allows foreign functions having forward decls

fixes 23827; Cyclic proc calls causes infinite memory usage in VM
2026-08-31 10:53:40 +00:00 · 2024-07-12 22:35:17 +08:00 · 2024-07-12 22:10:11 +08:00
1361 changed files with 19282 additions and 78612 deletions
--- a/.github/ISSUE_TEMPLATE/bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/bug_report.yml
@@ -7,26 +7,25 @@ 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.
-
- type: textarea
-  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, including the commit hash may help.
-  validations:
-    required: true
+      - **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
+    
+- type: textarea
+  id: nim-version
+  attributes:
+    label: Nim Version
+    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/dependabot.yml
+++ b/.github/dependabot.yml
@@ -1,11 +0,0 @@
-# To get started with Dependabot version updates, you'll need to specify which
-# package ecosystems to update and where the package manifests are located.
-# Please see the documentation for all configuration options:
-# https://docs.github.com/github/administering-a-repository/configuration-options-for-dependency-updates
-
-version: 2
-updates:
-  - package-ecosystem: "github-actions" # See documentation for possible values
-    directory: "/" # Location of package manifests
-    schedule:
-      interval: "weekly"
--- a/.github/workflows/bisects.yml
+++ b/.github/workflows/bisects.yml
@@ -15,16 +15,9 @@ jobs:
    name: ${{ matrix.platform }}-bisects
    runs-on: ${{ matrix.platform }}
    steps:
-      - uses: actions/checkout@v7
+      - uses: actions/checkout@v4

-      - name: Install OpenSSL (Windows)
-        if: |
-          runner.os == 'Windows'
-        run: choco install openssl.light --version=1.1.1.0  # OpenSSL 3.x removed SSL_library_init
-        shell: 'powershell'
-
-      # v2 wont work here, because uses "hardcoded" nim versions, action "dynamically" finds version with bug.
-      - uses: jiro4989/setup-nim-action@v1  
+      - uses: jiro4989/setup-nim-action@v1
        with:
          nim-version: 'devel'

--- 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-latest
+            os: windows-2019
          - target: osx
-            os: macos-15
+            os: macos-12

    name: ${{ matrix.target }}
    runs-on: ${{ matrix.os }}
@@ -53,7 +53,7 @@ jobs:

    steps:
      - name: 'Checkout'
-        uses: actions/checkout@v7
+        uses: actions/checkout@v4
        with:
          fetch-depth: 2

@@ -109,7 +109,7 @@ jobs:
        if: |
          github.event_name == 'push' && github.ref == 'refs/heads/devel' &&
          matrix.target == 'linux'
-        uses: crazy-max/ghaction-github-pages@v5
+        uses: crazy-max/ghaction-github-pages@v4
        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'
@@ -18,13 +17,9 @@ jobs:
    strategy:
      fail-fast: false
      matrix:
-        os: [ubuntu-latest, macos-latest]
-        batch: ["0_3", "1_3", "2_3"] # list of `index_num`
-        include:
-          - os: ubuntu-latest
-            cpu: amd64
-          - os: macos-latest
-            cpu: arm64
+        os: [ubuntu-20.04, macos-12]
+        cpu: [amd64]
+        batch: ["allowed_failures", "0_3", "1_3", "2_3"] # list of `index_num`
    name: '${{ matrix.os }} (batch: ${{ matrix.batch }})'
    runs-on: ${{ matrix.os }}
    timeout-minutes: 60 # refs bug #18178
@@ -33,27 +28,26 @@ jobs:
      NIM_TESTAMENT_BATCH: ${{ matrix.batch }}
    steps:
      - name: 'Checkout'
-        uses: actions/checkout@v7
+        uses: actions/checkout@v4
        with:
          fetch-depth: 2

-      - name: 'Install node.js'
-        uses: actions/setup-node@v7
+      - name: 'Install node.js 20.x'
+        uses: actions/setup-node@v4
        with:
-          node-version: 24
+          node-version: '20.x'

      - name: 'Install dependencies (Linux amd64)'
        if: runner.os == 'Linux' && matrix.cpu == 'amd64'
        run: |
-          sudo apt-get update -qq
+          sudo apt-fast update -qq
          DEBIAN_FRONTEND='noninteractive' \
-            sudo apt-get install --no-install-recommends -yq \
+            sudo apt-fast install --no-install-recommends -yq \
              libcurl4-openssl-dev libgc-dev libsdl1.2-dev libsfml-dev \
-              valgrind libc6-dbg libblas-dev liblapack-dev libpcre3 xorg-dev
+              valgrind libc6-dbg libblas-dev xorg-dev
      - 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
@@ -11,20 +11,20 @@ jobs:
    strategy:
      fail-fast: false
      matrix:
-        os: [ubuntu-22.04]
+        os: [ubuntu-20.04]
        cpu: [amd64]
    name: '${{ matrix.os }}'
    runs-on: ${{ matrix.os }}
    steps:
      - name: 'Checkout'
-        uses: actions/checkout@v7
+        uses: actions/checkout@v4
        with:
          fetch-depth: 2

-      - name: 'Install node.js'
-        uses: actions/setup-node@v7
+      - name: 'Install node.js 20.x'
+        uses: actions/setup-node@v4
        with:
-          node-version: 24
+          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@v9
+        uses: actions/github-script@v7
        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@v11
+      - uses: actions/stale@v9
        with:
          days-before-pr-stale:    365
          days-before-pr-close:    30
--- a/.gitignore
+++ b/.gitignore
@@ -68,7 +68,6 @@ testament.db
 /csources
 /csources_v1
 /csources_v2
-/csources_v3

 /dist/
 # /lib/fusion # fusion is now unbundled; `git status` should reveal if it's there so users can act on it
@@ -87,7 +86,6 @@ tweeter_test.db

 /tests/megatest.nim
 /tests/ic/*_temp.nim
-/tests/ic/*_mm/
 /tests/navigator/*_temp.nim


--- 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:
@@ -28,24 +28,24 @@ jobs:
 #         # g++-multilib : Depends: gcc-multilib (>= 4:5.3.1-1ubuntu1) but it is not going to be installed
 #         vmImage: 'ubuntu-18.04'
 #         CPU: i386
-      OSX_arm64:
-        vmImage: 'macos-15'
-        CPU: arm64
-      OSX_arm64_cpp:
-        vmImage: 'macos-15'
-        CPU: arm64
+      OSX_amd64:
+        vmImage: 'macOS-12'
+        CPU: amd64
+      OSX_amd64_cpp:
+        vmImage: 'macOS-12'
+        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
@@ -1,168 +1,120 @@
-# 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.
+- `-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.
+- 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 system, use `new` instead.

- 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.
+- `bindMethod` in `std/jsffi` is deprecated, don't use it with closures.

- With `-d:nimPreviewCheckedClose`, the `close` function in the `std/syncio` module now raises an IO exception in case of an error.
+- JS backend now supports lambda lifting for closures. Use `--legacy:jsNoLambdaLifting` to emulate old behavior.

- 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.
-
- With `-d:nimPreviewCStringComparisons`, comparsions (`<`, `>`, `<=`, `>=`) between cstrings switch from reference semantics to value semantics like `==` and `!=`.
-
- `std/parsesql` has been moved to a nimble package, use `nimble` or `atlas` to install it.
-
- With `-d:nimPreviewDuplicateModuleError`, importing two modules that share the same name becomes a compile-time error. This includes importing the same module more than once. Use `import foo as foo1` (or other aliases) to avoid collisions.
-
- Adds the switch `--mangle:nim|cpp`, which selects `nim` or `cpp` style name mangling when used with `debuginfo` on, defaults to `cpp`.
-
- The second parameter of `succ`, `pred`, `inc`, and `dec` in `system` now accepts `SomeInteger` (previously `Ordinal`).
-
- Bitshift operators (`shl`, `shr`, `ashr`) now apply bitmasking to the right operand in the C/C++/VM/JS backends.
-
- Adds a new warning `--warning:ImplicitRangeConversion` that detects downsizing implicit conversions to range types (e.g., `int -> range[0..255]` or `range[1..256] -> range[0..255]`) that could cause runtime panics. Safe conversions like `range[0..255] -> range[0..65535]` and explicit casts do not trigger warnings. `int` to `Natural` and `Positive` conversions do not trigger warnings, which can be enabled with `--warning:systemRangeConversion`.
-
- Procedure compatibility also checks the backend representation of the
-parameter and result types, not just their source-level shape. Use
-`--legacy:procParamTypeBackendAliases` to restore the older behavior.
+- `owner` in `std/macros` is deprecated.

 ## Standard library additions and changes

-[//]: # "Additions:"
-
- Added `system.readRawDataStable`, a companion to `readRawData` that returns a
-  raw `ptr UncheckedArray[char]` into a string's character data which stays valid
-  across moves and copies of the string value. It is available under every string
-  implementation (refc, ARC/ORC and `--strings:sso`) with the same signature, so
-  code can pin an interior buffer pointer today and be ready for `--strings:sso`
-  without `when declared` guards. Under `--strings:sso` it promotes a small inline
-  string to its heap representation first; under the other implementations the data
-  is already heap-resident, so it is equivalent to `readRawData`.
-
- `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.
-
- `std/files` adds:
-  - Exports `CopyFlag` enum and `FilePermission` type for fine-grained control of file operations
-  - New file operation procs with `Path` support:
-    - `getFilePermissions`, `setFilePermissions` for managing permissions
-    - `tryRemoveFile` for file deletion
-    - `copyFile` with configurable buffer size and symlink handling
-    - `copyFileWithPermissions` to preserve file attributes
-    - `copyFileToDir` for copying files into directories
-
- `std/dirs` adds:
-  - New directory operation procs with `Path` support:
-    - `copyDir` with special file handling options
-    - `copyDirWithPermissions` to recursively preserve attributes
-
- `system.setLenUninit` now supports refc, JS and VM backends.
- `system.setLenUninit` for the `string` type. Allows setting length without initializing new memory on growth.
-
- `std/parseopt` now supports multiple parser modes via a `CliMode` enum.
-  Modes include `Nim` (default, fully compatible) and two new experimental modes:
-  `Lax` and `Gnu` for different option parsing behaviors.
-
- `std/symlinks.expandSymlink` now supports Windows symlinks and junctions with
-  POSIX-like single-hop `readlink` semantics.
- `std/nre2` is added to replace deprecated NRE.
-
- `system.typeof` adds a new parameter `modifierMode` to specify how type modifiers are handled.
-
 [//]: # "Changes:"

- `std/math` The `^` symbol now supports floating-point as exponent in addition to the Natural type.
- `min`, `max`, and `sequtils`' `minIndex`, `maxIndex` and `minmax` for `openArray`s now accept a comparison function.
- `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`.
- `std/re` and `std/nre` are deprecated as PCRE library is obsolete.
-  Use https://github.com/nitely/nim-regex or `std/nre2`.
-  See: https://github.com/nim-lang/Nim/issues/23668.
- `std/pegs` now correctly lexes UTF-8 bytes inside bare identifier-style
-  terminals, so case-insensitive matching of non-ASCII terms (e.g. ``\i café``)
-  works without single-quoting.
- `std/uri`: The `?` operator now appends query parameters to an existing query
-  string instead of replacing it. Fixes [#19782](https://github.com/nim-lang/Nim/issues/19782).
- `std/jsonutils`: `fromJson` now throws an exception when converting to `array`/`seq` if the JSON isn't an array instead of silently failing
+- 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 initialize
+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.
+- 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

- 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.
+- `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`.
+
+- 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"))
+    ```
+
+- An experimental option `genericsOpenSym` has been added to allow captured
+  symbols in generic routine bodies 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.
+
+  Since this change may affect runtime behavior, the experimental switch
+  `genericsOpenSym` 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
-  # objs.nim
-  import std/hashes
+  const value = "captured"
+  template foo(x: int, body: untyped) =
+    let value {.inject.} = "injected"
+    body

-  type
-    Obj* = object
-      x*, y*: int
-      z*: string # to be ignored for equality
+  proc old[T](): string =
+    foo(123):
+      return value # warning: a new `value` has been injected, use `bind` or turn on `experimental:genericsOpenSym`
+  echo old[int]() # "captured"

-  proc `==`*(a, b: Obj): bool =
-    a.x == b.x and a.y == b.y
+  {.experimental: "genericsOpenSym".}

-  proc hash*(a: Obj): Hash =
-    $!(hash(a.x) &! hash(a.y))
+  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"
  ```

-  ```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.
-
- Seven more Unicode characters are now parsed as operators, implementing the RFC
-  https://github.com/nim-lang/RFCs/issues/571: `⟑ ⟇ ⩓ ⩔ ■ □ ☆`. They all have the
-  same priority as `*` (multiplication). As with the other Unicode operators, Nim
-  only lexes them; their meaning is up to user code.
-
 ## Compiler changes

- Fixed a bug where `sizeof(T)` inside a `typedesc` template called from a generic type's
-  `when` clause would error with "'sizeof' requires '.importc' types to be '.completeStruct'".
-  The issue was that `hasValuelessStatics` in `semtypinst.nim` didn't recognize
-  `tyTypeDesc(tyGenericParam)` as an unresolved generic parameter.
-
- The JS backend now implements write-through for `var openArray` parameters that
-  receive a `toOpenArray` view (bug #15952): mutations reach the caller's storage
-  instead of silently writing to a copy. Fixed homogeneous numeric arrays
-  (`array[N, T]`, JS typed arrays) slice via `subarray`; `seq` and non-numeric
-  arrays slice via a `{base, off, len}` view. This also covers seq/non-numeric-array
-  write-through, pass-through, re-slicing and `@` (openArray-to-seq) of such views.
+- `--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 `--raw` flag when generating JSON docs to not render markup.
- Added `--stdinfile` flag to name of the file used when running program from stdin (defaults to `stdinfile.nim`)
- Added `--styleCheck:warning` flag to treat style check violations as warnings.
+- koch now allows bootstrapping with `-d:nimHasLibFFI`, replacing the older option of building the compiler directly w/ the `libffi` nimble package in tow.

-## Documentation changes
-
- Added documentation for the `completeStruct` pragma in the manual.
--- 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_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/aliasanalysis.nim
+++ b/compiler/aliasanalysis.nim
@@ -8,7 +8,7 @@ const
                 nkBracketExpr, nkDerefExpr, nkHiddenDeref,
                 nkAddr, nkHiddenAddr,
                 nkObjDownConv, nkObjUpConv}
-  PathKinds1* = {nkHiddenStdConv, nkHiddenSubConv, nkCast}
+  PathKinds1* = {nkHiddenStdConv, nkHiddenSubConv}

 proc skipConvDfa*(n: PNode): PNode =
  result = n
@@ -125,3 +125,4 @@ proc aliases*(obj, field: PNode): AliasKind =
      else:
        result = maybe
    else: assert false # unreachable
+
--- a/compiler/aliases.nim
+++ b/compiler/aliases.nim
@@ -21,49 +21,6 @@ type
  TAnalysisResult* = enum
    arNo, arMaybe, arYes

-  PartFlag* = enum
-    pfStructural    ## use structural prefix-chain detection and tree-walk
-    pfBidirectional ## also check reverse direction per field in nkObjConstr
-
-proc isCompileTimeOnlyNode(n: PNode): bool {.inline.} =
-  ## `typeof` and typedesc/static values describe types at compile time; they
-  ## do not read the runtime location that alias analysis is protecting.
-  n.kind == nkTypeOfExpr or (n.typ != nil and n.typ.isCompileTimeOnly)
-
-func sameLocation(a, b: PNode): bool =
-  template sameConstIndex(a, b: PNode): bool =
-    a.kind in nkLiterals and b.kind in nkLiterals and a.intVal == b.intVal
-  var a = a
-  var b = b
-  while a.kind in {nkHiddenStdConv, nkHiddenSubConv, nkConv}: a = a[1]
-  while b.kind in {nkHiddenStdConv, nkHiddenSubConv, nkConv}: b = b[1]
-  if a.kind != b.kind: return false
-  case a.kind
-  of nkSym: result = a.sym.id == b.sym.id
-  of nkDotExpr, nkCheckedFieldExpr:
-    result = a[1].kind == nkSym and b[1].kind == nkSym and
-             sameLocation(a[0], b[0]) and a[1].sym.id == b[1].sym.id
-  of nkBracketExpr:
-    result = sameLocation(a[0], b[0]) and sameConstIndex(a[1], b[1])
-  of nkObjUpConv, nkObjDownConv, nkDerefExpr, nkHiddenDeref:
-    result = sameLocation(a[0], b[0])
-  else: result = false
-
-proc isAccessorPrefixOf(a, b: PNode): bool =
-  var cur = b
-  while cur.kind in {nkDotExpr, nkBracketExpr, nkCheckedFieldExpr, nkObjUpConv,
-                     nkObjDownConv, nkHiddenDeref, nkDerefExpr,
-                     nkHiddenStdConv, nkHiddenSubConv, nkConv}:
-    if sameLocation(cur, a): return true
-    case cur.kind
-    of nkDotExpr, nkBracketExpr, nkCheckedFieldExpr, nkObjUpConv, nkObjDownConv,
-       nkHiddenDeref, nkDerefExpr:
-      cur = cur[0]
-    of nkHiddenStdConv, nkHiddenSubConv, nkConv:
-      cur = cur[1]
-    else: discard
-  result = sameLocation(cur, a)
-
 proc isPartOfAux(a, b: PType, marker: var IntSet): TAnalysisResult

 proc isPartOfAux(n: PNode, b: PType, marker: var IntSet): TAnalysisResult =
@@ -113,28 +70,14 @@ proc isPartOf(a, b: PType): TAnalysisResult =
  # watch out: parameters reversed because I'm too lazy to change the code...
  result = isPartOfAux(b, a, marker)

-proc isPartOf*(a, b: PNode; flags: set[PartFlag] = {}): TAnalysisResult =
-  ## Checks if location `a` can be part of location `b`: i.e. whether writing to
-  ## `b` could affect what `a` reads. We treat seqs and strings as pointers
-  ## because the code gen often just passes them as such.
+proc isPartOf*(a, b: PNode): TAnalysisResult =
+  ## checks if location `a` can be part of location `b`. We treat seqs and
+  ## strings as pointers because the code gen often just passes them as such.
  ##
  ## Note: `a` can only be part of `b`, if `a`'s type can be part of `b`'s
  ## type. Since however type analysis is more expensive, we perform it only
  ## if necessary.
  ##
-  ## When `pfStructural` is set additional aliasing is detected:
-  ## * a structural prefix of an accessor chain is considered part of it
-  ##   (e.g. `x.f <| x.f.g`). Normally `x.f !<| x.f.g` because the
-  ##   same-kind `nkDotExpr` comparison treats the differing field names as
-  ##   siblings, but `pfStructural` walks the chain to recognise the
-  ##   relationship.
-  ## * Unrecognised node kinds are traversed recursively.
-  ##
-  ## When `pfBidirectional` is set:
-  ## * In `nkObjConstr` the reverse direction `isPartOf(value, a)` is also
-  ##   checked per field value so that reads hidden behind calls/closures
-  ##   are detected.
-  ##
  ## cases:
  ##
  ## YES-cases:
@@ -143,14 +86,13 @@ proc isPartOf*(a, b: PNode; flags: set[PartFlag] = {}): TAnalysisResult =
  ##  x[]  <| x
  ##  x[i] <| x
  ##  x.f  <| x
-  ##  x.f  <| x.f.g   # when pfStructural (prefix chain)
  ##  ```
  ##
  ## NO-cases:
  ## ```
  ## x           !<| y    # depending on type and symbol kind
  ## x[constA]   !<| x[constB]
-  ## x.f         !<| x.g          # sibling fields at same level
+  ## x.f         !<| x.g
  ## x.f         !<| y.f  iff x !<= y
  ## ```
  ##
@@ -162,13 +104,10 @@ proc isPartOf*(a, b: PNode; flags: set[PartFlag] = {}): TAnalysisResult =
  ##
  ##  x[]  ?<| y  depending on type
  ##  ```
-  if a.isCompileTimeOnlyNode or b.isCompileTimeOnlyNode:
-    return arNo
-
  if a.kind == b.kind:
    case a.kind
    of nkSym:
-      const varKinds = {skVar, skTemp, skResult, skProc, skFunc}
+      const varKinds = {skVar, skTemp, skProc, skFunc}
      # same symbol: aliasing:
      if a.sym.id == b.sym.id: result = arYes
      elif a.sym.kind in varKinds or b.sym.kind in varKinds:
@@ -182,7 +121,7 @@ proc isPartOf*(a, b: PNode; flags: set[PartFlag] = {}): TAnalysisResult =
        else:
          result = arNo
    of nkBracketExpr:
-      result = isPartOf(a[0], b[0], flags)
+      result = isPartOf(a[0], b[0])
      if a.len >= 2 and b.len >= 2:
        # array accesses:
        if result == arYes and isDeepConstExpr(a[1]) and isDeepConstExpr(b[1]):
@@ -192,11 +131,7 @@ proc isPartOf*(a, b: PNode; flags: set[PartFlag] = {}): TAnalysisResult =
          var y = if b[1].kind == nkHiddenStdConv: b[1][1] else: b[1]

          if sameValue(x, y): result = arYes
-          elif pfStructural in flags and isAccessorPrefixOf(a, b):
-            result = arYes
          else: result = arNo
-        elif pfStructural in flags and isAccessorPrefixOf(a, b):
-          result = arYes
        # else: maybe and no are accurate
      else:
        # pointer derefs:
@@ -204,25 +139,22 @@ proc isPartOf*(a, b: PNode; flags: set[PartFlag] = {}): TAnalysisResult =
          if isPartOf(a.typ, b.typ) != arNo: result = arMaybe

    of nkDotExpr:
-      result = isPartOf(a[0], b[0], flags)
+      result = isPartOf(a[0], b[0])
      if result != arNo:
        # if the fields are different, it's not the same location
        if a[1].sym.id != b[1].sym.id:
-          if pfStructural in flags and isAccessorPrefixOf(a, b):
-            result = arYes
-          else:
-            result = arNo
+          result = arNo

    of nkHiddenDeref, nkDerefExpr:
-      result = isPartOf(a[0], b[0], flags)
+      result = isPartOf(a[0], b[0])
      # weaken because of indirection:
      if result != arYes:
        if isPartOf(a.typ, b.typ) != arNo: result = arMaybe

    of nkHiddenStdConv, nkHiddenSubConv, nkConv:
-      result = isPartOf(a[1], b[1], flags)
+      result = isPartOf(a[1], b[1])
    of nkObjUpConv, nkObjDownConv, nkCheckedFieldExpr:
-      result = isPartOf(a[0], b[0], flags)
+      result = isPartOf(a[0], b[0])
    else: result = arNo
    # Calls return a new location, so a default of ``arNo`` is fine.
  else:
@@ -235,31 +167,31 @@ proc isPartOf*(a, b: PNode; flags: set[PartFlag] = {}): TAnalysisResult =
    case b.kind
    of Ix0Kinds:
      # a* !<| b.f  iff  a* !<| b
-      result = isPartOf(a, b[0], flags)
+      result = isPartOf(a, b[0])

    of DerefKinds:
      # a* !<| b[] iff
      result = arNo
      if isPartOf(a.typ, b.typ) != arNo:
-        result = isPartOf(a, b[0], flags)
+        result = isPartOf(a, b[0])
        if result == arNo: result = arMaybe

    of Ix1Kinds:
      # a* !<| T(b)  iff a* !<| b
-      result = isPartOf(a, b[1], flags)
+      result = isPartOf(a, b[1])

    of nkSym:
      # b is an atom, so we have to check a:
      case a.kind
      of Ix0Kinds:
        # a.f !<| b*  iff  a.f !<| b*
-        result = isPartOf(a[0], b, flags)
+        result = isPartOf(a[0], b)
      of Ix1Kinds:
-        result = isPartOf(a[1], b, flags)
+        result = isPartOf(a[1], b)

      of DerefKinds:
        if isPartOf(a.typ, b.typ) != arNo:
-          result = isPartOf(a[0], b, flags)
+          result = isPartOf(a[0], b)
          if result == arNo: result = arMaybe
        else:
          result = arNo
@@ -267,34 +199,20 @@ proc isPartOf*(a, b: PNode; flags: set[PartFlag] = {}): TAnalysisResult =
    of nkObjConstr:
      result = arNo
      for i in 1..<b.len:
-        let res = isPartOf(a, b[i][1], flags)
+        let res = isPartOf(a, b[i][1])
        if res != arNo:
          result = res
          if res == arYes: break
-        if pfBidirectional in flags:
-          let res2 = isPartOf(b[i][1], a, {pfStructural})
-          if res2 != arNo:
-            result = res2
-            if res2 == arYes: break
    of nkCallKinds:
      result = arNo
      for i in 1..<b.len:
-        # A call such as `fill(typeof(result.f))` has a compile-time-only
-        # argument. It must not make the object constructor look aliased with
-        # `result.f`; runtime arguments remain subject to the normal analysis.
-        if b[i].isCompileTimeOnlyNode:
-          continue
-        let res = isPartOf(a, b[i], flags)
+        let res = isPartOf(a, b[i])
        if res != arNo:
          result = res
          if res == arYes: break
    of nkBracket:
      if b.len > 0:
-        result = isPartOf(a, b[0], flags)
+        result = isPartOf(a, b[0])
      else:
        result = arNo
-    else:
-      if pfStructural in flags:
-        for i in 0..<b.safeLen:
-          if isPartOf(a, b[i], flags) != arNo: return arMaybe
-      result = arNo
+    else: result = arNo
--- a/compiler/ast.nim
+++ b/compiler/ast.nim
--- a/compiler/ast2nif.nim
+++ b/compiler/ast2nif.nim
--- a/compiler/astalgo.nim
+++ b/compiler/astalgo.nim
@@ -13,7 +13,7 @@

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

 import std/[hashes, intsets]
 import std/strutils except addf
@@ -68,6 +68,8 @@ template mdbg*: bool {.deprecated.} =
 # ---------------------------------------------------------------------------

 proc lookupInRecord*(n: PNode, field: PIdent): PSym
+proc mustRehash*(length, counter: int): bool
+proc nextTry*(h, maxHash: Hash): Hash {.inline.}

 # ------------- table[int, int] ---------------------------------------------
 const
@@ -100,7 +102,7 @@ proc skipConvCastAndClosure*(n: PNode): PNode =
      result = result[1]
    else: break

-proc sameValue*[T: AnyNode](a, b: T): bool =
+proc sameValue*(a, b: PNode): bool =
  result = false
  case a.kind
  of nkCharLit..nkUInt64Lit:
@@ -214,6 +216,10 @@ proc getNamedParamFromList*(list: PNode, ident: PIdent): PSym =
 proc hashNode(p: RootRef): Hash =
  result = hash(cast[pointer](p))

+proc mustRehash(length, counter: int): bool =
+  assert(length > counter)
+  result = (length * 2 < counter * 3) or (length - counter < 4)
+
 import std/tables

 const backrefStyle = "\e[90m"
@@ -478,6 +484,12 @@ proc debug(n: PNode; conf: ConfigRef) =
  this.value(n)
  echo($this.res)

+proc nextTry(h, maxHash: Hash): Hash {.inline.} =
+  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
+  # random-number generation for proof).
+
 proc objectSetContains*(t: TObjectSet, obj: RootRef): bool =
  # returns true whether n is in t
  var h: Hash = hashNode(obj) and high(t.data) # start with real hash value
@@ -525,15 +537,101 @@ proc objectSetContainsOrIncl*(t: var TObjectSet, obj: RootRef): bool =
  inc(t.counter)
  result = false

+proc strTableContains*(t: TStrTable, n: PSym): bool =
+  var h: Hash = n.name.h and high(t.data) # start with real hash value
+  while t.data[h] != nil:
+    if (t.data[h] == n):
+      return true
+    h = nextTry(h, high(t.data))
+  result = false
+
+proc strTableRawInsert(data: var seq[PSym], n: PSym) =
+  var h: Hash = n.name.h and high(data)
+  while data[h] != nil:
+    if data[h] == n:
+      # allowed for 'export' feature:
+      #InternalError(n.info, "StrTableRawInsert: " & n.name.s)
+      return
+    h = nextTry(h, high(data))
+  assert(data[h] == nil)
+  data[h] = n
+
+proc symTabReplaceRaw(data: var seq[PSym], prevSym: PSym, newSym: PSym) =
+  assert prevSym.name.h == newSym.name.h
+  var h: Hash = prevSym.name.h and high(data)
+  while data[h] != nil:
+    if data[h] == prevSym:
+      data[h] = newSym
+      return
+    h = nextTry(h, high(data))
+  assert false
+
+proc symTabReplace*(t: var TStrTable, prevSym: PSym, newSym: PSym) =
+  symTabReplaceRaw(t.data, prevSym, newSym)
+
+proc strTableEnlarge(t: var TStrTable) =
+  var n: seq[PSym]
+  newSeq(n, t.data.len * GrowthFactor)
+  for i in 0..high(t.data):
+    if t.data[i] != nil: strTableRawInsert(n, t.data[i])
+  swap(t.data, n)
+
+proc strTableAdd*(t: var TStrTable, n: PSym) =
+  if mustRehash(t.data.len, t.counter): strTableEnlarge(t)
+  strTableRawInsert(t.data, n)
+  inc(t.counter)
+
+proc strTableInclReportConflict*(t: var TStrTable, n: PSym;
+                                 onConflictKeepOld = false): PSym =
+  # if `t` has a conflicting symbol (same identifier as `n`), return it
+  # otherwise return `nil`. Incl `n` to `t` unless `onConflictKeepOld = true`
+  # and a conflict was found.
+  assert n.name != nil
+  var h: Hash = n.name.h and high(t.data)
+  var replaceSlot = -1
+  while true:
+    var it = t.data[h]
+    if it == nil: break
+    # Semantic checking can happen multiple times thanks to templates
+    # and overloading: (var x=@[]; x).mapIt(it).
+    # So it is possible the very same sym is added multiple
+    # times to the symbol table which we allow here with the 'it == n' check.
+    if it.name.id == n.name.id:
+      if it == n: return nil
+      replaceSlot = h
+    h = nextTry(h, high(t.data))
+  if replaceSlot >= 0:
+    result = t.data[replaceSlot] # found it
+    if not onConflictKeepOld:
+      t.data[replaceSlot] = n # overwrite it with newer definition!
+    return result # but return the old one
+  elif mustRehash(t.data.len, t.counter):
+    strTableEnlarge(t)
+    strTableRawInsert(t.data, n)
+  else:
+    assert(t.data[h] == nil)
+    t.data[h] = n
+  inc(t.counter)
+  result = nil
+
+proc strTableIncl*(t: var TStrTable, n: PSym;
+                   onConflictKeepOld = false): bool {.discardable.} =
+  result = strTableInclReportConflict(t, n, onConflictKeepOld) != nil
+
+proc strTableGet*(t: TStrTable, name: PIdent): PSym =
+  var h: Hash = name.h and high(t.data)
+  while true:
+    result = t.data[h]
+    if result == nil: break
+    if result.name.id == name.id: break
+    h = nextTry(h, high(t.data))
+

 type
  TIdentIter* = object # iterator over all syms with same identifier
    h*: Hash           # current hash
-    name* {.cursor.}: PIdent
+    name*: PIdent

-# String tables are always initialized with non-empty, power-of-two storage,
-# and every probe is masked by `high(tab.data)`.
-{.push boundChecks: off.}
 proc nextIdentIter*(ti: var TIdentIter, tab: TStrTable): PSym =
  # hot spots
  var h = ti.h and high(tab.data)
@@ -551,7 +649,6 @@ proc nextIdentIter*(ti: var TIdentIter, tab: TStrTable): PSym =
  else:
    result = nil
  ti.h = nextTry(h, high(tab.data))
-{.pop.}

 proc initIdentIter*(ti: var TIdentIter, tab: TStrTable, s: PIdent): PSym =
  ti.h = s.h
@@ -616,78 +713,6 @@ iterator items*(tab: TStrTable): PSym =
    yield s
    s = nextIter(it, tab)

-proc isNil(x: ItemId): bool {.inline.} =
-  x.module == 0 and x.item == 0
-
-proc hasEmptySlot[T](data: TIdPairSeq[T]): bool =
-  for h in 0..high(data):
-    if isNil(data[h].key):
-      return true
-  result = false
-
-proc idTableRawGet[T](t: TIdTable[T], key: int): int =
-  var h: Hash
-  h = key and high(t.data)    # start with real hash value
-  while not isNil(t.data[h].key):
-    if toId(t.data[h].key) == key:
-      return h
-    h = nextTry(h, high(t.data))
-  result = - 1
-
-proc getOrDefault*[T](t: TIdTable[T], key: ItemId): T =
-  var index = idTableRawGet(t, toId(key))
-  if index >= 0: result = t.data[index].val
-  else: result = default(T)
-
-template idTableGet*[T](t: TIdTable[T], key: PSym): T =
-  getOrDefault(t, key.itemId)
-
-template idTableGet*[T](t: TIdTable[T], key: PType): T =
-  ## Type-keyed tables are BINDING tables: an `exactReplica` must find what its
-  ## original bound, hence `bindingId` and not the type's own identity.
-  getOrDefault(t, key.bindingId)
-
-proc idTableRawInsert[T](data: var TIdPairSeq[T], key: ItemId, val: T) =
-  var h: Hash
-  let keyId = toId(key)
-  h = keyId and high(data)
-  while not isNil(data[h].key):
-    assert(toId(data[h].key) != keyId)
-    h = nextTry(h, high(data))
-  assert(isNil(data[h].key))
-  data[h].key = key
-  data[h].val = val
-
-proc `[]=`*[T](t: var TIdTable[T], key: ItemId, val: T) =
-  var
-    index: int
-    n: TIdPairSeq[T]
-  index = idTableRawGet(t, toId(key))
-  if index >= 0:
-    assert(not isNil(t.data[index].key))
-    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 not isNil(t.data[i].key):
-          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)
-
-template idTablePut*[T](t: var TIdTable[T], key: PSym, val: T) =
-  t[key.itemId] = val
-
-template idTablePut*[T](t: var TIdTable[T], key: PType, val: T) =
-  t[key.bindingId] = val
-
-iterator idTablePairs*[T](t: TIdTable[T]): tuple[key: ItemId, val: T] =
-  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)
@@ -740,7 +765,7 @@ proc listSymbolNames*(symbols: openArray[PSym]): string =
      result.add ", "
    result.add sym.name.s

-proc isDiscriminantField*(n: AnyNode): bool =
-  if n.kind == nkCheckedFieldExpr: sfDiscriminant in n.firstSon.secondSon.sym.flags
-  elif n.kind == nkDotExpr: sfDiscriminant in n.secondSon.sym.flags
+proc isDiscriminantField*(n: PNode): bool =
+  if n.kind == nkCheckedFieldExpr: sfDiscriminant in n[0][1].sym.flags
+  elif n.kind == nkDotExpr: sfDiscriminant in n[1].sym.flags
  else: false
--- a/compiler/astdef.nim
+++ b/compiler/astdef.nim
--- a/compiler/astyaml.nim
+++ b/compiler/astyaml.nim
@@ -43,13 +43,13 @@ proc flagsToStr[T](flags: set[T]): string =
 proc lineInfoToStr*(conf: ConfigRef; info: TLineInfo): string =
  result = "["
  result.addYamlString(toFilename(conf, info))
-  result.addf ", $1, $2]", toLinenumber(info), toColumn(info)
+  result.addf ", $1, $2]", [toLinenumber(info), toColumn(info)]

-proc treeToYamlAux(res: var string; conf: ConfigRef; n: PNode; marker: var IntSet; nl: bool, indent, maxRecDepth: int)
-proc symToYamlAux(res: var string; conf: ConfigRef; n: PSym; marker: var IntSet; nl: bool, indent, maxRecDepth: int)
-proc typeToYamlAux(res: var string; conf: ConfigRef; n: PType; marker: var IntSet; nl: bool, indent, maxRecDepth: int)
+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; nl: bool, indent: int; 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):
@@ -57,12 +57,10 @@ proc symToYamlAux(res: var string; conf: ConfigRef; n: PSym; marker: var IntSet;
  else:
    let istr = spaces(indent * 4)

-    if nl:
-      res.addf("\n$1", istr)
    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, true, indent + 1, maxRecDepth - 1)
+    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)])
@@ -70,65 +68,61 @@ proc symToYamlAux(res: var string; conf: ConfigRef; n: PSym; marker: var IntSet;
      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, true, indent + 1, maxRecDepth - 1)
+    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: ", [istr])
-    res.treeToYamlAux(conf, n.loc.lode, marker, true, indent + 1, maxRecDepth - 1)
+    res.addf("\n$1r: $2", [istr, n.loc.r])
+    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; nl: bool, indent: int; maxRecDepth: int) =
+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)
-    if nl:
-      res.addf("\n$1", istr)
    res.addf("kind: $2", [istr, makeYamlString($n.kind)])
-    res.addf("\n$1sym: ", istr)
-    res.symToYamlAux(conf, n.sym, marker, true, indent + 1, maxRecDepth - 1)
-    res.addf("\n$1n: ", istr)
-    res.treeToYamlAux(conf, n.n, marker, true, indent + 1, maxRecDepth - 1)
+    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:", istr)
+      res.addf("\n$1sons:")
      for a in n.kids:
-        res.addf("\n$1  - ", istr)
-        res.typeToYamlAux(conf, a, marker, false, indent + 1, maxRecDepth - 1)
+        res.addf("\n  - ")
+        res.typeToYamlAux(conf, a, marker, indent + 1, maxRecDepth - 1)

-proc treeToYamlAux(res: var string; conf: ConfigRef; n: PNode; marker: var IntSet; nl: bool, indent: int;
+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)
-    if nl:
-      res.addf("\n$1", istr)
    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 .. nkUInt64Lit:
+      of nkCharLit .. nkInt64Lit:
        res.addf("\n$1intVal: $2", [istr, $(n.intVal)])
-      of nkFloatLit .. nkFloat128Lit:
+      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, true, indent + 1, maxRecDepth)
+        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)])
@@ -139,22 +133,22 @@ proc treeToYamlAux(res: var string; conf: ConfigRef; n: PNode; marker: var IntSe
          res.addf("\n$1sons: ", [istr])
          for i in 0 ..< n.len:
            res.addf("\n$1  - ", [istr])
-            res.treeToYamlAux(conf, n[i], marker, false, indent + 1, maxRecDepth - 1)
+            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, true, indent + 1, maxRecDepth)
+        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, false, indent, maxRecDepth)
+  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, false, indent, maxRecDepth)
+  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, false, indent, maxRecDepth)
+  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/bnode.nim
+++ b/compiler/bnode.nim
--- a/compiler/bodynav.nim
+++ b/compiler/bodynav.nim
@@ -1,335 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2026 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## `BodyNav` — a scope-chained navigator over a `.bif` routine body.
-##
-## Ported from Nimony's `nimony/typenav.nim` (`TypeCache` / `TypeScope`). The
-## idea being stolen is not the type algebra — we do not need it, `typ` returns
-## a fully materialized `PType` — but the SHAPE of the resolution context:
-##
-## * a chain of scope frames, each a small table, linked to its parent;
-## * `openScope` / `closeScope` / `registerLocal`, called BY THE TRAVERSAL as it
-##   descends and as it walks past each definition;
-## * a lookup that consults the chain and, on a miss, falls through to the
-##   module index (`typenav`'s `tryLoadSym`; here the decoder's own
-##   `symFromCursor`).
-##
-## The consequence is the point: the scope is a PRODUCT OF THE WALK. Nothing is
-## snapshotted, so nothing can be stale, and a reader that starts at the top of
-## a body and descends always has exactly the definitions it has already passed.
-##
-## WHAT THIS REPLACES. `ast2nif.PendingBody` stashes `localSyms` — a COPY of the
-## enclosing sym def's local symbols, taken when the body was deferred — and
-## `bnode`'s `BodyScope` then copies it again. `materializeLazyBody` loads the
-## body with its own `var pb`, so every definition the load creates lands in a
-## table that is discarded on return. A cursor-side reader holding the earlier
-## copy therefore cannot see them, and would mint its own `PSym` for the same
-## name: two objects, one symbol.
-##
-## HOW BIG THAT PROBLEM ACTUALLY IS, measured rather than assumed. Build with
-## `-d:icLocalSymStats` and every process reports its `localSyms` traffic on
-## exit. Over a full `--ic:on` build of the standard-library closure (104
-## backend processes):
-##
-##     localHit=0  fieldStub=2  miss=0  sdReg=5902  extractReg=45
-##
-## Definitions register constantly and NOT ONE use ever resolves through the
-## table. The reason is `ast2nif.isLocalSym`, which returns a hardwired `false`:
-## every symbol is emitted with a module suffix and resolves through the
-## decoder's global `syms` memo, so both spellings get the same `PSym` whatever
-## either one has cached. The 5902 registrations are object FIELDS, whose uses
-## deliberately go to `loadFieldStub` instead.
-##
-## So the stale snapshot is a LATENT hazard, not a live bug, and this module is
-## not a bug fix — it is the mechanism that keeps it latent once `isLocalSym`
-## stops being `false`, or once a body-local name appears for any other reason.
-## Said plainly so nobody has to re-derive it: today the nav changes no answers,
-## and the grinder in `cgen` proves that by requiring the navigated symbol to be
-## the same object the `PNode` loader produced, at every node of every body.
-##
-## It is not decorative either, and that also has a number. Over the same build,
-## the grinder's traversal reports `navHits=42236 navFallbacks=12658
-## navRegistered=311`: the chain answers 77% of lookups, and 311 definitions are
-## registered by the walk rather than read from a table someone filled in
-## earlier. Sabotaging the key (truncating it to three characters, so
-## `c_fwrite` and `c_fflush` collide) makes the grinder fail on the first body
-## it reaches — so a clean run means the resolution is right, not that the
-## lookup never happened.
-##
-## FIELDS ARE NOT REGISTERED, and that is deliberate. `loadFieldStub` mints a
-## fresh stub per use because two distinct fields can share a name (and a
-## position) across types — `a.x` and `b.x` in one body are two different
-## symbols. Caching a field by its bare name would hand the second use the first
-## one's stub, and its type. The nav skips field names entirely and leaves that
-## path exactly as it was.
-
-import std / tables
-import ast, ast2nif
-
-when defined(nimPreviewSlimSystem):
-  import std / assertions
-
-import "../dist/nimony/src/lib/nifcore" except pool
-
-type
-  NavScopeKind* = enum
-    nsBlock,                ## an ordinary nested scope
-    nsRoutine               ## a routine boundary — see `crossedRoutines`
-
-  NavScope {.acyclic.} = ref object
-    locals: Table[string, PSym]
-    parent: NavScope
-    kind: NavScopeKind
-
-  BridgeTables* = ref object
-    ## The side tables of an IN-PROCESS bridged buffer (`nodebridge.nim`).
-    ## A `.bif` names its symbols because the reader is a different process; a
-    ## buffer built and read inside ONE process does not have to, and paying the
-    ## name round trip anyway would be worse than pointless — it is what makes
-    ## the file path unable to give a field a stable identity (`loadFieldStub`
-    ## mints per use). Here a symbol reference is an index and resolution hands
-    ## back the very same object, so `symAt` is exact and idempotent for every
-    ## symbol kind, fields included.
-    syms*: seq[PSym]
-    types*: seq[PType]
-    origins*: Table[int, PNode]
-      ## Token position -> the `PNode` encoded there, so a cursor can name the
-      ## node it came from. Lives here rather than in `BridgeBuf` because the
-      ## lookup has to be reachable from wherever a location is built, which is
-      ## everywhere in the generator — the same reason `syms` is here.
-    buf*: ptr TokenBuf
-      ## The buffer `origins` is keyed against; `cursorToPosition` needs it.
-      ## Borrowed, not owned: it points into the `BridgeBuf` that a scoped
-      ## `withBridge` is currently reading, and never outlives it.
-
-  BodyNav* = object
-    ## The resolution context for ONE routine body. `base` is what the decoder
-    ## itself needs (the owning module plus a table `loadSymStub` can write
-    ## into); the frame chain on top of it is this module's contribution.
-    ##
-    ## `bridge` is non-nil only while reading a bridged buffer. It is consulted
-    ## FIRST and, when it answers, it answers exactly — there is no fallback,
-    ## because a `(bsym …)` index that the tables cannot resolve is a corrupt
-    ## buffer, not a cache miss.
-    base*: BodyScope
-    bridge*: BridgeTables
-    current: NavScope
-    hits*: int              ## resolved from the chain
-    fallbacks*: int         ## resolved through the decoder
-    registered*: int        ## definitions the walk registered
-
-proc originAt*(t: BridgeTables; c: Cursor): PNode =
-  ## The source node a cursor was encoded from, or nil when there is none (a
-  ## `DotToken`, or a cursor that is not at a node head).
-  if t == nil or t.buf == nil: return nil
-  result = t.origins.getOrDefault(cursorToPosition(t.buf[], c), nil)
-
-proc initBodyNav*(base: sink BodyScope): BodyNav =
-  ## A nav over a body, seeded with whatever resolution context the decoder
-  ## handed out. The root frame is a routine frame: a body IS one.
-  result = BodyNav(base: base,
-                   current: NavScope(locals: initTable[string, PSym](),
-                                     parent: nil, kind: nsRoutine))
-
-proc initBridgeNav*(tables: BridgeTables): BodyNav =
-  ## A nav over an in-process bridged buffer. `base` stays empty — a bridged
-  ## buffer names nothing, so there is nothing for the decoder to resolve — but
-  ## the ROOT FRAME still has to exist: a walk brackets its descent with
-  ## `openScope`/`closeScope`, and a nav without a root frame makes the first
-  ## `closeScope` pop past the bottom.
-  result = BodyNav(bridge: tables,
-                   current: NavScope(locals: initTable[string, PSym](),
-                                     parent: nil, kind: nsRoutine))
-
-proc openScope*(nav: var BodyNav; kind = nsBlock) {.inline.} =
-  nav.current = NavScope(locals: initTable[string, PSym](),
-                         parent: nav.current, kind: kind)
-
-proc closeScope*(nav: var BodyNav) {.inline.} =
-  doAssert nav.current.parent != nil, "closeScope past the root frame"
-  nav.current = nav.current.parent
-
-template withScope*(nav: var BodyNav; kind: NavScopeKind; body: untyped) =
-  openScope(nav, kind)
-  try:
-    body
-  finally:
-    closeScope(nav)
-
-proc registerLocal*(nav: var BodyNav; name: string; s: PSym) {.inline.} =
-  ## Record a definition the walk has just passed, in the innermost frame.
-  nav.current.locals[name] = s
-  inc nav.registered
-
-proc lookupLocal*(nav: BodyNav; name: string): PSym =
-  ## The chain only. `nil` when nothing in scope carries this name.
-  var it {.cursor.} = nav.current
-  while it != nil:
-    let s = it.locals.getOrDefault(name)
-    if s != nil: return s
-    it = it.parent
-  result = nil
-
-proc crossedRoutines*(nav: BodyNav; name: string): int =
-  ## How many routine frames separate the use from the definition — 0 when the
-  ## definition is in the current routine. `typenav` computes the same thing as
-  ## `LocalInfo.crossedProc`, and it is what tells a closure pass that a name is
-  ## captured rather than local. Nothing consumes it here yet; it is the reason
-  ## the frames carry a kind at all, and dropping the kind would make it
-  ## unrecoverable later.
-  var it {.cursor.} = nav.current
-  var crossed = 0
-  while it != nil:
-    if it.locals.getOrDefault(name) != nil: return crossed
-    if it.kind == nsRoutine: inc crossed
-    it = it.parent
-  result = -1
-
-# ---------------------------------------------------------------------------
-# Names
-#
-# A symbol reaches the reader in four shapes and they all NAME the same thing;
-# `navName` is the one place that knows which token holds the name, so the
-# lookup key is derived identically no matter which wrapper the writer chose.
-
-proc navName*(n: Cursor): string =
-  ## The NIF name a token denotes, or `""` when the token names no symbol.
-  case nifcore.kind(n)
-  of Symbol, SymbolDef:
-    result = symName(n)
-  of TagLit:
-    let tag = n.tags.tagName(cursorTagId(n))
-    if tag == symDefTagName:
-      let name = childCursor(n)
-      result = if nifcore.kind(name) in {Symbol, SymbolDef}: symName(name) else: ""
-    elif tag == hiddenTypeTagName:
-      # `(ht <type> <sym>)`
-      var inner = childCursor(n)
-      skip inner
-      result = navName(inner)
-    elif tag == symNodeFlagsTagName:
-      # `(nflags <flags> <symnode>)`
-      var inner = childCursor(n)
-      skip inner
-      result = navName(inner)
-    else:
-      result = ""
-  else:
-    result = ""
-
-proc symToken*(n: Cursor): Cursor =
-  ## The token that actually NAMES the symbol, with the wrappers stripped.
-  ## `loadSymStub` accepts a `Symbol`, a `SymbolDef` or an `(sd ...)` and
-  ## rejects everything else, so the `(ht ...)` / `(nflags ...)` forms have to be
-  ## peeled here rather than at each call site — the same peeling `navName` does
-  ## for the key, kept beside it so the two cannot drift apart.
-  result = n
-  while nifcore.kind(result) == TagLit:
-    let tag = result.tags.tagName(cursorTagId(result))
-    if tag == hiddenTypeTagName or tag == symNodeFlagsTagName:
-      var inner = childCursor(result)
-      skip inner            # the explicit type / the node flags
-      result = inner
-    else:
-      break
-
-proc cacheFrame(nav: var BodyNav): NavScope =
-  ## Where a decoder-resolved name is remembered: the nearest ROUTINE frame.
-  ## Not the innermost frame — a `.bif` name is unique within its module (see
-  ## `isLocalSym`), so its meaning cannot change between frames, and caching it
-  ## deeper would only throw it away sooner. Not the root either, so that a
-  ## nested routine's names die with the nested routine.
-  result = nav.current
-  while result.kind != nsRoutine and result.parent != nil:
-    result = result.parent
-
-proc bridgeIndex(n: Cursor; tag: string): int =
-  ## The `<intlit>` payload of a `(bsym …)` / `(btyp …)` token, or -1 when `n`
-  ## is not that shape.
-  result = -1
-  if nifcore.kind(n) == TagLit and n.tags.tagName(cursorTagId(n)) == tag:
-    let payload = childCursor(n)
-    if nifcore.kind(payload) == IntLit:
-      result = int(nifcore.intVal(payload))
-
-proc symAt*(nav: var BodyNav; n: Cursor): PSym =
-  ## The symbol a token names: the bridge first (exact), then the chain, then
-  ## the decoder.
-  if nav.bridge != nil:
-    let idx = bridgeIndex(symToken(n), bridgeSymTagName)
-    if idx >= 0:
-      doAssert idx < nav.bridge.syms.len,
-        "bridged sym index out of range: " & $idx
-      inc nav.hits
-      return nav.bridge.syms[idx]
-  let name = navName(n)
-  if name.len > 0:
-    let cached = lookupLocal(nav, name)
-    if cached != nil:
-      inc nav.hits
-      return cached
-  inc nav.fallbacks
-  result = symFromCursor(program, symToken(n), nav.base)
-  if result != nil and name.len > 0 and not isFieldNifName(name):
-    cacheFrame(nav).locals[name] = result
-
-proc typeAt*(nav: var BodyNav; n: Cursor): PType =
-  ## Types are not navigated: `ast2nif` already materializes them lazily from
-  ## the module's type index, keyed by name, so there is no per-body state to
-  ## keep and nothing a frame could cache that the decoder does not already.
-  if nav.bridge != nil:
-    if nifcore.kind(n) == DotToken: return nil
-    let idx = bridgeIndex(n, bridgeTypeTagName)
-    if idx >= 0:
-      doAssert idx < nav.bridge.types.len,
-        "bridged type index out of range: " & $idx
-      return nav.bridge.types[idx]
-  result = typeFromCursor(program, n, nav.base)
-
-# ---------------------------------------------------------------------------
-# Registration during a walk
-
-proc registerDefHere*(nav: var BodyNav; n: Cursor): bool {.discardable.} =
-  ## Register `n` if `n` ITSELF is a definition; do not descend. This is the
-  ## incremental half: a walk calls it on each child before recursing into it,
-  ## so a use can only resolve from the chain to a definition the walk has
-  ## already passed. A use that precedes its definition simply misses and falls
-  ## through to the decoder, which is the behaviour there was before — the nav
-  ## degrades to the old path rather than answering wrongly.
-  result = false
-  if nifcore.kind(n) == TagLit and
-     n.tags.tagName(cursorTagId(n)) == symDefTagName:
-    let name = navName(n)
-    if name.len > 0 and not isFieldNifName(name):
-      let s = symFromCursor(program, n, nav.base)
-      if s != nil:
-        registerLocal(nav, name, s)
-        result = true
-
-proc registerDefs*(nav: var BodyNav; n: Cursor) =
-  ## Register every definition in the SUBTREE at `n` — `typenav.registerLocals`
-  ## with the recursion left in, because a Nim body puts `nkIdentDefs` under an
-  ## `nkVarSection` under the statement list rather than declaring at one level.
-  ##
-  ## Call it on entering a scope to get the eager behaviour (every definition
-  ## known before any use is resolved, which is what a RANDOM-ACCESS reader
-  ## needs), or per statement to get the incremental one (only definitions
-  ## already walked past are visible, which is what a real pass wants and what
-  ## makes use-before-def detectable rather than silently working).
-  if nifcore.kind(n) == TagLit and
-     n.tags.tagName(cursorTagId(n)) == symDefTagName:
-    let name = navName(n)
-    if name.len > 0 and not isFieldNifName(name):
-      let s = symFromCursor(program, n, nav.base)
-      if s != nil: registerLocal(nav, name, s)  # `(sd ...)` needs no peeling
-    return
-  var c = childCursor(n)
-  while c.hasMore:
-    registerDefs(nav, c)
-    skip c
--- a/compiler/btrees.nim
+++ b/compiler/btrees.nim
@@ -69,7 +69,7 @@ proc copyHalf[Key, Val](h, result: Node[Key, Val]) =
      result.links[j] = h.links[Mhalf + j]
  else:
    for j in 0..<Mhalf:
-      when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc) or defined(gcYrc):
+      when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc):
        result.vals[j] = move h.vals[Mhalf + j]
      else:
        shallowCopy(result.vals[j], h.vals[Mhalf + j])
@@ -92,7 +92,7 @@ proc insert[Key, Val](h: Node[Key, Val], key: Key, val: Val): Node[Key, Val] =
      if less(key, h.keys[j]): break
      inc j
    for i in countdown(h.entries, j+1):
-      when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc) or defined(gcYrc):
+      when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc):
        h.vals[i] = move h.vals[i-1]
      else:
        shallowCopy(h.vals[i], h.vals[i-1])
--- a/compiler/cbuilderbase.nim
+++ b/compiler/cbuilderbase.nim
@@ -1,164 +0,0 @@
-import ropes, int128
-
-type
-  Snippet* = string
-  Builder* = object
-    buf*: string
-    indents*: int
-
-template newBuilder*(s: string): Builder =
-  Builder(buf: s)
-
-proc extract*(builder: Builder): Snippet =
-  builder.buf
-
-proc add*(builder: var Builder, s: string) =
-  builder.buf.add(s)
-
-proc add*(builder: var Builder, s: char) =
-  builder.buf.add(s)
-
-proc addNewline*(builder: var Builder) =
-  builder.add('\n')
-  for i in 0 ..< builder.indents:
-    builder.add('\t')
-
-proc addLineEnd*(builder: var Builder, s: string) =
-  builder.add(s)
-  builder.addNewline()
-
-proc addLineEndIndent*(builder: var Builder, s: string) =
-  inc builder.indents
-  builder.add(s)
-  builder.addNewline()
-
-proc addDedent*(builder: var Builder, s: string) =
-  if builder.buf.len > 0 and builder.buf[^1] == '\t':
-    builder.buf.setLen(builder.buf.len - 1)
-  builder.add(s)
-  dec builder.indents
-
-proc addLineEndDedent*(builder: var Builder, s: string) =
-  builder.addDedent(s)
-  builder.addNewline()
-
-proc addLineComment*(builder: var Builder, comment: string) =
-  # probably no-op on nifc
-  builder.add("// ")
-  builder.add(comment)
-  builder.addNewline()
-
-proc addIntValue*(builder: var Builder, val: int) =
-  builder.buf.addInt(val)
-
-proc addIntValue*(builder: var Builder, val: int64) =
-  builder.buf.addInt(val)
-
-proc addIntValue*(builder: var Builder, val: uint64) =
-  builder.buf.addInt(val)
-
-proc addIntValue*(builder: var Builder, val: Int128) =
-  builder.buf.addInt128(val)
-
-template cIntValue*(val: int): Snippet = $val
-template cIntValue*(val: int64): Snippet = $val
-template cIntValue*(val: uint64): Snippet = $val
-template cIntValue*(val: Int128): Snippet = $val
-
-template cUintValue*(val: uint): Snippet = $val & "U"
-
-import std/formatfloat
-
-proc addFloatValue*(builder: var Builder, val: float) =
-  builder.buf.addFloat(val)
-
-template cFloatValue*(val: float): Snippet = $val
-
-proc addInt64Literal*(result: var Builder; i: BiggestInt) =
-  if i > low(int64):
-    result.add "IL64($1)" % [rope(i)]
-  else:
-    result.add "(IL64(-9223372036854775807) - IL64(1))"
-
-proc addUint64Literal*(result: var Builder; i: uint64) =
-  result.add rope($i & "ULL")
-
-proc addIntLiteral*(result: var Builder; i: BiggestInt) =
-  if i > low(int32) and i <= high(int32):
-    result.addIntValue(i)
-  elif i == low(int32):
-    # Nim has the same bug for the same reasons :-)
-    result.add "(-2147483647 -1)"
-  elif i > low(int64):
-    result.add "IL64($1)" % [rope(i)]
-  else:
-    result.add "(IL64(-9223372036854775807) - IL64(1))"
-
-proc addIntLiteral*(result: var Builder; i: Int128) =
-  addIntLiteral(result, toInt64(i))
-
-proc cInt64Literal*(i: BiggestInt): Snippet =
-  if i > low(int64):
-    result = "IL64($1)" % [rope(i)]
-  else:
-    result = "(IL64(-9223372036854775807) - IL64(1))"
-
-proc cUint64Literal*(i: uint64): Snippet =
-  result = $i & "ULL"
-
-proc cIntLiteral*(i: BiggestInt): Snippet =
-  if i > low(int32) and i <= high(int32):
-    result = rope(i)
-  elif i == low(int32):
-    # Nim has the same bug for the same reasons :-)
-    result = "(-2147483647 -1)"
-  elif i > low(int64):
-    result = "IL64($1)" % [rope(i)]
-  else:
-    result = "(IL64(-9223372036854775807) - IL64(1))"
-
-proc cIntLiteral*(i: Int128): Snippet =
-  result = cIntLiteral(toInt64(i))
-
-const
-  NimInt* = "NI"
-  NimInt8* = "NI8"
-  NimInt16* = "NI16"
-  NimInt32* = "NI32"
-  NimInt64* = "NI64"
-  CInt* = "int"
-  NimUint* = "NU"
-  NimUint8* = "NU8"
-  NimUint16* = "NU16"
-  NimUint32* = "NU32"
-  NimUint64* = "NU64"
-  NimFloat* = "NF"
-  NimFloat32* = "NF32"
-  NimFloat64* = "NF64"
-  NimFloat128* = "NF128" # not actually defined
-  NimNan* = "NAN"
-  NimInf* = "INF"
-  NimBool* = "NIM_BOOL"
-  NimTrue* = "NIM_TRUE"
-  NimFalse* = "NIM_FALSE"
-  NimChar* = "NIM_CHAR"
-  CChar* = "char"
-  NimCstring* = "NCSTRING"
-  NimNil* = "NIM_NIL"
-  CNil* = "NULL"
-  NimStrlitFlag* = "NIM_STRLIT_FLAG"
-  CVoid* = "void"
-  CPointer* = "void*"
-  CConstPointer* = "NIM_CONST void*"
-
-proc cIntType*(bits: BiggestInt): Snippet =
-  "NI" & $bits
-
-proc cUintType*(bits: BiggestInt): Snippet =
-  "NU" & $bits
-
-type
-  IfBuilderState* = enum
-    WaitingIf, WaitingElseIf, InBlock
-  IfBuilder* = object
-    state*: IfBuilderState
--- a/compiler/cbuilderdecls.nim
+++ b/compiler/cbuilderdecls.nim
@@ -1,668 +0,0 @@
-type VarKind = enum
-  Local
-  Global
-  Threadvar
-  Const
-  AlwaysConst ## const even on C++
-
-proc addVarHeader(builder: var Builder, kind: VarKind) =
-  ## adds modifiers for given var kind:
-  ## Local has no modifier
-  ## Global has `static` modifier
-  ## Const has `static NIM_CONST` modifier
-  ## AlwaysConst has `static const` modifier (NIM_CONST is no-op on C++)
-  ## Threadvar is unimplemented
-  case kind
-  of Local: discard
-  of Global:
-    builder.add("static ")
-  of Const:
-    builder.add("static NIM_CONST ")
-  of AlwaysConst:
-    builder.add("static const ")
-  of Threadvar:
-    doAssert false, "unimplemented"
-
-proc addVar(builder: var Builder, kind: VarKind = Local, name: string, typ: Snippet, initializer: Snippet = "") =
-  ## adds a variable declaration to the builder
-  builder.addVarHeader(kind)
-  builder.add(typ)
-  builder.add(" ")
-  builder.add(name)
-  if initializer.len != 0:
-    builder.add(" = ")
-    builder.add(initializer)
-  builder.addLineEnd(";")
-
-template addVarWithType(builder: var Builder, kind: VarKind = Local, name: string, body: typed) =
-  ## adds a variable declaration to the builder, with the `body` building the type
-  builder.addVarHeader(kind)
-  body
-  builder.add(" ")
-  builder.add(name)
-  builder.addLineEnd(";")
-
-template addVarWithInitializer(builder: var Builder, kind: VarKind = Local, name: string,
-                               typ: Snippet, initializerBody: typed) =
-  ## adds a variable declaration to the builder, with
-  ## `initializerBody` building the initializer. initializer must be provided
-  builder.addVarHeader(kind)
-  builder.add(typ)
-  builder.add(" ")
-  builder.add(name)
-  builder.add(" = ")
-  initializerBody
-  builder.addLineEnd(";")
-
-template addVarWithTypeAndInitializer(builder: var Builder, kind: VarKind = Local, name: string,
-                                      typeBody, initializerBody: typed) =
-  ## adds a variable declaration to the builder, with `typeBody` building the type, and
-  ## `initializerBody` building the initializer. initializer must be provided
-  builder.addVarHeader(kind)
-  typeBody
-  builder.add(" ")
-  builder.add(name)
-  builder.add(" = ")
-  initializerBody
-  builder.addLineEnd(";")
-
-proc addArrayVar(builder: var Builder, kind: VarKind = Local, name: string, elementType: Snippet, len: int, initializer: Snippet = "") =
-  ## adds an array variable declaration to the builder
-  builder.addVarHeader(kind)
-  builder.add(elementType)
-  builder.add(" ")
-  builder.add(name)
-  builder.add("[")
-  builder.addIntValue(len)
-  builder.add("]")
-  if initializer.len != 0:
-    builder.add(" = ")
-    builder.add(initializer)
-  builder.addLineEnd(";")
-
-template addArrayVarWithInitializer(builder: var Builder, kind: VarKind = Local, name: string, elementType: Snippet, len: int, body: typed) =
-  ## adds an array variable declaration to the builder with the initializer built according to `body`
-  builder.addVarHeader(kind)
-  builder.add(elementType)
-  builder.add(" ")
-  builder.add(name)
-  builder.add("[")
-  builder.addIntValue(len)
-  builder.add("] = ")
-  body
-  builder.addLineEnd(";")
-
-template addTypedef(builder: var Builder, name: string, typeBody: typed) =
-  ## adds a typedef declaration to the builder with name `name` and type as
-  ## built in `typeBody`
-  builder.add("typedef ")
-  typeBody
-  builder.add(" ")
-  builder.add(name)
-  builder.addLineEnd(";")
-
-proc addProcTypedef(builder: var Builder, callConv: TCallingConvention, name: string, rettype, params: Snippet) =
-  builder.add("typedef ")
-  builder.add(CallingConvToStr[callConv])
-  builder.add("_PTR(")
-  builder.add(rettype)
-  builder.add(", ")
-  builder.add(name)
-  builder.add(")")
-  builder.add(params)
-  builder.addLineEnd(";")
-
-template addArrayTypedef(builder: var Builder, name: string, len: BiggestInt, typeBody: typed) =
-  ## adds an array typedef declaration to the builder with name `name`,
-  ## length `len`, and element type as built in `typeBody`
-  builder.add("typedef ")
-  typeBody
-  builder.add(" ")
-  builder.add(name)
-  builder.add("[")
-  builder.addIntValue(len)
-  builder.addLineEnd("];")
-
-type
-  StructInitializerKind = enum
-    siOrderedStruct ## struct constructor, but without named fields on C
-    siNamedStruct ## struct constructor, with named fields i.e. C99 designated initializer
-    siArray ## array constructor
-    siWrapper ## wrapper for a single field, generates it verbatim
-
-  StructInitializer = object
-    ## context for building struct initializers, i.e. `{ field1, field2 }`
-    kind: StructInitializerKind
-      ## if true, fields will not be named, instead values are placed in order
-    needsComma: bool
-
-proc initStructInitializer(builder: var Builder, kind: StructInitializerKind): StructInitializer =
-  ## starts building a struct initializer, i.e. braced initializer list
-  result = StructInitializer(kind: kind, needsComma: false)
-  if kind != siWrapper:
-    builder.add("{")
-
-template addField(builder: var Builder, constr: var StructInitializer, name: string, valueBody: typed) =
-  ## adds a field to a struct initializer, with the value built in `valueBody`
-  if constr.needsComma:
-    assert constr.kind != siWrapper, "wrapper constructor cannot have multiple fields"
-    builder.add(", ")
-  else:
-    constr.needsComma = true
-  case constr.kind
-  of siArray, siWrapper:
-    # no name, can just add value
-    valueBody
-  of siOrderedStruct:
-    # positional init - name not used in output (empty allowed for anonymous unions)
-    valueBody
-  of siNamedStruct:
-    # designated init - empty name for anonymous unions (skips .name = prefix)
-    if name.len != 0:
-      builder.add(".")
-      builder.add(name)
-      builder.add(" = ")
-    valueBody
-
-proc finishStructInitializer(builder: var Builder, constr: StructInitializer) =
-  ## finishes building a struct initializer
-  if constr.kind != siWrapper:
-    builder.add("}")
-
-template addStructInitializer(builder: var Builder, constr: out StructInitializer, kind: StructInitializerKind, body: typed) =
-  ## builds a struct initializer, i.e. `{ field1, field2 }`
-  ## a `var StructInitializer` must be declared and passed as a parameter so
-  ## that it can be used with `addField`
-  constr = builder.initStructInitializer(kind)
-  body
-  builder.finishStructInitializer(constr)
-
-proc addField(obj: var Builder; name, typ: Snippet; isFlexArray: bool = false; initializer: Snippet = "") =
-  ## adds a field inside a struct/union type
-  obj.add('\t')
-  obj.add(typ)
-  obj.add(" ")
-  obj.add(name)
-  if isFlexArray:
-    obj.add("[SEQ_DECL_SIZE]")
-  if initializer.len != 0:
-    obj.add(initializer)
-  obj.add(";\n")
-
-proc addArrayField(obj: var Builder; name, elementType: Snippet; len: int; initializer: Snippet = "") =
-  ## adds an array field inside a struct/union type
-  obj.add('\t')
-  obj.add(elementType)
-  obj.add(" ")
-  obj.add(name)
-  obj.add("[")
-  obj.addIntValue(len)
-  obj.add("]")
-  if initializer.len != 0:
-    obj.add(initializer)
-  obj.add(";\n")
-
-proc addField(obj: var Builder; field: PSym; name, typ: Snippet; isFlexArray: bool = false; initializer: Snippet = "") =
-  ## adds an field inside a struct/union type, based on an `skField` symbol
-  obj.add('\t')
-  if field.alignment > 0:
-    obj.add("NIM_ALIGN(")
-    obj.addIntValue(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.addIntValue(field.bitsize)
-  if initializer.len != 0:
-    obj.add(initializer)
-  obj.add(";\n")
-
-proc addProcField(obj: var Builder, callConv: TCallingConvention, name: string, rettype, params: Snippet) =
-  obj.add(CallingConvToStr[callConv])
-  obj.add("_PTR(")
-  obj.add(rettype)
-  obj.add(", ")
-  obj.add(name)
-  obj.add(")")
-  obj.add(params)
-  obj.add(";\n")
-
-type
-  BaseClassKind = enum
-    ## denotes how and whether or not the base class/RTTI should be stored
-    bcNone, bcCppInherit, bcSupField, bcNoneRtti, bcNoneTinyRtti
-  StructBuilderInfo = object
-    ## context for building `struct` types
-    baseKind: BaseClassKind
-    named: bool
-    preFieldsLen: int
-
-proc structOrUnion(t: PType): Snippet =
-  let t = t.skipTypes({tyAlias, tySink})
-  if tfUnion in t.flags: "union"
-  else: "struct"
-
-proc startSimpleStruct(obj: var Builder; m: BModule; name: string; baseType: Snippet): StructBuilderInfo =
-  result = StructBuilderInfo(baseKind: bcNone, named: name.len != 0)
-  obj.add("struct")
-  if result.named:
-    obj.add(" ")
-    obj.add(name)
-  if baseType.len != 0:
-    if m.compileToCpp:
-      result.baseKind = bcCppInherit
-    else:
-      result.baseKind = bcSupField
-  if result.baseKind == bcCppInherit:
-    obj.add(" : public ")
-    obj.add(baseType)
-  obj.add(" ")
-  obj.add("{\n")
-  result.preFieldsLen = obj.buf.len
-  if result.baseKind == bcSupField:
-    obj.addField(name = "Sup", typ = baseType)
-
-proc finishSimpleStruct(obj: var Builder; m: BModule; info: StructBuilderInfo) =
-  if info.baseKind == bcNone and info.preFieldsLen == obj.buf.len:
-    # no fields were added, add dummy field
-    obj.addField(name = "dummy", typ = CChar)
-  if info.named:
-    obj.add("};\n")
-  else:
-    obj.add("}")
-
-template addSimpleStruct(obj: var Builder; m: BModule; name: string; baseType: Snippet; body: typed) =
-  ## builds a struct type not based on a Nim type with fields according to `body`,
-  ## `name` can be empty to build as a type expression and not a statement
-  let info = startSimpleStruct(obj, m, name, baseType)
-  body
-  finishSimpleStruct(obj, m, info)
-
-proc startStruct(obj: var Builder; m: BModule; t: PType; name: string; baseType: Snippet): StructBuilderInfo =
-  result = StructBuilderInfo(baseKind: bcNone, named: name.len != 0)
-  if tfPacked in t.flags:
-    if hasAttribute in CC[m.config.cCompiler].props:
-      obj.add(structOrUnion(t))
-      obj.add(" __attribute__((__packed__))")
-    else:
-      obj.add("#pragma pack(push, 1)\n")
-      obj.add(structOrUnion(t))
-  else:
-    obj.add(structOrUnion(t))
-  if result.named:
-    obj.add(" ")
-    obj.add(name)
-  if t.kind == tyObject:
-    if t.baseClass == nil:
-      if lacksMTypeField(t):
-        result.baseKind = bcNone
-      elif optTinyRtti in m.config.globalOptions:
-        result.baseKind = bcNoneTinyRtti
-      else:
-        result.baseKind = bcNoneRtti
-    elif m.compileToCpp:
-      result.baseKind = bcCppInherit
-    else:
-      result.baseKind = bcSupField
-  elif baseType.len != 0:
-    if m.compileToCpp:
-      result.baseKind = bcCppInherit
-    else:
-      result.baseKind = bcSupField
-  if result.baseKind == bcCppInherit:
-    obj.add(" : public ")
-    obj.add(baseType)
-  obj.add(" ")
-  obj.add("{\n")
-  result.preFieldsLen = obj.buf.len
-  case result.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 t.bindingId notin m.g.graph.memberProcsPerType and
-        t.n != nil and t.n.len == 1 and t.n[0].kind == nkSym and
-        t.n[0].sym.typ.skipTypes(abstractInst).kind == tyUncheckedArray:
-      # only consists of flexible array field, add *initial* dummy field
-      obj.addField(name = "dummy", typ = CChar)
-  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)
-
-proc finishStruct(obj: var Builder; m: BModule; t: PType; info: StructBuilderInfo) =
-  if info.baseKind == bcNone and info.preFieldsLen == obj.buf.len and
-      t.bindingId notin m.g.graph.memberProcsPerType:
-    # no fields were added, add dummy field
-    obj.addField(name = "dummy", typ = CChar)
-  if info.named:
-    obj.add("};\n")
-  else:
-    obj.add("}")
-  if tfPacked in t.flags and hasAttribute notin CC[m.config.cCompiler].props:
-    obj.add("#pragma pack(pop)\n")
-
-template addStruct(obj: var Builder; m: BModule; typ: PType; name: string; baseType: Snippet; body: typed) =
-  ## builds a struct type directly based on `typ` with fields according to `body`,
-  ## `name` can be empty to build as a type expression and not a statement
-  let info = startStruct(obj, m, typ, name, baseType)
-  body
-  finishStruct(obj, m, typ, info)
-
-template addFieldWithStructType(obj: var Builder; m: BModule; parentTyp: PType; fieldName: string, body: typed) =
-  ## adds a field with a `struct { ... }` type, building the fields 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:
-    obj.add("#pragma pack(pop)\n")
-
-template addAnonUnion(obj: var Builder; body: typed) =
-  ## adds an anonymous union i.e. `union { ... };` with fields according to `body`
-  obj.add "union{\n"
-  body
-  obj.add("};\n")
-
-template addUnionType(obj: var Builder; body: typed) =
-  ## adds a union type i.e. `union { ... }` with fields according to `body`
-  obj.add "union{\n"
-  body
-  obj.add("}")
-
-type DeclVisibility = enum
-  None
-  Extern
-  ExternC
-  ImportLib
-  ExportLib
-  ExportLibVar
-  Private
-  StaticProc
-
-proc addVisibilityPrefix(builder: var Builder, visibility: DeclVisibility) =
-  # internal proc
-  case visibility
-  of None: discard
-  of Extern:
-    builder.add("extern ")
-  of ExternC:
-    builder.add("NIM_EXTERNC ")
-  of ImportLib:
-    builder.add("N_LIB_IMPORT ")
-  of ExportLib:
-    builder.add("N_LIB_EXPORT ")
-  of ExportLibVar:
-    builder.add("N_LIB_EXPORT_VAR ")
-  of Private:
-    builder.add("N_LIB_PRIVATE ")
-  of StaticProc:
-    builder.add("static ")
-
-template addDeclWithVisibility(builder: var Builder, visibility: DeclVisibility, declBody: typed) =
-  ## adds a declaration as in `declBody` with the given visibility
-  builder.addVisibilityPrefix(visibility)
-  declBody
-
-type ProcParamBuilder = object
-  needsComma: bool
-
-proc initProcParamBuilder(builder: var Builder): ProcParamBuilder =
-  result = ProcParamBuilder(needsComma: false)
-  builder.add("(")
-
-proc finishProcParamBuilder(builder: var Builder, params: ProcParamBuilder) =
-  if params.needsComma:
-    builder.add(")")
-  else:
-    builder.add("void)")
-
-template cgDeclFrmt*(s: PSym): string =
-  s.constraint.strVal
-
-proc addParam(builder: var Builder, params: var ProcParamBuilder, name: string, typ: Snippet) =
-  if params.needsComma:
-    builder.add(", ")
-  else:
-    params.needsComma = true
-  builder.add(typ)
-  builder.add(" ")
-  builder.add(name)
-
-proc addParam(builder: var Builder, params: var ProcParamBuilder, param: PSym, typ: Snippet) =
-  if params.needsComma:
-    builder.add(", ")
-  else:
-    params.needsComma = true
-  var modifiedTyp = typ
-  if sfNoalias in param.flags:
-    modifiedTyp.add(" NIM_NOALIAS")
-  if sfCodegenDecl notin param.flags:
-    builder.add(modifiedTyp)
-    builder.add(" ")
-    builder.add(param.loc.snippet)
-  else:
-    builder.add runtimeFormat(param.cgDeclFrmt, [modifiedTyp, param.loc.snippet])
-
-proc addUnnamedParam(builder: var Builder, params: var ProcParamBuilder, typ: Snippet) =
-  if params.needsComma:
-    builder.add(", ")
-  else:
-    params.needsComma = true
-  builder.add(typ)
-
-proc addProcTypedParam(builder: var Builder, paramBuilder: var ProcParamBuilder, callConv: TCallingConvention, name: string, rettype, params: Snippet) =
-  if paramBuilder.needsComma:
-    builder.add(", ")
-  else:
-    paramBuilder.needsComma = true
-  builder.add(CallingConvToStr[callConv])
-  builder.add("_PTR(")
-  builder.add(rettype)
-  builder.add(", ")
-  builder.add(name)
-  builder.add(")")
-  builder.add(params)
-
-proc addVarargsParam(builder: var Builder, params: var ProcParamBuilder) =
-  # does not exist in NIFC, needs to be proc pragma
-  if params.needsComma:
-    builder.add(", ")
-  else:
-    params.needsComma = true
-  builder.add("...")
-
-template addProcParams(builder: var Builder, params: out ProcParamBuilder, body: typed) =
-  params = initProcParamBuilder(builder)
-  body
-  finishProcParamBuilder(builder, params)
-
-type SimpleProcParam = tuple
-  name, typ: string
-
-proc cProcParams(params: varargs[SimpleProcParam]): Snippet =
-  if params.len == 0: return "(void)"
-  result = "("
-  for i in 0 ..< params.len:
-    if i != 0: result.add(", ")
-    result.add(params[i].typ)
-    if params[i].name.len != 0:
-      result.add(" ")
-      result.add(params[i].name)
-  result.add(")")
-
-template addProcHeaderWithParams(builder: var Builder, callConv: TCallingConvention,
-                                 name: string, rettype: Snippet, paramBuilder: typed) =
-  # on nifc should build something like (proc name params type pragmas
-  # with no body given
-  # or enforce this with secondary builder object
-  builder.add(CallingConvToStr[callConv])
-  builder.add("(")
-  builder.add(rettype)
-  builder.add(", ")
-  builder.add(name)
-  builder.add(")")
-  paramBuilder
-
-proc addProcHeader(builder: var Builder, callConv: TCallingConvention,
-                   name: string, rettype, params: Snippet) =
-  # on nifc should build something like (proc name params type pragmas
-  # with no body given
-  # or enforce this with secondary builder object
-  addProcHeaderWithParams(builder, callConv, name, rettype):
-    builder.add(params)
-
-proc addProcHeader(builder: var Builder, name: string, rettype, params: Snippet, isConstructor = false) =
-  # no callconv
-  builder.add(rettype)
-  builder.add(" ")
-  if isConstructor:
-    builder.add("__attribute__((constructor)) ")
-  builder.add(name)
-  builder.add(params)
-
-proc addProcHeader(builder: var Builder, m: BModule, prc: PSym, name: string, params, rettype: Snippet, addAttributes: bool) =
-  # on nifc should build something like (proc name params type pragmas
-  # with no body given
-  # or enforce this with secondary builder object
-  let noreturn = isNoReturn(m, prc)
-  if sfPure in prc.flags and hasDeclspec in extccomp.CC[m.config.cCompiler].props:
-    builder.add("__declspec(naked) ")
-  if noreturn and hasDeclspec in extccomp.CC[m.config.cCompiler].props:
-    builder.add("__declspec(noreturn) ")
-  builder.add(CallingConvToStr[prc.typ.callConv])
-  builder.add("(")
-  builder.add(rettype)
-  builder.add(", ")
-  builder.add(name)
-  builder.add(")")
-  builder.add(params)
-  if addAttributes:
-    if sfPure in prc.flags and hasAttribute in extccomp.CC[m.config.cCompiler].props:
-      builder.add(" __attribute__((naked))")
-    if noreturn and hasAttribute in extccomp.CC[m.config.cCompiler].props:
-      builder.add(" __attribute__((noreturn))")
-
-proc finishProcHeaderAsProto(builder: var Builder) =
-  builder.addLineEnd(";")
-
-template finishProcHeaderWithBody(builder: var Builder, body: typed) =
-  builder.addLineEndIndent(" {")
-  body
-  builder.addLineEndDedent("}")
-  builder.addNewline
-
-proc addProcVar(builder: var Builder, m: BModule, prc: PSym, name: string, params, rettype: Snippet,
-                isStatic = false, ignoreAttributes = false) =
-  # on nifc, builds full variable
-  if isStatic:
-    builder.add("static ")
-  let noreturn = isNoReturn(m, prc)
-  if not ignoreAttributes:
-    if sfPure in prc.flags and hasDeclspec in extccomp.CC[m.config.cCompiler].props:
-      builder.add("__declspec(naked) ")
-    if noreturn and hasDeclspec in extccomp.CC[m.config.cCompiler].props:
-      builder.add("__declspec(noreturn) ")
-  builder.add(CallingConvToStr[prc.typ.callConv])
-  builder.add("_PTR(")
-  builder.add(rettype)
-  builder.add(", ")
-  builder.add(name)
-  builder.add(")")
-  builder.add(params)
-  if not ignoreAttributes:
-    if sfPure in prc.flags and hasAttribute in extccomp.CC[m.config.cCompiler].props:
-      builder.add(" __attribute__((naked))")
-    if noreturn and hasAttribute in extccomp.CC[m.config.cCompiler].props:
-      builder.add(" __attribute__((noreturn))")
-  # ensure we are just adding a variable:
-  builder.addLineEnd(";")
-
-proc addProcVar(builder: var Builder, callConv: TCallingConvention,
-                name: string, params, rettype: Snippet,
-                isStatic = false, isVolatile = false) =
-  # on nifc, builds full variable
-  if isStatic:
-    builder.add("static ")
-  builder.add(CallingConvToStr[callConv])
-  builder.add("_PTR(")
-  builder.add(rettype)
-  builder.add(", ")
-  if isVolatile:
-    builder.add("volatile ")
-  builder.add(name)
-  builder.add(")")
-  builder.add(params)
-  # ensure we are just adding a variable:
-  builder.addLineEnd(";")
-
-proc addProcVar(builder: var Builder,
-                name: string, params, rettype: Snippet,
-                isStatic = false, isVolatile = false) =
-  # no callconv
-  if isStatic:
-    builder.add("static ")
-  builder.add(rettype)
-  builder.add(" (*")
-  if isVolatile:
-    builder.add("volatile ")
-  builder.add(name)
-  builder.add(")")
-  builder.add(params)
-  # ensure we are just adding a variable:
-  builder.addLineEnd(";")
-
-type VarInitializerKind = enum
-  Assignment, CppConstructor
-
-proc addVar(builder: var Builder, m: BModule, s: PSym, name: string, typ: Snippet, kind = Local, visibility: DeclVisibility = None, initializer: Snippet = "", initializerKind: VarInitializerKind = Assignment) =
-  if sfCodegenDecl in s.flags:
-    builder.add(runtimeFormat(s.cgDeclFrmt, [typ, name]))
-    if initializer.len != 0:
-      if initializerKind == Assignment:
-        builder.add(" = ")
-      builder.add(initializer)
-    builder.addLineEnd(";")
-    return
-  if s.kind in {skLet, skVar, skField, skForVar} and s.alignment > 0:
-    builder.add("NIM_ALIGN(" & $s.alignment & ") ")
-  builder.addVisibilityPrefix(visibility)
-  if kind == Threadvar:
-    if optThreads in m.config.globalOptions:
-      let sym = s.typ.sym
-      if sym != nil and sfCppNonPod in sym.flags:
-        builder.add("NIM_THREAD_LOCAL ")
-      else: builder.add("NIM_THREADVAR ")
-  else:
-    builder.addVarHeader(kind)
-  builder.add(typ)
-  if sfRegister in s.flags: builder.add(" register")
-  if sfVolatile in s.flags: builder.add(" volatile")
-  if sfNoalias in s.flags: builder.add(" NIM_NOALIAS")
-  builder.add(" ")
-  builder.add(name)
-  if initializer.len != 0:
-    if initializerKind == Assignment:
-      builder.add(" = ")
-    builder.add(initializer)
-  builder.addLineEnd(";")
-
-proc addInclude(builder: var Builder, value: Snippet) =
-  builder.addLineEnd("#include " & value)
--- a/compiler/cbuilderexprs.nim
+++ b/compiler/cbuilderexprs.nim
@@ -1,259 +0,0 @@
-proc constType(t: Snippet): Snippet =
-  # needs manipulation of `t` in nifc
-  "NIM_CONST " & t
-
-proc constPtrType(t: Snippet): Snippet =
-  t & "* NIM_CONST"
-
-proc ptrConstType(t: Snippet): Snippet =
-  "NIM_CONST " & t & "*"
-
-proc ptrType(t: Snippet): Snippet =
-  t & "*"
-
-proc cppRefType(t: Snippet): Snippet =
-  t & "&"
-
-const
-  CallingConvToStr: array[TCallingConvention, string] = ["N_NIMCALL",
-    "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
-    ]
-
-proc procPtrTypeUnnamed(rettype, params: Snippet): Snippet =
-  rettype & "(*)" & params
-
-proc procPtrTypeUnnamedNimCall(rettype, params: Snippet): Snippet =
-  rettype & "(N_RAW_NIMCALL*)" & params
-
-proc procPtrTypeUnnamed(callConv: TCallingConvention, rettype, params: Snippet): Snippet =
-  CallingConvToStr[callConv] & "_PTR(" & rettype & ", )" & params
-
-type CppCaptureKind = enum None, ByReference, ByCopy
-
-template addCppLambda(builder: var Builder, captures: CppCaptureKind, params: Snippet, body: typed) =
-  builder.add("[")
-  case captures
-  of None: discard
-  of ByReference: builder.add("&")
-  of ByCopy: builder.add("=")
-  builder.add("] ")
-  builder.add(params)
-  builder.addLineEndIndent(" {")
-  body
-  builder.addLineEndDedent("}")
-
-proc cCast(typ, value: Snippet): Snippet =
-  "((" & typ & ") " & value & ")"
-
-proc wrapPar(value: Snippet): Snippet =
-  # used for expression group, no-op on sexp
-  "(" & value & ")"
-
-proc removeSinglePar(value: Snippet): Snippet =
-  # removes a single paren layer expected to exist, to silence Wparentheses-equality
-  assert value[0] == '(' and value[^1] == ')'
-  value[1..^2]
-
-template addCast(builder: var Builder, typ: Snippet, valueBody: typed) =
-  ## adds a cast to `typ` with value built by `valueBody`
-  builder.add "(("
-  builder.add typ
-  builder.add ") "
-  valueBody
-  builder.add ")"
-
-proc cAddr(value: Snippet): Snippet =
-  "(&" & value & ")"
-
-proc cLabelAddr(value: TLabel): Snippet =
-  "&&" & value
-
-proc cDeref(value: Snippet): Snippet =
-  "(*" & value & ")"
-
-proc subscript(a, b: Snippet): Snippet =
-  a & "[" & b & "]"
-
-proc dotField(a, b: Snippet): Snippet =
-  a & "." & b
-
-proc derefField(a, b: Snippet): Snippet =
-  a & "->" & b
-
-type CallBuilder = object
-  needsComma: bool
-
-proc initCallBuilder(builder: var Builder, callee: Snippet): CallBuilder =
-  result = CallBuilder(needsComma: false)
-  builder.add(callee)
-  builder.add("(")
-
-const cArgumentSeparator = ", "
-
-proc addArgumentSeparator(builder: var Builder) =
-  # no-op on NIFC
-  # used by "single argument" builders
-  builder.add(cArgumentSeparator)
-
-template addArgument(builder: var Builder, call: var CallBuilder, valueBody: typed) =
-  if call.needsComma:
-    builder.addArgumentSeparator()
-  else:
-    call.needsComma = true
-  valueBody
-
-proc finishCallBuilder(builder: var Builder, call: CallBuilder) =
-  builder.add(")")
-
-template addCall(builder: var Builder, call: out CallBuilder, callee: Snippet, body: typed) =
-  call = initCallBuilder(builder, callee)
-  body
-  finishCallBuilder(builder, call)
-
-proc addCall(builder: var Builder, callee: Snippet, args: varargs[Snippet]) =
-  builder.add(callee)
-  builder.add("(")
-  if args.len != 0:
-    builder.add(args[0])
-    for i in 1 ..< args.len:
-      builder.add(", ")
-      builder.add(args[i])
-  builder.add(")")
-
-proc cCall(callee: Snippet, args: varargs[Snippet]): Snippet =
-  result = callee
-  result.add("(")
-  if args.len != 0:
-    result.add(args[0])
-    for i in 1 ..< args.len:
-      result.add(", ")
-      result.add(args[i])
-  result.add(")")
-
-proc addSizeof(builder: var Builder, val: Snippet) =
-  builder.add("sizeof(")
-  builder.add(val)
-  builder.add(")")
-
-proc addAlignof(builder: var Builder, val: Snippet) =
-  builder.add("NIM_ALIGNOF(")
-  builder.add(val)
-  builder.add(")")
-
-proc addOffsetof(builder: var Builder, val, member: Snippet) =
-  builder.add("offsetof(")
-  builder.add(val)
-  builder.add(", ")
-  builder.add(member)
-  builder.add(")")
-
-template cSizeof(val: Snippet): Snippet =
-  "sizeof(" & val & ")"
-
-template cAlignof(val: Snippet): Snippet =
-  "NIM_ALIGNOF(" & val & ")"
-
-template cOffsetof(val, member: Snippet): Snippet =
-  "offsetof(" & val & ", " & member & ")"
-
-type TypedBinaryOp = enum
-  Add, Sub, Mul, Div, Mod
-  Shr, Shl, BitAnd, BitOr, BitXor
-
-const typedBinaryOperators: array[TypedBinaryOp, string] = [
-  Add: "+",
-  Sub: "-",
-  Mul: "*",
-  Div: "/",
-  Mod: "%",
-  Shr: ">>",
-  Shl: "<<",
-  BitAnd: "&",
-  BitOr: "|",
-  BitXor: "^"
-]
-
-type TypedUnaryOp = enum
-  Neg, BitNot
-
-const typedUnaryOperators: array[TypedUnaryOp, string] = [
-  Neg: "-",
-  BitNot: "~",
-]
-
-type UntypedBinaryOp = enum
-  LessEqual, LessThan, GreaterEqual, GreaterThan, Equal, NotEqual
-  And, Or
-
-const untypedBinaryOperators: array[UntypedBinaryOp, string] = [
-  LessEqual: "<=",
-  LessThan: "<",
-  GreaterEqual: ">=",
-  GreaterThan: ">",
-  Equal: "==",
-  NotEqual: "!=",
-  And: "&&",
-  Or: "||"
-]
-
-type UntypedUnaryOp = enum
-  Not
-
-const untypedUnaryOperators: array[UntypedUnaryOp, string] = [
-  Not: "!"
-]
-
-proc addOp(builder: var Builder, binOp: TypedBinaryOp, t: Snippet, a, b: Snippet) =
-  builder.add('(')
-  builder.add(a)
-  builder.add(' ')
-  builder.add(typedBinaryOperators[binOp])
-  builder.add(' ')
-  builder.add(b)
-  builder.add(')')
-
-proc addOp(builder: var Builder, unOp: TypedUnaryOp, t: Snippet, a: Snippet) =
-  builder.add('(')
-  builder.add(typedUnaryOperators[unOp])
-  builder.add('(')
-  builder.add(a)
-  builder.add("))")
-
-proc addOp(builder: var Builder, binOp: UntypedBinaryOp, a, b: Snippet) =
-  builder.add('(')
-  builder.add(a)
-  builder.add(' ')
-  builder.add(untypedBinaryOperators[binOp])
-  builder.add(' ')
-  builder.add(b)
-  builder.add(')')
-
-proc addOp(builder: var Builder, unOp: UntypedUnaryOp, a: Snippet) =
-  builder.add('(')
-  builder.add(untypedUnaryOperators[unOp])
-  builder.add('(')
-  builder.add(a)
-  builder.add("))")
-
-template cOp(binOp: TypedBinaryOp, t: Snippet, a, b: Snippet): Snippet =
-  '(' & a & ' ' & typedBinaryOperators[binOp] & ' ' & b & ')'
-
-template cOp(binOp: TypedUnaryOp, t: Snippet, a: Snippet): Snippet =
-  '(' & typedUnaryOperators[binOp] & '(' & a & "))"
-
-template cOp(binOp: UntypedBinaryOp, a, b: Snippet): Snippet =
-  '(' & a & ' ' & untypedBinaryOperators[binOp] & ' ' & b & ')'
-
-template cOp(binOp: UntypedUnaryOp, a: Snippet): Snippet =
-  '(' & untypedUnaryOperators[binOp] & '(' & a & "))"
-
-template cIfExpr(cond, a, b: Snippet): Snippet =
-  # XXX used for `min` and `max`, maybe add nifc primitives for these
-  "(" & cond & " ? " & a & " : " & b & ")"
-
-template cUnlikely(val: Snippet): Snippet =
-  "NIM_UNLIKELY(" & val & ")"
--- a/compiler/cbuilderstmts.nim
+++ b/compiler/cbuilderstmts.nim
@@ -1,329 +0,0 @@
-template addAssignmentWithValue(builder: var Builder, lhs: Snippet, valueBody: typed) =
-  builder.add(lhs)
-  builder.add(" = ")
-  valueBody
-  builder.addLineEnd(";")
-
-template addFieldAssignmentWithValue(builder: var Builder, lhs: Snippet, name: string, valueBody: typed) =
-  builder.add(lhs)
-  builder.add("." & name & " = ")
-  valueBody
-  builder.addLineEnd(";")
-
-template addAssignment(builder: var Builder, lhs, rhs: Snippet) =
-  builder.addAssignmentWithValue(lhs):
-    builder.add(rhs)
-
-template addFieldAssignment(builder: var Builder, lhs: Snippet, name: string, rhs: Snippet) =
-  builder.addFieldAssignmentWithValue(lhs, name):
-    builder.add(rhs)
-
-template addMutualFieldAssignment(builder: var Builder, lhs, rhs: Snippet, name: string) =
-  builder.addFieldAssignmentWithValue(lhs, name):
-    builder.add(rhs)
-    builder.add("." & name)
-
-template addAssignment(builder: var Builder, lhs: Snippet, rhs: int | int64 | uint64 | Int128) =
-  builder.addAssignmentWithValue(lhs):
-    builder.addIntValue(rhs)
-
-template addFieldAssignment(builder: var Builder, lhs: Snippet, name: string, rhs: int | int64 | uint64 | Int128) =
-  builder.addFieldAssignmentWithValue(lhs, name):
-    builder.addIntValue(rhs)
-
-template addDerefFieldAssignment(builder: var Builder, lhs: Snippet, name: string, rhs: Snippet) =
-  builder.add(lhs)
-  builder.add("->" & name & " = ")
-  builder.add(rhs)
-  builder.addLineEnd(";")
-
-template addSubscriptAssignment(builder: var Builder, lhs: Snippet, index: Snippet, rhs: Snippet) =
-  builder.add(lhs)
-  builder.add("[" & index & "] = ")
-  builder.add(rhs)
-  builder.addLineEnd(";")
-
-template addStmt(builder: var Builder, stmtBody: typed) =
-  ## makes an expression built by `stmtBody` into a statement
-  stmtBody
-  builder.addLineEnd(";")
-
-proc addCallStmt(builder: var Builder, callee: Snippet, args: varargs[Snippet]) =
-  builder.addStmt():
-    builder.addCall(callee, args)
-
-# XXX blocks need indent tracker in `Builder` object
-
-template addSingleIfStmt(builder: var Builder, cond: Snippet, body: typed) =
-  builder.add("if (")
-  builder.add(cond)
-  builder.addLineEndIndent(") {")
-  body
-  builder.addLineEndDedent("}")
-
-template addSingleIfStmtWithCond(builder: var Builder, condBody: typed, body: typed) =
-  builder.add("if (")
-  condBody
-  builder.addLineEndIndent(") {")
-  body
-  builder.addLineEndDedent("}")
-
-proc initIfStmt(builder: var Builder): IfBuilder =
-  IfBuilder(state: WaitingIf)
-
-proc finishIfStmt(builder: var Builder, stmt: IfBuilder) =
-  assert stmt.state != InBlock
-  builder.addNewline()
-
-template addIfStmt(builder: var Builder, stmt: out IfBuilder, body: typed) =
-  stmt = initIfStmt(builder)
-  body
-  finishIfStmt(builder, stmt)
-
-proc initElifBranch(builder: var Builder, stmt: var IfBuilder, cond: Snippet) =
-  case stmt.state
-  of WaitingIf:
-    builder.add("if (")
-  of WaitingElseIf:
-    builder.add(" else if (")
-  else: assert false, $stmt.state
-  builder.add(cond)
-  builder.addLineEndIndent(") {")
-  stmt.state = InBlock
-
-proc initElseBranch(builder: var Builder, stmt: var IfBuilder) =
-  assert stmt.state == WaitingElseIf, $stmt.state
-  builder.addLineEndIndent(" else {")
-  stmt.state = InBlock
-
-proc finishBranch(builder: var Builder, stmt: var IfBuilder) =
-  builder.addDedent("}")
-  stmt.state = WaitingElseIf
-
-template addElifBranch(builder: var Builder, stmt: var IfBuilder, cond: Snippet, body: typed) =
-  initElifBranch(builder, stmt, cond)
-  body
-  finishBranch(builder, stmt)
-
-template addElseBranch(builder: var Builder, stmt: var IfBuilder, body: typed) =
-  initElseBranch(builder, stmt)
-  body
-  finishBranch(builder, stmt)
-
-proc initForRange(builder: var Builder, i, start, bound: Snippet, inclusive: bool = false) =
-  builder.add("for (")
-  builder.add(i)
-  builder.add(" = ")
-  builder.add(start)
-  builder.add("; ")
-  builder.add(i)
-  if inclusive:
-    builder.add(" <= ")
-  else:
-    builder.add(" < ")
-  builder.add(bound)
-  builder.add("; ")
-  builder.add(i)
-  builder.addLineEndIndent("++) {")
-
-proc initForStep(builder: var Builder, i, start, bound, step: Snippet, inclusive: bool = false) =
-  builder.add("for (")
-  builder.add(i)
-  builder.add(" = ")
-  builder.add(start)
-  builder.add("; ")
-  builder.add(i)
-  if inclusive:
-    builder.add(" <= ")
-  else:
-    builder.add(" < ")
-  builder.add(bound)
-  builder.add("; ")
-  builder.add(i)
-  builder.add(" += ")
-  builder.add(step)
-  builder.addLineEndIndent(") {")
-
-proc finishFor(builder: var Builder) {.inline.} =
-  builder.addLineEndDedent("}")
-
-template addForRangeExclusive(builder: var Builder, i, start, bound: Snippet, body: typed) =
-  initForRange(builder, i, start, bound, false)
-  body
-  finishFor(builder)
-
-template addForRangeInclusive(builder: var Builder, i, start, bound: Snippet, body: typed) =
-  initForRange(builder, i, start, bound, true)
-  body
-  finishFor(builder)
-
-template addSwitchStmt(builder: var Builder, val: Snippet, body: typed) =
-  builder.add("switch (")
-  builder.add(val)
-  builder.addLineEnd(") {") # no indent
-  body
-  builder.addLineEnd("}")
-
-template addSingleSwitchCase(builder: var Builder, val: Snippet, body: typed) =
-  builder.add("case ")
-  builder.add(val)
-  builder.addLineEndIndent(":")
-  body
-  builder.addLineEndDedent("")
-
-type
-  SwitchCaseState = enum
-    None, Of, Else, Finished
-  SwitchCaseBuilder = object
-    state: SwitchCaseState
-
-proc addCase(builder: var Builder, info: var SwitchCaseBuilder, val: Snippet) =
-  if info.state != Of:
-    assert info.state == None
-    info.state = Of
-  builder.add("case ")
-  builder.add(val)
-  builder.addLineEndIndent(":")
-
-proc addCaseRange(builder: var Builder, info: var SwitchCaseBuilder, first, last: Snippet) =
-  if info.state != Of:
-    assert info.state == None
-    info.state = Of
-  builder.add("case ")
-  builder.add(first)
-  builder.add(" ... ")
-  builder.add(last)
-  builder.addLineEndIndent(":")
-
-proc addCaseElse(builder: var Builder, info: var SwitchCaseBuilder) =
-  assert info.state == None
-  info.state = Else
-  builder.addLineEndIndent("default:")
-
-template addSwitchCase(builder: var Builder, info: out SwitchCaseBuilder, caseBody, body: typed) =
-  info = SwitchCaseBuilder(state: None)
-  caseBody
-  info.state = Finished
-  body
-  builder.addLineEndDedent("")
-
-template addSwitchElse(builder: var Builder, body: typed) =
-  builder.addLineEndIndent("default:")
-  body
-  builder.addLineEndDedent("")
-
-proc addBreak(builder: var Builder) =
-  builder.addLineEnd("break;")
-
-type ScopeBuilder = object
-  inside: bool
-
-proc initScope(builder: var Builder): ScopeBuilder =
-  builder.addLineEndIndent("{")
-  result = ScopeBuilder(inside: true)
-
-proc finishScope(builder: var Builder, scope: var ScopeBuilder) =
-  assert scope.inside, "scope not inited"
-  builder.addLineEndDedent("}")
-  scope.inside = false
-
-template addScope(builder: var Builder, body: typed) =
-  builder.addLineEndIndent("{")
-  body
-  builder.addLineEndDedent("}")
-
-type WhileBuilder = object
-  inside: bool
-
-proc initWhileStmt(builder: var Builder, cond: Snippet): WhileBuilder =
-  builder.add("while (")
-  builder.add(cond)
-  builder.addLineEndIndent(") {")
-  result = WhileBuilder(inside: true)
-
-proc finishWhileStmt(builder: var Builder, stmt: var WhileBuilder) =
-  assert stmt.inside, "while stmt not inited"
-  builder.addLineEndDedent("}")
-  stmt.inside = false
-
-template addWhileStmt(builder: var Builder, cond: Snippet, body: typed) =
-  builder.add("while (")
-  builder.add(cond)
-  builder.addLineEndIndent(") {")
-  body
-  builder.addLineEndDedent("}")
-
-proc addLabel(builder: var Builder, name: TLabel) =
-  builder.add(name)
-  builder.addLineEnd(": ;")
-
-proc addReturn(builder: var Builder) =
-  builder.addLineEnd("return;")
-
-proc addReturn(builder: var Builder, value: Snippet) =
-  builder.add("return ")
-  builder.add(value)
-  builder.addLineEnd(";")
-
-proc addGoto(builder: var Builder, label: TLabel) =
-  builder.add("goto ")
-  builder.add(label)
-  builder.addLineEnd(";")
-
-proc addComputedGoto(builder: var Builder, value: Snippet) =
-  builder.add("goto *")
-  builder.add(value)
-  builder.addLineEnd(";")
-
-proc addIncr(builder: var Builder, val: Snippet) =
-  builder.add(val)
-  builder.addLineEnd("++;")
-
-proc addDecr(builder: var Builder, val: Snippet) =
-  builder.add(val)
-  builder.addLineEnd("--;")
-
-proc addInPlaceOp(builder: var Builder, binOp: TypedBinaryOp, t: Snippet, a, b: Snippet) =
-  builder.add(a)
-  builder.add(' ')
-  builder.add(typedBinaryOperators[binOp])
-  builder.add("= ")
-  builder.add(b)
-  builder.addLineEnd(";")
-
-proc addInPlaceOp(builder: var Builder, binOp: UntypedBinaryOp, a, b: Snippet) =
-  builder.add(a)
-  builder.add(' ')
-  builder.add(untypedBinaryOperators[binOp])
-  builder.add("= ")
-  builder.add(b)
-  builder.addLineEnd(";")
-
-proc cInPlaceOp(binOp: TypedBinaryOp, t: Snippet, a, b: Snippet): Snippet =
-  result = ""
-  result.add(a)
-  result.add(' ')
-  result.add(typedBinaryOperators[binOp])
-  result.add("= ")
-  result.add(b)
-  result.add(";\n")
-
-proc cInPlaceOp(binOp: UntypedBinaryOp, a, b: Snippet): Snippet =
-  result = ""
-  result.add(a)
-  result.add(' ')
-  result.add(untypedBinaryOperators[binOp])
-  result.add("= ")
-  result.add(b)
-  result.add(";\n")
-
-template addCPragma(builder: var Builder, val: Snippet) =
-  builder.addNewline()
-  builder.add("#pragma ")
-  builder.add(val)
-  builder.addNewline()
-
-proc addDiscard(builder: var Builder, val: Snippet) =
-  builder.add("(void)")
-  builder.add(val)
-  builder.addLineEnd(";")
--- a/compiler/ccgcalls.nim
+++ b/compiler/ccgcalls.nim
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
--- a/compiler/ccgliterals.nim
+++ b/compiler/ccgliterals.nim
@@ -16,17 +16,19 @@
 ## implementation.

 template detectVersion(field, corename) =
-  if m.g.config.selectedGC in {gcArc, gcOrc, gcYrc, gcAtomicArc, gcHooks}:
-    result = 2
-  else:
-    result = 1
+  if m.g.field == 0:
+    let core = getCompilerProc(m.g.graph, corename)
+    if core == nil or core.kind != skConst:
+      m.g.field = 1
+    else:
+      m.g.field = toInt(ast.getInt(core.astdef))
+  result = m.g.field

 proc detectStrVersion(m: BModule): int =
-  if m.g.config.usesSso() and
-      m.g.config.selectedGC in {gcArc, gcOrc, gcYrc, gcAtomicArc, gcHooks}:
-    result = 3
-  else:
-    detectVersion(strVersion, "nimStrVersion")
+  detectVersion(strVersion, "nimStrVersion")
+
+proc detectSeqVersion(m: BModule): int =
+  detectVersion(seqVersion, "nimSeqVersion")

 # ----- Version 1: GC'ed strings and seqs --------------------------------

@@ -34,85 +36,53 @@ proc genStringLiteralDataOnlyV1(m: BModule, s: string; result: var Rope) =
  cgsym(m, "TGenericSeq")
  let tmp = getTempName(m)
  result.add tmp
-  var res = newBuilder("")
-  res.addVarWithTypeAndInitializer(AlwaysConst, name = tmp):
-    res.addSimpleStruct(m, name = "", baseType = ""):
-      res.addField(name = "Sup", typ = "TGenericSeq")
-      res.addArrayField(name = "data", elementType = NimChar, len = s.len + 1)
-  do:
-    var strInit: StructInitializer
-    res.addStructInitializer(strInit, kind = siOrderedStruct):
-      res.addField(strInit, name = "Sup"):
-        var seqInit: StructInitializer
-        res.addStructInitializer(seqInit, kind = siOrderedStruct):
-          res.addField(seqInit, name = "len"):
-            res.addIntValue(s.len)
-          res.addField(seqInit, name = "reserved"):
-            res.add(cCast(NimInt, cOp(BitOr, NimUint, cCast(NimUint, cIntValue(s.len)), NimStrlitFlag)))
-      res.addField(strInit, name = "data"):
-        res.add(makeCString(s))
-  m.s[cfsStrData].add(extract(res))
+  m.s[cfsStrData].addf("STRING_LITERAL($1, $2, $3);$n",
+       [tmp, makeCString(s), rope(s.len)])

-proc genStringLiteralV1(m: BModule; n: AnyNode; result: var Builder) =
+proc genStringLiteralV1(m: BModule; n: PNode; result: var Rope) =
  if s.isNil:
-    result.add(cCast(ptrType(cgsymValue(m, "NimStringDesc")), NimNil))
+    appcg(m, result, "((#NimStringDesc*) NIM_NIL)", [])
  else:
-    let id = nodeTableTestOrSet(m.dataCache, origin(n), m.labels)
-    var name: string = ""
+    let id = nodeTableTestOrSet(m.dataCache, n, m.labels)
    if id == m.labels:
      # string literal not found in the cache:
-      genStringLiteralDataOnlyV1(m, n.strVal, name)
+      appcg(m, result, "((#NimStringDesc*) &", [])
+      genStringLiteralDataOnlyV1(m, n.strVal, result)
+      result.add ")"
    else:
-      name = m.tmpBase & $id
-    result.add(cCast(ptrType(cgsymValue(m, "NimStringDesc")), cAddr(name)))
+      appcg(m, result, "((#NimStringDesc*) &$1$2)",
+                      [m.tmpBase, id])

 # ------ Version 2: destructor based strings and seqs -----------------------

 proc genStringLiteralDataOnlyV2(m: BModule, s: string; result: Rope; isConst: bool) =
-  var res = newBuilder("")
-  res.addVarWithTypeAndInitializer(
-      if isConst: AlwaysConst else: Global,
-      name = result):
-    res.addSimpleStruct(m, name = "", baseType = ""):
-      res.addField(name = "cap", typ = NimInt)
-      res.addArrayField(name = "data", elementType = NimChar, len = s.len + 1)
-  do:
-    var structInit: StructInitializer
-    res.addStructInitializer(structInit, kind = siOrderedStruct):
-      res.addField(structInit, name = "cap"):
-        res.add(cOp(BitOr, NimInt, cIntValue(s.len), NimStrlitFlag))
-      res.addField(structInit, name = "data"):
-        res.add(makeCString(s))
-  m.s[cfsStrData].add(extract(res))
+  m.s[cfsStrData].addf("static $4 struct {$n" &
+       "  NI cap; NIM_CHAR data[$2+1];$n" &
+       "} $1 = { $2 | NIM_STRLIT_FLAG, $3 };$n",
+       [result, rope(s.len), makeCString(s),
+       rope(if isConst: "const" else: "")])

-proc genStringLiteralV2(m: BModule; n: AnyNode; isConst: bool; result: var Builder) =
-  let id = nodeTableTestOrSet(m.dataCache, origin(n), m.labels)
-  var litName: string
+proc genStringLiteralV2(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)
+    genStringLiteralDataOnlyV2(m, n.strVal, pureLit, isConst)
+    let tmp = getTempName(m)
+    result.add tmp
    cgsym(m, "NimStrPayload")
    cgsym(m, "NimStringV2")
    # string literal not found in the cache:
-    litName = getTempName(m)
-    genStringLiteralDataOnlyV2(m, n.strVal, litName, isConst)
+    m.s[cfsStrData].addf("static $4 NimStringV2 $1 = {$2, (NimStrPayload*)&$3};$n",
+          [tmp, rope(n.strVal.len), pureLit, rope(if isConst: "const" else: "")])
  else:
-    litName = m.tmpBase & $id
-  let tmp = getTempName(m)
-  result.add tmp
-  var res = newBuilder("")
-  res.addVarWithInitializer(
-      if isConst: AlwaysConst else: Global,
-      name = tmp,
-      typ = "NimStringV2"):
-    var strInit: StructInitializer
-    res.addStructInitializer(strInit, kind = siOrderedStruct):
-      res.addField(strInit, name = "len"):
-        res.addIntValue(n.strVal.len)
-      res.addField(strInit, name = "p"):
-        res.add(cCast(ptrType("NimStrPayload"), cAddr(litName)))
-  m.s[cfsStrData].add(extract(res))
+    let tmp = getTempName(m)
+    result.add tmp
+    m.s[cfsStrData].addf("static $4 NimStringV2 $1 = {$2, (NimStrPayload*)&$3};$n",
+          [tmp, rope(n.strVal.len), m.tmpBase & rope(id),
+          rope(if isConst: "const" else: "")])

-proc genStringLiteralV2Const(m: BModule; n: AnyNode; isConst: bool; result: var Builder) =
-  let id = nodeTableTestOrSet(m.dataCache, origin(n), m.labels)
+proc genStringLiteralV2Const(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)
@@ -122,189 +92,27 @@ proc genStringLiteralV2Const(m: BModule; n: AnyNode; isConst: bool; result: var
    genStringLiteralDataOnlyV2(m, n.strVal, pureLit, isConst)
  else:
    pureLit = m.tmpBase & rope(id)
-  var strInit: StructInitializer
-  result.addStructInitializer(strInit, kind = siOrderedStruct):
-    result.addField(strInit, name = "len"):
-      result.addIntValue(n.strVal.len)
-    result.addField(strInit, name = "p"):
-      result.add(cCast(ptrType("NimStrPayload"), cAddr(pureLit)))
-
-proc ssoBytesLit(m: BModule; s: string; slen: int): string =
-  ## Compute the `bytes` field value for the new SmallString layout.
-  ## byte 0 = slen, bytes 1-7 = inline chars 0-6 (zero-padded).
-  ## On LE: slen in bits 0-7, char[i] in bits (i+1)*8..(i+1)*8+7.
-  ## On BE: slen in bits 56-63, char[i] in bits (6-i)*8..(6-i)*8+7.
-  const AlwaysAvail = 7
-  var val: uint64
-  if CPU[m.g.config.target.targetCPU].endian == littleEndian:
-    val = uint64(slen)
-    for i in 0..<min(s.len, AlwaysAvail):
-      val = val or (uint64(s[i]) shl (uint(i + 1) * 8))
-  else:
-    val = uint64(slen) shl 56
-    for i in 0..<min(s.len, AlwaysAvail):
-      val = val or (uint64(s[i]) shl (uint(AlwaysAvail - 1 - i) * 8))
-  # Cast to NU (C name for Nim's uint, = NU64 on 64-bit). NU64 = uint64_t.
-  result = cCast("NU", $val & "ULL")
-
-proc ssoMoreLit(m: BModule; s: string): string =
-  ## For medium string literals (AlwaysAvail < len <= PayloadSize), encode
-  ## chars[AlwaysAvail..ptrSize-1] in the 'more' pointer field bit-pattern.
-  ## The last pointer byte is always '\0' (null terminator), guaranteed by
-  ## PayloadSize = AlwaysAvail + ptrSize - 1.  slen <= PayloadSize guards
-  ## prevent any code from dereferencing this as an actual pointer.
-  const AlwaysAvail = 7
-  let ptrSize = m.g.config.target.ptrSize
-  var val: uint64 = 0
-  for i in 0..<ptrSize:
-    let ch: uint64 = if AlwaysAvail + i < s.len: uint64(s[AlwaysAvail + i]) else: 0
-    if CPU[m.g.config.target.targetCPU].endian == littleEndian:
-      val = val or (ch shl (uint(i) * 8))
-    else:
-      val = val or (ch shl (uint(ptrSize - 1 - i) * 8))
-  result = cCast(ptrType("LongString"), "(uintptr_t)" & $val)
-
-proc genStringLiteralV3Const(m: BModule; n: AnyNode; isConst: bool; result: var Builder) =
-  # Inline SmallString struct initializer for use inside const aggregate types.
-  # Layout: {bytes: NimUint, more: ptr LongString}
-  # bytes = slen (low byte) | char[0]<<8 | char[1]<<16 | ... | char[6]<<56
-  const AlwaysAvail = 7
-  let s = n.strVal
-
-  cgsym(m, "SmallString")
-  cgsym(m, "LongString")
-
-  let payloadSize = AlwaysAvail + m.g.config.target.ptrSize - 1
-  var si: StructInitializer
-  result.addStructInitializer(si, kind = siOrderedStruct):
-    if s.len <= AlwaysAvail:
-      result.addField(si, name = "bytes"):
-        result.add(ssoBytesLit(m, s, s.len))
-      result.addField(si, name = "more"):
-        result.add(NimNil)
-    elif s.len <= payloadSize:
-      # Medium string: bytes holds slen + chars 0-6; more holds chars 7..PayloadSize-1.
-      result.addField(si, name = "bytes"):
-        result.add(ssoBytesLit(m, s, s.len))
-      result.addField(si, name = "more"):
-        result.add(ssoMoreLit(m, s))
-    else:
-      # Emit the LongString block into cfsStrData and reference it inline.
-      let dataName = getTempName(m)
-      var res = newBuilder("")
-      res.addVarWithTypeAndInitializer(
-          if isConst: AlwaysConst else: Global,
-          name = dataName):
-        res.addSimpleStruct(m, name = "", baseType = ""):
-          res.addField(name = "rc", typ = NimInt)
-          res.addField(name = "fullLen", typ = NimInt)
-          res.addField(name = "capImpl", typ = NimInt)
-          res.addArrayField(name = "data", elementType = NimChar, len = s.len + 1)
-      do:
-        var di: StructInitializer
-        res.addStructInitializer(di, kind = siOrderedStruct):
-          res.addField(di, name = "fullLen"):
-            res.addIntValue(s.len)
-          res.addField(di, name = "rc"):
-            res.addIntValue(1)
-          res.addField(di, name = "capImpl"):
-            res.addIntValue(0)  # static, never freed
-          res.addField(di, name = "data"):
-            res.add(makeCString(s))
-      m.s[cfsStrData].add(extract(res))
-      # slen = StaticSlen (254): marks this as a static (never-freed) long string.
-      result.addField(si, name = "bytes"):
-        result.add(ssoBytesLit(m, s, 254))
-      result.addField(si, name = "more"):
-        result.add(cCast(ptrType("LongString"), cAddr(dataName)))
-
-# ------ Version 3: SmallString (SSO) strings --------------------------------
-
-proc genStringLiteralV3(m: BModule; n: AnyNode; isConst: bool; result: var Builder) =
-  # SmallString literal. Always generate a fresh SmallString variable (like v2
-  # always generates a fresh outer NimStringV2). For long strings, cache the
-  # LongString payload to avoid duplicates within a module.
-  const AlwaysAvail = 7  # must match strs_v3.nim
-  let s = n.strVal
-  let tmp = getTempName(m)
-  result.add tmp
-
-  cgsym(m, "SmallString")
-  cgsym(m, "LongString")
-
-  let payloadSize = AlwaysAvail + m.g.config.target.ptrSize - 1
-  var res = newBuilder("")
-  if s.len <= AlwaysAvail:
-    # Short: bytes holds slen + all chars (zero-padded), more = NULL.
-    res.addVarWithInitializer(
-        if isConst: AlwaysConst else: Global,
-        name = tmp, typ = "SmallString"):
-      var si: StructInitializer
-      res.addStructInitializer(si, kind = siOrderedStruct):
-        res.addField(si, name = "bytes"):
-          res.add(ssoBytesLit(m, s, s.len))
-        res.addField(si, name = "more"):
-          res.add(NimNil)
-  elif s.len <= payloadSize:
-    # Medium: bytes holds slen + chars 0-6; more holds chars 7..PayloadSize-1 as raw bits.
-    res.addVarWithInitializer(
-        if isConst: AlwaysConst else: Global,
-        name = tmp, typ = "SmallString"):
-      var si: StructInitializer
-      res.addStructInitializer(si, kind = siOrderedStruct):
-        res.addField(si, name = "bytes"):
-          res.add(ssoBytesLit(m, s, s.len))
-        res.addField(si, name = "more"):
-          res.add(ssoMoreLit(m, s))
-  else:
-    # Long: cache the LongString block to emit it only once per module per string.
-    # Always generate a fresh SmallString pointing at the (possibly cached) block.
-    let id = nodeTableTestOrSet(m.dataCache, origin(n), m.labels)
-    var dataName: string
-    if id == m.labels:
-      dataName = getTempName(m)
-      res.addVarWithTypeAndInitializer(
-          if isConst: AlwaysConst else: Global,
-          name = dataName):
-        res.addSimpleStruct(m, name = "", baseType = ""):
-          res.addField(name = "rc", typ = NimInt)
-          res.addField(name = "fullLen", typ = NimInt)
-          res.addField(name = "capImpl", typ = NimInt)
-          res.addArrayField(name = "data", elementType = NimChar, len = s.len + 1)
-      do:
-        var di: StructInitializer
-        res.addStructInitializer(di, kind = siOrderedStruct):
-          res.addField(di, name = "fullLen"):
-            res.addIntValue(s.len)
-          res.addField(di, name = "rc"):
-            res.addIntValue(1)
-          res.addField(di, name = "capImpl"):
-            res.addIntValue(0)  # bit 0 = 0: static, never freed
-          res.addField(di, name = "data"):
-            res.add(makeCString(s))
-    else:
-      dataName = m.tmpBase & $id
-    # slen = StaticSlen (254): marks this as a static (never-freed) long string.
-    res.addVarWithInitializer(
-        if isConst: AlwaysConst else: Global,
-        name = tmp, typ = "SmallString"):
-      var si: StructInitializer
-      res.addStructInitializer(si, kind = siOrderedStruct):
-        res.addField(si, name = "bytes"):
-          res.add(ssoBytesLit(m, s, 254))
-        res.addField(si, name = "more"):
-          res.add(cCast(ptrType("LongString"), cAddr(dataName)))
-  m.s[cfsStrData].add(extract(res))
+  result.addf "{$1, (NimStrPayload*)&$2}", [rope(n.strVal.len), pureLit]

 # ------ Version selector ---------------------------------------------------

-proc genNilStringLiteral(m: BModule; info: TLineInfo; result: var Builder) =
-  result.add(cCast(ptrType(cgsymValue(m, "NimStringDesc")), NimNil))
+proc genStringLiteralDataOnly(m: BModule; s: string; info: TLineInfo;
+                              isConst: bool; result: var Rope) =
+  case detectStrVersion(m)
+  of 0, 1: genStringLiteralDataOnlyV1(m, s, result)
+  of 2:
+    let tmp = getTempName(m)
+    genStringLiteralDataOnlyV2(m, s, tmp, isConst)
+    result.add tmp
+  else:
+    localError(m.config, info, "cannot determine how to produce code for string literal")

-proc genStringLiteral(m: BModule; n: AnyNode; result: var Builder) =
+proc genNilStringLiteral(m: BModule; info: TLineInfo; result: var Rope) =
+  appcg(m, result, "((#NimStringDesc*) NIM_NIL)", [])
+
+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
@@ -19,35 +19,33 @@ proc specializeResetN(p: BProc, accessor: Rope, n: PNode;
  if n == nil: return
  case n.kind
  of nkRecList:
-    for it in sons(n):
-      specializeResetN(p, accessor, it, typ)
+    for i in 0..<n.len:
+      specializeResetN(p, accessor, n[i], typ)
  of nkRecCase:
-    if (n.firstSon.kind != nkSym): internalError(p.config, n.info, "specializeResetN")
-    let disc = n.firstSon.sym
-    if disc.loc.snippet == "": fillObjectFields(p.module, typ)
+    if (n[0].kind != nkSym): internalError(p.config, n.info, "specializeResetN")
+    let disc = n[0].sym
+    if disc.loc.r == "": fillObjectFields(p.module, typ)
    if disc.loc.t == nil:
      internalError(p.config, n.info, "specializeResetN()")
-    let discField = dotField(accessor, disc.loc.snippet)
-    p.s(cpsStmts).addSwitchStmt(discField):
-      for branch in sonsFrom(n, 1):
-        assert branch.kind in {nkOfBranch, nkElse}
-        var caseBuilder: SwitchCaseBuilder
-        p.s(cpsStmts).addSwitchCase(caseBuilder):
-          if branch.kind == nkOfBranch:
-            genCaseRange(p, branch, caseBuilder)
-          else:
-            p.s(cpsStmts).addCaseElse(caseBuilder)
-        do:
-          specializeResetN(p, accessor, lastSon(branch), typ)
-          p.s(cpsStmts).addBreak()
-    specializeResetT(p, discField, disc.loc.t)
+    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}
+      if branch.kind == nkOfBranch:
+        genCaseRange(p, branch)
+      else:
+        lineF(p, cpsStmts, "default:$n", [])
+      specializeResetN(p, accessor, lastSon(branch), typ)
+      lineF(p, cpsStmts, "break;$n", [])
+    lineF(p, cpsStmts, "} $n", [])
+    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, dotField(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) =
@@ -60,73 +58,45 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
  of tyArray:
    let arraySize = lengthOrd(p.config, typ.indexType)
    var i: TLoc = getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt))
-    p.s(cpsStmts).addForRangeExclusive(i.snippet, cIntValue(0), cIntValue(arraySize)):
-      specializeResetT(p, subscript(accessor, i.snippet), typ.elementType)
+    linefmt(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
+            [i.r, arraySize])
+    specializeResetT(p, ropecg(p.module, "$1[$2]", [accessor, i.r]), typ.elementType)
+    lineF(p, cpsStmts, "}$n", [])
  of tyObject:
    var x = typ.baseClass
    if x != nil: x = x.skipTypes(skipPtrs)
    specializeResetT(p, accessor.parentObj(p.module), x)
-    if typ.n != nil:
-      if typ.sym != nil and sfImportc in typ.sym.flags:
-        # imported C struct, nimZeroMem
-        p.s(cpsStmts).addCallStmt(cgsymValue(p.module, "nimZeroMem"),
-          cCast(ptrType(CPointer), cAddr(accessor)),
-          cSizeof(getTypeDesc(p.module, typ)))
-      else:
-        specializeResetN(p, accessor, typ.n, typ)
-        if isCaseObj(typ.n):
-          # The active branch was released above. Clear the complete object so
-          # stale bytes from overlapping branches cannot be traced by the GC.
-          # type
-          #   Foo = object
-          #     case kind: bool
-          #     of true:
-          #       a: ref Bar   # 8 bytes (pointer)
-          #     of false:
-          #       b: int       # 4 bytes
-          # specializeResetT for b emits accessor.b = 0 — writes 4 bytes
-          # But the union is 8 bytes wide (sized by the largest branch)
-          # The remaining 4 bytes where a used to live are untouched
-          # Those stale bytes could contain a heap pointer the GC traces → crash
-          p.s(cpsStmts).addCallStmt(cgsymValue(p.module, "nimZeroMem"),
-            cCast(CPointer, cAddr(accessor)),
-            cSizeof(getTypeDesc(p.module, typ)))
+    if typ.n != nil: specializeResetN(p, accessor, typ.n, typ)
  of tyTuple:
    let typ = getUniqueType(typ)
    for i, a in typ.ikids:
-      specializeResetT(p, dotField(accessor, "Field" & $i), a)
+      specializeResetT(p, ropecg(p.module, "$1.Field$2", [accessor, i]), a)

  of tyString, tyRef, tySequence:
-    p.s(cpsStmts).addCallStmt(cgsymValue(p.module, "unsureAsgnRef"),
-      cCast(ptrType(CPointer), cAddr(accessor)),
-      NimNil)
+    lineCg(p, cpsStmts, "#unsureAsgnRef((void**)&$1, NIM_NIL);$n", [accessor])

  of tyProc:
    if typ.callConv == ccClosure:
-      p.s(cpsStmts).addCallStmt(cgsymValue(p.module, "unsureAsgnRef"),
-        cCast(ptrType(CPointer), cAddr(dotField(accessor, "ClE_0"))),
-        NimNil)
-      p.s(cpsStmts).addFieldAssignment(accessor, "ClP_0", NimNil)
+      lineCg(p, cpsStmts, "#unsureAsgnRef((void**)&$1.ClE_0, NIM_NIL);$n", [accessor])
+      lineCg(p, cpsStmts, "$1.ClP_0 = NIM_NIL;$n", [accessor])
    else:
-      p.s(cpsStmts).addAssignment(accessor, NimNil)
+      lineCg(p, cpsStmts, "$1 = NIM_NIL;$n", [accessor])
  of tyChar, tyBool, tyEnum, tyRange, tyInt..tyUInt64:
-    p.s(cpsStmts).addAssignment(accessor, cIntValue(0))
+    lineCg(p, cpsStmts, "$1 = 0;$n", [accessor])
  of tyCstring, tyPointer, tyPtr, tyVar, tyLent:
-    p.s(cpsStmts).addAssignment(accessor, NimNil)
+    lineCg(p, cpsStmts, "$1 = NIM_NIL;$n", [accessor])
  of tySet:
    case mapSetType(p.config, typ)
    of ctArray:
-      let t = getTypeDesc(p.module, typ)
-      p.s(cpsStmts).addCallStmt(cgsymValue(p.module, "nimZeroMem"),
-        accessor,
-        cSizeof(t))
+      lineCg(p, cpsStmts, "#nimZeroMem($1, sizeof($2));$n",
+          [accessor, getTypeDesc(p.module, typ)])
    of ctInt8, ctInt16, ctInt32, ctInt64:
-      p.s(cpsStmts).addAssignment(accessor, cIntValue(0))
+      lineCg(p, cpsStmts, "$1 = 0;$n", [accessor])
    else:
      raiseAssert "unexpected set type kind"
  of tyNone, tyEmpty, tyNil, tyUntyped, tyTyped, tyGenericInvocation,
      tyGenericParam, tyOrdinal, tyOpenArray, tyForward, tyVarargs,
-      tyUncheckedArray, tyError, tyBuiltInTypeClass, tyUserTypeClass,
+      tyUncheckedArray, tyProxy, tyBuiltInTypeClass, tyUserTypeClass,
      tyUserTypeClassInst, tyCompositeTypeClass, tyAnd, tyOr, tyNot,
      tyAnything, tyStatic, tyFromExpr, tyConcept, tyVoid, tyIterable:
    discard
--- a/compiler/ccgstmts.nim
+++ b/compiler/ccgstmts.nim
--- a/compiler/ccgthreadvars.nim
+++ b/compiler/ccgthreadvars.nim
@@ -19,12 +19,9 @@ proc accessThreadLocalVar(p: BProc, s: PSym) =
  if emulatedThreadVars(p.config) and threadVarAccessed notin p.flags:
    p.flags.incl threadVarAccessed
    incl p.module.flags, usesThreadVars
-    p.procSec(cpsLocals).addVar(kind = Local,
-      name = "NimTV_",
-      typ = ptrType("NimThreadVars"))
-    p.procSec(cpsInit).addAssignment("NimTV_",
-      cCast(ptrType("NimThreadVars"),
-        cCall(cgsymValue(p.module, "GetThreadLocalVars"))))
+    p.procSec(cpsLocals).addf("\tNimThreadVars* NimTV_;$n", [])
+    p.procSec(cpsInit).add(
+      ropecg(p.module, "\tNimTV_ = (NimThreadVars*) #GetThreadLocalVars();$n", []))

 proc declareThreadVar(m: BModule, s: PSym, isExtern: bool) =
  if emulatedThreadVars(m.config):
@@ -33,51 +30,30 @@ 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.addField(name = s.loc.snippet, typ = getTypeDesc(m, s.loc.t))
+      m.g.nimtv.addf("$1 $2;$n", [getTypeDesc(m, s.loc.t), s.loc.r])
  else:
-    let vis =
-      if isExtern: Extern
-      elif lfExportLib in s.loc.flags: ExportLibVar
-      else: Private
-    if m.config.cmd == cmdNifC and vis == Private and not isExtern:
-      # A `{.threadvar.}`/`{.global.}` thread-local declared inside a routine is
-      # emitted by every module that emit-everywhere's its enclosing routine
-      # (e.g. libp2p's `var keys {.global.}: HashSet`), so its content-addressed
-      # name collides at link. Same fix as a plain global (genGlobalVarDecl):
-      # `extern` declaration + a droppable `'d'` definition unit the merge stage
-      # assigns one owner. The thread-local storage class rides on both.
-      let cname = stripCnifMarks(s.loc.snippet)
-      let td = getTypeDesc(m, s.loc.t)
-      # `extern` declaration via the full `addVar` overload — it knows the
-      # thread-local storage class (`NIM_THREADVAR`); the simple `addVar`'s
-      # `addVarHeader` does not implement `Threadvar`.
-      m.s[cfsVars].addVar(m, s, name = s.loc.snippet, typ = td,
-                          kind = Threadvar, visibility = Extern)
-      m.s[cfsVars].add(cnifDefDirective(cname, "d", icNifName(m, s)))
-      m.s[cfsVars].addVar(m, s,
-        name = s.loc.snippet, typ = td, kind = Threadvar, visibility = vis)
-      m.s[cfsVars].add(cnifEndDefs())
-    else:
-      m.s[cfsVars].addVar(m, s,
-        name = s.loc.snippet,
-        typ = getTypeDesc(m, s.loc.t),
-        kind = Threadvar,
-        visibility = vis)
+    if isExtern: m.s[cfsVars].add("extern ")
+    elif lfExportLib in s.loc.flags: m.s[cfsVars].add("N_LIB_EXPORT_VAR ")
+    else: m.s[cfsVars].add("N_LIB_PRIVATE ")
+    if optThreads in m.config.globalOptions:
+      let sym = s.typ.sym
+      if sym != nil and sfCppNonPod in sym.flags:
+        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.r])

 proc generateThreadLocalStorage(m: BModule) =
-  if m.g.nimtv.buf.len != 0 and (usesThreadVars in m.flags or sfMainModule in m.module.flags):
+  if m.g.nimtv != "" and (usesThreadVars in m.flags or sfMainModule in m.module.flags):
    for t in items(m.g.nimtvDeps): discard getTypeDesc(m, t)
    finishTypeDescriptions(m)
-    m.s[cfsSeqTypes].addTypedef(name = "NimThreadVars"):
-      m.s[cfsSeqTypes].addSimpleStruct(m, name = "", baseType = ""):
-        m.s[cfsSeqTypes].add(extract(m.g.nimtv))
+    m.s[cfsSeqTypes].addf("typedef struct {$1} NimThreadVars;$n", [m.g.nimtv])

 proc generateThreadVarsSize(m: BModule) =
-  if m.g.nimtv.buf.len != 0:
+  if m.g.nimtv != "":
    let externc = if m.config.backend == backendCpp or
-                       sfCompileToCpp in m.module.flags: ExternC
-                  else: None
-    m.s[cfsProcs].addDeclWithVisibility(externc):
-      m.s[cfsProcs].addProcHeader("NimThreadVarsSize", NimInt, cProcParams())
-      m.s[cfsProcs].finishProcHeaderWithBody():
-        m.s[cfsProcs].addReturn(cCast(NimInt, cSizeof("NimThreadVars")))
+                       sfCompileToCpp in m.module.flags: "extern \"C\" "
+                  else: ""
+    m.s[cfsProcs].addf(
+      "$#NI NimThreadVarsSize(){return (NI)sizeof(NimThreadVars);}$n",
+      [externc.rope])
--- a/compiler/ccgtrav.nim
+++ b/compiler/ccgtrav.nim
@@ -16,55 +16,50 @@ type
    p: BProc
    visitorFrmt: string

+const
+  visitorFrmt = "#nimGCvisit((void*)$1, $2);$n"

 proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType)
-proc genCaseRange(p: BProc, branch: AnyNode, info: var SwitchCaseBuilder)
+proc genCaseRange(p: BProc, branch: PNode)
 proc getTemp(p: BProc, t: PType, needsInit=false): TLoc

-proc visit(p: BProc, data, visitor: Snippet) =
-  p.s(cpsStmts).addCallStmt(cgsymValue(p.module, "nimGCvisit"),
-    cCast(CPointer, data),
-    visitor)
-
 proc genTraverseProc(c: TTraversalClosure, accessor: Rope, n: PNode;
                     typ: PType) =
  if n == nil: return
  case n.kind
  of nkRecList:
-    for it in sons(n):
-      genTraverseProc(c, accessor, it, typ)
+    for i in 0..<n.len:
+      genTraverseProc(c, accessor, n[i], typ)
  of nkRecCase:
-    if (n.firstSon.kind != nkSym): internalError(c.p.config, n.info, "genTraverseProc")
+    if (n[0].kind != nkSym): internalError(c.p.config, n.info, "genTraverseProc")
    var p = c.p
-    let disc = n.firstSon.sym
-    if disc.loc.snippet == "": fillObjectFields(c.p.module, typ)
+    let disc = n[0].sym
+    if disc.loc.r == "": fillObjectFields(c.p.module, typ)
    if disc.loc.t == nil:
      internalError(c.p.config, n.info, "genTraverseProc()")
-    let discField = dotField(accessor, disc.loc.snippet)
-    p.s(cpsStmts).addSwitchStmt(discField):
-      for branch in sonsFrom(n, 1):
-        assert branch.kind in {nkOfBranch, nkElse}
-        var caseBuilder: SwitchCaseBuilder
-        p.s(cpsStmts).addSwitchCase(caseBuilder):
-          if branch.kind == nkOfBranch:
-            genCaseRange(c.p, branch, caseBuilder)
-          else:
-            p.s(cpsStmts).addCaseElse(caseBuilder)
-        do:
-          genTraverseProc(c, accessor, lastSon(branch), typ)
-          p.s(cpsStmts).addBreak()
+    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}
+      if branch.kind == nkOfBranch:
+        genCaseRange(c.p, branch)
+      else:
+        lineF(p, cpsStmts, "default:$n", [])
+      genTraverseProc(c, accessor, lastSon(branch), typ)
+      lineF(p, cpsStmts, "break;$n", [])
+    lineF(p, cpsStmts, "} $n", [])
  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, dotField(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.} =
  if not m.compileToCpp:
-    result = dotField(accessor, "Sup")
+    result = "$1.Sup" % [accessor]
  else:
    result = accessor

@@ -81,14 +76,16 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType) =
    let arraySize = lengthOrd(c.p.config, typ.indexType)
    var i: TLoc = getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt))
    var oldCode = p.s(cpsStmts)
-    var oldLen, newLen: int
-    p.s(cpsStmts).addForRangeExclusive(i.snippet, cIntValue(0), cIntValue(arraySize)):
-      oldLen = p.s(cpsStmts).buf.len
-      genTraverseProc(c, subscript(accessor, i.snippet), typ.elementType)
-      newLen = p.s(cpsStmts).buf.len
-    if oldLen == newLen:
+    freeze oldCode
+    linefmt(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
+            [i.r, arraySize])
+    let oldLen = p.s(cpsStmts).len
+    genTraverseProc(c, ropecg(c.p.module, "$1[$2]", [accessor, i.r]), typ.elementType)
+    if p.s(cpsStmts).len == oldLen:
      # do not emit dummy long loops for faster debug builds:
      p.s(cpsStmts) = oldCode
+    else:
+      lineF(p, cpsStmts, "}$n", [])
  of tyObject:
    var x = typ.baseClass
    if x != nil: x = x.skipTypes(skipPtrs)
@@ -97,25 +94,23 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType) =
  of tyTuple:
    let typ = getUniqueType(typ)
    for i, a in typ.ikids:
-      genTraverseProc(c, dotField(accessor, "Field" & $i), a)
+      genTraverseProc(c, ropecg(c.p.module, "$1.Field$2", [accessor, i]), a)
  of tyRef:
-    visit(p, accessor, c.visitorFrmt)
+    lineCg(p, cpsStmts, visitorFrmt, [accessor, c.visitorFrmt])
  of tySequence:
    if optSeqDestructors notin c.p.module.config.globalOptions:
-      visit(p, accessor, c.visitorFrmt)
+      lineCg(p, cpsStmts, visitorFrmt, [accessor, c.visitorFrmt])
    elif containsGarbageCollectedRef(typ.elementType):
      # destructor based seqs are themselves not traced but their data is, if
      # they contain a GC'ed type:
-      p.s(cpsStmts).addCallStmt(cgsymValue(p.module, "nimGCvisitSeq"),
-        cCast(CPointer, accessor),
-        c.visitorFrmt)
+      lineCg(p, cpsStmts, "#nimGCvisitSeq((void*)$1, $2);$n", [accessor, c.visitorFrmt])
      #genTraverseProcSeq(c, accessor, typ)
  of tyString:
    if tfHasAsgn notin typ.flags:
-      visit(p, accessor, c.visitorFrmt)
+      lineCg(p, cpsStmts, visitorFrmt, [accessor, c.visitorFrmt])
  of tyProc:
    if typ.callConv == ccClosure:
-      visit(p, dotField(accessor, "ClE_0"), c.visitorFrmt)
+      lineCg(p, cpsStmts, visitorFrmt, [ropecg(c.p.module, "$1.ClE_0", [accessor]), c.visitorFrmt])
  else:
    discard

@@ -124,17 +119,18 @@ proc genTraverseProcSeq(c: TTraversalClosure, accessor: Rope, typ: PType) =
  assert typ.kind == tySequence
  var i = getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt))
  var oldCode = p.s(cpsStmts)
-  var oldLen, newLen: int
-  var a = TLoc(snippet: accessor)
-  let le = lenExpr(c.p, a)
+  freeze oldCode
+  var a = TLoc(r: accessor)

-  p.s(cpsStmts).addForRangeExclusive(i.snippet, cIntValue(0), le):
-    oldLen = p.s(cpsStmts).buf.len
-    genTraverseProc(c, subscript(dataField(c.p, accessor), i.snippet), typ.elementType)
-    newLen = p.s(cpsStmts).buf.len
-  if newLen == oldLen:
+  lineF(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
+      [i.r, lenExpr(c.p, a)])
+  let oldLen = p.s(cpsStmts).len
+  genTraverseProc(c, "$1$3[$2]" % [accessor, i.r, dataField(c.p)], typ.elementType)
+  if p.s(cpsStmts).len == oldLen:
    # do not emit dummy long loops for faster debug builds:
    p.s(cpsStmts) = oldCode
+  else:
+    lineF(p, cpsStmts, "}$n", [])

 proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
  var p = newProc(nil, m)
@@ -143,10 +139,11 @@ proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
    hcrOn = m.hcrOn
    typ = origTyp.skipTypes(abstractInstOwned)
    markerName = if hcrOn: result & "_actual" else: result
+    header = "static N_NIMCALL(void, $1)(void* p, NI op)" % [markerName]
    t = getTypeDesc(m, typ)

-  p.s(cpsLocals).addVar(kind = Local, name = "a", typ = t)
-  p.s(cpsInit).addAssignment("a", cCast(t, "p"))
+  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"
@@ -160,40 +157,18 @@ proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
      # C's arrays are broken beyond repair:
      genTraverseProc(c, "a".rope, typ.elementType)
    else:
-      genTraverseProc(c, cDeref("a"), typ.elementType)
+      genTraverseProc(c, "(*a)".rope, typ.elementType)

-  var headerBuilder = newBuilder("")
-  headerBuilder.addProcHeaderWithParams(ccNimCall, markerName, CVoid):
-    var paramBuilder: ProcParamBuilder
-    headerBuilder.addProcParams(paramBuilder):
-      headerBuilder.addParam(paramBuilder, name = "p", typ = CPointer)
-      headerBuilder.addParam(paramBuilder, name = "op", typ = NimInt)
-  let header = extract(headerBuilder)
+  let generatedProc = "$1 {$n$2$3$4}\n" %
+        [header, p.s(cpsLocals), p.s(cpsInit), p.s(cpsStmts)]

-  m.s[cfsProcHeaders].addDeclWithVisibility(StaticProc):
-    m.s[cfsProcHeaders].add(header)
-    m.s[cfsProcHeaders].finishProcHeaderAsProto()
-  m.s[cfsProcs].addDeclWithVisibility(StaticProc):
-    m.s[cfsProcs].add(header)
-    m.s[cfsProcs].finishProcHeaderWithBody():
-      m.s[cfsProcs].add(extract(p.s(cpsLocals)))
-      m.s[cfsProcs].add(extract(p.s(cpsInit)))
-      m.s[cfsProcs].add(extract(p.s(cpsStmts)))
+  m.s[cfsProcHeaders].addf("$1;\n", [header])
+  m.s[cfsProcs].add(generatedProc)

  if hcrOn:
-    var desc = newBuilder("")
-    var unnamedParamBuilder: ProcParamBuilder
-    desc.addProcParams(unnamedParamBuilder):
-      desc.addUnnamedParam(unnamedParamBuilder, CPointer)
-      desc.addUnnamedParam(unnamedParamBuilder, NimInt)
-    let unnamedParams = extract(desc)
-    m.s[cfsProcHeaders].addProcVar(ccNimCall, result, unnamedParams, CVoid)
-    m.s[cfsDynLibInit].addAssignmentWithValue(result):
-      m.s[cfsDynLibInit].addCast(procPtrTypeUnnamed(ccNimCall, CVoid, unnamedParams)):
-        m.s[cfsDynLibInit].addCall("hcrRegisterProc",
-          getModuleDllPath(m),
-          '"' & result & '"',
-          cCast(CPointer, markerName))
+    m.s[cfsProcHeaders].addf("N_NIMCALL_PTR(void, $1)(void*, NI);\n", [result])
+    m.s[cfsDynLibInit].addf("\t$1 = (N_NIMCALL_PTR(void, )(void*, NI)) hcrRegisterProc($3, \"$1\", (void*)$2);\n",
+         [result, markerName, getModuleDllPath(m)])

 proc genTraverseProcForGlobal(m: BModule, s: PSym; info: TLineInfo): Rope =
  discard genTypeInfoV1(m, s.loc.t, info)
@@ -204,28 +179,17 @@ proc genTraverseProcForGlobal(m: BModule, s: PSym; info: TLineInfo): Rope =

  if sfThread in s.flags and emulatedThreadVars(m.config):
    accessThreadLocalVar(p, s)
-    sLoc = derefField("NimTV_", sLoc)
+    sLoc = "NimTV_->" & sLoc

  var c = TTraversalClosure(p: p,
-    visitorFrmt: cIntValue(0) # "#nimGCvisit((void*)$1, 0);$n"
+    visitorFrmt: "0" # "#nimGCvisit((void*)$1, 0);$n"
  )

+  let header = "static N_NIMCALL(void, $1)(void)" % [result]
  genTraverseProc(c, sLoc, s.loc.t)

-  var headerBuilder = newBuilder("")
-  headerBuilder.addProcHeaderWithParams(ccNimCall, result, CVoid):
-    var paramBuilder: ProcParamBuilder
-    headerBuilder.addProcParams(paramBuilder):
-      # (void)
-      discard
-  let header = extract(headerBuilder)
+  let generatedProc = "$1 {$n$2$3$4}$n" %
+        [header, p.s(cpsLocals), p.s(cpsInit), p.s(cpsStmts)]

-  m.s[cfsProcHeaders].addDeclWithVisibility(StaticProc):
-    m.s[cfsProcHeaders].add(header)
-    m.s[cfsProcHeaders].finishProcHeaderAsProto()
-  m.s[cfsProcs].addDeclWithVisibility(StaticProc):
-    m.s[cfsProcs].add(header)
-    m.s[cfsProcs].finishProcHeaderWithBody():
-      m.s[cfsProcs].add(extract(p.s(cpsLocals)))
-      m.s[cfsProcs].add(extract(p.s(cpsInit)))
-      m.s[cfsProcs].add(extract(p.s(cpsStmts)))
+  m.s[cfsProcHeaders].addf("$1;$n", [header])
+  m.s[cfsProcs].add(generatedProc)
--- a/compiler/ccgtypes.nim
+++ b/compiler/ccgtypes.nim
--- a/compiler/ccgutils.nim
+++ b/compiler/ccgutils.nim
@@ -11,7 +11,7 @@

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

 import std/[hashes, strutils, formatfloat]

@@ -22,38 +22,18 @@ proc getPragmaStmt*(n: PNode, w: TSpecialWord): PNode =
  case n.kind
  of nkStmtList:
    result = nil
-    for it in sons(n):
-      result = getPragmaStmt(it, w)
+    for i in 0..<n.len:
+      result = getPragmaStmt(n[i], w)
      if result != nil: break
  of nkPragma:
    result = nil
-    for it in sons(n):
-      if whichPragma(it) == w: return it
+    for i in 0..<n.len:
+      if whichPragma(n[i]) == w: return n[i]
  else:
    result = nil

-proc stmtsContainPragma*(n: AnyNode, w: TSpecialWord): bool =
-  ## Deliberately NOT `getPragmaStmt(n, w) != nil`, and the reason is the one
-  ## shape the `AnyNode` seam cannot serve: a proc that returns a node OR nil.
-  ## `.bif` spells a missing child as a `DotToken` *inside* a tree, so there is
-  ## no nil token to hand back as a return value, and a `Cursor` is not nilable.
-  ## Predicates split out from such a proc are the way across.
-  ##
-  ## The duplicated traversal is the cost, and it is checked rather than
-  ## trusted: `grindPredicates` asserts this answers exactly
-  ## `getPragmaStmt(n, w) != nil` at every node, so the two cannot drift apart
-  ## silently.
-  case n.kind
-  of nkStmtList:
-    result = false
-    for it in sons(n):
-      if stmtsContainPragma(it, w): return true
-  of nkPragma:
-    result = false
-    for it in sons(n):
-      if whichPragma(it) == w: return true
-  else:
-    result = false
+proc stmtsContainPragma*(n: PNode, w: TSpecialWord): bool =
+  result = getPragmaStmt(n, w) != nil

 proc hashString*(conf: ConfigRef; s: string): BiggestInt =
  # has to be the same algorithm as strmantle.hashString!
@@ -110,9 +90,12 @@ 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.baseClass == nil):
+    elif (tfFinal in pt.flags) and (pt[0] == nil):
      result = false          # no need, because no subtyping possible
    else:
      result = true           # ordinary objects are always passed by reference,
@@ -132,35 +115,19 @@ proc encodeName*(name: string): string =

 proc makeUnique(m: BModule; s: PSym, name: string = ""): string =
  result = if name == "": s.name.s else: name
-  # keep backend-minted ids out of the `_u` namespace; their item counter
-  # restarts at 0 and would collide with loaded symbols' ids. Which integer
-  # identifies such a symbol is decided ONCE, in `astdef.backendMintedDisamb`,
-  # shared with `mangleProcNameExt` and `ast2nif.toNifSymName`.
-  if s.itemId.isBackendMinted:
-    result.add "_c"
-    result.add $backendMintedDisamb(s)
-  else:
-    result.add "_u"
-    # Mirror `mangleProcNameExt`: use the per-(module,name) `disamb`, NOT
-    # `itemId.item`. Under the per-module IC backend the same symbol is loaded
-    # from a NIF in many processes and `itemId.item` is a fresh, load-order
-    # dependent counter — so a method base would mangle to `_u1` in one module,
-    # `_u3` in another and clean at its owner, none of which link. `disamb` is
-    # assigned deterministically per (module, name) and is serialized, so every
-    # process that touches the symbol derives the identical C name.
-    result.add $s.disamb
-  # module suffix LAST (a strippable trailing token; see `mangleProcNameExt`)
  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 =
+proc encodeSym*(m: BModule; s: PSym; makeUnique: bool = false): string =
  #Module::Type
-  var name = s.name.s & extra
+  var name = s.name.s
  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 =
+proc encodeType*(m: BModule; t: PType): string =
  result = ""
  var kindName = ($t.kind)[2..^1]
  kindName[0] = toLower($kindName[0])[0]
@@ -168,40 +135,36 @@ proc encodeType*(m: BModule; t: PType; staticLists: var string): string =
  of tyObject, tyEnum, tyDistinct, tyUserTypeClass, tyGenericParam:
    result = encodeSym(m, t.sym)
  of tyGenericInst, tyUserTypeClassInst, tyGenericBody:
-    result = encodeName(t.genericHead.sym.name.s)
+    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 encodeType(m, t[i])
    result.add "E"
  of tySequence, tyOpenArray, tyArray, tyVarargs, tyTuple, tyProc, tySet, tyTypeDesc,
-    tyPtr, tyRef, tyVar, tyLent, tySink, tyUncheckedArray, tyOr, tyAnd, tyBuiltInTypeClass:
+    tyPtr, tyRef, tyVar, tyLent, tySink, tyStatic, tyUncheckedArray, tyOr, tyAnd, tyBuiltInTypeClass:
    result =
      case t.kind:
      of tySequence: encodeName("seq")
      else: encodeName(kindName)
    result.add "I"
-    for s in kids(t):
+    for i in 0..<t.len:
+      let s = t[i]
      if s.isNil: continue
-      result.add encodeType(m, s, staticLists)
+      result.add encodeType(m, s)
    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.firstSon.typ.kind in {tyFloat..tyFloat128}:
-      val.addFloat t.n.firstSon.floatVal
+    if t.n[0].typ.kind in {tyFloat..tyFloat128}:
+      val.addFloat t.n[0].floatVal
      val.add "_"
-      val.addFloat t.n.secondSon.floatVal
+      val.addFloat t.n[1].floatVal
    else:
-      val.add $t.n.firstSon.intVal & "_" & $t.n.secondSon.intVal
+      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)
+    result = encodeType(m, t.elementType)
  else:
    assert false, "encodeType " & $t.kind

--- a/compiler/cgen.nim
+++ b/compiler/cgen.nim
--- a/compiler/cgendata.nim
+++ b/compiler/cgendata.nim
@@ -11,7 +11,7 @@

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

 import std/[intsets, tables, sets]

@@ -43,12 +43,12 @@ type
    ctUInt, ctUInt8, ctUInt16, ctUInt32, ctUInt64,
    ctArray, ctPtrToArray, ctStruct, ctPtr, ctNimStr, ctNimSeq, ctProc,
    ctCString
-  TCFileSections* = array[TCFileSection, Builder] # represents a generated C file
+  TCFileSections* = array[TCFileSection, Rope] # represents a generated C file
  TCProcSection* = enum       # the sections a generated C proc consists of
    cpsLocals,                # section of local variables for C proc
    cpsInit,                  # section for init of variables for C proc
    cpsStmts                  # section of local statements for C proc
-  TCProcSections* = array[TCProcSection, Builder] # represents a generated C proc
+  TCProcSections* = array[TCProcSection, Rope] # represents a generated C proc
  BModule* = ref TCGen
  BProc* = ref TCProc
  TBlock* = object
@@ -75,13 +75,10 @@ type
    flags*: set[TCProcFlag]
    lastLineInfo*: TLineInfo  # to avoid generating excessive 'nimln' statements
    currLineInfo*: TLineInfo  # AST codegen will make this superfluous
-    nestedTryStmts*: seq[tuple[fin: PNode, inExcept: bool, isHidden: bool, label: Natural]]
+    nestedTryStmts*: seq[tuple[fin: PNode, inExcept: bool, label: Natural]]
                              # in how many nested try statements we are
                              # (the vars must be volatile then)
-                              # `inExcept` is true when we are in the except part of a try block.
-                              # `isHidden` is true for compiler-injected `nkHiddenTryStmt` wrappers
-                              # (e.g. ARC's destructor try/finally around `except T as e:` bodies);
-                              # finallyActions walks past such wrappers to reach the user's try.
+                              # bool is true when are in the except part of a try block
    finallySafePoints*: seq[Rope]  # For correctly cleaning up exceptions when
                                   # using return in finally statements
    labels*: Natural          # for generating unique labels in the C proc
@@ -91,7 +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
@@ -118,11 +115,11 @@ type
                        # computing alive data on our own.

  BModuleList* = ref object of RootObj
-    mainModProcs*, mainModInit*, otherModsInit*, mainDatInit*: Builder
+    mainModProcs*, mainModInit*, otherModsInit*, mainDatInit*: Rope
    mapping*: Rope             # the generated mapping file (if requested)
-    mods*: seq[BModule]     # list of all compiled modules
+    modules*: seq[BModule]     # list of all compiled modules
    modulesClosed*: seq[BModule] # list of the same compiled modules, but in the order they were closed
-    forwardedProcs*: seq[PSym] # procs that did not yet have a body
+    forwardedProcs*: seq[PSym] # proc:s that did not yet have a body
    generatedHeader*: BModule
    typeInfoMarker*: TypeCacheWithOwner
    typeInfoMarkerV2*: TypeCacheWithOwner
@@ -130,7 +127,7 @@ type
    graph*: ModuleGraph
    strVersion*, seqVersion*: int # version of the string/seq implementation to use

-    nimtv*: Builder         # Nim thread vars; the struct body
+    nimtv*: Rope            # Nim thread vars; the struct body
    nimtvDeps*: seq[PType]  # type deps: every module needs whole struct
    nimtvDeclared*: IntSet  # so that every var/field exists only once
                            # in the struct
@@ -142,13 +139,6 @@ type
                            # not a list of IDs nor can it be made to be one.
    mangledPrcs*: HashSet[string]

-    icEmitted*: IntSet
-      ## Under `--icBackendStage:cg`: the positions of the modules THIS process
-      ## writes a translation unit for. `cgen.findPendingModule` consults it to
-      ## decide where a demanded definition goes — see the comment there. Empty
-      ## outside that stage, which is why every other backend keeps the ordinary
-      ## whole-program routing.
-
  TCGen = object of PPassContext # represents a C source file
    s*: TCFileSections        # sections of the C file
    flags*: set[CodegenFlag]
@@ -165,70 +155,45 @@ type
    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
-    emittedContentDefs*: HashSet[string]
-      # cmdNifC per-module backend: content-addressed C names (generic
-      # instances and synthesized hooks) whose body this TU already emitted.
-      # Distinct symbols (minted in different source modules) can share one
-      # `_i<disamb>` name; `declaredThings` keys on symbol id and lets the
-      # second one through, so we dedup the body by name here instead.
-    queue*: seq[PSym]         # queue of procs to generate
    alive*: IntSet            # symbol IDs of alive data as computed by `dce.nim`
    headerFiles*: seq[string] # needed headers to include
    typeInfoMarker*: TypeCache # needed for generating type information
    typeInfoMarkerV2*: TypeCache
    initProc*: BProc          # code for init procedure
    preInitProc*: BProc       # code executed before the init proc
-    hcrCreateTypeInfosProc*: Builder # type info globals are in here when HCR=on
+    hcrCreateTypeInfosProc*: Rope # type info globals are in here when HCR=on
    inHcrInitGuard*: bool     # We are currently within a HCR reloading guard.
-    hcrInitGuard*: IfBuilder
    typeStack*: TTypeSeq      # used for type generation
    dataCache*: TNodeTable
    typeNodes*, nimTypes*: int # used for type info generation
    typeNodesName*, nimTypesName*: Rope # used for type info generation
    labels*: Natural          # for generating unique module-scope names
-    extensionLoaders*: array['0'..'9', Builder] # special procs for the
+    extensionLoaders*: array['0'..'9', Rope] # special procs for the
                                             # OpenGL wrapper
    sigConflicts*: CountTable[SigHash]
-    icImplMods*: IntSet       # module ids whose routine BODIES this TU
-                              # embeds (redirected defs, shared instances,
-                              # hooks); recorded as the artifact's cdeps so
-                              # the reuse gate can check their impl cookies
-    icGlobalDtorName*: string # per-module backend: the C name of this
-                              # module's global-destructor proc, recorded in
-                              # the artifact's meta head so the main module's
-                              # `cg` — a different process — can call it
-    icDataDefs*: seq[tuple[cname, nifname: string]]
-                              # C names of data definitions (consts, globals,
-                              # RTTI) this TU embeds plus their NIF symbol
-                              # names (empty for RTTI, which has no symbol);
-                              # recorded in the cnif artifact so a later run
-                              # can reuse the TU and re-demand definitions
-                              # that cached TUs still reference
    g*: BModuleList
+    ndi*: NdiFile

 template config*(m: BModule): ConfigRef = m.g.config
 template config*(p: BProc): ConfigRef = p.module.g.config
 template vccAndC*(p: BProc): bool = p.module.config.cCompiler == ccVcc and p.module.config.backend == backendC

-proc delayedCodegen*(m: BModule): bool {.inline.} =
-  useAliveDataFromDce in m.flags or m.config.globalOptions.contains(optCompress)
-
 proc includeHeader*(this: BModule; header: string) =
  if not this.headerFiles.contains header:
    this.headerFiles.add header

-proc s*(p: BProc, s: TCProcSection): var Builder {.inline.} =
+proc s*(p: BProc, s: TCProcSection): var Rope {.inline.} =
  # section in the current block
  result = p.blocks[^1].sections[s]

-proc procSec*(p: BProc, s: TCProcSection): var Builder {.inline.} =
+proc procSec*(p: BProc, s: TCProcSection): var Rope {.inline.} =
  # top level proc sections
  result = p.blocks[0].sections[s]

 proc initBlock*(): TBlock =
  result = TBlock()
  for i in low(result.sections)..high(result.sections):
-    result.sections[i] = newBuilder("")
+    result.sections[i] = newRopeAppender()

 proc newProc*(prc: PSym, module: BModule): BProc =
  result = BProc(
@@ -245,8 +210,7 @@ proc newProc*(prc: PSym, module: BModule): BProc =

 proc newModuleList*(g: ModuleGraph): BModuleList =
  BModuleList(typeInfoMarker: initTable[SigHash, tuple[str: Rope, owner: int32]](),
-    config: g.config, graph: g, nimtvDeclared: initIntSet(),
-    icEmitted: initIntSet())
+    config: g.config, graph: g, nimtvDeclared: initIntSet())

 iterator cgenModules*(g: BModuleList): BModule =
  for m in g.modulesClosed:
--- a/compiler/cgmeth.nim
+++ b/compiler/cgmeth.nim
@@ -123,8 +123,8 @@ proc attachDispatcher(s: PSym, dispatcher: PNode) =

 proc createDispatcher(s: PSym; g: ModuleGraph; idgen: IdGenerator): PSym =
  var disp = copySym(s, idgen)
-  incl(disp, sfDispatcher)
-  excl(disp, sfExported)
+  incl(disp.flags, sfDispatcher)
+  excl(disp.flags, sfExported)
  let old = disp.typ
  disp.typ = copyType(disp.typ, idgen, disp.typ.owner)
  copyTypeProps(g, idgen.module, disp.typ, old)
@@ -133,7 +133,7 @@ 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.locImpl.snippet = ""
+  disp.loc.r = ""
  if s.typ.returnType != nil:
    if disp.ast.len > resultPos:
      disp.ast[resultPos].sym = copySym(s.ast[resultPos].sym, idgen)
@@ -160,17 +160,7 @@ 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") and sfFromGeneric notin s.flags:
-    # `sfFromGeneric` excepted: this is the same-module restriction for vtable
-    # slot placement, and it must be judged on the GENERIC method, not on an
-    # instance. The generic `method skip[T](x: Input[T])` never reaches here
-    # (`semMethodPrototype` registers generic methods via `addMethodToGeneric`,
-    # bypassing `methodDef`); only its instance `skip[string]` does, and that
-    # instance's first-param type `Input[string]` is owned by whichever module
-    # first instantiated it (`tparsecombnum`, which `import parsecomb`s and uses
-    # it), NOT by `Input[T]`'s defining module — so the comparison spuriously
-    # fails for a method that is perfectly legal at the generic level. (Concrete
-    # methods, `sfFromGeneric notin flags`, are still checked.)
+      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:
@@ -190,19 +180,17 @@ proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
           g.methods[i].methods[0] != s:
        # already exists due to forwarding definition?
        localError(g.config, s.info, "method is not a base")
-      logMethodDef(g, s)
      return
    of No: discard
    of Invalid:
      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).bindingId notin g.bucketTable:
-    g.bucketTable[s.typ.firstParamType.skipTypes(skipPtrs).bindingId] = 1
+  if s.typ.firstParamType.skipTypes(skipPtrs).itemId notin g.bucketTable:
+    g.bucketTable[s.typ.firstParamType.skipTypes(skipPtrs).itemId] = 1
  else:
-    g.bucketTable.inc(s.typ.firstParamType.skipTypes(skipPtrs).bindingId)
+    g.bucketTable.inc(s.typ.firstParamType.skipTypes(skipPtrs).itemId)
  g.methods.add((methods: @[s], dispatcher: createDispatcher(s, g, idgen)))
-  logMethodDef(g, s)
  #echo "adding ", s.info
  if witness != nil:
    localError(g.config, s.info, "invalid declaration order; cannot attach '" & s.name.s &
--- a/compiler/closureiters.nim
+++ b/compiler/closureiters.nim
--- a/compiler/cmdlinehelper.nim
+++ b/compiler/cmdlinehelper.nim
@@ -53,8 +53,7 @@ proc processCmdLineAndProjectPath*(self: NimProg, conf: ConfigRef) =
 proc loadConfigsAndProcessCmdLine*(self: NimProg, cache: IdentCache; conf: ConfigRef;
                                   graph: ModuleGraph): bool =
  if self.suggestMode:
-    conf.setCmd cmdCheck
-    conf.ideActive = true
+    conf.setCmd cmdIdeTools
  if conf.cmd == cmdNimscript:
    incl(conf.globalOptions, optWasNimscript)
  loadConfigs(DefaultConfig, cache, conf, graph.idgen) # load all config files
--- a/compiler/cnif.nim
+++ b/compiler/cnif.nim
@@ -1,740 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2026 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## The "cnif" artifact: the C code generator's output as a NIF file.
-##
-## This is deliberately *not* NIFC: the C text is kept verbatim (Nim's
-## C-level machinery — exception handling in particular — is more refined
-## than what NIFC models today; the gap can be closed incrementally later).
-## The only structure the artifact adds is the part dead code elimination
-## and generic-instance merging need:
-##
-## - raw C text as string literals
-## - every *global* entity's C name as a `Symbol` token
-## - every emitted proc definition as a `(cdef SymbolDef flags ...)` group
-##
-## The C generator marks names with control characters at the single place
-## a global's C name is minted (`fillBackendName`) and emits a definition
-## directive at the single place finished procs are appended; the marks then
-## ride through all of the snippet composition untouched. This module turns
-## the final marked module text into the `.c.nif` artifact and strips the
-## marks for the actual `.c` output. Rendering C from the artifact is a
-## plain token walk: string literals verbatim, symbols by name — which is
-## also where a later merge step redirects losing generic instances.
-##
-## Marker scheme (cannot collide: C string literals escape control chars,
-## and `\1`/`\31`/`\23` of cgen's postprocess directives are distinct):
-##   \2 name \3                       a global's C name
-##   \4 name \31 flags \31 nif \5     start of the definition of `name`;
-##                                    `nif` is the defining symbol's NIF name
-##                                    (empty for backend-minted symbols) so a
-##                                    later run can re-demand the definition
-##   \4 \5                            end of the definitions section
-
-import std / [tables, sets, os, assertions, syncio, algorithm]
-import "../dist/nimony/src/lib" / [nifbuilder, nifcoreparse]
-
-const
-  CnifSymStart* = '\2'
-  CnifSymEnd* = '\3'
-  CnifDefStart* = '\4'
-  CnifDefSep* = '\31'   # same separator char as cgen's postprocess directives
-  CnifDefEnd* = '\5'
-
-proc markCName*(name: string): string {.inline.} =
-  CnifSymStart & name & CnifSymEnd
-
-proc hasCnifMarks*(s: string): bool =
-  for c in s:
-    if c in {CnifSymStart, CnifSymEnd, CnifDefStart}: return true
-  false
-
-proc stripCnifMarks*(s: string): string =
-  ## Removes the symbol marks (keeping the names) and the definition
-  ## directives (entirely) so the result is plain C.
-  if not hasCnifMarks(s): return s
-  result = newStringOfCap(s.len)
-  var i = 0
-  while i < s.len:
-    case s[i]
-    of CnifSymStart, CnifSymEnd:
-      inc i
-    of CnifDefStart:
-      while i < s.len and s[i] != CnifDefEnd: inc i
-      inc i # skip CnifDefEnd
-    else:
-      result.add s[i]
-      inc i
-
-const
-  CnifVersion* = "5"
-    ## Artifact format version, stored in the meta head. Artifacts written
-    ## by an older compiler lack the NIF names and the cref group the
-    ## def-retention check needs (v2), the cdeps group the fine-grained
-    ## reuse gate needs (v3), the type NIF names and cnif-marked extern
-    ## RTTI references the typeinfo flavor of the def-retention check
-    ## needs (v4), or the global-destructor name the main module's `cg`
-    ## calls at teardown (v5); `readCnifHeads` reports them as invalid so
-    ## their TUs simply regenerate once.
-
-proc cnifDefDirective*(name, flags, nifName: string): string =
-  CnifDefStart & name & CnifDefSep & flags & CnifDefSep & nifName & CnifDefEnd
-
-proc cnifEndDefs*(): string =
-  CnifDefStart & CnifDefEnd
-
-proc writeCnifArtifact*(code: string; outfile: string;
-                        initRequired = false; datInitRequired = false;
-                        dataDefs: openArray[tuple[cname, nifname: string]] = [];
-                        semmedNif = ""; moduleBase = ""; globalDtor = "";
-                        implDeps: openArray[string] = []) =
-  ## Splits the marked module text into the `.c.nif` artifact.
-  ## The artifact starts with a `(meta <flags> "semmedNif" "moduleBase"
-  ## "version" "globalDtor")` head — whether the module has an init/datInit
-  ## proc ('i'/'d'), which semmed NIF it was generated from, the module's
-  ## mangled base name (what `registerModuleToMain` and the reuse decision
-  ## need when the TU is reused in a later run, possibly without the module
-  ## ever being loaded again) and the C name of the module's global-destructor
-  ## proc, if any (what the main module's `cg` calls at program teardown; see
-  ## `cgen.genIcModuleDestroyGlobals`) — a `(cdata (SymbolDef StrLit)*)` group naming
-  ## the data definitions (consts, globals, RTTI) the TU embeds together
-  ## with their NIF names, a `(cref Ident*)` group naming every C name
-  ## the TU references but does not define itself (what the def-retention
-  ## check consults when some *other* TU regenerates), and a
-  ## `(cdeps Ident*)` group naming the modules whose routine *bodies* this
-  ## TU embeds (redirected defs, shared instances, hooks): the fine-grained
-  ## reuse gate checks their `.impl.nif` cookies on top of the direct
-  ## imports' `.iface.nif` cookies.
-  # pre-pass: every marked name is a use, every definition directive (and
-  # every data def) is a definition; external references = uses - defs
-  var uses = initHashSet[string]()
-  var defs = initHashSet[string]()
-  block prePass:
-    var i = 0
-    while i < code.len:
-      case code[i]
-      of CnifSymStart:
-        inc i
-        var name = ""
-        while i < code.len and code[i] != CnifSymEnd:
-          name.add code[i]
-          inc i
-        inc i
-        uses.incl name
-      of CnifDefStart:
-        inc i
-        var payload = ""
-        while i < code.len and code[i] != CnifDefEnd:
-          payload.add code[i]
-          inc i
-        inc i
-        let sep = find(payload, CnifDefSep)
-        if sep > 0: defs.incl payload[0..<sep]
-        elif payload.len > 0: defs.incl payload
-      else:
-        inc i
-  for d in dataDefs: defs.incl d.cname
-  var crefs: seq[string] = @[]
-  for u in uses:
-    if u notin defs: crefs.add u
-  sort crefs
-
-  var b = nifbuilder.open(outfile)
-  b.withTree "stmts":
-    b.withTree "meta":
-      var metaFlags = ""
-      if initRequired: metaFlags.add 'i'
-      if datInitRequired: metaFlags.add 'd'
-      if metaFlags.len > 0: b.addIdent metaFlags
-      else: b.addEmpty
-      b.addStrLit semmedNif
-      b.addStrLit moduleBase
-      b.addStrLit CnifVersion
-      b.addStrLit globalDtor
-    b.withTree "cdata":
-      for d in dataDefs:
-        b.addSymbolDef d.cname
-        b.addStrLit d.nifname
-    b.withTree "cref":
-      for r in crefs:
-        b.addIdent r
-    b.withTree "cdeps":
-      for s in implDeps:
-        b.addIdent s
-    var raw = ""
-    var inDef = false
-    template flushRaw() =
-      if raw.len > 0:
-        b.addStrLit raw
-        raw.setLen 0
-    var i = 0
-    while i < code.len:
-      case code[i]
-      of CnifSymStart:
-        flushRaw()
-        inc i
-        var name = ""
-        while i < code.len and code[i] != CnifSymEnd:
-          name.add code[i]
-          inc i
-        inc i # skip CnifSymEnd
-        b.addSymbol name, ""
-      of CnifDefStart:
-        flushRaw()
-        inc i
-        var payload = ""
-        while i < code.len and code[i] != CnifDefEnd:
-          payload.add code[i]
-          inc i
-        inc i # skip CnifDefEnd
-        if inDef:
-          b.endTree()
-          inDef = false
-        if payload.len > 0:
-          let sep = find(payload, CnifDefSep)
-          let name = if sep >= 0: payload[0..<sep] else: payload
-          var flags = if sep >= 0: payload[sep+1..^1] else: ""
-          var nifName = ""
-          let sep2 = find(flags, CnifDefSep)
-          if sep2 >= 0:
-            nifName = flags[sep2+1..^1]
-            flags = flags[0..<sep2]
-          b.addTree "cdef"
-          b.addSymbolDef name
-          if flags.len > 0: b.addIdent flags
-          else: b.addEmpty
-          b.addStrLit nifName
-          inDef = true
-      else:
-        raw.add code[i]
-        inc i
-    flushRaw()
-    if inDef:
-      b.endTree()
-  b.close()
-
-proc renderMarkedC*(code: string; live: HashSet[string]; dropped: var int): string =
-  ## Renders the final C text from the marked module text: symbol marks are
-  ## removed (keeping the names — a later merge step substitutes them here),
-  ## and definitions whose name is not in `live` are dropped entirely. Each
-  ## definition is self-delimiting (genProcAux emits an end directive right
-  ## after the proc's text), so text written by other emitters is never part
-  ## of a definition's span and survives unconditionally.
-  result = newStringOfCap(code.len)
-  var i = 0
-  while i < code.len:
-    case code[i]
-    of CnifSymStart, CnifSymEnd:
-      inc i
-    of CnifDefStart:
-      var payload = ""
-      inc i
-      while i < code.len and code[i] != CnifDefEnd:
-        payload.add code[i]
-        inc i
-      inc i # skip CnifDefEnd
-      if payload.len > 0:
-        let sep = find(payload, CnifDefSep)
-        let name = if sep >= 0: payload[0..<sep] else: payload
-        if name notin live:
-          inc dropped
-          # drop the definition's text: everything up to its end directive
-          while i < code.len and code[i] != CnifDefStart: inc i
-    else:
-      result.add code[i]
-      inc i
-
-# ---- Liveness over the artifact -------------------------------------------
-
-proc symOrIdentName(c: Cursor): string {.inline.} =
-  if c.kind == Ident: strVal(c) else: symName(c)
-
-type
-  CnifHeads* = object
-    ## The cheap-to-parse part of an artifact that a later run needs in
-    ## order to reuse the TU without regenerating it.
-    valid*: bool             ## file parsed, carries the meta head and has
-                             ## the current format version
-    initRequired*: bool
-    datInitRequired*: bool
-    semmedNif*: string       ## the semmed NIF this TU was generated from
-    moduleBase*: string      ## the module's mangled base name
-    globalDtor*: string      ## C name of the module's global-destructor proc
-                             ## ("" when the module has no global destructors)
-    cdefs*: seq[tuple[cname, nifname: string]] ## the proc definitions
-    cdata*: seq[tuple[cname, nifname: string]] ## the data definitions
-    crefs*: seq[string]      ## C names referenced but not defined here
-    cdeps*: seq[string]      ## module suffixes whose routine bodies this
-                             ## TU embeds (impl-cookie gated on reuse)
-
-proc readCnifHeads*(f: string): CnifHeads =
-  ## Reads `(meta ...)`, `(cdata ...)`, `(cref ...)` and the `(cdef ...)`
-  ## head names from an artifact. Artifacts written by an older compiler
-  ## (no meta head or a different format version) report `valid=false`.
-  result = CnifHeads()
-  if not fileExists(f): return
-  var pool = newPool()
-  var tags = newTagPool()
-  let stmtsTag = tags.registerTag("stmts")
-  let cdefTag = tags.registerTag("cdef")
-  let cdataTag = tags.registerTag("cdata")
-  let crefTag = tags.registerTag("cref")
-  let cdepsTag = tags.registerTag("cdeps")
-  let metaTag = tags.registerTag("meta")
-  var buf = parseFromFile(f, 1000, pool, tags)
-  var c = beginRead(buf)
-  if c.kind != TagLit or c.cursorTagId != stmtsTag:
-    endRead(c)
-    return
-  var version = ""
-  var sawMeta = false
-  c.loopInto:
-    if c.kind == TagLit:
-      if c.cursorTagId == metaTag:
-        sawMeta = true
-        var strIdx = 0
-        c.loopInto:
-          if c.kind == Ident:
-            for ch in strVal(c):
-              if ch == 'i': result.initRequired = true
-              elif ch == 'd': result.datInitRequired = true
-            inc c
-          elif c.kind == StrLit:
-            if strIdx == 0: result.semmedNif = strVal(c)
-            elif strIdx == 1: result.moduleBase = strVal(c)
-            elif strIdx == 2: version = strVal(c)
-            elif strIdx == 3: result.globalDtor = strVal(c)
-            inc strIdx
-            inc c
-          else:
-            skip c
-      elif c.cursorTagId == cdataTag:
-        c.loopInto:
-          if c.kind == SymbolDef:
-            result.cdata.add (symName(c), "")
-            inc c
-          elif c.kind == StrLit:
-            if result.cdata.len > 0:
-              result.cdata[^1].nifname = strVal(c)
-            inc c
-          else:
-            skip c
-      elif c.cursorTagId == crefTag:
-        c.loopInto:
-          if c.kind in {Ident, Symbol, SymbolDef}:
-            result.crefs.add symOrIdentName(c)
-            inc c
-          else:
-            skip c
-      elif c.cursorTagId == cdepsTag:
-        c.loopInto:
-          if c.kind in {Ident, Symbol, SymbolDef}:
-            result.cdeps.add symOrIdentName(c)
-            inc c
-          else:
-            skip c
-      elif c.cursorTagId == cdefTag:
-        # fixed head: SymbolDef, flags (Ident or empty), NIF name StrLit;
-        # everything after that is the definition's body text
-        var state = 0
-        c.loopInto:
-          if c.kind == SymbolDef:
-            result.cdefs.add (symName(c), "")
-            state = 1
-            inc c
-          elif state == 1: # the flags field
-            state = 2
-            skip c
-          elif state == 2: # the NIF name
-            if c.kind == StrLit and result.cdefs.len > 0:
-              result.cdefs[^1].nifname = strVal(c)
-            state = 3
-            skip c
-          else:
-            skip c
-      else:
-        skip c
-    else:
-      skip c
-  endRead(c)
-  result.valid = sawMeta and version == CnifVersion
-
-type
-  CnifLiveness* = object
-    defs*: int      ## proc definitions emitted across all modules
-    liveDefs*: int  ## of those, reachable from the roots
-    live*: HashSet[string] ## live C names
-    broken*: bool
-
-proc computeLiveFromCArtifacts*(files: openArray[string]): CnifLiveness =
-  ## dce1-style mark&sweep over the C-shaped artifacts: a `(cdef ...)`
-  ## group is a definition (flags 'x'/'c'/'m' — exportc, compilerproc,
-  ## method/dispatcher — make it a root), names at the top level (data,
-  ## globals, init code) are roots, names inside a group are its uses.
-  ## Because the artifact is *fully lowered* output, no conservative
-  ## modelling is needed: every call the C code contains is a token here.
-  ##
-  ## NB: mangled C names contain no dots, so NIF's text reader classifies
-  ## them as `Ident` rather than `Symbol`; the dialect therefore treats
-  ## Ident tokens as name uses. Inside a `(cdef ...)` the flags ident is
-  ## the one immediately following the SymbolDef; everything after is a use.
-  result = CnifLiveness(live: initHashSet[string]())
-  var pool = newPool()
-  var tags = newTagPool()
-  let stmtsTag = tags.registerTag("stmts")
-  let cdefTag = tags.registerTag("cdef")
-  let cdataTag = tags.registerTag("cdata")
-  let crefTag = tags.registerTag("cref")
-  let cdepsTag = tags.registerTag("cdeps")
-  let metaTag = tags.registerTag("meta")
-  var uses = initTable[string, HashSet[string]]()
-  var roots = initHashSet[string]()
-  var defs = initHashSet[string]()
-  for f in files:
-    if not fileExists(f):
-      result.broken = true
-      return
-    var buf = parseFromFile(f, 1000, pool, tags)
-    var c = beginRead(buf)
-    if c.kind != TagLit or c.cursorTagId != stmtsTag:
-      result.broken = true
-      endRead(c)
-      return
-    c.loopInto:
-      case c.kind
-      of Symbol, Ident:
-        roots.incl symOrIdentName(c)
-        inc c
-      of TagLit:
-        if c.cursorTagId == metaTag or c.cursorTagId == cdataTag or
-            c.cursorTagId == crefTag or c.cursorTagId == cdepsTag:
-          # bookkeeping for TU reuse, irrelevant for liveness
-          skip c
-        elif c.cursorTagId == cdefTag:
-          var owner = ""
-          var flagsSeen = false
-          c.loopInto:
-            case c.kind
-            of SymbolDef:
-              owner = symName(c)
-              defs.incl owner
-              flagsSeen = false
-              inc c
-            of Symbol, Ident:
-              let name = symOrIdentName(c)
-              if not flagsSeen:
-                # the flags field right after the SymbolDef
-                flagsSeen = true
-                for ch in name:
-                  # 'd' marks a data definition (const/RTTI): never DCE'd, so it
-                  # is a root whose body keeps its referenced procs live
-                  if ch in {'x', 'c', 'm', 'd'}:
-                    roots.incl owner
-                    break
-              else:
-                uses.mgetOrPut(owner, initHashSet[string]()).incl name
-              inc c
-            of DotToken:
-              flagsSeen = true # empty flags field
-              inc c
-            else:
-              skip c
-        else:
-          c.loopInto:
-            if c.kind in {Symbol, Ident}:
-              roots.incl symOrIdentName(c)
-              inc c
-            else:
-              skip c
-      else:
-        skip c
-    endRead(c)
-  # mark & sweep
-  var work = newSeqOfCap[string](roots.len)
-  for r in roots: work.add r
-  while work.len > 0:
-    let s = work.pop()
-    if not result.live.containsOrIncl(s):
-      if uses.hasKey(s):
-        for dep in uses[s]:
-          if dep notin result.live:
-            work.add dep
-  result.defs = defs.len
-  for d in defs:
-    if d in result.live: inc result.liveDefs
-
-# ---- The merge stage: liveness + owner assignment -------------------------
-
-type
-  MergeDecision* = object
-    ## What the per-module backend's `merge` stage computes from every
-    ## module's `.c.nif` and what its `emit` stage consumes to render the
-    ## final `.c` of one module.
-    live*: HashSet[string]        ## globally reachable C names (dead cdefs
-                                  ## are dropped from every module)
-    owners*: Table[string, string] ## for each `'u'`-flagged (unique,
-                                  ## externally-linked) definition, the single
-                                  ## artifact base name allowed to embed its
-                                  ## body; every other module prototypes it
-    broken*: bool                 ## an artifact was missing or unparsable —
-                                  ## the caller should fall back / regenerate
-    defs*, liveDefs*: int
-
-proc computeMergeDecision*(files: openArray[string]): MergeDecision =
-  ## One pass over every `.c.nif`: the same mark&sweep as
-  ## `computeLiveFromCArtifacts` plus, per definition, owner assignment.
-  ##
-  ## Each `cg` process emits the body of every definition it demands
-  ## (emit-everywhere), so the same externally-linked definition appears in
-  ## several artifacts. A `'u'` flag on the `(cdef ...)` marks those that need
-  ## exactly one owner, assigned here across processes: the owner is the
-  ## lexicographically smallest artifact that emits it — a pure function of the
-  ## claimant set, hence stable across rebuilds. Definitions without `'u'`
-  ## (inline procs, dispatchers) are `static`/main-only and emitted into every
-  ## using TU, so they get no owner entry and are never deduplicated.
-  result = MergeDecision(live: initHashSet[string](),
-                         owners: initTable[string, string]())
-  var pool = newPool()
-  var tags = newTagPool()
-  let stmtsTag = tags.registerTag("stmts")
-  let cdefTag = tags.registerTag("cdef")
-  let cdataTag = tags.registerTag("cdata")
-  let crefTag = tags.registerTag("cref")
-  let cdepsTag = tags.registerTag("cdeps")
-  let metaTag = tags.registerTag("meta")
-  var uses = initTable[string, HashSet[string]]()
-  var roots = initHashSet[string]()
-  var defs = initHashSet[string]()
-  for f in files:
-    if not fileExists(f):
-      result.broken = true
-      return
-    let owner = extractFilename(f)
-    var buf = parseFromFile(f, 1000, pool, tags)
-    var c = beginRead(buf)
-    if c.kind != TagLit or c.cursorTagId != stmtsTag:
-      result.broken = true
-      endRead(c)
-      return
-    c.loopInto:
-      case c.kind
-      of Symbol, Ident:
-        roots.incl symOrIdentName(c)
-        inc c
-      of TagLit:
-        if c.cursorTagId == metaTag or c.cursorTagId == cdataTag or
-            c.cursorTagId == crefTag or c.cursorTagId == cdepsTag:
-          skip c
-        elif c.cursorTagId == cdefTag:
-          var ownerName = ""
-          var flagsSeen = false
-          var needsOwner = false
-          c.loopInto:
-            case c.kind
-            of SymbolDef:
-              ownerName = symName(c)
-              defs.incl ownerName
-              flagsSeen = false
-              inc c
-            of Symbol, Ident:
-              let name = symOrIdentName(c)
-              if not flagsSeen:
-                flagsSeen = true
-                for ch in name:
-                  if ch in {'x', 'c', 'm'}: roots.incl ownerName
-                  # 'u' = unique proc (DCE'd), 'd' = data (never DCE'd, hence a
-                  # root); both need a single owner across the emit-everywhere
-                  # processes
-                  elif ch == 'u': needsOwner = true
-                  elif ch == 'd':
-                    needsOwner = true
-                    roots.incl ownerName
-              else:
-                uses.mgetOrPut(ownerName, initHashSet[string]()).incl name
-              inc c
-            of DotToken:
-              flagsSeen = true # empty flags field
-              inc c
-            else:
-              skip c
-          if needsOwner and ownerName.len > 0:
-            # smallest claimant wins; ties impossible (one entry per name)
-            let prev = result.owners.getOrDefault(ownerName, "")
-            if prev.len == 0 or owner < prev:
-              result.owners[ownerName] = owner
-        else:
-          c.loopInto:
-            if c.kind in {Symbol, Ident}:
-              roots.incl symOrIdentName(c)
-              inc c
-            else:
-              skip c
-      else:
-        skip c
-    endRead(c)
-  var work = newSeqOfCap[string](roots.len)
-  for r in roots: work.add r
-  while work.len > 0:
-    let s = work.pop()
-    if not result.live.containsOrIncl(s):
-      if uses.hasKey(s):
-        for dep in uses[s]:
-          if dep notin result.live:
-            work.add dep
-  result.defs = defs.len
-  for d in defs:
-    if d in result.live: inc result.liveDefs
-
-const MergeDecisionFile* = "ic.backend.merge.nif"
-const LiveModulesFile* = "ic.backend.live.txt"
-  ## One `.c.nif` path per line: exactly the artifacts of the modules the CURRENT
-  ## build graph considers live. The `merge` stage reads this instead of globbing
-  ## `*.c.nif` off the nimcache, so a leftover artifact from an unrelated build
-  ## that happens to share the cache directory cannot be merged in (which is what
-  ## made a shared prebuilt cache unusable: merge picked owners in modules the
-  ## program does not import, and the link then wanted their objects).
-  ## Fixed name of the merge stage's output in the nimcache, read by `emit`.
-
-proc writeMergeDecision*(outfile: string; d: MergeDecision) =
-  ## Serializes the merge decision: `(merge (live Symbol*) (owners (own
-  ## Symbol StrLit)*))`. C names are mangled (no dots) so they serialize as
-  ## symbols; owner artifact base names go in string literals.
-  var live: seq[string] = @[]
-  for n in d.live: live.add n
-  sort live
-  var keys: seq[string] = @[]
-  for k in d.owners.keys: keys.add k
-  sort keys
-  var b = nifbuilder.open(outfile)
-  b.withTree "merge":
-    b.withTree "live":
-      for n in live: b.addSymbol n, ""
-    b.withTree "owners":
-      for k in keys:
-        b.withTree "own":
-          b.addSymbol k, ""
-          b.addStrLit d.owners[k]
-  b.close()
-
-proc readMergeDecision*(f: string): MergeDecision =
-  ## Reads back a `writeMergeDecision` file; `broken=true` if absent/unparsable.
-  result = MergeDecision(live: initHashSet[string](),
-                         owners: initTable[string, string]())
-  if not fileExists(f):
-    result.broken = true
-    return
-  var pool = newPool()
-  var tags = newTagPool()
-  let mergeTag = tags.registerTag("merge")
-  let liveTag = tags.registerTag("live")
-  let ownersTag = tags.registerTag("owners")
-  let ownTag = tags.registerTag("own")
-  var buf = parseFromFile(f, 1000, pool, tags)
-  var c = beginRead(buf)
-  if c.kind != TagLit or c.cursorTagId != mergeTag:
-    result.broken = true
-    endRead(c)
-    return
-  c.loopInto:
-    if c.kind == TagLit and c.cursorTagId == liveTag:
-      c.loopInto:
-        if c.kind in {Symbol, Ident}:
-          result.live.incl symOrIdentName(c)
-          inc c
-        else:
-          skip c
-    elif c.kind == TagLit and c.cursorTagId == ownersTag:
-      c.loopInto:
-        if c.kind == TagLit and c.cursorTagId == ownTag:
-          var key = ""
-          c.loopInto:
-            if c.kind in {Symbol, Ident}:
-              key = symOrIdentName(c)
-              inc c
-            elif c.kind == StrLit:
-              if key.len > 0: result.owners[key] = strVal(c)
-              inc c
-            else:
-              skip c
-        else:
-          skip c
-    else:
-      skip c
-  endRead(c)
-
-proc renderCFromArtifact*(artifact: string; d: MergeDecision; ownerId: string;
-                          dropped: var int): string =
-  ## The per-module backend's `emit` stage: render one module's final `.c` from
-  ## its `.c.nif` and the merge decision. String literals are emitted verbatim,
-  ## symbols by name; a `(cdef ...)` body is dropped when the name is dead, or
-  ## when it is a `'u'` unique definition this module does not own. The body's
-  ## prototype lives in the surrounding raw text (cgen emits a forward
-  ## declaration for every *used* proc, independent of where the body lands), so
-  ## a dropped body still leaves a valid declaration — no synthesis needed. The
-  ## head groups (meta/cdata/cref/cdeps) carry no C text.
-  result = ""
-  if not fileExists(artifact): return
-  var pool = newPool()
-  var tags = newTagPool()
-  let stmtsTag = tags.registerTag("stmts")
-  let cdefTag = tags.registerTag("cdef")
-  var buf = parseFromFile(artifact, 1000, pool, tags)
-  var c = beginRead(buf)
-  if c.kind != TagLit or c.cursorTagId != stmtsTag:
-    endRead(c)
-    return
-  c.loopInto:
-    case c.kind
-    of StrLit:
-      result.add strVal(c)
-      inc c
-    of Symbol, Ident:
-      result.add symOrIdentName(c)
-      inc c
-    of TagLit:
-      if c.cursorTagId == cdefTag:
-        # fixed head: SymbolDef, flags (Ident or empty), nifname StrLit; the
-        # rest is the definition's body text. `state` counts past the head.
-        var name = ""
-        var isUnique = false
-        var isData = false
-        var keep = true
-        var state = 0
-        c.loopInto:
-          if state == 0 and c.kind == SymbolDef:
-            name = symName(c)
-            state = 1
-            inc c
-          elif state == 1: # the flags field (one token: Ident/Symbol or empty)
-            if c.kind in {Ident, Symbol}:
-              for ch in symOrIdentName(c):
-                if ch == 'u': isUnique = true
-                elif ch == 'd': isData = true
-            state = 2
-            inc c
-          elif state == 2: # the NIF name (one StrLit) — decide keep here
-            let owned = d.owners.getOrDefault(name, ownerId) == ownerId
-            keep =
-              if isData: owned                      # data: kept by its owner only
-              elif isUnique: (name in d.live) and owned
-              else: name in d.live                  # inline/dispatcher: per-TU
-            if not keep: inc dropped
-            state = 3
-            inc c
-          else: # body tokens
-            if keep:
-              if c.kind == StrLit: result.add strVal(c)
-              elif c.kind in {Symbol, Ident}: result.add symOrIdentName(c)
-            inc c
-      else:
-        # head groups (meta/cdata/cref/cdeps) carry no C text
-        skip c
-    else:
-      inc c
-  endRead(c)
--- 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, sets, 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
@@ -118,7 +118,7 @@ const
  errInvalidCmdLineOption = "invalid command line option: '$1'"
  errOnOrOffExpectedButXFound = "'on' or 'off' expected, but '$1' found"
  errOnOffOrListExpectedButXFound = "'on', 'off' or 'list' expected, but '$1' found"
-  errOffHintsError = "'off', 'hint', 'warning', 'error' or 'usages' expected, but '$1' found"
+  errOffHintsError = "'off', 'hint', 'error' or 'usages' expected, but '$1' found"

 proc invalidCmdLineOption(conf: ConfigRef; pass: TCmdLinePass, switch: string, info: TLineInfo) =
  if switch == " ": localError(conf, info, errInvalidCmdLineOption % "-")
@@ -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
@@ -245,12 +244,10 @@ proc processCompile(conf: ConfigRef; filename: string) =
  extccomp.addExternalFileToCompile(conf, found)

 const
-  errNoneBoehmRefcExpectedButXFound = "'arc', 'orc', 'yrc', 'atomicArc', 'markAndSweep', 'boehm', 'go', 'none', 'regions', or 'refc' expected, but '$1' found"
+  errNoneBoehmRefcExpectedButXFound = "'arc', 'orc', 'atomicArc', 'markAndSweep', 'boehm', 'go', 'none', 'regions', or 'refc' expected, but '$1' found"
  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"
-  errDefaultOrSsoExpectedButXFound = "'default' or 'sso' expected, but '$1' found"

 template warningOptionNoop(switch: string) =
  warningDeprecated(conf, info, "'$#' is deprecated, now a noop" % switch)
@@ -267,7 +264,6 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
    of "markandsweep": result = conf.selectedGC == gcMarkAndSweep
    of "destructors", "arc": result = conf.selectedGC == gcArc
    of "orc": result = conf.selectedGC == gcOrc
-    of "yrc": result = conf.selectedGC == gcYrc
    of "hooks": result = conf.selectedGC == gcHooks
    of "go": result = conf.selectedGC == gcGo
    of "none": result = conf.selectedGC == gcNone
@@ -307,19 +303,6 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
    else:
      result = false
      localError(conf, info, errInvalidExceptionSystem % arg)
-  of "strings":
-    case arg.normalize
-    of "default": result = conf.selectedStrings == stringDefault
-    of "sso": result = conf.selectedStrings == stringSso
-    else:
-      result = false
-      localError(conf, info, errDefaultOrSsoExpectedButXFound % 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)
@@ -373,7 +356,6 @@ proc testCompileOption*(conf: ConfigRef; switch: string, info: TLineInfo): bool
    result = false
  of "panics": result = contains(conf.globalOptions, optPanics)
  of "jsbigint64": result = contains(conf.globalOptions, optJsBigInt64)
-  of "mangle": result = contains(conf.globalOptions, optItaniumMangle)
  else:
    result = false
    invalidCmdLineOption(conf, passCmd1, switch, info)
@@ -469,7 +451,7 @@ template handleStdinOrCmdInput =
    conf.outDir = getNimcacheDir(conf)

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

@@ -483,7 +465,6 @@ proc parseCommand*(command: string): Command =
  of "cpp", "compiletocpp": cmdCompileToCpp
  of "objc", "compiletooc": cmdCompileToOC
  of "js", "compiletojs": cmdCompileToJS
-  of "nif": cmdCompileToNif
  of "r": cmdCrun
  of "m": cmdM
  of "run": cmdTcc
@@ -503,13 +484,10 @@ proc parseCommand*(command: string): Command =
  of "gendepend": cmdGendepend
  of "dump": cmdDump
  of "parse": cmdParse
+  of "rod": cmdRod
  of "secret": cmdInteractive
  of "nop", "help": cmdNop
  of "jsonscript": cmdJsonscript
-  of "nifc": cmdNifC  # generate C from NIF files
-  of "ic": cmdIc  # generate .build.nif for nifmake
-  of "icconfig": cmdIcConfig  # produce the precompiled config artifact
-  of "track": cmdTrack  # IDE goto-def / find-usages over `nim ic`'s NIF output
  else: cmdUnknown

 proc setCmd*(conf: ConfigRef, cmd: Command) =
@@ -521,12 +499,6 @@ proc setCmd*(conf: ConfigRef, cmd: Command) =
  of cmdCompileToCpp: conf.backend = backendCpp
  of cmdCompileToOC: conf.backend = backendObjc
  of cmdCompileToJS: conf.backend = backendJs
-  of cmdCompileToNif: conf.backend = backendNif
-  of cmdNifC:
-    conf.backend = backendC  # NIF to C compilation
-  of cmdM:
-    # cmdM requires optCompress for proper IC handling (include files, etc.)
-    conf.globalOptions.incl optCompress
  else: discard

 proc setCommandEarly*(conf: ConfigRef, command: string) =
@@ -581,7 +553,6 @@ proc unregisterArcOrc*(conf: ConfigRef) =
  undefSymbol(conf.symbols, "gcdestructors")
  undefSymbol(conf.symbols, "gcarc")
  undefSymbol(conf.symbols, "gcorc")
-  undefSymbol(conf.symbols, "gcyrc")
  undefSymbol(conf.symbols, "gcatomicarc")
  undefSymbol(conf.symbols, "nimSeqsV2")
  undefSymbol(conf.symbols, "nimV2")
@@ -615,10 +586,6 @@ proc processMemoryManagementOption(switch, arg: string, pass: TCmdLinePass,
      conf.selectedGC = gcOrc
      defineSymbol(conf.symbols, "gcorc")
      registerArcOrc(pass, conf)
-    of "yrc":
-      conf.selectedGC = gcYrc
-      defineSymbol(conf.symbols, "gcyrc")
-      registerArcOrc(pass, conf)
    of "atomicarc":
      conf.selectedGC = gcAtomicArc
      defineSymbol(conf.symbols, "gcatomicarc")
@@ -627,11 +594,7 @@ proc processMemoryManagementOption(switch, arg: string, pass: TCmdLinePass,
      conf.selectedGC = gcHooks
      defineSymbol(conf.symbols, "gchooks")
      incl conf.globalOptions, optSeqDestructors
-      # (The `arg` here is the mm MODE — "hooks" — so feeding it to an on/off
-      # switch made `--mm:hooks` fail outright with "'on' or 'off' expected, but
-      # 'hooks' found". The `incl` above is what that call was meant to do.
-      # Reachable only via the explicit switch: `--newruntime` sets
-      # `selectedGC` directly, which is why this stayed hidden.)
+      processOnOffSwitchG(conf, {optSeqDestructors}, arg, pass, info)
      if pass in {passCmd2, passPP}:
        defineSymbol(conf.symbols, "nimSeqsV2")
    of "go":
@@ -659,18 +622,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
                    conf: ConfigRef) =
  var key = ""
  var val = ""
-  # Record config-file switches so the `nim ic` driver can serialise them into a
-  # precompiled-config artifact and have its per-module child processes replay
-  # them instead of re-parsing the `nim.cfg` chain (and re-running `config.nims`
-  # in the VM) on every invocation. Only `passPP` (config-file) switches are
-  # captured; command-line switches are forwarded by the build graph as usual.
-  # Path-search switches are skipped: their net effect already lives in the
-  # resolved `searchPaths` the driver forwards as `--path`, and replaying their
-  # raw (often relative-to-config-dir) arguments here would misresolve.
-  if pass == passPP and switch.normalize notin
-      ["path", "p", "nimblepath", "lazypath", "excludepath",
-       "nonimblepath", "clearnimblepath", "nimcache"]:
-    conf.icConfigSwitches.add (switch, arg)
  case switch.normalize
  of "eval":
    expectArg(conf, switch, arg, pass, info)
@@ -723,14 +674,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
    conf.outDir = processPath(conf, arg, info, notRelativeToProj=true)
  of "usenimcache":
    processOnOffSwitchG(conf, {optUseNimcache}, arg, pass, info)
-  of "ideimports":
-    # nimsuggest: where the import closure comes from. IC is opt-in.
-    #   nif|on               load unchanged imports from precompiled NIF (cmdM)
-    #   source|off (default) recompile the whole closure from source (cmdCheck)
-    case arg.normalize
-    of "nif", "on", "": conf.ideImportsFromNif = true
-    of "source", "off": conf.ideImportsFromNif = false
-    else: localError(conf, info, "'--ideImports' expects 'nif' or 'source', got: '$1'" % arg)
  of "docseesrcurl":
    expectArg(conf, switch, arg, pass, info)
    conf.docSeeSrcUrl = arg
@@ -784,17 +727,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
    processMemoryManagementOption(switch, arg, pass, info, conf)
  of "mm":
    processMemoryManagementOption(switch, arg, pass, info, conf)
-  of "strings":
-    expectArg(conf, switch, arg, pass, info)
-    if pass in {passCmd2, passPP}:
-      case arg.normalize
-      of "default":
-        conf.selectedStrings = stringDefault
-      of "sso":
-        conf.selectedStrings = stringSso
-        defineSymbol(conf.symbols, "nimsso")
-      else:
-        localError(conf, info, errDefaultOrSsoExpectedButXFound % arg)
  of "warnings", "w":
    if processOnOffSwitchOrList(conf, {optWarns}, arg, pass, info): listWarnings(conf)
  of "warning": processSpecificNote(arg, wWarning, pass, info, switch, conf)
@@ -820,18 +752,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
      conf.globalOptions.excl optCDebug
    else:
      localError(conf, info, "expected native|gdb|on|off but found " & arg)
-  of "mangle":
-    case arg.normalize
-    of "nim":
-      conf.globalOptions.excl optItaniumMangle
-    of "cpp":
-      conf.globalOptions.incl optItaniumMangle
-    else:
-      localError(conf, info, "expected nim|cpp but found " & arg)
-  of "compress":
-    conf.globalOptions.incl optCompress
-  of "genbif":
-    processOnOffSwitchG(conf, {optGenBif}, arg, pass, info)
  of "g": # alias for --debugger:native
    conf.globalOptions.incl optCDebug
    conf.options.incl optLineDir
@@ -847,7 +767,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
  of "hotcodereloading":
    processOnOffSwitchG(conf, {optHotCodeReloading}, arg, pass, info)
    if conf.hcrOn:
-      warningDeprecated(conf, info, "hotCodeReloading is deprecated, see https://github.com/nim-lang/RFCs/issues/573 for further information")
      defineSymbol(conf.symbols, "hotcodereloading")
      defineSymbol(conf.symbols, "useNimRtl")
      # hardcoded linking with dynamic runtime for MSVC for smaller binaries
@@ -952,69 +871,14 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
    else: localError(conf, info, errOnOrOffExpectedButXFound % arg)
  of "noimportdoc":
    processOnOffSwitchG(conf, {optNoImportdoc}, arg, pass, info)
-  of "ismainmodule":
-    # `nim m` (IC) only: marks the single module being checked as the program's
-    # real entry point so that `isMainModule` and `when isMainModule:` resolve
-    # correctly even though every module is compiled with `sfMainModule` set.
-    conf.isMainModule = switchOn(arg)
-  of "icgroup":
-    # `nim m` only: register a module that belongs to the current strongly-
-    # connected import group, so it is compiled from source (not loaded from a
-    # precompiled NIF) and gets its own NIF written. `deps.nim` emits one
-    # `--icGroup:<path>` per member of a dependency cycle. The argument is an
-    # absolute .nim path produced by the dependency scanner.
-    expectArg(conf, switch, arg, pass, info)
-    if pass in {passCmd2, passPP}:
-      conf.icGroup.incl(canonicalizePath(conf, AbsoluteFile arg).string)
-  of "icproject":
-    # `nim m`/`nim nifc` only: the ORIGINAL project file (see options.icProject)
-    expectArg(conf, switch, arg, pass, info)
-    if pass in {passCmd2, passPP}:
-      conf.icProject = canonicalizePath(conf, AbsoluteFile arg).string
-  of "icpreparsedconfig":
-    # `nim m`/`nim nifc` only: path of the precompiled-config artifact (see
-    # options.icPreparsedConfig). Read in `passCmd1`, before `loadConfigs`, so
-    # config loading can replay it instead of re-parsing the `nim.cfg` chain.
-    expectArg(conf, switch, arg, pass, info)
-    conf.icPreparsedConfig = arg
-  of "icconfigout":
-    # `nim icconfig` only: where to write the precompiled config artifact (see
-    # options.icConfigOut). The `nim ic` driver spawns the producer with this.
-    expectArg(conf, switch, arg, pass, info)
-    conf.icConfigOut = arg
-  of "icbackendstage":
-    # `nim nifc` only: per-module backend stage, one of cg|merge|emit (see
-    # options.icBackendStage). Empty (switch unused) keeps the whole-program
-    # backend. Emitted by `deps.nim`'s backend build file.
-    expectArg(conf, switch, arg, pass, info)
-    if pass in {passCmd2, passPP}:
-      conf.icBackendStage = arg
-  of "icbackendmodule", "icbackendmodules":
-    # `nim nifc` only: the NIF module suffixes the lower/cg/emit stage operates
-    # on, comma-separated — the invocation's batch (see
-    # options.icBackendModules). The singular spelling is the same switch: a
-    # one-module batch is what the per-module fan-out passes.
-    expectArg(conf, switch, arg, pass, info)
-    if pass in {passCmd2, passPP}:
-      conf.icBackendModules = @[]
-      for suffix in arg.split(','):
-        if suffix.len > 0: conf.icBackendModules.add suffix
  of "import":
    expectArg(conf, switch, arg, pass, info)
    if pass in {passCmd2, passPP}:
-      let m = findModule(conf, arg, toFullPath(conf, info)).string
-      if m.len == 0:
-        localError(conf, info, "Cannot resolve filename: " & arg)
-      else:
-        conf.implicitImports.add(if arg.startsWith(stdPrefix): arg else: m)
+      conf.implicitImports.add findModule(conf, arg, toFullPath(conf, info)).string
  of "include":
    expectArg(conf, switch, arg, pass, info)
    if pass in {passCmd2, passPP}:
-      let m = findModule(conf, arg, toFullPath(conf, info)).string
-      if m.len == 0:
-        localError(conf, info, "Cannot resolve filename: " & arg)
-      else:
-        conf.implicitIncludes.add m
+      conf.implicitIncludes.add findModule(conf, arg, toFullPath(conf, info)).string
  of "listcmd":
    processOnOffSwitchG(conf, {optListCmd}, arg, pass, info)
  of "asm":
@@ -1046,14 +910,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
    expectArg(conf, switch, arg, pass, info)
    var value: int = 10_000_000
    discard parseSaturatedNatural(arg, value)
-    if value <= 0: localError(conf, info, "maxLoopIterationsVM must be a positive integer greater than zero")
+    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.
@@ -1063,10 +921,6 @@ 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)
@@ -1096,17 +950,11 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
    expectNoArg(conf, switch, arg, pass, info)
    helpOnError(conf, pass)
  of "symbolfiles", "incremental", "ic":
-    if pass in {passCmd2, passPP} and switch.normalize == "symbolfiles":
-      deprecatedAlias(switch, "incremental")
+    if switch.normalize == "symbolfiles": deprecatedAlias(switch, "incremental")
      # xxx maybe also ic, since not in help?
-    # `--ic:on` is read in passCmd1 too: `nim.nim` decides BEFORE config loading
-    # whether this run is an IC driver (`ensureIcConfig` must produce the
-    # precompiled config the driver itself then replays), and passCmd1 is the
-    # only pass that has run by then.
-    if pass in {passCmd1, passCmd2, passPP}:
+    if pass in {passCmd2, passPP}:
      case arg.normalize
-      of "on": conf.ic = true
-      of "legacy": conf.symbolFiles = v2Sf
+      of "on": conf.symbolFiles = v2Sf
      of "off": conf.symbolFiles = disabledSf
      of "writeonly": conf.symbolFiles = writeOnlySf
      of "readonly": conf.symbolFiles = readOnlySf
@@ -1214,9 +1062,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
  of "shownonexports":
    expectNoArg(conf, switch, arg, pass, info)
    showNonExportedFields(conf)
-  of "raw":
-    expectNoArg(conf, switch, arg, pass, info)
-    docRawOutput(conf)
  of "exceptions":
    case arg.normalize
    of "cpp": conf.exc = excCpp
@@ -1248,10 +1093,9 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
      defineSymbol(conf.symbols, "nimSeqsV2")
  of "stylecheck":
    case arg.normalize
-    of "off": conf.globalOptions = conf.globalOptions - {optStyleHint, optStyleError, optStyleWarning}
-    of "hint": conf.globalOptions = conf.globalOptions + {optStyleHint} - {optStyleError, optStyleWarning}
-    of "warning": conf.globalOptions = conf.globalOptions + {optStyleWarning} - {optStyleHint, optStyleError}
-    of "error": conf.globalOptions = conf.globalOptions + {optStyleError} - {optStyleHint, optStyleWarning}
+    of "off": conf.globalOptions = conf.globalOptions - {optStyleHint, optStyleError}
+    of "hint": conf.globalOptions = conf.globalOptions + {optStyleHint} - {optStyleError}
+    of "error": conf.globalOptions = conf.globalOptions + {optStyleError}
    of "usages": conf.globalOptions.incl optStyleUsages
    else: localError(conf, info, errOffHintsError % arg)
  of "showallmismatches":
@@ -1341,16 +1185,8 @@ proc processArgument*(pass: TCmdLinePass; p: OptParser;
      # support UNIX style filenames everywhere for portable build scripts:
      if config.projectName.len == 0:
        config.projectName = unixToNativePath(p.key)
-      if config.cmd == cmdTrack:
-        # `nim track PROJ --def:...`: unlike a normal command (where everything
-        # after the project file is passed to the compiled program), `track`
-        # accepts its IDE-query switches AFTER the project — the natural,
-        # nimsuggest-like invocation form. So don't swallow the rest of the line
-        # into `arguments`; keep parsing the remaining tokens as switches.
-        result = false
-      else:
-        config.arguments = cmdLineRest(p)
-        result = true
+      config.arguments = cmdLineRest(p)
+      result = true
    else:
      result = false
  inc argsCount
--- a/compiler/concepts.nim
+++ b/compiler/concepts.nim
@@ -11,16 +11,15 @@
 ## for details. Note this is a first implementation and only the "Concept matching"
 ## section has been implemented.

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

-import std/sets
+import std/intsets

 when defined(nimPreviewSlimSystem):
  import std/assertions

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

 ## Code dealing with Concept declarations
 ## --------------------------------------
@@ -30,7 +29,7 @@ proc declareSelf(c: PContext; info: TLineInfo) =
  let ow = getCurrOwner(c)
  let s = newSym(skType, getIdent(c.cache, "Self"), c.idgen, ow, info)
  s.typ = newType(tyTypeDesc, c.idgen, ow)
-  s.typ.incl {tfUnresolved, tfPacked}
+  s.typ.flags.incl {tfUnresolved, tfPacked}
  s.typ.add newType(tyEmpty, c.idgen, ow)
  addDecl(c, s, info)

@@ -71,277 +70,88 @@ proc semConceptDeclaration*(c: PContext; n: PNode): PNode =
 ## ----------------

 type
-  MatchFlags* = enum
-    mfDontBind  # Do not export bindings from the concept match
-    mfBindGenericParam  # Export inferred invocation parameters despite mfDontBind
-    mfCheckGeneric  # formal <- formal comparison as opposed to formal <- operand
-
-  ConceptTypePair = tuple[conceptId, typeId: ItemId]
-    ## Pair of (concept type id, implementation type id) used for cycle detection
-
  MatchCon = object ## Context we pass around during concept matching.
-    bindings: LayeredIdTable
-    marker: HashSet[ConceptTypePair] ## Tracks (concept, type) pairs being checked to detect cycles.
+    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
-    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 not key.elementType.isNil 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
-
-  # Handle self-referential concepts: when a concept references itself in its body
-  # (e.g., `A = concept; proc test(x: Self, y: A)`), the inner type A has n=nil.
-  # We detect this by checking if the concept has the same symbol name as the
-  # one we're currently matching and has no body (n=nil).
-  if concpt.n.isNil:
-    if concpt.sym != nil and m.concpt.sym != nil and
-       concpt.sym == m.concpt.sym:
-      # Self-reference: check if potentialImpl matches what we're already checking
-      return potentialImpl.id == m.potentialImplementation.id
-    # Concept without body that's not a self-reference - cannot match
-    return false
-
-  # Cycle detection: track (concept, type) pairs to prevent infinite recursion.
-  # Returns true on cycle (coinductive semantics) to support co-dependent concepts.
-  let pair: ConceptTypePair = (concpt.bindingId, potentialImpl.bindingId)
-  if pair in m.marker:
-    return true
-  m.marker.incl pair
-
-  var efPot = potentialImpl
-  if potentialImpl.isSelf:
-    if m.concpt.n == concpt.n:
-      m.marker.excl pair
-      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
-  result = processConcept(c, concpt, invocation, oldBindings, m)
-  m.potentialImplementation = oldPotentialImplementation
-  m.concpt = oldConcept
-  m.bindings = oldBindings
-  m.marker.excl pair
-
-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
-  var match = false
-  for fdef in fn:
-    for ia, ndef in an:
-      match = cmpConceptDefs(c, fdef, ndef, m)
-      if match:
-        break
-    if not match:
-      return mkNoMatch
-  return mkSubset
-
-proc isObjectSubtype(f, a: PType): bool =
-  var t = a
-  result = false
-  while t != nil:
-    t = t.baseClass
-    if t == nil:
-      break
-    t = t.skipTypes({tyPtr,tyRef})
-    if t == nil:
-      break
-    if t.kind != tyObject:
-      break
-    if sameObjectTypes(f, t):
-      result = true
-      break
-
-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.isSelf:
-    if m.magic in {mArrPut, mArrGet}:
-      return false
-    a = m.potentialImplementation
-  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)
  of tyTypeDesc:
    if isSelf(f):
-      if m.magic in {mArrPut, mArrGet}:
-        if m.potentialImplementation.reduceToBase.kind in arrPutGetMagicApplies:
-          bindParam(c, m, a, last m.potentialImplementation)
+      #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 and f.hasElementType == a.hasElementType:
+        if f.hasElementType:
+          result = matchType(c, f.elementType, a.elementType, m)
+        else:
+          result = true # both lack it
+      else:
+        result = false
+
+  of tyGenericInvocation:
+    result = false
+    if a.kind == tyGenericInst and a.genericHead.kind == tyGenericBody:
+      if sameType(f.genericHead, a.genericHead) and f.kidsLen == a.kidsLen-1:
+        for i in FirstGenericParamAt ..< f.kidsLen:
+          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.hasElementType and f.elementType.kind != tyNone:
+          # also check the generic's constraints:
+          let oldLen = m.inferred.len
+          result = matchType(c, f.elementType, 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, last ak))
+          result = true
+        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 = matchType(c, a.skipTypes(ignorableForArgType), m.potentialImplementation, m)
-    else:
-      if a.kind == tyTypeDesc:
-        if not(a.hasElementType) or a.elementType.kind == tyNone:
-          result = true
-        elif f.hasElementType:
-          result = matchType(c, f.elementType, a.elementType, m)
+        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.
@@ -349,136 +159,70 @@ proc matchType(c: PContext; fo, ao: PType; m: var MatchCon): bool =
      result = matchType(c, f.elementType, a.elementType, 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)
    else:
-      if a.kind == tyGenericInst:
-        # tyOr does this to generic typeclasses
-        result = a.base.sym == f.sym
-      else:
-        result = sameType(f, a)
-      if not result and f.kind == tyObject and a.kind == tyObject:
-        result = isObjectSubtype(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:
-        if f.base.kind == tyNone:
-          result = true
-        elif f.kidsLen == ak.kidsLen:
-          result = matchKids(c, f, ak, m)
-  of tyGenericInvocation, tyGenericInst:
+       (ak.kind == tyGenericParam and ak.hasElementType and ak.elementType.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:
+    # ^ XXX Rewrite this logic, it's more complex than it needs to be.
    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
-    elif f.kind == tyGenericInvocation:
-      # bind potential generic constraints into body
-      let body = f.base
-      for i in 1 ..< len(f):
-        bindParam(c,m,body[i-1], f[i])
-      result = matchType(c, body, a, m)
-    else: # tyGenericInst
-      result = matchType(c, f.last, a, m)
-  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.kidsLen == ak.kidsLen:
+      for i in 0..<ak.kidsLen:
+        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()
+      for ff in f.kids:
+        for aa in a.kids:
+          let oldLenB = m.inferred.len
          let r = matchType(c, ff, aa, m)
          if r:
            inc covered
            break
-          m.bindings.setToPreviousLayer()
+          m.inferred.setLen oldLenB

      result = covered >= a.kidsLen
+      if not result:
+        m.inferred.setLen oldLen
    else:
+      result = false
      for ff in f.kids:
-        m.bindings = m.bindings.newTypeMapLayer()
        result = matchType(c, ff, a, m)
        if result: break # and remember the binding!
-        m.bindings.setToPreviousLayer()
-  of tySet:
-    result = false
-    if a.kind == tySet:
+        m.inferred.setLen oldLen
+  of tyNot:
+    if a.kind == tyNot:
      result = matchType(c, f.elementType, a.elementType, m)
+    else:
+      let oldLen = m.inferred.len
+      result = not matchType(c, f.elementType, 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
@@ -488,38 +232,30 @@ 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.returnType, candidate.typ.returnType, m):
+    m.inferred.setLen oldLen
    return false

  # all other parameters have to be optional parameters:
@@ -527,7 +263,7 @@ 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
@@ -535,14 +271,12 @@ 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'
@@ -575,76 +309,7 @@ proc conceptMatchNode(c: PContext; n: PNode; m: var MatchCon): bool =
    # error was reported earlier.
    result = false

-proc resolvedBinding(c: PContext; t: PType; m: MatchCon): PType =
-  ## An inferred concept parameter can refer to an implementation-local
-  ## generic parameter, for example `Elem[Impl.T]`. Resolve it while the
-  ## matcher's private bindings (`Impl.T -> int`) are still available.
-  if t.containsUnresolvedType:
-    prepareMetatypeForSigmatch(c, m.bindings, m.concpt.sym.info, t)
-  else:
-    t
-
-proc fixBindings(c: PContext; 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:
-        let resolved = resolvedBinding(c, found, m)
-        when logBindings: echo "Invocation bind: ", thisSym, " ", resolved
-        bindings.put(thisSym, resolved)
-    
-    # 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 fixConstraintBindings(c: PContext; bindings: var LayeredIdTable;
-                           invocation: PType; m: MatchCon) =
-  ## Propagates only the dependent parameters of a concept constraint. The
-  ## concept itself and its private matcher bindings must remain unbound so
-  ## that independent constraints using the same concept don't get coupled.
-  if invocation != nil and invocation.kind == tyGenericInvocation:
-    let genBody = invocation.base
-    assert genBody.kind == tyGenericBody
-    for i in FirstGenericParamAt ..< invocation.kidsLen:
-      if lookup(bindings, invocation[i]) == nil:
-        let boundValue = m.bindings.lookup(genBody[i - 1])
-        if boundValue != nil:
-          bindings.put(invocation[i], resolvedBinding(c, boundValue, m))
-
-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:
-    if mfDontBind notin m.flags:
-      fixBindings(c, bindings, concpt, invocation, m)
-    elif mfBindGenericParam in m.flags:
-      fixConstraintBindings(c, bindings, 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 TypeMapping; 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
  ## concept's requirements. If so, we return true and fill the 'bindings' with pairs of
@@ -653,16 +318,26 @@ proc conceptMatch*(c: PContext; concpt, arg: PType; bindings: var LayeredIdTable
  ## `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, marker: initHashSet[ConceptTypePair]())
-  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.kidsLen == arg.kidsLen-1:
+      # bind even more generic parameters
+      assert invocation.kind == tyGenericInvocation
+      for i in FirstGenericParamAt ..< invocation.kidsLen:
+        bindings.idTablePut(invocation[i], arg[i])
--- a/compiler/condsyms.nim
+++ b/compiler/condsyms.nim
@@ -159,21 +159,11 @@ proc initDefines*(symbols: StringTableRef) =
  defineSymbol("nimHasEnsureMove")
  defineSymbol("nimHasNoReturnError")

-  defineSymbol("nimUseStrictDefs") # deadcode
+  defineSymbol("nimUseStrictDefs")
  defineSymbol("nimHasNolineTooLong")

  defineSymbol("nimHasCastExtendedVm")
  defineSymbol("nimHasWarnStdPrefix")

  defineSymbol("nimHasVtables")
-  defineSymbol("nimHasGenericsOpenSym2")
-  defineSymbol("nimHasGenericsOpenSym3")
  defineSymbol("nimHasJsNoLambdaLifting")
-  defineSymbol("nimHasDefaultFloatRoundtrip")
-  defineSymbol("nimHasXorSet")
-
-  defineSymbol("nimHasSetLengthSeqUninitMagic")
-  defineSymbol("nimHasPreviewDuplicateModuleError")
-
-  defineSymbol("nimHasImplicitRangeConversion")
-
--- a/compiler/deps.nim
+++ b/compiler/deps.nim
--- a/compiler/dfa.nim
+++ b/compiler/dfa.nim
@@ -439,8 +439,8 @@ 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)
@@ -454,7 +454,7 @@ proc gen(c: var Con; n: PNode) =
  of nkPragmaBlock: gen(c, n.lastSon)
  of nkDiscardStmt, nkObjDownConv, nkObjUpConv, nkStringToCString, nkCStringToString:
    gen(c, n[0])
-  of nkConv, nkExprColonExpr, nkExprEqExpr, PathKinds1:
+  of nkConv, nkExprColonExpr, nkExprEqExpr, nkCast, PathKinds1:
    gen(c, n[1])
  of nkVarSection, nkLetSection: genVarSection(c, n)
  of nkDefer: raiseAssert "dfa construction pass requires the elimination of 'defer'"
@@ -483,7 +483,7 @@ proc constructCfg*(s: PSym; body: PNode; root: PSym): ControlFlowGraph =
    gen(c, body)
    if root.kind == skResult:
      genImplicitReturn(c)
-  when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc) or defined(gcYrc):
+  when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc):
    result = c.code # will move
  else:
    shallowCopy(result, c.code)
--- a/compiler/docgen.nim
+++ b/compiler/docgen.nim
@@ -19,7 +19,7 @@ import
  wordrecg, syntaxes, renderer, lexer,
  packages/docutils/[rst, rstidx, rstgen, dochelpers],
  trees, types,
-  typesrenderer, lineinfos,
+  typesrenderer, astalgo, lineinfos,
  pathutils, nimpaths, renderverbatim, packages
 import packages/docutils/rstast except FileIndex, TLineInfo

@@ -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)
@@ -148,7 +148,7 @@ proc cmpDecimalsIgnoreCase(a, b: string): int =
        limitB = iB
      while limitA < aLen and isDigit(a[limitA]): inc limitA
      while limitB < bLen and isDigit(b[limitB]): inc limitB
-      var pos = max(limitA-iA, limitB-iB)
+      var pos = max(limitA-iA, limitB-iA)
      while pos > 0:
        if limitA-pos < iA:  # digit in `a` is 0 effectively
          result = ord('0') - ord(b[limitB-pos])
@@ -425,11 +425,14 @@ template dispA(conf: ConfigRef; dest: var string, xml, tex: string,
  if not conf.isLatexCmd: dest.addf(xml, args)
  else: dest.addf(tex, args)

+proc getVarIdx(varnames: openArray[string], id: string): int =
+  for i in 0..high(varnames):
+    if cmpIgnoreStyle(varnames[i], id) == 0:
+      return i
+  result = -1
+
 proc genComment(d: PDoc, n: PNode): PRstNode =
  if n.comment.len > 0:
-    if optDocRaw in d.conf.globalOptions:
-      return newRstLeaf(n.comment)
-
    d.sharedState.currFileIdx = addRstFileIndex(d, n.info)
    try:
      result = parseRst(n.comment,
@@ -534,11 +537,10 @@ proc nodeToHighlightedHtml(d: PDoc; n: PNode; result: var string;
      elif s != nil and s.kind in {skType, skVar, skLet, skConst} and
           sfExported in s.flags and s.owner != nil and
           belongsToProjectPackage(d.conf, s.owner) and d.target == outHtml:
-        let href = (if d.module == s.owner: ""
-            else: externalDep(d, s.owner).changeFileExt("html")
-          ) & "#" & literal
-        result.addf "<a href=\"$1\"><span class=\"Identifier\">$2</span></a>",
-            [href, escLit]
+        let external = externalDep(d, s.owner)
+        result.addf "<a href=\"$1#$2\"><span class=\"Identifier\">$3</span></a>",
+          [changeFileExt(external, "html"), literal,
+           escLit]
      else:
        dispA(d.conf, result, "<span class=\"Identifier\">$1</span>",
              "\\spanIdentifier{$1}", [escLit])
@@ -828,8 +830,8 @@ proc getName(n: PNode): string =
  of nkAccQuoted:
    result = "`"
    for i in 0..<n.len: result.add(getName(n[i]))
-    result.add('`')
-  of nkOpenSymChoice, nkClosedSymChoice, nkOpenSym:
+    result = "`"
+  of nkOpenSymChoice, nkClosedSymChoice:
    result = getName(n[0])
  else:
    result = ""
@@ -847,7 +849,7 @@ proc getNameIdent(cache: IdentCache; n: PNode): PIdent =
    var r = ""
    for i in 0..<n.len: r.add(getNameIdent(cache, n[i]).s)
    result = getIdent(cache, r)
-  of nkOpenSymChoice, nkClosedSymChoice, nkOpenSym:
+  of nkOpenSymChoice, nkClosedSymChoice:
    result = getNameIdent(cache, n[0])
  else:
    result = nil
@@ -861,7 +863,7 @@ proc getRstName(n: PNode): PRstNode =
  of nkAccQuoted:
    result = getRstName(n[0])
    for i in 1..<n.len: result.text.add(getRstName(n[i]).text)
-  of nkOpenSymChoice, nkClosedSymChoice, nkOpenSym:
+  of nkOpenSymChoice, nkClosedSymChoice:
    result = getRstName(n[0])
  else:
    result = nil
@@ -1174,12 +1176,8 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
                   "col": %n.info.col}
  )
  if comm != nil:
-    if optDocRaw in d.conf.globalOptions:
-      result.json["description"] = %comm.text
-    else:
-      result.rst = comm
-      result.rstField = "description"
-
+    result.rst = comm
+    result.rstField = "description"
  if r.buf.len > 0:
    result.json["code"] = %r.buf
  if k in routineKinds:
@@ -1208,7 +1206,7 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
        var param = %{"name": %($genericParam)}
        if genericParam.sym.typ.len > 0:
          param["types"] = newJArray()
-          param["types"] = %($genericParam.sym.typ.elementType)
+        param["types"].add %($genericParam.sym.typ.elementType)
        result.json["signature"]["genericParams"].add param
  if optGenIndex in d.conf.globalOptions:
    genItem(d, n, nameNode, k, kForceExport)
@@ -1408,19 +1406,16 @@ proc generateDoc*(d: PDoc, n, orig: PNode, config: ConfigRef, docFlags: DocFlags
    for it in n: traceDeps(d, it)
  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
+      # bug #23051; don't generate documentation for exported symbols again
+      if it.kind == nkSym and sfExported notin it.sym.flags:
+        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])
  of nkCallKinds:
-    var comm = default(ItemPre)
+    var comm: ItemPre = default(ItemPre)
    getAllRunnableExamples(d, n, comm)
    if comm.len != 0: d.modDescPre.add(comm)
  else: discard
@@ -1894,9 +1889,6 @@ proc commandJson*(cache: IdentCache, conf: ConfigRef) =
  else:
    #echo getOutFile(gProjectFull, JsonExt)
    let filename = getOutFile(conf, RelativeFile conf.projectName, JsonExt)
-    conf.outFile = filename.relativeTo(conf.outDir)
-    let dir = filename.splitFile.dir
-    createDir(dir)
    try:
      writeFile(filename, content)
    except IOError:
@@ -1917,10 +1909,8 @@ proc commandTags*(cache: IdentCache, conf: ConfigRef) =
  if optStdout in d.conf.globalOptions:
    write(stdout, content)
  else:
+    #echo getOutFile(gProjectFull, TagsExt)
    let filename = getOutFile(conf, RelativeFile conf.projectName, TagsExt)
-    conf.outFile = filename.relativeTo(conf.outDir)
-    let dir = filename.splitFile.dir
-    createDir(dir)
    try:
      writeFile(filename, content)
    except IOError:
--- a/compiler/docgen2.nim
+++ b/compiler/docgen2.nim
@@ -29,6 +29,7 @@ proc shouldProcess(g: PGen): bool =
 template closeImpl(body: untyped) {.dirty.} =
  var g = PGen(p)
  let useWarning = sfMainModule notin g.module.flags
+  let groupedToc = true
  if shouldProcess(g):
    finishGenerateDoc(g.doc)
    body
@@ -40,7 +41,7 @@ template closeImpl(body: untyped) {.dirty.} =
 proc closeDoc*(graph: ModuleGraph; p: PPassContext, n: PNode): PNode =
  result = nil
  closeImpl:
-    writeOutput(g.doc, useWarning, true)
+    writeOutput(g.doc, useWarning, groupedToc)

 proc closeJson*(graph: ModuleGraph; p: PPassContext, n: PNode): PNode =
  result = nil
--- a/compiler/enumtostr.nim
+++ b/compiler/enumtostr.nim
@@ -14,7 +14,7 @@ proc genEnumToStrProc*(t: PType; info: TLineInfo; g: ModuleGraph; idgen: IdGener
  let res = newSym(skResult, getIdent(g.cache, "result"), idgen, result, info)
  res.typ = getSysType(g, info, tyString)

-  result.typ = newType(tyProc, idgen, result)
+  result.typ = newType(tyProc, idgen, t.owner)
  result.typ.n = newNodeI(nkFormalParams, info)
  rawAddSon(result.typ, res.typ)
  result.typ.n.add newNodeI(nkEffectList, info)
@@ -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)

@@ -47,5 +43,68 @@ proc genEnumToStrProc*(t: PType; info: TLineInfo; g: ModuleGraph; idgen: IdGener
  n[bodyPos] = body
  n[resultPos] = newSymNode(res)
  result.ast = n
-  incl result.flagsImpl, {sfFromGeneric, sfNeverRaises}
-  setHookDisamb(g, result, "$enumtostr", t)
+  incl result.flags, sfFromGeneric
+  incl result.flags, sfNeverRaises
+
+proc searchObjCaseImpl(obj: PNode; field: PSym): PNode =
+  case obj.kind
+  of nkSym:
+    result = nil
+  of nkElse, nkOfBranch:
+    result = searchObjCaseImpl(obj.lastSon, field)
+  else:
+    if obj.kind == nkRecCase and obj[0].kind == nkSym and obj[0].sym == field:
+      result = obj
+    else:
+      result = nil
+      for x in obj:
+        result = searchObjCaseImpl(x, field)
+        if result != nil: break
+
+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)
+  doAssert result != nil
+
+proc genCaseObjDiscMapping*(t: PType; field: PSym; info: TLineInfo; g: ModuleGraph; idgen: IdGenerator): PSym =
+  result = newSym(skProc, getIdent(g.cache, "objDiscMapping"), idgen, t.owner, info)
+
+  let dest = newSym(skParam, getIdent(g.cache, "e"), idgen, result, info)
+  dest.typ = field.typ
+
+  let res = newSym(skResult, getIdent(g.cache, "result"), idgen, result, info)
+  res.typ = getSysType(g, info, tyUInt8)
+
+  result.typ = newType(tyProc, idgen, t.owner)
+  result.typ.n = newNodeI(nkFormalParams, info)
+  rawAddSon(result.typ, res.typ)
+  result.typ.n.add newNodeI(nkEffectList, info)
+
+  result.typ.addParam dest
+
+  var body = newNodeI(nkStmtList, info)
+  var caseStmt = newNodeI(nkCaseStmt, info)
+  caseStmt.add(newSymNode dest)
+
+  let subObj = searchObjCase(t, field)
+  for i in 1..<subObj.len:
+    let ofBranch = subObj[i]
+    var newBranch = newNodeI(ofBranch.kind, ofBranch.info)
+    for j in 0..<ofBranch.len-1:
+      newBranch.add ofBranch[j]
+
+    newBranch.add newTree(nkStmtList, newTree(nkFastAsgn, newSymNode(res), newIntNode(nkInt8Lit, i)))
+    caseStmt.add newBranch
+
+  body.add(caseStmt)
+
+  var n = newNodeI(nkProcDef, info, bodyPos+2)
+  for i in 0..<n.len: n[i] = newNodeI(nkEmpty, info)
+  n[namePos] = newSymNode(result)
+  n[paramsPos] = result.typ.n
+  n[bodyPos] = body
+  n[resultPos] = newSymNode(res)
+  result.ast = n
+  incl result.flags, sfFromGeneric
+  incl result.flags, sfNeverRaises
--- a/compiler/evaltempl.nim
+++ b/compiler/evaltempl.nim
@@ -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)

@@ -64,7 +51,7 @@ proc evalTemplateAux(templ, actual: PNode, c: var TemplCtx, result: PNode) =
        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)
--- a/compiler/expanddefaults.nim
+++ b/compiler/expanddefaults.nim
@@ -125,7 +125,7 @@ proc expandDefault(t: PType; info: TLineInfo): PNode =
  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
@@ -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: "",
@@ -257,8 +253,8 @@ 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",
@@ -341,7 +337,7 @@ 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, backendNif: discard
+  of backendC: discard
  of backendInvalid:
    # during parsing of cfg files; we don't know the backend yet, no point in
    # guessing wrong thing
@@ -474,11 +470,6 @@ 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 +777,7 @@ 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"
@@ -810,59 +801,6 @@ template tryExceptOSErrorMessage(conf: ConfigRef; errorPrefix: string = "", body
        (ose.msg & " " & $ose.errorCode))
    raise

-proc createMacAppBundle(conf: ConfigRef; exefile: AbsoluteFile) =
-  let (dir, name, _) = splitFile(exefile.string)
-  let appBundleName = name & ".app"
-  let appBundlePath = dir / appBundleName
-  let contentsPath = appBundlePath / "Contents"
-  let macosPath = contentsPath / "MacOS"
-
-  createDir(macosPath)
-
-  let bundleExePath = macosPath / name
-  copyFileWithPermissions(exefile.string, bundleExePath)
-
-  let infoPlistPath = contentsPath / "Info.plist"
-
-  proc xmlEscape(s: string): string =
-    result = newStringOfCap(s.len)
-    for c in items(s):
-      case c:
-      of '<': result.add("&lt;")
-      of '>': result.add("&gt;")
-      of '&': result.add("&amp;")
-      of '"': result.add("&quot;")
-      of '\'': result.add("&apos;")
-      else:
-        if ord(c) < 32:
-          result.add("&#" & $ord(c) & ';')
-        else:
-          result.add(c)
-
-  let escapedName = xmlEscape(name)
-  let infoPlistContent = """<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
-<plist version="1.0">
-<dict>
-  <key>CFBundleExecutable</key>
-  <string>$1</string>
-  <key>CFBundleIdentifier</key>
-  <string>com.nim.$1</string>
-  <key>CFBundleName</key>
-  <string>$1</string>
-  <key>CFBundlePackageType</key>
-  <string>APPL</string>
-  <key>LSUIElement</key>
-  <string>1</string>
-</dict>
-</plist>""" % [escapedName]
-
-  writeFile(infoPlistPath, infoPlistContent)
-
-  removeFile(exefile.string)
-
-  rawMessage(conf, hintUserRaw, "Created Mac app bundle: " & appBundlePath)
-
 proc getExtraCmds(conf: ConfigRef; output: AbsoluteFile): seq[string] =
  result = @[]
  when defined(macosx):
@@ -1047,10 +985,6 @@ proc callCCompiler*(conf: ConfigRef) =
        preventLinkCmdMaxCmdLen(conf, linkCmd)
        for cmd in extraCmds:
          execExternalProgram(conf, cmd, hintExecuting)
-        # create Mac app bundle for GUI apps on macOS
-        when defined(macosx):
-          if conf.globalOptions * {optGenGuiApp, optGenDynLib, optGenStaticLib} == {optGenGuiApp}:
-            createMacAppBundle(conf, mainOutput)
  else:
    linkCmd = ""
  if optGenScript in conf.globalOptions:
@@ -1066,11 +1000,10 @@ 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
@@ -1114,8 +1047,6 @@ proc writeJsonBuildInstructions*(conf: ConfigRef; deps: StringTableRef) =
          bcache.depfiles.add (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)

@@ -1136,8 +1067,6 @@ 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)
@@ -1154,7 +1083,7 @@ 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
@@ -46,7 +46,7 @@ proc isLocation(n: PNode): bool = not n.isValue

 proc isLet(n: PNode): bool =
  if n.kind == nkSym:
-    if n.sym.kind in {skLet, skConst, skTemp, skForVar}: # guard immutable variables
+    if n.sym.kind in {skLet, skTemp, skForVar}:
      result = true
    elif n.sym.kind == skParam and skipTypes(n.sym.typ,
                                             abstractInst).kind notin {tyVar}:
@@ -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/hlo.nim
+++ b/compiler/hlo.nim
@@ -10,7 +10,7 @@
 # This include implements the high level optimization pass.
 # included from sem.nim

-proc hlo(c: PContext, n: PNode, loopDetector: int): PNode
+proc hlo(c: PContext, n: PNode): PNode

 proc evalPattern(c: PContext, n, orig: PNode): PNode =
  internalAssert c.config, n.kind == nkCall and n[0].kind == nkSym
@@ -61,11 +61,10 @@ proc applyPatterns(c: PContext, n: PNode): PNode =
        # activate this pattern again:
        c.patterns[i] = pattern

-proc hlo(c: PContext, n: PNode, loopDetector: int): PNode =
+proc hlo(c: PContext, n: PNode): PNode =
+  inc(c.hloLoopDetector)
  # simply stop and do not perform any further transformations:
-  if loopDetector > 300:
-    message(c.config, n.info, warnUser, "term rewrite macro instantiation too nested")
-    return n
+  if c.hloLoopDetector > 300: return n
  case n.kind
  of nkMacroDef, nkTemplateDef, procDefs:
    # already processed (special cases in semstmts.nim)
@@ -81,7 +80,7 @@ proc hlo(c: PContext, n: PNode, loopDetector: int): PNode =
      # no optimization applied, try subtrees:
      for i in 0..<result.safeLen:
        let a = result[i]
-        let h = hlo(c, a, loopDetector)
+        let h = hlo(c, a)
        if h != a: result[i] = h
    else:
      # perform type checking, so that the replacement still fits:
@@ -91,15 +90,17 @@ proc hlo(c: PContext, n: PNode, loopDetector: int): PNode =
        result = fitNode(c, n.typ, result, n.info)
      # optimization has been applied so check again:
      result = commonOptimizations(c.graph, c.idgen, c.module, result)
-      result = hlo(c, result, loopDetector + 1)
+      result = hlo(c, result)
      result = commonOptimizations(c.graph, c.idgen, c.module, result)

 proc hloBody(c: PContext, n: PNode): PNode =
  # fast exit:
  if c.patterns.len == 0 or optTrMacros notin c.config.options: return n
-  result = hlo(c, n, 0)
+  c.hloLoopDetector = 0
+  result = hlo(c, n)

 proc hloStmt(c: PContext, n: PNode): PNode =
  # fast exit:
  if c.patterns.len == 0 or optTrMacros notin c.config.options: return n
-  result = hlo(c, n, 0)
+  c.hloLoopDetector = 0
+  result = hlo(c, n)
--- a/compiler/ic/bitabs.nim
+++ b/compiler/ic/bitabs.nim
@@ -0,0 +1,178 @@
+## A BiTable is a table that can be seen as an optimized pair
+## of `(Table[LitId, Val], Table[Val, LitId])`.
+
+import std/hashes
+import rodfiles
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+type
+  LitId* = distinct uint32
+
+  BiTable*[T] = object
+    vals: seq[T] # indexed by LitId
+    keys: seq[LitId]  # indexed by hash(val)
+
+proc initBiTable*[T](): BiTable[T] = BiTable[T](vals: @[], keys: @[])
+
+proc nextTry(h, maxHash: Hash): Hash {.inline.} =
+  result = (h + 1) and maxHash
+
+template maxHash(t): untyped = high(t.keys)
+template isFilled(x: LitId): bool = x.uint32 > 0'u32
+
+proc `$`*(x: LitId): string {.borrow.}
+proc `<`*(x, y: LitId): bool {.borrow.}
+proc `<=`*(x, y: LitId): bool {.borrow.}
+proc `==`*(x, y: LitId): bool {.borrow.}
+proc hash*(x: LitId): Hash {.borrow.}
+
+
+proc len*[T](t: BiTable[T]): int = t.vals.len
+
+proc mustRehash(length, counter: int): bool {.inline.} =
+  assert(length > counter)
+  result = (length * 2 < counter * 3) or (length - counter < 4)
+
+const
+  idStart = 1
+
+template idToIdx(x: LitId): int = x.int - idStart
+
+proc hasLitId*[T](t: BiTable[T]; x: LitId): bool =
+  let idx = idToIdx(x)
+  result = idx >= 0 and idx < t.vals.len
+
+proc enlarge[T](t: var BiTable[T]) =
+  var n: seq[LitId]
+  newSeq(n, len(t.keys) * 2)
+  swap(t.keys, n)
+  for i in 0..high(n):
+    let eh = n[i]
+    if isFilled(eh):
+      var j = hash(t.vals[idToIdx eh]) and maxHash(t)
+      while isFilled(t.keys[j]):
+        j = nextTry(j, maxHash(t))
+      t.keys[j] = move n[i]
+
+proc getKeyId*[T](t: BiTable[T]; v: T): LitId =
+  let origH = hash(v)
+  var h = origH and maxHash(t)
+  if t.keys.len != 0:
+    while true:
+      let litId = t.keys[h]
+      if not isFilled(litId): break
+      if t.vals[idToIdx t.keys[h]] == v: return litId
+      h = nextTry(h, maxHash(t))
+  return LitId(0)
+
+proc getOrIncl*[T](t: var BiTable[T]; v: T): LitId =
+  let origH = hash(v)
+  var h = origH and maxHash(t)
+  if t.keys.len != 0:
+    while true:
+      let litId = t.keys[h]
+      if not isFilled(litId): break
+      if t.vals[idToIdx t.keys[h]] == v: return litId
+      h = nextTry(h, maxHash(t))
+    # not found, we need to insert it:
+    if mustRehash(t.keys.len, t.vals.len):
+      enlarge(t)
+      # recompute where to insert:
+      h = origH and maxHash(t)
+      while true:
+        let litId = t.keys[h]
+        if not isFilled(litId): break
+        h = nextTry(h, maxHash(t))
+  else:
+    setLen(t.keys, 16)
+    h = origH and maxHash(t)
+
+  result = LitId(t.vals.len + idStart)
+  t.keys[h] = result
+  t.vals.add v
+
+
+proc `[]`*[T](t: var BiTable[T]; litId: LitId): var T {.inline.} =
+  let idx = idToIdx litId
+  assert idx < t.vals.len
+  result = t.vals[idx]
+
+proc `[]`*[T](t: BiTable[T]; litId: LitId): lent T {.inline.} =
+  let idx = idToIdx litId
+  assert idx < t.vals.len
+  result = t.vals[idx]
+
+proc hash*[T](t: BiTable[T]): Hash =
+  ## as the keys are hashes of the values, we simply use them instead
+  var h: Hash = 0
+  for i, n in pairs t.keys:
+    h = h !& hash((i, n))
+  result = !$h
+
+proc store*[T](f: var RodFile; t: BiTable[T]) =
+  storeSeq(f, t.vals)
+  storeSeq(f, t.keys)
+
+proc load*[T](f: var RodFile; t: var BiTable[T]) =
+  loadSeq(f, t.vals)
+  loadSeq(f, t.keys)
+
+proc sizeOnDisc*(t: BiTable[string]): int =
+  result = 4
+  for x in t.vals:
+    result += x.len + 4
+  result += t.keys.len * sizeof(LitId)
+
+when isMainModule:
+
+  var t: BiTable[string]
+
+  echo getOrIncl(t, "hello")
+
+  echo getOrIncl(t, "hello")
+  echo getOrIncl(t, "hello3")
+  echo getOrIncl(t, "hello4")
+  echo getOrIncl(t, "helloasfasdfdsa")
+  echo getOrIncl(t, "hello")
+  echo getKeyId(t, "hello")
+  echo getKeyId(t, "none")
+
+  for i in 0 ..< 100_000:
+    discard t.getOrIncl($i & "___" & $i)
+
+  for i in 0 ..< 100_000:
+    assert t.getOrIncl($i & "___" & $i).idToIdx == i + 4
+  echo "begin"
+  echo t.vals.len
+
+  echo t.vals[0]
+  echo t.vals[1004]
+
+  echo "middle"
+
+  var tf: BiTable[float]
+
+  discard tf.getOrIncl(0.4)
+  discard tf.getOrIncl(16.4)
+  discard tf.getOrIncl(32.4)
+  echo getKeyId(tf, 32.4)
+
+  var f2 = open("testblah.bin", fmWrite)
+  echo store(f2, tf)
+  f2.close
+
+  var f1 = open("testblah.bin", fmRead)
+
+  var t2: BiTable[float]
+
+  echo f1.load(t2)
+  echo t2.vals.len
+
+  echo getKeyId(t2, 32.4)
+
+  echo "end"
+
+
+  f1.close
--- a/compiler/ic/cbackend.nim
+++ b/compiler/ic/cbackend.nim
@@ -0,0 +1,180 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2021 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## New entry point into our C/C++ code generator. Ideally
+## somebody would rewrite the old backend (which is 8000 lines of crufty Nim code)
+## to work on packed trees directly and produce the C code as an AST which can
+## then be rendered to text in a very simple manner. Unfortunately nobody wrote
+## this code. So instead we wrap the existing cgen.nim and its friends so that
+## we call directly into the existing code generation logic but avoiding the
+## naive, outdated `passes` design. Thus you will see some
+## `useAliveDataFromDce in flags` checks in the old code -- the old code is
+## also doing cross-module dependency tracking and DCE that we don't need
+## anymore. DCE is now done as prepass over the entire packed module graph.
+
+import std/[packedsets, algorithm, tables]
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+import ".."/[ast, options, lineinfos, modulegraphs, cgendata, cgen,
+  pathutils, extccomp, msgs, modulepaths]
+
+import packed_ast, ic, dce, rodfiles
+
+proc unpackTree(g: ModuleGraph; thisModule: int;
+                tree: PackedTree; n: NodePos): PNode =
+  var decoder = initPackedDecoder(g.config, g.cache)
+  result = loadNodes(decoder, g.packed, thisModule, tree, n)
+
+proc setupBackendModule(g: ModuleGraph; m: var LoadedModule) =
+  if g.backend == nil:
+    g.backend = cgendata.newModuleList(g)
+  assert g.backend != nil
+  var bmod = cgen.newModule(BModuleList(g.backend), m.module, g.config)
+  bmod.idgen = idgenFromLoadedModule(m)
+
+proc generateCodeForModule(g: ModuleGraph; m: var LoadedModule; alive: var AliveSyms) =
+  var bmod = BModuleList(g.backend).modules[m.module.position]
+  assert bmod != nil
+  bmod.flags.incl useAliveDataFromDce
+  bmod.alive = move alive[m.module.position]
+
+  for p in allNodes(m.fromDisk.topLevel):
+    let n = unpackTree(g, m.module.position, m.fromDisk.topLevel, p)
+    cgen.genTopLevelStmt(bmod, n)
+
+  finalCodegenActions(g, bmod, newNodeI(nkStmtList, m.module.info))
+  for disp in getDispatchers(g):
+    genProcAux(bmod, disp)
+  m.fromDisk.backendFlags = cgen.whichInitProcs(bmod)
+
+proc replayTypeInfo(g: ModuleGraph; m: var LoadedModule; origin: FileIndex) =
+  for x in mitems(m.fromDisk.emittedTypeInfo):
+    #echo "found type ", x, " for file ", int(origin)
+    g.emittedTypeInfo[x] = origin
+
+proc addFileToLink(config: ConfigRef; m: PSym) =
+  let filename = AbsoluteFile toFullPath(config, m.position.FileIndex)
+  let ext =
+      if config.backend == backendCpp: ".nim.cpp"
+      elif config.backend == backendObjc: ".nim.m"
+      else: ".nim.c"
+  let cfile = changeFileExt(completeCfilePath(config,
+                            mangleModuleName(config, filename).AbsoluteFile), ext)
+  let objFile = completeCfilePath(config, toObjFile(config, cfile))
+  if fileExists(objFile):
+    var cf = Cfile(nimname: m.name.s, cname: cfile,
+                   obj: objFile,
+                   flags: {CfileFlag.Cached})
+    addFileToCompile(config, cf)
+
+when defined(debugDce):
+  import os, std/packedsets
+
+proc storeAliveSymsImpl(asymFile: AbsoluteFile; s: seq[int32]) =
+  var f = rodfiles.create(asymFile.string)
+  f.storeHeader()
+  f.storeSection aliveSymsSection
+  f.storeSeq(s)
+  close f
+
+template prepare {.dirty.} =
+  let asymFile = toRodFile(config, AbsoluteFile toFullPath(config, position.FileIndex), ".alivesyms")
+  var s = newSeqOfCap[int32](alive[position].len)
+  for a in items(alive[position]): s.add int32(a)
+  sort(s)
+
+proc storeAliveSyms(config: ConfigRef; position: int; alive: AliveSyms) =
+  prepare()
+  storeAliveSymsImpl(asymFile, s)
+
+proc aliveSymsChanged(config: ConfigRef; position: int; alive: AliveSyms): bool =
+  prepare()
+  var f2 = rodfiles.open(asymFile.string)
+  f2.loadHeader()
+  f2.loadSection aliveSymsSection
+  var oldData: seq[int32] = @[]
+  f2.loadSeq(oldData)
+  f2.close
+  if f2.err == ok and oldData == s:
+    result = false
+  else:
+    when defined(debugDce):
+      let oldAsSet = toPackedSet[int32](oldData)
+      let newAsSet = toPackedSet[int32](s)
+      echo "set of live symbols changed ", asymFile.changeFileExt("rod"), " ", position, " ", f2.err
+      echo "in old but not in new ", oldAsSet.difference(newAsSet), " number of entries in old ", oldAsSet.len
+      echo "in new but not in old ", newAsSet.difference(oldAsSet), " number of entries in new ", newAsSet.len
+      #if execShellCmd(getAppFilename() & " rod " & quoteShell(asymFile.changeFileExt("rod"))) != 0:
+      #  echo "command failed"
+    result = true
+    storeAliveSymsImpl(asymFile, s)
+
+proc genPackedModule(g: ModuleGraph, i: int; alive: var AliveSyms) =
+  # case statement here to enforce exhaustive checks.
+  case g.packed[i].status
+  of undefined:
+    discard "nothing to do"
+  of loading, stored:
+    assert false
+  of storing, outdated:
+    storeAliveSyms(g.config, g.packed[i].module.position, alive)
+    generateCodeForModule(g, g.packed[i], alive)
+    closeRodFile(g, g.packed[i].module)
+  of loaded:
+    if g.packed[i].loadedButAliveSetChanged:
+      generateCodeForModule(g, g.packed[i], alive)
+    else:
+      addFileToLink(g.config, g.packed[i].module)
+      replayTypeInfo(g, g.packed[i], FileIndex(i))
+
+      if g.backend == nil:
+        g.backend = cgendata.newModuleList(g)
+      registerInitProcs(BModuleList(g.backend), g.packed[i].module, g.packed[i].fromDisk.backendFlags)
+
+proc generateCode*(g: ModuleGraph) =
+  ## The single entry point, generate C(++) code for the entire
+  ## Nim program aka `ModuleGraph`.
+  resetForBackend(g)
+  var alive = computeAliveSyms(g.packed, g.config)
+
+  when false:
+    for i in 0..<len(g.packed):
+      echo i, " is of status ", g.packed[i].status, " ", toFullPath(g.config, FileIndex(i))
+
+  # First pass: Setup all the backend modules for all the modules that have
+  # changed:
+  for i in 0..<len(g.packed):
+    # case statement here to enforce exhaustive checks.
+    case g.packed[i].status
+    of undefined:
+      discard "nothing to do"
+    of loading, stored:
+      assert false
+    of storing, outdated:
+      setupBackendModule(g, g.packed[i])
+    of loaded:
+      # Even though this module didn't change, DCE might trigger a change.
+      # Consider this case: Module A uses symbol S from B and B does not use
+      # S itself. A is then edited not to use S either. Thus we have to
+      # recompile B in order to remove S from the final result.
+      if aliveSymsChanged(g.config, g.packed[i].module.position, alive):
+        g.packed[i].loadedButAliveSetChanged = true
+        setupBackendModule(g, g.packed[i])
+
+  # Second pass: Code generation.
+  let mainModuleIdx = g.config.projectMainIdx2.int
+  # We need to generate the main module last, because only then
+  # all init procs have been registered:
+  for i in 0..<len(g.packed):
+    if i != mainModuleIdx:
+      genPackedModule(g, i, alive)
+  if mainModuleIdx >= 0:
+    genPackedModule(g, mainModuleIdx, alive)
--- a/compiler/ic/dce.nim
+++ b/compiler/ic/dce.nim
@@ -0,0 +1,169 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2021 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Dead code elimination (=DCE) for IC.
+
+import std/[intsets, tables]
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+import ".." / [ast, options, lineinfos, types]
+
+import packed_ast, ic, bitabs
+
+type
+  AliveSyms* = seq[IntSet]
+  AliveContext* = object ## Purpose is to fill the 'alive' field.
+    stack: seq[(int, TOptions, NodePos)] ## A stack for marking symbols as alive.
+    decoder: PackedDecoder ## We need a PackedDecoder for module ID address translations.
+    thisModule: int  ## The module we're currently analysing for DCE.
+    alive: AliveSyms ## The final result of our computation.
+    options: TOptions
+    compilerProcs: Table[string, (int, int32)]
+
+proc isExportedToC(c: var AliveContext; g: PackedModuleGraph; symId: int32): bool =
+  ## "Exported to C" procs are special (these are marked with '.exportc') because these
+  ## must not be optimized away!
+  let symPtr = unsafeAddr g[c.thisModule].fromDisk.syms[symId]
+  let flags = symPtr.flags
+  # due to a bug/limitation in the lambda lifting, unused inner procs
+  # are not transformed correctly; issue (#411). However, the whole purpose here
+  # is to eliminate unused procs. So there is no special logic required for this case.
+  if sfCompileTime notin flags:
+    if ({sfExportc, sfCompilerProc} * flags != {}) or
+        (symPtr.kind == skMethod):
+      result = true
+    else:
+      result = false
+      # XXX: This used to be a condition to:
+      #  (sfExportc in prc.flags and lfExportLib in prc.loc.flags) or
+    if sfCompilerProc in flags:
+      c.compilerProcs[g[c.thisModule].fromDisk.strings[symPtr.name]] = (c.thisModule, symId)
+  else:
+    result = false
+
+template isNotGeneric(n: NodePos): bool = ithSon(tree, n, genericParamsPos).kind == nkEmpty
+
+proc followLater(c: var AliveContext; g: PackedModuleGraph; module: int; item: int32) =
+  ## Marks a symbol 'item' as used and later in 'followNow' the symbol's body will
+  ## be analysed.
+  if not c.alive[module].containsOrIncl(item):
+    var body = g[module].fromDisk.syms[item].ast
+    if body != emptyNodeId:
+      let opt = g[module].fromDisk.syms[item].options
+      if g[module].fromDisk.syms[item].kind in routineKinds:
+        body = NodeId ithSon(g[module].fromDisk.bodies, NodePos body, bodyPos)
+      c.stack.add((module, opt, NodePos(body)))
+
+    when false:
+      let nid = g[module].fromDisk.syms[item].name
+      if nid != LitId(0):
+        let name = g[module].fromDisk.strings[nid]
+        if name in ["nimFrame", "callDepthLimitReached"]:
+          echo "I was called! ", name, " body exists: ", body != emptyNodeId, " ", module, " ", item
+
+proc requestCompilerProc(c: var AliveContext; g: PackedModuleGraph; name: string) =
+  let (module, item) = c.compilerProcs[name]
+  followLater(c, g, module, item)
+
+proc loadTypeKind(t: PackedItemId; c: AliveContext; g: PackedModuleGraph; toSkip: set[TTypeKind]): TTypeKind =
+  template kind(t: ItemId): TTypeKind = g[t.module].fromDisk.types[t.item].kind
+
+  var t2 = translateId(t, g, c.thisModule, c.decoder.config)
+  result = t2.kind
+  while result in toSkip:
+    t2 = translateId(g[t2.module].fromDisk.types[t2.item].types[^1], g, t2.module, c.decoder.config)
+    result = t2.kind
+
+proc rangeCheckAnalysis(c: var AliveContext; g: PackedModuleGraph; tree: PackedTree; n: NodePos) =
+  ## Replicates the logic of `ccgexprs.genRangeChck`.
+  ## XXX Refactor so that the duplicated logic is avoided. However, for now it's not clear
+  ## the approach has enough merit.
+  var dest = loadTypeKind(n.typ, c, g, abstractVar)
+  if optRangeCheck notin c.options or dest in {tyUInt..tyUInt64}:
+    discard "no need to generate a check because it was disabled"
+  else:
+    let n0t = loadTypeKind(n.firstSon.typ, c, g, {})
+    if n0t in {tyUInt, tyUInt64}:
+      c.requestCompilerProc(g, "raiseRangeErrorNoArgs")
+    else:
+      let raiser =
+        case loadTypeKind(n.typ, c, g, abstractVarRange)
+        of tyUInt..tyUInt64, tyChar: "raiseRangeErrorU"
+        of tyFloat..tyFloat128: "raiseRangeErrorF"
+        else: "raiseRangeErrorI"
+      c.requestCompilerProc(g, raiser)
+
+proc aliveCode(c: var AliveContext; g: PackedModuleGraph; tree: PackedTree; n: NodePos) =
+  ## Marks the symbols we encounter when we traverse the AST at `tree[n]` as alive, unless
+  ## it is purely in a declarative context (type section etc.).
+  case n.kind
+  of nkNone..pred(nkSym), succ(nkSym)..nkNilLit:
+    discard "ignore non-sym atoms"
+  of nkSym:
+    # This symbol is alive and everything its body references.
+    followLater(c, g, c.thisModule, tree[n].soperand)
+  of nkModuleRef:
+    let (n1, n2) = sons2(tree, n)
+    assert n1.kind == nkNone
+    assert n2.kind == nkNone
+    let m = n1.litId
+    let item = tree[n2].soperand
+    let otherModule = toFileIndexCached(c.decoder, g, c.thisModule, m).int
+    followLater(c, g, otherModule, item)
+  of nkMacroDef, nkTemplateDef, nkTypeSection, nkTypeOfExpr,
+     nkCommentStmt, nkIncludeStmt,
+     nkImportStmt, nkImportExceptStmt, nkExportStmt, nkExportExceptStmt,
+     nkFromStmt, nkStaticStmt:
+    discard
+  of nkVarSection, nkLetSection, nkConstSection:
+    # XXX ignore the defining local variable name?
+    for son in sonsReadonly(tree, n):
+      aliveCode(c, g, tree, son)
+  of nkChckRangeF, nkChckRange64, nkChckRange:
+    rangeCheckAnalysis(c, g, tree, n)
+  of nkProcDef, nkConverterDef, nkMethodDef, nkFuncDef, nkIteratorDef:
+    if n.firstSon.kind == nkSym and isNotGeneric(n):
+      let item = tree[n.firstSon].soperand
+      if isExportedToC(c, g, item):
+        # This symbol is alive and everything its body references.
+        followLater(c, g, c.thisModule, item)
+  else:
+    for son in sonsReadonly(tree, n):
+      aliveCode(c, g, tree, son)
+
+proc followNow(c: var AliveContext; g: PackedModuleGraph) =
+  ## Mark all entries in the stack. Marking can add more entries
+  ## to the stack but eventually we have looked at every alive symbol.
+  while c.stack.len > 0:
+    let (modId, opt, ast) = c.stack.pop()
+    c.thisModule = modId
+    c.options = opt
+    aliveCode(c, g, g[modId].fromDisk.bodies, ast)
+
+proc computeAliveSyms*(g: PackedModuleGraph; conf: ConfigRef): AliveSyms =
+  ## Entry point for our DCE algorithm.
+  var c = AliveContext(stack: @[], decoder: PackedDecoder(config: conf),
+                       thisModule: -1, alive: newSeq[IntSet](g.len),
+                       options: conf.options)
+  for i in countdown(len(g)-1, 0):
+    if g[i].status != undefined:
+      c.thisModule = i
+      for p in allNodes(g[i].fromDisk.topLevel):
+        aliveCode(c, g, g[i].fromDisk.topLevel, p)
+
+  followNow(c, g)
+  result = move(c.alive)
+
+proc isAlive*(a: AliveSyms; module: int, item: int32): bool =
+  ## Backends use this to query if a symbol is `alive` which means
+  ## we need to produce (C/C++/etc) code for it.
+  result = a[module].contains(item)
+
--- a/compiler/ic/design.rst
+++ b/compiler/ic/design.rst
@@ -0,0 +1,56 @@
+====================================
+  Incremental Recompilations
+====================================
+
+We split the Nim compiler into a frontend and a backend.
+The frontend produces a set of `.rod` files. Every `.nim` module
+produces its own `.rod` file.
+
+- The IR must be a faithful representation of the AST in memory.
+- The backend can do its own caching but doesn't have to. In the
+  current implementation the backend also caches its results.
+
+Advantage of the "set of files" vs the previous global database:
+- By construction, we either read from the `.rod` file or from the
+  `.nim` file, there can be no inconsistency. There can also be no
+  partial updates.
+- No dependency to external packages (SQLite). SQLite simply is too
+  slow and the old way of serialization was too slow too. We use a
+  format designed for Nim and expect to base further tools on this
+  file format.
+
+References to external modules must be (moduleId, symId) pairs.
+The symbol IDs are module specific. This way no global ID increment
+mechanism needs to be implemented that we could get wrong. ModuleIds
+are rod-file specific too.
+
+
+
+Global state
+------------
+
+There is no global state.
+
+Rod File Format
+---------------
+
+It's a simple binary file format. `rodfiles.nim` contains some details.
+
+
+Backend
+-------
+
+Nim programmers have to come to enjoy whole-program dead code elimination,
+by default. Since this is a "whole program" optimization, it does break
+modularity. However, thanks to the packed AST representation we can perform
+this global analysis without having to unpack anything. This is basically
+a mark&sweep GC algorithm:
+
+- Start with the top level statements. Every symbol that is referenced
+  from a top level statement is not "dead" and needs to be compiled by
+  the backend.
+- Every symbol referenced from a referenced symbol also has to be
+  compiled.
+
+Caching logic: Only if the set of alive symbols is different from the
+last run, the module has to be regenerated.
--- a/compiler/ic/enum2nif.nim
+++ b/compiler/ic/enum2nif.nim
--- a/compiler/ic/ic.nim
+++ b/compiler/ic/ic.nim
--- a/compiler/ic/iclineinfos.nim
+++ b/compiler/ic/iclineinfos.nim
@@ -0,0 +1,84 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2024 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# For the line information we use 32 bits. They are used as follows:
+# Bit 0 (AsideBit): If we have inline line information or not. If not, the
+# remaining 31 bits are used as an index into a seq[(LitId, int, int)].
+#
+# We use 10 bits for the "file ID", this means a program can consist of as much
+# as 1024 different files. (If it uses more files than that, the overflow bit
+# would be set.)
+# This means we have 21 bits left to encode the (line, col) pair. We use 7 bits for the column
+# so 128 is the limit and 14 bits for the line number.
+# The packed representation supports files with up to 16384 lines.
+# Keep in mind that whenever any limit is reached the AsideBit is set and the real line
+# information is kept in a side channel.
+
+import std / assertions
+
+const
+  AsideBit = 1
+  FileBits = 10
+  LineBits = 14
+  ColBits = 7
+  FileMax = (1 shl FileBits) - 1
+  LineMax = (1 shl LineBits) - 1
+  ColMax = (1 shl ColBits) - 1
+
+static:
+  assert AsideBit + FileBits + LineBits + ColBits == 32
+
+import .. / ic / [bitabs, rodfiles] # for LitId
+
+type
+  PackedLineInfo* = distinct uint32
+
+  LineInfoManager* = object
+    aside: seq[(LitId, int32, int32)]
+
+const
+  NoLineInfo* = PackedLineInfo(0'u32)
+
+proc pack*(m: var LineInfoManager; file: LitId; line, col: int32): PackedLineInfo =
+  if file.uint32 <= FileMax.uint32 and line <= LineMax and col <= ColMax:
+    let col = if col < 0'i32: 0'u32 else: col.uint32
+    let line = if line < 0'i32: 0'u32 else: line.uint32
+    # use inline representation:
+    result = PackedLineInfo((file.uint32 shl 1'u32) or (line shl uint32(AsideBit + FileBits)) or
+      (col shl uint32(AsideBit + FileBits + LineBits)))
+  else:
+    result = PackedLineInfo((m.aside.len shl 1) or AsideBit)
+    m.aside.add (file, line, col)
+
+proc unpack*(m: LineInfoManager; i: PackedLineInfo): (LitId, int32, int32) =
+  let i = i.uint32
+  if (i and 1'u32) == 0'u32:
+    # inline representation:
+    result = (LitId((i shr 1'u32) and FileMax.uint32),
+      int32((i shr uint32(AsideBit + FileBits)) and LineMax.uint32),
+      int32((i shr uint32(AsideBit + FileBits + LineBits)) and ColMax.uint32))
+  else:
+    result = m.aside[int(i shr 1'u32)]
+
+proc getFileId*(m: LineInfoManager; i: PackedLineInfo): LitId =
+  result = unpack(m, i)[0]
+
+proc store*(r: var RodFile; m: LineInfoManager) = storeSeq(r, m.aside)
+proc load*(r: var RodFile; m: var LineInfoManager) = loadSeq(r, m.aside)
+
+when isMainModule:
+  var m = LineInfoManager(aside: @[])
+  for i in 0'i32..<16388'i32:
+    for col in 0'i32..<100'i32:
+      let packed = pack(m, LitId(1023), i, col)
+      let u = unpack(m, packed)
+      assert u[0] == LitId(1023)
+      assert u[1] == i
+      assert u[2] == col
+  echo m.aside.len
--- a/compiler/ic/integrity.nim
+++ b/compiler/ic/integrity.nim
@@ -0,0 +1,155 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2021 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Integrity checking for a set of .rod files.
+## The set must cover a complete Nim project.
+
+import std/[sets, tables]
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+import ".." / [ast, modulegraphs]
+import packed_ast, bitabs, ic
+
+type
+  CheckedContext = object
+    g: ModuleGraph
+    thisModule: int32
+    checkedSyms: HashSet[ItemId]
+    checkedTypes: HashSet[ItemId]
+
+proc checkType(c: var CheckedContext; typeId: PackedItemId)
+proc checkForeignSym(c: var CheckedContext; symId: PackedItemId)
+proc checkNode(c: var CheckedContext; tree: PackedTree; n: NodePos)
+
+proc checkTypeObj(c: var CheckedContext; typ: PackedType) =
+  for child in typ.types:
+    checkType(c, child)
+  if typ.n != emptyNodeId:
+    checkNode(c, c.g.packed[c.thisModule].fromDisk.bodies, NodePos typ.n)
+  if typ.sym != nilItemId:
+    checkForeignSym(c, typ.sym)
+  if typ.owner != nilItemId:
+    checkForeignSym(c, typ.owner)
+  checkType(c, typ.typeInst)
+
+proc checkType(c: var CheckedContext; typeId: PackedItemId) =
+  if typeId == nilItemId: return
+  let itemId = translateId(typeId, c.g.packed, c.thisModule, c.g.config)
+  if not c.checkedTypes.containsOrIncl(itemId):
+    let oldThisModule = c.thisModule
+    c.thisModule = itemId.module
+    checkTypeObj c, c.g.packed[itemId.module].fromDisk.types[itemId.item]
+    c.thisModule = oldThisModule
+
+proc checkSym(c: var CheckedContext; s: PackedSym) =
+  if s.name != LitId(0):
+    assert c.g.packed[c.thisModule].fromDisk.strings.hasLitId s.name
+  checkType c, s.typ
+  if s.ast != emptyNodeId:
+    checkNode(c, c.g.packed[c.thisModule].fromDisk.bodies, NodePos s.ast)
+  if s.owner != nilItemId:
+    checkForeignSym(c, s.owner)
+
+proc checkLocalSym(c: var CheckedContext; item: int32) =
+  let itemId = ItemId(module: c.thisModule, item: item)
+  if not c.checkedSyms.containsOrIncl(itemId):
+    checkSym c, c.g.packed[c.thisModule].fromDisk.syms[item]
+
+proc checkForeignSym(c: var CheckedContext; symId: PackedItemId) =
+  let itemId = translateId(symId, c.g.packed, c.thisModule, c.g.config)
+  if not c.checkedSyms.containsOrIncl(itemId):
+    let oldThisModule = c.thisModule
+    c.thisModule = itemId.module
+    checkSym c, c.g.packed[itemId.module].fromDisk.syms[itemId.item]
+    c.thisModule = oldThisModule
+
+proc checkNode(c: var CheckedContext; tree: PackedTree; n: NodePos) =
+  let t = findType(tree, n)
+  if t != nilItemId:
+    checkType(c, t)
+  case n.kind
+  of nkEmpty, nkNilLit, nkType, nkNilRodNode:
+    discard
+  of nkIdent:
+    assert c.g.packed[c.thisModule].fromDisk.strings.hasLitId n.litId
+  of nkSym:
+    checkLocalSym(c, tree[n].soperand)
+  of directIntLit:
+    discard
+  of externIntLit, nkFloatLit..nkFloat128Lit:
+    assert c.g.packed[c.thisModule].fromDisk.numbers.hasLitId n.litId
+  of nkStrLit..nkTripleStrLit:
+    assert c.g.packed[c.thisModule].fromDisk.strings.hasLitId n.litId
+  of nkModuleRef:
+    let (n1, n2) = sons2(tree, n)
+    assert n1.kind == nkNone
+    assert n2.kind == nkNone
+    checkForeignSym(c, PackedItemId(module: n1.litId, item: tree[n2].soperand))
+  else:
+    for n0 in sonsReadonly(tree, n):
+      checkNode(c, tree, n0)
+
+proc checkTree(c: var CheckedContext; t: PackedTree) =
+  for p in allNodes(t): checkNode(c, t, p)
+
+proc checkLocalSymIds(c: var CheckedContext; m: PackedModule; symIds: seq[int32]) =
+  for symId in symIds:
+    assert symId >= 0 and symId < m.syms.len, $symId & " " & $m.syms.len
+
+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
+
+  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[0] == m.syms[e[1]].name
+
+  for e in m.compilerProcs:
+    #assert e[1] >= 0 and e[1] < m.syms.len
+    assert e[0] == m.syms[e[1]].name
+
+  checkLocalSymIds c, m, m.converters
+  checkLocalSymIds c, m, m.methods
+  checkLocalSymIds c, m, m.trmacros
+  checkLocalSymIds c, m, m.pureEnums
+  #[
+    To do: Check all these fields:
+
+    reexports*: seq[(LitId, PackedItemId)]
+    macroUsages*: seq[(PackedItemId, PackedLineInfo)]
+
+    typeInstCache*: seq[(PackedItemId, PackedItemId)]
+    procInstCache*: seq[PackedInstantiation]
+    attachedOps*: seq[(TTypeAttachedOp, PackedItemId, PackedItemId)]
+    methodsPerGenericType*: seq[(PackedItemId, int, PackedItemId)]
+    enumToStringProcs*: seq[(PackedItemId, PackedItemId)]
+    methodsPerType*: seq[(PackedItemId, PackedItemId)]
+    dispatchers*: seq[PackedItemId]
+  ]#
+
+proc checkIntegrity*(g: ModuleGraph) =
+  var c = CheckedContext(g: g)
+  for i in 0..<len(g.packed):
+    # case statement here to enforce exhaustive checks.
+    case g.packed[i].status
+    of undefined:
+      discard "nothing to do"
+    of loading:
+      assert false, "cannot check integrity: Module still loading"
+    of stored, storing, outdated, loaded:
+      c.thisModule = int32 i
+      checkModule(c, g.packed[i].fromDisk)
--- a/compiler/ic/navigator.nim
+++ b/compiler/ic/navigator.nim
@@ -0,0 +1,183 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2021 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Supports the "nim check --ic:on --defusages:FILE,LINE,COL"
+## 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]
+
+from std/os import nil
+from std/private/miscdollars import toLocation
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+import ".." / [ast, modulegraphs, msgs, options]
+import iclineinfos
+import packed_ast, bitabs, ic
+
+type
+  UnpackedLineInfo = object
+    file: LitId
+    line, col: int
+  NavContext = object
+    g: ModuleGraph
+    thisModule: int32
+    trackPos: UnpackedLineInfo
+    alreadyEmitted: HashSet[string]
+    outputSep: char # for easier testing, use short filenames and spaces instead of tabs.
+
+proc isTracked(man: LineInfoManager; current: PackedLineInfo, trackPos: UnpackedLineInfo, tokenLen: int): bool =
+  let (currentFile, currentLine, currentCol) = man.unpack(current)
+  if currentFile == trackPos.file and currentLine == trackPos.line:
+    let col = trackPos.col
+    if col >= currentCol and col < currentCol+tokenLen:
+      result = true
+    else:
+      result = false
+  else:
+    result = false
+
+proc searchLocalSym(c: var NavContext; s: PackedSym; info: PackedLineInfo): bool =
+  result = s.name != LitId(0) and
+    isTracked(c.g.packed[c.thisModule].fromDisk.man, info, c.trackPos, c.g.packed[c.thisModule].fromDisk.strings[s.name].len)
+
+proc searchForeignSym(c: var NavContext; s: ItemId; info: PackedLineInfo): bool =
+  let name = c.g.packed[s.module].fromDisk.syms[s.item].name
+  result = name != LitId(0) and
+    isTracked(c.g.packed[c.thisModule].fromDisk.man, info, c.trackPos, c.g.packed[s.module].fromDisk.strings[name].len)
+
+const
+  EmptyItemId = ItemId(module: -1'i32, item: -1'i32)
+
+proc search(c: var NavContext; tree: PackedTree): ItemId =
+  # We use the linear representation here directly:
+  for i in 0..<len(tree):
+    let i = NodePos(i)
+    case tree[i].kind
+    of nkSym:
+      let item = tree[i].soperand
+      if searchLocalSym(c, c.g.packed[c.thisModule].fromDisk.syms[item], tree[i].info):
+        return ItemId(module: c.thisModule, item: item)
+    of nkModuleRef:
+      let (currentFile, currentLine, currentCol) = c.g.packed[c.thisModule].fromDisk.man.unpack(tree[i].info)
+      if currentLine == c.trackPos.line and currentFile == c.trackPos.file:
+        let (n1, n2) = sons2(tree, i)
+        assert n1.kind == nkInt32Lit
+        assert n2.kind == nkInt32Lit
+        let pId = PackedItemId(module: n1.litId, item: tree[n2].soperand)
+        let itemId = translateId(pId, c.g.packed, c.thisModule, c.g.config)
+        if searchForeignSym(c, itemId, tree[i].info):
+          return itemId
+    else: discard
+  return EmptyItemId
+
+proc isDecl(tree: PackedTree; n: NodePos): bool =
+  # XXX This is not correct yet.
+  const declarativeNodes = procDefs + {nkMacroDef, nkTemplateDef,
+    nkLetSection, nkVarSection, nkUsingStmt, nkConstSection, nkTypeSection,
+    nkIdentDefs, nkEnumTy, nkVarTuple}
+  result = n.int >= 0 and tree[n].kind in declarativeNodes
+
+proc usage(c: var NavContext; info: PackedLineInfo; isDecl: bool) =
+  let (fileId, line, col) = unpack(c.g.packed[c.thisModule].fromDisk.man, info)
+  var m = ""
+  var file = c.g.packed[c.thisModule].fromDisk.strings[fileId]
+  if c.outputSep == ' ':
+    file = os.extractFilename file
+  toLocation(m, file, line, col + ColOffset)
+  if not c.alreadyEmitted.containsOrIncl(m):
+    msgWriteln c.g.config, (if isDecl: "def" else: "usage") & c.outputSep & m
+
+proc list(c: var NavContext; tree: PackedTree; sym: ItemId) =
+  for i in 0..<len(tree):
+    let i = NodePos(i)
+    case tree[i].kind
+    of nkSym:
+      let item = tree[i].soperand
+      if sym.item == item and sym.module == c.thisModule:
+        usage(c, tree[i].info, isDecl(tree, parent(i)))
+    of nkModuleRef:
+      let (n1, n2) = sons2(tree, i)
+      assert n1.kind == nkNone
+      assert n2.kind == nkNone
+      let pId = PackedItemId(module: n1.litId, item: tree[n2].soperand)
+      let itemId = translateId(pId, c.g.packed, c.thisModule, c.g.config)
+      if itemId.item == sym.item and sym.module == itemId.module:
+        usage(c, tree[i].info, isDecl(tree, parent(i)))
+    else: discard
+
+proc searchForIncludeFile(g: ModuleGraph; fullPath: string): int =
+  for i in 0..<len(g.packed):
+    for k in 1..high(g.packed[i].fromDisk.includes):
+      # we start from 1 because the first "include" file is
+      # the module's filename.
+      if os.cmpPaths(g.packed[i].fromDisk.strings[g.packed[i].fromDisk.includes[k][0]], fullPath) == 0:
+        return i
+  return -1
+
+proc nav(g: ModuleGraph) =
+  # translate the track position to a packed position:
+  let unpacked = g.config.m.trackPos
+  var mid = unpacked.fileIndex.int
+
+  let fullPath = toFullPath(g.config, unpacked.fileIndex)
+
+  if g.packed[mid].status == undefined:
+    # check if 'mid' is an include file of some other module:
+    mid = searchForIncludeFile(g, fullPath)
+
+  if mid < 0:
+    localError(g.config, unpacked, "unknown file name: " & fullPath)
+    return
+
+  let fileId = g.packed[mid].fromDisk.strings.getKeyId(fullPath)
+
+  if fileId == LitId(0):
+    internalError(g.config, unpacked, "cannot find a valid file ID")
+    return
+
+  var c = NavContext(
+    g: g,
+    thisModule: int32 mid,
+    trackPos: UnpackedLineInfo(line: unpacked.line.int, col: unpacked.col.int, file: fileId),
+    outputSep: if isDefined(g.config, "nimIcNavigatorTests"): ' ' else: '\t'
+  )
+  var symId = search(c, g.packed[mid].fromDisk.topLevel)
+  if symId == EmptyItemId:
+    symId = search(c, g.packed[mid].fromDisk.bodies)
+
+  if symId == EmptyItemId:
+    localError(g.config, unpacked, "no symbol at this position")
+    return
+
+  for i in 0..<len(g.packed):
+    # case statement here to enforce exhaustive checks.
+    case g.packed[i].status
+    of undefined:
+      discard "nothing to do"
+    of loading:
+      assert false, "cannot check integrity: Module still loading"
+    of stored, storing, outdated, loaded:
+      c.thisModule = int32 i
+      list(c, g.packed[i].fromDisk.topLevel, symId)
+      list(c, g.packed[i].fromDisk.bodies, symId)
+
+proc navDefinition*(g: ModuleGraph) = nav(g)
+proc navUsages*(g: ModuleGraph) = nav(g)
+proc navDefusages*(g: ModuleGraph) = nav(g)
+
+proc writeRodFiles*(g: ModuleGraph) =
+  for i in 0..<len(g.packed):
+    case g.packed[i].status
+    of undefined, loading, stored, loaded:
+      discard "nothing to do"
+    of storing, outdated:
+      closeRodFile(g, g.packed[i].module)
--- a/compiler/ic/packed_ast.nim
+++ b/compiler/ic/packed_ast.nim
@@ -0,0 +1,367 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2020 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Packed AST representation, mostly based on a seq of nodes.
+## For IC support. Far future: Rewrite the compiler passes to
+## use this representation directly in all the transformations,
+## it is superior.
+
+import std/[hashes, tables, strtabs]
+import bitabs, rodfiles
+import ".." / [ast, options]
+
+import iclineinfos
+
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+type
+  SymId* = distinct int32
+  ModuleId* = distinct int32
+  NodePos* = distinct int
+
+  NodeId* = distinct int32
+
+  PackedItemId* = object
+    module*: LitId       # 0 if it's this module
+    item*: int32         # same as the in-memory representation
+
+const
+  nilItemId* = PackedItemId(module: LitId(0), item: 0.int32)
+
+const
+  emptyNodeId* = NodeId(-1)
+
+type
+  PackedLib* = object
+    kind*: TLibKind
+    generated*: bool
+    isOverridden*: bool
+    name*: LitId
+    path*: NodeId
+
+  PackedSym* = object
+    id*: int32
+    kind*: TSymKind
+    name*: LitId
+    typ*: PackedItemId
+    flags*: TSymFlags
+    magic*: TMagic
+    info*: PackedLineInfo
+    ast*: NodeId
+    owner*: PackedItemId
+    guard*: PackedItemId
+    bitsize*: int
+    alignment*: int # for alignment
+    options*: TOptions
+    position*: int
+    offset*: int32
+    disamb*: int32
+    externalName*: LitId # instead of TLoc
+    locFlags*: TLocFlags
+    annex*: PackedLib
+    when hasFFI:
+      cname*: LitId
+    constraint*: NodeId
+    instantiatedFrom*: PackedItemId
+
+  PackedType* = object
+    id*: int32
+    kind*: TTypeKind
+    callConv*: TCallingConvention
+    #nodekind*: TNodeKind
+    flags*: TTypeFlags
+    types*: seq[PackedItemId]
+    n*: NodeId
+    #nodeflags*: TNodeFlags
+    sym*: PackedItemId
+    owner*: PackedItemId
+    size*: BiggestInt
+    align*: int16
+    paddingAtEnd*: int16
+    # not serialized: loc*: TLoc because it is backend-specific
+    typeInst*: PackedItemId
+    nonUniqueId*: int32
+
+  PackedNode* = object     # 8 bytes
+    x: uint32
+    info*: PackedLineInfo
+
+  PackedTree* = object ## usually represents a full Nim module
+    nodes: seq[PackedNode]
+    withFlags: seq[(int32, TNodeFlags)]
+    withTypes: seq[(int32, PackedItemId)]
+
+  PackedInstantiation* = object
+    key*, sym*: PackedItemId
+    concreteTypes*: seq[PackedItemId]
+
+const
+  NodeKindBits = 8'u32
+  NodeKindMask = (1'u32 shl NodeKindBits) - 1'u32
+
+template kind*(n: PackedNode): TNodeKind = TNodeKind(n.x and NodeKindMask)
+template uoperand*(n: PackedNode): uint32 = (n.x shr NodeKindBits)
+template soperand*(n: PackedNode): int32 = int32(uoperand(n))
+
+template toX(k: TNodeKind; operand: uint32): uint32 =
+  uint32(k) or (operand shl NodeKindBits)
+
+template toX(k: TNodeKind; operand: LitId): uint32 =
+  uint32(k) or (operand.uint32 shl NodeKindBits)
+
+template typeId*(n: PackedNode): PackedItemId = n.typ
+
+proc `==`*(a, b: SymId): bool {.borrow.}
+proc hash*(a: SymId): Hash {.borrow.}
+
+proc `==`*(a, b: NodePos): bool {.borrow.}
+#proc `==`*(a, b: PackedItemId): bool {.borrow.}
+proc `==`*(a, b: NodeId): bool {.borrow.}
+
+proc newTreeFrom*(old: PackedTree): PackedTree =
+  result = PackedTree(nodes: @[])
+  when false: result.sh = old.sh
+
+proc addIdent*(tree: var PackedTree; s: LitId; info: PackedLineInfo) =
+  tree.nodes.add PackedNode(x: toX(nkIdent, uint32(s)), info: info)
+
+proc addSym*(tree: var PackedTree; s: int32; info: PackedLineInfo) =
+  tree.nodes.add PackedNode(x: toX(nkSym, cast[uint32](s)), info: info)
+
+proc addSymDef*(tree: var PackedTree; s: SymId; info: PackedLineInfo) =
+  tree.nodes.add PackedNode(x: toX(nkSym, cast[uint32](s)), info: info)
+
+proc isAtom*(tree: PackedTree; pos: int): bool {.inline.} = tree.nodes[pos].kind <= nkNilLit
+
+type
+  PatchPos = distinct int
+
+proc addNode*(t: var PackedTree; kind: TNodeKind; operand: int32;
+              typeId: PackedItemId = nilItemId; info: PackedLineInfo;
+              flags: TNodeFlags = {}) =
+  t.nodes.add PackedNode(x: toX(kind, cast[uint32](operand)), info: info)
+  if flags != {}:
+    t.withFlags.add (t.nodes.len.int32 - 1, flags)
+  if typeId != nilItemId:
+    t.withTypes.add (t.nodes.len.int32 - 1, typeId)
+
+proc prepare*(tree: var PackedTree; kind: TNodeKind; flags: TNodeFlags; typeId: PackedItemId; info: PackedLineInfo): PatchPos =
+  result = PatchPos tree.nodes.len
+  tree.addNode(kind = kind, flags = flags, operand = 0, info = info, typeId = typeId)
+
+proc prepare*(dest: var PackedTree; source: PackedTree; sourcePos: NodePos): PatchPos =
+  result = PatchPos dest.nodes.len
+  dest.nodes.add source.nodes[sourcePos.int]
+
+proc patch*(tree: var PackedTree; pos: PatchPos) =
+  let pos = pos.int
+  let k = tree.nodes[pos].kind
+  assert k > nkNilLit
+  let distance = int32(tree.nodes.len - pos)
+  assert distance > 0
+  tree.nodes[pos].x = toX(k, cast[uint32](distance))
+
+proc len*(tree: PackedTree): int {.inline.} = tree.nodes.len
+
+proc `[]`*(tree: PackedTree; i: NodePos): lent PackedNode {.inline.} =
+  tree.nodes[i.int]
+
+template rawSpan(n: PackedNode): int = int(uoperand(n))
+
+proc nextChild(tree: PackedTree; pos: var int) {.inline.} =
+  if tree.nodes[pos].kind > nkNilLit:
+    assert tree.nodes[pos].uoperand > 0
+    inc pos, tree.nodes[pos].rawSpan
+  else:
+    inc pos
+
+iterator sonsReadonly*(tree: PackedTree; n: NodePos): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > nkNilLit
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+iterator sons*(dest: var PackedTree; tree: PackedTree; n: NodePos): NodePos =
+  let patchPos = prepare(dest, tree, n)
+  for x in sonsReadonly(tree, n): yield x
+  patch dest, patchPos
+
+iterator isons*(dest: var PackedTree; tree: PackedTree;
+                n: NodePos): (int, NodePos) =
+  var i = 0
+  for ch0 in sons(dest, tree, n):
+    yield (i, ch0)
+    inc i
+
+iterator sonsFrom1*(tree: PackedTree; n: NodePos): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > nkNilLit
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  if pos < last:
+    nextChild tree, pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+iterator sonsWithoutLast2*(tree: PackedTree; n: NodePos): NodePos =
+  var count = 0
+  for child in sonsReadonly(tree, n):
+    inc count
+  var pos = n.int
+  assert tree.nodes[pos].kind > nkNilLit
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  while pos < last and count > 2:
+    yield NodePos pos
+    dec count
+    nextChild tree, pos
+
+proc parentImpl(tree: PackedTree; n: NodePos): NodePos =
+  # finding the parent of a node is rather easy:
+  var pos = n.int - 1
+  while pos >= 0 and (isAtom(tree, pos) or (pos + tree.nodes[pos].rawSpan - 1 < n.int)):
+    dec pos
+  #assert pos >= 0, "node has no parent"
+  result = NodePos(pos)
+
+template parent*(n: NodePos): NodePos = parentImpl(tree, n)
+
+proc hasXsons*(tree: PackedTree; n: NodePos; x: int): bool =
+  var count = 0
+  if tree.nodes[n.int].kind > nkNilLit:
+    for child in sonsReadonly(tree, n): inc count
+  result = count == x
+
+proc hasAtLeastXsons*(tree: PackedTree; n: NodePos; x: int): bool =
+  if tree.nodes[n.int].kind > nkNilLit:
+    var count = 0
+    for child in sonsReadonly(tree, n):
+      inc count
+      if count >= x: return true
+  return false
+
+proc firstSon*(tree: PackedTree; n: NodePos): NodePos {.inline.} =
+  NodePos(n.int+1)
+proc kind*(tree: PackedTree; n: NodePos): TNodeKind {.inline.} =
+  tree.nodes[n.int].kind
+proc litId*(tree: PackedTree; n: NodePos): LitId {.inline.} =
+  LitId tree.nodes[n.int].uoperand
+proc info*(tree: PackedTree; n: NodePos): PackedLineInfo {.inline.} =
+  tree.nodes[n.int].info
+
+proc findType*(tree: PackedTree; n: NodePos): PackedItemId =
+  for x in tree.withTypes:
+    if x[0] == int32(n): return x[1]
+    if x[0] > int32(n): return nilItemId
+  return nilItemId
+
+proc findFlags*(tree: PackedTree; n: NodePos): TNodeFlags =
+  for x in tree.withFlags:
+    if x[0] == int32(n): return x[1]
+    if x[0] > int32(n): return {}
+  return {}
+
+template typ*(n: NodePos): PackedItemId =
+  tree.findType(n)
+template flags*(n: NodePos): TNodeFlags =
+  tree.findFlags(n)
+
+template uoperand*(n: NodePos): uint32 =
+  tree.nodes[n.int].uoperand
+
+proc span*(tree: PackedTree; pos: int): int {.inline.} =
+  if isAtom(tree, pos): 1 else: tree.nodes[pos].rawSpan
+
+proc sons2*(tree: PackedTree; n: NodePos): (NodePos, NodePos) =
+  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: PackedTree; n: NodePos): (NodePos, NodePos, NodePos) =
+  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 ithSon*(tree: PackedTree; n: NodePos; i: int): NodePos =
+  result = default(NodePos)
+  if tree.nodes[n.int].kind > nkNilLit:
+    var count = 0
+    for child in sonsReadonly(tree, n):
+      if count == i: return child
+      inc count
+  assert false, "node has no i-th child"
+
+when false:
+  proc `@`*(tree: PackedTree; lit: LitId): lent string {.inline.} =
+    tree.sh.strings[lit]
+
+template kind*(n: NodePos): TNodeKind = tree.nodes[n.int].kind
+template info*(n: NodePos): PackedLineInfo = tree.nodes[n.int].info
+template litId*(n: NodePos): LitId = LitId tree.nodes[n.int].uoperand
+
+template symId*(n: NodePos): SymId = SymId tree.nodes[n.int].soperand
+
+proc firstSon*(n: NodePos): NodePos {.inline.} = NodePos(n.int+1)
+
+const
+  externIntLit* = {nkCharLit,
+    nkIntLit,
+    nkInt8Lit,
+    nkInt16Lit,
+    nkInt32Lit,
+    nkInt64Lit,
+    nkUIntLit,
+    nkUInt8Lit,
+    nkUInt16Lit,
+    nkUInt32Lit,
+    nkUInt64Lit}
+
+  externSIntLit* = {nkIntLit, nkInt8Lit, nkInt16Lit, nkInt32Lit, nkInt64Lit}
+  externUIntLit* = {nkUIntLit, nkUInt8Lit, nkUInt16Lit, nkUInt32Lit, nkUInt64Lit}
+  directIntLit* = nkNone
+
+template copyInto*(dest, n, body) =
+  let patchPos = prepare(dest, tree, n)
+  body
+  patch dest, patchPos
+
+template copyIntoKind*(dest, kind, info, body) =
+  let patchPos = prepare(dest, kind, info)
+  body
+  patch dest, patchPos
+
+proc getNodeId*(tree: PackedTree): NodeId {.inline.} = NodeId tree.nodes.len
+
+iterator allNodes*(tree: PackedTree): NodePos =
+  var p = 0
+  while p < tree.len:
+    yield NodePos(p)
+    let s = span(tree, p)
+    inc p, s
+
+proc toPackedItemId*(item: int32): PackedItemId {.inline.} =
+  PackedItemId(module: LitId(0), item: item)
+
+proc load*(f: var RodFile; t: var PackedTree) =
+  loadSeq f, t.nodes
+  loadSeq f, t.withFlags
+  loadSeq f, t.withTypes
+
+proc store*(f: var RodFile; t: PackedTree) =
+  storeSeq f, t.nodes
+  storeSeq f, t.withFlags
+  storeSeq f, t.withTypes
--- a/compiler/ic/replayer.nim
+++ b/compiler/ic/replayer.nim
@@ -14,82 +14,15 @@
 import ".." / [ast, modulegraphs, trees, extccomp, btrees,
  msgs, lineinfos, pathutils, options, cgmeth]

-import std/[tables, os, strutils, syncio]
+import std/tables

 when defined(nimPreviewSlimSystem):
  import std/assertions

-const BackendActionsExt* = ".cflags"
-  ## Sidecar written by a module's `cg` stage next to its `.c`, carrying the C
-  ## compile/link directives that module's `{.passL.}`/`{.compile.}`/… pragmas
-  ## recorded. See `writeBackendActions`.
+import packed_ast, ic, bitabs

-proc writeBackendActions*(g: ModuleGraph; module: PSym; list: PNode;
-                          outfile: string) =
-  ## Serialize the backend-relevant replay actions of ONE module to `outfile`,
-  ## one tab-separated action per line.
-  ##
-  ## The `link` stage used to recover these by loading the whole import closure
-  ## as `PrecompiledModule`s and re-running `replayBackendActions` over each —
-  ## a 3.7s whole-program graph load, per link, purely to recover a handful of
-  ## strings and the modules' `.c` paths. The producing `cg` process already has
-  ## them in hand, so it writes them down instead and `link` reads them back
-  ## (`applyBackendActions`). Written unconditionally, even when empty: it is a
-  ## declared nifmake output of the `cg` rule, and a missing output re-fires the
-  ## rule for ever.
-  ##
-  ## `localpassc` needs the module's own source path, which only the writer can
-  ## resolve, so it is baked in here as a third field.
-  var content = ""
-  if list != nil:
-    for n in list:
-      if n.kind == nkReplayAction and n.len >= 2 and
-          n[0].kind == nkStrLit and n[1].kind == nkStrLit:
-        case n[0].strVal
-        of "compile":
-          if n.len == 4 and n[2].kind == nkStrLit and n[3].kind == nkStrLit:
-            content.add "compile\t" & n[1].strVal & "\t" & n[2].strVal & "\t" &
-                        n[3].strVal & "\n"
-        of "link", "passl", "passc", "cppdefine":
-          content.add n[0].strVal & "\t" & n[1].strVal & "\n"
-        of "localpassc":
-          content.add "localpassc\t" & n[1].strVal & "\t" &
-                      toFullPathConsiderDirty(g.config, module.info.fileIndex).string & "\n"
-        else: discard
-  writeFile(outfile, content)
-
-proc applyBackendActions*(g: ModuleGraph; infile: string) =
-  ## Apply one module's recorded C directives (see `writeBackendActions`). The
-  ## `link` stage's replacement for loading that module and replaying its AST.
-  if not fileExists(infile): return
-  for line in lines(infile):
-    if line.len == 0: continue
-    let f = line.split('\t')
-    case f[0]
-    of "compile":
-      if f.len == 4:
-        let cname = AbsoluteFile f[1]
-        var cf = Cfile(nimname: splitFile(cname).name, cname: cname,
-                       obj: AbsoluteFile f[2],
-                       flags: {CfileFlag.External}, customArgs: f[3])
-        extccomp.addExternalFileToCompile(g.config, cf)
-    of "link":
-      if f.len == 2: extccomp.addExternalFileToLink(g.config, AbsoluteFile f[1])
-    of "passl":
-      if f.len == 2: extccomp.addLinkOption(g.config, f[1])
-    of "passc":
-      if f.len == 2: extccomp.addCompileOption(g.config, f[1])
-    of "localpassc":
-      if f.len == 3: extccomp.addLocalCompileOption(g.config, f[1], AbsoluteFile f[2])
-    of "cppdefine":
-      if f.len == 2: options.cppDefine(g.config, f[1])
-    else: discard
-
-proc replayStateChanges*(module: PSym; g: ModuleGraph; list: PNode) =
-  ## `list` is an `nkStmtList` of `nkReplayAction` nodes (macro-cache puts/incs/
-  ## adds/incls and a few pragmas) recorded for `module`. Under the NIF backend a
-  ## loaded module's `ast` is never reconstructed, so the caller passes the replay
-  ## actions it parsed out of the module's NIF directly.
+proc replayStateChanges*(module: PSym; g: ModuleGraph) =
+  let list = module.ast
  assert list != nil
  assert list.kind == nkStmtList
  for n in list:
@@ -133,9 +66,8 @@ proc replayStateChanges*(module: PSym; g: ModuleGraph; list: PNode) =
          g.cacheTables[destKey] = initBTree[string, PNode]()
        if not contains(g.cacheTables[destKey], key):
          g.cacheTables[destKey].add(key, val)
-        # else: the same key was already replayed. Under IC the import closure is
-        # replayed (direct module + transitive deps), so the same registration can
-        # legitimately be reached twice; re-applying it is a no-op, not an error.
+        else:
+          internalError(g.config, n.info, "key already exists: " & key)
      of "incl":
        let destKey = n[1].strVal
        let val = n[2]
@@ -157,36 +89,83 @@ proc replayStateChanges*(module: PSym; g: ModuleGraph; list: PNode) =
      else:
        internalAssert g.config, false

-proc replayBackendActions*(g: ModuleGraph; module: PSym; list: PNode) =
-  ## Applies the backend-relevant replay actions (C compile/link directives)
-  ## found in a NIF-loaded module's top-level statement list. The `nifc`
-  ## backend loads modules without going through sem's `replayStateChanges`,
-  ## so e.g. math's `{.passL: "-lm".}` was lost and the final link failed
-  ## with undefined references. VM cache actions are deliberately NOT
-  ## replayed here — codegen does not run macros.
-  if list == nil: return
-  for n in list:
-    if n.kind == nkReplayAction and n.len >= 2 and
-        n[0].kind == nkStrLit and n[1].kind == nkStrLit:
-      case n[0].strVal
-      of "compile":
-        if n.len == 4 and n[2].kind == nkStrLit:
-          let cname = AbsoluteFile n[1].strVal
-          var cf = Cfile(nimname: splitFile(cname).name, cname: cname,
-                         obj: AbsoluteFile n[2].strVal,
-                         flags: {CfileFlag.External},
-                         customArgs: n[3].strVal)
-          extccomp.addExternalFileToCompile(g.config, cf)
-      of "link":
-        extccomp.addExternalFileToLink(g.config, AbsoluteFile n[1].strVal)
-      of "passl":
-        extccomp.addLinkOption(g.config, n[1].strVal)
-      of "passc":
-        extccomp.addCompileOption(g.config, n[1].strVal)
-      of "localpassc":
-        extccomp.addLocalCompileOption(g.config, n[1].strVal,
-          toFullPathConsiderDirty(g.config, module.info.fileIndex))
-      of "cppdefine":
-        options.cppDefine(g.config, n[1].strVal)
-      else:
-        discard
+proc replayBackendProcs*(g: ModuleGraph; module: int) =
+  for it in mitems(g.packed[module].fromDisk.attachedOps):
+    let key = translateId(it[0], g.packed, module, g.config)
+    let op = it[1]
+    let tmp = translateId(it[2], g.packed, module, g.config)
+    let symId = FullId(module: tmp.module, packed: it[2])
+    g.attachedOps[op][key] = LazySym(id: symId, sym: nil)
+
+  for it in mitems(g.packed[module].fromDisk.enumToStringProcs):
+    let key = translateId(it[0], g.packed, module, g.config)
+    let tmp = translateId(it[1], g.packed, module, g.config)
+    let symId = FullId(module: tmp.module, packed: it[1])
+    g.enumToStringProcs[key] = LazySym(id: symId, sym: nil)
+
+  for it in mitems(g.packed[module].fromDisk.methodsPerType):
+    let key = translateId(it[0], g.packed, module, g.config)
+    let tmp = translateId(it[1], g.packed, module, g.config)
+    let symId = FullId(module: tmp.module, packed: it[1])
+    g.methodsPerType.mgetOrPut(key, @[]).add LazySym(id: symId, sym: nil)
+
+  for it in mitems(g.packed[module].fromDisk.dispatchers):
+    let tmp = translateId(it, g.packed, module, g.config)
+    let symId = FullId(module: tmp.module, packed: it)
+    g.dispatchers.add LazySym(id: symId, sym: nil)
+
+proc replayGenericCacheInformation*(g: ModuleGraph; module: int) =
+  ## We remember the generic instantiations a module performed
+  ## in order to to avoid the code bloat that generic code tends
+  ## to imply. This is cheaper than deduplication of identical
+  ## generic instantiations. However, deduplication is more
+  ## powerful and general and I hope to implement it soon too
+  ## (famous last words).
+  assert g.packed[module].status == loaded
+  for it in g.packed[module].fromDisk.typeInstCache:
+    let key = translateId(it[0], g.packed, module, g.config)
+    g.typeInstCache.mgetOrPut(key, @[]).add LazyType(id: FullId(module: module, packed: it[1]), typ: nil)
+
+  for it in mitems(g.packed[module].fromDisk.procInstCache):
+    let key = translateId(it.key, g.packed, module, g.config)
+    let sym = translateId(it.sym, g.packed, module, g.config)
+    var concreteTypes = newSeq[FullId](it.concreteTypes.len)
+    for i in 0..high(it.concreteTypes):
+      let tmp = translateId(it.concreteTypes[i], g.packed, module, g.config)
+      concreteTypes[i] = FullId(module: tmp.module, packed: it.concreteTypes[i])
+
+    g.procInstCache.mgetOrPut(key, @[]).add LazyInstantiation(
+      module: module, sym: FullId(module: sym.module, packed: it.sym),
+      concreteTypes: concreteTypes, inst: nil)
+
+  for it in mitems(g.packed[module].fromDisk.methodsPerGenericType):
+    let key = translateId(it[0], g.packed, module, g.config)
+    let col = it[1]
+    let tmp = translateId(it[2], g.packed, module, g.config)
+    let symId = FullId(module: tmp.module, packed: it[2])
+    g.methodsPerGenericType.mgetOrPut(key, @[]).add (col, LazySym(id: symId, sym: nil))
+
+  replayBackendProcs(g, module)
+
+  for it in mitems(g.packed[module].fromDisk.methods):
+    let sym = loadSymFromId(g.config, g.cache, g.packed, module,
+                            PackedItemId(module: LitId(0), item: it))
+    methodDef(g, g.idgen, sym)
+
+  when false:
+    # not used anymore:
+    for it in mitems(g.packed[module].fromDisk.compilerProcs):
+      let symId = FullId(module: module, packed: PackedItemId(module: LitId(0), item: it[1]))
+      g.lazyCompilerprocs[g.packed[module].fromDisk.sh.strings[it[0]]] = symId
+
+  for it in mitems(g.packed[module].fromDisk.converters):
+    let symId = FullId(module: module, packed: PackedItemId(module: LitId(0), item: it))
+    g.ifaces[module].converters.add LazySym(id: symId, sym: nil)
+
+  for it in mitems(g.packed[module].fromDisk.trmacros):
+    let symId = FullId(module: module, packed: PackedItemId(module: LitId(0), item: it))
+    g.ifaces[module].patterns.add LazySym(id: symId, sym: nil)
+
+  for it in mitems(g.packed[module].fromDisk.pureEnums):
+    let symId = FullId(module: module, packed: PackedItemId(module: LitId(0), item: it))
+    g.ifaces[module].pureEnums.add LazySym(id: symId, sym: nil)
--- a/compiler/ic/rodfiles.nim
+++ b/compiler/ic/rodfiles.nim
@@ -0,0 +1,283 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2020 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Low level binary format used by the compiler to store and load various AST
+## and related data.
+##
+## NB: this is incredibly low level and if you're interested in how the
+##     compiler works and less a storage format, you're probably looking for
+##     the `ic` or `packed_ast` modules to understand the logical format.
+
+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
+## associated data for common interactions such as IO and error tracking
+## (`RodFileError`). The file format broken up into sections (`RodSection`)
+## and preceded by a header (see: `cookie`). The precise layout, section
+## ordering and data following the section are determined by the user. See
+## `ic.loadRodFile`.
+##
+## A basic but "wrong" example of the lifecycle:
+## ---------------------------------------------
+## 1. `create` or `open`        - create a new one or open an existing
+## 2. `storeHeader`             - header info
+## 3. `storePrim` or `storeSeq` - save your stuff
+## 4. `close`                   - and we're done
+##
+## Now read the bits below to understand what's missing.
+##
+## ### Issues with the Example
+## Missing Sections:
+## This is a low level API, so headers and sections need to be stored and
+## loaded by the user, see `storeHeader` & `loadHeader` and `storeSection` &
+## `loadSection`, respectively.
+##
+## No Error Handling:
+## The API is centered around IO and prone to error, each operation checks or
+## sets the `RodFile.err` field. A user of this API needs to handle these
+## appropriately.
+##
+## API Notes
+## =========
+##
+## Valid inputs for Rod files
+## --------------------------
+## ASTs, hopes, dreams, and anything as long as it and any children it may have
+## support `copyMem`. This means anything that is not a pointer and that does not contain a pointer. At a glance these are:
+## * string
+## * objects & tuples (fields are recursed)
+## * sequences AKA `seq[T]`
+##
+## Note on error handling style
+## ----------------------------
+## A flag based approach is used where operations no-op in case of a
+## preexisting error and set the flag if they encounter one.
+##
+## Misc
+## ----
+## * 'Prim' is short for 'primitive', as in a non-sequence type
+
+type
+  RodSection* = enum
+    versionSection
+    configSection
+    stringsSection
+    checkSumsSection
+    depsSection
+    numbersSection
+    exportsSection
+    hiddenSection
+    reexportsSection
+    compilerProcsSection
+    trmacrosSection
+    convertersSection
+    methodsSection
+    pureEnumsSection
+    toReplaySection
+    topLevelSection
+    bodiesSection
+    symsSection
+    typesSection
+    typeInstCacheSection
+    procInstCacheSection
+    attachedOpsSection
+    methodsPerGenericTypeSection
+    enumToStringProcsSection
+    methodsPerTypeSection
+    dispatchersSection
+    typeInfoSection  # required by the backend
+    backendFlagsSection
+    aliveSymsSection # beware, this is stored in a `.alivesyms` file.
+    sideChannelSection
+    namespaceSection
+    symnamesSection
+
+  RodFileError* = enum
+    ok, tooBig, cannotOpen, ioFailure, wrongHeader, wrongSection, configMismatch,
+    includeFileChanged
+
+  RodFile* = object
+    f*: File
+    currentSection*: RodSection # for error checking
+    err*: RodFileError # little experiment to see if this works
+                       # better than exceptions.
+
+const
+  RodVersion = 2
+  defaultCookie = [byte(0), byte('R'), byte('O'), byte('D'),
+            byte(sizeof(int)*8), byte(system.cpuEndian), byte(0), byte(RodVersion)]
+
+proc setError(f: var RodFile; err: RodFileError) {.inline.} =
+  f.err = err
+  #raise newException(IOError, "IO error")
+
+proc storePrim*(f: var RodFile; s: string) =
+  ## Stores a string.
+  ## The len is prefixed to allow for later retreival.
+  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:
+    if s.len != 0:
+      if writeBuffer(f.f, unsafeAddr(s[0]), s.len) != s.len:
+        setError f, ioFailure
+
+proc storePrim*[T](f: var RodFile; x: T) =
+  ## Stores a non-sequence/string `T`.
+  ## If `T` doesn't support `copyMem` and is an object or tuple then the fields
+  ## are written -- the user from context will need to know which `T` to load.
+  if f.err != ok: return
+  when supportsCopyMem(T):
+    if writeBuffer(f.f, unsafeAddr(x), sizeof(x)) != sizeof(x):
+      setError f, ioFailure
+  elif T is tuple:
+    for y in fields(x):
+      storePrim(f, y)
+  elif T is object:
+    for y in fields(x):
+      when y is seq:
+        storeSeq(f, y)
+      else:
+        storePrim(f, y)
+  else:
+    {.error: "unsupported type for 'storePrim'".}
+
+proc storeSeq*[T](f: var RodFile; s: seq[T]) =
+  ## Stores a sequence of `T`s, with the len as a prefix for later retrieval.
+  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 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
+  var lenPrefix = int32(0)
+  if readBuffer(f.f, addr lenPrefix, sizeof(lenPrefix)) != sizeof(lenPrefix):
+    setError f, ioFailure
+  else:
+    s = newString(lenPrefix)
+    if lenPrefix > 0:
+      if readBuffer(f.f, unsafeAddr(s[0]), s.len) != s.len:
+        setError f, ioFailure
+
+proc loadPrim*[T](f: var RodFile; x: var T) =
+  ## Load a non-sequence/string `T`.
+  if f.err != ok: return
+  when supportsCopyMem(T):
+    if readBuffer(f.f, unsafeAddr(x), sizeof(x)) != sizeof(x):
+      setError f, ioFailure
+  elif T is tuple:
+    for y in fields(x):
+      loadPrim(f, y)
+  elif T is object:
+    for y in fields(x):
+      when y is seq:
+        loadSeq(f, y)
+      else:
+        loadPrim(f, y)
+  else:
+    {.error: "unsupported type for 'loadPrim'".}
+
+proc loadSeq*[T](f: var RodFile; s: var seq[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 = newSeq[T](lenPrefix)
+    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
+  if f.f.writeBytes(cookie, 0, cookie.len) != cookie.len:
+    setError f, ioFailure
+
+proc loadHeader*(f: var RodFile; cookie = defaultCookie) =
+  ## Loads the header which is described by `cookie`.
+  if f.err != ok: return
+  var thisCookie: array[cookie.len, byte] = default(array[cookie.len, byte])
+  if f.f.readBytes(thisCookie, 0, thisCookie.len) != thisCookie.len:
+    setError f, ioFailure
+  elif thisCookie != cookie:
+    setError f, wrongHeader
+
+proc storeSection*(f: var RodFile; s: RodSection) =
+  ## update `currentSection` and writes the bytes value of s.
+  if f.err != ok: return
+  assert f.currentSection < s
+  f.currentSection = s
+  storePrim(f, s)
+
+proc loadSection*(f: var RodFile; expected: RodSection) =
+  ## read the bytes value of s, sets and error if the section is incorrect.
+  if f.err != ok: return
+  var s: RodSection = default(RodSection)
+  loadPrim(f, s)
+  if expected != s and f.err == ok:
+    setError f, wrongSection
+
+proc create*(filename: string): RodFile =
+  ## create the file and open it for writing
+  result = default(RodFile)
+  if not open(result.f, filename, fmWrite):
+    setError result, cannotOpen
+
+proc close*(f: var RodFile) = close(f.f)
+
+proc open*(filename: string): RodFile =
+  ## open the file for reading
+  result = default(RodFile)
+  if not open(result.f, filename, fmRead):
+    setError result, cannotOpen
--- a/compiler/icconfig.nim
+++ b/compiler/icconfig.nim
@@ -1,307 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2026 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## Precompiled config for the incremental compiler (`nim ic`).
-##
-## `nim ic` builds the program by spawning one `nim m` child per module (or
-## strongly-connected import group) plus a final `nim nifc`. Each child is a
-## full Nim process, so each would normally re-read the whole `nim.cfg` chain
-## *and* re-run `config.nims` through the VM — work that is identical for every
-## child and, because of the VM run, far from free. With ~85 modules in the
-## compiler itself that config work is paid ~85 times during `koch bootic`.
-##
-## The fix mirrors Nimony's `.cfg.nif`: the driver parses config once, records
-## the net effect, and the children replay it. Every config-file switch funnels
-## through `processSwitch(..., passPP, ...)` (`nimconf.parseAssignment` and the
-## `switch()` callback in `scriptconfig`), so the recorded sequence of those
-## switches, replayed in order, reproduces an identical `ConfigRef` without any
-## file read or VM run. The one config side effect that does not go through
-## `processSwitch` is `cppDefine` (it mutates `conf.cppDefines` directly), so the
-## resolved set is serialised alongside.
-##
-## Path-search switches are deliberately excluded from the recording (see
-## `commands.processSwitch`): their resolved result already lives in
-## `conf.searchPaths`, which the driver forwards to every child as absolute
-## `--path` arguments; replaying their raw, config-dir-relative arguments here
-## would misresolve.
-
-import options, commands, lineinfos, pathutils, msgs
-import std/[algorithm, os, sets, osproc, times, streams, syncio, strutils]
-import "../dist/nimony/src/lib" / [nifbuilder, nifcoreparse]
-
-const
-  IcConfigVersion* = "2"
-    ## Artifact format version. Bump on any layout change here so a child built
-    ## by an older compiler rejects a stale artifact and falls back to normal
-    ## config loading instead of replaying a format it cannot parse.
-
-proc writeIcConfig*(conf: ConfigRef; outfile: string) =
-  ## Serialise the resolved config (the config-file switches recorded during
-  ## `loadConfigs`, the resolved `cppDefines`/`searchPaths`, the nimcache dir, and
-  ## the list of config *source* files for staleness detection) into `outfile`.
-  ## `OnlyIfChanged`: when the content is byte-identical to what is already on
-  ## disk the file is left untouched so its mtime does not advance — otherwise
-  ## every `nim ic` run would re-fire the whole nifmake graph (see `nifler`'s
-  ## `produceConfig`, whose model this mirrors).
-  var b = nifbuilder.open(outfile, writeMode = OnlyIfChanged)
-  b.withTree "stmts":
-    b.withTree "meta":
-      b.addStrLit IcConfigVersion
-    b.withTree "sources":
-      # Every config file read while loading (nim.cfg chain + config.nims), so a
-      # later run can decide via mtimes whether this artifact is still current
-      # (see `sourcesChanged`).
-      for f in conf.configFiles:
-        b.addStrLit f.string
-    b.withTree "nimcache":
-      # Resolved build nimcache. Recorded (unlike the path-search switches) so the
-      # driver, which replays this artifact instead of parsing `nim.cfg`, still
-      # learns a `--nimcache:` set inside `nim.cfg` and builds in the right place.
-      b.addStrLit conf.nimcacheDir.string
-    b.withTree "cppdefines":
-      # HashSet iteration order is unspecified; sort so the artifact is
-      # byte-stable across runs (nifmake keys rebuilds off content changes).
-      var defs: seq[string] = @[]
-      for d in conf.cppDefines: defs.add d
-      sort defs
-      for d in defs: b.addStrLit d
-    b.withTree "searchpaths":
-      # The resolved (absolute) search paths. Path-search *switches* are skipped
-      # below because their raw arguments are config-dir-relative; the net effect
-      # lives here instead, so a replayer with no `--path` command-line arguments
-      # (the `nim ic` driver itself) still resolves imports. `nim m`/`nim nifc`
-      # children also receive these as forwarded `--path` args; the dedup on
-      # replay makes the overlap harmless.
-      for p in conf.searchPaths:
-        b.addStrLit p.string
-    b.withTree "switches":
-      for sw in conf.icConfigSwitches:
-        b.addTree "sw"
-        b.addStrLit sw.switch
-        b.addStrLit sw.arg
-        b.endTree()
-  b.close()
-
-proc applyIcConfig*(conf: ConfigRef; infile: string): bool =
-  ## Replay the precompiled config into `conf`. Returns false (and applies
-  ## nothing meaningful) when the artifact is missing or written by a compiler
-  ## with an incompatible format version, so the caller can fall back to reading
-  ## the config files normally.
-  if not fileExists(infile): return false
-  var pool = newPool()
-  var tags = newTagPool()
-  let
-    stmtsTag = tags.registerTag("stmts")
-    metaTag = tags.registerTag("meta")
-    sourcesTag = tags.registerTag("sources")
-    nimcacheTag = tags.registerTag("nimcache")
-    cppTag = tags.registerTag("cppdefines")
-    pathsTag = tags.registerTag("searchpaths")
-    switchesTag = tags.registerTag("switches")
-    swTag = tags.registerTag("sw")
-  var buf = parseFromFile(infile, 1000, pool, tags)
-  var c = beginRead(buf)
-  if c.kind != TagLit or c.cursorTagId != stmtsTag:
-    endRead(c)
-    return false
-  var version = ""
-  var sawMeta = false
-  let info = unknownLineInfo
-  c.loopInto:
-    if c.kind == TagLit:
-      if c.cursorTagId == metaTag:
-        sawMeta = true
-        c.loopInto:
-          if c.kind == StrLit:
-            version = strVal(c)
-            inc c
-          else:
-            skip c
-      elif c.cursorTagId == nimcacheTag:
-        c.loopInto:
-          if c.kind == StrLit:
-            let nc = strVal(c)
-            # Only when nimcache was not already pinned on the command line: a
-            # `--nimcache:` argument the driver/child was launched with must win
-            # over whatever `nim.cfg` recorded into the artifact.
-            if nc.len > 0 and conf.nimcacheDir.isEmpty:
-              conf.nimcacheDir = AbsoluteDir(nc)
-            inc c
-          else:
-            skip c
-      elif c.cursorTagId == sourcesTag:
-        # Replay does not need the source list; it exists only for
-        # `sourcesChanged`. Skip the whole section.
-        skip c
-      elif c.cursorTagId == cppTag:
-        c.loopInto:
-          if c.kind == StrLit:
-            cppDefine(conf, strVal(c))
-            inc c
-          else:
-            skip c
-      elif c.cursorTagId == pathsTag:
-        c.loopInto:
-          if c.kind == StrLit:
-            # Append preserving the serialised order (which already reflects the
-            # driver's addPath insert-at-front sequence), deduping against any
-            # path a child already received via a forwarded `--path` argument.
-            let d = AbsoluteDir(strVal(c))
-            if not conf.searchPaths.contains(d): conf.searchPaths.add d
-            inc c
-          else:
-            skip c
-      elif c.cursorTagId == switchesTag:
-        c.loopInto:
-          if c.kind == TagLit and c.cursorTagId == swTag:
-            var sw = ""
-            var arg = ""
-            var idx = 0
-            c.loopInto:
-              if c.kind == StrLit:
-                if idx == 0: sw = strVal(c)
-                else: arg = strVal(c)
-                inc idx
-                inc c
-              else:
-                skip c
-            processSwitch(sw, arg, passPP, info, conf)
-          else:
-            skip c
-      else:
-        skip c
-    else:
-      skip c
-  endRead(c)
-  result = sawMeta and version == IcConfigVersion
-
-proc sourcesChanged*(configFile: string): bool =
-  ## True when the precompiled config at `configFile` is missing, malformed,
-  ## written by an incompatible version, or any recorded config *source* file is
-  ## newer than it (or has vanished) — i.e. the artifact must be regenerated.
-  ## Mirrors nifler's `sourcesChanged`: the source list lives inside the artifact
-  ## so this needs no out-of-band knowledge of which `nim.cfg`s were read.
-  if not fileExists(configFile): return true
-  let modtime = getLastModificationTime(configFile)
-  var pool = newPool()
-  var tags = newTagPool()
-  let
-    stmtsTag = tags.registerTag("stmts")
-    metaTag = tags.registerTag("meta")
-    sourcesTag = tags.registerTag("sources")
-  var buf = parseFromFile(configFile, 1000, pool, tags)
-  var c = beginRead(buf)
-  if c.kind != TagLit or c.cursorTagId != stmtsTag:
-    endRead(c)
-    return true
-  var version = ""
-  var depsChanged = false
-  c.loopInto:
-    if c.kind == TagLit and c.cursorTagId == metaTag:
-      c.loopInto:
-        if c.kind == StrLit:
-          version = strVal(c)
-          inc c
-        else:
-          skip c
-    elif c.kind == TagLit and c.cursorTagId == sourcesTag:
-      c.loopInto:
-        if c.kind == StrLit:
-          let dep = strVal(c)
-          if not fileExists(dep) or getLastModificationTime(dep) >= modtime:
-            depsChanged = true
-          inc c
-        else:
-          skip c
-    else:
-      skip c
-  endRead(c)
-  result = depsChanged or version != IcConfigVersion
-
-proc produceIcConfig*(conf: ConfigRef) =
-  ## The `cmdIcConfig` command. By the time it runs, the normal pipeline has
-  ## already fully parsed the `nim.cfg` chain and run `config.nims`, so the
-  ## resolved config is sitting in `conf`; just serialise it to `--o`.
-  let outPath = conf.icConfigOut
-  if outPath.len == 0:
-    rawMessage(conf, errGenerated, "icconfig: missing output path (--icConfigOut)")
-    return
-  createDir(parentDir(outPath))
-  writeIcConfig(conf, outPath)
-
-proc ensureIcConfig*(conf: ConfigRef) =
-  ## Driver-side (`cmdIc`). Make sure an up-to-date precompiled config exists,
-  ## (re)producing it in a *separate* process when missing or stale, then point
-  ## `conf.icPreparsedConfig` at it so the driver replays the very same config its
-  ## `nim m`/`nim nifc` children will — perfect speed (config parsed at most once,
-  ## skipped entirely when nothing changed) and consistency (one producer, every
-  ## process replays its output). The artifact lives in the nimcache derived from
-  ## the command line (pre-config-parse), which is the one the children are told;
-  ## a `--nimcache:` set inside `nim.cfg` is recovered from the artifact itself.
-  let cacheDir = getNimcacheDir(conf).string
-  # Start from a clean cache when the on-disk NIF format stamp is absent or stale
-  # (see `icFormatVersion`). This must happen HERE, before the config artifact is
-  # produced — `commandIc` performs the same check later, but by then the artifact
-  # would already live in the cache and the wipe would delete it.
-  createDir(cacheDir)
-  let versionFile = cacheDir / "ic.version"
-  let stamp = if fileExists(versionFile): readFile(versionFile) else: ""
-  if stamp != icFormatVersion:
-    removeDir(cacheDir)
-    createDir(cacheDir)
-    writeFile(versionFile, icFormatVersion)
-  let outPath = cacheDir / "ic_config.cfg.nif"
-  if not fileExists(outPath) or sourcesChanged(outPath):
-    createDir(cacheDir)
-    # Re-invoke ourselves as the config producer: reuse this process's command
-    # line, dropping the command argument (`ic`/`track`) in favour of `icconfig`
-    # and the explicit output path. Every switch must land BEFORE the project
-    # file, because anything after the project is swallowed into
-    # `config.arguments` by `cmdLineRest` (and a non-empty `arguments` without
-    # `--run` is a hard error). Callers may legitimately put switches after the
-    # project — `nim track PROJ --def:...` — so we re-order rather than replay
-    # verbatim: all `-`-prefixed switches first (in encounter order), then the
-    # non-switch project token(s). The producer re-reads `nim.cfg` itself.
-    var pargs = @["icconfig", "--icConfigOut:" & outPath]
-    # The command token is dropped below, so `nim cpp --ic:on` would hand the
-    # producer a C-backend config: name the backend explicitly. (`nim ic
-    # --backend:cpp` already carries the switch; the duplicate is harmless.)
-    if conf.backend != backendInvalid:
-      pargs.add "--backend:" & $conf.backend
-    var rest: seq[string] = @[]
-    var droppedCmd = false
-    for a in commandLineParams():
-      if a.len == 0: continue
-      if a[0] == '-':
-        # `--run`/`-r` must not reach the producer: it only serialises the
-        # resolved config, has no output binary, and `nim.nim`'s run step asserts
-        # on the empty `outFile` (`nim cpp --ic:on -r foo.nim`).
-        var name = ""
-        var i = 1
-        if i < a.len and a[i] == '-': inc i
-        while i < a.len and a[i] notin {':', '='}:
-          name.add a[i]
-          inc i
-        if normalize(name) in ["r", "run"]: continue
-        pargs.add a
-      elif not droppedCmd:
-        droppedCmd = true  # drop the original command token (`ic`/`track`)
-      else:
-        rest.add a  # project file (and any further non-switch tokens) go last
-    for a in rest: pargs.add a
-    let p = startProcess(getAppFilename(), args = pargs,
-                         options = {poStdErrToStdOut})
-    let outp = p.outputStream.readAll()
-    let code = p.waitForExit()
-    p.close()
-    if code != 0 or not fileExists(outPath):
-      rawMessage(conf, errGenerated,
-        "failed to produce precompiled config (exit code " & $code & "):\n" & outp)
-      return
-  conf.icPreparsedConfig = outPath
--- a/compiler/icmodnames.nim
+++ b/compiler/icmodnames.nim
@@ -1,55 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2026 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## Nim's OWN module-suffix, replacing nimony's `gear2/modnames.moduleSuffix`.
-##
-## nimony's version hashes a path made RELATIVE to `getCurrentDir()` (or the
-## shortest search-path-relative form), so the produced suffix depends on the
-## current working directory AND the searchPath set. Under `nim ic` the
-## DISCOVERY pass (`deps.nim`, in the driver process) and the COMPILE pass
-## (`nifgen`/`typekeys`, in a child `nim m` process) can run with different CWDs
-## or `--path` sets, so the SAME file hashes to two different suffixes: e.g.
-## `std/staticos` became `sta5rk8sn1` at discovery but `sta4c0qxk` at compile, so
-## every importer waited forever for a `.s.bif` that was actually written under
-## the other name — a cold `nim ic` build (of anything pulling in `std/os`, whose
-## `oscommon` does `from std/staticos import PathComponent`) never converged.
-##
-## Hashing the CANONICAL ABSOLUTE path makes the suffix a pure function of the
-## file, identical across every process and call site. The base-name prefix +
-## base-36 `uhash` layout is kept byte-for-byte compatible with the old scheme so
-## nothing but the hashed string changes.
-
-import std/os
-import "../dist/nimony/src/lib" / tinyhashes
-
-const
-  PrefixLen = 3 # keep it short: the suffix ends up in every mangled C name
-  Base36 = "0123456789abcdefghijklmnopqrstuvwxyz"
-
-proc moduleSuffix*(path: string; searchPaths: openArray[string]): string =
-  ## `searchPaths` is accepted for signature-compatibility with the replaced
-  ## `modnames.moduleSuffix` but is deliberately IGNORED — the suffix must not
-  ## depend on the search-path set or the CWD (see the module doc).
-  # Absolute inputs (the norm at every call site: `toFullPath`/`projectFull`)
-  # pass straight through `normalizedPath` with no `getCurrentDir` involvement;
-  # a stray relative path is made absolute against the CWD only as a fallback.
-  var f = path
-  if not isAbsolute(f):
-    try: f = absolutePath(f)
-    except CatchableError: discard
-  f = normalizedPath(f)
-  let m = splitFile(f).name
-  var id = uhash(f)
-  result = newStringOfCap(10)
-  for i in 0 ..< min(m.len, PrefixLen):
-    result.add m[i]
-  # base-36 of the hash, low digit first (order is irrelevant for identity).
-  while id > 0'u32:
-    result.add Base36[int(id mod 36'u32)]
-    id = id div 36'u32
--- a/compiler/icnifcore.nim
+++ b/compiler/icnifcore.nim
@@ -1,252 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2026 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## nifcore-based IC serialization helpers — Stage 1 of porting the IC backend
-## from the old `nifstreams`/`nifcursors` NIF stack to `nifcore` (see
-## `doc/ic_nifcore_port.md`).
-##
-## It hosts:
-## * the process-wide shared `Pool`/`TagPool` that stands in for the old global
-##   `nifstreams.pool`,
-## * `writeFileStable`, the content-stable file writer mirroring
-##   `nifcursors.writeFile(..., OnlyIfChanged)`,
-## * the first ported writer (`writeSemDeps`), used as the migration spike.
-##
-## No `nifstreams`/`nifcursors` types cross this module's boundary: callers pass
-## plain Nim values (config, ids, string lists), so it can coexist with the
-## still-old-API `ast2nif.nim` during the migration.
-
-import std / [syncio, algorithm]
-from std / os import removeFile, moveFile
-import options, pathutils, typekeys
-import "../dist/nimony/src/lib" / [nifcore, nifcoreparse, nifreader, bif]
-
-# One shared literals pool + tag pool for the whole process — the nifcore
-# analogue of the old global `nifstreams.pool`. A single shared pool keeps
-# string/symbol/file ids stable across every TokenBuf the IC backend builds,
-# preserving the old global-pool semantics during the migration. (Stage 6 may
-# move to fresh per-file pools for bif's fast path; see doc/ic_nifcore_port.md.)
-let icPool* = newPool()
-let icTags* = newTagPool()
-
-proc createIcBuf*(cap = 16): TokenBuf {.inline.} =
-  ## A `TokenBuf` bound to the shared IC pools.
-  createTokenBuf(cap, icPool, icTags)
-
-proc tagId*(s: string): TagId {.inline.} =
-  ## Intern a tag name in the shared tag pool.
-  icTags.registerTag(s)
-
-type
-  IcBuilder* = object
-    ## A thin nifcore `TokenBuf` builder whose surface is *primitive types only*
-    ## (strings/ints/floats). It lets the still-old-API `ast2nif.nim` drive a
-    ## nifcore buffer without any nifcore type crossing the module boundary —
-    ## the bridge that routes IC output onto the nifcore serializer (Stage 2).
-    buf*: TokenBuf
-
-proc newIcBuilder*(cap = 16): IcBuilder = IcBuilder(buf: createIcBuf(cap))
-
-proc openTag*(b: var IcBuilder; tag: string) {.inline.} = b.buf.openTag(tagId(tag))
-proc closeTag*(b: var IcBuilder) {.inline.} = b.buf.closeTag()
-proc addSymUse*(b: var IcBuilder; s: string) {.inline.} = b.buf.addSymUse(s)
-proc addSymDef*(b: var IcBuilder; s: string) {.inline.} = b.buf.addSymDef(s)
-proc addIdent*(b: var IcBuilder; s: string) {.inline.} = b.buf.addIdent(s)
-proc addStrLit*(b: var IcBuilder; s: string) {.inline.} = b.buf.addStrLit(s)
-proc addIntLit*(b: var IcBuilder; v: int64) {.inline.} = b.buf.addIntLit(v)
-proc addUIntLit*(b: var IcBuilder; v: uint64) {.inline.} = b.buf.addUIntLit(v)
-proc addFloatLit*(b: var IcBuilder; v: float64) {.inline.} = b.buf.addFloatLit(v)
-proc addCharLit*(b: var IcBuilder; c: char) {.inline.} = b.buf.addCharLit(c)
-proc addDotToken*(b: var IcBuilder) {.inline.} = b.buf.addDotToken()
-
-proc lineInfo*(b: var IcBuilder; file: string; line, col: int32; comment = "") =
-  ## Attach line info (+ optional `#comment#`) to the head just emitted. No-op
-  ## when `file` is empty (matches the old "emit only when info is valid").
-  ## Strings are interned in the shared pools; the file/comment ids reproduce
-  ## the old `pool.files`/`pool.strings` entries by string value.
-  if file.len == 0: return
-  let fid = icPool.filenames.getOrIncl(file)
-  let cid = if comment.len > 0: icPool.strings.getOrIncl(comment) else: StrId(0)
-  b.buf.appendLineInfo(fid, line, col, cid)
-
-proc writeFileStable*(b: var TokenBuf; path: string; onlyIfChanged = false) =
-  ## Serialize `b` to canonical module NIF text and write it. Mirrors
-  ## `nifcursors.writeFile`: the module suffix is derived from `path`
-  ## (`"." & extractModuleSuffix`), and `onlyIfChanged` skips the write when the
-  ## on-disk bytes already match — the content-stability nifmake's incremental
-  ## rebuild depends on.
-  let content = toModuleString(b, "." & extractModuleSuffix(path))
-  if onlyIfChanged:
-    let existing =
-      try: readFile(path)
-      except CatchableError: ""
-    if existing == content: return
-  writeFile(path, content)
-
-proc writeStable*(b: var IcBuilder; path: string; onlyIfChanged = false) {.inline.} =
-  writeFileStable(b.buf, path, onlyIfChanged)
-
-proc cursorPool*(c: Cursor): Pool {.inline.} = nifcore.pool(c)
-  ## The literals pool the cursor's buffer was built against. `ast2nif.nim`
-  ## imports `nifcore` with `except pool` (to keep nifstreams' global `pool`
-  ## var the writer uses), so the reader reaches a cursor's pool through here —
-  ## needed once `bif`-loaded buffers carry their OWN fresh pool rather than the
-  ## shared `icPool`.
-
-proc freshModuleCopy(b: var IcBuilder): TokenBuf =
-  ## Re-home `b.buf` into a PRIVATE, module-local pool via `addSubtree` (which
-  ## re-interns only the literals/tags this buffer actually uses). `b.buf` is bound
-  ## to the process-wide shared `icPool`/`icTags`; storing it directly would embed
-  ## the WHOLE shared pool (correct but huge — see `bif.storeToFile`). The copy's
-  ## fresh-pool reload reproduces ids verbatim (the bif fresh-pool INVARIANT).
-  result = createTokenBuf(b.buf.len, newPool(), newTagPool())
-  var c = b.buf.beginRead()
-  while c.hasMore:
-    addSubtree(result, c)
-    skip c
-
-proc storeBif*(b: var IcBuilder; path: string; dottedSuffix: string) =
-  ## Persist the buffer as a compact, self-contained binary NIF (`.bif`).
-  var fresh = freshModuleCopy(b)
-  bif.store(fresh, path, dottedSuffix)
-
-proc storeBifStable*(b: var IcBuilder; path: string; dottedSuffix: string) =
-  ## Content-stable `bif` write — the binary analogue of `writeFileStable`'s
-  ## `onlyIfChanged`: only replace `path` when the encoded bytes differ, so an
-  ## unchanged sidecar keeps its mtime and nifmake prunes the dependent rebuild
-  ## cascade. Used for the iface/impl cookies + dep sidecars whose byte-stability
-  ## gates incremental builds. (bif encoding is deterministic for a given buffer
-  ## under fresh pools, so equal content ⇒ equal bytes.)
-  var fresh = freshModuleCopy(b)
-  let tmp = path & ".tmp"
-  bif.store(fresh, tmp, dottedSuffix)
-  let newBytes = readFile(tmp)
-  let oldBytes =
-    try: readFile(path)
-    except CatchableError: ""
-  if newBytes == oldBytes:
-    removeFile(tmp)
-  else:
-    moveFile(tmp, path)
-
-# --- subtree splicing (shared pool, so a raw subtree copy is exact) ----------
-
-proc addAll*(dest: var IcBuilder; src: var IcBuilder) =
-  ## Append every top-level subtree of `src` into `dest` — the nifcore analogue
-  ## of the old `dest.add wholeBuffer` splice.
-  var c = src.buf.beginRead()
-  while c.hasMore:
-    addSubtree(dest.buf, c)
-    skip c
-
-proc addStmtsBody*(dest: var IcBuilder; src: var IcBuilder) =
-  ## Append the BODY of a `(stmts . . <body> )` builder into `dest`, dropping the
-  ## wrapper tag and its two leading dot slots (flags/type) — the nifcore
-  ## analogue of the old `for i in 3 ..< content.len-1: dest.add content[i]`.
-  var c = src.buf.beginRead()   # at (stmts
-  c.into:
-    skip c   # flags dot
-    skip c   # type dot
-    while c.hasMore:
-      addSubtree(dest.buf, c)
-      skip c
-
-# --- cookie input: a line-info-free logical token list of the module ---------
-# The cookie hashers (ast2nif) need a flat, ParRi-bearing, index-addressable
-# view of the serialized module. nifcore has no ParRi kind and variable-width
-# tokens, so we flatten the buffer here (in the clean nifcore world) into a
-# neutral `CookieTok` list — no nifcore type crosses into ast2nif.
-
-type
-  CookieKind* = enum
-    ckParLe, ckParRi, ckSym, ckSymDef, ckIdent, ckStr, ckInt, ckUInt, ckFloat, ckChar, ckDot
-  CookieTok* = object
-    kind*: CookieKind
-    tag*: string       # ckParLe
-    name*: string      # ckSym / ckSymDef
-    sym*: uint32       # ckSym / ckSymDef id (identity key)
-    str*: string       # ckIdent / ckStr
-    ival*: int64
-    uval*: uint64
-    fval*: float64
-    cval*: uint32
-
-proc flattenGo(c: var Cursor; b: TokenBuf; acc: var seq[CookieTok]) =
-  while c.hasMore:
-    case c.kind
-    of TagLit:
-      acc.add CookieTok(kind: ckParLe, tag: b.tags.tagName(c.cursorTagId))
-      c.into:
-        flattenGo(c, b, acc)
-      acc.add CookieTok(kind: ckParRi)
-    of Symbol:
-      acc.add CookieTok(kind: ckSym, name: symName(c, b.pool), sym: uint32(symId(c, b.pool)))
-      skip c
-    of SymbolDef:
-      acc.add CookieTok(kind: ckSymDef, name: symName(c, b.pool), sym: uint32(symId(c, b.pool)))
-      skip c
-    of Ident:
-      acc.add CookieTok(kind: ckIdent, str: strVal(c, b.pool)); skip c
-    of StrLit:
-      acc.add CookieTok(kind: ckStr, str: strVal(c, b.pool)); skip c
-    of IntLit:
-      acc.add CookieTok(kind: ckInt, ival: intVal(c)); skip c
-    of UIntLit:
-      acc.add CookieTok(kind: ckUInt, uval: uintVal(c)); skip c
-    of FloatLit:
-      acc.add CookieTok(kind: ckFloat, fval: floatVal(c)); skip c
-    of CharLit:
-      acc.add CookieTok(kind: ckChar, cval: uint32(ord(charLit(c)))); skip c
-    of DotToken:
-      acc.add CookieTok(kind: ckDot); skip c
-    else:
-      skip c   # LineInfoLit / ExtendedSuffix ride on heads, never standalone
-
-proc flattenForCookie*(b: var IcBuilder): seq[CookieTok] =
-  ## Flatten the nifcore module buffer to the cookie hashers' flat token list.
-  result = newSeqOfCap[CookieTok](b.buf.len)
-  var cur = b.buf.beginRead()
-  flattenGo(cur, b.buf, result)
-
-proc collectBifStrLits*(path: string): seq[string] =
-  ## Read a small `(tag "s" "s" …)` bif sidecar (`semdeps`/`edges`) and return every
-  ## string literal it holds, in order — the binary analogue of the old nifstreams
-  ## scan that collected `StrLit`s. Keeps nifcore types out of `deps.nim`, which
-  ## only needs the recorded string list.
-  ##
-  ## Uses `loadFromFile` (a full read into owned memory) rather than the mmap-backed
-  ## `bif.load`, then CLOSES the handle. `bif.load` intentionally leaves the mapping
-  ## resident for the process lifetime; for the `nim ic` driver that reads these
-  ## sidecars while `nim m` children rewrite them, a lingering read mapping is a
-  ## Windows sharing violation: the child's `open(path, fmWrite)` fails with
-  ## `IOError: cannot open`. These sidecars are tiny, so the zero-copy mmap buys
-  ## nothing here anyway.
-  result = @[]
-  var f = open(path, fmRead)
-  var m = bif.loadFromFile(f)
-  close(f)
-  var c = m.buf.beginRead()
-  while c.hasMore:
-    if c.kind == StrLit: result.add strVal(c)
-    inc c
-
-proc writeSemDeps*(config: ConfigRef; thisModule: int32; importPaths: seq[string]) =
-  ## Stage 1 spike: the nifcore port of `ast2nif.writeSemDeps`. Serializes the
-  ## module's resolved direct imports as `(semdeps "path" ...)`. Byte-identical
-  ## to the old writer (verified), so `nim ic` build graphs are unaffected.
-  let selfSuffix = modname(thisModule, config)
-  var paths = importPaths
-  sort paths
-  var dest = newIcBuilder(4 + 2*paths.len)
-  dest.openTag "semdeps"
-  for p in paths:
-    dest.addStrLit p
-  dest.closeTag()
-  let path = toGeneratedFile(config, AbsoluteFile(selfSuffix), ".s.deps.bif").string
-  storeBifStable(dest, path, "." & extractModuleSuffix(path))
--- a/compiler/icprof.nim
+++ b/compiler/icprof.nim
@@ -1,83 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2026 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## Opt-in instrumentation for the IC backend, enabled with `-d:icBNodeProf`.
-## Off, every template below is `discard` and nothing is linked in.
-##
-## It lives in its own module with NO compiler imports so that any stage can
-## use it without creating a cycle — `bnode` needs it for the accessors,
-## `nifbackend` for the stage phases, `cgen` for what happens per routine.
-##
-## Each backend process appends ONE line to `$NIM_IC_BNODE_PROF` at exit (or to
-## stderr when that is unset), because a `--ic:on` build fans out a process per
-## module per stage and interleaved writes would tear. Use `-d:icNoParallel`
-## when the numbers need to be attributable to a particular module.
-##
-## Counts are for volume, timings for cost, and the two answer different
-## questions: the accessors turned out to be 700k calls worth 8ms, while `info`
-## was 259k calls worth 1.36s. Neither number alone would have found that.
-
-when defined(icBNodeProf):
-  import std / [envvars, exitprocs, syncio, monotimes]
-  from std / times import inNanoseconds
-
-  type
-    ProfSlot* = enum
-      pKind, pTagKindHit, pTagKindMiss, pAstChildren, pSkip, pSon, pLen,
-      pLastSon, pIterYield, pSym, pTyp, pTypTagLit, pOrigin, pNilType,
-      pGenBodyCalls, pInfo, pIfaceExported, pIfaceHidden, pIfaceModules,
-      pTopNodes, pExportSyms, pPeekKind, pPeekFallback, pPeekLoaded
-    TimeSlot* = enum
-      tLoadClosure, tModuleId, tBifLoad, tPosIndex, tTopLevel, tInterfTables,
-      tTransform, tHandOff, tGenBody, tAnalyses,
-      tSym, tTyp, tInfo, tOrigin, tExportBranch, tResolveSym, tEnumFields
-
-  var profCounts: array[ProfSlot, int]
-  var profNanos: array[TimeSlot, int64]
-  var profStart: array[TimeSlot, MonoTime]
-  var profArmed = false
-
-  proc profDump() =
-    var line = "BNODEPROF"
-    for s in ProfSlot: line.add " " & ($s)[1..^1] & "=" & $profCounts[s]
-    for s in TimeSlot: line.add " " & ($s)[1..^1] & "ms=" & $(profNanos[s] div 1_000_000)
-    let f = getEnv("NIM_IC_BNODE_PROF")
-    if f.len > 0:
-      let h = open(f, fmAppend)
-      h.writeLine line
-      h.close()
-    else:
-      stderr.writeLine line
-
-  template armProf() =
-    if not profArmed:
-      profArmed = true
-      addExitProc profDump
-
-  template prof*(s: ProfSlot; n = 1) =
-    armProf()
-    inc profCounts[s], n
-  template icProfStart*(s: TimeSlot) =
-    armProf()
-    profStart[s] = getMonoTime()
-  template icProfStop*(s: TimeSlot) =
-    profNanos[s] += (getMonoTime() - profStart[s]).inNanoseconds
-
-  template timed*(s: TimeSlot; body: untyped) =
-    ## Leaf timing. NOT re-entrant, and the phase slots are not disjoint —
-    ## `tTransform` contains body materialization, `tTyp` reaches `tSym`. Read
-    ## them as nested, not additive.
-    let t0 = getMonoTime()
-    body
-    profNanos[s] += (getMonoTime() - t0).inNanoseconds
-else:
-  template prof*(s: untyped; n = 1) = discard
-  template icProfStart*(s: untyped) = discard
-  template icProfStop*(s: untyped) = discard
-  template timed*(s: untyped; body: untyped) = body
--- a/compiler/idetools.nim
+++ b/compiler/idetools.nim
@@ -1,279 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2026 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## NIF-based goto-definition / find-all-usages for `nim track`.
-##
-## This is the mainline-Nim port of nimony's `idetools.nim`. It answers a
-## `--def:FILE,LINE,COL` / `--usages:FILE,LINE,COL` query by *scanning the
-## `.s.bif` files* (binary NIF, see `dist/nimony/src/lib/bif.nim`) that the
-## preceding `nim ic` frontend (`nim track`) emitted into the nimcache directory
-## — NOT by re-running sem. NIF distinguishes a definition (`SymbolDef` token) from a use
-## (`Symbol` token) syntactically, so goto-def / find-uses become plain token
-## scans over type-checked NIF, which is more reliable than the classic PSym
-## engine because generics and macros are type-checked in the NIF too.
-##
-## Two passes (mirroring nimony's `usages`):
-##  1. Load the queried module's `.s.bif` and find the `Symbol`/`SymbolDef`
-##     token whose line info + identifier length contains `conf.m.trackPos`.
-##     That yields the mangled symbol NAME and whether it is global (>= 2 dots).
-##  2. `--usages`: emit every `Symbol` (use) token; `--def`: every `SymbolDef`.
-##     A global symbol is scanned across every module `.s.bif`; a local one only
-##     within the queried module.
-##
-## IMPORTANT porting note: `bif.load` mints FRESH per-file pools, so a `SymId`
-## from module A's buffer is meaningless in module B's. The cross-module match is
-## therefore by the mangled NAME string, never by `SymId` (nimony can compare ids
-## because it parses every text NIF into one shared global pool; we cannot).
-
-import std / [os, strutils, sets]
-import options, msgs, pathutils
-import lineinfos as astli
-import ast2nif   # toNifFilename
-from deps import includerSbifs   # deps-guided include-file lookup
-import "../dist/nimony/src/lib/nifcore"
-from "../dist/nimony/src/lib" / bif import load, BifModule, containsSym
-
-proc identLen(name: string): int =
-  ## Length of the displayed identifier: the run before the first `.` of a
-  ## mangled NIF name (`ident.disamb[.moduleSuffix]`). Bounds the column match.
-  let d = name.find('.')
-  result = if d < 0: name.len else: d
-
-proc isGlobalName(name: string): bool =
-  ## A global symbol carries `ident.disamb.moduleSuffix` (>= 2 dots); a local at
-  ## most `ident.disamb` (<= 1 dot). `moduleSuffix` is a dot-free hash, so a raw
-  ## dot count is equivalent to nifbuilder's suffix-compressed test for our use.
-  var dots = 0
-  for i in 1 ..< name.len:
-    if name[i] == '.': inc dots
-  result = dots >= 2
-
-proc posMatch(c: Cursor; conf: ConfigRef; target: TLineInfo; tokenLen: int): bool =
-  ## True when `target` (the queried position) falls within the identifier span
-  ## of the Symbol/SymbolDef token at `c`. Mirrors nimony's `lineInfoMatch`; the
-  ## filename is resolved through the loaded buffer's own pool (fresh per file),
-  ## then mapped to a `FileIndex` exactly like `ast2nif.oldLineInfo`.
-  let li = rawLineInfo(c)
-  if not li.isValid: return false
-  if li.line.int != target.line.int: return false
-  let f = fileInfoIdx(conf, AbsoluteFile lineInfoFile(c))
-  if f != target.fileIndex: return false
-  if target.col.int < li.col.int: return false
-  if target.col.int > li.col.int + tokenLen: return false
-  result = true
-
-const sep = '\t'
-
-proc formatSuggest(s: Suggest): string =
-  ## Reproduce `suggest.$Suggest` for the `ideDef`/`ideUse` sections without
-  ## importing `suggest` (which would create an import cycle). Layout:
-  ## `section⭾symkind⭾qualifiedPath⭾forth⭾filePath⭾line⭾column⭾⭾quality`.
-  ## symkind is always `skUnknown` here — the raw NIF scan has no PSym to give a
-  ## real kind (like nimony's `foundSymbol`, which leaves it empty).
-  result = $s.section
-  result.add sep
-  result.add "skUnknown"
-  result.add sep
-  if s.qualifiedPath.len != 0:
-    result.add s.qualifiedPath.join(".")
-  result.add sep
-  result.add s.forth
-  result.add sep
-  result.add s.filePath
-  result.add sep
-  result.add $s.line
-  result.add sep
-  result.add $s.column
-  result.add sep            # empty doc field (docgen is off outside nimsuggest)
-  if s.version == 0 or s.version == 3:
-    result.add sep
-    result.add $s.quality
-
-proc emit(conf: ConfigRef; c: Cursor; section: IdeCmd; name: string;
-          seen: var HashSet[string]) =
-  ## Report one hit as a nimsuggest-compatible result (routed through the
-  ## structured-output hook / `--stdout`). We only have the mangled name + line
-  ## info from the raw NIF, so symkind/type are left empty — like nimony's
-  ## `foundSymbol`. `seen` deduplicates: the same source location can back
-  ## several NIF `Symbol` tokens (e.g. a call argument re-emitted in a lowered
-  ## form), which must surface as one hit.
-  let li = rawLineInfo(c)
-  if not li.isValid: return
-  let key = $section.int & ":" & lineInfoFile(c) & ":" & $li.line.int & ":" & $li.col.int
-  if seen.containsOrIncl(key):
-    return  # already reported this location for this section
-  let s = Suggest(section: section,
-                  qualifiedPath: @[name[0 ..< identLen(name)]],
-                  filePath: lineInfoFile(c),
-                  line: li.line.int,
-                  column: li.col.int,
-                  tokenLen: identLen(name),
-                  forth: "",
-                  symkind: 0'u8,
-                  quality: 100,
-                  version: conf.suggestVersion)
-  if conf.suggestionResultHook != nil:
-    conf.suggestionResultHook(s)
-  else:
-    conf.suggestWriteln(formatSuggest(s))
-
-proc tokenSymId(c: Cursor): SymId {.inline.} =
-  ## SymId (in the cursor's own per-file pool) of a `Symbol`/`SymbolDef` token,
-  ## or `SymId(0)` for an inline-encoded one — which is never our search target:
-  ## a mangled name (`ident.disamb.suffix`) is always longer than
-  ## `StrInlineMaxLen`, so every occurrence of the symbol we look for is stored by
-  ## pool id, decoded here with a shift and no string materialization.
-  if isInlineLit(c): SymId(0) else: SymId(combinedPayload(c) shr 1)
-
-template symMatches(c: Cursor): bool =
-  ## True when the token at `c` is the searched symbol. The fast path is a pure
-  ## integer compare against `targetSym` (the symbol's id in THIS module's pool,
-  ## resolved once per file by the caller). `targetSym == 0` means the name is not
-  ## representable as a pool id (a rare <=3-byte local): fall back to a string
-  ## compare, correct for both inline and pooled encodings.
-  (if targetSym != SymId(0): tokenSymId(c) == targetSym else: symName(c) == targetName)
-
-proc scanUses(conf: ConfigRef; m: var BifModule; targetSym: SymId; targetName: string;
-              seen: var HashSet[string]) =
-  ## `--usages`: report every `Symbol` (use) occurrence with valid line info.
-  if m.buf.len == 0: return
-  var c = m.buf.beginRead()
-  while c.hasMore:
-    if c.kind == Symbol and symMatches(c) and rawLineInfo(c).isValid:
-      emit(conf, c, ideUse, targetName, seen)
-    inc c
-  c.endRead()
-
-proc scanDef(conf: ConfigRef; m: var BifModule; targetSym: SymId; targetName: string;
-             seen: var HashSet[string]) =
-  ## `--def`: report the declaration of the target symbol if this module owns it
-  ## (has its `SymbolDef`). The `SymbolDef` token itself carries no line info; the
-  ## declaration location lives on the *enclosing tag* (e.g. `(sd @file:line:col`,
-  ## like `bif.buildIndex`'s `mostRecentTagPos`). When that tag has no line info
-  ## either, fall back to the declaration-site `Symbol` occurrence — but only in
-  ## the owning module, so a plain user of the symbol is never reported as a def.
-  if m.buf.len == 0: return
-  var c = m.buf.beginRead()
-  var mostRecentTagPos = 0
-  var sawDef = false
-  var emitted = false
-  var fallbackPos = -1
-  while c.hasMore:
-    case c.kind
-    of TagLit:
-      mostRecentTagPos = cursorToPosition(m.buf, c)
-      inc c
-    of SymbolDef:
-      if symMatches(c):
-        sawDef = true
-        var tc = cursorAt(m.buf, mostRecentTagPos)
-        if rawLineInfo(tc).isValid:
-          emit(conf, tc, ideDef, targetName, seen)
-          emitted = true
-        tc.endRead()
-      inc c
-    of Symbol:
-      if fallbackPos < 0 and symMatches(c) and rawLineInfo(c).isValid:
-        fallbackPos = cursorToPosition(m.buf, c)
-      inc c
-    else:
-      inc c
-  c.endRead()
-  if sawDef and not emitted and fallbackPos >= 0:
-    var fc = cursorAt(m.buf, fallbackPos)
-    emit(conf, fc, ideDef, targetName, seen)
-    fc.endRead()
-
-proc scanBuf(conf: ConfigRef; m: var BifModule; section: IdeCmd;
-             targetSym: SymId; targetName: string; seen: var HashSet[string]) =
-  ## Emit hits for the target symbol in `m` per the query kind. `ideDus`
-  ## (`--defusages`) reports both the definition and every usage.
-  if section in {ideDef, ideDus}:
-    scanDef(conf, m, targetSym, targetName, seen)
-  if section in {ideUse, ideDus}:
-    scanUses(conf, m, targetSym, targetName, seen)
-
-proc findPos(conf: ConfigRef; m: var BifModule; target: TLineInfo;
-             foundName: var string): bool =
-  ## Scan `m` for the `Symbol`/`SymbolDef` token covering the queried position
-  ## `target` and set `foundName` to its mangled name. Returns true on a hit.
-  if m.buf.len == 0: return false
-  var c = m.buf.beginRead()
-  result = false
-  while c.hasMore:
-    let k = c.kind
-    if k == Symbol or k == SymbolDef:
-      let nm = symName(c)
-      if posMatch(c, conf, target, identLen(nm)):
-        foundName = nm
-        result = true
-        break
-    inc c
-  c.endRead()
-
-proc runIdeQuery*(conf: ConfigRef) =
-  ## Entry point: called from `main.nim` after `commandCheck` when a
-  ## `--def`/`--usages` query is active. Assumes the check just emitted the
-  ## project's `.s.bif` files into `getNimcacheDir(conf)`.
-  let section = conf.ideCmd
-  if section notin {ideDef, ideUse, ideDus}: return
-  let target = conf.m.trackPos
-  if target.fileIndex.int32 < 0: return
-
-  # Pass 1: position -> symbol. Try the queried file's own module bif first (the
-  # fast path when the position is inside a real module). An include file has no
-  # module bif of its own — its tokens live in the *including* module's bif with
-  # include-file line info — so when the direct lookup misses, consult the
-  # `.deps.nif` preludes (`includerSbifs`) to load only the module(s) that
-  # include the queried file (directly or transitively), never every bif in the
-  # nimcache. `ownerFile` is the bif that owns the hit.
-  let modFile = toNifFilename(conf, target.fileIndex)
-  var foundName = ""
-  var ownerFile = ""
-  if fileExists(modFile):
-    var qm = load(modFile)
-    if findPos(conf, qm, target, foundName):
-      ownerFile = modFile
-  if foundName.len == 0:
-    for cand in includerSbifs(conf, toFullPath(conf, target.fileIndex).AbsoluteFile):
-      if cand == modFile: continue
-      var m = load(cand)
-      if findPos(conf, m, target, foundName):
-        ownerFile = cand
-        break
-  if foundName.len == 0: return
-
-  # Pass 2: emit definition / usages. `seen` spans every module so a location is
-  # reported once even when scanned across the whole nimcache.
-  #
-  # Cross-file matching is by SymId, not by decoding every token's name. Two
-  # filters keep it cheap:
-  #   1. `bif.containsSym` — a sym-table-only probe that reads just the small
-  #      trailing pools, NOT the token block or any `BiTable`. A module that never
-  #      references the symbol is rejected here without a full `load` (no pools
-  #      built, no token block mapped) — so a query whose symbol lives in a few
-  #      modules no longer pays to load the whole nimcache.
-  #   2. For a module that does contain it, `bif.load` mints a fresh per-file pool,
-  #      so the name is resolved to THIS file's SymId once via `getKeyId`; the scan
-  #      then compares integer ids per token instead of materializing a string for
-  #      each (see `symMatches`).
-  var seen = initHashSet[string]()
-  if isGlobalName(foundName):
-    for f in walkFiles((getNimcacheDir(conf).string) / "*.s.bif"):
-      if not containsSym(f, foundName): continue
-      var m = load(f)
-      let tid = m.buf.pool.syms.getKeyId(foundName)
-      if tid != SymId(0):
-        scanBuf(conf, m, section, tid, foundName, seen)
-  else:
-    # Local symbol: its mangled name is not unique across modules, so restrict
-    # the scan to the module it lives in (the one that owns the queried position).
-    var qm = load(ownerFile)
-    let tid = qm.buf.pool.syms.getKeyId(foundName)
-    scanBuf(conf, qm, section, tid, foundName, seen)
--- a/compiler/importer.nim
+++ b/compiler/importer.nim
@@ -10,10 +10,10 @@
 ## This module implements the symbol importing mechanism.

 import
-  ast, msgs, options, idents, lookups,
+  ast, astalgo, msgs, options, idents, lookups,
  semdata, modulepaths, sigmatch, lineinfos,
  modulegraphs, wordrecg
-from std/strutils import `%`, startsWith, replace
+from std/strutils import `%`, startsWith
 from std/sequtils import addUnique
 import std/[sets, tables, intsets]

@@ -108,8 +108,8 @@ proc rawImportSymbol(c: PContext, s, origin: PSym; importSet: var IntSet) =
          else:
            importPureEnumField(c, e)
  else:
-    if s.kind == skConverter: addConverter(c, s)
-    if hasPattern(s): addPattern(c, s)
+    if s.kind == skConverter: addConverter(c, LazySym(sym: s))
+    if hasPattern(s): addPattern(c, LazySym(sym: s))
  if s.owner != origin:
    c.exportIndirections.incl((origin.id, s.id))

@@ -190,19 +190,22 @@ proc addImport(c: PContext; im: sink ImportedModule) =
 template addUnnamedIt(c: PContext, fromMod: PSym; filter: untyped) {.dirty.} =
  for it in mitems c.graph.ifaces[fromMod.position].converters:
    if filter:
-      if sfExported in it.flags:
+      loadPackedSym(c.graph, it)
+      if sfExported in it.sym.flags:
        addConverter(c, it)
  for it in mitems c.graph.ifaces[fromMod.position].patterns:
    if filter:
-      if sfExported in it.flags:
+      loadPackedSym(c.graph, it)
+      if sfExported in it.sym.flags:
        addPattern(c, it)
  for it in mitems c.graph.ifaces[fromMod.position].pureEnums:
    if filter:
-      importPureEnumFields(c, it, it.typ)
+      loadPackedSym(c.graph, it)
+      importPureEnumFields(c, it.sym, it.sym.typ)

 proc importAllSymbolsExcept(c: PContext, fromMod: PSym, exceptSet: IntSet) =
  c.addImport ImportedModule(m: fromMod, mode: importExcept, exceptSet: exceptSet)
-  addUnnamedIt(c, fromMod, it.name.id notin exceptSet)
+  addUnnamedIt(c, fromMod, it.sym.name.id notin exceptSet)

 proc importAllSymbols*(c: PContext, fromMod: PSym) =
  c.addImport ImportedModule(m: fromMod, mode: importAll)
@@ -228,7 +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)
@@ -242,12 +245,8 @@ proc importModuleAs(c: PContext; n: PNode, realModule: PSym, importHidden, track
    # avoids modifying `realModule`, see D20201209T194412 for `import {.all.}`
    result = createModuleAliasImpl(realModule.name)
  if importHidden:
-    ensureMutable result
-    result.optionsImpl.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))
+    result.options.incl optImportHidden
+  c.unusedImports.add((result, n.info))
  c.importModuleMap[result.id] = realModule.id
  c.importModuleLookup.mgetOrPut(result.name.id, @[]).addUnique realModule.id

@@ -288,10 +287,10 @@ 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)
-    let realModule = c.graph.importModuleCallback(c.graph, c.module, f)
-    result = importModuleAs(c, n, realModule, transf.importHidden, trackUnusedImport)
+    realModule = c.graph.importModuleCallback(c.graph, c.module, f)
+    result = importModuleAs(c, n, realModule, transf.importHidden)
    popOptionEntry(c)

    #echo "set back to ", L
@@ -304,9 +303,9 @@ proc myImportModule(c: PContext, n: var PNode, importStmtResult: PNode): PSym =
      var prefix = ""
      if realModule.constraint != nil: prefix = realModule.constraint.strVal & "; "
      message(c.config, n.info, warnDeprecated, prefix & realModule.name.s & " is deprecated")
-    let moduleNameNorm = getModuleName(c.config, n).replace("\\", "/")
-    if belongsToStdlib(c.graph, result) and not startsWith(moduleNameNorm, stdPrefix) and
-        not startsWith(moduleNameNorm, "system/") and not startsWith(moduleNameNorm, "packages/"):
+    let moduleName = getModuleName(c.config, n)
+    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) =
@@ -335,7 +334,7 @@ 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)
@@ -372,7 +371,7 @@ 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:
@@ -387,7 +386,7 @@ 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
@@ -24,7 +24,7 @@ import std/[strtabs, tables, strutils, intsets]
 when defined(nimPreviewSlimSystem):
  import std/assertions

-from trees import exprStructuralEquivalent, getRoot, isCursor, whichPragma, getPotentialWrites
+from trees import exprStructuralEquivalent, getRoot, whichPragma

 type
  Con = object
@@ -69,14 +69,12 @@ proc hasDestructor(c: Con; t: PType): bool {.inline.} =
  result = ast.hasDestructor(t)
  when toDebug.len > 0:
    # for more effective debugging
-    if not result and c.graph.config.selectedGC in {gcArc, gcOrc, gcYrc, gcAtomicArc}:
+    if not result and c.graph.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
      assert(not containsGarbageCollectedRef(t))

-proc getTemp(c: var Con; s: var Scope; typ: PType; info: TLineInfo; needsInit: bool): PNode =
+proc getTemp(c: var Con; s: var Scope; typ: PType; info: TLineInfo): PNode =
  let sym = newSym(skTemp, getIdent(c.graph.cache, ":tmpD"), c.idgen, c.owner, info)
  sym.typ = typ
-  if not needsInit:
-    sym.incl sfNoInit
  s.vars.add(sym)
  result = newSymNode(sym)

@@ -102,7 +100,6 @@ when false:
 proc isLastReadImpl(n: PNode; c: var Con; scope: var Scope): bool =
  let root = parampatterns.exprRoot(n, allowCalls=false)
  if root == nil: return false
-  elif sfSingleUsedTemp in root.flags: return true

  var s = addr(scope)
  while s != nil:
@@ -165,25 +162,33 @@ proc isLastReadImpl(n: PNode; c: var Con; scope: var Scope): bool =
  else:
    result = false

-template hasDestructorOrAsgn(c: var Con, typ: PType): bool =
-  # bug #23354; an object type could have a non-trivial assignements when it is passed to a sink parameter
-  hasDestructor(c, typ) or (c.graph.config.selectedGC in {gcArc, gcOrc, gcYrc, gcAtomicArc} and
-        typ.kind == tyObject and not isTrivial(getAttachedOp(c.graph, typ, attachedAsgn)))
-
 proc isLastRead(n: PNode; c: var Con; s: var Scope): bool =
-  if not hasDestructorOrAsgn(c, n.typ): return true
+  # 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

-  result = isLastReadImpl(n, c, s)
+  let m = skipConvDfa(n)
+  result = (m.kind == nkSym and sfSingleUsedTemp in m.sym.flags) or
+      isLastReadImpl(n, c, s)

 proc isFirstWrite(n: PNode; c: var Con): bool =
  let m = skipConvDfa(n)
  result = nfFirstWrite in m.flags

-template isFullyUnpackedTuple(n: PNode): bool =
+proc isCursor(n: PNode): bool =
+  case n.kind
+  of nkSym:
+    sfCursor in n.sym.flags
+  of nkDotExpr:
+    isCursor(n[1])
+  of nkCheckedFieldExpr:
+    isCursor(n[0])
+  else:
+    false
+
+template isUnpackedTuple(n: PNode): bool =
  ## we move out all elements of unpacked tuples,
  ## hence unpacked tuples themselves don't need to be destroyed
  ## except it's already a cursor
-  ## restricted to `skTemp`, tuple temps where not every field is unpacked should not use `skTemp`
  (n.kind == nkSym and n.sym.kind == skTemp and
   n.sym.typ.kind == tyTuple and sfCursor notin n.sym.flags)

@@ -192,8 +197,7 @@ proc checkForErrorPragma(c: Con; t: PType; ri: PNode; opname: string; inferredFr
  if inferredFromCopy:
    m.add ", which is inferred from unavailable '=copy'"

-  if (opname == "=" or opname == "=copy" or opname == "=dup") and
-       ri != nil:
+  if (opname == "=" or opname == "=copy" or opname == "=dup") and ri != nil:
    m.add "; requires a copy because it's not the last read of '"
    m.add renderTree(ri)
    m.add '\''
@@ -233,18 +237,6 @@ proc genOp(c: var Con; t: PType; kind: TTypeAttachedOp; dest, ri: PNode): PNode
    let canon = c.graph.canonTypes.getOrDefault(h)
    if canon != nil:
      op = getAttachedOp(c.graph, canon, kind)
-  if op == nil or op.ast.isGenericRoutine:
-    # IC: injectDestructorCalls is demand-driven and runs HERE (cg), not in the
-    # `lower` stage, so a structural, env-agnostic op the lower stage never had
-    # reason to serialize — most often a closure PROC type's `=destroy`/`=sink`
-    # (which act on the `(ClP_0, ClE_0)` tuple, NOT the concrete env) — must be
-    # lifted on demand, exactly as the lazy path's cg does. This is safe now:
-    # closure-env identity resolves via `attachedOps[itemId]`/env-erased typeKey,
-    # env objects load complete, and atomicRefOp's type-erased path covers any
-    # still-incomplete env (so the lift never walks a nil field).
-    excl t.flagsImpl, tfCheckedForDestructor
-    createTypeBoundOps(c.graph, nil, t, dest.info, c.idgen)
-    op = getAttachedOp(c.graph, t, kind)
  if op == nil:
    #echo dest.typ.id
    globalError(c.graph.config, dest.info, "internal error: '" & AttachedOpToStr[kind] &
@@ -255,12 +247,7 @@ proc genOp(c: var Con; t: PType; kind: TTypeAttachedOp; dest, ri: PNode): PNode
  dbg:
    if kind == attachedDestructor:
      echo "destructor is ", op.id, " ", op.ast
-  if sfError in op.flags:
-    if ri != nil:
-      checkForErrorPragma(c, t, ri, AttachedOpToStr[kind])
-    else:
-      # uses the lineinfos of `dest` is `ri` is not available
-      checkForErrorPragma(c, t, dest, AttachedOpToStr[kind])
+  if sfError in op.flags: checkForErrorPragma(c, t, ri, AttachedOpToStr[kind])
  c.genOp(op, dest)

 proc genDestroy(c: var Con; dest: PNode): PNode =
@@ -288,7 +275,7 @@ proc deepAliases(dest, ri: PNode): bool =
    return aliases(dest, ri) != no

 proc genSink(c: var Con; s: var Scope; dest, ri: PNode; flags: set[MoveOrCopyFlag] = {}): PNode =
-  if (c.inLoopCond == 0 and (isFullyUnpackedTuple(dest) or IsDecl in flags or
+  if (c.inLoopCond == 0 and (isUnpackedTuple(dest) or IsDecl in flags or
      (isAnalysableFieldAccess(dest, c.owner) and isFirstWrite(dest, c)))) or
      isNoInit(dest) or IsReturn in flags:
    # optimize sink call into a bitwise memcopy
@@ -304,7 +291,7 @@ proc genSink(c: var Con; s: var Scope; dest, ri: PNode; flags: set[MoveOrCopyFla
      if deepAliases(dest, ri):
        # consider: x = x + y, it is wrong to destroy the destination first!
        # tmp to support self assignments
-        let tmp = c.getTemp(s, dest.typ, dest.info, needsInit = false)
+        let tmp = c.getTemp(s, dest.typ, dest.info)
        result = newTree(nkStmtList, newTree(nkFastAsgn, tmp, dest), newTree(nkFastAsgn, dest, ri),
                         c.genDestroy(tmp))
      else:
@@ -330,15 +317,14 @@ 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 in {gcOrc, gcYrc} and IsExplicitSink notin flags:
-    # add cyclic flag, but not to sink calls, which IsExplicitSink generates
+proc finishCopy(c: var Con; result, dest: PNode; isFromSink: bool) =
+  if c.graph.config.selectedGC == gcOrc:
    let t = dest.typ.skipTypes(tyUserTypeClasses + {tyGenericInst, tyAlias, tySink, tyDistinct})
    if cyclicType(c.graph, t):
      result.add boolLit(c.graph, result.info, isFromSink or isCriticalLink(dest))

 proc genMarkCyclic(c: var Con; result, dest: PNode) =
-  if c.graph.config.selectedGC in {gcOrc, gcYrc}:
+  if c.graph.config.selectedGC == gcOrc:
    let t = dest.typ.skipTypes({tyGenericInst, tyAlias, tySink, tyDistinct})
    if cyclicType(c.graph, t):
      if t.kind == tyRef:
@@ -373,7 +359,7 @@ proc genDiscriminantAsgn(c: var Con; s: var Scope; n: PNode): PNode =
  # but fields within active case branch might need destruction

  # tmp to support self assignments
-  let tmp = c.getTemp(s, n[1].typ, n.info, needsInit = false)
+  let tmp = c.getTemp(s, n[1].typ, n.info)

  result = newTree(nkStmtList)
  result.add newTree(nkFastAsgn, tmp, p(n[1], c, s, consumed))
@@ -413,7 +399,7 @@ 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 & ")")
@@ -423,20 +409,6 @@ proc genDefaultCall(t: PType; c: Con; info: TLineInfo): PNode =
  result.add(newSymNode(createMagic(c.graph, c.idgen, "default", mDefault)))
  result.typ = t

-proc stabilizeBracketIndex(n: PNode; c: var Con; body: var PNode): PNode =
-  ## Evaluate a side-effecting index once and return the stable access.
-  doAssert n.kind == nkBracketExpr and not isAtom(n[1])
-  let temp = newSym(skLet, getIdent(c.graph.cache, "bracketTmp"), c.idgen,
-                    c.owner, n[1].info)
-  temp.typ = n[1].typ
-  let tempAsNode = newSymNode(temp)
-  body.add newTree(nkLetSection, n[1].info,
-                   newTree(nkIdentDefs, tempAsNode,
-                           newNodeI(nkEmpty, tempAsNode.info), n[1]))
-  result = copyNode(n)
-  result.add n[0]
-  result.add tempAsNode
-
 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:
@@ -448,10 +420,6 @@ proc destructiveMoveVar(n: PNode; c: var Con; s: var Scope): PNode =
  else:
    result = newNodeIT(nkStmtListExpr, n.info, n.typ)

-    var n = n
-    if n.kind == nkBracketExpr and not isAtom(n[1]):
-      n = stabilizeBracketIndex(n, c, result)
-
    var temp = newSym(skLet, getIdent(c.graph.cache, "blitTmp"), c.idgen, c.owner, n.info)
    temp.typ = n.typ
    var v = newNodeI(nkLetSection, n.info)
@@ -477,50 +445,49 @@ proc isCapturedVar(n: PNode): bool =
  else: result = false

 proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
+  result = newNodeIT(nkStmtListExpr, n.info, n.typ)
  let nTyp = n.typ.skipTypes(tyUserTypeClasses)
-  if not hasDestructorOrAsgn(c, nTyp):
-    # Non-managed (plain-old-data) type: no ownership transfer is needed.
-    # Return the expression directly — no temp required.
-    if c.graph.config.selectedGC in {gcArc, gcOrc, gcYrc, gcAtomicArc}:
+  let tmp = c.getTemp(s, nTyp, n.info)
+  if hasDestructor(c, nTyp):
+    let typ = nTyp.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")
+      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)
+
+      let src = p(n, c, s, normal)
+      var newCall = newTreeIT(nkCall, src.info, src.typ,
+            newSymNode(op),
+            src)
+      c.finishCopy(newCall, n, isFromSink = true)
+      result.add newTreeI(nkFastAsgn,
+          src.info, tmp,
+          newCall
+      )
+    else:
+      result.add c.genWasMoved(tmp)
+      var m = c.genCopy(tmp, n, {})
+      m.add p(n, c, s, normal)
+      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:
+      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)
+    if c.inEnsureMove > 0:
+      localError(c.graph.config, n.info, errFailedMove,
+        ("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}:
      localError(c.graph.config, n.info, "cannot create an implicit openArray copy to be passed to a sink parameter")
-    return p(n, c, s, normal)
-  result = newNodeIT(nkStmtListExpr, n.info, n.typ)
-  let tmp = c.getTemp(s, nTyp, n.info, needsInit = false)
-  let typ = nTyp.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")
-    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)
-
-    let src = p(n, c, s, normal)
-    var newCall = newTreeIT(nkCall, src.info, src.typ,
-          newSymNode(op),
-          src)
-    c.finishCopy(newCall, n, {}, isFromSink = true)
-    result.add newTreeI(nkFastAsgn,
-        src.info, tmp,
-        newCall
-    )
-  else:
-    result.add c.genWasMoved(tmp)
-    var m = c.genCopy(tmp, n, {})
-    m.add p(n, c, s, normal)
-    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:
-    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)
-  if c.inEnsureMove > 0:
-    localError(c.graph.config, n.info, errFailedMove,
-      ("cannot move '$1', passing '$1' to a sink parameter introduces an implicit copy") % $n)
+    result.add newTree(nkAsgn, tmp, p(n, c, s, normal))
  # Since we know somebody will take over the produced copy, there is
  # no need to destroy it.
  result.add tmp
@@ -534,7 +501,7 @@ proc containsConstSeq(n: PNode): bool =
    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:
@@ -551,7 +518,7 @@ proc ensureDestruction(arg, orig: PNode; c: var Con; s: var Scope): PNode =
    # produce temp creation for (fn, env). But we need to move 'env'?
    # This was already done in the sink parameter handling logic.
    result = newNodeIT(nkStmtListExpr, arg.info, arg.typ)
-    let tmp = c.getTemp(s, arg.typ, arg.info, true)
+    let tmp = c.getTemp(s, arg.typ, arg.info)
    result.add c.genSink(s, tmp, arg, {IsDecl})
    result.add tmp
    s.final.add c.genDestroy(tmp)
@@ -591,7 +558,7 @@ proc cycleCheck(n: PNode; c: var Con) =
 proc pVarTopLevel(v: PNode; c: var Con; s: var Scope; res: PNode) =
  # move the variable declaration to the top of the frame:
  s.vars.add v.sym
-  if isFullyUnpackedTuple(v):
+  if isUnpackedTuple(v):
    if c.inLoop > 0:
      # unpacked tuple needs reset at every loop iteration
      res.add newTree(nkFastAsgn, v, genDefaultCall(v.typ, c, v.info))
@@ -630,7 +597,7 @@ template processScopeExpr(c: var Con; s: var Scope; ret: PNode, processCall: unt
  # There is a possibility to do this check: s.wasMoved.len > 0 or s.final.len > 0
  # later and use it to eliminate the temporary when theres no need for it, but its
  # tricky because you would have to intercept moveOrCopy at a certain point
-  let tmp = c.getTemp(s.parent[], ret.typ, ret.info, needsInit = true)
+  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}:
@@ -791,10 +758,10 @@ proc pRaiseStmt(n: PNode, c: var Con; s: var Scope): PNode =
      result = copyNode(n)
      result.add call
    else:
-      let tmp = c.getTemp(s, n[0].typ, n.info, needsInit = true)
+      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
@@ -821,23 +788,6 @@ proc hasCustomDestructor(c: Con, t: PType): bool =
    obj = skipTypes(obj.baseClass, abstractPtrs)
    result = result or isCustomDestructor(c, obj)

-const
-  exprBranchKinds = {nkStmtListExpr, nkBlockExpr, nkIfExpr, nkCaseStmt,
-                     nkTryStmt, nkPragmaBlock}
-
-proc distributeAsgn(asgnKind: TNodeKind; dest, ri: PNode; c: var Con; s: var Scope): PNode =
-  ## Distributes an assignment ``dest = ri`` into the leaf expressions of
-  ## ``ri`` when ``ri`` is an expression-based control flow construct. This
-  ## avoids creating pointless intermediate temporaries (bug #25850). The
-  ## descent is recursive so that nestings like ``block: ...; if c: a else: b``
-  ## assign directly to ``dest`` instead of going through a temp per branch.
-  if ri.kind in exprBranchKinds:
-    template process(child, s): untyped =
-      distributeAsgn(asgnKind, dest, child, c, s)
-    handleNestedTempl(ri, process, willProduceStmt = true)
-  else:
-    result = newTree(asgnKind, dest, p(ri, c, s, consumed))
-
 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}:
@@ -851,7 +801,15 @@ 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
@@ -871,9 +829,6 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
    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)
@@ -927,14 +882,19 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
      if mode == normal and (isRefConstr or hasCustomDestructor(c, t)):
        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 parameters = n[0].typ
      let L = if parameters != nil: parameters.signatureLen else: 0

      when false:
@@ -944,19 +904,13 @@ 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:
@@ -964,7 +918,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing

      if n[0].kind == nkSym and n[0].sym.magic in {mNew, mNewFinalize}:
        result[0] = copyTree(n[0])
-        if c.graph.config.selectedGC in {gcHooks, gcArc, gcAtomicArc, gcOrc, gcYrc}:
+        if c.graph.config.selectedGC in {gcHooks, gcArc, gcAtomicArc, gcOrc}:
          let destroyOld = c.genDestroy(result[1])
          result = newTree(nkStmtList, destroyOld, result)
      else:
@@ -984,9 +938,6 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
    of nkVarSection, nkLetSection:
      # transform; var x = y to  var x; x op y  where op is a move or copy
      result = newNodeI(nkStmtList, n.info)
-
-      let isInProc = c.owner.kind in {skProc, skFunc, skMethod, skIterator, skConverter}
-
      for it in n:
        var ri = it[^1]
        if it.kind == nkVarTuple and hasDestructor(c, ri.typ):
@@ -1002,15 +953,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
              s.locals.add v.sym
              pVarTopLevel(v, c, s, result)
            if ri.kind != nkEmpty:
-              let isGlobalPragma = v.kind == nkSym and
-                      {sfPure, sfGlobal} <= v.sym.flags and
-                      isInProc
-
-              if isGlobalPragma:
-                c.graph.procGlobals.add newTree(nkFastAsgn, v, ri)
-              else:
-                let value = moveOrCopy(v, ri, c, s, if v.kind == nkSym: {IsDecl} else: {})
-                result.add value
+              result.add moveOrCopy(v, ri, c, s, if v.kind == nkSym: {IsDecl} else: {})
            elif ri.kind == nkEmpty and c.inLoop > 0:
              let skipInit = v.kind == nkDotExpr and # Closure var
                             sfNoInit in v[1].sym.flags
@@ -1039,11 +982,6 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
        result = moveOrCopy(p(n[0], c, s, mode), n[1], c, s, flags)
      elif isDiscriminantField(n[0]):
        result = c.genDiscriminantAsgn(s, n)
-      elif n[1].kind in exprBranchKinds:
-        # Distribute the assignment into each branch to avoid
-        # creating pointless temporaries for expression-based control flow.
-        let dest = p(n[0], c, s, mode)
-        result = distributeAsgn(n.kind, dest, n[1], c, s)
      else:
        result = copyNode(n)
        result.add p(n[0], c, s, mode)
@@ -1137,11 +1075,6 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
        result[i] = n[i]
    of nkGotoState, nkState, nkAsmStmt:
      result = n
-    of nkReplayAction:
-      # A `.rod`/NIF replay record. It only ever appears in a NIF-loaded
-      # module's TOP-LEVEL statements (the loader prepends the `(replay ...)`
-      # entries there); cgen discards it, so pass it through untouched.
-      result = n
    else:
      result = nil
      internalError(c.graph.config, n.info, "cannot inject destructors to node kind: " & $n.kind)
@@ -1173,30 +1106,24 @@ proc sameLocation*(a, b: PNode): bool =
    else: false

 proc genFieldAccessSideEffects(c: var Con; s: var Scope; dest, ri: PNode; flags: set[MoveOrCopyFlag] = {}): PNode =
-  result = newNodeI(nkStmtList, ri.info)
-  let newAccess = stabilizeBracketIndex(ri, c, result)
-  let snk = c.genSink(s, dest, newAccess, flags)
-  result.add snk
-  result.add c.genWasMoved(newAccess)
+  # with side effects
+  var temp = newSym(skLet, getIdent(c.graph.cache, "bracketTmp"), c.idgen, c.owner, ri[1].info)
+  temp.typ = ri[1].typ
+  var v = newNodeI(nkLetSection, ri[1].info)
+  let tempAsNode = newSymNode(temp)

-proc ownsData(c: var Con; s: var Scope; orig: PNode; flags: set[MoveOrCopyFlag]): PNode =
-  var n = orig
-  while true:
-    case n.kind
-    of nkDotExpr, nkCheckedFieldExpr, nkBracketExpr:
-      n = n[0]
-    else:
-      break
-  if n.kind in nkCallKinds and n.typ != nil and hasDestructor(c, n.typ):
-    result = newNodeIT(nkStmtListExpr, orig.info, orig.typ)
-    let tmp = c.getTemp(s, n.typ, n.info, needsInit = true)
-    tmp.sym.flagsImpl.incl sfSingleUsedTemp
-    result.add newTree(nkFastAsgn, tmp, copyTree(n))
-    s.final.add c.genDestroy(tmp)
-    n[] = tmp[]
-    result.add copyTree(orig)
-  else:
-    result = nil
+  var vpart = newNodeI(nkIdentDefs, tempAsNode.info, 3)
+  vpart[0] = tempAsNode
+  vpart[1] = newNodeI(nkEmpty, tempAsNode.info)
+  vpart[2] = ri[1]
+  v.add(vpart)
+
+  var newAccess = copyNode(ri)
+  newAccess.add ri[0]
+  newAccess.add tempAsNode
+
+  var snk = c.genSink(s, dest, newAccess, flags)
+  result = newTree(nkStmtList, v, snk, c.genWasMoved(newAccess))

 proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopyFlag] = {}): PNode =
  var ri = ri
@@ -1224,7 +1151,7 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
    of nkCallKinds:
      result = c.genSink(s, dest, p(ri, c, s, consumed), flags)
    of nkBracketExpr:
-      if isFullyUnpackedTuple(ri[0]):
+      if isUnpackedTuple(ri[0]):
        # unpacking of tuple: take over the elements
        result = c.genSink(s, dest, p(ri, c, s, consumed), flags)
      elif isAnalysableFieldAccess(ri, c.owner) and isLastRead(ri, c, s):
@@ -1242,7 +1169,7 @@ 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):
@@ -1250,7 +1177,7 @@ 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:
@@ -1271,24 +1198,17 @@ 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)
    of nkRaiseStmt:
      result = pRaiseStmt(ri, c, s)
    else:
-      let isOwnsData = ownsData(c, s, ri2, flags)
-
-      if isOwnsData != nil:
-        result = moveOrCopy(dest, isOwnsData, c, s, flags)
-      elif isAnalysableFieldAccess(ri, c.owner) and isLastRead(ri, c, s) and
+      if isAnalysableFieldAccess(ri, c.owner) and isLastRead(ri, c, s) and
          canBeMoved(c, dest.typ):
        # Rule 3: `=sink`(x, z); wasMoved(z)
        let snk = c.genSink(s, dest, ri, flags)
@@ -1298,7 +1218,7 @@ 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) =
@@ -1327,55 +1247,6 @@ when false:
      for i in 0..<n.safeLen:
        injectDefaultCalls(n[i], c)

-proc replaceSinkParam(n: PNode, mapping: Table[int, PSym]): PNode =
-  case n.kind
-  of nkSym:
-    if n.sym.id in mapping:
-      result = newSymNode(mapping[n.sym.id])
-    else:
-      result = n
-  of nkVarSection, nkLetSection:
-    result = copyNode(n)
-    newSons(result, n.len)
-    for i in 0..<n.len:
-      result[i] = copyNode(n[i])
-      for j in 0..<n[i].len-1:
-        result[i].add n[i][j]
-      result[i].add replaceSinkParam(n[i][^1], mapping)
-  of {nkNone..nkNilLit}-{nkSym}, nkTypeSection, nkProcDef, nkConverterDef,
-      nkMethodDef, nkIteratorDef, nkMacroDef, nkTemplateDef, nkLambda, nkDo,
-      nkFuncDef, nkConstSection, nkConstDef, nkIncludeStmt, nkImportStmt,
-      nkExportStmt, nkPragma, nkCommentStmt, nkBreakState,
-      nkTypeOfExpr, nkMixinStmt, nkBindStmt:
-    result = n
-  else:
-    result = copyNode(n)
-    for i in 0..<n.len:
-      result.add replaceSinkParam(n[i], mapping)
-
-proc addSinkCopy(c: var Con; s: var Scope; sinkParams: seq[PSym]; n: PNode): PNode =
-  result = newNodeI(nkStmtList, n.info)
-  var mapping = initTable[int, PSym]()
-
-  var mutated = newSeq[PNode]()
-  getPotentialWrites(n, false, mutated)
-  var mutatedSet = initIntSet()
-  for m in mutated:
-    mutatedSet.incl m.sym.id
-  for param in sinkParams:
-    if param.id in mutatedSet:
-      let newSym = newSym(skTemp, getIdent(c.graph.cache, "sinkCopy"), c.idgen, param.owner, n.info)
-      newSym.flagsImpl.incl sfFromGeneric
-      newSym.typ = param.typ.elementType
-      mapping[param.id] = newSym
-      let v = newNodeI(nkVarSection, n.info)
-      v.addVar(newSymNode(newSym), newSymNode(param))
-      result.add v
-  if mapping.len > 0:
-    result.add replaceSinkParam(n, mapping)
-  else:
-    result = n
-
 proc injectDestructorCalls*(g: ModuleGraph; idgen: IdGenerator; owner: PSym; n: PNode): PNode =
  when toDebug.len > 0:
    shouldDebug = toDebug == owner.name.s or toDebug == "always"
@@ -1389,24 +1260,15 @@ proc injectDestructorCalls*(g: ModuleGraph; idgen: IdGenerator; owner: PSym; n:
  var scope = Scope(body: n)
  let body = p(n, c, scope, normal)

-  var sinkParams = newSeq[PSym]()
-
  if owner.kind in {skProc, skFunc, skMethod, skIterator, skConverter}:
    let params = owner.typ.n
    for i in 1..<params.len:
      let t = params[i].sym.typ
-      if isSinkTypeForParam(t):
-        let baseType = t.skipTypes({tySink})
-        if baseType.kind in {tyString, tySequence, tyArray, tyTuple, tyObject}:
-          sinkParams.add params[i].sym
-        if hasDestructor(c, baseType):
-          scope.final.add c.genDestroy(params[i])
+      if isSinkTypeForParam(t) and hasDestructor(c, t.skipTypes({tySink})):
+        scope.final.add c.genDestroy(params[i])
  #if optNimV2 in c.graph.config.globalOptions:
  #  injectDefaultCalls(n, c)
  result = optimize processScope(c, scope, body)
-  if sinkParams.len > 0:
-    result = addSinkCopy(c, scope, sinkParams, result)
-
  dbg:
    echo ">---------transformed-to--------->"
    echo renderTree(result, {renderIds})
--- a/compiler/inliner.nim
+++ b/compiler/inliner.nim
@@ -1,122 +0,0 @@
-
-proc copySymdef(n: PNode; locals: var Table[int, PSym]; idgen: IdGenerator; owner: PSym): PNode =
-  case n.kind
-  of nkEmpty..pred(nkSym), succ(nkSym)..nkNilLit:
-    result = n
-  of nkSym:
-    let oldSym = n.sym
-    let newSym = copySym(oldSym, idgen)
-    setOwner(newSym, owner)
-    locals[oldSym.id] = newSym
-    result = newSymNode(newSym, oldSym.info)
-  else:
-    result = shallowCopy(n)
-    for i in 0..<n.len:
-      result[i] = copySymdef(n[i], locals, idgen, owner)
-
-proc copyInlineProcBody(n: PNode; locals: var Table[int, PSym]; idgen: IdGenerator; owner: PSym): PNode =
-  case n.kind
-  of nkEmpty..pred(nkSym), succ(nkSym)..nkNilLit:
-    result = n
-  of nkSym:
-    let sym = locals.getOrDefault(n.sym.id)
-    if sym != nil:
-      result = newSymNode(sym, n.info)
-    else:
-      result = n
-  of nkLetSection, nkVarSection:
-    result = shallowCopy(n)
-    for i in 0..<n.len:
-      let it = n[i]
-      if it.kind == nkCommentStmt:
-        result[i] = it
-      elif it.kind in {nkIdentDefs, nkConstDef}:
-        result[i] = shallowCopy(it)
-        for j in 0..<it.len-2:
-          result[i][j] = copySymdef(it[j], locals, idgen, owner)
-        for j in it.len-2..<it.len:
-          result[i][j] = copyInlineProcBody(it[j], locals, idgen, owner)
-      else:
-        assert it.kind == nkVarTuple
-        result[i] = shallowCopy(it)
-        for j in 0..<it.len-2:
-          assert it[j].kind == nkSym
-          let oldSym = it[j].sym
-          let newSym = copySym(oldSym, idgen)
-          setOwner(newSym, owner)
-          locals[oldSym.id] = newSym
-          result[i][j] = newSymNode(newSym, oldSym.info)
-        for j in it.len-2..<it.len:
-          result[i][j] = copyInlineProcBody(it[j], locals, idgen, owner)
-
-  of nkForStmt, nkParForStmt:
-    result = shallowCopy(n)
-    for i in 0..<n.len-2:
-      assert n[i].kind == nkSym
-      let oldSym = n[i].sym
-      let newSym = copySym(oldSym, idgen)
-      setOwner(newSym, owner)
-      locals[oldSym.id] = newSym
-      result[i] = newSymNode(newSym, oldSym.info)
-    result[n.len-2] = copyInlineProcBody(n[n.len-2], locals, idgen, owner)
-    result[n.len-1] = copyInlineProcBody(n[n.len-1], locals, idgen, owner)
-  of routineDefs, nkTypeSection, nkTypeOfExpr, nkMixinStmt, nkBindStmt, nkConstSection:
-    result = n
-  else:
-    result = shallowCopy(n)
-    for i in 0..<n.len:
-      result[i] = copyInlineProcBody(n[i], locals, idgen, owner)
-
-proc copyParams(n: PNode; locals: var Table[int, PSym]; idgen: IdGenerator; owner: PSym): PNode =
-  result = shallowCopy(n)
-  result[0] = n[0] # return type
-  for i in 1..<n.len:
-    let it = n[i]
-    assert it.kind == nkIdentDefs
-    result[i] = shallowCopy(it)
-    for j in 0..<it.len-2:
-      assert it[j].kind == nkSym
-      let oldSym = it[j].sym
-      let newSym = copySym(oldSym, idgen)
-      setOwner(newSym, owner)
-      locals[oldSym.id] = newSym
-      result[i][j] = newSymNode(newSym, oldSym.info)
-      owner.typ.addParam newSym
-    for j in it.len-2..<it.len:
-      result[i][j] = copyInlineProcBody(it[j], locals, idgen, owner)
-
-proc copyInlineProc(prc: PSym; idgen: IdGenerator): PSym =
-  result = copySym(prc, idgen)
-  var locals = initTable[int, PSym]()
-
-  var a = shallowCopy(prc.ast)
-  if resultPos < prc.ast.len and prc.ast[resultPos].kind == nkSym:
-    let oldRes = prc.ast[resultPos].sym
-    let newRes = copySym(oldRes, idgen)
-    setOwner(newRes, result)
-    locals[oldRes.id] = newRes
-    a[resultPos] = newSymNode(newRes, oldRes.info)
-
-  result.typ = copyType(prc.typ, idgen, result)
-  result.typ.n = newNodeI(prc.typ.n.kind, prc.typ.n.info)
-  if prc.typ.n.len > 0:
-    result.typ.n.add copyNode(prc.typ.n[0])
-    for i in 1..<prc.typ.n.len:
-      let it = prc.typ.n[i]
-      assert it.kind == nkSym
-      let oldSym = it.sym
-      let newSym = copySym(oldSym, idgen)
-      setOwner(newSym, result)
-      locals[oldSym.id] = newSym
-      result.typ.addParam newSym
-
-  for i in 0..<prc.ast.len:
-    if i == paramsPos:
-      a[i] = copyTree(prc.ast[i])
-    elif i == resultPos and prc.ast[i].kind == nkSym:
-      discard "handled above"
-    else:
-      a[i] = copyInlineProcBody(prc.ast[i], locals, idgen, result)
-  result.ast = a
-
-  #echo "Produced: ", renderTree(result.ast, {renderIds})
--- a/compiler/installer.ini
+++ b/compiler/installer.ini
@@ -6,7 +6,7 @@ Name: "Nim"
 Version: "$version"
 Platforms: """
  windows: i386;amd64
-  linux: i386;hppa;ia64;alpha;amd64;powerpc64;arm;sparc;sparc64;s390x;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;loongarch64
  macosx: i386;amd64;powerpc64;arm64
  solaris: i386;amd64;sparc;sparc64
  freebsd: i386;amd64;powerpc64;arm;arm64;riscv64;sparc64;mips;mipsel;mips64;mips64el;powerpc;powerpc64el
@@ -80,7 +80,6 @@ Files: "lib"
 Files: "examples"
 Files: "dist/nimble"
 Files: "dist/checksums"
-Files: "dist/nimony"

 Files: "tests"

--- a/compiler/int128.nim
+++ b/compiler/int128.nim
@@ -340,6 +340,9 @@ proc `*`*(a: Int128, b: int32): Int128 =
  if b < 0:
    result = -result

+proc `*=`(a: var Int128, b: int32) =
+  a = a * b
+
 proc makeInt128(high, low: uint64): Int128 =
  result = Zero
  result.udata[0] = cast[uint32](low)
@@ -457,9 +460,7 @@ proc addInt128*(result: var string; value: Int128) =
    var i = initialSize
    var j = high(result)
    while i < j:
-      let tmp = result[i]
-      result[i] = result[j]
-      result[j] = tmp
+      swap(result[i], result[j])
      i += 1
      j -= 1

--- a/compiler/isolation_check.nim
+++ b/compiler/isolation_check.nim
@@ -166,7 +166,7 @@ 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/itemids.nim
+++ b/compiler/itemids.nim
@@ -1,98 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2026 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## `ItemId` is the identity of a symbol or type: a `(module, item)` pair.
-##
-## The fields are private on purpose: the module half reserves bit 30 as the
-## "backend minted" marker, so all construction and inspection has to go
-## through this module's API and the marker bit can never leak into module
-## indexing or arithmetic.
-##
-## Three id spaces coexist per module:
-## - Semantic-phase and NIF-loader ids: `itemId(module, item)` with `item > 0`.
-## - Backend-minted ids (IC codegen, `nim nifc`: transf labels and temps,
-##   lifted hooks): `backendItemId` sets `BackendModuleBit`, so these can
-##   never compare equal to a loader id even though both counters mint the
-##   same small `item` range in one process. They never cross a process
-##   boundary and must never be written to a NIF file.
-## - Derived env/tuple-field ids (`lowerings.addField`): the source local's
-##   id with `item` negated. `derivedFieldId` preserves the backend marker,
-##   keeping the derivation collision-free for both id spaces above.
-
-import std/hashes
-
-when defined(nimPreviewSlimSystem):
-  import std/assertions
-
-const
-  BackendModuleBit = 0x4000_0000'i32
-    # Bit 30 of the module field. Bit 31 stays clear so marked module values
-    # remain non-negative and cannot be mistaken for the special negative
-    # module ids like `PackageModuleId`.
-  PackageModuleId* = -3'i32
-
-type
-  ItemId* = object
-    moduleBits: int32
-    itemBits: int32
-
-proc itemId*(module, item: int32): ItemId {.inline.} =
-  assert module < 0 or (module and BackendModuleBit) == 0
-  ItemId(moduleBits: module, itemBits: item)
-
-proc backendItemId*(module, item: int32): ItemId {.inline.} =
-  ## An id minted during IC codegen; distinct from every `itemId` of the
-  ## same module so that the loader's stub counter and the backend's counter
-  ## cannot collide in id-keyed tables.
-  assert module >= 0 and (module and BackendModuleBit) == 0
-  ItemId(moduleBits: module or BackendModuleBit, itemBits: item)
-
-proc module*(x: ItemId): int32 {.inline.} =
-  if x.moduleBits >= 0: x.moduleBits and not BackendModuleBit
-  else: x.moduleBits
-
-proc item*(x: ItemId): int32 {.inline.} = x.itemBits
-
-proc isBackendMinted*(x: ItemId): bool {.inline.} =
-  x.moduleBits >= 0 and (x.moduleBits and BackendModuleBit) != 0
-
-proc derivedFieldId*(source: ItemId): ItemId {.inline.} =
-  ## The id of the env/tuple field that `lowerings.addField` derives for a
-  ## captured local: `item` negated, module bits (including the backend
-  ## marker) preserved.
-  ItemId(moduleBits: source.moduleBits, itemBits: -abs(source.itemBits))
-
-proc matchesDerivedFieldId*(field, source: ItemId): bool {.inline.} =
-  ## Does `field` carry the id `derivedFieldId` would derive for `source`?
-  ## `source` may itself already be the derived field id.
-  field.moduleBits == source.moduleBits and
-    field.itemBits == -abs(source.itemBits)
-
-proc `==`*(a, b: ItemId): bool {.inline.} =
-  # raw bit comparison: a backend-minted id never equals a loader id
-  a.itemBits == b.itemBits and a.moduleBits == b.moduleBits
-
-proc hash*(x: ItemId): Hash =
-  var h: Hash = hash(x.moduleBits)
-  h = h !& hash(x.itemBits)
-  result = !$h
-
-proc `$`*(x: ItemId): string =
-  result = "(module: " & $x.module & ", item: " & $x.itemBits
-  if x.isBackendMinted: result.add ", backend"
-  result.add ")"
-
-const
-  moduleShift = when defined(cpu32): 20 else: 24
-
-proc toId*(a: ItemId): int {.inline.} =
-  ## Packs an ItemId into a single int. Uses the raw module bits so the
-  ## backend marker keeps the two id spaces disjoint (bit 30 shifts to
-  ## bit 54; like the module/item split itself this needs a 64-bit int).
-  (a.moduleBits.int shl moduleShift) + a.itemBits.int
--- a/compiler/jsgen.nim
+++ b/compiler/jsgen.nim
@@ -33,8 +33,8 @@ import
  nversion, msgs, idents, types,
  ropes, wordrecg, renderer,
  cgmeth, lowerings, sighashes, modulegraphs, lineinfos,
-  transf, injectdestructors, sourcemap, astmsgs, pushpoppragmas,
-  mangleutils, varpartitions
+  transf, injectdestructors, sourcemap, astmsgs, backendpragmas,
+  mangleutils

 import pipelineutils

@@ -103,7 +103,7 @@ type
    prc: PSym
    globals, locals, body: Rope
    options: TOptions
-    optionsStack: seq[(TOptions, TNoteKinds)]
+    optionsStack: seq[TOptions]
    module: BModule
    g: PGlobals
    beforeRetNeeded: bool
@@ -148,6 +148,11 @@ proc newGlobals(): PGlobals =
        typeInfoGenerated: initIntSet()
        )

+proc initCompRes(): TCompRes =
+  result = TCompRes(address: "", res: "",
+    tmpLoc: "", typ: etyNone, kind: resNone
+  )
+
 proc rdLoc(a: TCompRes): Rope {.inline.} =
  if a.typ != etyBaseIndex:
    result = a.res
@@ -190,7 +195,7 @@ proc mapType(typ: PType): TJSTypeKind =
  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)
  of tyInt..tyInt64, tyUInt..tyUInt64, tyEnum, tyChar: result = etyInt
@@ -241,7 +246,7 @@ 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)
@@ -272,8 +277,7 @@ proc mangleName(m: BModule, s: PSym): Rope =
      else:
        result.add("_")
        result.add(rope(s.id))
-    ensureMutable s
-    s.locImpl.snippet = result
+    s.loc.r = result

 proc escapeJSString(s: string): string =
  result = newStringOfCap(s.len + s.len shr 2)
@@ -589,6 +593,15 @@ proc binaryUintExpr(p: PProc, n: PNode, r: var TCompRes, op: string,
      r.res = "(($1 $2 $3) $4)" % [x.rdLoc, rope op, y.rdLoc, trimmer]
  r.kind = resExpr

+template ternaryExpr(p: PProc, n: PNode, r: var TCompRes, magic, frmt: string) =
+  var x, y, z: TCompRes
+  useMagic(p, magic)
+  gen(p, n[1], x)
+  gen(p, n[2], y)
+  gen(p, n[3], z)
+  r.res = frmt % [x.rdLoc, y.rdLoc, z.rdLoc]
+  r.kind = resExpr
+
 template unaryExpr(p: PProc, n: PNode, r: var TCompRes, magic, frmt: string) =
  # $1 binds to n[1], if $2 is present it will be substituted to a tmp of $1
  useMagic(p, magic)
@@ -598,17 +611,6 @@ 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)
@@ -715,47 +717,44 @@ proc arithAux(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
  of mShrI:
    let typ = n[1].typ.skipTypes(abstractVarRange)
    if typ.kind == tyInt64 and optJsBigInt64 in p.config.globalOptions:
-      applyFormat("BigInt.asIntN(64, BigInt.asUintN(64, $1) >> (BigInt($2) & 63n))")
+      applyFormat("BigInt.asIntN(64, BigInt.asUintN(64, $1) >> BigInt($2))")
    elif typ.kind == tyUInt64 and optJsBigInt64 in p.config.globalOptions:
-      applyFormat("($1 >> (BigInt($2) & 63n))")
+      applyFormat("($1 >> BigInt($2))")
    else:
-      let bitmask = typ.size * 8 - 1
      if typ.kind in {tyInt..tyInt32}:
        let trimmerU = unsignedTrimmer(typ.size)
        let trimmerS = signedTrimmer(typ.size)
-        r.res = "((($1 $2) >>> ($3 & $5)) $4)" % [xLoc, trimmerU, yLoc, trimmerS, $bitmask]
+        r.res = "((($1 $2) >>> $3) $4)" % [xLoc, trimmerU, yLoc, trimmerS]
      else:
-        r.res = "($1 >>> ($2 & $3))" % [xLoc, yLoc, $bitmask]
+        applyFormat("($1 >>> $2)")
  of mShlI:
    let typ = n[1].typ.skipTypes(abstractVarRange)
    if typ.size == 8:
      if typ.kind == tyInt64 and optJsBigInt64 in p.config.globalOptions:
-        applyFormat("BigInt.asIntN(64, $1 << (BigInt($2) & 63n))")
+        applyFormat("BigInt.asIntN(64, $1 << BigInt($2))")
      elif typ.kind == tyUInt64 and optJsBigInt64 in p.config.globalOptions:
-        applyFormat("BigInt.asUintN(64, $1 << (BigInt($2) & 63n))")
+        applyFormat("BigInt.asUintN(64, $1 << BigInt($2))")
      else:
-        applyFormat("($1 * Math.pow(2, ($2 & 63)))")
+        applyFormat("($1 * Math.pow(2, $2))")
    else:
-      let bitmask = typ.size * 8 - 1
      if typ.kind in {tyUInt..tyUInt32}:
        let trimmer = unsignedTrimmer(typ.size)
-        r.res = "(($1 << ($2 & $4)) $3)" % [xLoc, yLoc, trimmer, $bitmask]
+        r.res = "(($1 << $2) $3)" % [xLoc, yLoc, trimmer]
      else:
        let trimmer = signedTrimmer(typ.size)
-        r.res = "(($1 << ($2 & $4)) $3)" % [xLoc, yLoc, trimmer, $bitmask]
+        r.res = "(($1 << $2) $3)" % [xLoc, yLoc, trimmer]
  of mAshrI:
    let typ = n[1].typ.skipTypes(abstractVarRange)
    if typ.size == 8:
      if optJsBigInt64 in p.config.globalOptions:
-        applyFormat("($1 >> (BigInt($2) & 63n))")
+        applyFormat("($1 >> BigInt($2))")
      else:
-        applyFormat("Math.floor($1 / Math.pow(2, ($2 & 63)))")
+        applyFormat("Math.floor($1 / Math.pow(2, $2))")
    else:
-      let bitmask = typ.size * 8 - 1
      if typ.kind in {tyUInt..tyUInt32}:
-        r.res = "($1 >>> ($2 & $3)))" % [xLoc, yLoc, $bitmask]
+        applyFormat("($1 >>> $2)")
      else:
-        r.res = "($1 >> ($2 & $3))" % [xLoc, yLoc, $bitmask]
+        applyFormat("($1 >> $2)")
  of mBitandI: bitwiseExpr("&")
  of mBitorI: bitwiseExpr("|")
  of mBitxorI: bitwiseExpr("^")
@@ -982,7 +981,7 @@ 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)])
@@ -992,9 +991,8 @@ 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:
-        ensureMutable excAlias.sym
-        excAlias.sym.locImpl.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, "}$n", [])
@@ -1100,19 +1098,14 @@ proc genCaseJS(p: PProc, n: PNode, r: var TCompRes) =
          lineF(p, "break;$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")
@@ -1126,8 +1119,7 @@ proc genBlock(p: PProc, n: PNode, r: var TCompRes) =
    # named block?
    if (n[0].kind != nkSym): internalError(p.config, n.info, "genBlock")
    var sym = n[0].sym
-    ensureMutable sym
-    sym.locImpl.k = locOther
+    sym.loc.k = locOther
    sym.position = idx+1
  let labl = p.unique
  lineF(p, "Label$1: {$n", [labl.rope])
@@ -1168,6 +1160,7 @@ proc genAsmOrEmitStmt(p: PProc, n: PNode; isAsmStmt = false) =
    of nkStrLit..nkTripleStrLit:
      p.body.add(it.strVal)
    of nkSym:
+      let v = it.sym
      # for backwards compatibility we don't deref syms here :-(
      if false:
        discard
@@ -1225,8 +1218,7 @@ proc generateHeader(p: PProc, prc: PSym): Rope =
      # to keep it simple
      let env = prc.ast[paramsPos].lastSon
      assert env.kind == nkSym, "env is missing"
-      ensureMutable env.sym
-      env.sym.locImpl.snippet = "this"
+      env.sym.loc.r = "this"

  for i in 1..<typ.n.len:
    assert(typ.n[i].kind == nkSym)
@@ -1240,6 +1232,17 @@ proc generateHeader(p: PProc, prc: PSym): Rope =
      result.add(name)
      result.add("_Idx")

+proc countJsParams(typ: PType): int =
+  result = 0
+  for i in 1..<typ.n.len:
+    assert(typ.n[i].kind == nkSym)
+    var param = typ.n[i].sym
+    if isCompileTimeOnly(param.typ): continue
+    if mapType(param.typ) == etyBaseIndex:
+      inc result, 2
+    else:
+      inc result
+
 const
  nodeKindsNeedNoCopy = {nkCharLit..nkInt64Lit, nkStrLit..nkTripleStrLit,
    nkFloatLit..nkFloat64Lit, nkPar, nkStringToCString,
@@ -1272,16 +1275,14 @@ proc genAsgnAux(p: PProc, x, y: PNode, noCopyNeeded: bool) =
    xtyp = etySeq
  case xtyp
  of etySeq:
-    if x.typ.kind in {tyVar, tyLent} or (needsNoCopy(p, y) and needsNoCopy(p, x)) or noCopyNeeded or
-        (x.kind == nkSym and sfCursor in x.sym.flags):
+    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")
      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 or
-        (x.kind == nkSym and sfCursor in x.sym.flags):
+    if x.typ.kind in {tyVar, tyLent, tyOpenArray, tyVarargs} or (needsNoCopy(p, y) and needsNoCopy(p, x)) or noCopyNeeded:
      lineF(p, "$1 = $2;$n", [a.rdLoc, b.rdLoc])
    else:
      useMagic(p, "nimCopy")
@@ -1354,16 +1355,13 @@ proc genFieldAddr(p: PProc, n: PNode, r: var TCompRes) =
  r.typ = etyBaseIndex
  let b = if n.kind == nkHiddenAddr: n[0] else: n
  gen(p, b[0], a)
-  if skipTypes(b[0].typ, abstractVarRange + tyTypeClasses).kind == tyTuple:
-    # ref #25227 about `+ tyTypeClasses`
+  if skipTypes(b[0].typ, abstractVarRange).kind == tyTuple:
    r.res = makeJSString("Field" & $getFieldPosition(p, b[1]))
  else:
    if b[1].kind != nkSym: internalError(p.config, b[1].info, "genFieldAddr")
    var f = b[1].sym
-    if f.loc.snippet == "": 
-      ensureMutable f
-      f.locImpl.snippet = mangleName(p.module, f)
-    r.res = makeJSString($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
@@ -1390,10 +1388,8 @@ 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 == "": 
-      ensureMutable f
-      f.locImpl.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

@@ -1413,15 +1409,11 @@ 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 == "": 
-    ensureMutable field
-    field.locImpl.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 == "": 
-    ensureMutable disc
-    disc.locImpl.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)
@@ -1438,32 +1430,18 @@ 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 isVarOpenArrayParam(n: PNode): bool =
-  ## True if `n` resolves to a `var openArray` parameter. The JS backend
-  ## represents such parameters as a `{base, off, len}` slice view so that
-  ## writes through a `toOpenArray` view reach the caller's storage (bug #15952).
-  var it = n
-  while true:
-    case it.kind
-    of nkHiddenDeref, nkDerefExpr, nkHiddenAddr, nkAddr: it = it[0]
-    of nkHiddenStdConv, nkConv, nkObjDownConv, nkObjUpConv: it = it[1]
-    else: break
-  result = it.kind == nkSym and it.sym.kind == skParam and
-    it.sym.typ != nil and it.sym.typ.kind == tyVar and
-    it.sym.typ.len > 0 and it.sym.typ[0].kind == tyOpenArray
-
 proc genArrayAddr(p: PProc, n: PNode, r: var TCompRes) =
  var
    a, b: TCompRes = default(TCompRes)
@@ -1472,19 +1450,6 @@ proc genArrayAddr(p: PProc, n: PNode, r: var TCompRes) =
  let m = if n.kind == nkHiddenAddr: n[0] else: n
  gen(p, m[0], a)
  gen(p, m[1], b)
-  if isVarOpenArrayParam(m[0]):
-    # `var openArray` param is a `{base, off, len}` view; index the base with
-    # the offset applied. `m[0]` is a plain param name, safe to reference
-    # repeatedly (no side effects, so no temp needed).
-    let pn = a.rdLoc
-    r.address = "($1).base" % [pn]
-    if optBoundsCheck in p.options:
-      useMagic(p, "chckIndx")
-      r.res = "($1).off + chckIndx($2, 0, ($1).len - 1)" % [pn, b.rdLoc]
-    else:
-      r.res = "($1).off + ($2)" % [pn, b.rdLoc]
-    r.kind = resExpr
-    return
  #internalAssert p.config, a.typ != etyBaseIndex and b.typ != etyBaseIndex
  let (x, tmp) = maybeMakeTemp(p, m[0], a)
  r.address = x
@@ -1541,13 +1506,13 @@ 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, skTemp, skForVar:
+  of skVar, skLet, skResult:
    r.kind = resExpr
    let jsType = mapType(p):
      if typ.isNil:
@@ -1558,15 +1523,15 @@ 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:
@@ -1604,12 +1569,15 @@ 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:
-      if n.kind in {nkAddr, nkHiddenAddr}:
-        # addr ( deref ( x )) --> x
-        gen(p, n[0][0], r)
-      else:
-        gen(p, n[0], r)
+    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:
@@ -1656,7 +1624,7 @@ 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
@@ -1667,7 +1635,7 @@ 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))
@@ -1678,29 +1646,29 @@ proc genSym(p: PProc, n: PNode, r: var TCompRes) =
      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
+    r.res = s.loc.r
  of skProc, skFunc, skConverter, skMethod, skIterator:
    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
@@ -1712,13 +1680,13 @@ 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) =
@@ -1753,47 +1721,8 @@ proc genArgNoParam(p: PProc, n: PNode, r: var TCompRes) =
  else:
    r.res.add(a.res)

-proc genVarOpenArrayArg(p: PProc, n: PNode, r: var TCompRes) =
-  ## Emit a `{base, off, len}` slice view for an argument to a `var openArray`
-  ## parameter (bug #15952). The view always aliases the base storage, so writes
-  ## through the callee's `openArray` reach the caller's array/seq/typed array.
-  var b, lo, hi, v: TCompRes = default(TCompRes)
-  # the argument reaches codegen as `addr(toOpenArray(x, lo, hi))` (possibly
-  # under conversions); unwrap to the actual `toOpenArray` call.
-  var sl = n
-  while true:
-    case sl.kind
-    of nkHiddenAddr, nkAddr, nkHiddenDeref, nkDerefExpr: sl = sl[0]
-    of nkHiddenStdConv, nkConv, nkObjDownConv, nkObjUpConv: sl = sl[1]
-    else: break
-  if sl.kind in nkCallKinds and getMagic(sl) == mSlice:
-    gen(p, sl[1], b)
-    gen(p, sl[2], lo)
-    gen(p, sl[3], hi)
-    if isVarOpenArrayParam(sl[1]):
-      # slicing a `var openArray` view: rebase onto the same underlying storage
-      r.res = "{base: ($1).base, off: ($1).off + $2, len: $3 - $2 + 1}" % [
-        b.rdLoc, lo.rdLoc, hi.rdLoc]
-    else:
-      r.res = "{base: $1, off: $2, len: $3 - $2 + 1}" % [
-        b.rdLoc, lo.rdLoc, hi.rdLoc]
-  elif isVarOpenArrayParam(sl):
-    # already a view from another `var openArray` param: forward it unchanged
-    gen(p, sl, b)
-    r.res = b.rdLoc
-  else:
-    # a whole array/seq/typed-array value: wrap with a zero offset
-    gen(p, n, v)
-    r.res = "{base: $1, off: 0, len: ($1).length}" % [v.rdLoc]
-  r.kind = resExpr
-
 proc genArg(p: PProc, n: PNode, param: PSym, r: var TCompRes; emitted: ptr int = nil) =
  var a: TCompRes = default(TCompRes)
-  if param.typ != nil and param.typ.kind == tyVar and param.typ[0].kind == tyOpenArray:
-    # `var openArray` params are passed as a `{base, off, len}` slice view.
-    genVarOpenArrayArg(p, n, a)
-    r.res.add(a.rdLoc)
-    return
  gen(p, n, a)
  if skipTypes(param.typ, abstractVar).kind in {tyOpenArray, tyVarargs} and
      a.typ == etyBaseIndex:
@@ -1803,13 +1732,6 @@ proc genArg(p: PProc, n: PNode, param: PSym, r: var TCompRes; emitted: ptr int =
    r.res.add(", ")
    r.res.add(a.res)
    if emitted != nil: inc emitted[]
-  elif skipTypes(param.typ, abstractVar).kind == tyOpenArray and
-      isVarOpenArrayParam(n):
-    # a `var openArray` view passed to a read-only `openArray` param: materialize
-    # a snapshot so the callee sees a plain array.
-    var w: TCompRes = default(TCompRes)
-    gen(p, n, w)
-    r.res.add("(($1).base).slice(($1).off, ($1).off + ($1).len)" % [w.rdLoc])
  elif n.typ.kind in {tyVar, tyPtr, tyRef, tyLent, tyOwned} and
      n.kind in nkCallKinds and mapType(param.typ) == etyBaseIndex:
    # this fixes bug #5608:
@@ -1844,6 +1766,12 @@ proc genArgs(p: PProc, n: PNode, r: var TCompRes; start=1) =
    inc emitted
    hasArgs = true
  r.res.add(")")
+  when false:
+    # XXX look into this:
+    let jsp = countJsParams(typ)
+    if emitted != jsp and tfVarargs notin typ.flags:
+      localError(p.config, n.info, "wrong number of parameters emitted; expected: " & $jsp &
+        " but got: " & $emitted)
  r.kind = resExpr

 proc genOtherArg(p: PProc; n: PNode; i: int; typ: PType;
@@ -1900,11 +1828,9 @@ 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 == "": 
-    ensureMutable f
-    f.locImpl.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)
@@ -2019,7 +1945,7 @@ 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)
@@ -2061,12 +1987,8 @@ proc createVar(p: PProc, typ: PType, indirect: bool): Rope =
    if indirect: result = "[$1]" % [result]
  of tyTuple:
    result = rope("{")
-    var first = true
    for i in 0..<t.len:
-      # Do not produce code for void types
-      if isEmptyType(t[i]): continue
-      if not first: result.add(", ")
-      first = false
+      if i > 0: result.add(", ")
      result.addf("Field$1: $2", [i.rope,
            createVar(p, t[i], false)])
    result.add("}")
@@ -2135,8 +2057,7 @@ 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) or
-          sfCursor in v.flags:
+      if v.typ.kind in {tyOpenArray, tyVarargs} or needsNoCopy(p, n):
        s = a.res
      else:
        useMagic(p, "nimCopy")
@@ -2146,28 +2067,28 @@ 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
@@ -2376,6 +2297,9 @@ proc genJSArrayConstr(p: PProc, n: PNode, r: var TCompRes) =
  r.res.add("]")

 proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
+  var
+    a: TCompRes
+    line, filen: Rope
  var op = n[0].sym.magic
  case op
  of mOr: genOr(p, n[1], n[2], r)
@@ -2396,8 +2320,8 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
      r.res = "if (null != $1) { if (null == $2) $2 = $3; else $2 += $3; }" %
        [b, lhs.rdLoc, tmp]
    else:
-      useMagic(p, "nimAddStrStr")
-      r.res = "nimAddStrStr($1, $2);" % [lhs.rdLoc, rhs.rdLoc]
+      let (a, tmp) = maybeMakeTemp(p, n[1], lhs)
+      r.res = "$1.push.apply($3, $2);" % [a, rhs.rdLoc, tmp]
    r.kind = resExpr
  of mAppendSeqElem:
    var x, y: TCompRes = default(TCompRes)
@@ -2444,21 +2368,13 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
      useMagic(p, "nimCopy")
      r.res = "nimCopy(null, $1, $2)" % [x.rdLoc, genTypeInfo(p, n.typ)]
  of mOpenArrayToSeq:
-    if isVarOpenArrayParam(n[1]):
-      var x: TCompRes = default(TCompRes)
-      gen(p, n[1], x)
-      r.res = "(($1).base).slice(($1).off, ($1).off + ($1).len)" % [x.rdLoc]
-      r.kind = resExpr
-    else:
-      genCall(p, n, r)
+    genCall(p, n, r)
  of mDestroy, mTrace: discard "ignore calls to the default destructor"
  of mOrd: genOrd(p, n, r)
  of mLengthStr, mLengthSeq, mLengthOpenArray, mLengthArray:
    var x: TCompRes = default(TCompRes)
    gen(p, n[1], x)
-    if isVarOpenArrayParam(n[1]):
-      r.res = "($1).len" % [x.rdLoc]
-    elif skipTypes(n[1].typ, abstractInst).kind == tyCstring:
+    if skipTypes(n[1].typ, abstractInst).kind == tyCstring:
      let (a, tmp) = maybeMakeTemp(p, n[1], x)
      r.res = "(($1) == null ? 0 : ($2).length)" % [a, tmp]
    else:
@@ -2467,9 +2383,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
  of mHigh:
    var x: TCompRes = default(TCompRes)
    gen(p, n[1], x)
-    if isVarOpenArrayParam(n[1]):
-      r.res = "($1).len - 1" % [x.rdLoc]
-    elif skipTypes(n[1].typ, abstractInst).kind == tyCstring:
+    if skipTypes(n[1].typ, abstractInst).kind == tyCstring:
      let (a, tmp) = maybeMakeTemp(p, n[1], x)
      r.res = "(($1) == null ? -1 : ($2).length - 1)" % [a, tmp]
    else:
@@ -2511,7 +2425,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
    binaryExpr(p, n, r, "mnewString",
      """if ($1.length < $2) { for (var i = $3.length; i < $4; ++i) $3.push(0); }
         else {$3.length = $4; }""")
-  of mSetLengthSeq, mSetLengthSeqUninit:
+  of mSetLengthSeq:
    var x, y: TCompRes = default(TCompRes)
    gen(p, n[1], x)
    gen(p, n[2], y)
@@ -2528,7 +2442,6 @@ 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:
@@ -2552,24 +2465,11 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
    genCall(p, n, r)
  of mSlice:
    # arr.slice([begin[, end]]): 'end' is exclusive
-    # Fixed homogeneous numeric arrays lower to JS typed arrays; `slice`
-    # copies, which silently breaks `var openArray` write-through (bug #15952).
-    # `subarray` returns a live shared-buffer view with the same
-    # exclusive-end signature, so use it there; keep `slice` for seqs/strings.
    var x, y, z: TCompRes = default(TCompRes)
    gen(p, n[1], x)
    gen(p, n[2], y)
    gen(p, n[3], z)
-    if isVarOpenArrayParam(n[1]):
-      # re-slicing a `var openArray` view: materialize from the view's base/offset
-      r.res = "(($1).base).slice(($1).off + $2, ($1).off + $3 + 1)" % [
-        x.rdLoc, y.rdLoc, z.rdLoc]
-    else:
-      let baseTy = skipTypes(n[1].typ, abstractVarRange + {tyLent})
-      if baseTy.kind == tyArray and arrayTypeForElemType(p.config, elemType(baseTy)).len > 0:
-        r.res = "($1.subarray($2, $3 + 1))" % [x.rdLoc, y.rdLoc, z.rdLoc]
-      else:
-        r.res = "($1.slice($2, $3 + 1))" % [x.rdLoc, y.rdLoc, z.rdLoc]
+    r.res = "($1.slice($2, $3 + 1))" % [x.rdLoc, y.rdLoc, z.rdLoc]
    r.kind = resExpr
  of mMove:
    genMove(p, n, r)
@@ -2655,6 +2555,7 @@ proc genObjConstr(p: PProc, n: PNode, r: var TCompRes) =
  r.kind = resExpr
  var initList : Rope = ""
  var fieldIDs = initIntSet()
+  let nTyp = n.typ.skipTypes(abstractInst)
  for i in 1..<n.len:
    if i > 1: initList.add(", ")
    var it = n[i]
@@ -2662,19 +2563,17 @@ 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 == "": 
-      ensureMutable f
-      f.locImpl.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]
@@ -2733,13 +2632,7 @@ 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]
@@ -2861,11 +2754,6 @@ proc genProc(oldProc: PProc, prc: PSym): Rope =
  var transformedBody = transformBody(p.module.graph, p.module.idgen, prc, {})
  if sfInjectDestructors in prc.flags:
    transformedBody = injectDestructorCalls(p.module.graph, p.module.idgen, prc, transformedBody)
-  else:
-    # JS has a GC, so the destructor pass is off; but the cursor (alias) analysis
-    # is independent of ownership and always memory-safe on a traced target.
-    # Running it lets last-use `var b = a` aliases skip the deep `nimCopy`.
-    computeCursors(prc, transformedBody, p.module.graph)

  p.nested: genStmt(p, transformedBody)

@@ -2925,9 +2813,9 @@ 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) =
@@ -2971,8 +2859,6 @@ proc genCast(p: PProc, n: PNode, r: var TCompRes) =
  elif dest.kind in tyFloat..tyFloat64:
    if src.kind in {tyInt64, tyUInt64} and optJsBigInt64 in p.config.globalOptions:
      r.res = "Number($1)" % [r.res]
-  elif dest.kind == tyChar and (fromInt or fromUint):
-    r.res = "($1 & 255)" % [r.res]
  elif (src.kind == tyPtr and mapType(p, src) == etyObject) and dest.kind == tyPointer:
    r.address = r.res
    r.res = "null"
@@ -3106,7 +2992,7 @@ 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))
@@ -3157,7 +3043,16 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
  of nkGotoState, nkState:
    globalError(p.config, n.info, "not implemented")
  of nkBreakState:
-    genBreakState(p, n[0], r)
+    var a: TCompRes = default(TCompRes)
+    if n[0].kind == nkClosure:
+      gen(p, n[0][1], a)
+      let sym = n[0][1].typ[0].n[0].sym
+      r.res = "(($1).$2 < 0)" % [rdLoc(a), mangleName(p.module, sym)]
+    else:
+      gen(p, n[0], a)
+      let sym = n[0].typ[0].n[0].sym
+      r.res = "((($1.ClE_0).$2) < 0)" % [rdLoc(a), mangleName(p.module, sym)]
+    r.kind = resExpr
  of nkPragmaBlock: gen(p, n.lastSon, r)
  of nkComesFrom:
    discard "XXX to implement for better stack traces"
--- a/compiler/jstypes.nim
+++ b/compiler/jstypes.nim
@@ -122,7 +122,7 @@ proc genEnumInfo(p: PProc, typ: PType, name: Rope) =
         [name, genTypeInfo(p, typ.baseClass)])

 proc genTypeInfo(p: PProc, typ: PType): Rope =
-  let t = typ.skipTypes({tyGenericInst, tyDistinct, tyAlias, tySink, tyOwned} + tyUserTypeClasses)
+  let t = typ.skipTypes({tyGenericInst, tyDistinct, tyAlias, tySink, tyOwned})
  result = "NTI$1" % [rope(t.id)]
  if containsOrIncl(p.g.typeInfoGenerated, t.id): return
  case t.kind
--- a/compiler/lambdalifting.nim
+++ b/compiler/lambdalifting.nim
@@ -126,6 +126,11 @@ const
  paramName* = ":envP"
  envName* = ":env"

+proc newCall(a: PSym, b: PNode): PNode =
+  result = newNodeI(nkCall, a.info)
+  result.add newSymNode(a)
+  result.add b
+
 proc createClosureIterStateType*(g: ModuleGraph; iter: PSym; idgen: IdGenerator): PType =
  var n = newNodeI(nkRange, iter.info)
  n.add newIntNode(nkIntLit, -1)
@@ -145,7 +150,6 @@ template isIterator*(owner: PSym): bool =

 proc createEnvObj(g: ModuleGraph; idgen: IdGenerator; owner: PSym; info: TLineInfo): PType =
  result = createObj(g, idgen, owner, info, final=false)
-  result.incl tfFinal
  if owner.isIterator:
    rawAddField(result, createStateField(g, owner, idgen))

@@ -156,24 +160,12 @@ proc getClosureIterResult*(g: ModuleGraph; iter: PSym; idgen: IdGenerator): PSym
    # XXX a bit hacky:
    result = newSym(skResult, getIdent(g.cache, ":result"), idgen, iter, iter.info, {})
    result.typ = iter.typ.returnType
-    incl(result.flagsImpl, sfUsed)
+    incl(result.flags, sfUsed)
    iter.ast.add newSymNode(result)

-proc closureParams(routine: PSym): PNode =
-  ## The formal parameters node lambda lifting reads and extends. In a
-  ## from-source compilation `routine.ast[paramsPos]` and `routine.typ.n` are the
-  ## very same node (see the `typ.n.len` based position math below). Under IC the
-  ## loaded proc AST omits the parameters (they are kept only in `typ.n`), so
-  ## restore the shared node here.
-  result = routine.ast[paramsPos]
-  if (result == nil or result.kind == nkEmpty) and routine.typ != nil and
-      routine.typ.n != nil and routine.ast.len > paramsPos:
-    result = routine.typ.n
-    routine.ast[paramsPos] = result
-
-proc addHiddenParam*(routine: PSym, param: PSym) =
+proc addHiddenParam(routine: PSym, param: PSym) =
  assert param.kind == skParam
-  var params = closureParams(routine)
+  var params = routine.ast[paramsPos]
  # -1 is correct here as param.position is 0 based but we have at position 0
  # some nkEffect node:
  param.position = routine.typ.n.len-1
@@ -183,9 +175,7 @@ proc addHiddenParam*(routine: PSym, param: PSym) =
  #echo "produced environment: ", param.id, " for ", routine.id

 proc getEnvParam*(routine: PSym): PSym =
-  if routine.ast.isNil: return nil
-  let params = closureParams(routine)
-  if params == nil or params.len == 0: return nil
+  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
@@ -208,7 +198,7 @@ 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:
@@ -224,10 +214,6 @@ proc newAsgnStmt(le, ri: PNode, info: TLineInfo): PNode =
  result[0] = le
  result[1] = ri

-proc markInjectDestructors(s: PSym) {.inline.} =
-  backendEnsureMutable s
-  s.flagsImpl.incl sfInjectDestructors
-
 proc makeClosure*(g: ModuleGraph; idgen: IdGenerator; prc: PSym; env: PNode; info: TLineInfo): PNode =
  result = newNodeIT(nkClosure, info, prc.typ)
  result.add(newSymNode(prc))
@@ -240,7 +226,7 @@ proc makeClosure*(g: ModuleGraph; idgen: IdGenerator; prc: PSym; env: PNode; inf
  #if isClosureIterator(result.typ):
  createTypeBoundOps(g, nil, result.typ, info, idgen)
  if tfHasAsgn in result.typ.flags or optSeqDestructors in g.config.globalOptions:
-    markInjectDestructors(prc)
+    prc.flags.incl sfInjectDestructors

 template liftingHarmful(conf: ConfigRef; owner: PSym): bool =
  ## lambda lifting can be harmful for JS-like code generators.
@@ -252,7 +238,7 @@ proc createTypeBoundOpsLL(g: ModuleGraph; refType: PType; info: TLineInfo; idgen
    createTypeBoundOps(g, nil, refType.elementType, info, idgen)
    createTypeBoundOps(g, nil, refType, info, idgen)
    if tfHasAsgn in refType.flags or optSeqDestructors in g.config.globalOptions:
-      markInjectDestructors(owner)
+      owner.flags.incl sfInjectDestructors

 proc genCreateEnv(env: PNode): PNode =
  var c = newNodeIT(nkObjConstr, env.info, env.typ)
@@ -283,6 +269,7 @@ proc liftIterSym*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PN
    addVar(v, env)
    result.add(v)
  # add 'new' statement:
+  #result.add newCall(getSysSym(g, n.info, "internalNew"), env)
  result.add genCreateEnv(env)
  createTypeBoundOpsLL(g, env.typ, n.info, idgen, owner)
  result.add makeClosure(g, idgen, iter, env, n.info)
@@ -296,32 +283,12 @@ 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])
-  unsealForTransform(owner.typ)
-  incl(owner.typ, tfCapturesEnv)
-  # A closure proc type that captures an env owns a REF to it: copying the closure
-  # value must incref the env and destroying it must decref. That is exactly what
-  # `tfHasAsgn` signals to `injectDestructorCalls` (so a closure assignment becomes
-  # `=copy`, not a raw field store).
-  #
-  # Set it HERE (closure-type creation) so the flag is DETERMINISTIC and serializes
-  # with the type — but ONLY under `nim ic`. The per-module `lower` stage is a
-  # separate process that lowers routines in index order; if a consumer (e.g.
-  # `workNimAsyncContinue`) was lowered before the closure type's ops were lifted,
-  # its env store emitted a RAW assign with no incref → freed env → async
-  # "yielded `nil`". A normal single-process `nim c` build does NOT need this —
-  # `createTypeBoundOps` sets the flag lazily, in lift order, before it matters
-  # (the old `liftdestructors ~1498` "XXX Breaks IC!" side effect) — and setting it
-  # eagerly there REGRESSES codegen: a `=destroy` hook gets generated against the
-  # bare `void(*)(void)` proc representation but is then called with closure structs
-  # (`eqdestroy__u2__stdZtypedthreads` type mismatch — broke megatest). So gate on
-  # `cmdNifC`; normal builds keep the lazy (devel) behavior.
-  if g.config.cmd == cmdNifC:
-    incl(owner.typ, tfHasAsgn)
+  incl(owner.typ.flags, tfCapturesEnv)
  if not isEnv:
    owner.typ.callConv = ccClosure

@@ -367,7 +334,7 @@ proc asOwnedRef(c: var DetectionPass; t: PType): PType =
  if optOwnedRefs in c.graph.config.globalOptions:
    assert t.kind == tyRef
    result = newType(tyOwned, c.idgen, t.owner)
-    result.incl tfHasOwned
+    result.flags.incl tfHasOwned
    result.rawAddSon t
  else:
    result = t
@@ -439,37 +406,19 @@ Consider:
 proc isTypeOf(n: PNode): bool =
  n.kind == nkSym and n.sym.magic in {mTypeOf, mType}

-proc isEnvTypeForRoutine(envTyp: PType; routine: PSym): bool =
-  ## True if `envTyp` is (maybe wrapped) env object type owned by `routine`, as
-  ## created by `getEnvTypeForOwner` / `createEnvObj`.
-  let obj = envTyp.skipTypes({tyOwned, tyRef, tyPtr})
-  result = obj.kind == tyObject and obj.owner.id == routine.id
-
 proc addClosureParam(c: var DetectionPass; fn: PSym; info: TLineInfo) =
  var cp = getEnvParam(fn)
  let owner = if fn.kind == skIterator: fn else: fn.skipGenericOwner
  let t = c.getEnvTypeForOwner(owner, info)
  if cp == nil:
    cp = newSym(skParam, getIdent(c.graph.cache, paramName), c.idgen, fn, fn.info)
-    incl(cp.flagsImpl, sfFromGeneric)
+    incl(cp.flags, sfFromGeneric)
    cp.typ = t
    addHiddenParam(fn, cp)
  elif cp.typ != t and fn.kind != skIterator:
-    # Nested `liftLambdas` uses a fresh `DetectionPass`, so `getEnvTypeForOwner`
-    # can allocate another PType for the same logical env; the hidden param from
-    # the inner pass is authoritative (bug #21242).
-    if isEnvTypeForRoutine(cp.typ, owner) and isEnvTypeForRoutine(t, owner):
-      c.ownerToType[owner.id] = cp.typ
-    else:
-      localError(c.graph.config, fn.info, "internal error: inconsistent environment type")
+    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:
@@ -488,7 +437,7 @@ 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:
@@ -667,7 +616,7 @@ proc rawClosureCreation(owner: PSym;
        if owner.kind != skMacro:
          createTypeBoundOps(d.graph, nil, fieldAccess.typ, env.info, d.idgen)
        if tfHasAsgn in fieldAccess.typ.flags or optSeqDestructors in d.graph.config.globalOptions:
-          markInjectDestructors(owner)
+          owner.flags.incl sfInjectDestructors

  let upField = lookupInRecord(env.typ.skipTypes({tyOwned, tyRef, tyPtr}).n, getIdent(d.graph.cache, upName))
  if upField != nil:
@@ -675,17 +624,6 @@ proc rawClosureCreation(owner: PSym;
    if up != nil and upField.typ.skipTypes({tyOwned, tyRef, tyPtr}) == up.typ.skipTypes({tyOwned, tyRef, tyPtr}):
      result.add(newAsgnStmt(rawIndirectAccess(env, upField, env.info),
                 up, env.info))
-      # That assignment stores a real `ref`, so `injectDestructorCalls` has to
-      # find the up-field type's ops — otherwise it stays a raw pointer store,
-      # the enclosing env's refcount is one too low, and at teardown the two
-      # envs' mutually recursive `=destroy`s each believe they hold the last
-      # reference and recurse until the stack is gone. Whole-program cgen never
-      # noticed: some LATER lifting pass creates this very ref type's ops, and it
-      # runs before any routine's destructor injection. The per-module backend
-      # injects a routine right after lifting it (the `lower` stage), long before
-      # the module's top level is transformed at all (that is `cg`).
-      if up.typ != nil and up.typ.kind == tyRef and up.typ.elementType != nil:
-        createTypeBoundOpsLL(d.graph, up.typ, env.info, d.idgen, owner)
    #elif oldenv != nil and oldenv.typ == upField.typ:
    #  result.add(newAsgnStmt(rawIndirectAccess(env, upField, env.info),
    #             oldenv, env.info))
@@ -704,27 +642,16 @@ 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)
-  incl(v.flagsImpl, sfShadowed)
+  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:
@@ -733,20 +660,14 @@ 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))
-      # See the identical call in `rawClosureCreation`: the up-field's ops must
-      # exist by the time this assignment is destructor-injected.
-      if u.typ != nil and u.typ.kind == tyRef and u.typ.elementType != nil:
-        createTypeBoundOpsLL(d.graph, u.typ, iter.info, d.idgen, owner)
    else:
      localError(d.graph.config, iter.info, "internal error: cannot create up reference for iter")
  result.add makeClosure(d.graph, d.idgen, iter.sym, vnode, iter.info)
@@ -778,7 +699,7 @@ 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)
@@ -1033,20 +954,6 @@ proc liftForLoop*(g: ModuleGraph; body: PNode; idgen: IdGenerator; owner: PSym):
      for i in 0..<op.len-1:
        result.add op[i]

-  elif op.kind != nkSym: # might have side effects
-    # bug #25046
-    # create a temp for the closure
-    # var :closureTemp
-    # :closureTemp = ...
-    let tempSym = newSym(skLet, getIdent(g.cache, ":closureTemp"), idgen, owner, body.info)
-    tempSym.typ = call[0].typ
-    let temp = newSymNode(tempSym)
-    var v = newNodeI(nkVarSection, body.info)
-    addVar(v, temp)
-    result.add(v)
-    result.add newAsgnStmt(temp, call[0], body.info)
-    call[0] = temp
-
  var loopBody = newNodeI(nkStmtList, body.info, 3)
  var whileLoop = newNodeI(nkWhileStmt, body.info, 2)
  whileLoop[0] = newIntTypeNode(1, getSysType(g, body.info, tyBool))
--- a/compiler/layeredtable.nim
+++ b/compiler/layeredtable.nim
@@ -1,101 +0,0 @@
-import ast, astalgo
-
-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)
-  #copyIdTable(result.topLayer, pt.topLayer)
-
-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.counter
-
-proc newTypeMapLayer*(pt: LayeredIdTable): LayeredIdTable =
-  result = LayeredIdTable(topLayer: initTypeMapping(), 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:
-    # Must read nextLayer into a temp before destroying pt:
-    # `pt = pt.nextLayer[]` would call eqcopy(&pt, &(*pt.nextLayer)) which
-    # decrements pt.nextLayer's rc (freeing it) before reading pt.nextLayer.nextLayer.
-    let tmp = pt.nextLayer[]
-    pt = tmp
-
-iterator pairs*(pt: LayeredIdTable): (ItemId, PType) =
-  var tm = pt
-  while true:
-    for (k, v) in idTablePairs(tm.topLayer):
-      yield (k, v)
-    if tm.nextLayer == nil:
-      break
-    tm.setToPreviousLayer
-
-proc lookupById*(typeMap: LayeredIdTable, key: ItemId): PType =
-  ## Looks up an ItemId directly, observing the same layer shadowing rules as
-  ## `lookup`. This form is useful when a binding key was previously captured.
-  result = nil
-  var tm = typeMap
-  while true:
-    result = getOrDefault(tm.topLayer, key)
-    if result != nil or tm.nextLayer == nil:
-      return
-    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.bindingId)
-
-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.bindingId)
-
-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.bindingId, value)
--- a/compiler/layouter.nim
+++ b/compiler/layouter.nim
@@ -451,13 +451,7 @@ proc emitTok*(em: var Emitter; L: Lexer; tok: Token) =
  elif tok.indent >= 0:
    var newlineKind = ltCrucialNewline
    if em.keepIndents > 0:
-      # Apply the requested --indent width to "don't touch" regions (if/block
-      # expressions) too: keep the relative offset from the enclosing block
-      # baseline, but rebase it onto indWidth. Otherwise a non-default
-      # --indent would leave these lines at the original column and inject
-      # invalid indentation (see #20078).
-      em.indentLevel = em.indentStack.high * em.indWidth +
-                       (tok.indent - em.indentStack[^1])
+      em.indentLevel = tok.indent
    elif (em.lastTok in (splitters + oprSet) and
        tok.tokType notin (closedPars - {tkBracketDotRi})):
      if tok.tokType in openPars and tok.indent > em.indentStack[^1]:
--- a/compiler/lexer.nim
+++ b/compiler/lexer.nim
@@ -316,28 +316,6 @@ proc getNumber(L: var Lexer, result: var Token) =
    L.bufpos = msgPos
    lexMessage(L, msgKind, msg % t.literal)

-  proc checkBitWidth(L: var Lexer, base: NumericalBase, tokType: TokType, 
-                     numDigits: int, startpos: int) =
-    # Check bit width for non-base-10 literals
-    # Warn if the digit count exceeds what can fit in the target type
-    let bitsPerDigit = case base
-      of base2: 1
-      of base8: 3
-      of base16: 4
-      else: raiseAssert "unreachable"
-    let bitWidth = case tokType
-      of tkInt8Lit, tkUInt8Lit: 8
-      of tkInt16Lit, tkUInt16Lit: 16
-      of tkInt32Lit, tkUInt32Lit: 32
-      of tkInt64Lit, tkUIntLit, tkIntLit, tkUInt64Lit: 64
-      else: raiseAssert "unreachable"
-    # Maximum digits = ceil(bitWidth / bitsPerDigit) = (bitWidth + bitsPerDigit - 1) div bitsPerDigit
-    let maxDigits = (bitWidth + bitsPerDigit - 1) div bitsPerDigit
-    if numDigits > maxDigits:
-      lexMessageLitNum(L,
-        "number has " & $numDigits & " digits but type only supports " &
-        $maxDigits & " digits: '$1'", startpos, warnLongLiterals)
-
  var
    xi: BiggestInt
    isBase10 = true
@@ -513,11 +491,6 @@ proc getNumber(L: var Lexer, result: var Token) =
          setNumber result.fNumber, (cast[ptr float64](addr(xi)))[]
        else: internalError(L.config, getLineInfo(L), "getNumber")

-        # Check bit width for non-base-10 literals
-        # Warn if the digit count exceeds what can fit in the target type
-        if result.base != base10 and result.tokType in {tkIntLit..tkUInt64Lit} and numDigits > 0:
-          checkBitWidth(L, result.base, result.tokType, numDigits, startpos)
-
        # Bounds checks. Non decimal literals are allowed to overflow the range of
        # the datatype as long as their pattern don't overflow _bitwise_, hence
        # below checks of signed sizes against uint*.high is deliberate:
@@ -735,11 +708,17 @@ proc getEscapedChar(L: var Lexer, tok: var Token) =
  else: lexMessage(L, errGenerated, "invalid character constant")

 proc handleCRLF(L: var Lexer, pos: int): int =
-  result =
-    case L.buf[pos]
-    of CR: nimlexbase.handleCR(L, pos)
-    of LF: nimlexbase.handleLF(L, pos)
-    else: pos
+  template registerLine =
+    let col = L.getColNumber(pos)
+
+  case L.buf[pos]
+  of CR:
+    registerLine()
+    result = nimlexbase.handleCR(L, pos)
+  of LF:
+    registerLine()
+    result = nimlexbase.handleLF(L, pos)
+  else: result = pos

 type
  StringMode = enum
@@ -839,8 +818,8 @@ proc getCharacter(L: var Lexer; tok: var Token) =

 const
  UnicodeOperatorStartChars = {'\226', '\194', '\195'}
-    # the allowed unicode characters ("∙ ∘ × ★ ☆ ⊗ ⊘ ⊙ ⊛ ⊠ ⊡ ∩ ∧ ⊓ ⟑ ⟇ ⩓ ⩔ ■ □
-    # ± ⊕ ⊖ ⊞ ⊟ ∪ ∨ ⊔") all start with one of these.
+    # the allowed unicode characters ("∙ ∘ × ★ ⊗ ⊘ ⊙ ⊛ ⊠ ⊡ ∩ ∧ ⊓ ± ⊕ ⊖ ⊞ ⊟ ∪ ∨ ⊔")
+    # all start with one of these.

 type
  UnicodeOprPred = enum
@@ -872,18 +851,7 @@ proc unicodeOprLen(buf: cstring; pos: int): (int8, UnicodeOprPred) =
      elif buf[pos+2] == '\159': result = 3.a # ⊟
      elif buf[pos+2] == '\160': result = 3.m # ⊠
      elif buf[pos+2] == '\161': result = 3.m # ⊡
-    elif buf[pos+1] == '\150':
-      if buf[pos+2] == '\160': result = 3.m # ■
-      elif buf[pos+2] == '\161': result = 3.m # □
-    elif buf[pos+1] == '\152':
-      if buf[pos+2] == '\133': result = 3.m # ★
-      elif buf[pos+2] == '\134': result = 3.m # ☆
-    elif buf[pos+1] == '\159':
-      if buf[pos+2] == '\135': result = 3.m # ⟇
-      elif buf[pos+2] == '\145': result = 3.m # ⟑
-    elif buf[pos+1] == '\169':
-      if buf[pos+2] == '\147': result = 3.m # ⩓
-      elif buf[pos+2] == '\148': result = 3.m # ⩔
+    elif buf[pos+1] == '\152' and buf[pos+2] == '\133': result = 3.m # ★
  of '\194':
    if buf[pos+1] == '\177': result = 2.a # ±
  of '\195':
@@ -928,7 +896,7 @@ proc getSymbol(L: var Lexer, tok: var Token) =
    tok.tokType = tkSymbol
  else:
    tok.tokType = TokType(tok.ident.id + ord(tkSymbol))
-    if suspicious and {optStyleHint, optStyleError, optStyleWarning} * L.config.globalOptions != {}:
+    if suspicious and {optStyleHint, optStyleError} * L.config.globalOptions != {}:
      lintReport(L.config, getLineInfo(L), tok.ident.s.normalize, tok.ident.s)
  L.bufpos = pos

@@ -1354,7 +1322,7 @@ proc rawGetTok*(L: var Lexer, tok: var Token) =
          lexMessage(L, errGenerated, "invalid token: no whitespace between number and identifier")
    of '-':
      if L.buf[L.bufpos+1] in {'0'..'9'} and
-          (L.bufpos == 0 or L.buf[L.bufpos-1] in UnaryMinusWhitelist):
+          (L.bufpos-1 == 0 or L.buf[L.bufpos-1] in UnaryMinusWhitelist):
        # x)-23 # binary minus
        # ,-23  # unary minus
        # \n-78 # unary minus? Yes.
--- a/compiler/liftdestructors.nim
+++ b/compiler/liftdestructors.nim
@@ -40,7 +40,7 @@ template asink*(t: PType): PSym = getAttachedOp(c.g, t, attachedSink)

 proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode)
 proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator): PSym
+              info: TLineInfo; idgen: IdGenerator; isDistinct = false): PSym

 proc createTypeBoundOps*(g: ModuleGraph; c: PContext; orig: PType; info: TLineInfo;
                         idgen: IdGenerator)
@@ -91,24 +91,14 @@ proc defaultOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    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 =
-  # These synthesized addresses are always passed to codegen procs that expect a
-  # genuine pointer (nimAsgnYrc, nimSinkYrc, destructors, ...). `addr(deref x)`
-  # collapses to `x` only when `x` is a real pointer; on the C++ backend a `var`
-  # parameter is a C++ reference, so we must keep the `nkHiddenAddr` to actually
-  # take its address (`&dest`) instead of passing the reference's value. Likewise
-  # `tfVarIsPtr` keeps the C++ backend from lowering the synthesized address back
-  # to a reference and dropping the `&` (e.g. a closure's `tyPointer` env). See
-  # #26026 CI (yrc + cpp).
-  if x.kind == nkHiddenDeref and c.g.config.backend != backendCpp:
+  if x.kind == nkHiddenDeref:
    checkSonsLen(x, 1, c.g.config)
    result = x[0]
  else:
-    let addrTyp = makeVarType(x.typ.owner, x.typ, c.idgen)
-    addrTyp.incl tfVarIsPtr
-    result = newNodeIT(nkHiddenAddr, x.info, addrTyp)
+    result = newNodeIT(nkHiddenAddr, x.info, makeVarType(x.typ.owner, x.typ, c.idgen))
    result.add x

 proc genWhileLoop(c: var TLiftCtx; i, dest: PNode): PNode =
@@ -158,7 +148,7 @@ proc destructorCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
  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

@@ -173,12 +163,12 @@ proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool,
    if c.filterDiscriminator != nil: return
    let f = n.sym
    let b = if c.kind == attachedTrace: y else: y.dotField(f)
-    if (sfCursor in f.flags and c.g.config.selectedGC in {gcArc, gcAtomicArc, gcOrc, gcYrc, gcHooks}) or
+    if (sfCursor in f.flags and c.g.config.selectedGC in {gcArc, gcAtomicArc, gcOrc, gcHooks}) or
        enforceDefaultOp:
      defaultOp(c, f.typ, body, x.dotField(f), b)
    else:
      if enforceWasMoved:
-        body.add genBuiltin(c, mWasMoved, "wasMoved", x.dotField(f))
+        body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x.dotField(f))
      fillBody(c, f.typ, body, x.dotField(f), b)
  of nkNilLit: discard
  of nkRecCase:
@@ -228,38 +218,17 @@ 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:
-    # destroys in reverse order #24719
-    if c.kind == attachedDestructor:
-      for i in countdown(n.len-1, 0):
-        fillBodyObj(c, n[i], body, x, y, enforceDefaultOp, enforceWasMoved)
-    else:
-      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, enforceWasMoved)
  else:
    illFormedAstLocal(n, c.g.config)

 proc fillBodyObjTImpl(c: var TLiftCtx; t: PType, body, x, y: PNode) =
-  template fillBase =
-    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)
-  template fillFields =
-    fillBodyObj(c, t.n, body, x, y, enforceDefaultOp = false)
-
-  if c.kind == attachedDestructor:
-    # destroys in reverse order #24719
-    fillFields()
-    fillBase()
-  else:
-    fillBase()
-    fillFields()
+  if t.baseClass != nil:
+    let obj = newNodeIT(nkHiddenSubConv, c.info, t.baseClass)
+    obj.add newNodeI(nkEmpty, c.info)
+    obj.add x
+    fillBody(c, skipTypes(t.baseClass, abstractPtrs), body, obj, 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)
@@ -294,7 +263,7 @@ proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
      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
-    incl(temp, sfFromGeneric)
+    incl(temp.flags, sfFromGeneric)
    var v = newNodeI(nkVarSection, c.info)
    let blob = newSymNode(temp)
    v.addVar(blob, x)
@@ -302,8 +271,7 @@ 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

@@ -390,10 +358,6 @@ proc requiresDestructor(c: TLiftCtx; t: PType): bool {.inline.} =
 proc instantiateGeneric(c: var TLiftCtx; op: PSym; t, typeInst: PType): PSym =
  if c.c != nil and typeInst != nil:
    result = c.c.instTypeBoundOp(c.c, op, typeInst, c.info, attachedAsgn, 1)
-  elif typeInst != nil and getAttachedOp(c.g, typeInst, c.kind) != nil:
-    # c.c == nil in lambdalifting
-    # hooks are already insted
-    result = getAttachedOp(c.g, typeInst, c.kind)
  else:
    localError(c.g.config, c.info,
      "cannot generate destructor for generic type: " & typeToString(t))
@@ -407,8 +371,7 @@ proc considerAsgnOrSink(c: var TLiftCtx; t: PType; body, x, y: PNode;
    if op != nil and op != c.fn and
        (sfOverridden in op.flags or destructorOverridden):
      if sfError in op.flags:
-        ensureMutable c.fn
-        incl c.fn.flagsImpl, sfError
+        incl c.fn.flags, sfError
      #else:
      #  markUsed(c.g.config, c.info, op, c.g.usageSym)
      onUse(c.info, op)
@@ -434,8 +397,7 @@ proc considerAsgnOrSink(c: var TLiftCtx; t: PType; body, x, y: PNode;
      if op == nil:
        op = produceSym(c.g, c.c, t, c.kind, c.info, c.idgen)
    if sfError in op.flags:
-      ensureMutable c.fn
-      incl c.fn.flagsImpl, sfError
+      incl c.fn.flags, sfError
    #else:
    #  markUsed(c.g.config, c.info, op, c.g.usageSym)
    onUse(c.info, op)
@@ -551,7 +513,7 @@ proc considerUserDefinedOp(c: var TLiftCtx; t: PType; body, x, y: PNode): bool =
 proc declareCounter(c: var TLiftCtx; body: PNode; first: BiggestInt): PNode =
  var temp = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), c.idgen, c.fn, c.info)
  temp.typ = getSysType(c.g, body.info, tyInt)
-  incl(temp.flagsImpl, sfFromGeneric)
+  incl(temp.flags, sfFromGeneric)

  var v = newNodeI(nkVarSection, c.info)
  result = newSymNode(temp)
@@ -561,29 +523,13 @@ proc declareCounter(c: var TLiftCtx; body: PNode; first: BiggestInt): PNode =
 proc declareTempOf(c: var TLiftCtx; body: PNode; value: PNode): PNode =
  var temp = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), c.idgen, c.fn, c.info)
  temp.typ = value.typ
-  incl(temp.flagsImpl, sfFromGeneric)
+  incl(temp.flags, sfFromGeneric)

  var v = newNodeI(nkVarSection, c.info)
  result = newSymNode(temp)
  v.addVar(result, value)
  body.add v

-proc considerInferDupFromCopy(c: var TLiftCtx; t: PType; body, x, y: PNode): bool =
-  ## For `=dup`, if no explicit hook exists, try to infer from `=copy` hook
-  ## to maintain backward compatibility. Returns true if inference was applied.
-  if c.kind == attachedDup:
-    var op2 = getAttachedOp(c.g, t, attachedAsgn)
-    if op2 != nil and sfOverridden in op2.flags:
-      #markUsed(c.g.config, c.info, op, c.g.usageSym)
-      onUse(c.info, op2)
-      body.add genBuiltin(c, mWasMoved, "wasMoved", x)
-      body.add newHookCall(c, op2, x, y)
-      result = true
-    else:
-      result = false
-  else:
-    result = false
-
 proc addIncStmt(c: var TLiftCtx; body, i: PNode) =
  let incCall = genBuiltin(c, mInc, "inc", i)
  incCall.add lowerings.newIntLit(c.g, c.info, 1)
@@ -596,12 +542,16 @@ proc newSeqCall(c: var TLiftCtx; x, y: PNode): PNode =
  lenCall.typ = getSysType(c.g, x.info, tyInt)
  result.add lenCall

-proc setLenSeqCall(c: var TLiftCtx; t: PType; x, y: PNode; noinit = false): PNode =
+proc setLenStrCall(c: var TLiftCtx; x, y: PNode): PNode =
+  let lenCall = genBuiltin(c, mLengthStr, "len", y)
+  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)
-  let name = if noinit: "setLenUninit" else: "setLen"
-  let magic = if noinit: mSetLengthSeqUninit else: mSetLengthSeq
-  var op = getSysMagic(c.g, x.info, name, magic)
+  var op = getSysMagic(c.g, x.info, "setLen", mSetLengthSeq)
  op = instantiateGeneric(c, op, t, t)
  result = newTree(nkCall, newSymNode(op, x.info), x, lenCall)

@@ -626,35 +576,11 @@ proc checkSelfAssignment(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  cond.typ = getSysType(c.g, c.info, tyBool)
  body.add genIf(c, cond, newTreeI(nkReturnStmt, c.info, newNodeI(nkEmpty, c.info)))

-proc genBulkCopySeq(c: var TLiftCtx; t: PType; body, x, y: PNode) =
-  ## Generates a call to nimCopySeqPayload for bulk memcpy of seq data.
-  let elemType = t.elementType
-  let sym = magicsys.getCompilerProc(c.g, "nimCopySeqPayload")
-  if sym == nil:
-    localError(c.g.config, c.info, "system module needs: nimCopySeqPayload")
-    return
-  var sizeOf = genBuiltin(c, mSizeOf, "sizeof", newNodeIT(nkType, c.info, elemType))
-  sizeOf.typ = getSysType(c.g, c.info, tyInt)
-  var alignOf = genBuiltin(c, mAlignOf, "alignof", newNodeIT(nkType, c.info, elemType))
-  alignOf.typ = getSysType(c.g, c.info, tyInt)
-  let call = newNodeI(nkCall, c.info)
-  call.add newSymNode(sym)
-  call.add newTreeIT(nkAddr, c.info, makePtrType(c.fn, x.typ, c.idgen), x)
-  call.add newTreeIT(nkAddr, c.info, makePtrType(c.fn, y.typ, c.idgen), y)
-  call.add sizeOf
-  call.add alignOf
-  call.typ = sym.typ.returnType
-  body.add call
-
 proc fillSeqOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  case c.kind
  of attachedDup:
-    let bulkCopy = supportsCopyMem(t.elementType)
-    body.add setLenSeqCall(c, t, x, y, noinit = bulkCopy)
-    if bulkCopy:
-      genBulkCopySeq(c, t, body, x, y)
-    else:
-      forallElements(c, t, body, x, y)
+    body.add setLenSeqCall(c, t, x, y)
+    forallElements(c, t, body, x, y)
  of attachedAsgn, attachedDeepCopy:
    # we generate:
    # if x.p == y.p:
@@ -663,14 +589,9 @@ proc fillSeqOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    # var i = 0
    # while i < y.len: dest[i] = y[i]; inc(i)
    # This is usually more efficient than a destroy/create pair.
-    # For trivially copyable types, use bulk copyMem instead of element loop.
    checkSelfAssignment(c, t, body, x, y)
-    let bulkCopy = supportsCopyMem(t.elementType)
-    body.add setLenSeqCall(c, t, x, y, noinit = bulkCopy)
-    if bulkCopy:
-      genBulkCopySeq(c, t, body, x, y)
-    else:
-      forallElements(c, t, body, x, y)
+    body.add setLenSeqCall(c, t, x, y)
+    forallElements(c, t, body, x, y)
  of attachedSink:
    let moveCall = genBuiltin(c, mMove, "move", x)
    moveCall.add y
@@ -685,7 +606,7 @@ 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)
@@ -715,11 +636,6 @@ proc useSeqOrStrOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      doAssert t.asink != nil
      body.add newHookCall(c, t.asink, x, y)
  of attachedDestructor:
-    when defined(icDbg):
-      if t.destructor == nil:
-        echo "MISSING destructor: ", typeToString(t), " kind=", t.kind,
-          " itemId=", t.itemId, " bindingId=", t.bindingId, " state=", t.state,
-          " owner=", (if t.owner != nil: t.owner.name.s else: "nil")
    doAssert t.destructor != nil
    body.add destructorCall(c, t.destructor, x)
  of attachedTrace:
@@ -728,7 +644,7 @@ 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)
@@ -741,23 +657,16 @@ proc fillStrOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  of attachedAsgn, attachedDeepCopy, attachedDup:
    body.add callCodegenProc(c.g, "nimAsgnStrV2", c.info, genAddr(c, x), y)
  of attachedSink:
-    if c.g.config.usesSso():
-      # SmallString: destroy old dst, then bit-copy src (no rc increment — this is a move).
-      # No .p aliasing check needed; rc-based destroy handles COW sharing correctly.
-      doAssert t.destructor != nil
-      body.add destructorCall(c, t.destructor, x)
-      body.add newAsgnStmt(x, y)
-    else:
-      let moveCall = genBuiltin(c, mMove, "move", x)
-      moveCall.add y
-      doAssert t.destructor != nil
-      moveCall.add destructorCall(c, t.destructor, x)
-      body.add moveCall
+    let moveCall = genBuiltin(c, mMove, "move", x)
+    moveCall.add y
+    doAssert t.destructor != nil
+    moveCall.add destructorCall(c, t.destructor, x)
+    body.add moveCall
  of attachedDestructor:
    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
@@ -784,70 +693,25 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    dest[] = source
    decRef tmp

-  For YRC the write barrier is more complicated still and must be:
-
-    let tmp = dest
-    # assignment must come first so that the collector sees the most-recent graph:
-    atomic: dest[] = source
-    # Then teach the cycle collector about the changes edge (these use locks, see yrc.nim):
-    incRef source
-    decRef tmp
-
-  This is implemented as a single runtime call (nimAsgnYrc / nimSinkYrc).
  ]#
  var actions = newNodeI(nkStmtList, c.info)
  let elemType = t.elementType

  createTypeBoundOps(c.g, c.c, elemType, c.info, c.idgen)
+  let isCyclic = c.g.config.selectedGC == gcOrc and types.canFormAcycle(c.g, elemType)

-  # YRC uses dedicated runtime procs for the entire write barrier -- but ONLY
-  # for refs that can actually form cycles. Routing an acyclic ref through
-  # `nimAsgnYrc` defeats the entire purpose of `.acyclic`: the barrier defers
-  # the dec into a stripe queue, `drainStripe` then hands the cell to
-  # `registerLocal`, and it enters the collector as a capture ROOT -- so a
-  # type annotated precisely to stay out of the cycle collector gets traced
-  # by it anyway. (The collector never reaches such a cell by TRAVERSAL: the
-  # attachedTrace hook below only emits `nimTraceRef` when `isCyclic`. The
-  # queued dec was the only way in.)
-  #
-  # Falling through instead gives acyclic refs the same prompt arc-style
-  # reclamation they get under --mm:arc/orc, which is also what lets a thread
-  # that avoids cycles at compile time avoid the collector entirely at run
-  # time. `canFormAcycle` is the same predicate ccgtypes.nim:1903 uses to set
-  # the descriptor's acyclic flag, so codegen and runtime cannot disagree.
-  if c.g.config.selectedGC == gcYrc and types.canFormAcycle(c.g, elemType):
-    let desc =
-      if isFinal(elemType):
-        let ti = genBuiltin(c, mGetTypeInfoV2, "getTypeInfoV2", newNodeIT(nkType, x.info, elemType))
-        ti.typ = getSysType(c.g, c.info, tyPointer)
-        ti
-      else:
-        newNodeIT(nkNilLit, c.info, getSysType(c.g, c.info, tyPointer))
-    case c.kind
-    of attachedAsgn, attachedDup:
-      body.add callCodegenProc(c.g, "nimAsgnYrc", c.info, genAddr(c, x), y, desc)
-      return
-    of attachedSink:
-      body.add callCodegenProc(c.g, "nimSinkYrc", c.info, genAddr(c, x), y, desc)
-      return
-    else: discard # fall through for destructor, trace, wasMoved
-
-  let isCyclic = c.g.config.selectedGC in {gcOrc, gcYrc} and types.canFormAcycle(c.g, elemType)
-
-  let isInheritableAcyclicRef = c.g.config.selectedGC in {gcOrc, gcYrc} and
+  let isInheritableAcyclicRef = c.g.config.selectedGC == gcOrc and
                      (not isPureObject(elemType)) and
                      tfAcyclic in skipTypes(elemType, abstractInst+{tyOwned}-{tyTypeDesc}).flags
  # dynamic Acyclic refs need to use dyn decRef

-  let useStatic = isFinal(elemType)
-
  let tmp =
    if isCyclic and c.kind in {attachedAsgn, attachedSink, attachedDup}:
      declareTempOf(c, body, x)
    else:
      x

-  if useStatic:
+  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)
@@ -858,7 +722,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =

  var cond: PNode
  if isCyclic:
-    if useStatic:
+    if isFinal(elemType):
      let typInfo = genBuiltin(c, mGetTypeInfoV2, "getTypeInfoV2", newNodeIT(nkType, x.info, elemType))
      typInfo.typ = getSysType(c.g, c.info, tyPointer)
      cond = callCodegenProc(c.g, "nimDecRefIsLastCyclicStatic", c.info, tmp, typInfo)
@@ -893,7 +757,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  of attachedDeepCopy: assert(false, "cannot happen")
  of attachedTrace:
    if isCyclic:
-      if useStatic:
+      if isFinal(elemType):
        let typInfo = genBuiltin(c, mGetTypeInfoV2, "getTypeInfoV2", newNodeIT(nkType, x.info, elemType))
        typInfo.typ = getSysType(c.g, c.info, tyPointer)
        body.add callCodegenProc(c.g, "nimTraceRef", c.info, genAddrOf(x, c.idgen), typInfo, y)
@@ -901,7 +765,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
        # 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)
@@ -918,26 +782,7 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  let xenv = genBuiltin(c, mAccessEnv, "accessEnv", x)
  xenv.typ = getSysType(c.g, c.info, tyPointer)

-  # Closures are (fnPtr, env) pairs. nimAsgnYrc/nimSinkYrc handle the env pointer
-  # (atomic store + buffered inc/dec). We also need newAsgnStmt to copy the fnPtr.
-  if c.g.config.selectedGC == gcYrc:
-    let nilDesc = newNodeIT(nkNilLit, c.info, getSysType(c.g, c.info, tyPointer))
-    let yenv = genBuiltin(c, mAccessEnv, "accessEnv", y)
-    yenv.typ = getSysType(c.g, c.info, tyPointer)
-    case c.kind
-    of attachedAsgn, attachedDup:
-      # nimAsgnYrc: save old env, atomic store new env, inc new env, dec old env
-      body.add callCodegenProc(c.g, "nimAsgnYrc", c.info, genAddr(c, xenv), yenv, nilDesc)
-      # Raw struct copy to also update the function pointer (env write is redundant but benign)
-      body.add newAsgnStmt(x, y)
-      return
-    of attachedSink:
-      body.add callCodegenProc(c.g, "nimSinkYrc", c.info, genAddr(c, xenv), yenv, nilDesc)
-      body.add newAsgnStmt(x, y)
-      return
-    else: discard # fall through for destructor, trace, wasMoved
-
-  let isCyclic = c.g.config.selectedGC in {gcOrc, gcYrc}
+  let isCyclic = c.g.config.selectedGC == gcOrc
  let tmp =
    if isCyclic and c.kind in {attachedAsgn, attachedSink, attachedDup}:
      declareTempOf(c, body, xenv)
@@ -970,6 +815,7 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      body.add genIf(c, cond, actions)
    else:
      body.add genIf(c, yenv, callCodegenProc(c.g, "nimIncRef", c.info, yenv))
+
      body.add genIf(c, cond, actions)
      body.add newAsgnStmt(x, y)
  of attachedDup:
@@ -986,7 +832,7 @@ 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
@@ -1014,7 +860,7 @@ 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)
@@ -1042,7 +888,7 @@ 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:
@@ -1054,7 +900,7 @@ proc closureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
    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, gcYrc}:
+      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)
    case c.kind
@@ -1082,7 +928,7 @@ 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)
@@ -1100,25 +946,16 @@ 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
  of tyNone, tyEmpty, tyVoid: discard
-  of tyUncheckedArray:
-    # An UncheckedArray has no known length, so it cannot be copied, moved or
-    # destroyed as a value: it only ever lives behind a pointer and its bytes
-    # are managed manually (element ops for seqs/strings go through the
-    # seq/string hooks, which know the length). Emitting `x = y` for it (as the
-    # pointer-like group below does) produces an assignment of an unsized array,
-    # which the C backend cannot lower (genAssignment: tyUncheckedArray). So all
-    # value hooks for it are no-ops.
-    discard
  of tyPointer, tySet, tyBool, tyChar, tyEnum, tyInt..tyUInt64, tyCstring,
-      tyPtr, tyVar, tyLent:
+      tyPtr, tyUncheckedArray, tyVar, tyLent:
    defaultOp(c, t, body, x, y)
  of tyRef:
-    if c.g.config.selectedGC in {gcArc, gcOrc, gcYrc, gcAtomicArc}:
+    if c.g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
      atomicRefOp(c, t, body, x, y)
    elif (optOwnedRefs in c.g.config.globalOptions and
        optRefCheck in c.g.config.options):
@@ -1127,7 +964,7 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
      defaultOp(c, t, body, x, y)
  of tyProc:
    if t.callConv == ccClosure:
-      if c.g.config.selectedGC in {gcArc, gcOrc, gcYrc, gcAtomicArc}:
+      if c.g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
        atomicClosureOp(c, t, body, x, y)
      else:
        closureOp(c, t, body, x, y)
@@ -1159,13 +996,9 @@ 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:
@@ -1182,18 +1015,23 @@ 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)
-      elif tfUnion in t.flags: # bug #25236
-        defaultOp(c, t, body, x, y)
      else:
-        if not considerInferDupFromCopy(c, t, body, x, y):
+        if c.kind == attachedDup:
+          var op2 = getAttachedOp(c.g, t, attachedAsgn)
+          if op2 != nil and sfOverridden in op2.flags:
+            #markUsed(c.g.config, c.info, op, c.g.usageSym)
+            onUse(c.info, op2)
+            body.add newHookCall(c, t.assignment, x, y)
+          else:
+            fillBodyObjT(c, t, body, x, y)
+        else:
          fillBodyObjT(c, t, body, x, y)
  of tyDistinct:
    if not considerUserDefinedOp(c, t, body, x, y):
-      if not considerInferDupFromCopy(c, t, body, x, y):
-        fillBody(c, t.elementType, body, x, y)
+      fillBody(c, t.elementType, body, x, y)
  of tyTuple:
    fillBodyTup(c, t, body, x, y)
  of tyVarargs, tyOpenArray:
@@ -1202,7 +1040,7 @@ 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:
@@ -1219,7 +1057,9 @@ proc produceSymDistinctType(g: ModuleGraph; c: PContext; typ: PType;
  assert typ.kind == tyDistinct
  let baseType = typ.elementType
  if getAttachedOp(g, baseType, kind) == nil:
-    discard produceSym(g, c, baseType, kind, info, idgen)
+    # TODO: fixme `isDistinct` is a fix for #23552; remove it after
+    # `-d:nimPreviewNonVarDestructor` becomes the default
+    discard produceSym(g, c, baseType, kind, info, idgen, isDistinct = true)
  result = getAttachedOp(g, baseType, kind)
  setAttachedOp(g, idgen.module, typ, kind, result)

@@ -1233,14 +1073,14 @@ proc symDupPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttache
  res.typ = typ
  src.typ = typ

-  result.typ = newType(tyProc, idgen, result)
+  result.typ = newType(tyProc, idgen, owner)
  result.typ.n = newNodeI(nkFormalParams, info)
  rawAddSon(result.typ, res.typ)
  result.typ.n.add newNodeI(nkEffectList, info)

  result.typ.addParam src

-  if g.config.selectedGC in {gcOrc, gcYrc} and
+  if g.config.selectedGC == gcOrc and
    cyclicType(g, typ.skipTypes(abstractInst)):
    let cycleParam = newSym(skParam, getIdent(g.cache, "cyclic"),
                            idgen, result, info)
@@ -1254,11 +1094,11 @@ proc symDupPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttache
  n[bodyPos] = newNodeI(nkStmtList, info)
  n[resultPos] = newSymNode(res)
  result.ast = n
-  incl result.flagsImpl, {sfFromGeneric, sfGeneratedOp}
-  setHookDisamb(g, result, AttachedOpToStr[kind], typ)
+  incl result.flags, sfFromGeneric
+  incl result.flags, sfGeneratedOp

 proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator; isDiscriminant = false): PSym =
+              info: TLineInfo; idgen: IdGenerator; isDiscriminant = false; isDistinct = false): PSym =
  if kind == attachedDup:
    return symDupPrototype(g, typ, owner, kind, info, idgen)

@@ -1268,8 +1108,8 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
  let src = newSym(skParam, getIdent(g.cache, if kind == attachedTrace: "env" else: "src"),
                   idgen, result, info)

-  if kind == attachedDestructor and g.config.selectedGC in {gcArc, gcOrc, gcYrc, gcAtomicArc} and
-     ((g.config.isDefined("nimPreviewNonVarDestructor") and not isDiscriminant) or (typ.kind in {tyRef, tyString, tySequence})):
+  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} and not isDistinct)):
    dest.typ = typ
  else:
    dest.typ = makeVarType(typ.owner, typ, idgen)
@@ -1279,13 +1119,12 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
  else:
    src.typ = typ

-  # the hook OWNS its signature, like any routine sem'd from source
-  result.typ = newProcType(info, idgen, result)
+  result.typ = newProcType(info, idgen, owner)
  result.typ.addParam dest
  if kind notin {attachedDestructor, attachedWasMoved}:
    result.typ.addParam src

-  if kind == attachedAsgn and g.config.selectedGC in {gcOrc, gcYrc} and
+  if kind == attachedAsgn and g.config.selectedGC == gcOrc and
      cyclicType(g, typ.skipTypes(abstractInst)):
    let cycleParam = newSym(skParam, getIdent(g.cache, "cyclic"),
                            idgen, result, info)
@@ -1298,15 +1137,11 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
  n[paramsPos] = result.typ.n
  n[bodyPos] = newNodeI(nkStmtList, info)
  result.ast = n
-  incl result.flagsImpl, sfFromGeneric
-  incl result.flagsImpl, sfGeneratedOp
+  incl result.flags, sfFromGeneric
+  incl result.flags, sfGeneratedOp
  if kind == attachedWasMoved:
-    incl result.flagsImpl, sfNoSideEffect
-    incl result.typ, tfNoSideEffect
-  if not isDiscriminant:
-    # discriminant destructors derive their body from the enclosing object
-    # AND the selected field; their key is set at the call site
-    setHookDisamb(g, result, AttachedOpToStr[kind], typ)
+    incl result.flags, sfNoSideEffect
+    incl result.typ.flags, tfNoSideEffect

 proc genTypeFieldCopy(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  let xx = genBuiltin(c, mAccessTypeField, "accessTypeField", x)
@@ -1316,23 +1151,13 @@ proc genTypeFieldCopy(c: var TLiftCtx; t: PType; body, x, y: PNode) =
  body.add newAsgnStmt(xx, yy)

 proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator): PSym =
+              info: TLineInfo; idgen: IdGenerator; isDistinct = false): PSym =
  if typ.kind == tyDistinct:
-    # For =dup, if the distinct type has a user-defined =copy, don't delegate
-    # to the base type. Instead fall through to the normal produceSym logic
-    # so that fillBody -> considerInferDupFromCopy can synthesize =dup from =copy.
-    if kind == attachedDup:
-      let copyOp = getAttachedOp(g, typ, attachedAsgn)
-      if copyOp != nil and sfOverridden in copyOp.flags:
-        discard "fall through to normal produceSym logic"
-      else:
-        return produceSymDistinctType(g, c, typ, kind, info, idgen)
-    else:
-      return produceSymDistinctType(g, c, typ, kind, info, idgen)
+    return produceSymDistinctType(g, c, typ, kind, info, idgen)

  result = getAttachedOp(g, typ, kind)
  if result == nil:
-    result = symPrototype(g, typ, typ.owner, kind, info, idgen)
+    result = symPrototype(g, typ, typ.owner, kind, info, idgen, isDistinct = isDistinct)

  var a = TLiftCtx(info: info, g: g, kind: kind, c: c, asgnForType: typ, idgen: idgen,
                   fn: result)
@@ -1349,48 +1174,33 @@ proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;

  if kind == attachedSink and destructorOverridden(g, typ):
    ## compiler can use a combination of `=destroy` and memCopy for sink op
-    ensureMutable dest
-    dest.flagsImpl.incl sfCursor
+    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 newAsgnStmt(d, src)
  else:
    var tk: TTypeKind
-    var skipped: PType = nil
-    if g.config.selectedGC in {gcArc, gcOrc, gcYrc, gcHooks, gcAtomicArc}:
-      skipped = skipTypes(typ, {tyOrdinal, tyRange, tyInferred, tyGenericInst, tyStatic, tyAlias, tySink})
-      tk = skipped.kind
+    if g.config.selectedGC in {gcArc, gcOrc, gcHooks, gcAtomicArc}:
+      tk = skipTypes(typ, {tyOrdinal, tyRange, tyInferred, tyGenericInst, tyStatic, tyAlias, tySink}).kind
    else:
      tk = tyNone # no special casing for strings and seqs
    case tk
    of tySequence:
-      let needsYrcLock = g.config.selectedGC == gcYrc and
-         kind in {attachedDestructor, attachedSink, attachedAsgn, attachedDeepCopy, attachedDup} and
-         types.canFormAcycle(g, skipped.elementType)
-      # YRC: topology-changing seq ops must hold the mutator (read) lock
-      if needsYrcLock:
-        result.ast[bodyPos].add callCodegenProc(g, "acquireMutatorLock", info)
      fillSeqOp(a, typ, result.ast[bodyPos], d, src)
-      if needsYrcLock:
-        result.ast[bodyPos].add callCodegenProc(g, "releaseMutatorLock", info)
    of tyString:
      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(skipped):
+      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:
-    ensureMutable result
-    incl result.flagsImpl, sfNeverRaises
+    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:
-    ensureMutable result
-    incl result.optionsImpl, optQuirky
  completePartialOp(g, idgen.module, typ, kind, result)


@@ -1399,7 +1209,6 @@ proc produceDestructorForDiscriminator*(g: ModuleGraph; typ: PType; field: PSym,
  assert(typ.skipTypes({tyAlias, tyGenericInst}).kind == tyObject)
  # discrimantor assignments needs pointers to destroy fields; alas, we cannot use non-var destructor here
  result = symPrototype(g, field.typ, typ.owner, attachedDestructor, info, idgen, isDiscriminant = true)
-  setHookDisamb(g, result, "=destroy¦" & field.name.s & "¦" & $field.position, typ)
  var a = TLiftCtx(info: info, g: g, kind: attachedDestructor, asgnForType: typ, idgen: idgen,
                   fn: result)
  a.asgnForType = typ
@@ -1416,9 +1225,7 @@ proc produceDestructorForDiscriminator*(g: ModuleGraph; typ: PType; field: PSym,
  result.ast[bodyPos].add v
  let placeHolder = newNodeIT(nkSym, info, getSysType(g, info, tyPointer))
  fillBody(a, typ, result.ast[bodyPos], d, placeHolder)
-  if not a.canRaise:
-    ensureMutable result
-    incl result.flagsImpl, sfNeverRaises
+  if not a.canRaise: incl result.flags, sfNeverRaises


 template liftTypeBoundOps*(c: PContext; typ: PType; info: TLineInfo) =
@@ -1453,7 +1260,7 @@ proc inst(g: ModuleGraph; c: PContext; t: PType; kind: TTypeAttachedOp; idgen: I
    else:
      localError(g.config, info, "unresolved generic parameter")

-proc isTrivial*(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;
@@ -1462,13 +1269,7 @@ proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInf
  ## to ensure we lift assignment, destructors and moves properly.
  ## The later 'injectdestructors' pass depends on it.
  if orig == nil or {tfCheckedForDestructor, tfHasMeta} * orig.flags != {}: return
-  # IC: review this solution again later
-  incl orig.flagsImpl, tfCheckedForDestructor
-  # for user defined generic destructors:
-  let origRoot = genericRoot(orig)
-  if origRoot != nil:
-    # IC: review this solution again later
-    incl origRoot.flagsImpl, tfGenericHasDestructor
+  incl orig.flags, tfCheckedForDestructor

  let skipped = orig.skipTypes({tyGenericInst, tyAlias, tySink})
  if isEmptyContainer(skipped) or skipped.kind == tyStatic: return
@@ -1488,13 +1289,13 @@ proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInf

  # we do not generate '=trace' procs if we
  # have the cycle detection disabled, saves code size.
-  let lastAttached = if g.config.selectedGC in {gcOrc, gcYrc}: attachedTrace
+  let lastAttached = if g.config.selectedGC == gcOrc: attachedTrace
                     else: attachedSink

  # bug #15122: We need to produce all prototypes before entering the
  # mind boggling recursion. Hacks like these imply we should rewrite
  # this module.
-  var generics = default(array[attachedWasMoved..attachedTrace, bool])
+  var generics: array[attachedWasMoved..attachedTrace, bool] = default(array[attachedWasMoved..attachedTrace, bool])
  for k in attachedWasMoved..lastAttached:
    generics[k] = getAttachedOp(g, canon, k) != nil
    if not generics[k]:
@@ -1510,9 +1311,8 @@ proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInf
    if canon != orig:
      setAttachedOp(g, idgen.module, orig, k, getAttachedOp(g, canon, k))

-  if not isTrivial(getAttachedOp(g, orig, attachedDestructor)):
-    #or not isTrivial(orig.assignment) or
-    # not isTrivial(orig.sink):
-    # IC: review this solution again later
-    orig.flagsImpl.incl tfHasAsgn
+  if not isTrival(getAttachedOp(g, orig, attachedDestructor)):
+    #or not isTrival(orig.assignment) or
+    # not isTrival(orig.sink):
+    orig.flags.incl tfHasAsgn
    # ^ XXX Breaks IC!
--- a/compiler/lineinfos.nim
+++ b/compiler/lineinfos.nim
@@ -92,15 +92,10 @@ type
    warnStmtListLambda = "StmtListLambda",
    warnBareExcept = "BareExcept",
    warnImplicitDefaultValue = "ImplicitDefaultValue",
-    warnIgnoredSymbolInjection = "IgnoredSymbolInjection",
-    warnStdPrefix = "StdPrefix",
-    warnUnknownNotes = "UnknownNotes",
-    warnLongLiterals = "LongLiterals",
+    warnGenericsIgnoredInjection = "GenericsIgnoredInjection",
+    warnStdPrefix = "StdPrefix"
    warnUser = "User",
    warnGlobalVarConstructorTemporary = "GlobalVarConstructorTemporary",
-    warnImplicitRangeConversion = "ImplicitRangeConversion",
-    warnSystemRangeConversion = "SystemRangeConversion",
-    warnInvalidCmpOp = "InvalidCmpOp",
    # hints
    hintSuccess = "Success", hintSuccessX = "SuccessX",
    hintCC = "CC",
@@ -114,9 +109,9 @@ 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] = [
@@ -203,15 +198,10 @@ const
    warnStmtListLambda: "statement list expression assumed to be anonymous proc; this is deprecated, use `do (): ...` or `proc () = ...` instead",
    warnBareExcept: "$1",
    warnImplicitDefaultValue: "$1",
-    warnIgnoredSymbolInjection: "$1",
+    warnGenericsIgnoredInjection: "$1",
    warnStdPrefix: "$1 needs the 'std' prefix",
-    warnUnknownNotes: "$1",
-    warnLongLiterals: "$1",
    warnUser: "$1",
    warnGlobalVarConstructorTemporary: "global variable '$1' initialization requires a temporary variable",
-    warnImplicitRangeConversion: "implicit range conversion $1",
-    warnSystemRangeConversion: "implicit range conversion $1",
-    warnInvalidCmpOp: "$1",
    hintSuccess: "operation successful: $#",
    # keep in sync with `testament.isSuccess`
    hintSuccessX: "$build\n$loc lines; ${sec}s; $mem; proj: $project; out: $output",
@@ -245,9 +235,9 @@ 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
@@ -266,9 +256,9 @@ type

 proc computeNotesVerbosity(): array[0..3, TNoteKinds] =
  result = default(array[0..3, TNoteKinds])
-  result[3] = {low(TNoteKind)..high(TNoteKind)} - {warnObservableStores, warnResultUsed, warnAnyEnumConv, warnBareExcept, warnStdPrefix, warnSystemRangeConversion}
+  result[3] = {low(TNoteKind)..high(TNoteKind)} - {warnObservableStores, warnResultUsed, warnAnyEnumConv, warnBareExcept, warnStdPrefix}
  result[2] = result[3] - {hintStackTrace, hintExtendedContext, hintDeclaredLoc, hintProcessingStmt}
-  result[1] = result[2] - {warnImplicitRangeConversion, warnProveField, warnProveIndex,
+  result[1] = result[2] - {warnProveField, warnProveIndex,
    warnGcUnsafe, hintPath, hintDependency, hintCodeBegin, hintCodeEnd,
    hintSource, hintGlobalVar, hintGCStats, hintMsgOrigin, hintPerformance}
  result[0] = result[1] - {hintSuccessX, hintSuccess, hintConf,
@@ -278,13 +268,8 @@ 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
-  FileInfoKind* = enum
-    fikSource,      ## A real source file path
-    fikNifModule    ## A NIF module suffix (not a real path)
-
  TFileInfo* = object
    fullPath*: AbsoluteFile    # This is a canonical full filesystem path
    projPath*: RelativeFile    # This is relative to the project's root
@@ -303,7 +288,6 @@ type
                               # for 'nimsuggest'
    hash*: string              # the checksum of the file
    dirty*: bool               # for 'nimpretty' like tooling
-    kind*: FileInfoKind        # distinguishes real files from NIF suffixes
    when defined(nimpretty):
      fullContent*: string
  FileIndex* = distinct int32
--- 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
@@ -95,9 +95,9 @@ proc nep1CheckDefImpl(conf: ConfigRef; info: TLineInfo; s: PSym; k: TSymKind) =
 template styleCheckDef*(ctx: PContext; info: TLineInfo; sym: PSym; k: TSymKind) =
  ## Check symbol definitions adhere to NEP1 style rules.
  if optStyleCheck in ctx.config.options and # ignore if styleChecks are off
-     {optStyleHint, optStyleError, optStyleWarning} * ctx.config.globalOptions != {} and # check only if hint/error/warning is enabled
+     {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
@@ -136,9 +136,9 @@ proc styleCheckUseImpl(conf: ConfigRef; info: TLineInfo; s: PSym) =

 template styleCheckUse*(ctx: PContext; info: TLineInfo; sym: PSym) =
  ## Check symbol uses match their definition's style.
-  if {optStyleHint, optStyleError, optStyleWarning} * ctx.config.globalOptions != {} and # ignore if styleChecks are off
+  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
@@ -152,7 +152,7 @@ proc checkPragmaUseImpl(conf: ConfigRef; info: TLineInfo; w: TSpecialWord; pragm
 template checkPragmaUse*(ctx: PContext; info: TLineInfo; w: TSpecialWord; pragmaName: string, sym: PSym) =
  ## Check builtin pragma uses match their definition's style.
  ## Note: This only applies to builtin pragmas, not user pragmas.
-  if {optStyleHint, optStyleError, optStyleWarning} * ctx.config.globalOptions != {} and # ignore if styleChecks are off
+  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)
@@ -163,7 +116,7 @@ proc llReadFromStdin(s: PLLStream, buf: pointer, bufLen: int): int =
  inc(s.lineOffset)
  result = min(bufLen, s.s.len - s.rd)
  if result > 0:
-    copyMem(buf, readRawData(s.s, s.rd), result)
+    copyMem(buf, addr(s.s[s.rd]), result)
    inc(s.rd, result)

 proc llStreamRead*(s: PLLStream, buf: pointer, bufLen: int): int =
@@ -173,7 +126,7 @@ proc llStreamRead*(s: PLLStream, buf: pointer, bufLen: int): int =
  of llsString:
    result = min(bufLen, s.s.len - s.rd)
    if result > 0:
-      copyMem(buf, readRawData(s.s, s.rd), result)
+      copyMem(buf, addr(s.s[0 + s.rd]), result)
      inc(s.rd, result)
  of llsFile:
    result = readBuffer(s.f, buf, bufLen)
--- 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:
@@ -75,13 +75,10 @@ proc addUniqueSym*(scope: PScope, s: PSym): PSym =
 proc openScope*(c: PContext): PScope {.discardable.} =
  result = PScope(parent: c.currentScope,
                  symbols: initStrTable(),
-                  depthLevel: c.scopeDepth + 1,
-                  optionStackLen: c.optionStack.len)
+                  depthLevel: c.scopeDepth + 1)
  c.currentScope = result

 proc rawCloseScope*(c: PContext) =
-  if c.currentScope.optionStackLen >= 1:
-    c.optionStack.setLen(c.currentScope.optionStackLen)
  c.currentScope = c.currentScope.parent

 proc closeScope*(c: PContext) =
@@ -222,14 +219,7 @@ 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)
@@ -239,12 +229,14 @@ proc searchScopes*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSym] =
        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):
@@ -258,7 +250,11 @@ proc selectFromScopesElseAll*(c: PContext, s: PIdent, filter: TSymKinds): seq[PS
        candidate = nextIdentIter(ti, scope.symbols)

  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 cmpScopes*(ctx: PContext, s: PSym): int =
  # Do not return a negative number
@@ -311,7 +307,7 @@ 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.flagsImpl, sfDiscardable)
+  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)
@@ -378,9 +374,6 @@ proc wrongRedefinition*(c: PContext; info: TLineInfo, s: string;
                        conflictsWith: TLineInfo, note = errGenerated) =
  ## Emit a redefinition error if in non-interactive mode
  if c.config.cmd != cmdInteractive:
-    when defined(icDbgRefc):
-      echo "[icRedef] ", s
-      echo getStackTrace()
    localError(c.config, info, note,
      "redefinition of '$1'; previous declaration here: $2" %
      [s, c.config $ conflictsWith])
@@ -391,7 +384,7 @@ proc addDeclAt*(c: PContext; scope: PScope, sym: PSym, info: TLineInfo) =
  if sym.name.id == ord(wUnderscore): return
  let conflict = scope.addUniqueSym(sym)
  if conflict != nil:
-    if sym.kind == skModule and conflict.kind == skModule and not c.config.isDefined("nimPreviewDuplicateModuleError"):
+    if sym.kind == skModule and conflict.kind == skModule:
      # e.g.: import foo; import foo
      # xxx we could refine this by issuing a different hint for the case
      # where a duplicate import happens inside an include.
@@ -415,6 +408,8 @@ proc addDecl*(c: PContext, sym: PSym) {.inline.} =
 proc addPrelimDecl*(c: PContext, sym: PSym) =
  discard c.currentScope.addUniqueSym(sym)

+from ic / ic import addHidden
+
 proc addInterfaceDeclAux(c: PContext, sym: PSym) =
  ## adds symbol to the module for either private or public access.
  if sfExported in sym.flags:
@@ -423,6 +418,8 @@ proc addInterfaceDeclAux(c: PContext, sym: PSym) =
    else: internalError(c.config, sym.info, "addInterfaceDeclAux")
  elif sym.kind in ExportableSymKinds and c.module != nil and isTopLevelInsideDeclaration(c, sym):
    strTableAdd(semtabAll(c.graph, c.module), sym)
+    if c.config.symbolFiles != disabledSf:
+      addHidden(c.encoder, c.packedRepr, sym)

 proc addInterfaceDeclAt*(c: PContext, scope: PScope, sym: PSym) =
  ## adds a symbol on the scope and the interface if appropriate
@@ -462,15 +459,6 @@ proc openShadowScope*(c: PContext) =
                          symbols: initStrTable(),
                          depthLevel: c.scopeDepth)

-proc rememberShadowDefs*(c: PContext) =
-  ## bug #25693: a template/macro operand's local definitions are sem-checked in
-  ## a shadow scope that is then discarded. Record those definitions so that a
-  ## later re-emission (e.g. a captured `typed` fragment expanded more than once)
-  ## can be detected as a redefinition rather than silently miscompiled.
-  for s in c.currentScope.symbols:
-    if s.kind in {skVar, skLet, skForVar} and {sfGenSym, sfWasGenSym} * s.flags == {}:
-      c.shadowDiscardedDefs.incl s.id
-
 proc closeShadowScope*(c: PContext) =
  ## closes the shadow scope, but doesn't merge any of the symbols
  ## Does not check for unused symbols or missing forward decls since a macro
@@ -573,33 +561,23 @@ proc errorUseQualifier*(c: PContext; info: TLineInfo; s: PSym) =
  var amb: bool = false
  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
@@ -652,10 +630,9 @@ type

 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):
+proc lookUpCandidates*(c: PContext, ident: PIdent, filter: set[TSymKind]): seq[PSym] =
+  result = searchInScopesFilterBy(c, ident, filter)
+  if result.len == 0:
    result.add allPureEnumFields(c, ident)

 proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
@@ -688,33 +665,24 @@ proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
    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 = false
            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)
      elif n[1].kind == nkSym:
@@ -733,10 +701,6 @@ 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
@@ -82,7 +82,7 @@ proc lowerTupleUnpacking*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: P
    var temp = newSym(skTemp, getIdent(g.cache, genPrefix), idgen,
                  owner, value.info, g.config.options)
    temp.typ = skipTypes(value.typ, abstractInst)
-    incl(temp.flagsImpl, sfFromGeneric)
+    incl(temp.flags, sfFromGeneric)
    tempAsNode = newSymNode(temp)

  var v = newNodeI(nkVarSection, value.info)
@@ -103,7 +103,7 @@ proc evalOnce*(g: ModuleGraph; value: PNode; idgen: IdGenerator; owner: PSym): P
  var temp = newSym(skTemp, getIdent(g.cache, genPrefix), idgen,
                    owner, value.info, g.config.options)
  temp.typ = skipTypes(value.typ, abstractInst)
-  incl(temp.flagsImpl, sfFromGeneric)
+  incl(temp.flags, sfFromGeneric)

  var v = newNodeI(nkLetSection, value.info)
  let tempAsNode = newSymNode(temp)
@@ -127,8 +127,8 @@ proc lowerSwap*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PNod
  # note: cannot use 'skTemp' here cause we really need the copy for the VM :-(
  var temp = newSym(skVar, getIdent(g.cache, genPrefix), idgen, owner, n.info, owner.options)
  temp.typ = n[1].typ
-  incl(temp.flagsImpl, sfFromGeneric)
-  incl(temp.flagsImpl, sfGenSym)
+  incl(temp.flags, sfFromGeneric)
+  incl(temp.flags, sfGenSym)

  var v = newNodeI(nkVarSection, n.info)
  let tempAsNode = newSymNode(temp)
@@ -147,13 +147,13 @@ proc createObj*(g: ModuleGraph; idgen: IdGenerator; owner: PSym, info: TLineInfo
  result = newType(tyObject, idgen, owner)
  if final:
    rawAddSon(result, nil)
-    incl result, tfFinal
+    incl result.flags, tfFinal
  else:
    rawAddSon(result, getCompilerProc(g, "RootObj").typ)
  result.n = newNodeI(nkRecList, info)
  let s = newSym(skType, getIdent(g.cache, "Env_" & toFilename(g.config, info) & "_" & $owner.name.s),
                  idgen, owner, info, owner.options)
-  incl s.flagsImpl, sfAnon
+  incl s.flags, sfAnon
  s.typ = result
  result.sym = s

@@ -207,70 +207,15 @@ proc lookupInRecord(n: PNode, id: ItemId): PSym =
        if result != nil: return
      else: discard
  of nkSym:
-    if matchesDerivedFieldId(n.sym.itemId, id): result = n.sym
-  else: discard
-
-proc lookupCapturedField(n: PNode, s: PSym): PSym =
-  ## Find an env field that `addField` would have produced for the captured
-  ## local `s`. Used as a fallback when the derived-itemId match fails because
-  ## `s` is a macro-generated gensym whose process-local id diverges from the
-  ## loaded env field's (see `addField`). `addField` always names a field
-  ## `s.name & $field.position`, so that pair uniquely identifies the field for a
-  ## local of this name without relying on the (unstable) item id.
-  result = nil
-  case n.kind
-  of nkRecList:
-    for i in 0..<n.len:
-      result = lookupCapturedField(n[i], s)
-      if result != nil: return
-  of nkRecCase:
-    if n[0].kind != nkSym: return
-    result = lookupCapturedField(n[0], s)
-    if result != nil: return
-    for i in 1..<n.len:
-      case n[i].kind
-      of nkOfBranch, nkElse:
-        result = lookupCapturedField(lastSon(n[i]), s)
-        if result != nil: return
-      else: discard
-  of nkSym:
-    if n.sym.kind == skField and n.sym.name.s == s.name.s & $n.sym.position:
-      result = n.sym
+    if n.sym.itemId.module == id.module and n.sym.itemId.item == -abs(id.item): result = n.sym
  else: discard

 proc addField*(obj: PType; s: PSym; cache: IdentCache; idgen: IdGenerator): PSym =
-  # Idempotent w.r.t. the captured symbol (mirrors `addUniqueField`): re-lifting
-  # a LOADED routine re-derives its transformed body (never serialized under IC)
-  # and re-captures the same locals, but the env object loaded from the NIF
-  # already carries their fields. Re-adding would duplicate the field and, worse,
-  # mutate a Sealed loaded type via `propagateToOwner` (the `t.state != Sealed`
-  # crash). Return the existing field instead.
-  let existing = lookupInRecord(obj.n, s.itemId)
-  if existing != nil:
-    return existing
-  # Re-lifting a LOADED routine during a VM transform (its transformed body is
-  # re-derived per process, never serialized) re-captures the same locals, but
-  # for a macro-generated gensym (e.g. libp2p `p2pProtocolBackendImpl`'s
-  # `msgVar`) its process-local id diverges from the one baked into the loaded
-  # env field, so the id match above misses. Reuse the existing same-named field
-  # rather than appending a divergent duplicate, which keeps the re-derived
-  # closure consistent (else a stale `:env` access reaches `cannotEval`).
-  # Confined to a loaded (Sealed) env: in a freshly built env ids are consistent,
-  # and two distinct same-named captures legitimately get distinct fields there.
-  if obj.state == Sealed:
-    let byName = lookupCapturedField(obj.n, s)
-    if byName != nil:
-      return byName
-  # Genuinely new field. Under IC the env may be a loaded Sealed type whose
-  # transform-time mutation is process-local (the body is discarded after the
-  # macro runs), so downgrade it to mutable instead of crashing on
-  # `t.state != Sealed` (mirrors `markAsClosure`).
-  unsealForTransform(obj)
  # because of 'gensym' support, we have to mangle the name with its ID.
  # This is hacky but the clean solution is much more complex than it looks.
  var field = newSym(skField, getIdent(cache, s.name.s & $obj.n.len),
                     idgen, s.owner, s.info, s.options)
-  field.itemId = derivedFieldId(s.itemId)
+  field.itemId = ItemId(module: s.itemId.module, item: -s.itemId.item)
  let t = skipIntLit(s.typ, idgen)
  field.typ = t
  if s.kind in {skLet, skVar, skField, skForVar}:
@@ -290,7 +235,7 @@ proc addUniqueField*(obj: PType; s: PSym; cache: IdentCache; idgen: IdGenerator)
  if result == nil:
    var field = newSym(skField, getIdent(cache, s.name.s & $obj.n.len), idgen,
                       s.owner, s.info, s.options)
-    field.itemId = derivedFieldId(s.itemId)
+    field.itemId = ItemId(module: s.itemId.module, item: -s.itemId.item)
    let t = skipIntLit(s.typ, idgen)
    field.typ = t
    assert t.kind != tyTyped
@@ -361,16 +306,6 @@ proc getFieldFromObj*(t: PType; v: PSym): PSym =
    assert t.kind == tyObject
    result = lookupInRecord(t.n, v.itemId)
    if result != nil: break
-    # A LOADED (Sealed) env object carries fields baked by the producer process;
-    # re-lifting a NIF-loaded routine in a consumer (e.g. a macro VM-evaluating an
-    # imported `p2pProtocolBackendImpl`) re-captures the same local under a
-    # divergent process-local id, so the derived-itemId match misses. Fall back to
-    # the name+position identity `addField` uses — SYMMETRIC with `addField`'s
-    # Sealed by-name reuse — so the access resolves the field `addField` produced
-    # instead of failing with `not part of closure object type`.
-    if t.state == Sealed:
-      result = lookupCapturedField(t.n, v)
-      if result != nil: break
    t = t.baseClass
    if t == nil: break
    t = t.skipTypes(skipPtrs)
--- a/compiler/magicsys.nim
+++ b/compiler/magicsys.nim
@@ -10,8 +10,8 @@
 # Built-in types and compilerprocs are registered here.

 import
-  ast, msgs, platform, idents,
-  modulegraphs, lineinfos, types
+  ast, astalgo, msgs, platform, idents,
+  modulegraphs, lineinfos

 export createMagic

@@ -134,7 +134,7 @@ proc getNimScriptSymbol*(g: ModuleGraph; name: string): PSym =
 proc resetNimScriptSymbols*(g: ModuleGraph) = g.exposed = initStrTable()

 proc getMagicEqSymForType*(g: ModuleGraph; t: PType; info: TLineInfo): PSym =
-  case t.skipTypes(abstractRange).kind
+  case t.kind
  of tyInt,  tyInt8, tyInt16, tyInt32, tyInt64,
     tyUInt, tyUInt8, tyUInt16, tyUInt32, tyUInt64:
    result = getSysMagic(g, info, "==", mEqI)
@@ -166,4 +166,4 @@ proc makeAddr*(n: PNode; idgen: IdGenerator): PNode =
    result = n
  else:
    result = newTree(nkHiddenAddr, n)
-    result.typ = makePtrType(n.typ.skipTypes({tySink}), idgen)
+    result.typ = makePtrType(n.typ, idgen)
--- a/compiler/main.nim
+++ b/compiler/main.nim
@@ -26,15 +26,11 @@ import
 when defined(nimPreviewSlimSystem):
  import std/[syncio, assertions]

+import ic / [cbackend, integrity, navigator, ic]
+
 import ../dist/checksums/src/checksums/sha1

 import pipelines
-from icconfig import produceIcConfig, ensureIcConfig
-
-when not defined(nimKochBootstrap):
-  import nifbackend
-  import deps
-  import idetools

 when not defined(leanCompiler):
  import docgen
@@ -99,6 +95,14 @@ proc commandCheck(graph: ModuleGraph) =
  setPipeLinePass(graph, SemPass)
  compilePipelineProject(graph)

+  if conf.symbolFiles != disabledSf:
+    case conf.ideCmd
+    of ideDef: navDefinition(graph)
+    of ideUse: navUsages(graph)
+    of ideDus: navDefusages(graph)
+    else: discard
+    writeRodFiles(graph)
+
 when not defined(leanCompiler):
  proc commandDoc2(graph: ModuleGraph; ext: string) =
    handleDocOutputOptions graph.config
@@ -113,38 +117,6 @@ when not defined(leanCompiler):
    else: raiseAssert $ext
    compilePipelineProject(graph)

-proc commandCompileToNif(graph: ModuleGraph) =
-  let conf = graph.config
-  extccomp.initVars(conf)
-  if conf.symbolFiles == disabledSf:
-    if {optRun, optForceFullMake} * conf.globalOptions == {optRun} or isDefined(conf, "nimBetterRun"):
-      if not changeDetectedViaJsonBuildInstructions(conf, conf.jsonBuildInstructionsFile):
-        # nothing changed
-        graph.config.notes = graph.config.mainPackageNotes
-        return
-
-  if not extccomp.ccHasSaneOverflow(conf):
-    conf.symbols.defineSymbol("nimEmulateOverflowChecks")
-
-  setPipeLinePass(graph, NifgenPass)
-  compilePipelineProject(graph)
-
-proc commandNifC(graph: ModuleGraph) =
-  ## Generate C code from precompiled NIF files.
-  ## This is the new IC approach: compile modules to NIF first with `nim m`,
-  ## then generate C code from the entry.nif file with whole-program DCE.
-  when not defined(nimKochBootstrap):
-    let conf = graph.config
-    extccomp.initVars(conf)
-
-    if not extccomp.ccHasSaneOverflow(conf):
-      conf.symbols.defineSymbol("nimEmulateOverflowChecks")
-
-    # Use the NIF backend to generate C code
-    nifbackend.generateCode(graph, conf.projectMainIdx)
-  else:
-    rawMessage(graph.config, errGenerated, "NIF backend not available during bootstrap build")
-
 proc commandCompileToC(graph: ModuleGraph) =
  let conf = graph.config
  extccomp.initVars(conf)
@@ -165,7 +137,15 @@ proc commandCompileToC(graph: ModuleGraph) =
  compilePipelineProject(graph)
  if graph.config.errorCounter > 0:
    return # issue #9933
-  cgenWriteModules(graph.backend, conf)
+  if conf.symbolFiles == disabledSf:
+    cgenWriteModules(graph.backend, conf)
+  else:
+    if isDefined(conf, "nimIcIntegrityChecks"):
+      checkIntegrity(graph)
+    generateCode(graph)
+    # graph.backend can be nil under IC when nothing changed at all:
+    if graph.backend != nil:
+      cgenWriteModules(graph.backend, conf)
  if conf.cmd != cmdTcc and graph.backend != nil:
    extccomp.callCCompiler(conf)
    # for now we do not support writing out a .json file with the build instructions when HCR is on
@@ -204,11 +184,31 @@ proc commandInteractive(graph: ModuleGraph) =
    discard graph.compilePipelineModule(fileInfoIdx(graph.config, graph.config.projectFull), {})
  else:
    var m = graph.makeStdinModule()
-    incl(m, sfMainModule)
+    incl(m.flags, sfMainModule)
    var idgen = IdGenerator(module: m.itemId.module, symId: m.itemId.item, typeId: 0)
    let s = llStreamOpenStdIn(onPrompt = proc() = flushDot(graph.config))
    discard processPipelineModule(graph, m, idgen, s)

+proc commandScan(cache: IdentCache, config: ConfigRef) =
+  var f = addFileExt(AbsoluteFile mainCommandArg(config), NimExt)
+  var stream = llStreamOpen(f, fmRead)
+  if stream != nil:
+    var
+      L: Lexer = default(Lexer)
+      tok: Token = default(Token)
+    openLexer(L, f, stream, cache, config)
+    while true:
+      rawGetTok(L, tok)
+      printTok(config, tok)
+      if tok.tokType == tkEof: break
+    closeLexer(L)
+  else:
+    rawMessage(config, errGenerated, "cannot open file: " & f.string)
+
+proc commandView(graph: ModuleGraph) =
+  let f = toAbsolute(mainCommandArg(graph.config), AbsoluteDir getCurrentDir()).addFileExt(RodExt)
+  rodViewer(f, graph.config, graph.cache)
+
 const
  PrintRopeCacheStats = false

@@ -257,7 +257,7 @@ proc mainCommand*(graph: ModuleGraph) =
      if conf.exc == excNone: conf.exc = excSetjmp
    of backendCpp:
      if conf.exc == excNone: conf.exc = excCpp
-    of backendObjc, backendNif: discard
+    of backendObjc: discard
    of backendJs:
      if conf.hcrOn:
        # XXX: At the moment, system.nim cannot be compiled in JS mode
@@ -269,35 +269,12 @@ proc mainCommand*(graph: ModuleGraph) =

  proc compileToBackend() =
    customizeForBackend(conf.backend)
-    if isIcDriver(conf):
-      # `nim c --ic:on` / `nim cpp --ic:on`: same driver as `nim ic`, entered
-      # through the ordinary compile command so every backend switch the user
-      # already knows keeps working (`nim cpp`, `--exceptions:`, `-d:`, ...).
-      # `customizeForBackend` above has already defined the backend symbol and
-      # picked the exception model, which is exactly what the per-module
-      # children must inherit — `computeForwardedArgs` forwards both.
-      setUseIc(true)
-      wantMainModule(conf)
-      setOutFile(conf)
-      when not defined(nimKochBootstrap):
-        if conf.icPreparsedConfig.len == 0:
-          # `--ic:on` came from a `nim.cfg`/`config.nims` rather than the command
-          # line, so `nim.nim` could not see it before config loading and the
-          # precompiled config the children replay does not exist yet. Produce it
-          # now. (The driver then keeps the config IT parsed instead of replaying
-          # the artifact; both come from the same files.)
-          ensureIcConfig(conf)
-        commandIc(conf)
-      else:
-        rawMessage(conf, errGenerated, "--ic:on not available in bootstrap build")
-      return
    setOutFile(conf)
    case conf.backend
    of backendC: commandCompileToC(graph)
    of backendCpp: commandCompileToC(graph)
    of backendObjc: commandCompileToC(graph)
    of backendJs: commandCompileToJS(graph)
-    of backendNif: commandCompileToNif(graph)
    of backendInvalid: raiseAssert "unreachable"

  template docLikeCmd(body) =
@@ -328,6 +305,8 @@ proc mainCommand*(graph: ModuleGraph) =
  case conf.cmd
  of cmdBackends:
    compileToBackend()
+    when BenchIC:
+      echoTimes graph.packed
  of cmdTcc:
    when hasTinyCBackend:
      extccomp.setCC(conf, "tcc", unknownLineInfo)
@@ -423,55 +402,17 @@ proc mainCommand*(graph: ModuleGraph) =
      for it in conf.searchPaths: msgWriteln(conf, it.string)
  of cmdCheck:
    commandCheck(graph)
-  of cmdTrack:
-    # `nim track --def:/--usages:/--track:` — IDE goto-definition / find-usages.
-    # Runs `nim ic`'s incremental frontend (nifler + per-module `nim m`, so only
-    # changed modules recompile and each writes a faithful, VM-executed `.s.bif`
-    # — covering stdlib too), then scans those NIF files (idetools.runIdeQuery).
-    # Shares the `nim ic` nimcache dir, so a prior `nim ic` build is reused.
-    setUseIc(true)
-    wantMainModule(conf)
-    setOutFile(conf)
-    when not defined(nimKochBootstrap):
-      commandIc(conf, frontendOnly = true)
-      runIdeQuery(conf)
-    else:
-      rawMessage(conf, errGenerated, "nim track not available in bootstrap build")
  of cmdM:
-    # cmdM uses NIF files, not ROD files
-    graph.config.symbolFiles = disabledSf
-    setUseIc(true)
-    # vtable dispatch needs a whole-program vtable layout, which the
-    # per-module compilation model cannot provide (yet); methods dispatch
-    # through the classic if-chain dispatchers instead
-    excl conf.features, Feature.vtables
+    graph.config.symbolFiles = v2Sf
+    setUseIc(graph.config.symbolFiles != disabledSf)
    commandCheck(graph)
-  of cmdNifC:
-    setUseIc(true)
-    excl conf.features, Feature.vtables
-    # Generate C code from NIF files
-    wantMainModule(conf)
-    setOutFile(conf)
-    commandNifC(graph)
-  of cmdIc:
-    # Generate .build.nif for nifmake
-    setUseIc(true)
-    wantMainModule(conf)
-    # Resolve the output binary path (honoring `--out`) up front, like cmdNifC:
-    # the backend build file derives the link target from `conf.absOutFile`.
-    setOutFile(conf)
-    when not defined(nimKochBootstrap):
-      commandIc(conf)
-    else:
-      rawMessage(conf, errGenerated, "nim deps not available in bootstrap build")
-  of cmdIcConfig:
-    # Produce the precompiled config artifact for `nim ic` (config already
-    # parsed by the normal pipeline); a separate process spawned by the driver.
-    wantMainModule(conf)
-    produceIcConfig(conf)
  of cmdParse:
    wantMainModule(conf)
    discard parseFile(conf.projectMainIdx, cache, conf)
+  of cmdRod:
+    wantMainModule(conf)
+    commandView(graph)
+    #msgWriteln(conf, "Beware: Indentation tokens depend on the parser's state!")
  of cmdInteractive: commandInteractive(graph)
  of cmdNimscript:
    if conf.projectIsCmd or conf.projectIsStdin: discard
@@ -482,17 +423,10 @@ proc mainCommand*(graph: ModuleGraph) =
  of cmdJsonscript:
    setOutFile(graph.config)
    commandJsonScript(graph)
-  of cmdUnknown, cmdNone:
+  of cmdUnknown, cmdNone, cmdIdeTools:
    rawMessage(conf, errGenerated, "invalid command: " & conf.command)

-  if conf.errorCounter == 0 and conf.cmd notin {cmdTcc, cmdDump, cmdNop, cmdM} and
-      not (conf.cmd == cmdNifC and conf.icBackendStage.len > 0):
-    # The IC build runs hundreds of internal per-module child processes — the
-    # frontend `nim m` (cmdM) and the per-module backend stages (cg/emit/merge/
-    # link). Each would print a `[SuccessX]` summary that is pure noise (and
-    # misleading: `out: unknownOutput`, or `out: <the whole compiler>` for a
-    # step that only wrote one `.c.nif`/`.c`). The driving `nim ic` (and koch)
-    # reports the real result.
+  if conf.errorCounter == 0 and conf.cmd notin {cmdTcc, cmdDump, cmdNop}:
    if optProfileVM in conf.globalOptions:
      echo conf.dump(conf.vmProfileData)
    genSuccessX(conf)
--- a/compiler/mangleutils.nim
+++ b/compiler/mangleutils.nim
@@ -53,29 +53,7 @@ proc mangleParamExt*(s: PSym): string =
  result.addInt s.position

 proc mangleProcNameExt*(graph: ModuleGraph, s: PSym): string =
-  # The disambiguator comes first and the module suffix LAST, so the suffix is
-  # a strippable trailing token: content-addressed cross-module merging chops
-  # everything from the final `__` to recover a mint-site-independent name.
-  if s.itemId.isBackendMinted:
-    # A symbol minted during IC codegen (`idGeneratorForBackend`): its idgen
-    # starts with an EMPTY per-name disamb table, so its `disamb` restarts at 0
-    # and collides with same-named sem-time symbols loaded from NIFs (two
-    # `=destroy` hooks both mangling to `_u2` → "conflicting types for ..." in
-    # the generated C). The `_c` marker keeps the namespace disjoint from
-    # `_u<disamb>`; `backendMintedDisamb` (astdef) is the ONE definition of which
-    # integer identifies such a symbol, shared with `ccgutils.makeUnique` and
-    # `ast2nif.toNifSymName` so the C name and the NIF name cannot drift apart.
-    result = "_c"
-    result.addInt backendMintedDisamb(s)
-  else:
-    result = "_u"
-    # Use `disamb` rather than `itemId.item`: under incremental compilation a
-    # symbol loaded from a NIF file gets a fresh, load-order-dependent `itemId.item`
-    # (from the per-module symbol counter), which is neither stable across the
-    # processes that compile vs. use a module nor guaranteed distinct from another
-    # loaded symbol's. `disamb` is assigned deterministically per (module, name)
-    # and, together with the already-prepended mangled name, yields a unique and
-    # stable C identifier.
-    result.addInt s.disamb
-  result.add "__"
+  result = "__"
  result.add graph.ifaces[s.itemId.module].uniqueName
+  result.add "_u"
+  result.addInt s.itemId.item # s.disamb #
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
ringabout	dd2edf4562	allows foreign functions having forward decls	2024-07-12 22:35:17 +08:00
ringabout	ca7821bea3	fixes 23827; Cyclic proc calls causes infinite memory usage in VM	2024-07-12 22:10:11 +08:00