: result = t.s[k]
+  else: result = LitId(0)
+
+template localName(s: SymId): string =
+  let name = names[s]
+  if name != LitId(0):
+    strings[name]
+  else:
+    $s.int
+
+proc store*(r: var RodFile; t: SymNames) = storeSeq(r, t.s)
+proc load*(r: var RodFile; t: var SymNames) = loadSeq(r, t.s)
+
+proc toString*(t: Tree; pos: NodePos; strings: BiTable[string]; integers: BiTable[int64];
+               names: SymNames;
+               r: var string; nesting = 0) =
+  if r.len > 0 and r[r.len-1] notin {' ', '\n', '(', '[', '{'}:
+    r.add ' '
+
+  case t[pos].kind
+  of Nop: r.add "Nop"
+  of ImmediateVal:
+    r.add $t[pos].operand
+  of IntVal:
+    r.add "IntVal "
+    r.add $integers[LitId t[pos].operand]
+  of StrVal:
+    escapeToNimLit(strings[LitId t[pos].operand], r)
+  of SymDef:
+    r.add "SymDef "
+    r.add localName(SymId t[pos].operand)
+  of SymUse:
+    r.add "SymUse "
+    r.add localName(SymId t[pos].operand)
+  of PragmaId:
+    r.add $cast[PragmaKey](t[pos].operand)
+  of Typed:
+    r.add "T<"
+    r.add $t[pos].operand
+    r.add ">"
+  of NilVal:
+    r.add "NilVal"
+  of Label:
+    # undo the nesting:
+    var spaces = r.len-1
+    while spaces >= 0 and r[spaces] == ' ': dec spaces
+    r.setLen spaces+1
+    r.add "\n  L"
+    r.add $t[pos].operand
+  of Goto, CheckedGoto, LoopLabel, GotoLoop:
+    r.add $t[pos].kind
+    r.add " L"
+    r.add $t[pos].operand
+  else:
+    r.add $t[pos].kind
+    r.add "{\n"
+    for i in 0..<(nesting+1)*2: r.add ' '
+    for p in sons(t, pos):
+      toString t, p, strings, integers, names, r, nesting+1
+    r.add "\n"
+    for i in 0..<nesting*2: r.add ' '
+    r.add "}"
+
+proc allTreesToString*(t: Tree; strings: BiTable[string]; integers: BiTable[int64];
+                       names: SymNames;
+                       r: var string) =
+  var i = 0
+  while i < t.len:
+    toString t, NodePos(i), strings, integers, names, r
+    nextChild t, i
+
+type
+  Value* = distinct Tree
+
+proc prepare*(dest: var Value; info: PackedLineInfo; k: Opcode): PatchPos {.inline.} =
+  assert k in ValueProducing - ValueProducingAtoms
+  result = prepare(Tree(dest), info, k)
+
+proc patch*(dest: var Value; pos: PatchPos) {.inline.} =
+  patch(Tree(dest), pos)
+
+proc localToValue*(info: PackedLineInfo; s: SymId): Value =
+  result = Value(Tree())
+  Tree(result).addSymUse info, s
+
+proc hasValue*(v: Value): bool {.inline.} = Tree(v).len > 0
+
+proc isEmpty*(v: Value): bool {.inline.} = Tree(v).len == 0
+
+proc extractTemp*(v: Value): SymId =
+  if hasValue(v) and Tree(v)[NodePos 0].kind == SymUse:
+    result = SymId(Tree(v)[NodePos 0].operand)
+  else:
+    result = SymId(-1)
+
+proc copyTree*(dest: var Tree; src: Value) = copyTree dest, Tree(src)
+
+proc addImmediateVal*(t: var Value; info: PackedLineInfo; x: int) =
+  assert x >= 0 and x < ((1 shl 32) - OpcodeBits.int)
+  Tree(t).nodes.add Instr(x: toX(ImmediateVal, uint32(x)), info: info)
+
+template build*(tree: var Value; info: PackedLineInfo; kind: Opcode; body: untyped) =
+  let pos = prepare(Tree(tree), info, kind)
+  body
+  patch(tree, pos)
+
+proc addTyped*(t: var Value; info: PackedLineInfo; typ: TypeId) {.inline.} =
+  addTyped(Tree(t), info, typ)
+
+template buildTyped*(tree: var Value; info: PackedLineInfo; kind: Opcode; typ: TypeId; body: untyped) =
+  let pos = prepare(tree, info, kind)
+  tree.addTyped info, typ
+  body
+  patch(tree, pos)
+
+proc addStrVal*(t: var Value; strings: var BiTable[string]; info: PackedLineInfo; s: string) =
+  addStrVal(Tree(t), strings, info, s)
+
+proc addNilVal*(t: var Value; info: PackedLineInfo; typ: TypeId) =
+  addNilVal Tree(t), info, typ
+
+proc addIntVal*(t: var Value; integers: var BiTable[int64]; info: PackedLineInfo; typ: TypeId; x: int64) =
+  addIntVal Tree(t), integers, info, typ, x
--- a/compiler/nir/nirlineinfos.nim
+++ b/compiler/nir/nirlineinfos.nim
@@ -1,7 +1,7 @@
 #
 #
 #           The Nim Compiler
-#        (c) Copyright 2024 Andreas Rumpf
+#        (c) Copyright 2023 Andreas Rumpf
 #
 #    See the file "copying.txt", included in this
 #    distribution, for details about the copyright.
--- a/compiler/nir/nirslots.nim
+++ b/compiler/nir/nirslots.nim
@@ -0,0 +1,104 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Management of slots. Similar to "register allocation"
+## in lower level languages.
+
+import std / [assertions, tables]
+import nirtypes, nirinsts
+
+type
+  SlotManagerFlag* = enum
+    ReuseTemps,
+    ReuseVars
+  SlotKind* = enum
+    Temp, Perm
+  SlotManager* = object # "register allocator"
+    live: Table[SymId, (SlotKind, TypeId)]
+    dead: Table[TypeId, seq[SymId]]
+    flags: set[SlotManagerFlag]
+    inScope: seq[SymId]
+
+proc initSlotManager*(flags: set[SlotManagerFlag]): SlotManager {.inline.} =
+  SlotManager(flags: flags)
+
+proc allocRaw(m: var SlotManager; t: TypeId; f: SlotManagerFlag; k: SlotKind;
+              symIdgen: var int32): SymId {.inline.} =
+  if f in m.flags and m.dead.hasKey(t) and m.dead[t].len > 0:
+    result = m.dead[t].pop()
+  else:
+    inc symIdgen
+    result = SymId(symIdgen)
+    m.inScope.add result
+  m.live[result] = (k, t)
+
+proc allocTemp*(m: var SlotManager; t: TypeId; symIdgen: var int32): SymId {.inline.} =
+  result = allocRaw(m, t, ReuseTemps, Temp, symIdgen)
+
+proc allocVar*(m: var SlotManager; t: TypeId; symIdgen: var int32): SymId {.inline.} =
+  result = allocRaw(m, t, ReuseVars, Perm, symIdgen)
+
+proc freeLoc*(m: var SlotManager; s: SymId) =
+  let t = m.live.getOrDefault(s)
+  assert t[1].int != 0
+  m.live.del s
+  m.dead.mgetOrPut(t[1], @[]).add s
+
+proc freeTemp*(m: var SlotManager; s: SymId) =
+  let t = m.live.getOrDefault(s)
+  if t[1].int != 0 and t[0] == Temp:
+    m.live.del s
+    m.dead.mgetOrPut(t[1], @[]).add s
+
+iterator stillAlive*(m: SlotManager): (SymId, TypeId) =
+  for k, v in pairs(m.live):
+    yield (k, v[1])
+
+proc getType*(m: SlotManager; s: SymId): TypeId {.inline.} = m.live[s][1]
+
+proc openScope*(m: var SlotManager) =
+  m.inScope.add SymId(-1) # add marker
+
+proc closeScope*(m: var SlotManager) =
+  var i = m.inScope.len - 1
+  while i >= 0:
+    if m.inScope[i] == SymId(-1):
+      m.inScope.setLen i
+      break
+    dec i
+
+when isMainModule:
+  var symIdgen: int32
+  var m = initSlotManager({ReuseTemps})
+
+  var g = initTypeGraph(Literals())
+
+  let a = g.openType ArrayTy
+  g.addBuiltinType Int8Id
+  g.addArrayLen 5
+  let finalArrayType = finishType(g, a)
+
+  let obj = g.openType ObjectDecl
+  g.addName "MyType"
+
+  g.addField "p", finalArrayType, 0
+  let objB = finishType(g, obj)
+
+  let x = m.allocTemp(objB, symIdgen)
+  assert x.int == 0
+
+  let y = m.allocTemp(objB, symIdgen)
+  assert y.int == 1
+
+  let z = m.allocTemp(Int8Id, symIdgen)
+  assert z.int == 2
+
+  m.freeLoc y
+  let y2 = m.allocTemp(objB, symIdgen)
+  assert y2.int == 1
--- a/compiler/nir/nirtypes.nim
+++ b/compiler/nir/nirtypes.nim
@@ -0,0 +1,475 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Type system for NIR. Close to C's type system but without its quirks.
+
+import std / [assertions, hashes]
+import .. / ic / [bitabs, rodfiles]
+
+type
+  NirTypeKind* = enum
+    VoidTy, IntTy, UIntTy, FloatTy, BoolTy, CharTy, NameVal,
+    IntVal, SizeVal, AlignVal, OffsetVal,
+    AnnotationVal,
+    ObjectTy,
+    UnionTy,
+    VarargsTy, # the `...` in a C prototype; also the last "atom"
+    APtrTy, # pointer to aliasable memory
+    UPtrTy, # pointer to unique/unaliasable memory
+    AArrayPtrTy, # pointer to array of aliasable memory
+    UArrayPtrTy, # pointer to array of unique/unaliasable memory
+    ArrayTy,
+    LastArrayTy, # array of unspecified size as a last field inside an object
+    ProcTy,
+    ObjectDecl,
+    UnionDecl,
+    FieldDecl
+
+const
+  TypeKindBits = 8'u32
+  TypeKindMask = (1'u32 shl TypeKindBits) - 1'u32
+
+type
+  TypeNode* = object     # 4 bytes
+    x: uint32
+
+template kind*(n: TypeNode): NirTypeKind = NirTypeKind(n.x and TypeKindMask)
+template operand(n: TypeNode): uint32 = (n.x shr TypeKindBits)
+
+proc integralBits*(n: TypeNode): int {.inline.} =
+  # Number of bits in the IntTy, etc. Only valid for integral types.
+  assert n.kind in {IntTy, UIntTy, FloatTy, BoolTy, CharTy}
+  result = int(n.operand)
+
+template toX(k: NirTypeKind; operand: uint32): uint32 =
+  uint32(k) or (operand shl TypeKindBits)
+
+template toX(k: NirTypeKind; operand: LitId): uint32 =
+  uint32(k) or (operand.uint32 shl TypeKindBits)
+
+type
+  TypeId* = distinct int
+
+proc `==`*(a, b: TypeId): bool {.borrow.}
+proc hash*(a: TypeId): Hash {.borrow.}
+
+type
+  Literals* = ref object
+    strings*: BiTable[string]
+    numbers*: BiTable[int64]
+
+  TypeGraph* = object
+    nodes: seq[TypeNode]
+    lit: Literals
+
+const
+  VoidId* = TypeId 0
+  Bool8Id* = TypeId 1
+  Char8Id* = TypeId 2
+  Int8Id* = TypeId 3
+  Int16Id* = TypeId 4
+  Int32Id* = TypeId 5
+  Int64Id* = TypeId 6
+  UInt8Id* = TypeId 7
+  UInt16Id* = TypeId 8
+  UInt32Id* = TypeId 9
+  UInt64Id* = TypeId 10
+  Float32Id* = TypeId 11
+  Float64Id* = TypeId 12
+  VoidPtrId* = TypeId 13
+  LastBuiltinId* = 13
+
+proc initTypeGraph*(lit: Literals): TypeGraph =
+  result = TypeGraph(nodes: @[
+    TypeNode(x: toX(VoidTy, 0'u32)),
+    TypeNode(x: toX(BoolTy, 8'u32)),
+    TypeNode(x: toX(CharTy, 8'u32)),
+    TypeNode(x: toX(IntTy, 8'u32)),
+    TypeNode(x: toX(IntTy, 16'u32)),
+    TypeNode(x: toX(IntTy, 32'u32)),
+    TypeNode(x: toX(IntTy, 64'u32)),
+    TypeNode(x: toX(UIntTy, 8'u32)),
+    TypeNode(x: toX(UIntTy, 16'u32)),
+    TypeNode(x: toX(UIntTy, 32'u32)),
+    TypeNode(x: toX(UIntTy, 64'u32)),
+    TypeNode(x: toX(FloatTy, 32'u32)),
+    TypeNode(x: toX(FloatTy, 64'u32)),
+    TypeNode(x: toX(APtrTy, 2'u32)),
+    TypeNode(x: toX(VoidTy, 0'u32))
+  ], lit: lit)
+  assert result.nodes.len == LastBuiltinId+2
+
+type
+  TypePatchPos* = distinct int
+
+const
+  InvalidTypePatchPos* = TypePatchPos(-1)
+  LastAtomicValue = VarargsTy
+
+proc isValid(p: TypePatchPos): bool {.inline.} = p.int != -1
+
+proc prepare(tree: var TypeGraph; kind: NirTypeKind): TypePatchPos =
+  result = TypePatchPos tree.nodes.len
+  tree.nodes.add TypeNode(x: toX(kind, 1'u32))
+
+proc isAtom(tree: TypeGraph; pos: int): bool {.inline.} = tree.nodes[pos].kind <= LastAtomicValue
+proc isAtom(tree: TypeGraph; pos: TypeId): bool {.inline.} = tree.nodes[pos.int].kind <= LastAtomicValue
+
+proc patch(tree: var TypeGraph; pos: TypePatchPos) =
+  let pos = pos.int
+  let k = tree.nodes[pos].kind
+  assert k > LastAtomicValue
+  let distance = int32(tree.nodes.len - pos)
+  assert distance > 0
+  tree.nodes[pos].x = toX(k, cast[uint32](distance))
+
+proc len*(tree: TypeGraph): int {.inline.} = tree.nodes.len
+
+template rawSpan(n: TypeNode): int = int(operand(n))
+
+proc nextChild(tree: TypeGraph; pos: var int) {.inline.} =
+  if tree.nodes[pos].kind > LastAtomicValue:
+    assert tree.nodes[pos].operand > 0'u32
+    inc pos, tree.nodes[pos].rawSpan
+  else:
+    inc pos
+
+iterator sons*(tree: TypeGraph; n: TypeId): TypeId =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  while pos < last:
+    yield TypeId pos
+    nextChild tree, pos
+
+template `[]`*(t: TypeGraph; n: TypeId): TypeNode = t.nodes[n.int]
+
+proc elementType*(tree: TypeGraph; n: TypeId): TypeId {.inline.} =
+  assert tree[n].kind in {APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy, ArrayTy, LastArrayTy}
+  result = TypeId(n.int+1)
+
+proc litId*(n: TypeNode): LitId {.inline.} =
+  assert n.kind in {NameVal, IntVal, SizeVal, AlignVal, OffsetVal, AnnotationVal, ObjectTy, UnionTy}
+  result = LitId(n.operand)
+
+proc kind*(tree: TypeGraph; n: TypeId): NirTypeKind {.inline.} = tree[n].kind
+
+proc span(tree: TypeGraph; pos: int): int {.inline.} =
+  if tree.nodes[pos].kind <= LastAtomicValue: 1 else: int(tree.nodes[pos].operand)
+
+proc sons2(tree: TypeGraph; n: TypeId): (TypeId, TypeId) =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  result = (TypeId a, TypeId b)
+
+proc sons3(tree: TypeGraph; n: TypeId): (TypeId, TypeId, TypeId) =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  result = (TypeId a, TypeId b, TypeId c)
+
+proc arrayName*(tree: TypeGraph; n: TypeId): TypeId {.inline.} =
+  assert tree[n].kind == ArrayTy
+  let (_, _, c) = sons3(tree, n)
+  result = c
+
+proc arrayLen*(tree: TypeGraph; n: TypeId): BiggestInt =
+  assert tree[n].kind == ArrayTy
+  let (_, b) = sons2(tree, n)
+  result = tree.lit.numbers[LitId tree[b].operand]
+
+proc returnType*(tree: TypeGraph; n: TypeId): (TypeId, TypeId) =
+  # Returns the positions of the return type + calling convention.
+  var pos = n.int
+  assert tree.nodes[pos].kind == ProcTy
+  let a = n.int+1
+  let b = a + span(tree, a)
+  result = (TypeId b, TypeId a) # not a typo, order is reversed
+
+iterator params*(tree: TypeGraph; n: TypeId): TypeId =
+  var pos = n.int
+  assert tree.nodes[pos].kind == ProcTy
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  nextChild tree, pos
+  nextChild tree, pos
+  while pos < last:
+    yield TypeId pos
+    nextChild tree, pos
+
+proc openType*(tree: var TypeGraph; kind: NirTypeKind): TypePatchPos =
+  assert kind in {APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy,
+    ArrayTy, LastArrayTy, ProcTy, ObjectDecl, UnionDecl,
+    FieldDecl}
+  result = prepare(tree, kind)
+
+template typeInvariant(p: TypePatchPos) =
+  when false:
+    if tree[TypeId(p)].kind == FieldDecl:
+      var k = 0
+      for ch in sons(tree, TypeId(p)):
+        inc k
+      assert k > 2, "damn! " & $k
+
+proc sealType*(tree: var TypeGraph; p: TypePatchPos) =
+  patch tree, p
+  typeInvariant(p)
+
+proc finishType*(tree: var TypeGraph; p: TypePatchPos): TypeId =
+  # Search for an existing instance of this type in
+  # order to reduce memory consumption:
+  patch tree, p
+  typeInvariant(p)
+
+  let s = span(tree, p.int)
+  var i = 0
+  while i < p.int:
+    if tree.nodes[i].x == tree.nodes[p.int].x:
+      var isMatch = true
+      for j in 1..<s:
+        if tree.nodes[j+i].x == tree.nodes[j+p.int].x:
+          discard "still a match"
+        else:
+          isMatch = false
+          break
+      if isMatch:
+        if p.int+s == tree.len:
+          setLen tree.nodes, p.int
+        return TypeId(i)
+    nextChild tree, i
+  result = TypeId(p)
+
+proc nominalType*(tree: var TypeGraph; kind: NirTypeKind; name: string): TypeId =
+  assert kind in {ObjectTy, UnionTy}
+  let content = TypeNode(x: toX(kind, tree.lit.strings.getOrIncl(name)))
+  for i in 0..<tree.len:
+    if tree.nodes[i].x == content.x:
+      return TypeId(i)
+  result = TypeId tree.nodes.len
+  tree.nodes.add content
+
+proc addNominalType*(tree: var TypeGraph; kind: NirTypeKind; name: string) =
+  assert kind in {ObjectTy, UnionTy}
+  tree.nodes.add TypeNode(x: toX(kind, tree.lit.strings.getOrIncl(name)))
+
+proc getTypeTag*(tree: TypeGraph; t: TypeId): string =
+  assert tree[t].kind in {ObjectTy, UnionTy}
+  result = tree.lit.strings[LitId tree[t].operand]
+
+proc addVarargs*(tree: var TypeGraph) =
+  tree.nodes.add TypeNode(x: toX(VarargsTy, 0'u32))
+
+proc getFloat128Type*(tree: var TypeGraph): TypeId =
+  result = TypeId tree.nodes.len
+  tree.nodes.add TypeNode(x: toX(FloatTy, 128'u32))
+
+proc addBuiltinType*(g: var TypeGraph; id: TypeId) =
+  g.nodes.add g[id]
+
+template firstSon*(n: TypeId): TypeId = TypeId(n.int+1)
+
+proc addType*(g: var TypeGraph; t: TypeId) =
+  # We cannot simply copy `*Decl` nodes. We have to introduce `*Ty` nodes instead:
+  if g[t].kind in {ObjectDecl, UnionDecl}:
+    assert g[t.firstSon].kind == NameVal
+    let name = LitId g[t.firstSon].operand
+    if g[t].kind == ObjectDecl:
+      g.nodes.add TypeNode(x: toX(ObjectTy, name))
+    else:
+      g.nodes.add TypeNode(x: toX(UnionTy, name))
+  else:
+    let pos = t.int
+    let L = span(g, pos)
+    let d = g.nodes.len
+    g.nodes.setLen(d + L)
+    assert L > 0
+    for i in 0..<L:
+      g.nodes[d+i] = g.nodes[pos+i]
+
+proc addArrayLen*(g: var TypeGraph; len: int64) =
+  g.nodes.add TypeNode(x: toX(IntVal, g.lit.numbers.getOrIncl(len)))
+
+proc addSize*(g: var TypeGraph; s: int64) =
+  g.nodes.add TypeNode(x: toX(SizeVal, g.lit.numbers.getOrIncl(s)))
+
+proc addOffset*(g: var TypeGraph; offset: int64) =
+  g.nodes.add TypeNode(x: toX(OffsetVal, g.lit.numbers.getOrIncl(offset)))
+
+proc addAlign*(g: var TypeGraph; a: int64) =
+  g.nodes.add TypeNode(x: toX(AlignVal, g.lit.numbers.getOrIncl(a)))
+
+proc addName*(g: var TypeGraph; name: string) =
+  g.nodes.add TypeNode(x: toX(NameVal, g.lit.strings.getOrIncl(name)))
+
+proc addAnnotation*(g: var TypeGraph; name: string) =
+  g.nodes.add TypeNode(x: toX(NameVal, g.lit.strings.getOrIncl(name)))
+
+proc addField*(g: var TypeGraph; name: string; typ: TypeId; offset: int64) =
+  let f = g.openType FieldDecl
+  g.addType typ
+  g.addOffset offset
+  g.addName name
+  sealType(g, f)
+
+proc ptrTypeOf*(g: var TypeGraph; t: TypeId): TypeId =
+  let f = g.openType APtrTy
+  g.addType t
+  result = finishType(g, f)
+
+proc arrayPtrTypeOf*(g: var TypeGraph; t: TypeId): TypeId =
+  let f = g.openType AArrayPtrTy
+  g.addType t
+  result = finishType(g, f)
+
+proc store*(r: var RodFile; g: TypeGraph) =
+  storeSeq r, g.nodes
+
+proc load*(r: var RodFile; g: var TypeGraph) =
+  loadSeq r, g.nodes
+
+proc toString*(dest: var string; g: TypeGraph; i: TypeId) =
+  case g[i].kind
+  of VoidTy: dest.add "void"
+  of IntTy:
+    dest.add "i"
+    dest.addInt g[i].operand
+  of UIntTy:
+    dest.add "u"
+    dest.addInt g[i].operand
+  of FloatTy:
+    dest.add "f"
+    dest.addInt g[i].operand
+  of BoolTy:
+    dest.add "b"
+    dest.addInt g[i].operand
+  of CharTy:
+    dest.add "c"
+    dest.addInt g[i].operand
+  of NameVal, AnnotationVal:
+    dest.add g.lit.strings[LitId g[i].operand]
+  of IntVal, SizeVal, AlignVal, OffsetVal:
+    dest.add $g[i].kind
+    dest.add ' '
+    dest.add $g.lit.numbers[LitId g[i].operand]
+  of VarargsTy:
+    dest.add "..."
+  of APtrTy:
+    dest.add "aptr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of UPtrTy:
+    dest.add "uptr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of AArrayPtrTy:
+    dest.add "aArrayPtr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of UArrayPtrTy:
+    dest.add "uArrayPtr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of ArrayTy:
+    dest.add "Array["
+    let (elems, len, name) = g.sons3(i)
+    toString(dest, g, elems)
+    dest.add ", "
+    toString(dest, g, len)
+    dest.add ", "
+    toString(dest, g, name)
+    dest.add "]"
+  of LastArrayTy:
+    # array of unspecified size as a last field inside an object
+    dest.add "LastArrayTy["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of ObjectTy:
+    dest.add "object "
+    dest.add g.lit.strings[LitId g[i].operand]
+  of UnionTy:
+    dest.add "union "
+    dest.add g.lit.strings[LitId g[i].operand]
+  of ProcTy:
+    dest.add "proc["
+    for t in sons(g, i):
+      dest.add ' '
+      toString(dest, g, t)
+    dest.add "]"
+  of ObjectDecl:
+    dest.add "object["
+    for t in sons(g, i):
+      toString(dest, g, t)
+      dest.add '\n'
+    dest.add "]"
+  of UnionDecl:
+    dest.add "union["
+    for t in sons(g, i):
+      toString(dest, g, t)
+      dest.add '\n'
+    dest.add "]"
+  of FieldDecl:
+    dest.add "field["
+    for t in sons(g, i):
+      toString(dest, g, t)
+      dest.add ' '
+    dest.add "]"
+
+    when false:
+      let (typ, offset, name) = g.sons3(i)
+      toString(dest, g, typ)
+      dest.add ' '
+      toString(dest, g, offset)
+      dest.add ' '
+      toString(dest, g, name)
+
+proc toString*(dest: var string; g: TypeGraph) =
+  var i = 0
+  while i < g.len:
+    dest.add "T<"
+    dest.addInt i
+    dest.add "> "
+    toString(dest, g, TypeId i)
+    dest.add '\n'
+    nextChild g, i
+
+iterator allTypes*(g: TypeGraph; start = 0): TypeId =
+  var i = start
+  while i < g.len:
+    yield TypeId i
+    nextChild g, i
+
+iterator allTypesIncludingInner*(g: TypeGraph; start = 0): TypeId =
+  var i = start
+  while i < g.len:
+    yield TypeId i
+    inc i
+
+proc `$`(g: TypeGraph): string =
+  result = ""
+  toString(result, g)
+
+when isMainModule:
+  var g = initTypeGraph(Literals())
+
+  let a = g.openType ArrayTy
+  g.addBuiltinType Int8Id
+  g.addArrayLen 5
+  g.addName "SomeArray"
+  let finalArrayType = finishType(g, a)
+
+  let obj = g.openType ObjectDecl
+  g.nodes.add TypeNode(x: toX(NameVal, g.lit.strings.getOrIncl("MyType")))
+
+  g.addField "p", finalArrayType, 0
+  sealType(g, obj)
+
+  echo g
--- a/compiler/nir/nirvm.nim
+++ b/compiler/nir/nirvm.nim
--- a/compiler/nir/stringcases.nim
+++ b/compiler/nir/stringcases.nim
@@ -0,0 +1,200 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## included from ast2ir.nim
+
+#[
+
+case s
+of "abc", "abbd":
+  echo 1
+of "hah":
+  echo 2
+of "gah":
+  echo 3
+
+# we produce code like this:
+
+if s[0] <= 'a':
+  if s == "abc: goto L1
+  elif s == "abbd": goto L1
+else:
+  if s[2] <= 'h':
+    if s == "hah": goto L2
+    elif s == "gah": goto L3
+goto afterCase
+
+L1:
+  echo 1
+  goto afterCase
+L2:
+  echo 2
+  goto afterCase
+L3:
+  echo 3
+  goto afterCase
+
+afterCase: ...
+
+]#
+
+# We split the set of strings into 2 sets of roughly the same size.
+# The condition used for splitting is a (position, char) tuple.
+# Every string of length > position for which s[position] <= char is in one
+# set else it is in the other set.
+
+from std/sequtils import addUnique
+
+type
+  Key = (LitId, LabelId)
+
+proc splitValue(strings: BiTable[string]; a: openArray[Key]; position: int): (char, float) =
+  var cand: seq[char] = @[]
+  for t in items a:
+    let s = strings[t[0]]
+    if s.len > position: cand.addUnique s[position]
+
+  result = ('\0', -1.0)
+  for disc in items cand:
+    var hits = 0
+    for t in items a:
+      let s = strings[t[0]]
+      if s.len > position and s[position] <= disc:
+        inc hits
+    # the split is the better, the more `hits` is close to `a.len / 2`:
+    let grade = 100000.0 - abs(hits.float - a.len.float / 2.0)
+    if grade > result[1]:
+      result = (disc, grade)
+
+proc tryAllPositions(strings: BiTable[string]; a: openArray[Key]): (char, int) =
+  var m = 0
+  for t in items a:
+    m = max(m, strings[t[0]].len)
+
+  result = ('\0', -1)
+  var best = -1.0
+  for i in 0 ..< m:
+    let current = splitValue(strings, a, i)
+    if current[1] > best:
+      best = current[1]
+      result = (current[0], i)
+
+type
+  SearchKind = enum
+    LinearSearch, SplitSearch
+  SearchResult* = object
+    case kind: SearchKind
+    of LinearSearch:
+      a: seq[Key]
+    of SplitSearch:
+      span: int
+      best: (char, int)
+
+proc emitLinearSearch(strings: BiTable[string]; a: openArray[Key]; dest: var seq[SearchResult]) =
+  var d = SearchResult(kind: LinearSearch, a: @[])
+  for x in a: d.a.add x
+  dest.add d
+
+proc split(strings: BiTable[string]; a: openArray[Key]; dest: var seq[SearchResult]) =
+  if a.len <= 4:
+    emitLinearSearch strings, a, dest
+  else:
+    let best = tryAllPositions(strings, a)
+    var groupA: seq[Key] = @[]
+    var groupB: seq[Key] = @[]
+    for t in items a:
+      let s = strings[t[0]]
+      if s.len > best[1] and s[best[1]] <= best[0]:
+        groupA.add t
+      else:
+        groupB.add t
+    if groupA.len == 0 or groupB.len == 0:
+      emitLinearSearch strings, a, dest
+    else:
+      let toPatch = dest.len
+      dest.add SearchResult(kind: SplitSearch, span: 1, best: best)
+      split strings, groupA, dest
+      split strings, groupB, dest
+      let dist = dest.len - toPatch
+      assert dist > 0
+      dest[toPatch].span = dist
+
+proc toProblemDescription(c: var ProcCon; n: PNode): (seq[Key], LabelId) =
+  result = (@[], newLabels(c.labelGen, n.len))
+  assert n.kind == nkCaseStmt
+  for i in 1..<n.len:
+    let it = n[i]
+    let thisBranch = LabelId(result[1].int + i - 1)
+    if it.kind == nkOfBranch:
+      for j in 0..<it.len-1:
+        assert it[j].kind in {nkStrLit..nkTripleStrLit}
+        result[0].add (c.lit.strings.getOrIncl(it[j].strVal), thisBranch)
+
+proc decodeSolution(c: var ProcCon; dest: var Tree; s: seq[SearchResult]; i: int;
+                    selector: Value; info: PackedLineInfo) =
+  case s[i].kind
+  of SplitSearch:
+    let thenA = i+1
+    let elseA = thenA + (if s[thenA].kind == LinearSearch: 1 else: s[thenA].span)
+    let best = s[i].best
+
+    let tmp = getTemp(c, Bool8Id, info)
+    buildTyped dest, info, Asgn, Bool8Id:
+      dest.copyTree tmp
+      buildTyped dest, info, Call, Bool8Id:
+        c.addUseCodegenProc dest, "nimStrAtLe", info
+        dest.copyTree selector
+        dest.addIntVal c.lit.numbers, info, c.m.nativeIntId, best[1]
+        dest.addIntVal c.lit.numbers, info, Char8Id, best[0].int
+
+    template then() =
+      c.decodeSolution dest, s, thenA, selector, info
+    template otherwise() =
+      c.decodeSolution dest, s, elseA, selector, info
+    buildIfThenElse tmp, then, otherwise
+    freeTemp c, tmp
+
+  of LinearSearch:
+    let tmp = getTemp(c, Bool8Id, info)
+    for x in s[i].a:
+      buildTyped dest, info, Asgn, Bool8Id:
+        dest.copyTree tmp
+        buildTyped dest, info, Call, Bool8Id:
+          c.addUseCodegenProc dest, "eqStrings", info
+          dest.copyTree selector
+          dest.addStrLit info, x[0]
+      buildIf tmp:
+        c.code.gotoLabel info, Goto, x[1]
+    freeTemp c, tmp
+
+proc genStringCase(c: var ProcCon; n: PNode; d: var Value) =
+  let (problem, firstBranch) = toProblemDescription(c, n)
+  var solution: seq[SearchResult] = @[]
+  split c.lit.strings, problem, solution
+
+  # XXX Todo move complex case selector into a temporary.
+  let selector = c.genx(n[0])
+
+  let info = toLineInfo(c, n.info)
+  decodeSolution c, c.code, solution, 0, selector, info
+
+  let lend = newLabel(c.labelGen)
+  c.code.addLabel info, Goto, lend
+  for i in 1..<n.len:
+    let it = n[i]
+    let thisBranch = LabelId(firstBranch.int + i - 1)
+    c.code.addLabel info, Label, thisBranch
+    if it.kind == nkOfBranch:
+      gen(c, it.lastSon, d)
+      c.code.addLabel info, Goto, lend
+    else:
+      gen(c, it.lastSon, d)
+
+  c.code.addLabel info, Label, lend
+  freeTemp c, selector
--- a/compiler/nir/types2ir.nim
+++ b/compiler/nir/types2ir.nim
@@ -0,0 +1,525 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+import std / [assertions, tables, sets]
+import ".." / [ast, types, options, sighashes, modulegraphs]
+import nirtypes
+
+type
+  TypesCon* = object
+    processed: Table[ItemId, TypeId]
+    processedByName: Table[string, TypeId]
+    recursionCheck: HashSet[ItemId]
+    conf: ConfigRef
+    stringType: TypeId
+
+proc initTypesCon*(conf: ConfigRef): TypesCon =
+  TypesCon(conf: conf, stringType: TypeId(-1))
+
+proc mangle(c: var TypesCon; t: PType): string =
+  result = $sighashes.hashType(t, c.conf)
+
+template cached(c: var TypesCon; t: PType; body: untyped) =
+  result = c.processed.getOrDefault(t.itemId)
+  if result.int == 0:
+    body
+    c.processed[t.itemId] = result
+
+template cachedByName(c: var TypesCon; t: PType; body: untyped) =
+  let key = mangle(c, t)
+  result = c.processedByName.getOrDefault(key)
+  if result.int == 0:
+    body
+    c.processedByName[key] = result
+
+proc typeToIr*(c: var TypesCon; g: var TypeGraph; t: PType): TypeId
+
+proc collectFieldTypes(c: var TypesCon; g: var TypeGraph; n: PNode; dest: var Table[ItemId, TypeId]) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      collectFieldTypes(c, g, n[i], dest)
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    collectFieldTypes(c, g, n[0], dest)
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        collectFieldTypes c, g, lastSon(n[i]), dest
+      else: discard
+  of nkSym:
+    dest[n.sym.itemId] = typeToIr(c, g, n.sym.typ)
+  else:
+    assert false, "unknown node kind: " & $n.kind
+
+proc objectToIr(c: var TypesCon; g: var TypeGraph; n: PNode; fieldTypes: Table[ItemId, TypeId]; unionId: var int) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      objectToIr(c, g, n[i], fieldTypes, unionId)
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    objectToIr(c, g, n[0], fieldTypes, unionId)
+    let u = openType(g, UnionDecl)
+    g.addName "u_" & $unionId
+    inc unionId
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        let subObj = openType(g, ObjectDecl)
+        g.addName "uo_" & $unionId & "_" & $i
+        objectToIr c, g, lastSon(n[i]), fieldTypes, unionId
+        sealType(g, subObj)
+      else: discard
+    sealType(g, u)
+  of nkSym:
+    g.addField n.sym.name.s & "_" & $n.sym.position, fieldTypes[n.sym.itemId], n.sym.offset
+  else:
+    assert false, "unknown node kind: " & $n.kind
+
+proc objectToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  if t[0] != nil:
+    # ensure we emitted the base type:
+    discard typeToIr(c, g, t[0])
+
+  var unionId = 0
+  var fieldTypes = initTable[ItemId, TypeId]()
+  collectFieldTypes c, g, t.n, fieldTypes
+  let obj = openType(g, ObjectDecl)
+  g.addName mangle(c, t)
+  g.addSize c.conf.getSize(t)
+  g.addAlign c.conf.getAlign(t)
+
+  if t[0] != nil:
+    g.addNominalType(ObjectTy, mangle(c, t[0]))
+  else:
+    g.addBuiltinType VoidId # object does not inherit
+    if not lacksMTypeField(t):
+      let f2 = g.openType FieldDecl
+      let voidPtr = openType(g, APtrTy)
+      g.addBuiltinType(VoidId)
+      sealType(g, voidPtr)
+      g.addOffset 0 # type field is always at offset 0
+      g.addName "m_type"
+      sealType(g, f2) # FieldDecl
+
+  objectToIr c, g, t.n, fieldTypes, unionId
+  result = finishType(g, obj)
+
+proc objectHeaderToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  result = g.nominalType(ObjectTy, mangle(c, t))
+
+proc tupleToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  var fieldTypes = newSeq[TypeId](t.len)
+  for i in 0..<t.len:
+    fieldTypes[i] = typeToIr(c, g, t[i])
+  let obj = openType(g, ObjectDecl)
+  g.addName mangle(c, t)
+  g.addSize c.conf.getSize(t)
+  g.addAlign c.conf.getAlign(t)
+
+  var accum = OffsetAccum(maxAlign: 1)
+  for i in 0..<t.len:
+    let child = t[i]
+    g.addField "f_" & $i, fieldTypes[i], accum.offset
+
+    computeSizeAlign(c.conf, child)
+    accum.align(child.align)
+    accum.inc(int32(child.size))
+  result = finishType(g, obj)
+
+proc procToIr(c: var TypesCon; g: var TypeGraph; t: PType; addEnv = false): TypeId =
+  var fieldTypes = newSeq[TypeId](0)
+  for i in 0..<t.len:
+    if t[i] == nil or not isCompileTimeOnly(t[i]):
+      fieldTypes.add typeToIr(c, g, t[i])
+  let obj = openType(g, ProcTy)
+
+  case t.callConv
+  of ccNimCall, ccFastCall, ccClosure: g.addAnnotation "__fastcall"
+  of ccStdCall: g.addAnnotation "__stdcall"
+  of ccCDecl: g.addAnnotation "__cdecl"
+  of ccSafeCall: g.addAnnotation "__safecall"
+  of ccSysCall: g.addAnnotation "__syscall"
+  of ccInline: g.addAnnotation "__inline"
+  of ccNoInline: g.addAnnotation "__noinline"
+  of ccThisCall: g.addAnnotation "__thiscall"
+  of ccNoConvention: g.addAnnotation ""
+
+  for i in 0..<fieldTypes.len:
+    g.addType fieldTypes[i]
+
+  if addEnv:
+    let a = openType(g, APtrTy)
+    g.addBuiltinType(VoidId)
+    sealType(g, a)
+
+  if tfVarargs in t.flags:
+    g.addVarargs()
+  result = finishType(g, obj)
+
+proc nativeInt(c: TypesCon): TypeId =
+  case c.conf.target.intSize
+  of 2: result = Int16Id
+  of 4: result = Int32Id
+  else: result = Int64Id
+
+proc openArrayPayloadType*(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  let e = lastSon(t)
+  let elementType = typeToIr(c, g, e)
+  let arr = g.openType AArrayPtrTy
+  g.addType elementType
+  result = finishType(g, arr) # LastArrayTy
+
+proc openArrayToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  # object (a: ArrayPtr[T], len: int)
+  let e = lastSon(t)
+  let mangledBase = mangle(c, e)
+  let typeName = "NimOpenArray" & mangledBase
+
+  let elementType = typeToIr(c, g, e)
+  #assert elementType.int >= 0, typeToString(t)
+
+  let p = openType(g, ObjectDecl)
+  g.addName typeName
+  g.addSize c.conf.target.ptrSize*2
+  g.addAlign c.conf.target.ptrSize
+
+  let f = g.openType FieldDecl
+  let arr = g.openType AArrayPtrTy
+  g.addType elementType
+  sealType(g, arr) # LastArrayTy
+  g.addOffset 0
+  g.addName "data"
+  sealType(g, f) # FieldDecl
+
+  g.addField "len", c.nativeInt, c.conf.target.ptrSize
+
+  result = finishType(g, p) # ObjectDecl
+
+proc strPayloadType(c: var TypesCon; g: var TypeGraph): (string, TypeId) =
+  result = ("NimStrPayload", TypeId(-1))
+  let p = openType(g, ObjectDecl)
+  g.addName result[0]
+  g.addSize c.conf.target.ptrSize*2
+  g.addAlign c.conf.target.ptrSize
+
+  g.addField "cap", c.nativeInt, 0
+
+  let f = g.openType FieldDecl
+  let arr = g.openType LastArrayTy
+  g.addBuiltinType Char8Id
+  result[1] = finishType(g, arr) # LastArrayTy
+  g.addOffset c.conf.target.ptrSize # comes after the len field
+  g.addName "data"
+  sealType(g, f) # FieldDecl
+
+  sealType(g, p)
+
+proc strPayloadPtrType*(c: var TypesCon; g: var TypeGraph): (TypeId, TypeId) =
+  let (mangled, arrayType) = strPayloadType(c, g)
+  let ffp = g.openType APtrTy
+  g.addNominalType ObjectTy, mangled
+  result = (finishType(g, ffp), arrayType) # APtrTy
+
+proc stringToIr(c: var TypesCon; g: var TypeGraph): TypeId =
+  #[
+
+    NimStrPayload = object
+      cap: int
+      data: UncheckedArray[char]
+
+    NimStringV2 = object
+      len: int
+      p: ptr NimStrPayload
+
+  ]#
+  let payload = strPayloadType(c, g)
+
+  let str = openType(g, ObjectDecl)
+  g.addName "NimStringV2"
+  g.addSize c.conf.target.ptrSize*2
+  g.addAlign c.conf.target.ptrSize
+
+  g.addField "len", c.nativeInt, 0
+
+  let fp = g.openType FieldDecl
+  let ffp = g.openType APtrTy
+  g.addNominalType ObjectTy, "NimStrPayload"
+  sealType(g, ffp) # APtrTy
+  g.addOffset c.conf.target.ptrSize # comes after 'len' field
+  g.addName "p"
+  sealType(g, fp) # FieldDecl
+
+  result = finishType(g, str) # ObjectDecl
+
+proc seqPayloadType(c: var TypesCon; g: var TypeGraph; t: PType): (string, TypeId) =
+  #[
+    NimSeqPayload[T] = object
+      cap: int
+      data: UncheckedArray[T]
+  ]#
+  let e = lastSon(t)
+  result = (mangle(c, e), TypeId(-1))
+  let payloadName = "NimSeqPayload" & result[0]
+
+  let elementType = typeToIr(c, g, e)
+
+  let p = openType(g, ObjectDecl)
+  g.addName payloadName
+  g.addSize c.conf.target.intSize
+  g.addAlign c.conf.target.intSize
+
+  g.addField "cap", c.nativeInt, 0
+
+  let f = g.openType FieldDecl
+  let arr = g.openType LastArrayTy
+  g.addType elementType
+  # DO NOT USE `finishType` here as it is an inner type. This is subtle and we
+  # probably need an even better API here.
+  sealType(g, arr)
+  result[1] = TypeId(arr)
+
+  g.addOffset c.conf.target.ptrSize
+  g.addName "data"
+  sealType(g, f) # FieldDecl
+
+  sealType(g, p)
+
+proc seqPayloadPtrType*(c: var TypesCon; g: var TypeGraph; t: PType): (TypeId, TypeId) =
+  let (mangledBase, arrayType) = seqPayloadType(c, g, t)
+  let ffp = g.openType APtrTy
+  g.addNominalType ObjectTy, "NimSeqPayload" & mangledBase
+  result = (finishType(g, ffp), arrayType) # APtrTy
+
+proc seqToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  #[
+    NimSeqV2*[T] = object
+      len: int
+      p: ptr NimSeqPayload[T]
+  ]#
+  let (mangledBase, _) = seqPayloadType(c, g, t)
+
+  let sq = openType(g, ObjectDecl)
+  g.addName "NimSeqV2" & mangledBase
+  g.addSize c.conf.getSize(t)
+  g.addAlign c.conf.getAlign(t)
+
+  g.addField "len", c.nativeInt, 0
+
+  let fp = g.openType FieldDecl
+  let ffp = g.openType APtrTy
+  g.addNominalType ObjectTy, "NimSeqPayload" & mangledBase
+  sealType(g, ffp) # APtrTy
+  g.addOffset c.conf.target.ptrSize
+  g.addName "p"
+  sealType(g, fp) # FieldDecl
+
+  result = finishType(g, sq) # ObjectDecl
+
+
+proc closureToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  # struct {fn(args, void* env), env}
+  # typedef struct {$n" &
+  #        "N_NIMCALL_PTR($2, ClP_0) $3;$n" &
+  #        "void* ClE_0;$n} $1;$n"
+  let mangledBase = mangle(c, t)
+  let typeName = "NimClosure" & mangledBase
+
+  let procType = procToIr(c, g, t, addEnv=true)
+
+  let p = openType(g, ObjectDecl)
+  g.addName typeName
+  g.addSize c.conf.getSize(t)
+  g.addAlign c.conf.getAlign(t)
+
+  let f = g.openType FieldDecl
+  g.addType procType
+  g.addOffset 0
+  g.addName "ClP_0"
+  sealType(g, f) # FieldDecl
+
+  let f2 = g.openType FieldDecl
+  let voidPtr = openType(g, APtrTy)
+  g.addBuiltinType(VoidId)
+  sealType(g, voidPtr)
+
+  g.addOffset c.conf.target.ptrSize
+  g.addName "ClE_0"
+  sealType(g, f2) # FieldDecl
+
+  result = finishType(g, p) # ObjectDecl
+
+proc bitsetBasetype*(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  let s = int(getSize(c.conf, t))
+  case s
+  of 1: result = UInt8Id
+  of 2: result = UInt16Id
+  of 4: result = UInt32Id
+  of 8: result = UInt64Id
+  else: result = UInt8Id
+
+proc typeToIr*(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  if t == nil: return VoidId
+  case t.kind
+  of tyInt:
+    case int(getSize(c.conf, t))
+    of 2: result = Int16Id
+    of 4: result = Int32Id
+    else: result = Int64Id
+  of tyInt8: result = Int8Id
+  of tyInt16: result = Int16Id
+  of tyInt32: result = Int32Id
+  of tyInt64: result = Int64Id
+  of tyFloat:
+    case int(getSize(c.conf, t))
+    of 4: result = Float32Id
+    else: result = Float64Id
+  of tyFloat32: result = Float32Id
+  of tyFloat64: result = Float64Id
+  of tyFloat128: result = getFloat128Type(g)
+  of tyUInt:
+    case int(getSize(c.conf, t))
+    of 2: result = UInt16Id
+    of 4: result = UInt32Id
+    else: result = UInt64Id
+  of tyUInt8: result = UInt8Id
+  of tyUInt16: result = UInt16Id
+  of tyUInt32: result = UInt32Id
+  of tyUInt64: result = UInt64Id
+  of tyBool: result = Bool8Id
+  of tyChar: result = Char8Id
+  of tyVoid: result = VoidId
+  of tySink, tyGenericInst, tyDistinct, tyAlias, tyOwned, tyRange:
+    result = typeToIr(c, g, t.lastSon)
+  of tyEnum:
+    if firstOrd(c.conf, t) < 0:
+      result = Int32Id
+    else:
+      case int(getSize(c.conf, t))
+      of 1: result = UInt8Id
+      of 2: result = UInt16Id
+      of 4: result = Int32Id
+      of 8: result = Int64Id
+      else: result = Int32Id
+  of tyOrdinal, tyGenericBody, tyGenericParam, tyInferred, tyStatic:
+    if t.len > 0:
+      result = typeToIr(c, g, t.lastSon)
+    else:
+      result = TypeId(-1)
+  of tyFromExpr:
+    if t.n != nil and t.n.typ != nil:
+      result = typeToIr(c, g, t.n.typ)
+    else:
+      result = TypeId(-1)
+  of tyArray:
+    cached(c, t):
+      var n = toInt64(lengthOrd(c.conf, t))
+      if n <= 0: n = 1   # make an array of at least one element
+      let elemType = typeToIr(c, g, t[1])
+      let a = openType(g, ArrayTy)
+      g.addType(elemType)
+      g.addArrayLen n
+      g.addName mangle(c, t)
+      result = finishType(g, a)
+  of tyPtr, tyRef:
+    cached(c, t):
+      let e = t.lastSon
+      if e.kind == tyUncheckedArray:
+        let elemType = typeToIr(c, g, e.lastSon)
+        let a = openType(g, AArrayPtrTy)
+        g.addType(elemType)
+        result = finishType(g, a)
+      else:
+        let elemType = typeToIr(c, g, t.lastSon)
+        let a = openType(g, APtrTy)
+        g.addType(elemType)
+        result = finishType(g, a)
+  of tyVar, tyLent:
+    cached(c, t):
+      let e = t.lastSon
+      if e.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
+        # skip the modifier, `var openArray` is a (ptr, len) pair too:
+        result = typeToIr(c, g, e)
+      else:
+        let elemType = typeToIr(c, g, e)
+        let a = openType(g, APtrTy)
+        g.addType(elemType)
+        result = finishType(g, a)
+  of tySet:
+    let s = int(getSize(c.conf, t))
+    case s
+    of 1: result = UInt8Id
+    of 2: result = UInt16Id
+    of 4: result = UInt32Id
+    of 8: result = UInt64Id
+    else:
+      # array[U8, s]
+      cached(c, t):
+        let a = openType(g, ArrayTy)
+        g.addType(UInt8Id)
+        g.addArrayLen s
+        g.addName mangle(c, t)
+        result = finishType(g, a)
+  of tyPointer, tyNil:
+    # tyNil can happen for code like: `const CRAP = nil` which we have in posix.nim
+    let a = openType(g, APtrTy)
+    g.addBuiltinType(VoidId)
+    result = finishType(g, a)
+  of tyObject:
+    # Objects are special as they can be recursive in Nim. This is easily solvable.
+    # We check if we are already "processing" t. If so, we produce `ObjectTy`
+    # instead of `ObjectDecl`.
+    cached(c, t):
+      if not c.recursionCheck.containsOrIncl(t.itemId):
+        result = objectToIr(c, g, t)
+      else:
+        result = objectHeaderToIr(c, g, t)
+  of tyTuple:
+    cachedByName(c, t):
+      result = tupleToIr(c, g, t)
+  of tyProc:
+    cached(c, t):
+      if t.callConv == ccClosure:
+        result = closureToIr(c, g, t)
+      else:
+        result = procToIr(c, g, t)
+  of tyVarargs, tyOpenArray:
+    cached(c, t):
+      result = openArrayToIr(c, g, t)
+  of tyString:
+    if c.stringType.int < 0:
+      result = stringToIr(c, g)
+      c.stringType = result
+    else:
+      result = c.stringType
+  of tySequence:
+    cachedByName(c, t):
+      result = seqToIr(c, g, t)
+  of tyCstring:
+    cached(c, t):
+      let a = openType(g, AArrayPtrTy)
+      g.addBuiltinType Char8Id
+      result = finishType(g, a)
+  of tyUncheckedArray:
+    # We already handled the `ptr UncheckedArray` in a special way.
+    cached(c, t):
+      let elemType = typeToIr(c, g, t.lastSon)
+      let a = openType(g, LastArrayTy)
+      g.addType(elemType)
+      result = finishType(g, a)
+  of tyUntyped, tyTyped:
+    # this avoids a special case for system.echo which is not a generic but
+    # uses `varargs[typed]`:
+    result = VoidId
+  of tyNone, tyEmpty, tyTypeDesc,
+     tyGenericInvocation, tyProxy, tyBuiltInTypeClass,
+     tyUserTypeClass, tyUserTypeClassInst, tyCompositeTypeClass,
+     tyAnd, tyOr, tyNot, tyAnything, tyConcept, tyIterable, tyForward:
+    result = TypeId(-1)
--- a/compiler/nodekinds.nim
+++ b/compiler/nodekinds.nim
@@ -1,211 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2015 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## NodeKind enum.
-
-type
-  TNodeKind* = enum # order is extremely important, because ranges are used
-                    # to check whether a node belongs to a certain class
-    nkNone,               # unknown node kind: indicates an error
-                          # Expressions:
-                          # Atoms:
-    nkEmpty,              # the node is empty
-    nkIdent,              # node is an identifier
-    nkSym,                # node is a symbol
-    nkType,               # node is used for its typ field
-
-    nkCharLit,            # a character literal ''
-    nkIntLit,             # an integer literal
-    nkInt8Lit,
-    nkInt16Lit,
-    nkInt32Lit,
-    nkInt64Lit,
-    nkUIntLit,            # an unsigned integer literal
-    nkUInt8Lit,
-    nkUInt16Lit,
-    nkUInt32Lit,
-    nkUInt64Lit,
-    nkFloatLit,           # a floating point literal
-    nkFloat32Lit,
-    nkFloat64Lit,
-    nkFloat128Lit,
-    nkStrLit,             # a string literal ""
-    nkRStrLit,            # a raw string literal r""
-    nkTripleStrLit,       # a triple string literal """
-    nkNilLit,             # the nil literal
-                          # end of atoms
-    nkComesFrom,          # "comes from" template/macro information for
-                          # better stack trace generation
-    nkDotCall,            # used to temporarily flag a nkCall node;
-                          # this is used
-                          # for transforming ``s.len`` to ``len(s)``
-
-    nkCommand,            # a call like ``p 2, 4`` without parenthesis
-    nkCall,               # a call like p(x, y) or an operation like +(a, b)
-    nkCallStrLit,         # a call with a string literal
-                          # x"abc" has two sons: nkIdent, nkRStrLit
-                          # x"""abc""" has two sons: nkIdent, nkTripleStrLit
-    nkInfix,              # a call like (a + b)
-    nkPrefix,             # a call like !a
-    nkPostfix,            # something like a! (also used for visibility)
-    nkHiddenCallConv,     # an implicit type conversion via a type converter
-
-    nkExprEqExpr,         # a named parameter with equals: ''expr = expr''
-    nkExprColonExpr,      # a named parameter with colon: ''expr: expr''
-    nkIdentDefs,          # a definition like `a, b: typeDesc = expr`
-                          # either typeDesc or expr may be nil; used in
-                          # formal parameters, var statements, etc.
-    nkVarTuple,           # a ``var (a, b) = expr`` construct
-    nkPar,                # syntactic (); may be a tuple constructor
-    nkObjConstr,          # object constructor: T(a: 1, b: 2)
-    nkCurly,              # syntactic {}
-    nkCurlyExpr,          # an expression like a{i}
-    nkBracket,            # syntactic []
-    nkBracketExpr,        # an expression like a[i..j, k]
-    nkPragmaExpr,         # an expression like a{.pragmas.}
-    nkRange,              # an expression like i..j
-    nkDotExpr,            # a.b
-    nkCheckedFieldExpr,   # a.b, but b is a field that needs to be checked
-    nkDerefExpr,          # a^
-    nkIfExpr,             # if as an expression
-    nkElifExpr,
-    nkElseExpr,
-    nkLambda,             # lambda expression
-    nkDo,                 # lambda block appering as trailing proc param
-    nkAccQuoted,          # `a` as a node
-
-    nkTableConstr,        # a table constructor {expr: expr}
-    nkBind,               # ``bind expr`` node
-    nkClosedSymChoice,    # symbol choice node; a list of nkSyms (closed)
-    nkOpenSymChoice,      # symbol choice node; a list of nkSyms (open)
-    nkHiddenStdConv,      # an implicit standard type conversion
-    nkHiddenSubConv,      # an implicit type conversion from a subtype
-                          # to a supertype
-    nkConv,               # a type conversion
-    nkCast,               # a type cast
-    nkStaticExpr,         # a static expr
-    nkAddr,               # a addr expression
-    nkHiddenAddr,         # implicit address operator
-    nkHiddenDeref,        # implicit ^ operator
-    nkObjDownConv,        # down conversion between object types
-    nkObjUpConv,          # up conversion between object types
-    nkChckRangeF,         # range check for floats
-    nkChckRange64,        # range check for 64 bit ints
-    nkChckRange,          # range check for ints
-    nkStringToCString,    # string to cstring
-    nkCStringToString,    # cstring to string
-                          # end of expressions
-
-    nkAsgn,               # a = b
-    nkFastAsgn,           # internal node for a fast ``a = b``
-                          # (no string copy)
-    nkGenericParams,      # generic parameters
-    nkFormalParams,       # formal parameters
-    nkOfInherit,          # inherited from symbol
-
-    nkImportAs,           # a 'as' b in an import statement
-    nkProcDef,            # a proc
-    nkMethodDef,          # a method
-    nkConverterDef,       # a converter
-    nkMacroDef,           # a macro
-    nkTemplateDef,        # a template
-    nkIteratorDef,        # an iterator
-
-    nkOfBranch,           # used inside case statements
-                          # for (cond, action)-pairs
-    nkElifBranch,         # used in if statements
-    nkExceptBranch,       # an except section
-    nkElse,               # an else part
-    nkAsmStmt,            # an assembler block
-    nkPragma,             # a pragma statement
-    nkPragmaBlock,        # a pragma with a block
-    nkIfStmt,             # an if statement
-    nkWhenStmt,           # a when expression or statement
-    nkForStmt,            # a for statement
-    nkParForStmt,         # a parallel for statement
-    nkWhileStmt,          # a while statement
-    nkCaseStmt,           # a case statement
-    nkTypeSection,        # a type section (consists of type definitions)
-    nkVarSection,         # a var section
-    nkLetSection,         # a let section
-    nkConstSection,       # a const section
-    nkConstDef,           # a const definition
-    nkTypeDef,            # a type definition
-    nkYieldStmt,          # the yield statement as a tree
-    nkDefer,              # the 'defer' statement
-    nkTryStmt,            # a try statement
-    nkFinally,            # a finally section
-    nkRaiseStmt,          # a raise statement
-    nkReturnStmt,         # a return statement
-    nkBreakStmt,          # a break statement
-    nkContinueStmt,       # a continue statement
-    nkBlockStmt,          # a block statement
-    nkStaticStmt,         # a static statement
-    nkDiscardStmt,        # a discard statement
-    nkStmtList,           # a list of statements
-    nkImportStmt,         # an import statement
-    nkImportExceptStmt,   # an import x except a statement
-    nkExportStmt,         # an export statement
-    nkExportExceptStmt,   # an 'export except' statement
-    nkFromStmt,           # a from * import statement
-    nkIncludeStmt,        # an include statement
-    nkBindStmt,           # a bind statement
-    nkMixinStmt,          # a mixin statement
-    nkUsingStmt,          # an using statement
-    nkCommentStmt,        # a comment statement
-    nkStmtListExpr,       # a statement list followed by an expr; this is used
-                          # to allow powerful multi-line templates
-    nkBlockExpr,          # a statement block ending in an expr; this is used
-                          # to allow powerful multi-line templates that open a
-                          # temporary scope
-    nkStmtListType,       # a statement list ending in a type; for macros
-    nkBlockType,          # a statement block ending in a type; for macros
-                          # types as syntactic trees:
-
-    nkWith,               # distinct with `foo`
-    nkWithout,            # distinct without `foo`
-
-    nkTypeOfExpr,         # type(1+2)
-    nkObjectTy,           # object body
-    nkTupleTy,            # tuple body
-    nkTupleClassTy,       # tuple type class
-    nkTypeClassTy,        # user-defined type class
-    nkStaticTy,           # ``static[T]``
-    nkRecList,            # list of object parts
-    nkRecCase,            # case section of object
-    nkRecWhen,            # when section of object
-    nkRefTy,              # ``ref T``
-    nkPtrTy,              # ``ptr T``
-    nkVarTy,              # ``var T``
-    nkConstTy,            # ``const T``
-    nkOutTy,              # ``out T``
-    nkDistinctTy,         # distinct type
-    nkProcTy,             # proc type
-    nkIteratorTy,         # iterator type
-    nkSinkAsgn,           # '=sink(x, y)'
-    nkEnumTy,             # enum body
-    nkEnumFieldDef,       # `ident = expr` in an enumeration
-    nkArgList,            # argument list
-    nkPattern,            # a special pattern; used for matching
-    nkHiddenTryStmt,      # a hidden try statement
-    nkClosure,            # (prc, env)-pair (internally used for code gen)
-    nkGotoState,          # used for the state machine (for iterators)
-    nkState,              # give a label to a code section (for iterators)
-    nkBreakState,         # special break statement for easier code generation
-    nkFuncDef,            # a func
-    nkTupleConstr         # a tuple constructor
-    nkError               # erroneous AST node
-    nkModuleRef           # for .rod file support: A (moduleId, itemId) pair
-    nkReplayAction        # for .rod file support: A replay action
-    nkNilRodNode          # for .rod file support: a 'nil' PNode
-    nkOpenSym             # container for captured sym that can be overriden by local symbols
-
-const
-  nkCallKinds* = {nkCall, nkInfix, nkPrefix, nkPostfix,
-                  nkCommand, nkCallStrLit, nkHiddenCallConv}
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
ringabout	112e274804	switch on	2023-12-11 14:12:55 +00:00
ringabout	f1a7bfce47	switch on	2023-12-11 14:12:47 +00:00
ringabout	68bf6c7f93	what's problem os cancelled CI	2023-12-11 11:00:02 +00:00
ringabout	7cd431804b	test CI	2023-12-11 09:07:41 +00:00
ringabout	01388dc816	Merge branch 'devel' into pr_string_v3	2023-12-11 13:16:03 +08:00
ringabout	bee9baa8bf	reprieve IC	2023-12-09 11:56:17 +00:00
ringabout	147621ec21	fixes a critical issue	2023-12-09 02:41:05 +00:00
ringabout	5bde480596	workaround a cstring conversion bug	2023-12-09 02:34:22 +00:00
ringabout	33f911e691	fixes C++ compilation	2023-12-08 14:13:21 +00:00
ringabout	ec03e476d5	fixes more problems	2023-12-08 08:41:16 +00:00
ringabout	4adb79f7cb	a small fix	2023-12-08 07:29:36 +00:00
ringabout	1da417b818	tests nimSeqsV3	2023-12-08 07:26:32 +00:00
ringabout	7ef0f43f35	basic examples work now	2023-12-08 07:04:15 +00:00
ringabout	da277cf1b8	more fixes	2023-12-07 14:47:51 +00:00
ringabout	cb172328ba	simple cases compile	2023-12-07 13:56:33 +00:00
ringabout	9af21cf719	progress	2023-12-07 12:53:06 +00:00
ringabout	f7bdec6f0d	progress	2023-12-06 14:25:34 +00:00
ringabout	88c0ac44fc	simple additions	2023-12-06 06:09:25 +00:00
ringabout	119cfe8bc8	some improvements	2023-12-06 02:27:05 +00:00
ringabout	ae99903236	wip: intern strings	2023-12-05 14:51:24 +00:00