Merge branch 'devel' into araq-generic-inst-fix

https://github.com/Yardanico/nimpylib is 404 now

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -71,5 +71,6 @@ body:
         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 (eg `choosenim 1.2.0`).
+        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)

.github/stale.yml

@@ -1,69 +0,0 @@
-# Configuration for probot-stale - https://github.com/probot/stale
-
-# Number of days of inactivity before an Issue or Pull Request becomes stale
-daysUntilStale: 365
-
-# Number of days of inactivity before an Issue or Pull Request with the stale label is closed.
-# Set to false to disable. If disabled, issues still need to be closed manually, but will remain marked as stale.
-daysUntilClose: 30
-
-# Only issues or pull requests with all of these labels are check if stale. Defaults to `[]` (disabled)
-onlyLabels: []
-
-# Issues or Pull Requests with these labels will never be considered stale. Set to `[]` to disable
-exemptLabels:
-  - ARC
-  - bounty
-  - Codegen
-  - Crash
-  - Generics
-  - High Priority
-  - Macros
-  - Next release
-  - Showstopper
-  - Static[T]
-
-# Set to true to ignore issues in a project (defaults to false)
-exemptProjects: false
-
-# Set to true to ignore issues in a milestone (defaults to false)
-exemptMilestones: false
-
-# Set to true to ignore issues with an assignee (defaults to false)
-exemptAssignees: false
-
-# Label to use when marking as stale
-staleLabel: stale
-
-# Comment to post when marking as stale. Set to `false` to disable
-markComment: >
-  This pull request has been automatically marked as stale because it has not had
-  recent activity.
-  If you think it is still a valid PR, please rebase it on the latest devel;
-  otherwise it will be closed. Thank you for your contributions.
-
-# Comment to post when removing the stale label.
-# unmarkComment: >
-#   Your comment here.
-
-# Comment to post when closing a stale Issue or Pull Request.
-# closeComment: >
-#   Your comment here.
-
-# Limit the number of actions per hour, from 1-30. Default is 30
-limitPerRun: 20
-
-# Limit to only `issues` or `pulls`
-only: pulls
-
-# Optionally, specify configuration settings that are specific to just 'issues' or 'pulls':
-# pulls:
-#   daysUntilStale: 30
-#   markComment: >
-#     This pull request has been automatically marked as stale because it has not had
-#     recent activity. It will be closed if no further activity occurs. Thank you
-#     for your contributions.
-
-# issues:
-#   exemptLabels:
-#     - confirmed

.github/workflows/bisects.yml

@@ -0,0 +1,31 @@
+# See https://github.com/juancarlospaco/nimrun-action/issues/3#issuecomment-1607344901
+name: issue comments bisects
+on:
+  issue_comment:
+    types: created
+
+jobs:
+  bisects:
+    if: |
+      github.event_name == 'issue_comment' && startsWith(github.event.comment.body, '!nim ') && github.event.issue.pull_request == null && github.event.comment.author_association != 'NONE'
+    strategy:
+      fail-fast: false
+      matrix:
+        platform: [ubuntu-latest, windows-latest, macos-latest]
+    name: ${{ matrix.platform }}-bisects
+    runs-on: ${{ matrix.platform }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: jiro4989/setup-nim-action@v1
+        with:
+          nim-version: 'devel'
+
+      - uses: juancarlospaco/nimrun-action@nim
+        if: |
+          runner.os == 'Linux'   && contains(github.event.comment.body, '-d:linux'  ) ||
+          runner.os == 'Windows' && contains(github.event.comment.body, '-d:windows') ||
+          runner.os == 'macOS'   && contains(github.event.comment.body, '-d:osx'    ) ||
+          runner.os == 'Linux' && !contains(github.event.comment.body, '-d:linux') && !contains(github.event.comment.body, '-d:windows') && !contains(github.event.comment.body, '-d:osx')
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/ci_bench.yml

@@ -0,0 +1,115 @@
+name: Benchmarks CI
+on:
+  pull_request:
+  push:
+    branches:
+      - 'devel'
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-20.04]
+        cpu: [amd64]
+    name: '${{ matrix.os }}'
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 60 # refs bug #18178
+    steps:
+      - name: 'Checkout'
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 2
+
+      - name: 'Install node.js 20.x'
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+
+      - name: 'Install dependencies (Linux amd64)'
+        if: runner.os == 'Linux' && matrix.cpu == 'amd64'
+        run: |
+          sudo apt-fast update -qq
+          DEBIAN_FRONTEND='noninteractive' \
+            sudo apt-fast install --no-install-recommends -yq \
+              libcurl4-openssl-dev libgc-dev libsdl1.2-dev libsfml-dev \
+              valgrind libc6-dbg libblas-dev xorg-dev
+
+      - name: 'Add build binaries to PATH'
+        shell: bash
+        run: echo "${{ github.workspace }}/bin" >> "${GITHUB_PATH}"
+
+      - name: 'Build csourcesAny'
+        shell: bash
+        run: . ci/funs.sh && nimBuildCsourcesIfNeeded CC=gcc ucpu='${{ matrix.cpu }}'
+
+      - name: 'Build koch'
+        shell: bash
+        run: nim c koch
+
+      - name: 'Build Nim'
+        shell: bash
+        run: ./koch boot -d:release -d:nimStrictMode --lib:lib
+
+      - name: 'Build Nimble'
+        shell: bash
+        run: ./koch nimble
+
+      - name: 'Action'
+        shell: bash
+        run: nim c -r -d:release ci/action.nim
+
+      - name: 'Checkout minimize'
+        uses: actions/checkout@v4
+        with:
+          repository: 'nim-lang/ci_bench'
+          path: minimize
+
+      - name: 'Run minimize benchmarks'
+        shell: bash
+        run: ./minimize/minimize ci-bench
+
+      - name: 'Restore minimize cached database'
+        uses: actions/cache/restore@v3
+        with:
+          path: minimize.csv
+          key: minimize-db-key
+
+      - name: 'Update minimize db'
+        shell: bash
+        run: ./minimize/minimize update-db
+
+      - name: 'Save minimize cached database'
+        if: |
+          github.event_name == 'push' && github.ref == 'refs/heads/devel' &&
+          matrix.target == 'linux'
+        uses: actions/cache/save@v3
+        with:
+          path: minimize.csv
+          key: minimize-db-key
+
+      - name: 'Generate minimize report'
+        shell: bash
+        run: ./minimize/minimize generate-report
+
+      - name: 'Archive minimize report'
+        uses: actions/upload-artifact@v3
+        with:
+          name: minimize-report
+          path: |
+            minimize/minimize.html
+            minimize/minimize.csv
+
+      # Requires additional permissions, see:
+      # https://github.com/nim-lang/Nim/actions/runs/4778177321/jobs/8494423792?pr=21566
+      # - name: 'Publish HTML report'
+      #   uses: rossjrw/pr-preview-action@v1
+      #   with:
+      #     source-dir: minimize
+      #     umbrella-dir: minimize
+      #   env:
+      #     GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract md summary
+        run: |
+          cat minimize/summary.md  >> $GITHUB_STEP_SUMMARY

.github/workflows/ci_docs.yml

@@ -2,8 +2,7 @@ name: Nim Docs CI
 on:
   push:
     paths:
-      - 'compiler/docgen.nim'
-      - 'compiler/renderverbatim.nim'
+      - 'compiler/**.nim'
       - 'config/nimdoc.cfg'
       - 'doc/**.rst'
       - 'doc/**.md'
@@ -18,8 +17,7 @@ on:
   pull_request:
     # Run only on changes on these files.
     paths:
-      - 'compiler/docgen.nim'
-      - 'compiler/renderverbatim.nim'
+      - 'compiler/**.nim'
       - 'config/nimdoc.cfg'
       - 'doc/**.rst'
       - 'doc/**.md'
@@ -47,7 +45,7 @@ jobs:
           - target: windows
             os: windows-2019
           - target: osx
-            os: macos-11
+            os: macos-12
 
     name: ${{ matrix.target }}
     runs-on: ${{ matrix.os }}
@@ -55,7 +53,7 @@ jobs:
 
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 2
 
@@ -111,7 +109,7 @@ jobs:
         if: |
           github.event_name == 'push' && github.ref == 'refs/heads/devel' &&
           matrix.target == 'linux'
-        uses: crazy-max/ghaction-github-pages@v3
+        uses: crazy-max/ghaction-github-pages@v4
         with:
           build_dir: doc/html
         env:

.github/workflows/ci_packages.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04, macos-11]
+        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 }})'
@@ -28,14 +28,14 @@ jobs:
       NIM_TESTAMENT_BATCH: ${{ matrix.batch }}
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 2
 
-      - name: 'Install node.js 16.x'
-        uses: actions/setup-node@v3
+      - name: 'Install node.js 20.x'
+        uses: actions/setup-node@v4
         with:
-          node-version: '16.x'
+          node-version: '20.x'
 
       - name: 'Install dependencies (Linux amd64)'
         if: runner.os == 'Linux' && matrix.cpu == 'amd64'

.github/workflows/ci_publish.yml

@@ -17,14 +17,14 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 2
 
-      - name: 'Install node.js 16.x'
-        uses: actions/setup-node@v3
+      - name: 'Install node.js 20.x'
+        uses: actions/setup-node@v4
         with:
-          node-version: '16.x'
+          node-version: '20.x'
 
       - name: 'Install dependencies (Linux amd64)'
         if: runner.os == 'Linux' && matrix.cpu == 'amd64'
@@ -71,7 +71,7 @@ jobs:
         run: nim c -r -d:release ci/action.nim
 
       - name: 'Comment'
-        uses: actions/github-script@v6
+        uses: actions/github-script@v7
         with:
           script: |
             const fs = require('fs');

.github/workflows/stale.yml

@@ -0,0 +1,25 @@
+# https://github.com/actions/stale#usage
+name: Stale pull requests
+
+on:
+  schedule:
+    - cron: '0 0 * * *'  # Midnight.
+
+jobs:
+  stale:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/stale@v9
+        with:
+          days-before-pr-stale:    365
+          days-before-pr-close:    30
+          days-before-issue-stale: -1
+          days-before-issue-close: -1
+          exempt-pr-labels:    "ARC,bounty,Codegen,Crash,Generics,High Priority,Macros,Next release,Showstopper,Static[T]"
+          exempt-issue-labels: "Showstopper,Severe,bounty,Compiler Crash,Medium Priority"
+          stale-pr-message: >
+            This pull request is stale because it has been open for 1 year with no activity.
+            Contribute more commits on the pull request and rebase it on the latest devel,
+            or it will be closed in 30 days. Thank you for your contributions.
+          close-pr-message: >
+            This pull request has been marked as stale and closed due to inactivity after 395 days.

.gitignore

@@ -110,3 +110,5 @@ htmldocs
 nimdoc.out.css
 # except here:
 !/nimdoc/testproject/expected/*
+pkgs/
+/compiler/compiler/

.gitlab-ci.yml

@@ -1,62 +0,0 @@
-# xxx unused, out of date
-
-image: ubuntu:18.04
-
-stages:
-  - pre-build
-  - build
-  - deploy
-  - test
-
-.linux_set_path: &linux_set_path_def
-  before_script:
-    - export PATH=$(pwd)/bin${PATH:+:$PATH}
-  tags:
-    - linux
-
-.windows_set_path: &win_set_path_def
-  before_script:
-    - set PATH=%CD%\bin;%PATH%
-  tags:
-    - windows
-
-
-build-windows:
-  stage: build
-  script:
-    - ci\build.bat
-  artifacts:
-    paths:
-      - bin\nim.exe
-      - bin\nimd.exe
-      - compiler\nim.exe
-      - koch.exe
-    expire_in: 1 week
-  tags:
-    - windows
-
-deploy-windows:
-  stage: deploy
-  script:
-    - koch.exe winrelease
-  artifacts:
-    paths:
-      - build/*.exe
-      - build/*.zip
-    expire_in: 1 week
-  tags:
-    - windows
-    - fast
-
-
-
-test-windows:
-  stage: test
-  <<: *win_set_path_def
-  script:
-    - call ci\deps.bat
-    - nim c testament\tester
-    - testament\tester.exe all
-  tags:
-    - windows
-    - fast

azure-pipelines.yml

@@ -23,16 +23,16 @@ jobs:
         vmImage: 'ubuntu-20.04'
         CPU: amd64
       # regularly breaks, refs bug #17325
-      Linux_i386:
-        # on 'ubuntu-16.04' (not supported anymore anyways) it errored with:
-        # g++-multilib : Depends: gcc-multilib (>= 4:5.3.1-1ubuntu1) but it is not going to be installed
-        vmImage: 'ubuntu-18.04'
-        CPU: i386
+#       Linux_i386:
+#         # on 'ubuntu-16.04' (not supported anymore anyways) it errored with:
+#         # 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_amd64:
-        vmImage: 'macOS-11'
+        vmImage: 'macOS-12'
         CPU: amd64
       OSX_amd64_cpp:
-        vmImage: 'macOS-11'
+        vmImage: 'macOS-12'
         CPU: amd64
         NIM_COMPILE_TO_CPP: true
       Windows_amd64_batch0_3:
@@ -73,8 +73,8 @@ jobs:
 
     - task: NodeTool@0
       inputs:
-        versionSpec: '16.x'
-      displayName: 'Install node.js 16.x'
+        versionSpec: '20.x'
+      displayName: 'Install node.js 20.x'
       condition: and(succeeded(), eq(variables['skipci'], 'false'))
 
     - bash: |

changelog.md

@@ -3,29 +3,108 @@
 
 ## Changes affecting backward compatibility
 
+- `-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.
+
+- `bindMethod` in `std/jsffi` is deprecated, don't use it with closures.
 
 ## Standard library additions and changes
 
 [//]: # "Changes:"
 
+- 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 `parseutils.parseSize` - inverse to `strutils.formatSize` - to parse human readable sizes.
+
+- Added `newStringUninit` to system, which creates a new string of length `len` like `newString` but with uninitialized content.
+- Added `setLenUninit` to system, which doesn't initalize
+slots when enlarging a sequence.
+- Added `hasDefaultValue` to `std/typetraits` to check if a type has a valid default value.
+- Added Viewport API for the JavaScript targets in the `dom` module.
+- 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`.
 
 [//]: # "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.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
+  const value = "captured"
+  template foo(x: int, body: 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:genericsOpenSym`
+  echo old[int]() # "captured"
+
+  {.experimental: "genericsOpenSym".}
+
+  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"
+  ```
 
 ## 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 in tow.
+

changelogs/changelog_2_0_0.md

@@ -1,367 +1,330 @@
-# v2.0.0 - yyyy-mm-dd
+# v2.0.0 - 2023-08-01
 
+Version 2.0 is a big milestone with too many changes to list them all here.
 
-## Changes affecting backward compatibility
-- `httpclient.contentLength` default to `-1` if the Content-Length header is not set in the response. It follows Apache HttpClient(Java), http(go) and .Net HttpWebResponse(C#) behavior. Previously it raised `ValueError`.
+For a full list see [details](changelog_2_0_0_details.html).
 
-- `addr` is now available for all addressable locations,
-  `unsafeAddr` is now deprecated and an alias for `addr`.
 
-- Certain definitions from the default `system` module have been moved to
-  the following new modules:
+## New features
 
-  - `std/syncio`
-  - `std/assertions`
-  - `std/formatfloat`
-  - `std/objectdollar`
-  - `std/widestrs`
-  - `std/typedthreads`
-  - `std/sysatomics`
+### Better tuple unpacking
 
-  In the future, these definitions will be removed from the `system` module,
-  and their respective modules will have to be imported to use them.
-  Currently, to make these imports required, the `-d:nimPreviewSlimSystem` option
-  may be used.
+Tuple unpacking for variables is now treated as syntax sugar that directly
+expands into multiple assignments. Along with this, tuple unpacking for
+variables can now be nested.
 
-- Enabling `-d:nimPreviewSlimSystem` also removes the following deprecated
-  symbols in the `system` module:
-  - Aliases with `Error` suffix to exception types that have a `Defect` suffix
-    (see [exceptions](https://nim-lang.github.io/Nim/exceptions.html)):
-    `ArithmeticError`, `DivByZeroError`, `OverflowError`,
-    `AccessViolationError`, `AssertionError`, `OutOfMemError`, `IndexError`,
-    `FieldError`, `RangeError`, `StackOverflowError`, `ReraiseError`,
-    `ObjectAssignmentError`, `ObjectConversionError`, `FloatingPointError`,
-    `FloatOverflowError`, `FloatUnderflowError`, `FloatInexactError`,
-    `DeadThreadError`, `NilAccessError`
-  - `addQuitProc`, replaced by `exitprocs.addExitProc`
-  - Legacy unsigned conversion operations: `ze`, `ze64`, `toU8`, `toU16`, `toU32`
-  - `TaintedString`, formerly a distinct alias to `string`
-  - `PInt32`, `PInt64`, `PFloat32`, `PFloat64`, aliases to
-    `ptr int32`, `ptr int64`, `ptr float32`, `ptr float64`
+```nim
+proc returnsNestedTuple(): (int, (int, int), int, int) = (4, (5, 7), 2, 3)
 
-- Enabling `-d:nimPreviewSlimSystem` removes the import of `channels_builtin` in
-  in the `system` module.
+# Now nesting is supported!
+let (x, (_, y), _, z) = returnsNestedTuple()
 
-- Enabling `-d:nimPreviewCstringConversion`, `ptr char`, `ptr array[N, char]` and `ptr UncheckedArray[N, char]` don't support conversion to cstring anymore.
+```
 
-- The `gc:v2` option is removed.
+### Improved type inference
 
-- The `mainmodule` and `m` options are removed.
+A new form of type inference called [top-down inference](https://nim-lang.github.io/Nim/manual_experimental.html#topminusdown-type-inference) has been implemented for a variety of basic cases.
 
-- The `threads:on` option is now the default.
+For example, code like the following now compiles:
 
-- Optional parameters in combination with `: body` syntax (RFC #405) are now opt-in via
-  `experimental:flexibleOptionalParams`.
+```nim
+let foo: seq[(float, byte, cstring)] = @[(1, 2, "abc")]
+```
 
-- Automatic dereferencing (experimental feature) is removed.
+### Forbidden Tags
 
-- The `Math.trunc` polyfill for targeting Internet Explorer was
-  previously included in most JavaScript output files.
-  Now, it is only included with `-d:nimJsMathTruncPolyfill`.
-  If you are targeting Internet Explorer, you may choose to enable this option
-  or define your own `Math.trunc` polyfill using the [`emit` pragma](https://nim-lang.org/docs/manual.html#implementation-specific-pragmas-emit-pragma).
-  Nim uses `Math.trunc` for the division and modulo operators for integers.
+[Tag tracking](https://nim-lang.github.io/Nim/manual.html#effect-system-tag-tracking) now supports the definition
+of forbidden tags by the `.forbids` pragma which can be used to disable certain effects in proc types.
 
-- `shallowCopy` and `shallow` are removed for ARC/ORC. Use `move` when possible or combine assignment and
-`sink` for optimization purposes.
+For example:
 
-- The experimental `nimPreviewDotLikeOps` switch is going to be removed or deprecated because it didn't fullfill its promises.
+```nim
 
-- The `{.this.}` pragma, deprecated since 0.19, has been removed.
-- `nil` literals can no longer be directly assigned to variables or fields of `distinct` pointer types. They must be converted instead.
-  ```nim
-  type Foo = distinct ptr int
-
-  # Before:
-  var x: Foo = nil
-  # After:
-  var x: Foo = Foo(nil)
-  ```
-- Removed two type pragma syntaxes deprecated since 0.20, namely
-  `type Foo = object {.final.}`, and `type Foo {.final.} [T] = object`.
-
-- `foo a = b` now means `foo(a = b)` rather than `foo(a) = b`. This is consistent
-  with the existing behavior of `foo a, b = c` meaning `foo(a, b = c)`.
-  This decision was made with the assumption that the old syntax was used rarely;
-  if your code used the old syntax, please be aware of this change.
-
-- [Overloadable enums](https://nim-lang.github.io/Nim/manual.html#overloadable-enum-value-names) and Unicode Operators
-  are no longer experimental.
+type IO = object ## input/output effect
+proc readLine(): string {.tags: [IO].} = discard
+proc echoLine(): void = discard
 
-- Removed the `nimIncrSeqV3` define.
+proc no_IO_please() {.forbids: [IO].} =
+  # this is OK because it didn't define any tag:
+  echoLine()
+  # the compiler prevents this:
+  let y = readLine()
 
-- `macros.getImpl` for `const` symbols now returns the full definition node
-  (as `nnkConstDef`) rather than the AST of the constant value.
+```
 
-- Lock levels are deprecated, now a noop.
+### New standard library modules
 
-- ORC is now the default memory management strategy. Use
-  `--mm:refc` for a transition period.
-
-- `strictEffects` are no longer experimental.
-  Use `legacy:laxEffects` to keep backward compatibility.
-
-- The `gorge`/`staticExec` calls will now return a descriptive message in the output
-  if the execution fails for whatever reason. To get back legacy behaviour use `-d:nimLegacyGorgeErrors`.
-
-- Pointer to `cstring` conversion now triggers a `[PtrToCstringConv]` warning.
-  This warning will become an error in future versions! Use a `cast` operation
-  like `cast[cstring](x)` instead.
-
-- `logging` will default to flushing all log level messages. To get the legacy behaviour of only flushing Error and Fatal messages, use `-d:nimV1LogFlushBehavior`.
-
-- Redefining templates with the same signature was previously
-  allowed to support certain macro code. To do this explicitly, the
-  `{.redefine.}` pragma has been added. Note that this is only for templates.
-  Implicit redefinition of templates is now deprecated and will give an error in the future.
-
-- Using an unnamed break in a block is deprecated. This warning will become an error in future versions! Use a named block with a named break instead.
-
-- Several Standard libraries are moved to nimble packages, use `nimble` to install them:
-  - `std/punycode` => `punycode`
-  - `std/asyncftpclient` => `asyncftpclient`
-  - `std/smtp` => `smtp`
-  - `std/db_common` => `db_connector/db_common`
-  - `std/db_sqlite` => `db_connector/db_sqlite`
-  - `std/db_mysql` => `db_connector/db_mysql`
-  - `std/db_postgres` => `db_connector/db_postgres`
-  - `std/db_odbc` => `db_connector/db_odbc`
-
-- Previously, calls like `foo(a, b): ...` or `foo(a, b) do: ...` where the final argument of
-  `foo` had type `proc ()` were assumed by the compiler to mean `foo(a, b, proc () = ...)`.
-  This behavior is now deprecated. Use `foo(a, b) do (): ...` or `foo(a, b, proc () = ...)` instead.
-
-- If no exception or any exception deriving from Exception but not Defect or CatchableError given in except, a `warnBareExcept` warning will be triggered.
-
-- The experimental strictFuncs feature now disallows a store to the heap via a `ref` or `ptr` indirection.
-
-- Underscores (`_`) as routine parameters are now ignored and cannot be used in the routine body.
-  The following code now does not compile:
-
-  ```nim
-  proc foo(_: int): int = _ + 1
-  echo foo(1)
-  ```
-
-  Instead, the following code now compiles:
-
-  ```nim
-  proc foo(_, _: int): int = 123
-  echo foo(1, 2)
-  ```
-- Underscores (`_`) as generic parameters are not supported and cannot be used.
-  Generics that use `_` as parameters will no longer compile requires you to replace `_` with something else:
-  
-  ```nim
-  proc foo[_](t: typedesc[_]): string = "BAR" # Can not compile
-  proc foo[T](t: typedesc[T]): string = "BAR" # Can compile
-  ```
-
-- - Added the `--legacy:verboseTypeMismatch` switch to get legacy type mismatch error messages.
-
-## Standard library additions and changes
-
-[//]: # "Changes:"
-- OpenSSL 3 is now supported.
-- `macros.parseExpr` and `macros.parseStmt` now accept an optional
-  filename argument for more informative errors.
-- Module `colors` expanded with missing colors from the CSS color standard.
-  `colPaleVioletRed` and `colMediumPurple` have also been changed to match the CSS color standard.
-- Fixed `lists.SinglyLinkedList` being broken after removing the last node ([#19353](https://github.com/nim-lang/Nim/pull/19353)).
-- The `md5` module now works at compile time and in JavaScript.
-- Changed `mimedb` to use an `OrderedTable` instead of `OrderedTableRef` to support `const` tables.
-- `strutils.find` now uses and defaults to `last = -1` for whole string searches,
-  making limiting it to just the first char (`last = 0`) valid.
-- `random.rand` now works with `Ordinal`s.
-- Undeprecated `os.isvalidfilename`.
-- `std/oids` now uses `int64` to store time internally (before it was int32).
-- `std/uri.Uri` dollar `$` improved, precalculates the `string` result length from the `Uri`.
-- `std/uri.Uri.isIpv6` is now exported.
-- `std/logging.ConsoleLogger` and `FileLogger` now have a `flushThreshold` attribute to set what log message levels are automatically flushed. For Nim v1 use `-d:nimFlushAllLogs` to automatically flush all message levels. Flushing all logs is the default behavior for Nim v2.
-
-
-- `std/net.IpAddress` dollar `$` improved, uses a fixed capacity for the `string` result based from the `IpAddressFamily`.
-- `std/jsfetch.newFetchOptions` now has default values for all parameters
-- `std/jsformdata` now accepts `Blob` data type.
-
-- `std/sharedlist` and `std/sharedtables` are now deprecated, see RFC [#433](https://github.com/nim-lang/RFCs/issues/433).
-
-- New compile flag (`-d:nimNoGetRandom`) when building `std/sysrand` to remove dependency on linux `getrandom` syscall.
-
-  This compile flag only affects linux builds and is necessary if either compiling on a linux kernel version < 3.17, or if code built will be executing on kernel < 3.17.
-
-  On linux kernels < 3.17 (such as kernel 3.10 in RHEL7 and CentOS7), the `getrandom` syscall was not yet introduced. Without this, the `std/sysrand` module will not build properly, and if code is built on a kernel >= 3.17 without the flag, any usage of the `std/sysrand` module will fail to execute on a kernel < 3.17 (since it attempts to perform a syscall to `getrandom`, which isn't present in the current kernel). A compile flag has been added to force the `std/sysrand` module to use /dev/urandom (available since linux kernel 1.3.30), rather than the `getrandom` syscall. This allows for use of a cryptographically secure PRNG, regardless of kernel support for the `getrandom` syscall.
-
-  When building for RHEL7/CentOS7 for example, the entire build process for nim from a source package would then be:
-  ```sh
-  $ yum install devtoolset-8 # Install GCC version 8 vs the standard 4.8.5 on RHEL7/CentOS7. Alternatively use -d:nimEmulateOverflowChecks. See issue #13692 for details
-  $ scl enable devtoolset-8 bash # Run bash shell with default toolchain of gcc 8
-  $ sh build.sh  # per unix install instructions
-  $ bin/nim c koch  # per unix install instructions
-  $ ./koch boot -d:release  # per unix install instructions
-  $ ./koch tools -d:nimNoGetRandom  # pass the nimNoGetRandom flag to compile std/sysrand without support for getrandom syscall
-  ```
-
-  This is necessary to pass when building nim on kernel versions < 3.17 in particular to avoid an error of "SYS_getrandom undeclared" during the build process for stdlib (sysrand in particular).
-
-[//]: # "Additions:"
-- Added ISO 8601 week date utilities in `times`:
-  - Added `IsoWeekRange`, a range type for weeks in a week-based year.
-  - Added `IsoYear`, a distinct type for a week-based year in contrast to a regular year.
-  - Added a `initDateTime` overload to create a datetime from an ISO week date.
-  - Added `getIsoWeekAndYear` to get an ISO week number and week-based year from a datetime.
-  - Added `getIsoWeeksInYear` to return the number of weeks in a week-based year.
-- Added new modules which were part of `std/os`:
-  - Added `std/oserrors` for OS error reporting. Added `std/envvars` for environment variables handling.
-  - Added `std/paths`, `std/dirs`, `std/files`, `std/symlinks` and `std/appdirs`.
-  - Added `std/cmdline` for reading command line parameters.
-- Added `sep` parameter in `std/uri` to specify the query separator.
-- Added bindings to [`Array.shift`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift)
-  and [`queueMicrotask`](https://developer.mozilla.org/en-US/docs/Web/API/queueMicrotask)
-  in `jscore` for JavaScript targets.
-- Added `UppercaseLetters`, `LowercaseLetters`, `PunctuationChars`, `PrintableChars` sets to `std/strutils`.
-- Added `complex.sgn` for obtaining the phase of complex numbers.
-- Added `insertAdjacentText`, `insertAdjacentElement`, `insertAdjacentHTML`,
-  `after`, `before`, `closest`, `append`, `hasAttributeNS`, `removeAttributeNS`,
-  `hasPointerCapture`, `releasePointerCapture`, `requestPointerLock`,
-  `replaceChildren`, `replaceWith`, `scrollIntoViewIfNeeded`, `setHTML`,
-  `toggleAttribute`, and `matches` to `std/dom`.
-- Added [`jsre.hasIndices`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/hasIndices)
-- Added `capacity` for `string` and `seq` to return the current capacity, see https://github.com/nim-lang/RFCs/issues/460
-- Added `openArray[char]` overloads for `std/parseutils` allowing more code reuse.
-- Added `openArray[char]` overloads for `std/unicode` allowing more code reuse.
-- Added `safe` parameter to `base64.encodeMime`.
-
-[//]: # "Deprecations:"
-- Deprecated `selfExe` for Nimscript.
-- Deprecated `std/sums`.
-- Deprecated `std/base64.encode` for collections of arbitrary integer element type.
-  Now only `byte` and `char` are supported.
-
-[//]: # "Removals:"
-- Removed deprecated module `parseopt2`.
-- Removed deprecated module `sharedstrings`.
-- Removed deprecated module `dom_extensions`.
-- Removed deprecated module `LockFreeHash`.
-- Removed deprecated module `events`.
-- Removed deprecated `oids.oidToString`.
-- Removed define `nimExperimentalAsyncjsThen` for `std/asyncjs.then` and `std/jsfetch`.
-- Removed deprecated `jsre.test` and `jsre.toString`.
-- Removed deprecated `math.c_frexp`.
-- Removed deprecated `` httpcore.`==` ``.
-- Removed deprecated `std/posix.CMSG_SPACE` and `std/posix.CMSG_LEN` that takes wrong argument types.
-- Removed deprecated `osproc.poDemon`, symbol with typo.
-- Removed deprecated `tables.rightSize`.
-
-
-- Removed deprecated `posix.CLONE_STOPPED`.
-
-
-## Language changes
-
-- [Tag tracking](https://nim-lang.github.io/Nim/manual.html#effect-system-tag-tracking) supports the definition of forbidden tags by the `.forbids` pragma
-  which can be used to disable certain effects in proc types.
-- [Case statement macros](https://nim-lang.github.io/Nim/manual.html#macros-case-statement-macros) are no longer experimental,
-  meaning you no longer need to enable the experimental switch `caseStmtMacros` to use them.
-- Full command syntax and block arguments i.e. `foo a, b: c` are now allowed
-  for the right-hand side of type definitions in type sections. Previously
-  they would error with "invalid indentation".
-
-- Compile-time define changes:
-  - `defined` now accepts identifiers separated by dots, i.e. `defined(a.b.c)`.
-    In the command line, this is defined as `-d:a.b.c`. Older versions can
-    use accents as in ``defined(`a.b.c`)`` to access such defines.
-  - [Define pragmas for constants](https://nim-lang.github.io/Nim/manual.html#implementation-specific-pragmas-compileminustime-define-pragmas)
-    now support a string argument for qualified define names.
-
-    ```nim
-    # -d:package.FooBar=42
-    const FooBar {.intdefine: "package.FooBar".}: int = 5
-    echo FooBar # 42
-    ```
-
-    This was added to help disambiguate similar define names for different packages.
-    In older versions, this could only be achieved with something like the following:
-
-    ```nim
-    const FooBar = block:
-      const `package.FooBar` {.intdefine.}: int = 5
-      `package.FooBar`
-    ```
-  - A generic `define` pragma for constants has been added that interprets
-    the value of the define based on the type of the constant value.
-    See the [experimental manual](https://nim-lang.github.io/Nim/manual_experimental.html#generic-define-pragma)
-    for a list of supported types.
-
-- [Macro pragmas](https://nim-lang.github.io/Nim/manual.html#userminusdefined-pragmas-macro-pragmas) changes:
-  - Templates now accept macro pragmas.
-  - Macro pragmas for var/let/const sections have been redesigned in a way that works
-    similarly to routine macro pragmas. The new behavior is documented in the
-    [experimental manual](https://nim-lang.github.io/Nim/manual_experimental.html#extended-macro-pragmas).
-  - Pragma macros on type definitions can now return `nnkTypeSection` nodes as well as `nnkTypeDef`,
-    allowing multiple type definitions to be injected in place of the original type definition.
-
-    ```nim
-    import macros
-    macro multiply(amount: static int, s: untyped): untyped =
-      let name = $s[0].basename
-      result = newNimNode(nnkTypeSection)
-      for i in 1 .. amount:
-        result.add(newTree(nnkTypeDef, ident(name & $i), s[1], s[2]))
-    type
-      Foo = object
-      Bar {.multiply: 3.} = object
-        x, y, z: int
-      Baz = object
-    # becomes
-    type
-      Foo = object
-      Bar1 = object
-        x, y, z: int
-      Bar2 = object
-        x, y, z: int
-      Bar3 = object
-        x, y, z: int
-      Baz = object
-    ```
-
-- A new form of type inference called [top-down inference](https://nim-lang.github.io/Nim/manual_experimental.html#topminusdown-type-inference)
-  has been implemented for a variety of basic cases. For example, code like the following now compiles:
-
-  ```nim
-  let foo: seq[(float, byte, cstring)] = @[(1, 2, "abc")]
-  ```
-
-- `cstring` is now accepted as a selector in `case` statements, removing the
-  need to convert to `string`. On the JS backend, this is translated directly
-  to a `switch` statement.
-
-- Nim now supports `out` parameters and ["strict definitions"](https://nim-lang.github.io/Nim/manual_experimental.html#strict-definitions-and-nimout-parameters).
-- Nim now offers a [strict mode](https://nim-lang.github.io/Nim/manual_experimental.html#strict-case-objects) for `case objects`.
-
-- IBM Z architecture and macOS m1 arm64 architecture are supported.
-
-- `=wasMoved` can be overridden by users.
-
-## Compiler changes
-
-- The `gc` switch has been renamed to `mm` ("memory management") in order to reflect the
-  reality better. (Nim moved away from all techniques based on "tracing".)
-
-- Defines the `gcRefc` symbol which allows writing specific code for the refc GC.
-
-- `nim` can now compile version 1.4.0 as follows: `nim c --lib:lib --stylecheck:off compiler/nim`,
-  without requiring `-d:nimVersion140` which is now a noop.
-
-- `--styleCheck`, `--hintAsError` and `--warningAsError` now only apply to the current package.
-
-- The switch `--nimMainPrefix:prefix` has been added to add a prefix to the names of `NimMain` and
-  related functions produced on the backend. This prevents conflicts with other Nim
-  static libraries.
-
-- When compiling for Release the flag `-fno-math-errno` is used for GCC.
+The famous `os` module got an overhaul. Several of its features are available
+under a new interface that introduces a `Path` abstraction. A `Path` is
+a `distinct string`, which improves the type safety when dealing with paths, files
+and directories.
+
+Use:
+
+- `std/oserrors` for OS error reporting.
+- `std/envvars` for environment variables handling.
+- `std/paths` for path handling.
+- `std/dirs` for directory creation/deletion/traversal.
+- `std/files` for file existence checking, file deletions and moves.
+- `std/symlinks` for symlink handling.
+- `std/appdirs` for accessing configuration/home/temp directories.
+- `std/cmdline` for reading command line parameters.
+
+### Consistent underscore handling
+
+The underscore identifier (`_`) is now generally not added to scope when
+used as the name of a definition. While this was already the case for
+variables, it is now also the case for routine parameters, generic
+parameters, routine declarations, type declarations, etc. This means that the following code now does not compile:
+
+```nim
+proc foo(_: int): int = _ + 1
+echo foo(1)
+
+proc foo[_](t: typedesc[_]): seq[_] = @[default(_)]
+echo foo[int]()
+
+proc _() = echo "_"
+_()
+
+type _ = int
+let x: _ = 3
+```
+
+Whereas the following code now compiles:
+
+```nim
+proc foo(_, _: int): int = 123
+echo foo(1, 2)
+
+proc foo[_, _](): int = 123
+echo foo[int, bool]()
+
+proc foo[T, U](_: typedesc[T], _: typedesc[U]): (T, U) = (default(T), default(U))
+echo foo(int, bool)
+
+proc _() = echo "one"
+proc _() = echo "two"
+
+type _ = int
+type _ = float
+```
+
+### JavaScript codegen improvement
+
+The JavaScript backend now uses [BigInt](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt)
+for 64-bit integer types (`int64` and `uint64`) by default. As this affects
+JS code generation, code using these types to interface with the JS backend
+may need to be updated. Note that `int` and `uint` are not affected.
+
+For compatibility with [platforms that do not support BigInt](https://caniuse.com/bigint)
+and in the case of potential bugs with the new implementation, the
+old behavior is currently still supported with the command line option
+`--jsbigint64:off`.
+
+
+## Docgen improvements
+
+`Markdown` is now the default markup language of doc comments (instead
+of the legacy `RstMarkdown` mode). In this release we begin to separate
+RST and Markdown features to better follow specification of each
+language, with the focus on Markdown development.
+See also [the docs](https://nim-lang.github.io/Nim/markdown_rst.html).
+
+* Added a `{.doctype: Markdown | RST | RstMarkdown.}` pragma allowing to
+  select the markup language mode in the doc comments of the current `.nim`
+  file for processing by `nim doc`:
+
+    1. `Markdown` (default) is basically CommonMark (standard Markdown) +
+        some Pandoc Markdown features + some RST features that are missing
+        in our current implementation of CommonMark and Pandoc Markdown.
+    2. `RST` closely follows the RST spec with few additional Nim features.
+    3. `RstMarkdown` is a maximum mix of RST and Markdown features, which
+        is kept for the sake of compatibility and ease of migration.
+
+* Added separate `md2html` and `rst2html` commands for processing
+  standalone `.md` and `.rst` files respectively (and also `md2tex`/`rst2tex`).
+
+* Added Pandoc Markdown bracket syntax `[...]` for making anchor-less links.
+* Docgen now supports concise syntax for referencing Nim symbols:
+  instead of specifying HTML anchors directly one can use original
+  Nim symbol declarations (adding the aforementioned link brackets
+  `[...]` around them).
+  * To use this feature across modules, a new `importdoc` directive was added.
+    Using this feature for referencing also helps to ensure that links
+    (inside one module or the whole project) are not broken.
+* Added support for RST & Markdown quote blocks (blocks starting with `>`).
+* Added a popular Markdown definition lists extension.
+* Added Markdown indented code blocks (blocks indented by >= 4 spaces).
+* Added syntax for additional parameters to Markdown code blocks:
+
+       ```nim test="nim c $1"
+       ...
+       ```
+
+
+## C++ interop enhancements
+
+Nim 2.0 takes C++ interop to the next level. With the new [virtual](https://nim-lang.github.io/Nim/manual_experimental.html#virtual-pragma) pragma and the extended [constructor](https://nim-lang.github.io/Nim/manual_experimental.html#constructor-pragma) pragma.
+Now one can define constructors and virtual procs that maps to C++ constructors and virtual methods, allowing one to further customize
+the interoperability. There is also extended support for the [codeGenDecl](https://nim-lang.org/docs/manual.html#implementation-specific-pragmas-codegendecl-pragma) pragma, so that it works on types.
+
+It's a common pattern in C++ to use inheritance to extend a library. Some even use multiple inheritance as a mechanism to make interfaces.
+
+Consider the following example:
+
+```cpp
+
+struct Base {
+  int someValue;
+  Base(int inValue)  {
+    someValue = inValue;
+  };
+};
+
+class IPrinter {
+public:
+  virtual void print() = 0;
+};
+```
+
+```nim
+
+type
+  Base* {.importcpp, inheritable.} = object
+    someValue*: int32
+  IPrinter* {.importcpp.} = object
+
+const objTemplate = """
+  struct $1 : public $3, public IPrinter {
+    $2
+  };
+""";
+
+type NimChild {.codegenDecl: objTemplate .} = object of Base
+
+proc makeNimChild(val: int32): NimChild {.constructor: "NimClass('1 #1) : Base(#1)".} =
+  echo "It calls the base constructor passing " & $this.someValue
+  this.someValue = val * 2 # Notice how we can access `this` inside the constructor. It's of the type `ptr NimChild`.
+
+proc print*(self: NimChild) {.virtual.} =
+  echo "Some value is " & $self.someValue
+
+let child = makeNimChild(10)
+child.print()
+```
+
+It outputs:
+
+```
+It calls the base constructor passing 10
+Some value is 20
+```
+
+
+## ARC/ORC refinements
+
+With the 2.0 release, the ARC/ORC model got refined once again and is now finally complete:
+
+1. Programmers now have control over the "item was moved from" state as `=wasMoved` is overridable.
+2. There is a new `=dup` hook which is more efficient than the old combination of `=wasMoved(tmp); =copy(tmp, x)` operations.
+3. Destructors now take a parameter of the attached object type `T` directly and don't have to take a `var T` parameter.
+
+With these important optimizations we improved the runtime of the compiler and important benchmarks by 0%! Wait ... what?
+Yes, unfortunately it turns out that for a modern optimizer like in GCC or LLVM there is no difference.
+
+But! This refined model is more efficient once separate compilation enters the picture. In other words, as we think of
+providing a stable ABI it is important not to lose any efficiency in the calling conventions.
 
 
 ## Tool changes
 
-- Nim now ships Nimble version 0.14 which added support for lock-files. Libraries are stored in `$nimbleDir/pkgs2` (it was `$nimbleDir/pkgs`).
+- Nim now ships Nimble version 0.14 which added support for lock-files. Libraries are stored in `$nimbleDir/pkgs2` (it was `$nimbleDir/pkgs` before). Use `nimble develop --global` to create an old style link file in the special links directory documented at https://github.com/nim-lang/nimble#nimble-develop.
+- nimgrep now offers the option `--inContext` (and `--notInContext`), which
+  allows to filter only matches with the context block containing a given pattern.
+- nimgrep: names of options containing "include/exclude" are deprecated,
+  e.g. instead of `--includeFile` and `--excludeFile` we have
+  `--filename` and `--notFilename` respectively.
+  Also, the semantics are now consistent for such positive/negative filters.
+- Nim now ships with an alternative package manager called Atlas. More on this in upcoming versions.
+
+
+## Porting guide
+
+### Block and Break
+
+Using an unnamed break in a block is deprecated. This warning will become an error in future versions! Use a named block with a named break instead. In other words, turn:
+
+```nim
+
+block:
+  a()
+  if cond:
+    break
+  b()
+
+```
+
+Into:
+
+```nim
+
+block maybePerformB:
+  a()
+  if cond:
+    break maybePerformB
+  b()
+
+```
+
+### Strict funcs
+
+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 expressitivity. The following code used to be
+accepted:
+
+```nim
+
+{.experimental: "strictFuncs".}
+
+type Node = ref object
+  s: string
+
+func create(s: string): Node =
+  result = Node()
+  result.s = s # store to result[]
+
+```
+
+Now it has to be rewritten to:
+
+```nim
+
+{.experimental: "strictFuncs".}
+
+type Node = ref object
+  s: string
+
+func create(s: string): Node =
+  result = Node(s: s)
+
+```
+
+### Standard library
+
+Several standard library modules have been moved to nimble packages, use `nimble` or `atlas` to install them:
+
+- `std/punycode` => `punycode`
+- `std/asyncftpclient` => `asyncftpclient`
+- `std/smtp` => `smtp`
+- `std/db_common` => `db_connector/db_common`
+- `std/db_sqlite` => `db_connector/db_sqlite`
+- `std/db_mysql` => `db_connector/db_mysql`
+- `std/db_postgres` => `db_connector/db_postgres`
+- `std/db_odbc` => `db_connector/db_odbc`
+- `std/md5` => `checksums/md5`
+- `std/sha1` => `checksums/sha1`
+- `std/sums` => `sums`

changelogs/changelog_2_0_0_details.md

@@ -0,0 +1,560 @@
+# v2.0.0 - 2023-08-01
+
+
+## Changes affecting backward compatibility
+
+- ORC is now the default memory management strategy. Use
+  `--mm:refc` for a transition period.
+
+- The `threads:on` option is now the default.
+
+- `httpclient.contentLength` default to `-1` if the Content-Length header is not set in the response. It follows Apache's `HttpClient` (Java), `http` (go) and .NET `HttpWebResponse` (C#) behaviors. Previously it raised a `ValueError`.
+
+- `addr` is now available for all addressable locations,
+  `unsafeAddr` is now deprecated and an alias for `addr`.
+
+- Certain definitions from the default `system` module have been moved to
+  the following new modules:
+
+  - `std/syncio`
+  - `std/assertions`
+  - `std/formatfloat`
+  - `std/objectdollar`
+  - `std/widestrs`
+  - `std/typedthreads`
+  - `std/sysatomics`
+
+  In the future, these definitions will be removed from the `system` module,
+  and their respective modules will have to be imported to use them.
+  Currently, to make these imports required, the `-d:nimPreviewSlimSystem` option
+  may be used.
+
+- Enabling `-d:nimPreviewSlimSystem` also removes the following deprecated
+  symbols in the `system` module:
+  - Aliases with an `Error` suffix to exception types that have a `Defect` suffix
+    (see [exceptions](https://nim-lang.github.io/Nim/exceptions.html)):
+    `ArithmeticError`, `DivByZeroError`, `OverflowError`,
+    `AccessViolationError`, `AssertionError`, `OutOfMemError`, `IndexError`,
+    `FieldError`, `RangeError`, `StackOverflowError`, `ReraiseError`,
+    `ObjectAssignmentError`, `ObjectConversionError`, `FloatingPointError`,
+    `FloatOverflowError`, `FloatUnderflowError`, `FloatInexactError`,
+    `DeadThreadError`, `NilAccessError`
+  - `addQuitProc`, replaced by `exitprocs.addExitProc`
+  - Legacy unsigned conversion operations: `ze`, `ze64`, `toU8`, `toU16`, `toU32`
+  - `TaintedString`, formerly a distinct alias to `string`
+  - `PInt32`, `PInt64`, `PFloat32`, `PFloat64`, aliases to
+    `ptr int32`, `ptr int64`, `ptr float32`, `ptr float64`
+
+- Enabling `-d:nimPreviewSlimSystem` removes the import of `channels_builtin` in
+  in the `system` module, which is replaced by [threading/channels](https://github.com/nim-lang/threading/blob/master/threading/channels.nim). Use the command `nimble install threading` and import `threading/channels`.
+
+- Enabling `-d:nimPreviewCstringConversion` causes `ptr char`, `ptr array[N, char]` and `ptr UncheckedArray[N, char]` to not support conversion to `cstring` anymore.
+
+- Enabling `-d:nimPreviewProcConversion` causes `proc` to not support conversion to
+  `pointer` anymore. `cast` may be used instead.
+
+- The `gc:v2` option is removed.
+
+- The `mainmodule` and `m` options are removed.
+
+- Optional parameters in combination with `: body` syntax ([RFC #405](https://github.com/nim-lang/RFCs/issues/405))
+  are now opt-in via `experimental:flexibleOptionalParams`.
+
+- Automatic dereferencing (experimental feature) is removed.
+
+- The `Math.trunc` polyfill for targeting Internet Explorer was
+  previously included in most JavaScript output files.
+  Now, it is only included with `-d:nimJsMathTruncPolyfill`.
+  If you are targeting Internet Explorer, you may choose to enable this option
+  or define your own `Math.trunc` polyfill using the [`emit` pragma](https://nim-lang.org/docs/manual.html#implementation-specific-pragmas-emit-pragma).
+  Nim uses `Math.trunc` for the division and modulo operators for integers.
+
+- `shallowCopy` and `shallow` are removed for ARC/ORC. Use `move` when possible or combine assignment and
+`sink` for optimization purposes.
+
+- The experimental `nimPreviewDotLikeOps` switch is going to be removed or deprecated because it didn't fulfill its promises.
+
+- The `{.this.}` pragma, deprecated since 0.19, has been removed.
+- `nil` literals can no longer be directly assigned to variables or fields of `distinct` pointer types. They must be converted instead.
+  ```nim
+  type Foo = distinct ptr int
+
+  # Before:
+  var x: Foo = nil
+  # After:
+  var x: Foo = Foo(nil)
+  ```
+- Removed two type pragma syntaxes deprecated since 0.20, namely
+  `type Foo = object {.final.}`, and `type Foo {.final.} [T] = object`. Instead,
+  use `type Foo[T] {.final.} = object`.
+
+- `foo a = b` now means `foo(a = b)` rather than `foo(a) = b`. This is consistent
+  with the existing behavior of `foo a, b = c` meaning `foo(a, b = c)`.
+  This decision was made with the assumption that the old syntax was used rarely;
+  if your code used the old syntax, please be aware of this change.
+
+- [Overloadable enums](https://nim-lang.github.io/Nim/manual.html#overloadable-enum-value-names) and Unicode Operators
+  are no longer experimental.
+
+- `macros.getImpl` for `const` symbols now returns the full definition node
+  (as `nnkConstDef`) rather than the AST of the constant value.
+
+- Lock levels are deprecated, now a noop.
+
+- `strictEffects` are no longer experimental.
+  Use `legacy:laxEffects` to keep backward compatibility.
+
+- The `gorge`/`staticExec` calls will now return a descriptive message in the output
+  if the execution fails for whatever reason. To get back legacy behaviour, use `-d:nimLegacyGorgeErrors`.
+
+- Pointer to `cstring` conversions now trigger a `[PtrToCstringConv]` warning.
+  This warning will become an error in future versions! Use a `cast` operation
+  like `cast[cstring](x)` instead.
+
+- `logging` will default to flushing all log level messages. To get the legacy behaviour of only flushing Error and Fatal messages, use `-d:nimV1LogFlushBehavior`.
+
+- Redefining templates with the same signature was previously
+  allowed to support certain macro code. To do this explicitly, the
+  `{.redefine.}` pragma has been added. Note that this is only for templates.
+  Implicit redefinition of templates is now deprecated and will give an error in the future.
+
+- Using an unnamed break in a block is deprecated. This warning will become an error in future versions! Use a named block with a named break instead.
+
+- Several Standard libraries have been moved to nimble packages, use `nimble` to install them:
+  - `std/punycode` => `punycode`
+  - `std/asyncftpclient` => `asyncftpclient`
+  - `std/smtp` => `smtp`
+  - `std/db_common` => `db_connector/db_common`
+  - `std/db_sqlite` => `db_connector/db_sqlite`
+  - `std/db_mysql` => `db_connector/db_mysql`
+  - `std/db_postgres` => `db_connector/db_postgres`
+  - `std/db_odbc` => `db_connector/db_odbc`
+  - `std/md5` => `checksums/md5`
+  - `std/sha1` => `checksums/sha1`
+  - `std/sums` => `std/sums`
+
+- Previously, calls like `foo(a, b): ...` or `foo(a, b) do: ...` where the final argument of
+  `foo` had type `proc ()` were assumed by the compiler to mean `foo(a, b, proc () = ...)`.
+  This behavior is now deprecated. Use `foo(a, b) do (): ...` or `foo(a, b, proc () = ...)` instead.
+
+- When `--warning[BareExcept]:on` is enabled, if an `except` specifies no exception or any exception not inheriting from `Defect` or `CatchableError`, a `warnBareExcept` warning will be triggered. For example, the following code will emit a warning:
+  ```nim
+  try:
+    discard
+  except: # Warning: The bare except clause is deprecated; use `except CatchableError:` instead [BareExcept]
+    discard
+  ```
+
+- The experimental `strictFuncs` feature now disallows a store to the heap via a `ref` or `ptr` indirection.
+
+- The underscore identifier (`_`) is now generally not added to scope when
+  used as the name of a definition. While this was already the case for
+  variables, it is now also the case for routine parameters, generic
+  parameters, routine declarations, type declarations, etc. This means that the following code now does not compile:
+
+  ```nim
+  proc foo(_: int): int = _ + 1
+  echo foo(1)
+
+  proc foo[_](t: typedesc[_]): seq[_] = @[default(_)]
+  echo foo[int]()
+
+  proc _() = echo "_"
+  _()
+
+  type _ = int
+  let x: _ = 3
+  ```
+
+  Whereas the following code now compiles:
+
+  ```nim
+  proc foo(_, _: int): int = 123
+  echo foo(1, 2)
+
+  proc foo[_, _](): int = 123
+  echo foo[int, bool]()
+
+  proc foo[T, U](_: typedesc[T], _: typedesc[U]): (T, U) = (default(T), default(U))
+  echo foo(int, bool)
+
+  proc _() = echo "one"
+  proc _() = echo "two"
+
+  type _ = int
+  type _ = float
+  ```
+
+- Added the `--legacy:verboseTypeMismatch` switch to get legacy type mismatch error messages.
+
+- The JavaScript backend now uses [BigInt](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt)
+  for 64-bit integer types (`int64` and `uint64`) by default. As this affects
+  JS code generation, code using these types to interface with the JS backend
+  may need to be updated. Note that `int` and `uint` are not affected.
+
+  For compatibility with [platforms that do not support BigInt](https://caniuse.com/bigint)
+  and in the case of potential bugs with the new implementation, the
+  old behavior is currently still supported with the command line option
+  `--jsbigint64:off`.
+
+- The `proc` and `iterator` type classes now respectively only match
+  procs and iterators. Previously both type classes matched any of
+  procs or iterators.
+
+  ```nim
+  proc prc(): int =
+    123
+
+  iterator iter(): int {.closure.} =
+    yield 123
+
+  proc takesProc[T: proc](x: T) = discard
+  proc takesIter[T: iterator](x: T) = discard
+
+  # always compiled:
+  takesProc(prc)
+  takesIter(iter)
+  # no longer compiles:
+  takesProc(iter)
+  takesIter(prc)
+  ```
+
+- The `proc` and `iterator` type classes now accept a calling convention pragma
+  (i.e. `proc {.closure.}`) that must be shared by matching proc or iterator
+  types. Previously, pragmas were parsed but discarded if no parameter list
+  was given.
+
+  This is represented in the AST by an `nnkProcTy`/`nnkIteratorTy` node with
+  an `nnkEmpty` node in the place of the `nnkFormalParams` node, and the pragma
+  node in the same place as in a concrete `proc` or `iterator` type node. This
+  state of the AST may be unexpected to existing code, both due to the
+  replacement of the `nnkFormalParams` node as well as having child nodes
+  unlike other type class AST.
+
+- Signed integer literals in `set` literals now default to a range type of
+  `0..255` instead of `0..65535` (the maximum size of sets).
+
+- `case` statements with `else` branches put before `elif`/`of` branches in macros
+  are rejected with "invalid order of case branches".
+
+- Destructors now default to `.raises: []` (i.e. destructors must not raise
+  unlisted exceptions) and explicitly raising destructors are implementation
+  defined behavior.
+
+- The very old, undocumented `deprecated` pragma statement syntax for
+  deprecated aliases is now a no-op. The regular deprecated pragma syntax is
+  generally sufficient instead.
+
+  ```nim
+  # now does nothing:
+  {.deprecated: [OldName: NewName].}
+
+  # instead use:
+  type OldName* {.deprecated: "use NewName instead".} = NewName
+  const oldName* {.deprecated: "use newName instead".} = newName
+  ```
+
+  `defined(nimalias)` can be used to check for versions when this syntax was
+  available; however since code that used this syntax is usually very old,
+  these deprecated aliases are likely not used anymore and it may make sense
+  to simply remove these statements.
+
+- `getProgramResult` and `setProgramResult` in `std/exitprocs` are no longer
+  declared when they are not available on the backend. Previously it would call
+  `doAssert false` at runtime despite the condition being checkable at compile-time.
+
+- Custom destructors now supports non-var parameters, e.g. ``proc `=destroy`[T: object](x: T)`` is valid. ``proc `=destroy`[T: object](x: var T)`` is deprecated.
+
+- Relative imports will not resolve to searched paths anymore, e.g. `import ./tables` now reports an error properly.
+
+## Standard library additions and changes
+
+[//]: # "Changes:"
+- OpenSSL 3 is now supported.
+- `macros.parseExpr` and `macros.parseStmt` now accept an optional
+  `filename` argument for more informative errors.
+- The `colors` module is expanded with missing colors from the CSS color standard.
+  `colPaleVioletRed` and `colMediumPurple` have also been changed to match the CSS color standard.
+- Fixed `lists.SinglyLinkedList` being broken after removing the last node ([#19353](https://github.com/nim-lang/Nim/pull/19353)).
+- The `md5` module now works at compile time and in JavaScript.
+- Changed `mimedb` to use an `OrderedTable` instead of `OrderedTableRef`, to support `const` tables.
+- `strutils.find` now uses and defaults to `last = -1` for whole string searches,
+  making limiting it to just the first char (`last = 0`) valid.
+- `strutils.split` and `strutils.rsplit` now return the source string as a single element for an empty separator.
+- `random.rand` now works with `Ordinal`s.
+- Undeprecated `os.isvalidfilename`.
+- `std/oids` now uses `int64` to store time internally (before, it was int32).
+- `std/uri.Uri` dollar (`$`) improved, precalculates the `string` result length from the `Uri`.
+- `std/uri.Uri.isIpv6` is now exported.
+- `std/logging.ConsoleLogger` and `FileLogger` now have a `flushThreshold` attribute to set what log message levels are automatically flushed. For Nim v1 use `-d:nimFlushAllLogs` to automatically flush all message levels. Flushing all logs is the default behavior for Nim v2.
+
+
+- `std/jsfetch.newFetchOptions` now has default values for all parameters.
+- `std/jsformdata` now accepts the `Blob` data type.
+
+- `std/sharedlist` and `std/sharedtables` are now deprecated, see [RFC #433](https://github.com/nim-lang/RFCs/issues/433).
+
+- There is a new compile flag (`-d:nimNoGetRandom`) when building `std/sysrand` to remove the dependency on the Linux `getrandom` syscall.
+
+  This compile flag only affects Linux builds and is necessary if either compiling on a Linux kernel version < 3.17, or if code built will be executing on kernel < 3.17.
+
+  On Linux kernels < 3.17 (such as kernel 3.10 in RHEL7 and CentOS7), the `getrandom` syscall was not yet introduced. Without this, the `std/sysrand` module will not build properly, and if code is built on a kernel >= 3.17 without the flag, any usage of the `std/sysrand` module will fail to execute on a kernel < 3.17 (since it attempts to perform a syscall to `getrandom`, which isn't present in the current kernel). A compile flag has been added to force the `std/sysrand` module to use /dev/urandom (available since Linux kernel 1.3.30), rather than the `getrandom` syscall. This allows for use of a cryptographically secure PRNG, regardless of kernel support for the `getrandom` syscall.
+
+  When building for RHEL7/CentOS7 for example, the entire build process for nim from a source package would then be:
+  ```sh
+  $ yum install devtoolset-8 # Install GCC version 8 vs the standard 4.8.5 on RHEL7/CentOS7. Alternatively use -d:nimEmulateOverflowChecks. See issue #13692 for details
+  $ scl enable devtoolset-8 bash # Run bash shell with default toolchain of gcc 8
+  $ sh build.sh  # per unix install instructions
+  $ bin/nim c koch  # per unix install instructions
+  $ ./koch boot -d:release  # per unix install instructions
+  $ ./koch tools -d:nimNoGetRandom  # pass the nimNoGetRandom flag to compile std/sysrand without support for getrandom syscall
+  ```
+
+  This is necessary to pass when building Nim on kernel versions < 3.17 in particular to avoid an error of "SYS_getrandom undeclared" during the build process for the stdlib (`sysrand` in particular).
+
+[//]: # "Additions:"
+- Added ISO 8601 week date utilities in `times`:
+  - Added `IsoWeekRange`, a range type for weeks in a week-based year.
+  - Added `IsoYear`, a distinct type for a week-based year in contrast to a regular year.
+  - Added an `initDateTime` overload to create a `DateTime` from an ISO week date.
+  - Added `getIsoWeekAndYear` to get an ISO week number and week-based year from a datetime.
+  - Added `getIsoWeeksInYear` to return the number of weeks in a week-based year.
+- Added new modules which were previously part of `std/os`:
+  - Added `std/oserrors` for OS error reporting.
+  - Added `std/envvars` for environment variables handling.
+  - Added `std/cmdline` for reading command line parameters.
+  - Added `std/paths`, `std/dirs`, `std/files`, `std/symlinks` and `std/appdirs`.
+- Added `sep` parameter in `std/uri` to specify the query separator.
+- Added `UppercaseLetters`, `LowercaseLetters`, `PunctuationChars`, `PrintableChars` sets to `std/strutils`.
+- Added `complex.sgn` for obtaining the phase of complex numbers.
+- Added `insertAdjacentText`, `insertAdjacentElement`, `insertAdjacentHTML`,
+  `after`, `before`, `closest`, `append`, `hasAttributeNS`, `removeAttributeNS`,
+  `hasPointerCapture`, `releasePointerCapture`, `requestPointerLock`,
+  `replaceChildren`, `replaceWith`, `scrollIntoViewIfNeeded`, `setHTML`,
+  `toggleAttribute`, and `matches` to `std/dom`.
+- Added [`jsre.hasIndices`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/hasIndices).
+- Added `capacity` for `string` and `seq` to return the current capacity, see [RFC #460](https://github.com/nim-lang/RFCs/issues/460).
+- Added `openArray[char]` overloads for `std/parseutils` and `std/unicode`, allowing for more code reuse.
+- Added a `safe` parameter to `base64.encodeMime`.
+- Added `parseutils.parseSize` - inverse to `strutils.formatSize` - to parse human readable sizes.
+- Added `minmax` to `sequtils`, as a more efficient `(min(_), max(_))` over sequences.
+- `std/jscore` for the JavaScript target:
+  + Added bindings to [`Array.shift`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/shift)
+  and [`queueMicrotask`](https://developer.mozilla.org/en-US/docs/Web/API/queueMicrotask).
+  + Added `toDateString`, `toISOString`, `toJSON`, `toTimeString`, `toUTCString` converters for `DateTime`.
+- Added `BackwardsIndex` overload for `CacheSeq`.
+- Added support for nested `with` blocks in `std/with`.
+- Added `ensureMove` to the system module. It ensures that the passed argument is moved, otherwise an error is given at the compile time.
+
+
+[//]: # "Deprecations:"
+- Deprecated `selfExe` for Nimscript.
+- Deprecated `std/base64.encode` for collections of arbitrary integer element type.
+  Now only `byte` and `char` are supported.
+
+[//]: # "Removals:"
+- Removed deprecated module `parseopt2`.
+- Removed deprecated module `sharedstrings`.
+- Removed deprecated module `dom_extensions`.
+- Removed deprecated module `LockFreeHash`.
+- Removed deprecated module `events`.
+- Removed deprecated `oids.oidToString`.
+- Removed define `nimExperimentalAsyncjsThen` for `std/asyncjs.then` and `std/jsfetch`.
+- Removed deprecated `jsre.test` and `jsre.toString`.
+- Removed deprecated `math.c_frexp`.
+- Removed deprecated `` httpcore.`==` ``.
+- Removed deprecated `std/posix.CMSG_SPACE` and `std/posix.CMSG_LEN` that take wrong argument types.
+- Removed deprecated `osproc.poDemon`, symbol with typo.
+- Removed deprecated `tables.rightSize`.
+
+
+- Removed deprecated `posix.CLONE_STOPPED`.
+
+
+## Language changes
+
+- [Tag tracking](https://nim-lang.github.io/Nim/manual.html#effect-system-tag-tracking) now supports the definition of forbidden tags by the `.forbids` pragma
+  which can be used to disable certain effects in proc types.
+- [Case statement macros](https://nim-lang.github.io/Nim/manual.html#macros-case-statement-macros) are no longer experimental,
+  meaning you no longer need to enable the experimental switch `caseStmtMacros` to use them.
+- Full command syntax and block arguments i.e. `foo a, b: c` are now allowed
+  for the right-hand side of type definitions in type sections. Previously
+  they would error with "invalid indentation".
+
+- Compile-time define changes:
+  - `defined` now accepts identifiers separated by dots, i.e. `defined(a.b.c)`.
+    In the command line, this is defined as `-d:a.b.c`. Older versions can
+    use backticks as in ``defined(`a.b.c`)`` to access such defines.
+  - [Define pragmas for constants](https://nim-lang.github.io/Nim/manual.html#implementation-specific-pragmas-compileminustime-define-pragmas)
+    now support a string argument for qualified define names.
+
+    ```nim
+    # -d:package.FooBar=42
+    const FooBar {.intdefine: "package.FooBar".}: int = 5
+    echo FooBar # 42
+    ```
+
+    This was added to help disambiguate similar define names for different packages.
+    In older versions, this could only be achieved with something like the following:
+
+    ```nim
+    const FooBar = block:
+      const `package.FooBar` {.intdefine.}: int = 5
+      `package.FooBar`
+    ```
+  - A generic `define` pragma for constants has been added that interprets
+    the value of the define based on the type of the constant value.
+    See the [experimental manual](https://nim-lang.github.io/Nim/manual_experimental.html#generic-nimdefine-pragma)
+    for a list of supported types.
+
+- [Macro pragmas](https://nim-lang.github.io/Nim/manual.html#userminusdefined-pragmas-macro-pragmas) changes:
+  - Templates now accept macro pragmas.
+  - Macro pragmas for var/let/const sections have been redesigned in a way that works
+    similarly to routine macro pragmas. The new behavior is documented in the
+    [experimental manual](https://nim-lang.github.io/Nim/manual_experimental.html#extended-macro-pragmas).
+  - Pragma macros on type definitions can now return `nnkTypeSection` nodes as well as `nnkTypeDef`,
+    allowing multiple type definitions to be injected in place of the original type definition.
+
+    ```nim
+    import macros
+
+    macro multiply(amount: static int, s: untyped): untyped =
+      let name = $s[0].basename
+      result = newNimNode(nnkTypeSection)
+      for i in 1 .. amount:
+        result.add(newTree(nnkTypeDef, ident(name & $i), s[1], s[2]))
+
+    type
+      Foo = object
+      Bar {.multiply: 3.} = object
+        x, y, z: int
+      Baz = object
+    # becomes
+    type
+      Foo = object
+      Bar1 = object
+        x, y, z: int
+      Bar2 = object
+        x, y, z: int
+      Bar3 = object
+        x, y, z: int
+      Baz = object
+    ```
+
+- A new form of type inference called [top-down inference](https://nim-lang.github.io/Nim/manual_experimental.html#topminusdown-type-inference)
+  has been implemented for a variety of basic cases. For example, code like the following now compiles:
+
+  ```nim
+  let foo: seq[(float, byte, cstring)] = @[(1, 2, "abc")]
+  ```
+
+- `cstring` is now accepted as a selector in `case` statements, removing the
+  need to convert to `string`. On the JS backend, this is translated directly
+  to a `switch` statement.
+
+- Nim now supports `out` parameters and ["strict definitions"](https://nim-lang.github.io/Nim/manual_experimental.html#strict-definitions-and-nimout-parameters).
+- Nim now offers a [strict mode](https://nim-lang.github.io/Nim/manual_experimental.html#strict-case-objects) for `case objects`.
+
+- IBM Z architecture and macOS m1 arm64 architecture are supported.
+
+- `=wasMoved` can now be overridden by users.
+
+- There is a new pragma called [quirky](https://nim-lang.github.io/Nim/manual_experimental.html#quirky-routines) that can be used to affect the code
+  generation of goto based exception handling. It can improve the produced code size but its effects can be subtle so use it with care.
+
+- Tuple unpacking for variables is now treated as syntax sugar that directly
+  expands into multiple assignments. Along with this, tuple unpacking for
+  variables can now be nested.
+
+  ```nim
+  proc returnsNestedTuple(): (int, (int, int), int, int) = (4, (5, 7), 2, 3)
+
+  let (x, (_, y), _, z) = returnsNestedTuple()
+  # roughly becomes
+  let
+    tmpTup1 = returnsNestedTuple()
+    x = tmpTup1[0]
+    tmpTup2 = tmpTup1[1]
+    y = tmpTup2[1]
+    z = tmpTup1[3]
+  ```
+
+  As a result `nnkVarTuple` nodes in variable sections will no longer be
+  reflected in `typed` AST.
+
+- C++ interoperability:
+  - New [`virtual`](https://nim-lang.github.io/Nim/manual_experimental.html#virtual-pragma) pragma added.
+  - Improvements to [`constructor`](https://nim-lang.github.io/Nim/manual_experimental.html#constructor-pragma) pragma.
+
+## Compiler changes
+
+- The `gc` switch has been renamed to `mm` ("memory management") in order to reflect the
+  reality better. (Nim moved away from all techniques based on "tracing".)
+
+- Defines the `gcRefc` symbol which allows writing specific code for the refc GC.
+
+- `nim` can now compile version 1.4.0 as follows: `nim c --lib:lib --stylecheck:off compiler/nim`,
+  without requiring `-d:nimVersion140` which is now a noop.
+
+- `--styleCheck`, `--hintAsError` and `--warningAsError` now only apply to the current package.
+
+- The switch `--nimMainPrefix:prefix` has been added to add a prefix to the names of `NimMain` and
+  related functions produced on the backend. This prevents conflicts with other Nim
+  static libraries.
+
+- When compiling for release, the flag `-fno-math-errno` is used for GCC.
+- Removed deprecated `LineTooLong` hint.
+- Line numbers and file names of source files work correctly inside templates for JavaScript targets.
+
+- Removed support for LCC (Local C), Pelles C, Digital Mars and Watcom compilers.
+
+
+## Docgen
+
+- `Markdown` is now the default markup language of doc comments (instead
+  of the legacy `RstMarkdown` mode). In this release we begin to separate
+  RST and Markdown features to better follow specification of each
+  language, with the focus on Markdown development.
+  See also [the docs](https://nim-lang.github.io/Nim/markdown_rst.html).
+
+  * Added a `{.doctype: Markdown | RST | RstMarkdown.}` pragma allowing to
+    select the markup language mode in the doc comments of the current `.nim`
+    file for processing by `nim doc`:
+
+      1. `Markdown` (default) is basically CommonMark (standard Markdown) +
+         some Pandoc Markdown features + some RST features that are missing
+         in our current implementation of CommonMark and Pandoc Markdown.
+      2. `RST` closely follows the RST spec with few additional Nim features.
+      3. `RstMarkdown` is a maximum mix of RST and Markdown features, which
+          is kept for the sake of compatibility and ease of migration.
+
+  * Added separate `md2html` and `rst2html` commands for processing
+    standalone `.md` and `.rst` files respectively (and also `md2tex`/`rst2tex`).
+
+- Added Pandoc Markdown bracket syntax `[...]` for making anchor-less links.
+- Docgen now supports concise syntax for referencing Nim symbols:
+  instead of specifying HTML anchors directly one can use original
+  Nim symbol declarations (adding the aforementioned link brackets
+  `[...]` around them).
+    * To use this feature across modules, a new `importdoc` directive was added.
+      Using this feature for referencing also helps to ensure that links
+      (inside one module or the whole project) are not broken.
+- Added support for RST & Markdown quote blocks (blocks starting with `>`).
+- Added a popular Markdown definition lists extension.
+- Added Markdown indented code blocks (blocks indented by >= 4 spaces).
+- Added syntax for additional parameters to Markdown code blocks:
+
+       ```nim test="nim c $1"
+       ...
+       ```
+
+## Tool changes
+
+- Nim now ships Nimble version 0.14 which added support for lock-files. Libraries are stored in `$nimbleDir/pkgs2` (it was `$nimbleDir/pkgs` before). Use `nimble develop --global` to create an old style link file in the special links directory documented at https://github.com/nim-lang/nimble#nimble-develop.
+- nimgrep added the option `--inContext` (and `--notInContext`), which
+  allows to filter only matches with the context block containing a given pattern.
+- nimgrep: names of options containing "include/exclude" are deprecated,
+  e.g. instead of `--includeFile` and `--excludeFile` we have
+  `--filename` and `--notFilename` respectively.
+  Also the semantics are now consistent for such positive/negative filters.
+- koch now supports the `--skipIntegrityCheck` option. The command `koch --skipIntegrityCheck boot -d:release` always builds the compiler twice.

changelogs/changelog_2_2_0.md

@@ -0,0 +1,12 @@
+# v2.2.0 - 2023-mm-dd
+
+## Changes affecting backward compatibility
+
+## Standard library additions and changes
+
+## Language changes
+
+## Compiler changes
+
+## Tool changes
+

ci/action.nim

@@ -3,7 +3,7 @@ import std/[strutils, os, osproc, parseutils, strformat]
 
 proc main() =
   var msg = ""
-  const cmd = "./koch boot --gc:orc -d:release"
+  const cmd = "./koch boot --mm:orc -d:release"
 
   let (output, exitCode) = execCmdEx(cmd)
 

ci/funs.sh

@@ -58,7 +58,11 @@ _nimNumCpu(){
   # FreeBSD | macOS: $(sysctl -n hw.ncpu)
   # OpenBSD: $(sysctl -n hw.ncpuonline)
   # windows: $NUMBER_OF_PROCESSORS ?
-  echo $(nproc 2>/dev/null || sysctl -n hw.logicalcpu 2>/dev/null || getconf _NPROCESSORS_ONLN 2>/dev/null || 1)
+  if env | grep -q '^NIMCORES='; then
+    echo $NIMCORES
+  else
+    echo $(nproc 2>/dev/null || sysctl -n hw.logicalcpu 2>/dev/null || getconf _NPROCESSORS_ONLN 2>/dev/null || 1)
+  fi
 }
 
 _nimBuildCsourcesIfNeeded(){

compiler/aliasanalysis.nim

@@ -74,7 +74,7 @@ proc aliases*(obj, field: PNode): AliasKind =
   # x[i] -> x[i]: maybe; Further analysis could make this return true when i is a runtime-constant
   # x[i] -> x[j]: maybe; also returns maybe if only one of i or j is a compiletime-constant
   template collectImportantNodes(result, n) =
-    var result: seq[PNode]
+    var result: seq[PNode] = @[]
     var n = n
     while true:
       case n.kind

compiler/aliases.nim

@@ -10,7 +10,9 @@
 ## Simple alias analysis for the HLO and the code generators.
 
 import
-  ast, astalgo, types, trees, intsets
+  ast, astalgo, types, trees
+
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -49,14 +51,16 @@ proc isPartOfAux(a, b: PType, marker: var IntSet): TAnalysisResult =
   if compareTypes(a, b, dcEqIgnoreDistinct): return arYes
   case a.kind
   of tyObject:
-    if a[0] != nil:
-      result = isPartOfAux(a[0].skipTypes(skipPtrs), b, marker)
+    if a.baseClass != nil:
+      result = isPartOfAux(a.baseClass.skipTypes(skipPtrs), b, marker)
     if result == arNo: result = isPartOfAux(a.n, b, marker)
   of tyGenericInst, tyDistinct, tyAlias, tySink:
-    result = isPartOfAux(lastSon(a), b, marker)
-  of tyArray, tySet, tyTuple:
-    for i in 0..<a.len:
-      result = isPartOfAux(a[i], b, marker)
+    result = isPartOfAux(skipModifier(a), b, marker)
+  of tySet, tyArray:
+    result = isPartOfAux(a.elementType, b, marker)
+  of tyTuple:
+    for aa in a.kids:
+      result = isPartOfAux(aa, b, marker)
       if result == arYes: return
   else: discard
 
@@ -114,6 +118,8 @@ proc isPartOf*(a, b: PNode): TAnalysisResult =
         # use expensive type check:
         if isPartOf(a.sym.typ, b.sym.typ) != arNo:
           result = arMaybe
+        else:
+          result = arNo
     of nkBracketExpr:
       result = isPartOf(a[0], b[0])
       if a.len >= 2 and b.len >= 2:
@@ -149,7 +155,7 @@ proc isPartOf*(a, b: PNode): TAnalysisResult =
       result = isPartOf(a[1], b[1])
     of nkObjUpConv, nkObjDownConv, nkCheckedFieldExpr:
       result = isPartOf(a[0], b[0])
-    else: discard
+    else: result = arNo
     # Calls return a new location, so a default of ``arNo`` is fine.
   else:
     # go down recursively; this is quite demanding:
@@ -165,6 +171,7 @@ proc isPartOf*(a, b: PNode): TAnalysisResult =
 
     of DerefKinds:
       # a* !<| b[] iff
+      result = arNo
       if isPartOf(a.typ, b.typ) != arNo:
         result = isPartOf(a, b[0])
         if result == arNo: result = arMaybe
@@ -186,7 +193,9 @@ proc isPartOf*(a, b: PNode): TAnalysisResult =
         if isPartOf(a.typ, b.typ) != arNo:
           result = isPartOf(a[0], b)
           if result == arNo: result = arMaybe
-      else: discard
+        else:
+          result = arNo
+      else: result = arNo
     of nkObjConstr:
       result = arNo
       for i in 1..<b.len:
@@ -204,4 +213,6 @@ proc isPartOf*(a, b: PNode): TAnalysisResult =
     of nkBracket:
       if b.len > 0:
         result = isPartOf(a, b[0])
-    else: discard
+      else:
+        result = arNo
+    else: result = arNo

compiler/astalgo.nim

@@ -12,23 +12,18 @@
 # the data structures here are used in various places of the compiler.
 
 import
-  ast, hashes, intsets, options, lineinfos, ropes, idents, rodutils,
+  ast, astyaml, options, lineinfos, idents, rodutils,
   msgs
 
-import strutils except addf
+import std/[hashes, intsets]
+import std/strutils except addf
+
+export astyaml.treeToYaml, astyaml.typeToYaml, astyaml.symToYaml, astyaml.lineInfoToStr
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
 proc hashNode*(p: RootRef): Hash
-proc treeToYaml*(conf: ConfigRef; n: PNode, indent: int = 0, maxRecDepth: int = - 1): Rope
-  # Convert a tree into its YAML representation; this is used by the
-  # YAML code generator and it is invaluable for debugging purposes.
-  # If maxRecDepht <> -1 then it won't print the whole graph.
-proc typeToYaml*(conf: ConfigRef; n: PType, indent: int = 0, maxRecDepth: int = - 1): Rope
-proc symToYaml*(conf: ConfigRef; n: PSym, indent: int = 0, maxRecDepth: int = - 1): Rope
-proc lineInfoToStr*(conf: ConfigRef; info: TLineInfo): Rope
-
 
 # these are for debugging only: They are not really deprecated, but I want
 # the warning so that release versions do not contain debugging statements:
@@ -36,15 +31,6 @@ proc debug*(n: PSym; conf: ConfigRef = nil) {.exportc: "debugSym", deprecated.}
 proc debug*(n: PType; conf: ConfigRef = nil) {.exportc: "debugType", deprecated.}
 proc debug*(n: PNode; conf: ConfigRef = nil) {.exportc: "debugNode", deprecated.}
 
-proc typekinds*(t: PType) {.deprecated.} =
-  var t = t
-  var s = ""
-  while t != nil and t.len > 0:
-    s.add $t.kind
-    s.add " "
-    t = t.lastSon
-  echo s
-
 template debug*(x: PSym|PType|PNode) {.deprecated.} =
   when compiles(c.config):
     debug(c.config, x)
@@ -79,16 +65,6 @@ template mdbg*: bool {.deprecated.} =
   else:
     error()
 
-# --------------------------- ident tables ----------------------------------
-proc idTableGet*(t: TIdTable, key: PIdObj): RootRef
-proc idTableGet*(t: TIdTable, key: int): RootRef
-proc idTablePut*(t: var TIdTable, key: PIdObj, val: RootRef)
-proc idTableHasObjectAsKey*(t: TIdTable, key: PIdObj): bool
-  # checks if `t` contains the `key` (compared by the pointer value, not only
-  # `key`'s id)
-proc idNodeTableGet*(t: TIdNodeTable, key: PIdObj): PNode
-proc idNodeTablePut*(t: var TIdNodeTable, key: PIdObj, val: PNode)
-
 # ---------------------------------------------------------------------------
 
 proc lookupInRecord*(n: PNode, field: PIdent): PSym
@@ -109,7 +85,7 @@ type
     data*: TIIPairSeq
 
 
-proc initIiTable*(x: var TIITable)
+proc initIITable*(x: var TIITable)
 proc iiTableGet*(t: TIITable, key: int): int
 proc iiTablePut*(t: var TIITable, key, val: int)
 
@@ -197,6 +173,7 @@ proc getSymFromList*(list: PNode, ident: PIdent, start: int = 0): PSym =
   result = nil
 
 proc sameIgnoreBacktickGensymInfo(a, b: string): bool =
+  result = false
   if a[0] != b[0]: return false
   var alen = a.len - 1
   while alen > 0 and a[alen] != '`': dec(alen)
@@ -226,10 +203,11 @@ proc getNamedParamFromList*(list: PNode, ident: PIdent): PSym =
   ## Named parameters are special because a named parameter can be
   ## gensym'ed and then they have '\`<number>' suffix that we need to
   ## ignore, see compiler / evaltempl.nim, snippet:
-  ##   ```
+  ##   ```nim
   ##   result.add newIdentNode(getIdent(c.ic, x.name.s & "\`gensym" & $x.id),
   ##            if c.instLines: actual.info else: templ.info)
   ##   ```
+  result = nil
   for i in 1..<list.len:
     let it = list[i].sym
     if it.name.id == ident.id or
@@ -242,169 +220,7 @@ proc mustRehash(length, counter: int): bool =
   assert(length > counter)
   result = (length * 2 < counter * 3) or (length - counter < 4)
 
-proc rspaces(x: int): Rope =
-  # returns x spaces
-  result = rope(spaces(x))
-
-proc toYamlChar(c: char): string =
-  case c
-  of '\0'..'\x1F', '\x7F'..'\xFF': result = "\\u" & strutils.toHex(ord(c), 4)
-  of '\'', '\"', '\\': result = '\\' & c
-  else: result = $c
-
-proc makeYamlString*(s: string): Rope =
-  # We have to split long strings into many ropes. Otherwise
-  # this could trigger InternalError(111). See the ropes module for
-  # further information.
-  const MaxLineLength = 64
-  result = ""
-  var res = "\""
-  for i in 0..<s.len:
-    if (i + 1) mod MaxLineLength == 0:
-      res.add('\"')
-      res.add("\n")
-      result.add(rope(res))
-      res = "\""              # reset
-    res.add(toYamlChar(s[i]))
-  res.add('\"')
-  result.add(rope(res))
-
-proc flagsToStr[T](flags: set[T]): Rope =
-  if flags == {}:
-    result = rope("[]")
-  else:
-    result = ""
-    for x in items(flags):
-      if result != "": result.add(", ")
-      result.add(makeYamlString($x))
-    result = "[" & result & "]"
-
-proc lineInfoToStr(conf: ConfigRef; info: TLineInfo): Rope =
-  result = "[$1, $2, $3]" % [makeYamlString(toFilename(conf, info)),
-                             rope(toLinenumber(info)),
-                             rope(toColumn(info))]
-
-proc treeToYamlAux(conf: ConfigRef; n: PNode, marker: var IntSet,
-                   indent, maxRecDepth: int): Rope
-proc symToYamlAux(conf: ConfigRef; n: PSym, marker: var IntSet,
-                  indent, maxRecDepth: int): Rope
-proc typeToYamlAux(conf: ConfigRef; n: PType, marker: var IntSet,
-                   indent, maxRecDepth: int): Rope
-
-proc symToYamlAux(conf: ConfigRef; n: PSym, marker: var IntSet, indent: int,
-                  maxRecDepth: int): Rope =
-  if n == nil:
-    result = rope("null")
-  elif containsOrIncl(marker, n.id):
-    result = "\"$1\"" % [rope(n.name.s)]
-  else:
-    var ast = treeToYamlAux(conf, n.ast, marker, indent + 2, maxRecDepth - 1)
-                                 #rope("typ"), typeToYamlAux(conf, n.typ, marker,
-                                 #  indent + 2, maxRecDepth - 1),
-    let istr = rspaces(indent + 2)
-    result = rope("{")
-    result.addf("$N$1\"kind\": $2", [istr, makeYamlString($n.kind)])
-    result.addf("$N$1\"name\": $2", [istr, makeYamlString(n.name.s)])
-    result.addf("$N$1\"typ\": $2", [istr, typeToYamlAux(conf, n.typ, marker, indent + 2, maxRecDepth - 1)])
-    if conf != nil:
-      # if we don't pass the config, we probably don't care about the line info
-      result.addf("$N$1\"info\": $2", [istr, lineInfoToStr(conf, n.info)])
-    if card(n.flags) > 0:
-      result.addf("$N$1\"flags\": $2", [istr, flagsToStr(n.flags)])
-    result.addf("$N$1\"magic\": $2", [istr, makeYamlString($n.magic)])
-    result.addf("$N$1\"ast\": $2", [istr, ast])
-    result.addf("$N$1\"options\": $2", [istr, flagsToStr(n.options)])
-    result.addf("$N$1\"position\": $2", [istr, rope(n.position)])
-    result.addf("$N$1\"k\": $2", [istr, makeYamlString($n.loc.k)])
-    result.addf("$N$1\"storage\": $2", [istr, makeYamlString($n.loc.storage)])
-    if card(n.loc.flags) > 0:
-      result.addf("$N$1\"flags\": $2", [istr, makeYamlString($n.loc.flags)])
-    result.addf("$N$1\"r\": $2", [istr, n.loc.r])
-    result.addf("$N$1\"lode\": $2", [istr, treeToYamlAux(conf, n.loc.lode, marker, indent + 2, maxRecDepth - 1)])
-    result.addf("$N$1}", [rspaces(indent)])
-
-proc typeToYamlAux(conf: ConfigRef; n: PType, marker: var IntSet, indent: int,
-                   maxRecDepth: int): Rope =
-  var sonsRope: Rope
-  if n == nil:
-    sonsRope = rope("null")
-  elif containsOrIncl(marker, n.id):
-    sonsRope = "\"$1 @$2\"" % [rope($n.kind), rope(
-        strutils.toHex(cast[int](n), sizeof(n) * 2))]
-  else:
-    if n.len > 0:
-      sonsRope = rope("[")
-      for i in 0..<n.len:
-        if i > 0: sonsRope.add(",")
-        sonsRope.addf("$N$1$2", [rspaces(indent + 4), typeToYamlAux(conf, n[i],
-            marker, indent + 4, maxRecDepth - 1)])
-      sonsRope.addf("$N$1]", [rspaces(indent + 2)])
-    else:
-      sonsRope = rope("null")
-
-    let istr = rspaces(indent + 2)
-    result = rope("{")
-    result.addf("$N$1\"kind\": $2", [istr, makeYamlString($n.kind)])
-    result.addf("$N$1\"sym\": $2",  [istr, symToYamlAux(conf, n.sym, marker, indent + 2, maxRecDepth - 1)])
-    result.addf("$N$1\"n\": $2",     [istr, treeToYamlAux(conf, n.n, marker, indent + 2, maxRecDepth - 1)])
-    if card(n.flags) > 0:
-      result.addf("$N$1\"flags\": $2", [istr, flagsToStr(n.flags)])
-    result.addf("$N$1\"callconv\": $2", [istr, makeYamlString($n.callConv)])
-    result.addf("$N$1\"size\": $2", [istr, rope(n.size)])
-    result.addf("$N$1\"align\": $2", [istr, rope(n.align)])
-    result.addf("$N$1\"sons\": $2", [istr, sonsRope])
-
-proc treeToYamlAux(conf: ConfigRef; n: PNode, marker: var IntSet, indent: int,
-                   maxRecDepth: int): Rope =
-  if n == nil:
-    result = rope("null")
-  else:
-    var istr = rspaces(indent + 2)
-    result = "{$N$1\"kind\": $2" % [istr, makeYamlString($n.kind)]
-    if maxRecDepth != 0:
-      if conf != nil:
-        result.addf(",$N$1\"info\": $2", [istr, lineInfoToStr(conf, n.info)])
-      case n.kind
-      of nkCharLit..nkInt64Lit:
-        result.addf(",$N$1\"intVal\": $2", [istr, rope(n.intVal)])
-      of nkFloatLit, nkFloat32Lit, nkFloat64Lit:
-        result.addf(",$N$1\"floatVal\": $2",
-            [istr, rope(n.floatVal.toStrMaxPrecision)])
-      of nkStrLit..nkTripleStrLit:
-        result.addf(",$N$1\"strVal\": $2", [istr, makeYamlString(n.strVal)])
-      of nkSym:
-        result.addf(",$N$1\"sym\": $2",
-             [istr, symToYamlAux(conf, n.sym, marker, indent + 2, maxRecDepth)])
-      of nkIdent:
-        if n.ident != nil:
-          result.addf(",$N$1\"ident\": $2", [istr, makeYamlString(n.ident.s)])
-        else:
-          result.addf(",$N$1\"ident\": null", [istr])
-      else:
-        if n.len > 0:
-          result.addf(",$N$1\"sons\": [", [istr])
-          for i in 0..<n.len:
-            if i > 0: result.add(",")
-            result.addf("$N$1$2", [rspaces(indent + 4), treeToYamlAux(conf, n[i],
-                marker, indent + 4, maxRecDepth - 1)])
-          result.addf("$N$1]", [istr])
-      result.addf(",$N$1\"typ\": $2",
-           [istr, typeToYamlAux(conf, n.typ, marker, indent + 2, maxRecDepth)])
-    result.addf("$N$1}", [rspaces(indent)])
-
-proc treeToYaml(conf: ConfigRef; n: PNode, indent: int = 0, maxRecDepth: int = - 1): Rope =
-  var marker = initIntSet()
-  result = treeToYamlAux(conf, n, marker, indent, maxRecDepth)
-
-proc typeToYaml(conf: ConfigRef; n: PType, indent: int = 0, maxRecDepth: int = - 1): Rope =
-  var marker = initIntSet()
-  result = typeToYamlAux(conf, n, marker, indent, maxRecDepth)
-
-proc symToYaml(conf: ConfigRef; n: PSym, indent: int = 0, maxRecDepth: int = - 1): Rope =
-  var marker = initIntSet()
-  result = symToYamlAux(conf, n, marker, indent, maxRecDepth)
-
-import tables
+import std/tables
 
 const backrefStyle = "\e[90m"
 const enumStyle = "\e[34m"
@@ -568,14 +384,12 @@ proc value(this: var DebugPrinter; value: PType) =
     this.key "n"
     this.value value.n
 
-  if value.len > 0:
-    this.key "sons"
-    this.openBracket
-    for i in 0..<value.len:
-      this.value value[i]
-      if i != value.len - 1:
-        this.comma
-    this.closeBracket
+  this.key "sons"
+  this.openBracket
+  for i, a in value.ikids:
+    if i > 0: this.comma
+    this.value a
+  this.closeBracket
 
   if value.n != nil:
     this.key "n"
@@ -644,30 +458,33 @@ proc value(this: var DebugPrinter; value: PNode) =
 
 
 proc debug(n: PSym; conf: ConfigRef) =
-  var this: DebugPrinter
-  this.visited = initTable[pointer, int]()
-  this.renderSymType = true
-  this.useColor = not defined(windows)
+  var this = DebugPrinter(
+    visited: initTable[pointer, int](),
+    renderSymType: true,
+    useColor: not defined(windows)
+  )
   this.value(n)
   echo($this.res)
 
 proc debug(n: PType; conf: ConfigRef) =
-  var this: DebugPrinter
-  this.visited = initTable[pointer, int]()
-  this.renderSymType = true
-  this.useColor = not defined(windows)
+  var this = DebugPrinter(
+    visited: initTable[pointer, int](),
+    renderSymType: true,
+    useColor: not defined(windows)
+  )
   this.value(n)
   echo($this.res)
 
 proc debug(n: PNode; conf: ConfigRef) =
-  var this: DebugPrinter
-  this.visited = initTable[pointer, int]()
-  #this.renderSymType = true
-  this.useColor = not defined(windows)
+  var this = DebugPrinter(
+    visited: initTable[pointer, int](),
+    renderSymType: false,
+    useColor: not defined(windows)
+  )
   this.value(n)
   echo($this.res)
 
-proc nextTry(h, maxHash: Hash): Hash =
+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
@@ -890,125 +707,12 @@ proc initTabIter*(ti: var TTabIter, tab: TStrTable): PSym =
     result = nextIter(ti, tab)
 
 iterator items*(tab: TStrTable): PSym =
-  var it: TTabIter
+  var it: TTabIter = default(TTabIter)
   var s = initTabIter(it, tab)
   while s != nil:
     yield s
     s = nextIter(it, tab)
 
-proc hasEmptySlot(data: TIdPairSeq): bool =
-  for h in 0..high(data):
-    if data[h].key == nil:
-      return true
-  result = false
-
-proc idTableRawGet(t: TIdTable, key: int): int =
-  var h: Hash
-  h = key and high(t.data)    # start with real hash value
-  while t.data[h].key != nil:
-    if t.data[h].key.id == key:
-      return h
-    h = nextTry(h, high(t.data))
-  result = - 1
-
-proc idTableHasObjectAsKey(t: TIdTable, key: PIdObj): bool =
-  var index = idTableRawGet(t, key.id)
-  if index >= 0: result = t.data[index].key == key
-  else: result = false
-
-proc idTableGet(t: TIdTable, key: PIdObj): RootRef =
-  var index = idTableRawGet(t, key.id)
-  if index >= 0: result = t.data[index].val
-  else: result = nil
-
-proc idTableGet(t: TIdTable, key: int): RootRef =
-  var index = idTableRawGet(t, key)
-  if index >= 0: result = t.data[index].val
-  else: result = nil
-
-iterator pairs*(t: TIdTable): tuple[key: int, value: RootRef] =
-  for i in 0..high(t.data):
-    if t.data[i].key != nil:
-      yield (t.data[i].key.id, t.data[i].val)
-
-proc idTableRawInsert(data: var TIdPairSeq, key: PIdObj, val: RootRef) =
-  var h: Hash
-  h = key.id and high(data)
-  while data[h].key != nil:
-    assert(data[h].key.id != key.id)
-    h = nextTry(h, high(data))
-  assert(data[h].key == nil)
-  data[h].key = key
-  data[h].val = val
-
-proc idTablePut(t: var TIdTable, key: PIdObj, val: RootRef) =
-  var
-    index: int
-    n: TIdPairSeq
-  index = idTableRawGet(t, key.id)
-  if index >= 0:
-    assert(t.data[index].key != nil)
-    t.data[index].val = val
-  else:
-    if mustRehash(t.data.len, t.counter):
-      newSeq(n, t.data.len * GrowthFactor)
-      for i in 0..high(t.data):
-        if t.data[i].key != nil:
-          idTableRawInsert(n, t.data[i].key, t.data[i].val)
-      assert(hasEmptySlot(n))
-      swap(t.data, n)
-    idTableRawInsert(t.data, key, val)
-    inc(t.counter)
-
-iterator idTablePairs*(t: TIdTable): tuple[key: PIdObj, val: RootRef] =
-  for i in 0..high(t.data):
-    if not isNil(t.data[i].key): yield (t.data[i].key, t.data[i].val)
-
-proc idNodeTableRawGet(t: TIdNodeTable, key: PIdObj): int =
-  var h: Hash
-  h = key.id and high(t.data) # start with real hash value
-  while t.data[h].key != nil:
-    if t.data[h].key.id == key.id:
-      return h
-    h = nextTry(h, high(t.data))
-  result = - 1
-
-proc idNodeTableGet(t: TIdNodeTable, key: PIdObj): PNode =
-  var index: int
-  index = idNodeTableRawGet(t, key)
-  if index >= 0: result = t.data[index].val
-  else: result = nil
-
-proc idNodeTableRawInsert(data: var TIdNodePairSeq, key: PIdObj, val: PNode) =
-  var h: Hash
-  h = key.id and high(data)
-  while data[h].key != nil:
-    assert(data[h].key.id != key.id)
-    h = nextTry(h, high(data))
-  assert(data[h].key == nil)
-  data[h].key = key
-  data[h].val = val
-
-proc idNodeTablePut(t: var TIdNodeTable, key: PIdObj, val: PNode) =
-  var index = idNodeTableRawGet(t, key)
-  if index >= 0:
-    assert(t.data[index].key != nil)
-    t.data[index].val = val
-  else:
-    if mustRehash(t.data.len, t.counter):
-      var n: TIdNodePairSeq
-      newSeq(n, t.data.len * GrowthFactor)
-      for i in 0..high(t.data):
-        if t.data[i].key != nil:
-          idNodeTableRawInsert(n, t.data[i].key, t.data[i].val)
-      swap(t.data, n)
-    idNodeTableRawInsert(t.data, key, val)
-    inc(t.counter)
-
-iterator pairs*(t: TIdNodeTable): tuple[key: PIdObj, val: PNode] =
-  for i in 0..high(t.data):
-    if not isNil(t.data[i].key): yield (t.data[i].key, t.data[i].val)
-
 proc initIITable(x: var TIITable) =
   x.counter = 0
   newSeq(x.data, StartSize)
@@ -1054,15 +758,8 @@ proc iiTablePut(t: var TIITable, key, val: int) =
     iiTableRawInsert(t.data, key, val)
     inc(t.counter)
 
-proc isAddrNode*(n: PNode): bool =
-  case n.kind
-    of nkAddr, nkHiddenAddr: true
-    of nkCallKinds:
-      if n[0].kind == nkSym and n[0].sym.magic == mAddr: true
-      else: false
-    else: false
-
 proc listSymbolNames*(symbols: openArray[PSym]): string =
+  result = ""
   for sym in symbols:
     if result.len > 0:
       result.add ", "

compiler/astmsgs.nim

@@ -5,7 +5,7 @@ import options, ast, msgs
 proc typSym*(t: PType): PSym =
   result = t.sym
   if result == nil and t.kind == tyGenericInst: # this might need to be refined
-    result = t[0].sym
+    result = t.genericHead.sym
 
 proc addDeclaredLoc*(result: var string, conf: ConfigRef; sym: PSym) =
   result.add " [$1 declared in $2]" % [sym.kind.toHumanStr, toFileLineCol(conf, sym.info)]
@@ -24,6 +24,12 @@ proc addDeclaredLoc*(result: var string, conf: ConfigRef; typ: PType) =
     result.add " declared in " & toFileLineCol(conf, typ.sym.info)
   result.add "]"
 
+proc addTypeNodeDeclaredLoc*(result: var string, conf: ConfigRef; typ: PType) =
+  result.add " [$1" % typ.kind.toHumanStr
+  if typ.sym != nil:
+    result.add " declared in " & toFileLineCol(conf, typ.sym.info)
+  result.add "]"
+
 proc addDeclaredLocMaybe*(result: var string, conf: ConfigRef; typ: PType) =
   if optDeclaredLocs in conf.globalOptions: addDeclaredLoc(result, conf, typ)
 

compiler/astyaml.nim

@@ -0,0 +1,154 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2012 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# AST YAML printing
+
+import "."/[ast, lineinfos, msgs, options, rodutils]
+import std/[intsets, strutils]
+
+proc addYamlString*(res: var string; s: string) =
+  res.add "\""
+  for c in s:
+    case c
+    of '\0' .. '\x1F', '\x7F' .. '\xFF':
+      res.add("\\u" & strutils.toHex(ord(c), 4))
+    of '\"', '\\':
+      res.add '\\' & c
+    else:
+      res.add c
+
+  res.add('\"')
+
+proc makeYamlString(s: string): string =
+  result = ""
+  result.addYamlString(s)
+
+proc flagsToStr[T](flags: set[T]): string =
+  if flags == {}:
+    result = "[]"
+  else:
+    result = ""
+    for x in items(flags):
+      if result != "":
+        result.add(", ")
+      result.addYamlString($x)
+    result = "[" & result & "]"
+
+proc lineInfoToStr*(conf: ConfigRef; info: TLineInfo): string =
+  result = "["
+  result.addYamlString(toFilename(conf, info))
+  result.addf ", $1, $2]", [toLinenumber(info), toColumn(info)]
+
+proc treeToYamlAux(res: var string; conf: ConfigRef; n: PNode; marker: var IntSet; indent, maxRecDepth: int)
+proc symToYamlAux(res: var string; conf: ConfigRef; n: PSym; marker: var IntSet; indent, maxRecDepth: int)
+proc typeToYamlAux(res: var string; conf: ConfigRef; n: PType; marker: var IntSet; indent, maxRecDepth: int)
+
+proc symToYamlAux(res: var string; conf: ConfigRef; n: PSym; marker: var IntSet; indent: int; maxRecDepth: int) =
+  if n == nil:
+    res.add("null")
+  elif containsOrIncl(marker, n.id):
+    res.addYamlString(n.name.s)
+  else:
+    let istr = spaces(indent * 4)
+
+    res.addf("kind: $1", [makeYamlString($n.kind)])
+    res.addf("\n$1name: $2", [istr, makeYamlString(n.name.s)])
+    res.addf("\n$1typ: ", [istr])
+    res.typeToYamlAux(conf, n.typ, marker, indent + 1, maxRecDepth - 1)
+    if conf != nil:
+      # if we don't pass the config, we probably don't care about the line info
+      res.addf("\n$1info: $2", [istr, lineInfoToStr(conf, n.info)])
+    if card(n.flags) > 0:
+      res.addf("\n$1flags: $2", [istr, flagsToStr(n.flags)])
+    res.addf("\n$1magic: $2", [istr, makeYamlString($n.magic)])
+    res.addf("\n$1ast: ", [istr])
+    res.treeToYamlAux(conf, n.ast, marker, indent + 1, maxRecDepth - 1)
+    res.addf("\n$1options: $2", [istr, flagsToStr(n.options)])
+    res.addf("\n$1position: $2", [istr, $n.position])
+    res.addf("\n$1k: $2", [istr, makeYamlString($n.loc.k)])
+    res.addf("\n$1storage: $2", [istr, makeYamlString($n.loc.storage)])
+    if card(n.loc.flags) > 0:
+      res.addf("\n$1flags: $2", [istr, makeYamlString($n.loc.flags)])
+    res.addf("\n$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; indent: int; maxRecDepth: int) =
+  if n == nil:
+    res.add("null")
+  elif containsOrIncl(marker, n.id):
+    res.addf "\"$1 @$2\"" % [$n.kind, strutils.toHex(cast[uint](n), sizeof(n) * 2)]
+  else:
+    let istr = spaces(indent * 4)
+    res.addf("kind: $2", [istr, makeYamlString($n.kind)])
+    res.addf("\n$1sym: ")
+    res.symToYamlAux(conf, n.sym, marker, indent + 1, maxRecDepth - 1)
+    res.addf("\n$1n: ")
+    res.treeToYamlAux(conf, n.n, marker, indent + 1, maxRecDepth - 1)
+    if card(n.flags) > 0:
+      res.addf("\n$1flags: $2", [istr, flagsToStr(n.flags)])
+    res.addf("\n$1callconv: $2", [istr, makeYamlString($n.callConv)])
+    res.addf("\n$1size: $2", [istr, $(n.size)])
+    res.addf("\n$1align: $2", [istr, $(n.align)])
+    if n.hasElementType:
+      res.addf("\n$1sons:")
+      for a in n.kids:
+        res.addf("\n  - ")
+        res.typeToYamlAux(conf, a, marker, indent + 1, maxRecDepth - 1)
+
+proc treeToYamlAux(res: var string; conf: ConfigRef; n: PNode; marker: var IntSet; indent: int;
+                   maxRecDepth: int) =
+  if n == nil:
+    res.add("null")
+  else:
+    var istr = spaces(indent * 4)
+    res.addf("kind: $1" % [makeYamlString($n.kind)])
+
+    if maxRecDepth != 0:
+      if conf != nil:
+        res.addf("\n$1info: $2", [istr, lineInfoToStr(conf, n.info)])
+      case n.kind
+      of nkCharLit .. nkInt64Lit:
+        res.addf("\n$1intVal: $2", [istr, $(n.intVal)])
+      of nkFloatLit, nkFloat32Lit, nkFloat64Lit:
+        res.addf("\n$1floatVal: $2", [istr, n.floatVal.toStrMaxPrecision])
+      of nkStrLit .. nkTripleStrLit:
+        res.addf("\n$1strVal: $2", [istr, makeYamlString(n.strVal)])
+      of nkSym:
+        res.addf("\n$1sym: ", [istr])
+        res.symToYamlAux(conf, n.sym, marker, indent + 1, maxRecDepth)
+      of nkIdent:
+        if n.ident != nil:
+          res.addf("\n$1ident: $2", [istr, makeYamlString(n.ident.s)])
+        else:
+          res.addf("\n$1ident: null", [istr])
+      else:
+        if n.len > 0:
+          res.addf("\n$1sons: ", [istr])
+          for i in 0 ..< n.len:
+            res.addf("\n$1  - ", [istr])
+            res.treeToYamlAux(conf, n[i], marker, indent + 1, maxRecDepth - 1)
+      if n.typ != nil:
+        res.addf("\n$1typ: ", [istr])
+        res.typeToYamlAux(conf, n.typ, marker, indent + 1, maxRecDepth)
+
+proc treeToYaml*(conf: ConfigRef; n: PNode; indent: int = 0; maxRecDepth: int = -1): string =
+  var marker = initIntSet()
+  result = newStringOfCap(1024)
+  result.treeToYamlAux(conf, n, marker, indent, maxRecDepth)
+
+proc typeToYaml*(conf: ConfigRef; n: PType; indent: int = 0; maxRecDepth: int = -1): string =
+  var marker = initIntSet()
+  result = newStringOfCap(1024)
+  result.typeToYamlAux(conf, n, marker, indent, maxRecDepth)
+
+proc symToYaml*(conf: ConfigRef; n: PSym; indent: int = 0; maxRecDepth: int = -1): string =
+  var marker = initIntSet()
+  result = newStringOfCap(1024)
+  result.symToYamlAux(conf, n, marker, indent, maxRecDepth)

compiler/bitsets.nim

@@ -87,5 +87,11 @@ const populationCount: array[uint8, uint8] = block:
     arr
 
 proc bitSetCard*(x: TBitSet): BiggestInt =
+  result = 0
   for it in x:
     result.inc int(populationCount[it])
+
+proc bitSetToWord*(s: TBitSet; size: int): BiggestUInt =
+  result = 0
+  for j in 0..<size:
+    if j < s.len: result = result or (BiggestUInt(s[j]) shl (j * 8))

compiler/btrees.nim

@@ -38,6 +38,7 @@ template less(a, b): bool = cmp(a, b) < 0
 template eq(a, b): bool = cmp(a, b) == 0
 
 proc getOrDefault*[Key, Val](b: BTree[Key, Val], key: Key): Val =
+  result = default(Val)
   var x = b.root
   while x.isInternal:
     for j in 0..<x.entries:
@@ -68,7 +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):
+      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])
@@ -91,7 +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):
+      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])

compiler/ccgcalls.nim

@@ -24,6 +24,7 @@ proc canRaiseDisp(p: BProc; n: PNode): bool =
 
 proc preventNrvo(p: BProc; dest, le, ri: PNode): bool =
   proc locationEscapes(p: BProc; le: PNode; inTryStmt: bool): bool =
+    result = false
     var n = le
     while true:
       # do NOT follow nkHiddenDeref here!
@@ -46,6 +47,7 @@ proc preventNrvo(p: BProc; dest, le, ri: PNode): bool =
         # cannot analyse the location; assume the worst
         return true
 
+  result = false
   if le != nil:
     for i in 1..<ri.len:
       let r = ri[i]
@@ -74,6 +76,23 @@ proc isHarmlessStore(p: BProc; canRaise: bool; d: TLoc): bool =
   else:
     result = false
 
+proc cleanupTemp(p: BProc; returnType: PType, tmp: TLoc): bool =
+  if returnType.kind in {tyVar, tyLent}:
+    # we don't need to worry about var/lent return types
+    result = false
+  elif hasDestructor(returnType) and getAttachedOp(p.module.g.graph, returnType, attachedDestructor) != nil:
+    let dtor = getAttachedOp(p.module.g.graph, returnType, attachedDestructor)
+    var op = initLocExpr(p, newSymNode(dtor))
+    var callee = rdLoc(op)
+    let destroy = if dtor.typ.firstParamType.kind == tyVar:
+        callee & "(&" & rdLoc(tmp) & ")"
+      else:
+        callee & "(" & rdLoc(tmp) & ")"
+    raiseExitCleanup(p, destroy)
+    result = true
+  else:
+    result = false
+
 proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
                callee, params: Rope) =
   let canRaise = p.config.exc == excGoto and canRaiseDisp(p, ri[0])
@@ -81,13 +100,17 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
   var pl = callee & "(" & params
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
-  if typ[0] != nil:
+  if typ.returnType != nil:
+    var flags: TAssignmentFlags = {}
+    if typ.returnType.kind in {tyOpenArray, tyVarargs}:
+      # perhaps generate no temp if the call doesn't have side effects
+      flags.incl needTempForOpenArray
     if isInvalidReturnType(p.config, typ):
       if params.len != 0: pl.add(", ")
       # beware of 'result = p(result)'. We may need to allocate a temporary:
       if d.k in {locTemp, locNone} or not preventNrvo(p, d.lode, le, ri):
         # Great, we can use 'd':
-        if d.k == locNone: getTemp(p, typ[0], d, needsInit=true)
+        if d.k == locNone: d = getTemp(p, typ.returnType, needsInit=true)
         elif d.k notin {locTemp} and not hasNoInit(ri):
           # reset before pass as 'result' var:
           discard "resetLoc(p, d)"
@@ -95,8 +118,7 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
         pl.add(");\n")
         line(p, cpsStmts, pl)
       else:
-        var tmp: TLoc
-        getTemp(p, typ[0], tmp, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ.returnType, needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         pl.add(");\n")
         line(p, cpsStmts, pl)
@@ -114,31 +136,34 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
           excl d.flags, lfSingleUse
         else:
           if d.k == locNone and p.splitDecls == 0:
-            getTempCpp(p, typ[0], d, pl)
+            d = getTempCpp(p, typ.returnType, pl)
           else:
-            if d.k == locNone: getTemp(p, typ[0], d)
-            var list: TLoc
-            initLoc(list, locCall, d.lode, OnUnknown)
+            if d.k == locNone: d = getTemp(p, typ.returnType)
+            var list = initLoc(locCall, d.lode, OnUnknown)
             list.r = pl
             genAssignment(p, d, list, {}) # no need for deep copying
             if canRaise: raiseExit(p)
 
       elif isHarmlessStore(p, canRaise, d):
-        if d.k == locNone: getTemp(p, typ[0], d)
+        var useTemp = false
+        if d.k == locNone:
+          useTemp = true
+          d = getTemp(p, typ.returnType)
         assert(d.t != nil)        # generate an assignment to d:
-        var list: TLoc
-        initLoc(list, locCall, d.lode, OnUnknown)
+        var list = initLoc(locCall, d.lode, OnUnknown)
         list.r = pl
-        genAssignment(p, d, list, {}) # no need for deep copying
-        if canRaise: raiseExit(p)
+        genAssignment(p, d, list, flags) # no need for deep copying
+        if canRaise:
+          if not (useTemp and cleanupTemp(p, typ.returnType, d)):
+            raiseExit(p)
       else:
-        var tmp: TLoc
-        getTemp(p, typ[0], tmp, needsInit=true)
-        var list: TLoc
-        initLoc(list, locCall, d.lode, OnUnknown)
+        var tmp: TLoc = getTemp(p, typ.returnType, needsInit=true)
+        var list = initLoc(locCall, d.lode, OnUnknown)
         list.r = pl
-        genAssignment(p, tmp, list, {}) # no need for deep copying
-        if canRaise: raiseExit(p)
+        genAssignment(p, tmp, list, flags) # no need for deep copying
+        if canRaise:
+          if not cleanupTemp(p, typ.returnType, tmp):
+            raiseExit(p)
         genAssignment(p, d, tmp, {})
   else:
     pl.add(");\n")
@@ -149,24 +174,32 @@ proc genBoundsCheck(p: BProc; arr, a, b: TLoc)
 
 proc reifiedOpenArray(n: PNode): bool {.inline.} =
   var x = n
-  while x.kind in {nkAddr, nkHiddenAddr, nkHiddenStdConv, nkHiddenDeref}:
-    x = x[0]
+  while true:
+    case x.kind
+    of {nkAddr, nkHiddenAddr, nkHiddenDeref}:
+      x = x[0]
+    of nkHiddenStdConv:
+      x = x[1]
+    else:
+      break
   if x.kind == nkSym and x.sym.kind == skParam:
     result = false
   else:
     result = true
 
 proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareForMutation = false): (Rope, Rope) =
-  var a, b, c: TLoc
-  initLocExpr(p, q[1], a)
-  initLocExpr(p, q[2], b)
-  initLocExpr(p, q[3], c)
+  var a = initLocExpr(p, q[1])
+  var b = initLocExpr(p, q[2])
+  var c = initLocExpr(p, q[3])
   # but first produce the required index checks:
   if optBoundsCheck in p.options:
     genBoundsCheck(p, a, b, c)
   if prepareForMutation:
     linefmt(p, cpsStmts, "#nimPrepareStrMutationV2($1);$n", [byRefLoc(p, a)])
-  let ty = skipTypes(a.t, abstractVar+{tyPtr})
+  # bug #23321: In the function mapType, ptrs (tyPtr, tyVar, tyLent, tyRef)
+  # are mapped into ctPtrToArray, the dereference of which is skipped
+  # in the `genref`. We need to skip these ptrs here
+  let ty = skipTypes(a.t, abstractVar+{tyPtr, tyRef})
   let dest = getTypeDesc(p.module, destType)
   let lengthExpr = "($1)-($2)+1" % [rdLoc(c), rdLoc(b)]
   case ty.kind
@@ -205,6 +238,7 @@ proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareF
                   [rdLoc(a), rdLoc(b), dataField(p), dest, dataFieldAccessor(p, rdLoc(a))],
                 lengthExpr)
   else:
+    result = ("", "")
     internalError(p.config, "openArrayLoc: " & typeToString(a.t))
 
 proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
@@ -221,11 +255,10 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
         for i in 0..<q.len-1:
           genStmts(p, q[i])
         q = q.lastSon
-    let (x, y) = genOpenArraySlice(p, q, formalType, n.typ[0])
+    let (x, y) = genOpenArraySlice(p, q, formalType, n.typ.elementType)
     result.add x & ", " & y
   else:
-    var a: TLoc
-    initLocExpr(p, if n.kind == nkHiddenStdConv: n[1] else: n, a)
+    var a = initLocExpr(p, if n.kind == nkHiddenStdConv: n[1] else: n)
     case skipTypes(a.t, abstractVar+{tyStatic}).kind
     of tyOpenArray, tyVarargs:
       if reifiedOpenArray(n):
@@ -241,8 +274,7 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
           optSeqDestructors in p.config.globalOptions:
         linefmt(p, cpsStmts, "#nimPrepareStrMutationV2($1);$n", [byRefLoc(p, a)])
       if ntyp.kind in {tyVar} and not compileToCpp(p.module):
-        var t: TLoc
-        t.r = "(*$1)" % [a.rdLoc]
+        var t = TLoc(r: "(*$1)" % [a.rdLoc])
         result.add "($4) ? ((*$1)$3) : NIM_NIL, $2" %
                      [a.rdLoc, lenExpr(p, t), dataField(p),
                       dataFieldAccessor(p, "*" & a.rdLoc)]
@@ -252,15 +284,14 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
     of tyArray:
       result.add "$1, $2" % [rdLoc(a), rope(lengthOrd(p.config, a.t))]
     of tyPtr, tyRef:
-      case lastSon(a.t).kind
+      case elementType(a.t).kind
       of tyString, tySequence:
-        var t: TLoc
-        t.r = "(*$1)" % [a.rdLoc]
+        var t = TLoc(r: "(*$1)" % [a.rdLoc])
         result.add "($4) ? ((*$1)$3) : NIM_NIL, $2" %
                      [a.rdLoc, lenExpr(p, t), dataField(p),
                       dataFieldAccessor(p, "*" & a.rdLoc)]
       of tyArray:
-        result.add "$1, $2" % [rdLoc(a), rope(lengthOrd(p.config, lastSon(a.t)))]
+        result.add "$1, $2" % [rdLoc(a), rope(lengthOrd(p.config, elementType(a.t)))]
       else:
         internalError(p.config, "openArrayLoc: " & typeToString(a.t))
     else: internalError(p.config, "openArrayLoc: " & typeToString(a.t))
@@ -269,20 +300,19 @@ proc withTmpIfNeeded(p: BProc, a: TLoc, needsTmp: bool): TLoc =
   # Bug https://github.com/status-im/nimbus-eth2/issues/1549
   # Aliasing is preferred over stack overflows.
   # Also don't regress for non ARC-builds, too risky.
-  if needsTmp and a.lode.typ != nil and p.config.selectedGC in {gcArc, gcOrc} and
+  if needsTmp and a.lode.typ != nil and p.config.selectedGC in {gcArc, gcAtomicArc, gcOrc} and
       getSize(p.config, a.lode.typ) < 1024:
-    getTemp(p, a.lode.typ, result, needsInit=false)
+    result = getTemp(p, a.lode.typ, needsInit=false)
     genAssignment(p, result, a, {})
   else:
     result = a
 
 proc literalsNeedsTmp(p: BProc, a: TLoc): TLoc =
-  getTemp(p, a.lode.typ, result, needsInit=false)
+  result = getTemp(p, a.lode.typ, needsInit=false)
   genAssignment(p, result, a, {})
 
 proc genArgStringToCString(p: BProc, n: PNode; result: var Rope; needsTmp: bool) {.inline.} =
-  var a: TLoc
-  initLocExpr(p, n[0], a)
+  var a = initLocExpr(p, n[0])
   appcg(p.module, result, "#nimToCStringConv($1)", [withTmpIfNeeded(p, a, needsTmp).rdLoc])
 
 proc genArg(p: BProc, n: PNode, param: PSym; call: PNode; result: var Rope; needsTmp = false) =
@@ -292,15 +322,16 @@ proc genArg(p: BProc, n: PNode, param: PSym; call: PNode; result: var Rope; need
   elif skipTypes(param.typ, abstractVar).kind in {tyOpenArray, tyVarargs}:
     var n = if n.kind != nkHiddenAddr: n else: n[0]
     openArrayLoc(p, param.typ, n, result)
-  elif ccgIntroducedPtr(p.config, param, call[0].typ[0]):
-    initLocExpr(p, n, a)
+  elif ccgIntroducedPtr(p.config, param, call[0].typ.returnType) and
+    (optByRef notin param.options or not p.module.compileToCpp):
+    a = initLocExpr(p, n)
     if n.kind in {nkCharLit..nkNilLit}:
       addAddrLoc(p.config, literalsNeedsTmp(p, a), result)
     else:
       addAddrLoc(p.config, withTmpIfNeeded(p, a, needsTmp), result)
   elif p.module.compileToCpp and param.typ.kind in {tyVar} and
       n.kind == nkHiddenAddr:
-    initLocExprSingleUse(p, n[0], a)
+    a = initLocExprSingleUse(p, n[0])
     # if the proc is 'importc'ed but not 'importcpp'ed then 'var T' still
     # means '*T'. See posix.nim for lots of examples that do that in the wild.
     let callee = call[0]
@@ -311,7 +342,12 @@ proc genArg(p: BProc, n: PNode, param: PSym; call: PNode; result: var Rope; need
     else:
       addRdLoc(a, result)
   else:
-    initLocExprSingleUse(p, n, a)
+    a = initLocExprSingleUse(p, n)
+    if param.typ.kind in abstractPtrs:
+      let typ = skipTypes(param.typ, abstractPtrs)
+      if typ.sym != nil and sfImportc in typ.sym.flags:
+        a.r = "(($1) ($2))" %
+          [getTypeDesc(p.module, param.typ), rdCharLoc(a)]
     addRdLoc(withTmpIfNeeded(p, a, needsTmp), result)
   #assert result != nil
 
@@ -320,12 +356,13 @@ proc genArgNoParam(p: BProc, n: PNode; result: var Rope; needsTmp = false) =
   if n.kind == nkStringToCString:
     genArgStringToCString(p, n, result, needsTmp)
   else:
-    initLocExprSingleUse(p, n, a)
+    a = initLocExprSingleUse(p, n)
     addRdLoc(withTmpIfNeeded(p, a, needsTmp), result)
 
 import aliasanalysis
 
 proc potentialAlias(n: PNode, potentialWrites: seq[PNode]): bool =
+  result = false
   for p in potentialWrites:
     if p.aliases(n) != no or n.aliases(p) != no:
       return true
@@ -355,7 +392,7 @@ proc getPotentialWrites(n: PNode; mutate: bool; result: var seq[PNode]) =
   of nkCallKinds:
     case n.getMagic:
     of mIncl, mExcl, mInc, mDec, mAppendStrCh, mAppendStrStr, mAppendSeqElem,
-        mAddr, mNew, mNewFinalize, mWasMoved, mDestroy, mReset:
+        mAddr, mNew, mNewFinalize, mWasMoved, mDestroy:
       getPotentialWrites(n[1], true, result)
       for i in 2..<n.len:
         getPotentialWrites(n[i], mutate, result)
@@ -381,13 +418,13 @@ proc genParams(p: BProc, ri: PNode, typ: PType; result: var Rope) =
   # We must generate temporaries in cases like #14396
   # to keep the strict Left-To-Right evaluation
   var needTmp = newSeq[bool](ri.len - 1)
-  var potentialWrites: seq[PNode]
+  var potentialWrites: seq[PNode] = @[]
   for i in countdown(ri.len - 1, 1):
     if ri[i].skipTrivialIndirections.kind == nkSym:
       needTmp[i - 1] = potentialAlias(ri[i], potentialWrites)
     else:
       #if not ri[i].typ.isCompileTimeOnly:
-      var potentialReads: seq[PNode]
+      var potentialReads: seq[PNode] = @[]
       getPotentialReads(ri[i], potentialReads)
       for n in potentialReads:
         if not needTmp[i - 1]:
@@ -399,7 +436,7 @@ proc genParams(p: BProc, ri: PNode, typ: PType; result: var Rope) =
 
   var oldLen = result.len
   for i in 1..<ri.len:
-    if i < typ.len:
+    if i < typ.n.len:
       assert(typ.n[i].kind == nkSym)
       let paramType = typ.n[i]
       if not paramType.typ.isCompileTimeOnly:
@@ -419,13 +456,11 @@ proc addActualSuffixForHCR(res: var Rope, module: PSym, sym: PSym) =
     res = res & "_actual".rope
 
 proc genPrefixCall(p: BProc, le, ri: PNode, d: var TLoc) =
-  var op: TLoc
   # this is a hotspot in the compiler
-  initLocExpr(p, ri[0], op)
+  var op = initLocExpr(p, ri[0])
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInstOwned)
   assert(typ.kind == tyProc)
-  assert(typ.len == typ.n.len)
 
   var params = newRopeAppender()
   genParams(p, ri, typ, params)
@@ -443,13 +478,11 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
   const PatProc = "$1.ClE_0? $1.ClP_0($3$1.ClE_0):(($4)($1.ClP_0))($2)"
   const PatIter = "$1.ClP_0($3$1.ClE_0)" # we know the env exists
 
-  var op: TLoc
-  initLocExpr(p, ri[0], op)
+  var op = initLocExpr(p, ri[0])
 
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInstOwned)
   assert(typ.kind == tyProc)
-  assert(typ.len == typ.n.len)
 
   var pl = newRopeAppender()
   genParams(p, ri, typ, pl)
@@ -462,14 +495,14 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
 
   let rawProc = getClosureType(p.module, typ, clHalf)
   let canRaise = p.config.exc == excGoto and canRaiseDisp(p, ri[0])
-  if typ[0] != nil:
+  if typ.returnType != nil:
     if isInvalidReturnType(p.config, typ):
       if ri.len > 1: pl.add(", ")
       # beware of 'result = p(result)'. We may need to allocate a temporary:
       if d.k in {locTemp, locNone} or not preventNrvo(p, d.lode, le, ri):
         # Great, we can use 'd':
         if d.k == locNone:
-          getTemp(p, typ[0], d, needsInit=true)
+          d = getTemp(p, typ.returnType, needsInit=true)
         elif d.k notin {locTemp} and not hasNoInit(ri):
           # reset before pass as 'result' var:
           discard "resetLoc(p, d)"
@@ -477,17 +510,15 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
         genCallPattern()
         if canRaise: raiseExit(p)
       else:
-        var tmp: TLoc
-        getTemp(p, typ[0], tmp, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ.returnType, needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         genCallPattern()
         if canRaise: raiseExit(p)
         genAssignment(p, d, tmp, {}) # no need for deep copying
     elif isHarmlessStore(p, canRaise, d):
-      if d.k == locNone: getTemp(p, typ[0], d)
+      if d.k == locNone: d = getTemp(p, typ.returnType)
       assert(d.t != nil)        # generate an assignment to d:
-      var list: TLoc
-      initLoc(list, locCall, d.lode, OnUnknown)
+      var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
       if tfIterator in typ.flags:
         list.r = PatIter % [rdLoc(op), pl, pl.addComma, rawProc]
       else:
@@ -495,11 +526,9 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
       genAssignment(p, d, list, {}) # no need for deep copying
       if canRaise: raiseExit(p)
     else:
-      var tmp: TLoc
-      getTemp(p, typ[0], tmp)
+      var tmp: TLoc = getTemp(p, typ.returnType)
       assert(d.t != nil)        # generate an assignment to d:
-      var list: TLoc
-      initLoc(list, locCall, d.lode, OnUnknown)
+      var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
       if tfIterator in typ.flags:
         list.r = PatIter % [rdLoc(op), pl, pl.addComma, rawProc]
       else:
@@ -513,14 +542,14 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
 
 proc genOtherArg(p: BProc; ri: PNode; i: int; typ: PType; result: var Rope;
                  argsCounter: var int) =
-  if i < typ.len:
+  if i < typ.n.len:
     # 'var T' is 'T&' in C++. This means we ignore the request of
     # any nkHiddenAddr when it's a 'var T'.
     let paramType = typ.n[i]
     assert(paramType.kind == nkSym)
     if paramType.typ.isCompileTimeOnly:
       discard
-    elif typ[i].kind in {tyVar} and ri[i].kind == nkHiddenAddr:
+    elif paramType.typ.kind in {tyVar} and ri[i].kind == nkHiddenAddr:
       if argsCounter > 0: result.add ", "
       genArgNoParam(p, ri[i][0], result)
       inc argsCounter
@@ -595,7 +624,7 @@ proc genThisArg(p: BProc; ri: PNode; i: int; typ: PType; result: var Rope) =
   # for better or worse c2nim translates the 'this' argument to a 'var T'.
   # However manual wrappers may also use 'ptr T'. In any case we support both
   # for convenience.
-  internalAssert p.config, i < typ.len
+  internalAssert p.config, i < typ.n.len
   assert(typ.n[i].kind == nkSym)
   # if the parameter is lying (tyVar) and thus we required an additional deref,
   # skip the deref:
@@ -667,7 +696,7 @@ proc genPatternCall(p: BProc; ri: PNode; pat: string; typ: PType; result: var Ro
       inc j
       inc i
     of '\'':
-      var idx, stars: int
+      var idx, stars: int = 0
       if scanCppGenericSlot(pat, i, idx, stars):
         var t = resolveStarsInCppType(typ, idx, stars)
         if t == nil: result.add("void")
@@ -681,12 +710,10 @@ proc genPatternCall(p: BProc; ri: PNode; pat: string; typ: PType; result: var Ro
         result.add(substr(pat, start, i - 1))
 
 proc genInfixCall(p: BProc, le, ri: PNode, d: var TLoc) =
-  var op: TLoc
-  initLocExpr(p, ri[0], op)
+  var op = initLocExpr(p, ri[0])
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
   assert(typ.kind == tyProc)
-  assert(typ.len == typ.n.len)
   # don't call '$' here for efficiency:
   let pat = $ri[0].sym.loc.r
   internalAssert p.config, pat.len > 0
@@ -695,7 +722,7 @@ proc genInfixCall(p: BProc, le, ri: PNode, d: var TLoc) =
     genPatternCall(p, ri, pat, typ, pl)
     # simpler version of 'fixupCall' that works with the pl+params combination:
     var typ = skipTypes(ri[0].typ, abstractInst)
-    if typ[0] != nil:
+    if typ.returnType != nil:
       if p.module.compileToCpp and lfSingleUse in d.flags:
         # do not generate spurious temporaries for C++! For C we're better off
         # with them to prevent undefined behaviour and because the codegen
@@ -704,10 +731,9 @@ proc genInfixCall(p: BProc, le, ri: PNode, d: var TLoc) =
         d.r = pl
         excl d.flags, lfSingleUse
       else:
-        if d.k == locNone: getTemp(p, typ[0], d)
+        if d.k == locNone: d = getTemp(p, typ.returnType)
         assert(d.t != nil)        # generate an assignment to d:
-        var list: TLoc
-        initLoc(list, locCall, d.lode, OnUnknown)
+        var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
         list.r = pl
         genAssignment(p, d, list, {}) # no need for deep copying
     else:
@@ -721,19 +747,16 @@ proc genInfixCall(p: BProc, le, ri: PNode, d: var TLoc) =
     pl.add(op.r)
     var params = newRopeAppender()
     for i in 2..<ri.len:
-      assert(typ.len == typ.n.len)
       genOtherArg(p, ri, i, typ, params, argsCounter)
     fixupCall(p, le, ri, d, pl, params)
 
 proc genNamedParamCall(p: BProc, ri: PNode, d: var TLoc) =
   # generates a crappy ObjC call
-  var op: TLoc
-  initLocExpr(p, ri[0], op)
+  var op = initLocExpr(p, ri[0])
   var pl = "["
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
   assert(typ.kind == tyProc)
-  assert(typ.len == typ.n.len)
 
   # don't call '$' here for efficiency:
   let pat = $ri[0].sym.loc.r
@@ -755,8 +778,7 @@ proc genNamedParamCall(p: BProc, ri: PNode, d: var TLoc) =
       pl.add(": ")
       genArg(p, ri[2], typ.n[2].sym, ri, pl)
   for i in start..<ri.len:
-    assert(typ.len == typ.n.len)
-    if i >= typ.len:
+    if i >= typ.n.len:
       internalError(p.config, ri.info, "varargs for objective C method?")
     assert(typ.n[i].kind == nkSym)
     var param = typ.n[i].sym
@@ -764,30 +786,28 @@ proc genNamedParamCall(p: BProc, ri: PNode, d: var TLoc) =
     pl.add(param.name.s)
     pl.add(": ")
     genArg(p, ri[i], param, ri, pl)
-  if typ[0] != nil:
+  if typ.returnType != nil:
     if isInvalidReturnType(p.config, typ):
       if ri.len > 1: pl.add(" ")
       # beware of 'result = p(result)'. We always allocate a temporary:
       if d.k in {locTemp, locNone}:
         # We already got a temp. Great, special case it:
-        if d.k == locNone: getTemp(p, typ[0], d, needsInit=true)
+        if d.k == locNone: d = getTemp(p, typ.returnType, needsInit=true)
         pl.add("Result: ")
         pl.add(addrLoc(p.config, d))
         pl.add("];\n")
         line(p, cpsStmts, pl)
       else:
-        var tmp: TLoc
-        getTemp(p, typ[0], tmp, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ.returnType, needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         pl.add("];\n")
         line(p, cpsStmts, pl)
         genAssignment(p, d, tmp, {}) # no need for deep copying
     else:
       pl.add("]")
-      if d.k == locNone: getTemp(p, typ[0], d)
+      if d.k == locNone: d = getTemp(p, typ.returnType)
       assert(d.t != nil)        # generate an assignment to d:
-      var list: TLoc
-      initLoc(list, locCall, ri, OnUnknown)
+      var list: TLoc = initLoc(locCall, ri, OnUnknown)
       list.r = pl
       genAssignment(p, d, list, {}) # no need for deep copying
   else:

compiler/ccgreset.nim

@@ -54,25 +54,23 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
   case typ.kind
   of tyGenericInst, tyGenericBody, tyTypeDesc, tyAlias, tyDistinct, tyInferred,
      tySink, tyOwned:
-    specializeResetT(p, accessor, lastSon(typ))
+    specializeResetT(p, accessor, skipModifier(typ))
   of tyArray:
-    let arraySize = lengthOrd(p.config, typ[0])
-    var i: TLoc
-    getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt), i)
+    let arraySize = lengthOrd(p.config, typ.indexType)
+    var i: TLoc = getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt))
     linefmt(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
             [i.r, arraySize])
-    specializeResetT(p, ropecg(p.module, "$1[$2]", [accessor, i.r]), typ[1])
+    specializeResetT(p, ropecg(p.module, "$1[$2]", [accessor, i.r]), typ.elementType)
     lineF(p, cpsStmts, "}$n", [])
   of tyObject:
-    for i in 0..<typ.len:
-      var x = typ[i]
-      if x != nil: x = x.skipTypes(skipPtrs)
-      specializeResetT(p, accessor.parentObj(p.module), x)
+    var x = typ.baseClass
+    if x != nil: x = x.skipTypes(skipPtrs)
+    specializeResetT(p, accessor.parentObj(p.module), x)
     if typ.n != nil: specializeResetN(p, accessor, typ.n, typ)
   of tyTuple:
     let typ = getUniqueType(typ)
-    for i in 0..<typ.len:
-      specializeResetT(p, ropecg(p.module, "$1.Field$2", [accessor, i]), typ[i])
+    for i, a in typ.ikids:
+      specializeResetT(p, ropecg(p.module, "$1.Field$2", [accessor, i]), a)
 
   of tyString, tyRef, tySequence:
     lineCg(p, cpsStmts, "#unsureAsgnRef((void**)&$1, NIM_NIL);$n", [accessor])
@@ -83,7 +81,7 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
       lineCg(p, cpsStmts, "$1.ClP_0 = NIM_NIL;$n", [accessor])
     else:
       lineCg(p, cpsStmts, "$1 = NIM_NIL;$n", [accessor])
-  of tyChar, tyBool, tyEnum, tyInt..tyUInt64:
+  of tyChar, tyBool, tyEnum, tyRange, tyInt..tyUInt64:
     lineCg(p, cpsStmts, "$1 = 0;$n", [accessor])
   of tyCstring, tyPointer, tyPtr, tyVar, tyLent:
     lineCg(p, cpsStmts, "$1 = NIM_NIL;$n", [accessor])
@@ -95,12 +93,12 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
     of ctInt8, ctInt16, ctInt32, ctInt64:
       lineCg(p, cpsStmts, "$1 = 0;$n", [accessor])
     else:
-      doAssert false, "unexpected set type kind"
-  of {tyNone, tyEmpty, tyNil, tyUntyped, tyTyped, tyGenericInvocation,
-      tyGenericParam, tyOrdinal, tyRange, tyOpenArray, tyForward, tyVarargs,
+      raiseAssert "unexpected set type kind"
+  of tyNone, tyEmpty, tyNil, tyUntyped, tyTyped, tyGenericInvocation,
+      tyGenericParam, tyOrdinal, tyOpenArray, tyForward, tyVarargs,
       tyUncheckedArray, tyProxy, tyBuiltInTypeClass, tyUserTypeClass,
       tyUserTypeClassInst, tyCompositeTypeClass, tyAnd, tyOr, tyNot,
-      tyAnything, tyStatic, tyFromExpr, tyConcept, tyVoid, tyIterable}:
+      tyAnything, tyStatic, tyFromExpr, tyConcept, tyVoid, tyIterable:
     discard
 
 proc specializeReset(p: BProc, a: TLoc) =

compiler/ccgstmts.nim

@@ -35,7 +35,9 @@ proc isAssignedImmediately(conf: ConfigRef; n: PNode): bool {.inline.} =
   if n.kind == nkEmpty:
     result = false
   elif n.kind in nkCallKinds and n[0] != nil and n[0].typ != nil and n[0].typ.skipTypes(abstractInst).kind == tyProc:
-    if isInvalidReturnType(conf, n[0].typ, true):
+    if n[0].kind == nkSym and sfConstructor in n[0].sym.flags:
+      result = true
+    elif isInvalidReturnType(conf, n[0].typ, true):
       # var v = f()
       # is transformed into: var v;  f(addr v)
       # where 'f' **does not** initialize the result!
@@ -48,6 +50,7 @@ proc isAssignedImmediately(conf: ConfigRef; n: PNode): bool {.inline.} =
     result = true
 
 proc inExceptBlockLen(p: BProc): int =
+  result = 0
   for x in p.nestedTryStmts:
     if x.inExcept: result.inc
 
@@ -69,7 +72,6 @@ template startBlock(p: BProc, start: FormatStr = "{$n",
 proc endBlock(p: BProc)
 
 proc genVarTuple(p: BProc, n: PNode) =
-  var tup, field: TLoc
   if n.kind != nkVarTuple: internalError(p.config, n.info, "genVarTuple")
 
   # if we have a something that's been captured, use the lowering instead:
@@ -81,7 +83,7 @@ proc genVarTuple(p: BProc, n: PNode) =
   # check only the first son
   var forHcr = treatGlobalDifferentlyForHCR(p.module, n[0].sym)
   let hcrCond = if forHcr: getTempName(p.module) else: ""
-  var hcrGlobals: seq[tuple[loc: TLoc, tp: Rope]]
+  var hcrGlobals: seq[tuple[loc: TLoc, tp: Rope]] = @[]
   # determine if the tuple is constructed at top-level scope or inside of a block (if/while/block)
   let isGlobalInBlock = forHcr and p.blocks.len > 2
   # do not close and reopen blocks if this is a 'global' but inside of a block (if/while/block)
@@ -93,7 +95,7 @@ proc genVarTuple(p: BProc, n: PNode) =
     startBlock(p)
 
   genLineDir(p, n)
-  initLocExpr(p, n[^1], tup)
+  var tup = initLocExpr(p, n[^1])
   var t = tup.t.skipTypes(abstractInst)
   for i in 0..<n.len-2:
     let vn = n[i]
@@ -106,7 +108,7 @@ proc genVarTuple(p: BProc, n: PNode) =
     else:
       assignLocalVar(p, vn)
       initLocalVar(p, v, immediateAsgn=isAssignedImmediately(p.config, n[^1]))
-    initLoc(field, locExpr, vn, tup.storage)
+    var field = initLoc(locExpr, vn, tup.storage)
     if t.kind == tyTuple:
       field.r = "$1.Field$2" % [rdLoc(tup), rope(i)]
     else:
@@ -167,7 +169,7 @@ proc endBlock(p: BProc, blockEnd: Rope) =
 proc endBlock(p: BProc) =
   let topBlock = p.blocks.len - 1
   let frameLen = p.blocks[topBlock].frameLen
-  var blockEnd: Rope
+  var blockEnd: Rope = ""
   if frameLen > 0:
     blockEnd.addf("FR_.len-=$1;$n", [frameLen.rope])
   if p.blocks[topBlock].label.len != 0:
@@ -242,8 +244,7 @@ proc genGotoState(p: BProc, n: PNode) =
   # switch (x.state) {
   #   case 0: goto STATE0;
   # ...
-  var a: TLoc
-  initLocExpr(p, n[0], a)
+  var a: TLoc = initLocExpr(p, n[0])
   lineF(p, cpsStmts, "switch ($1) {$n", [rdLoc(a)])
   p.flags.incl beforeRetNeeded
   lineF(p, cpsStmts, "case -1:$n", [])
@@ -262,13 +263,13 @@ proc genGotoState(p: BProc, n: PNode) =
 
 proc genBreakState(p: BProc, n: PNode, d: var TLoc) =
   var a: TLoc
-  initLoc(d, locExpr, n, OnUnknown)
+  d = initLoc(locExpr, n, OnUnknown)
 
   if n[0].kind == nkClosure:
-    initLocExpr(p, n[0][1], a)
+    a = initLocExpr(p, n[0][1])
     d.r = "(((NI*) $1)[1] < 0)" % [rdLoc(a)]
   else:
-    initLocExpr(p, n[0], a)
+    a = initLocExpr(p, n[0])
     # the environment is guaranteed to contain the 'state' field at offset 1:
     d.r = "((((NI*) $1.ClE_0)[1]) < 0)" % [rdLoc(a)]
 
@@ -288,11 +289,46 @@ proc potentialValueInit(p: BProc; v: PSym; value: PNode; result: var Rope) =
     #echo "New code produced for ", v.name.s, " ", p.config $ value.info
     genBracedInit(p, value, isConst = false, v.typ, result)
 
+proc genCppParamsForCtor(p: BProc; call: PNode; didGenTemp: var bool): string =
+  result = ""
+  var argsCounter = 0
+  let typ = skipTypes(call[0].typ, abstractInst)
+  assert(typ.kind == tyProc)
+  for i in 1..<call.len:
+    #if it's a type we can just generate here another initializer as we are in an initializer context
+    if call[i].kind == nkCall and call[i][0].kind == nkSym and call[i][0].sym.kind == skType:
+      if argsCounter > 0: result.add ","
+      result.add genCppInitializer(p.module, p, call[i][0].sym.typ, didGenTemp)
+    else:
+      #We need to test for temp in globals, see: #23657
+      let param = 
+        if typ[i].kind in {tyVar} and call[i].kind == nkHiddenAddr:
+          call[i][0]
+        else:
+          call[i]
+      if param.kind != nkBracketExpr or param.typ.kind in 
+        {tyRef, tyPtr, tyUncheckedArray, tyArray, tyOpenArray, 
+          tyVarargs, tySequence, tyString, tyCstring, tyTuple}:
+        let tempLoc = initLocExprSingleUse(p, param)
+        didGenTemp = didGenTemp or tempLoc.k == locTemp
+      genOtherArg(p, call, i, typ, result, argsCounter)
+
+proc genCppVarForCtor(p: BProc; call: PNode; decl: var Rope, didGenTemp: var bool) =
+  let params = genCppParamsForCtor(p, call, didGenTemp)
+  if params.len == 0:
+    decl = runtimeFormat("$#;\n", [decl])
+  else:
+    decl = runtimeFormat("$#($#);\n", [decl, params])
+
 proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
   if sfGoto in v.flags:
     # translate 'var state {.goto.} = X' into 'goto LX':
     genGotoVar(p, value)
     return
+  let imm = isAssignedImmediately(p.config, value)
+  let isCppCtorCall = p.module.compileToCpp and imm and
+    value.kind in nkCallKinds and value[0].kind == nkSym and
+    v.typ.kind != tyPtr and sfConstructor in value[0].sym.flags
   var targetProc = p
   var valueAsRope = ""
   potentialValueInit(p, v, value, valueAsRope)
@@ -304,7 +340,18 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
     if sfPure in v.flags:
       # v.owner.kind != skModule:
       targetProc = p.module.preInitProc
-    assignGlobalVar(targetProc, vn, valueAsRope)
+    if isCppCtorCall and not containsHiddenPointer(v.typ):
+      var didGenTemp = false
+      callGlobalVarCppCtor(targetProc, v, vn, value, didGenTemp)
+      if didGenTemp:
+        message(p.config, vn.info, warnGlobalVarConstructorTemporary, vn.sym.name.s)
+        #We fail to call the constructor in the global scope so we do the call inside the main proc
+        assignGlobalVar(targetProc, vn, valueAsRope)
+        var loc = initLocExprSingleUse(targetProc, value)
+        genAssignment(targetProc, v.loc, loc, {})
+    else:
+      assignGlobalVar(targetProc, vn, valueAsRope)
+
     # XXX: be careful here.
     # Global variables should not be zeromem-ed within loops
     # (see bug #20).
@@ -313,13 +360,12 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
     # global variables will be initialized to zero.
     if valueAsRope.len == 0:
       var loc = v.loc
-
       # When the native TLS is unavailable, a global thread-local variable needs
       # one more layer of indirection in order to access the TLS block.
       # Only do this for complex types that may need a call to `objectInit`
       if sfThread in v.flags and emulatedThreadVars(p.config) and
         isComplexValueType(v.typ):
-        initLocExprSingleUse(p.module.preInitProc, vn, loc)
+        loc = initLocExprSingleUse(p.module.preInitProc, vn)
       genObjectInit(p.module.preInitProc, cpsInit, v.typ, loc, constructObj)
     # Alternative construction using default constructor (which may zeromem):
     # if sfImportc notin v.flags: constructLoc(p.module.preInitProc, v.loc)
@@ -327,31 +373,25 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
       genVarPrototype(p.module.g.generatedHeader, vn)
     registerTraverseProc(p, v)
   else:
-    let imm = isAssignedImmediately(p.config, value)
     if imm and p.module.compileToCpp and p.splitDecls == 0 and
-        not containsHiddenPointer(v.typ):
+        not containsHiddenPointer(v.typ) and
+        nimErrorFlagAccessed notin p.flags:
       # C++ really doesn't like things like 'Foo f; f = x' as that invokes a
       # parameterless constructor followed by an assignment operator. So we
       # generate better code here: 'Foo f = x;'
       genLineDir(p, vn)
-      let decl = localVarDecl(p, vn)
+      var decl = localVarDecl(p, vn)
       var tmp: TLoc
-      if value.kind in nkCallKinds and value[0].kind == nkSym and
-           sfConstructor in value[0].sym.flags:
-        var params = newRopeAppender()
-        var argsCounter = 0
-        let typ = skipTypes(value[0].typ, abstractInst)
-        assert(typ.kind == tyProc)
-        for i in 1..<value.len:
-          assert(typ.len == typ.n.len)
-          genOtherArg(p, value, i, typ, params, argsCounter)
-        if params.len == 0:
-          lineF(p, cpsStmts, "$#;$n", [decl])
-        else:
-          lineF(p, cpsStmts, "$#($#);$n", [decl, params])
+      if isCppCtorCall:
+        var didGenTemp = false
+        genCppVarForCtor(p, value, decl, didGenTemp)
+        line(p, cpsStmts, decl)
       else:
-        initLocExprSingleUse(p, value, tmp)
-        lineF(p, cpsStmts, "$# = $#;$n", [decl, tmp.rdLoc])
+        tmp = initLocExprSingleUse(p, value)
+        if value.kind == nkEmpty:
+          lineF(p, cpsStmts, "$#;\n", [decl])
+        else:
+          lineF(p, cpsStmts, "$# = $#;\n", [decl, tmp.rdLoc])
       return
     assignLocalVar(p, vn)
     initLocalVar(p, v, imm)
@@ -378,7 +418,8 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
     startBlock(targetProc)
   if value.kind != nkEmpty and valueAsRope.len == 0:
     genLineDir(targetProc, vn)
-    loadInto(targetProc, vn, value, v.loc)
+    if not isCppCtorCall:
+      loadInto(targetProc, vn, value, v.loc)
   if forHcr:
     endBlock(targetProc)
 
@@ -395,8 +436,7 @@ proc genSingleVar(p: BProc, a: PNode) =
 
 proc genClosureVar(p: BProc, a: PNode) =
   var immediateAsgn = a[2].kind != nkEmpty
-  var v: TLoc
-  initLocExpr(p, a[0], v)
+  var v: TLoc = initLocExpr(p, a[0])
   genLineDir(p, a)
   if immediateAsgn:
     loadInto(p, a[0], a[2], v)
@@ -431,7 +471,7 @@ proc genIf(p: BProc, n: PNode, d: var TLoc) =
     a: TLoc
     lelse: TLabel
   if not isEmptyType(n.typ) and d.k == locNone:
-    getTemp(p, n.typ, d)
+    d = getTemp(p, n.typ)
   genLineDir(p, n)
   let lend = getLabel(p)
   for it in n.sons:
@@ -439,7 +479,7 @@ proc genIf(p: BProc, n: PNode, d: var TLoc) =
     if d.k == locTemp and isEmptyType(n.typ): d.k = locNone
     if it.len == 2:
       startBlock(p)
-      initLocExprSingleUse(p, it[0], a)
+      a = initLocExprSingleUse(p, it[0])
       lelse = getLabel(p)
       inc(p.labels)
       lineF(p, cpsStmts, "if (!$1) goto $2;$n",
@@ -507,7 +547,7 @@ proc genComputedGoto(p: BProc; n: PNode) =
   # wrapped inside stmt lists by inject destructors won't be recognised
   let n = n.flattenStmts()
   var casePos = -1
-  var arraySize: int
+  var arraySize: int = 0
   for i in 0..<n.len:
     let it = n[i]
     if it.kind == nkCaseStmt:
@@ -541,8 +581,7 @@ proc genComputedGoto(p: BProc; n: PNode) =
     genStmts(p, n[j])
 
   let caseStmt = n[casePos]
-  var a: TLoc
-  initLocExpr(p, caseStmt[0], a)
+  var a: TLoc = initLocExpr(p, caseStmt[0])
   # first goto:
   lineF(p, cpsStmts, "goto *$#[$#];$n", [tmp, a.rdLoc])
 
@@ -580,8 +619,7 @@ proc genComputedGoto(p: BProc; n: PNode) =
       else:
         genStmts(p, it)
 
-    var a: TLoc
-    initLocExpr(p, caseStmt[0], a)
+    var a: TLoc = initLocExpr(p, caseStmt[0])
     lineF(p, cpsStmts, "goto *$#[$#];$n", [tmp, a.rdLoc])
     endBlock(p)
 
@@ -609,11 +647,11 @@ proc genWhileStmt(p: BProc, t: PNode) =
     else:
       p.breakIdx = startBlock(p, "while (1) {$n")
       p.blocks[p.breakIdx].isLoop = true
-      initLocExpr(p, t[0], a)
+      a = initLocExpr(p, t[0])
       if (t[0].kind != nkIntLit) or (t[0].intVal == 0):
         lineF(p, cpsStmts, "if (!$1) goto ", [rdLoc(a)])
         assignLabel(p.blocks[p.breakIdx], p.s(cpsStmts))
-        lineF(p, cpsStmts, ";$n", [])
+        appcg(p, cpsStmts, ";$n", [])
       genStmts(p, loopBody)
 
       if optProfiler in p.options:
@@ -628,7 +666,7 @@ proc genBlock(p: BProc, n: PNode, d: var TLoc) =
     # bug #4505: allocate the temp in the outer scope
     # so that it can escape the generated {}:
     if d.k == locNone:
-      getTemp(p, n.typ, d)
+      d = getTemp(p, n.typ)
     d.flags.incl(lfEnforceDeref)
   preserveBreakIdx:
     p.breakIdx = startBlock(p)
@@ -648,14 +686,13 @@ proc genParForStmt(p: BProc, t: PNode) =
 
   preserveBreakIdx:
     let forLoopVar = t[0].sym
-    var rangeA, rangeB: TLoc
     assignLocalVar(p, t[0])
     #initLoc(forLoopVar.loc, locLocalVar, forLoopVar.typ, onStack)
     #discard mangleName(forLoopVar)
     let call = t[1]
-    assert(call.len in {4, 5})
-    initLocExpr(p, call[1], rangeA)
-    initLocExpr(p, call[2], rangeB)
+    assert(call.len == 4 or call.len == 5)
+    var rangeA = initLocExpr(p, call[1])
+    var rangeB = initLocExpr(p, call[2])
 
     # $n at the beginning because of #9710
     if call.len == 4: # procName(a, b, annotation)
@@ -672,8 +709,7 @@ proc genParForStmt(p: BProc, t: PNode) =
                     rangeA.rdLoc, rangeB.rdLoc,
                     call[3].getStr.rope])
     else: # `||`(a, b, step, annotation)
-      var step: TLoc
-      initLocExpr(p, call[3], step)
+      var step: TLoc = initLocExpr(p, call[3])
       lineF(p, cpsStmts, "$n#pragma omp $5$n" &
                     "for ($1 = $2; $1 <= $3; $1 += $4)",
                     [forLoopVar.loc.rdLoc,
@@ -719,6 +755,18 @@ proc raiseExit(p: BProc) =
       lineCg(p, cpsStmts, "if (NIM_UNLIKELY(*nimErr_)) goto LA$1_;$n",
         [p.nestedTryStmts[^1].label])
 
+proc raiseExitCleanup(p: BProc, destroy: string) =
+  assert p.config.exc == excGoto
+  if nimErrorFlagDisabled notin p.flags:
+    p.flags.incl nimErrorFlagAccessed
+    if p.nestedTryStmts.len == 0:
+      p.flags.incl beforeRetNeeded
+      # easy case, simply goto 'ret':
+      lineCg(p, cpsStmts, "if (NIM_UNLIKELY(*nimErr_)) {$1; goto BeforeRet_;}$n", [destroy])
+    else:
+      lineCg(p, cpsStmts, "if (NIM_UNLIKELY(*nimErr_)) {$2; goto LA$1_;}$n",
+        [p.nestedTryStmts[^1].label, destroy])
+
 proc finallyActions(p: BProc) =
   if p.config.exc != excGoto and p.nestedTryStmts.len > 0 and p.nestedTryStmts[^1].inExcept:
     # if the current try stmt have a finally block,
@@ -743,8 +791,7 @@ proc raiseInstr(p: BProc; result: var Rope) =
 
 proc genRaiseStmt(p: BProc, t: PNode) =
   if t[0].kind != nkEmpty:
-    var a: TLoc
-    initLocExprSingleUse(p, t[0], a)
+    var a: TLoc = initLocExprSingleUse(p, t[0])
     finallyActions(p)
     var e = rdLoc(a)
     discard getTypeDesc(p.module, t[0].typ)
@@ -766,11 +813,7 @@ proc genRaiseStmt(p: BProc, t: PNode) =
   else:
     finallyActions(p)
     genLineDir(p, t)
-    # reraise the last exception:
-    if p.config.exc == excCpp:
-      line(p, cpsStmts, "throw;\n")
-    else:
-      linefmt(p, cpsStmts, "#reraiseException();$n", [])
+    linefmt(p, cpsStmts, "#reraiseException();$n", [])
   raiseInstr(p, p.s(cpsStmts))
 
 template genCaseGenericBranch(p: BProc, b: PNode, e: TLoc,
@@ -778,12 +821,12 @@ template genCaseGenericBranch(p: BProc, b: PNode, e: TLoc,
   var x, y: TLoc
   for i in 0..<b.len - 1:
     if b[i].kind == nkRange:
-      initLocExpr(p, b[i][0], x)
-      initLocExpr(p, b[i][1], y)
+      x = initLocExpr(p, b[i][0])
+      y = initLocExpr(p, b[i][1])
       lineCg(p, cpsStmts, rangeFormat,
            [rdCharLoc(e), rdCharLoc(x), rdCharLoc(y), labl])
     else:
-      initLocExpr(p, b[i], x)
+      x = initLocExpr(p, b[i])
       lineCg(p, cpsStmts, eqFormat, [rdCharLoc(e), rdCharLoc(x), labl])
 
 proc genCaseSecondPass(p: BProc, t: PNode, d: var TLoc,
@@ -825,8 +868,7 @@ template genIfForCaseUntil(p: BProc, t: PNode, d: var TLoc,
 
 template genCaseGeneric(p: BProc, t: PNode, d: var TLoc,
                     rangeFormat, eqFormat: FormatStr) =
-  var a: TLoc
-  initLocExpr(p, t[0], a)
+  var a: TLoc = initLocExpr(p, t[0])
   var lend = genIfForCaseUntil(p, t, d, rangeFormat, eqFormat, t.len-1, a)
   fixLabel(p, lend)
 
@@ -836,8 +878,8 @@ proc genCaseStringBranch(p: BProc, b: PNode, e: TLoc, labl: TLabel,
   var x: TLoc
   for i in 0..<b.len - 1:
     assert(b[i].kind != nkRange)
-    initLocExpr(p, b[i], x)
-    var j: int
+    x = initLocExpr(p, b[i])
+    var j: int = 0
     case b[i].kind
     of nkStrLit..nkTripleStrLit:
       j = int(hashString(p.config, b[i].strVal) and high(branches))
@@ -860,8 +902,7 @@ proc genStringCase(p: BProc, t: PNode, stringKind: TTypeKind, d: var TLoc) =
     var bitMask = math.nextPowerOfTwo(strings) - 1
     var branches: seq[Rope]
     newSeq(branches, bitMask + 1)
-    var a: TLoc
-    initLocExpr(p, t[0], a) # fist pass: generate ifs+goto:
+    var a: TLoc = initLocExpr(p, t[0]) # first pass: generate ifs+goto:
     var labId = p.labels
     for i in 1..<t.len:
       inc(p.labels)
@@ -897,6 +938,7 @@ proc genStringCase(p: BProc, t: PNode, stringKind: TTypeKind, d: var TLoc) =
       genCaseGeneric(p, t, d, "", "if (#eqStrings($1, $2)) goto $3;$n")
 
 proc branchHasTooBigRange(b: PNode): bool =
+  result = false
   for it in b:
     # last son is block
     if (it.kind == nkRange) and
@@ -904,6 +946,7 @@ proc branchHasTooBigRange(b: PNode): bool =
       return true
 
 proc ifSwitchSplitPoint(p: BProc, n: PNode): int =
+  result = 0
   for i in 1..<n.len:
     var branch = n[i]
     var stmtBlock = lastSon(branch)
@@ -939,8 +982,7 @@ proc genOrdinalCase(p: BProc, n: PNode, d: var TLoc) =
   var splitPoint = ifSwitchSplitPoint(p, n)
 
   # generate if part (might be empty):
-  var a: TLoc
-  initLocExpr(p, n[0], a)
+  var a: TLoc = initLocExpr(p, n[0])
   var lend = if splitPoint > 0: genIfForCaseUntil(p, n, d,
                     rangeFormat = "if ($1 >= $2 && $1 <= $3) goto $4;$n",
                     eqFormat = "if ($1 == $2) goto $3;$n",
@@ -962,15 +1004,18 @@ proc genOrdinalCase(p: BProc, n: PNode, d: var TLoc) =
         hasDefault = true
       exprBlock(p, branch.lastSon, d)
       lineF(p, cpsStmts, "break;$n", [])
-    if (hasAssume in CC[p.config.cCompiler].props) and not hasDefault:
-      lineF(p, cpsStmts, "default: __assume(0);$n", [])
+    if not hasDefault:
+      if hasBuiltinUnreachable in CC[p.config.cCompiler].props:
+        lineF(p, cpsStmts, "default: __builtin_unreachable();$n", [])
+      elif hasAssume in CC[p.config.cCompiler].props:
+        lineF(p, cpsStmts, "default: __assume(0);$n", [])
     lineF(p, cpsStmts, "}$n", [])
   if lend != "": fixLabel(p, lend)
 
 proc genCase(p: BProc, t: PNode, d: var TLoc) =
   genLineDir(p, t)
   if not isEmptyType(t.typ) and d.k == locNone:
-    getTemp(p, t.typ, d)
+    d = getTemp(p, t.typ)
   case skipTypes(t[0].typ, abstractVarRange).kind
   of tyString:
     genStringCase(p, t, tyString, d)
@@ -996,7 +1041,7 @@ proc genRestoreFrameAfterException(p: BProc) =
 proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =
   #[ code to generate:
 
-    std::exception_ptr error = nullptr;
+    std::exception_ptr error;
     try {
       body;
     } catch (Exception e) {
@@ -1021,13 +1066,13 @@ proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =
   p.module.includeHeader("<exception>")
 
   if not isEmptyType(t.typ) and d.k == locNone:
-    getTemp(p, t.typ, d)
+    d = getTemp(p, t.typ)
   genLineDir(p, t)
 
   inc(p.labels, 2)
   let etmp = p.labels
-
-  p.procSec(cpsInit).add(ropecg(p.module, "\tstd::exception_ptr T$1_ = nullptr;", [etmp]))
+  #init on locals, fixes #23306
+  lineCg(p, cpsLocals, "std::exception_ptr T$1_;$n", [etmp])
 
   let fin = if t[^1].kind == nkFinally: t[^1] else: nil
   p.nestedTryStmts.add((fin, false, 0.Natural))
@@ -1061,7 +1106,6 @@ proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =
       if hasIf: lineF(p, cpsStmts, "else ", [])
       startBlock(p)
       # we handled the error:
-      linefmt(p, cpsStmts, "T$1_ = nullptr;$n", [etmp])
       expr(p, t[i][0], d)
       linefmt(p, cpsStmts, "#popCurrentException();$n", [])
       endBlock(p)
@@ -1124,7 +1168,7 @@ proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =
 
       if t[i].len == 1:
         # general except section:
-        startBlock(p, "catch (...) {", [])
+        startBlock(p, "catch (...) {$n", [])
         genExceptBranchBody(t[i][0])
         endBlock(p)
         catchAllPresent = true
@@ -1150,7 +1194,7 @@ proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =
   # general finally block:
   if t.len > 0 and t[^1].kind == nkFinally:
     if not catchAllPresent:
-      startBlock(p, "catch (...) {", [])
+      startBlock(p, "catch (...) {$n", [])
       genRestoreFrameAfterException(p)
       linefmt(p, cpsStmts, "T$1_ = std::current_exception();$n", [etmp])
       endBlock(p)
@@ -1187,7 +1231,7 @@ proc genTryCppOld(p: BProc, t: PNode, d: var TLoc) =
     expr(p, body, d)
 
   if not isEmptyType(t.typ) and d.k == locNone:
-    getTemp(p, t.typ, d)
+    d = getTemp(p, t.typ)
   genLineDir(p, t)
   cgsym(p.module, "popCurrentExceptionEx")
   let fin = if t[^1].kind == nkFinally: t[^1] else: nil
@@ -1265,7 +1309,7 @@ proc genTryGoto(p: BProc; t: PNode; d: var TLoc) =
   p.flags.incl nimErrorFlagAccessed
 
   if not isEmptyType(t.typ) and d.k == locNone:
-    getTemp(p, t.typ, d)
+    d = getTemp(p, t.typ)
 
   expr(p, t[0], d)
 
@@ -1300,7 +1344,8 @@ proc genTryGoto(p: BProc; t: PNode; d: var TLoc) =
         let memberName = if p.module.compileToCpp: "m_type" else: "Sup.m_type"
         if optTinyRtti in p.config.globalOptions:
           let checkFor = $getObjDepth(t[i][j].typ)
-          appcg(p.module, orExpr, "#isObjDisplayCheck(#nimBorrowCurrentException()->$1, $2, $3)", [memberName, checkFor,  $genDisplayElem(MD5Digest(hashType(t[i][j].typ, p.config)))])
+          appcg(p.module, orExpr, "#isObjDisplayCheck(#nimBorrowCurrentException()->$1, $2, $3)",
+            [memberName, checkFor, $genDisplayElem(MD5Digest(hashType(t[i][j].typ, p.config)))])
         else:
           let checkFor = genTypeInfoV1(p.module, t[i][j].typ, t[i][j].info)
           appcg(p.module, orExpr, "#isObj(#nimBorrowCurrentException()->$1, $2)", [memberName, checkFor])
@@ -1371,7 +1416,7 @@ proc genTrySetjmp(p: BProc, t: PNode, d: var TLoc) =
   #    propagateCurrentException();
   #
   if not isEmptyType(t.typ) and d.k == locNone:
-    getTemp(p, t.typ, d)
+    d = getTemp(p, t.typ)
   let quirkyExceptions = p.config.exc == excQuirky or
       (t.kind == nkHiddenTryStmt and sfSystemModule in p.module.module.flags)
   if not quirkyExceptions:
@@ -1380,7 +1425,7 @@ proc genTrySetjmp(p: BProc, t: PNode, d: var TLoc) =
     p.flags.incl noSafePoints
   genLineDir(p, t)
   cgsym(p.module, "Exception")
-  var safePoint: Rope
+  var safePoint: Rope = ""
   if not quirkyExceptions:
     safePoint = getTempName(p.module)
     linefmt(p, cpsLocals, "#TSafePoint $1;$n", [safePoint])
@@ -1445,7 +1490,8 @@ proc genTrySetjmp(p: BProc, t: PNode, d: var TLoc) =
         let memberName = if p.module.compileToCpp: "m_type" else: "Sup.m_type"
         if optTinyRtti in p.config.globalOptions:
           let checkFor = $getObjDepth(t[i][j].typ)
-          appcg(p.module, orExpr, "#isObjDisplayCheck(#nimBorrowCurrentException()->$1, $2, $3)", [memberName, checkFor,  $genDisplayElem(MD5Digest(hashType(t[i][j].typ, p.config)))])
+          appcg(p.module, orExpr, "#isObjDisplayCheck(#nimBorrowCurrentException()->$1, $2, $3)",
+              [memberName, checkFor, $genDisplayElem(MD5Digest(hashType(t[i][j].typ, p.config)))])
         else:
           let checkFor = genTypeInfoV1(p.module, t[i][j].typ, t[i][j].info)
           appcg(p.module, orExpr, "#isObj(#nimBorrowCurrentException()->$1, $2)", [memberName, checkFor])
@@ -1476,15 +1522,19 @@ proc genTrySetjmp(p: BProc, t: PNode, d: var TLoc) =
 
 proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
   var res = ""
-  for it in t.sons:
+  let offset =
+    if isAsmStmt: 1 # first son is pragmas
+    else: 0
+
+  for i in offset..<t.len:
+    let it = t[i]
     case it.kind
     of nkStrLit..nkTripleStrLit:
       res.add(it.strVal)
     of nkSym:
       var sym = it.sym
       if sym.kind in {skProc, skFunc, skIterator, skMethod}:
-        var a: TLoc
-        initLocExpr(p, it, a)
+        var a: TLoc = initLocExpr(p, it)
         res.add($rdLoc(a))
       elif sym.kind == skType:
         res.add($getTypeDesc(p.module, sym.typ))
@@ -1496,8 +1546,7 @@ proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
       res.add($getTypeDesc(p.module, it.typ))
     else:
       discard getTypeDesc(p.module, skipTypes(it.typ, abstractPtrs))
-      var a: TLoc
-      initLocExpr(p, it, a)
+      var a: TLoc = initLocExpr(p, it)
       res.add($a.rdLoc)
 
   if isAsmStmt and hasGnuAsm in CC[p.config.cCompiler].props:
@@ -1522,6 +1571,21 @@ proc genAsmStmt(p: BProc, t: PNode) =
   assert(t.kind == nkAsmStmt)
   genLineDir(p, t)
   var s = newRopeAppender()
+
+  var asmSyntax = ""
+  if (let p = t[0]; p.kind == nkPragma):
+    for i in p:
+      if whichPragma(i) == wAsmSyntax:
+        asmSyntax = i[1].strVal
+
+  if asmSyntax != "" and 
+     not (
+      asmSyntax == "gcc" and hasGnuAsm in CC[p.config.cCompiler].props or
+      asmSyntax == "vcc" and hasGnuAsm notin CC[p.config.cCompiler].props):
+    localError(
+      p.config, t.info, 
+      "Your compiler does not support the specified inline assembler")
+  
   genAsmOrEmitStmt(p, t, isAsmStmt=true, s)
   # see bug #2362, "top level asm statements" seem to be a mis-feature
   # but even if we don't do this, the example in #2362 cannot possibly
@@ -1599,11 +1663,10 @@ when false:
     expr(p, call, d)
 
 proc asgnFieldDiscriminant(p: BProc, e: PNode) =
-  var a, tmp: TLoc
   var dotExpr = e[0]
   if dotExpr.kind == nkCheckedFieldExpr: dotExpr = dotExpr[0]
-  initLocExpr(p, e[0], a)
-  getTemp(p, a.t, tmp)
+  var a = initLocExpr(p, e[0])
+  var tmp: TLoc = getTemp(p, a.t)
   expr(p, e[1], tmp)
   if p.inUncheckedAssignSection == 0:
     let field = dotExpr[1].sym
@@ -1621,9 +1684,8 @@ proc genAsgn(p: BProc, e: PNode, fastAsgn: bool) =
   else:
     let le = e[0]
     let ri = e[1]
-    var a: TLoc
-    discard getTypeDesc(p.module, le.typ.skipTypes(skipPtrs), skVar)
-    initLoc(a, locNone, le, OnUnknown)
+    var a: TLoc = initLoc(locNone, le, OnUnknown)
+    discard getTypeDesc(p.module, le.typ.skipTypes(skipPtrs), dkVar)
     a.flags.incl(lfEnforceDeref)
     a.flags.incl(lfPrepareForMutation)
     genLineDir(p, le) # it can be a nkBracketExpr, which may raise
@@ -1635,7 +1697,7 @@ proc genAsgn(p: BProc, e: PNode, fastAsgn: bool) =
     loadInto(p, le, ri, a)
 
 proc genStmts(p: BProc, t: PNode) =
-  var a: TLoc
+  var a: TLoc = default(TLoc)
 
   let isPush = p.config.hasHint(hintExtendedContext)
   if isPush: pushInfoContext(p.config, t.info)

compiler/ccgtrav.nim

@@ -21,7 +21,7 @@ const
 
 proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType)
 proc genCaseRange(p: BProc, branch: PNode)
-proc getTemp(p: BProc, t: PType, result: var TLoc; needsInit=false)
+proc getTemp(p: BProc, t: PType, needsInit=false): TLoc
 
 proc genTraverseProc(c: TTraversalClosure, accessor: Rope, n: PNode;
                      typ: PType) =
@@ -71,38 +71,36 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType) =
   case typ.kind
   of tyGenericInst, tyGenericBody, tyTypeDesc, tyAlias, tyDistinct, tyInferred,
      tySink, tyOwned:
-    genTraverseProc(c, accessor, lastSon(typ))
+    genTraverseProc(c, accessor, skipModifier(typ))
   of tyArray:
-    let arraySize = lengthOrd(c.p.config, typ[0])
-    var i: TLoc
-    getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt), i)
+    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)
     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[1])
+    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:
-    for i in 0..<typ.len:
-      var x = typ[i]
-      if x != nil: x = x.skipTypes(skipPtrs)
-      genTraverseProc(c, accessor.parentObj(c.p.module), x)
+    var x = typ.baseClass
+    if x != nil: x = x.skipTypes(skipPtrs)
+    genTraverseProc(c, accessor.parentObj(c.p.module), x)
     if typ.n != nil: genTraverseProc(c, accessor, typ.n, typ)
   of tyTuple:
     let typ = getUniqueType(typ)
-    for i in 0..<typ.len:
-      genTraverseProc(c, ropecg(c.p.module, "$1.Field$2", [accessor, i]), typ[i])
+    for i, a in typ.ikids:
+      genTraverseProc(c, ropecg(c.p.module, "$1.Field$2", [accessor, i]), a)
   of tyRef:
     lineCg(p, cpsStmts, visitorFrmt, [accessor, c.visitorFrmt])
   of tySequence:
     if optSeqDestructors notin c.p.module.config.globalOptions:
       lineCg(p, cpsStmts, visitorFrmt, [accessor, c.visitorFrmt])
-    elif containsGarbageCollectedRef(typ.lastSon):
+    elif containsGarbageCollectedRef(typ.elementType):
       # destructor based seqs are themselves not traced but their data is, if
       # they contain a GC'ed type:
       lineCg(p, cpsStmts, "#nimGCvisitSeq((void*)$1, $2);$n", [accessor, c.visitorFrmt])
@@ -119,17 +117,15 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType) =
 proc genTraverseProcSeq(c: TTraversalClosure, accessor: Rope, typ: PType) =
   var p = c.p
   assert typ.kind == tySequence
-  var i: TLoc
-  getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt), i)
+  var i = getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt))
   var oldCode = p.s(cpsStmts)
   freeze oldCode
-  var a: TLoc
-  a.r = accessor
+  var a = TLoc(r: accessor)
 
   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[0])
+  genTraverseProc(c, "$1$3[$2]" % [accessor, i.r, dataField(c.p)], typ.elementType)
   if p.s(cpsStmts).len == oldLen:
     # do not emit dummy long loops for faster debug builds:
     p.s(cpsStmts) = oldCode
@@ -137,7 +133,6 @@ proc genTraverseProcSeq(c: TTraversalClosure, accessor: Rope, typ: PType) =
     lineF(p, cpsStmts, "}$n", [])
 
 proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
-  var c: TTraversalClosure
   var p = newProc(nil, m)
   result = "Marker_" & getTypeName(m, origTyp, sig)
   let
@@ -150,18 +145,19 @@ proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
   lineF(p, cpsLocals, "$1 a;$n", [t])
   lineF(p, cpsInit, "a = ($1)p;$n", [t])
 
-  c.p = p
-  c.visitorFrmt = "op" # "#nimGCvisit((void*)$1, op);$n"
+  var c = TTraversalClosure(p: p,
+    visitorFrmt: "op" # "#nimGCvisit((void*)$1, op);$n"
+    )
 
   assert typ.kind != tyTypeDesc
   if typ.kind == tySequence:
     genTraverseProcSeq(c, "a".rope, typ)
   else:
-    if skipTypes(typ[0], typedescInst+{tyOwned}).kind == tyArray:
+    if skipTypes(typ.elementType, typedescInst+{tyOwned}).kind == tyArray:
       # C's arrays are broken beyond repair:
-      genTraverseProc(c, "a".rope, typ[0])
+      genTraverseProc(c, "a".rope, typ.elementType)
     else:
-      genTraverseProc(c, "(*a)".rope, typ[0])
+      genTraverseProc(c, "(*a)".rope, typ.elementType)
 
   let generatedProc = "$1 {$n$2$3$4}\n" %
         [header, p.s(cpsLocals), p.s(cpsInit), p.s(cpsStmts)]
@@ -177,7 +173,6 @@ proc genTraverseProc(m: BModule, origTyp: PType; sig: SigHash): Rope =
 proc genTraverseProcForGlobal(m: BModule, s: PSym; info: TLineInfo): Rope =
   discard genTypeInfoV1(m, s.loc.t, info)
 
-  var c: TTraversalClosure
   var p = newProc(nil, m)
   var sLoc = rdLoc(s.loc)
   result = getTempName(m)
@@ -186,8 +181,10 @@ proc genTraverseProcForGlobal(m: BModule, s: PSym; info: TLineInfo): Rope =
     accessThreadLocalVar(p, s)
     sLoc = "NimTV_->" & sLoc
 
-  c.visitorFrmt = "0" # "#nimGCvisit((void*)$1, 0);$n"
-  c.p = p
+  var c = TTraversalClosure(p: p,
+    visitorFrmt: "0" # "#nimGCvisit((void*)$1, 0);$n"
+  )
+
   let header = "static N_NIMCALL(void, $1)(void)" % [result]
   genTraverseProc(c, sLoc, s.loc.t)
 

compiler/ccgutils.nim

@@ -10,8 +10,10 @@
 # This module declares some helpers for the C code generator.
 
 import
-  ast, types, hashes, strutils, msgs, wordrecg,
-  platform, trees, options, cgendata
+  ast, types, msgs, wordrecg,
+  platform, trees, options, cgendata, mangleutils
+
+import std/[hashes, strutils, formatfloat]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -19,13 +21,16 @@ when defined(nimPreviewSlimSystem):
 proc getPragmaStmt*(n: PNode, w: TSpecialWord): PNode =
   case n.kind
   of nkStmtList:
+    result = nil
     for i in 0..<n.len:
       result = getPragmaStmt(n[i], w)
       if result != nil: break
   of nkPragma:
+    result = nil
     for i in 0..<n.len:
       if whichPragma(n[i]) == w: return n[i]
-  else: discard
+  else:
+    result = nil
 
 proc stmtsContainPragma*(n: PNode, w: TSpecialWord): bool =
   result = getPragmaStmt(n, w) != nil
@@ -63,53 +68,6 @@ proc makeSingleLineCString*(s: string): string =
     c.toCChar(result)
   result.add('\"')
 
-proc mangle*(name: string): string =
-  result = newStringOfCap(name.len)
-  var start = 0
-  if name[0] in Digits:
-    result.add("X" & name[0])
-    start = 1
-  var requiresUnderscore = false
-  template special(x) =
-    result.add x
-    requiresUnderscore = true
-  for i in start..<name.len:
-    let c = name[i]
-    case c
-    of 'a'..'z', '0'..'9', 'A'..'Z':
-      result.add(c)
-    of '_':
-      # we generate names like 'foo_9' for scope disambiguations and so
-      # disallow this here:
-      if i > 0 and i < name.len-1 and name[i+1] in Digits:
-        discard
-      else:
-        result.add(c)
-    of '$': special "dollar"
-    of '%': special "percent"
-    of '&': special "amp"
-    of '^': special "roof"
-    of '!': special "emark"
-    of '?': special "qmark"
-    of '*': special "star"
-    of '+': special "plus"
-    of '-': special "minus"
-    of '/': special "slash"
-    of '\\': special "backslash"
-    of '=': special "eq"
-    of '<': special "lt"
-    of '>': special "gt"
-    of '~': special "tilde"
-    of ':': special "colon"
-    of '.': special "dot"
-    of '@': special "at"
-    of '|': special "bar"
-    else:
-      result.add("X" & toHex(ord(c), 2))
-      requiresUnderscore = true
-  if requiresUnderscore:
-    result.add "_"
-
 proc mapSetType(conf: ConfigRef; typ: PType): TCTypeKind =
   case int(getSize(conf, typ))
   of 1: result = ctInt8
@@ -122,13 +80,19 @@ proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
   var pt = skipTypes(s.typ, typedescInst)
   assert skResult != s.kind
 
-  if tfByRef in pt.flags: return true
+  #note precedence: params override types
+  if optByRef in s.options: return true
+  elif sfByCopy in s.flags: return false
+  elif tfByRef in pt.flags: return true
   elif tfByCopy in pt.flags: return false
   case pt.kind
   of tyObject:
     if s.typ.sym != nil and sfForward in s.typ.sym.flags:
       # forwarded objects are *always* passed by pointers for consistency!
       result = true
+    elif s.typ.kind == tySink and conf.selectedGC notin {gcArc, gcAtomicArc, gcOrc, gcHooks}:
+      # bug #23354:
+      result = false
     elif (optByRef in s.options) or (getSize(conf, pt) > conf.target.floatSize * 3):
       result = true           # requested anyway
     elif (tfFinal in pt.flags) and (pt[0] == nil):
@@ -145,3 +109,62 @@ proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
     result = not (pt.kind in {tyVar, tyArray, tyOpenArray, tyVarargs, tyRef, tyPtr, tyPointer} or
       pt.kind == tySet and mapSetType(conf, pt) == ctArray)
 
+proc encodeName*(name: string): string =
+  result = mangle(name)
+  result = $result.len & result
+
+proc makeUnique(m: BModule; s: PSym, name: string = ""): string =
+  result = if name == "": s.name.s else: name
+  result.add "__"
+  result.add m.g.graph.ifaces[s.itemId.module].uniqueName
+  result.add "_u"
+  result.add $s.itemId.item
+
+proc encodeSym*(m: BModule; s: PSym; makeUnique: bool = false): string =
+  #Module::Type
+  var name = s.name.s
+  if makeUnique:
+    name = makeUnique(m, s, name)
+  "N" & encodeName(s.skipGenericOwner.name.s) & encodeName(name) & "E"
+
+proc encodeType*(m: BModule; t: PType): string =
+  result = ""
+  var kindName = ($t.kind)[2..^1]
+  kindName[0] = toLower($kindName[0])[0]
+  case t.kind
+  of tyObject, tyEnum, tyDistinct, tyUserTypeClass, tyGenericParam:
+    result = encodeSym(m, t.sym)
+  of tyGenericInst, tyUserTypeClassInst, tyGenericBody:
+    result = encodeName(t[0].sym.name.s)
+    result.add "I"
+    for i in 1..<t.len - 1:
+      result.add encodeType(m, t[i])
+    result.add "E"
+  of tySequence, tyOpenArray, tyArray, tyVarargs, tyTuple, tyProc, tySet, tyTypeDesc,
+    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 i in 0..<t.len:
+      let s = t[i]
+      if s.isNil: continue
+      result.add encodeType(m, s)
+    result.add "E"
+  of tyRange:
+    var val = "range_"
+    if t.n[0].typ.kind in {tyFloat..tyFloat128}:
+      val.addFloat t.n[0].floatVal
+      val.add "_"
+      val.addFloat t.n[1].floatVal
+    else:
+      val.add $t.n[0].intVal & "_" & $t.n[1].intVal
+    result = encodeName(val)
+  of tyString..tyUInt64, tyPointer, tyBool, tyChar, tyVoid, tyAnything, tyNil, tyEmpty:
+    result = encodeName(kindName)
+  of tyAlias, tyInferred, tyOwned:
+    result = encodeType(m, t.elementType)
+  else:
+    assert false, "encodeType " & $t.kind
+

compiler/cgendata.nim

@@ -10,8 +10,10 @@
 ## This module contains the data structures for the C code generation phase.
 
 import
-  ast, ropes, options, intsets,
-  tables, ndi, lineinfos, pathutils, modulegraphs, sets
+  ast, ropes, options,
+  ndi, lineinfos, pathutils, modulegraphs
+
+import std/[intsets, tables, sets]
 
 type
   TLabel* = Rope              # for the C generator a label is just a rope
@@ -135,6 +137,7 @@ type
                             # unconditionally...
                             # nimtvDeps is VERY hard to cache because it's
                             # not a list of IDs nor can it be made to be one.
+    mangledPrcs*: HashSet[string]
 
   TCGen = object of PPassContext # represents a C source file
     s*: TCFileSections        # sections of the C file
@@ -148,7 +151,7 @@ type
     typeABICache*: HashSet[SigHash] # cache for ABI checks; reusing typeCache
                               # would be ideal but for some reason enums
                               # don't seem to get cached so it'd generate
-                              # 1 ABI check per occurence in code
+                              # 1 ABI check per occurrence in code
     forwTypeCache*: TypeCache # cache for forward declarations of types
     declaredThings*: IntSet   # things we have declared in this .c file
     declaredProtos*: IntSet   # prototypes we have declared in this .c file
@@ -193,15 +196,17 @@ proc initBlock*(): TBlock =
     result.sections[i] = newRopeAppender()
 
 proc newProc*(prc: PSym, module: BModule): BProc =
-  new(result)
-  result.prc = prc
-  result.module = module
-  result.options = if prc != nil: prc.options
-                   else: module.config.options
-  result.blocks = @[initBlock()]
-  result.nestedTryStmts = @[]
-  result.finallySafePoints = @[]
-  result.sigConflicts = initCountTable[string]()
+  result = BProc(
+    prc: prc,
+    module: module,
+    optionsStack: if module.initProc != nil: module.initProc.optionsStack
+                  else: @[],
+    options: if prc != nil: prc.options
+             else: module.config.options,
+    blocks: @[initBlock()],
+    sigConflicts: initCountTable[string]())
+  if optQuirky in result.options:
+    result.flags = {nimErrorFlagDisabled}
 
 proc newModuleList*(g: ModuleGraph): BModuleList =
   BModuleList(typeInfoMarker: initTable[SigHash, tuple[str: Rope, owner: int32]](),

compiler/cgmeth.nim

@@ -10,12 +10,15 @@
 ## This module implements code generation for methods.
 
 import
-  intsets, options, ast, msgs, idents, renderer, types, magicsys,
-  sempass2, modulegraphs, lineinfos
+  options, ast, msgs, idents, renderer, types, magicsys,
+  sempass2, modulegraphs, lineinfos, astalgo
+
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
+import std/[tables]
 
 proc genConv(n: PNode, d: PType, downcast: bool; conf: ConfigRef): PNode =
   var dest = skipTypes(d, abstractPtrs)
@@ -44,6 +47,8 @@ proc getDispatcher*(s: PSym): PSym =
   if dispatcherPos < s.ast.len:
     result = s.ast[dispatcherPos].sym
     doAssert sfDispatcher in result.flags
+  else:
+    result = nil
 
 proc methodCall*(n: PNode; conf: ConfigRef): PNode =
   result = n
@@ -62,22 +67,25 @@ type
   MethodResult = enum No, Invalid, Yes
 
 proc sameMethodBucket(a, b: PSym; multiMethods: bool): MethodResult =
+  result = No
   if a.name.id != b.name.id: return
-  if a.typ.len != b.typ.len:
+  if a.typ.signatureLen != b.typ.signatureLen:
     return
 
-  for i in 1..<a.typ.len:
-    var aa = a.typ[i]
-    var bb = b.typ[i]
+  var i = 0
+  for x, y in paramTypePairs(a.typ, b.typ):
+    inc i
+    var aa = x
+    var bb = y
     while true:
       aa = skipTypes(aa, {tyGenericInst, tyAlias})
       bb = skipTypes(bb, {tyGenericInst, tyAlias})
       if aa.kind == bb.kind and aa.kind in {tyVar, tyPtr, tyRef, tyLent, tySink}:
-        aa = aa.lastSon
-        bb = bb.lastSon
+        aa = aa.elementType
+        bb = bb.elementType
       else:
         break
-    if sameType(a.typ[i], b.typ[i]):
+    if sameType(x, y):
       if aa.kind == tyObject and result != Invalid:
         result = Yes
     elif aa.kind == tyObject and bb.kind == tyObject and (i == 1 or multiMethods):
@@ -95,10 +103,11 @@ proc sameMethodBucket(a, b: PSym; multiMethods: bool): MethodResult =
       return No
   if result == Yes:
     # check for return type:
-    if not sameTypeOrNil(a.typ[0], b.typ[0]):
-      if b.typ[0] != nil and b.typ[0].kind == tyUntyped:
+    # ignore flags of return types; # bug #22673
+    if not sameTypeOrNil(a.typ.returnType, b.typ.returnType, {IgnoreFlags}):
+      if b.typ.returnType != nil and b.typ.returnType.kind == tyUntyped:
         # infer 'auto' from the base to make it consistent:
-        b.typ[0] = a.typ[0]
+        b.typ.setReturnType a.typ.returnType
       else:
         return No
 
@@ -113,11 +122,11 @@ proc attachDispatcher(s: PSym, dispatcher: PNode) =
     s.ast[dispatcherPos] = dispatcher
 
 proc createDispatcher(s: PSym; g: ModuleGraph; idgen: IdGenerator): PSym =
-  var disp = copySym(s, nextSymId(idgen))
+  var disp = copySym(s, idgen)
   incl(disp.flags, sfDispatcher)
   excl(disp.flags, sfExported)
   let old = disp.typ
-  disp.typ = copyType(disp.typ, nextTypeId(idgen), disp.typ.owner)
+  disp.typ = copyType(disp.typ, idgen, disp.typ.owner)
   copyTypeProps(g, idgen.module, disp.typ, old)
 
   # we can't inline the dispatcher itself (for now):
@@ -125,9 +134,9 @@ proc createDispatcher(s: PSym; g: ModuleGraph; idgen: IdGenerator): PSym =
   disp.ast = copyTree(s.ast)
   disp.ast[bodyPos] = newNodeI(nkEmpty, s.info)
   disp.loc.r = ""
-  if s.typ[0] != nil:
+  if s.typ.returnType != nil:
     if disp.ast.len > resultPos:
-      disp.ast[resultPos].sym = copySym(s.ast[resultPos].sym, nextSymId(idgen))
+      disp.ast[resultPos].sym = copySym(s.ast[resultPos].sym, idgen)
     else:
       # We've encountered a method prototype without a filled-in
       # resultPos slot. We put a placeholder in there that will
@@ -149,7 +158,15 @@ proc fixupDispatcher(meth, disp: PSym; conf: ConfigRef) =
     disp.ast[resultPos] = copyTree(meth.ast[resultPos])
 
 proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
-  var witness: 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"):
+    localError(g.config, s.info, errGenerated, "method `" & s.name.s &
+          "` can be defined only in the same module with its type (" & s.typ.firstParamType.typeToString() & ")")
+  if sfImportc in s.flags:
+    localError(g.config, s.info, errGenerated, "method `" & s.name.s &
+          "` is not allowed to have 'importc' pragmas")
+
   for i in 0..<g.methods.len:
     let disp = g.methods[i].dispatcher
     case sameMethodBucket(disp, s, multimethods = optMultiMethods in g.config.globalOptions)
@@ -168,6 +185,11 @@ proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
     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).itemId notin g.bucketTable:
+    g.bucketTable[s.typ.firstParamType.skipTypes(skipPtrs).itemId] = 1
+  else:
+    g.bucketTable.inc(s.typ.firstParamType.skipTypes(skipPtrs).itemId)
   g.methods.add((methods: @[s], dispatcher: createDispatcher(s, g, idgen)))
   #echo "adding ", s.info
   if witness != nil:
@@ -176,8 +198,9 @@ proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
   elif sfBase notin s.flags:
     message(g.config, s.info, warnUseBase)
 
-proc relevantCol(methods: seq[PSym], col: int): bool =
+proc relevantCol*(methods: seq[PSym], col: int): bool =
   # returns true iff the position is relevant
+  result = false
   var t = methods[0].typ[col].skipTypes(skipPtrs)
   if t.kind == tyObject:
     for i in 1..high(methods):
@@ -186,7 +209,8 @@ proc relevantCol(methods: seq[PSym], col: int): bool =
         return true
 
 proc cmpSignatures(a, b: PSym, relevantCols: IntSet): int =
-  for col in 1..<a.typ.len:
+  result = 0
+  for col in FirstParamAt..<a.typ.signatureLen:
     if contains(relevantCols, col):
       var aa = skipTypes(a.typ[col], skipPtrs)
       var bb = skipTypes(b.typ[col], skipPtrs)
@@ -194,7 +218,7 @@ proc cmpSignatures(a, b: PSym, relevantCols: IntSet): int =
       if (d != high(int)) and d != 0:
         return d
 
-proc sortBucket(a: var seq[PSym], relevantCols: IntSet) =
+proc sortBucket*(a: var seq[PSym], relevantCols: IntSet) =
   # we use shellsort here; fast and simple
   var n = a.len
   var h = 1
@@ -213,16 +237,16 @@ proc sortBucket(a: var seq[PSym], relevantCols: IntSet) =
       a[j] = v
     if h == 1: break
 
-proc genDispatcher(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet): PSym =
+proc genIfDispatcher*(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet; idgen: IdGenerator): PSym =
   var base = methods[0].ast[dispatcherPos].sym
   result = base
-  var paramLen = base.typ.len
+  var paramLen = base.typ.signatureLen
   var nilchecks = newNodeI(nkStmtList, base.info)
   var disp = newNodeI(nkIfStmt, base.info)
   var ands = getSysMagic(g, unknownLineInfo, "and", mAnd)
   var iss = getSysMagic(g, unknownLineInfo, "of", mOf)
   let boolType = getSysType(g, unknownLineInfo, tyBool)
-  for col in 1..<paramLen:
+  for col in FirstParamAt..<paramLen:
     if contains(relevantCols, col):
       let param = base.typ.n[col].sym
       if param.typ.skipTypes(abstractInst).kind in {tyRef, tyPtr}:
@@ -231,7 +255,7 @@ proc genDispatcher(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet): PS
   for meth in 0..high(methods):
     var curr = methods[meth]      # generate condition:
     var cond: PNode = nil
-    for col in 1..<paramLen:
+    for col in FirstParamAt..<paramLen:
       if contains(relevantCols, col):
         var isn = newNodeIT(nkCall, base.info, boolType)
         isn.add newSymNode(iss)
@@ -246,7 +270,7 @@ proc genDispatcher(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet): PS
           cond = a
         else:
           cond = isn
-    let retTyp = base.typ[0]
+    let retTyp = base.typ.returnType
     let call = newNodeIT(nkCall, base.info, retTyp)
     call.add newSymNode(curr)
     for col in 1..<paramLen:
@@ -272,14 +296,13 @@ proc genDispatcher(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet): PS
   nilchecks.flags.incl nfTransf # should not be further transformed
   result.ast[bodyPos] = nilchecks
 
-proc generateMethodDispatchers*(g: ModuleGraph): PNode =
-  result = newNode(nkStmtList)
+proc generateIfMethodDispatchers*(g: ModuleGraph, idgen: IdGenerator) =
   for bucket in 0..<g.methods.len:
     var relevantCols = initIntSet()
-    for col in 1..<g.methods[bucket].methods[0].typ.len:
+    for col in FirstParamAt..<g.methods[bucket].methods[0].typ.signatureLen:
       if relevantCol(g.methods[bucket].methods, col): incl(relevantCols, col)
       if optMultiMethods notin g.config.globalOptions:
         # if multi-methods are not enabled, we are interested only in the first field
         break
     sortBucket(g.methods[bucket].methods, relevantCols)
-    result.add newSymNode(genDispatcher(g, g.methods[bucket].methods, relevantCols))
+    g.addDispatchers genIfDispatcher(g, g.methods[bucket].methods, relevantCols, idgen)

compiler/closureiters.nim

@@ -18,7 +18,8 @@
 #    dec a
 #
 # Should be transformed to:
-#  STATE0:
+#  case :state
+#  of 0:
 #    if a > 0:
 #      echo "hi"
 #      :state = 1 # Next state
@@ -26,12 +27,14 @@
 #    else:
 #      :state = 2 # Next state
 #      break :stateLoop # Proceed to the next state
-#  STATE1:
+#  of 1:
 #    dec a
 #    :state = 0 # Next state
 #    break :stateLoop # Proceed to the next state
-#  STATE2:
+#  of 2:
 #    :state = -1 # End of execution
+#  else:
+#    return
 
 # The transformation should play well with lambdalifting, however depending
 # on situation, it can be called either before or after lambdalifting
@@ -104,12 +107,13 @@
 # Is transformed to (yields are left in place for example simplicity,
 #    in reality the code is subdivided even more, as described above):
 #
-# STATE0: # Try
+# case :state
+# of 0: # Try
 #   yield 0
 #   raise ...
 #   :state = 2 # What would happen should we not raise
 #   break :stateLoop
-# STATE1: # Except
+# of 1: # Except
 #   yield 1
 #   :tmpResult = 3           # Return
 #   :unrollFinally = true # Return
@@ -117,7 +121,7 @@
 #   break :stateLoop
 #   :state = 2 # What would happen should we not return
 #   break :stateLoop
-# STATE2: # Finally
+# of 2: # Finally
 #   yield 2
 #   if :unrollFinally: # This node is created by `newEndFinallyNode`
 #     if :curExc.isNil:
@@ -130,11 +134,15 @@
 #       raise
 #   state = -1 # Goto next state. In this case we just exit
 #   break :stateLoop
+# else:
+#   return
 
 import
   ast, msgs, idents,
   renderer, magicsys, lowerings, lambdalifting, modulegraphs, lineinfos,
-  tables, options
+  options
+
+import std/tables
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -148,7 +156,7 @@ type
     unrollFinallySym: PSym # Indicates that we're unrolling finally states (either exception happened or premature return)
     curExcSym: PSym # Current exception
 
-    states: seq[PNode] # The resulting states. Every state is an nkState node.
+    states: seq[tuple[label: int, body: PNode]] # The resulting states.
     blockLevel: int # Temp used to transform break and continue stmts
     stateLoopLabel: PSym # Label to break on, when jumping between states.
     exitStateIdx: int # index of the last state
@@ -164,6 +172,7 @@ type
 const
   nkSkip = {nkEmpty..nkNilLit, nkTemplateDef, nkTypeSection, nkStaticStmt,
             nkCommentStmt, nkMixinStmt, nkBindStmt} + procDefs
+  emptyStateLabel = -1
 
 proc newStateAccess(ctx: var Ctx): PNode =
   if ctx.stateVarSym.isNil:
@@ -183,8 +192,9 @@ proc newStateAssgn(ctx: var Ctx, stateNo: int = -2): PNode =
   ctx.newStateAssgn(newIntTypeNode(stateNo, ctx.g.getSysType(TLineInfo(), tyInt)))
 
 proc newEnvVar(ctx: var Ctx, name: string, typ: PType): PSym =
-  result = newSym(skVar, getIdent(ctx.g.cache, name), nextSymId(ctx.idgen), ctx.fn, ctx.fn.info)
+  result = newSym(skVar, getIdent(ctx.g.cache, name), ctx.idgen, ctx.fn, ctx.fn.info)
   result.typ = typ
+  result.flags.incl sfNoInit
   assert(not typ.isNil)
 
   if not ctx.stateVarSym.isNil:
@@ -196,7 +206,7 @@ proc newEnvVar(ctx: var Ctx, name: string, typ: PType): PSym =
   else:
     let envParam = getEnvParam(ctx.fn)
     # let obj = envParam.typ.lastSon
-    result = addUniqueField(envParam.typ.lastSon, result, ctx.g.cache, ctx.idgen)
+    result = addUniqueField(envParam.typ.elementType, result, ctx.g.cache, ctx.idgen)
 
 proc newEnvVarAccess(ctx: Ctx, s: PSym): PNode =
   if ctx.stateVarSym.isNil:
@@ -206,7 +216,7 @@ proc newEnvVarAccess(ctx: Ctx, s: PSym): PNode =
 
 proc newTmpResultAccess(ctx: var Ctx): PNode =
   if ctx.tmpResultSym.isNil:
-    ctx.tmpResultSym = ctx.newEnvVar(":tmpResult", ctx.fn.typ[0])
+    ctx.tmpResultSym = ctx.newEnvVar(":tmpResult", ctx.fn.typ.returnType)
   ctx.newEnvVarAccess(ctx.tmpResultSym)
 
 proc newUnrollFinallyAccess(ctx: var Ctx, info: TLineInfo): PNode =
@@ -226,10 +236,7 @@ proc newState(ctx: var Ctx, n, gotoOut: PNode): int =
 
   result = ctx.states.len
   let resLit = ctx.g.newIntLit(n.info, result)
-  let s = newNodeI(nkState, n.info)
-  s.add(resLit)
-  s.add(n)
-  ctx.states.add(s)
+  ctx.states.add((result, n))
   ctx.exceptionTable.add(ctx.curExcHandlingState)
 
   if not gotoOut.isNil:
@@ -258,10 +265,11 @@ proc hasYields(n: PNode): bool =
   of nkYieldStmt:
     result = true
   of nkSkip:
-    discard
+    result = false
   else:
-    for c in n:
-      if c.hasYields:
+    result = false
+    for i in ord(n.kind == nkCast)..<n.len:
+      if n[i].hasYields:
         result = true
         break
 
@@ -325,7 +333,7 @@ proc collectExceptState(ctx: var Ctx, n: PNode): PNode {.inline.} =
       var ifBranch: PNode
 
       if c.len > 1:
-        var cond: PNode
+        var cond: PNode = nil
         for i in 0..<c.len - 1:
           assert(c[i].kind == nkType)
           let nextCond = newTree(nkCall,
@@ -388,26 +396,29 @@ proc getFinallyNode(ctx: var Ctx, n: PNode): PNode =
 proc hasYieldsInExpressions(n: PNode): bool =
   case n.kind
   of nkSkip:
-    discard
+    result = false
   of nkStmtListExpr:
     if isEmptyType(n.typ):
+      result = false
       for c in n:
         if c.hasYieldsInExpressions:
           return true
     else:
       result = n.hasYields
   of nkCast:
+    result = false
     for i in 1..<n.len:
       if n[i].hasYieldsInExpressions:
         return true
   else:
+    result = false
     for c in n:
       if c.hasYieldsInExpressions:
         return true
 
 proc exprToStmtList(n: PNode): tuple[s, res: PNode] =
   assert(n.kind == nkStmtListExpr)
-  result.s = newNodeI(nkStmtList, n.info)
+  result = (newNodeI(nkStmtList, n.info), nil)
   result.s.sons = @[]
 
   var n = n
@@ -442,6 +453,10 @@ proc newNotCall(g: ModuleGraph; e: PNode): PNode =
   result = newTree(nkCall, newSymNode(g.getSysMagic(e.info, "not", mNot), e.info), e)
   result.typ = g.getSysType(e.info, tyBool)
 
+proc boolLit(g: ModuleGraph; info: TLineInfo; value: bool): PNode =
+  result = newIntLit(g, info, ord value)
+  result.typ = getSysType(g, info, tyBool)
+
 proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
   result = n
   case n.kind
@@ -495,7 +510,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
 
     if ns:
       needsSplit = true
-      var tmp: PSym
+      var tmp: PSym = nil
       let isExpr = not isEmptyType(n.typ)
       if isExpr:
         tmp = ctx.newTempVar(n.typ)
@@ -773,7 +788,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
         let check = newTree(nkIfStmt, branch)
         let newBody = newTree(nkStmtList, st, check, n[1])
 
-        n[0] = newSymNode(ctx.g.getSysSym(n[0].info, "true"))
+        n[0] = ctx.g.boolLit(n[0].info, true)
         n[1] = newBody
 
   of nkDotExpr, nkCheckedFieldExpr:
@@ -825,7 +840,7 @@ proc newEndFinallyNode(ctx: var Ctx, info: TLineInfo): PNode =
   let retStmt =
     if ctx.nearestFinally == 0:
       # last finally, we can return
-      let retValue = if ctx.fn.typ[0].isNil:
+      let retValue = if ctx.fn.typ.returnType.isNil:
                    ctx.g.emptyNode
                  else:
                    newTree(nkFastAsgn,
@@ -855,7 +870,9 @@ proc transformReturnsInTry(ctx: var Ctx, n: PNode): PNode =
   case n.kind
   of nkReturnStmt:
     # We're somewhere in try, transform to finally unrolling
-    assert(ctx.nearestFinally != 0)
+    if ctx.nearestFinally == 0:
+      # return is within the finally
+      return
 
     result = newNodeI(nkStmtList, n.info)
 
@@ -1125,10 +1142,10 @@ proc skipEmptyStates(ctx: Ctx, stateIdx: int): int =
     let label = stateIdx
     if label == ctx.exitStateIdx: break
     var newLabel = label
-    if label == -1:
+    if label == emptyStateLabel:
       newLabel = ctx.exitStateIdx
     else:
-      let fs = skipStmtList(ctx, ctx.states[label][1])
+      let fs = skipStmtList(ctx, ctx.states[label].body)
       if fs.kind == nkGotoState:
         newLabel = fs[0].intVal.int
     if label == newLabel: break
@@ -1137,7 +1154,7 @@ proc skipEmptyStates(ctx: Ctx, stateIdx: int): int =
     if maxJumps == 0:
       assert(false, "Internal error")
 
-  result = ctx.states[stateIdx][0].intVal.int
+  result = ctx.states[stateIdx].label
 
 proc skipThroughEmptyStates(ctx: var Ctx, n: PNode): PNode=
   result = n
@@ -1152,9 +1169,9 @@ proc skipThroughEmptyStates(ctx: var Ctx, n: PNode): PNode=
       n[i] = ctx.skipThroughEmptyStates(n[i])
 
 proc newArrayType(g: ModuleGraph; n: int, t: PType; idgen: IdGenerator; owner: PSym): PType =
-  result = newType(tyArray, nextTypeId(idgen), owner)
+  result = newType(tyArray, idgen, owner)
 
-  let rng = newType(tyRange, nextTypeId(idgen), owner)
+  let rng = newType(tyRange, idgen, owner)
   rng.n = newTree(nkRange, g.newIntLit(owner.info, 0), g.newIntLit(owner.info, n - 1))
   rng.rawAddSon(t)
 
@@ -1255,11 +1272,10 @@ proc wrapIntoTryExcept(ctx: var Ctx, n: PNode): PNode {.inline.} =
 proc wrapIntoStateLoop(ctx: var Ctx, n: PNode): PNode =
   # while true:
   #   block :stateLoop:
-  #     gotoState :state
   #     local vars decl (if needed)
   #     body # Might get wrapped in try-except
   let loopBody = newNodeI(nkStmtList, n.info)
-  result = newTree(nkWhileStmt, newSymNode(ctx.g.getSysSym(n.info, "true")), loopBody)
+  result = newTree(nkWhileStmt, ctx.g.boolLit(n.info, true), loopBody)
   result.info = n.info
 
   let localVars = newNodeI(nkStmtList, n.info)
@@ -1274,11 +1290,7 @@ proc wrapIntoStateLoop(ctx: var Ctx, n: PNode): PNode =
   let blockStmt = newNodeI(nkBlockStmt, n.info)
   blockStmt.add(newSymNode(ctx.stateLoopLabel))
 
-  let gs = newNodeI(nkGotoState, n.info)
-  gs.add(ctx.newStateAccess())
-  gs.add(ctx.g.newIntLit(n.info, ctx.states.len - 1))
-
-  var blockBody = newTree(nkStmtList, gs, localVars, n)
+  var blockBody = newTree(nkStmtList, localVars, n)
   if ctx.hasExceptions:
     blockBody = ctx.wrapIntoTryExcept(blockBody)
 
@@ -1291,29 +1303,28 @@ proc deleteEmptyStates(ctx: var Ctx) =
 
   # Apply new state indexes and mark unused states with -1
   var iValid = 0
-  for i, s in ctx.states:
-    let body = skipStmtList(ctx, s[1])
+  for i, s in ctx.states.mpairs:
+    let body = skipStmtList(ctx, s.body)
     if body.kind == nkGotoState and i != ctx.states.len - 1 and i != 0:
       # This is an empty state. Mark with -1.
-      s[0].intVal = -1
+      s.label = emptyStateLabel
     else:
-      s[0].intVal = iValid
+      s.label = iValid
       inc iValid
 
   for i, s in ctx.states:
-    let body = skipStmtList(ctx, s[1])
+    let body = skipStmtList(ctx, s.body)
     if body.kind != nkGotoState or i == 0:
-      discard ctx.skipThroughEmptyStates(s)
+      discard ctx.skipThroughEmptyStates(s.body)
       let excHandlState = ctx.exceptionTable[i]
       if excHandlState < 0:
         ctx.exceptionTable[i] = -ctx.skipEmptyStates(-excHandlState)
       elif excHandlState != 0:
         ctx.exceptionTable[i] = ctx.skipEmptyStates(excHandlState)
 
-  var i = 0
+  var i = 1 # ignore the entry and the exit
   while i < ctx.states.len - 1:
-    let fs = skipStmtList(ctx, ctx.states[i][1])
-    if fs.kind == nkGotoState and i != 0:
+    if ctx.states[i].label == emptyStateLabel:
       ctx.states.delete(i)
       ctx.exceptionTable.delete(i)
     else:
@@ -1348,7 +1359,7 @@ proc freshVars(n: PNode; c: var FreshVarsContext): PNode =
         let idefs = copyNode(it)
         for v in 0..it.len-3:
           if it[v].kind == nkSym:
-            let x = copySym(it[v].sym, nextSymId(c.idgen))
+            let x = copySym(it[v].sym, c.idgen)
             c.tab[it[v].sym.id] = x
             idefs.add newSymNode(x)
           else:
@@ -1359,6 +1370,7 @@ proc freshVars(n: PNode; c: var FreshVarsContext): PNode =
       else:
         result.add it
   of nkRaiseStmt:
+    result = nil
     localError(c.config, c.info, "unsupported control flow: 'finally: ... raise' duplicated because of 'break'")
   else:
     result = n
@@ -1389,7 +1401,7 @@ proc preprocess(c: var PreprocessContext; n: PNode): PNode =
       discard c.finallys.pop()
 
   of nkWhileStmt, nkBlockStmt:
-    if n.hasYields == false: return n
+    if not n.hasYields: return n
     c.blocks.add((n, c.finallys.len))
     for i in 0 ..< n.len:
       result[i] = preprocess(c, n[i])
@@ -1422,18 +1434,15 @@ proc preprocess(c: var PreprocessContext; n: PNode): PNode =
       result[i] = preprocess(c, n[i])
 
 proc transformClosureIterator*(g: ModuleGraph; idgen: IdGenerator; fn: PSym, n: PNode): PNode =
-  var ctx: Ctx
-  ctx.g = g
-  ctx.fn = fn
-  ctx.idgen = idgen
+  var ctx = Ctx(g: g, fn: fn, idgen: idgen)
 
   if getEnvParam(fn).isNil:
     # Lambda lifting was not done yet. Use temporary :state sym, which will
     # be handled specially by lambda lifting. Local temp vars (if needed)
     # should follow the same logic.
-    ctx.stateVarSym = newSym(skVar, getIdent(ctx.g.cache, ":state"), nextSymId(idgen), fn, fn.info)
+    ctx.stateVarSym = newSym(skVar, getIdent(ctx.g.cache, ":state"), idgen, fn, fn.info)
     ctx.stateVarSym.typ = g.createClosureIterStateType(fn, idgen)
-  ctx.stateLoopLabel = newSym(skLabel, getIdent(ctx.g.cache, ":stateLoop"), nextSymId(idgen), fn, fn.info)
+  ctx.stateLoopLabel = newSym(skLabel, getIdent(ctx.g.cache, ":stateLoop"), idgen, fn, fn.info)
   var pc = PreprocessContext(finallys: @[], config: g.config, idgen: idgen)
   var n = preprocess(pc, n.toStmtList)
   #echo "transformed into ", n
@@ -1454,21 +1463,21 @@ proc transformClosureIterator*(g: ModuleGraph; idgen: IdGenerator; fn: PSym, n:
   # Optimize empty states away
   ctx.deleteEmptyStates()
 
-  # Make new body by concatenating the list of states
-  result = newNodeI(nkStmtList, n.info)
+  let caseDispatcher = newTreeI(nkCaseStmt, n.info,
+      ctx.newStateAccess())
+
   for s in ctx.states:
-    assert(s.len == 2)
-    let body = s[1]
-    s.sons.del(1)
-    result.add(s)
-    result.add(body)
+    let body = ctx.transformStateAssignments(s.body)
+    caseDispatcher.add newTreeI(nkOfBranch, body.info, g.newIntLit(body.info, s.label), body)
 
-  result = ctx.transformStateAssignments(result)
-  result = ctx.wrapIntoStateLoop(result)
+  caseDispatcher.add newTreeI(nkElse, n.info, newTreeI(nkReturnStmt, n.info, g.emptyNode))
 
-  # echo "TRANSFORM TO STATES: "
-  # echo renderTree(result)
+  result = wrapIntoStateLoop(ctx, caseDispatcher)
 
-  # echo "exception table:"
-  # for i, e in ctx.exceptionTable:
-  #   echo i, " -> ", e
+  when false:
+    echo "TRANSFORM TO STATES: "
+    echo renderTree(result)
+
+    echo "exception table:"
+    for i, e in ctx.exceptionTable:
+      echo i, " -> ", e

compiler/cmdlinehelper.nim

@@ -7,11 +7,13 @@
 #    distribution, for details about the copyright.
 #
 
-## Helpers for binaries that use compiler passes, e.g.: nim, nimsuggest, nimfix
+## Helpers for binaries that use compiler passes, e.g.: nim, nimsuggest
 
 import
   options, idents, nimconf, extccomp, commands, msgs,
-  lineinfos, modulegraphs, condsyms, os, pathutils, parseopt
+  lineinfos, modulegraphs, condsyms, pathutils
+
+import std/[os, parseopt]
 
 proc prependCurDir*(f: AbsoluteFile): AbsoluteFile =
   when defined(unix):
@@ -55,6 +57,11 @@ proc loadConfigsAndProcessCmdLine*(self: NimProg, cache: IdentCache; conf: Confi
   if conf.cmd == cmdNimscript:
     incl(conf.globalOptions, optWasNimscript)
   loadConfigs(DefaultConfig, cache, conf, graph.idgen) # load all config files
+  # restores `conf.notes` after loading config files
+  # because it has overwrites the notes when compiling the system module which
+  # is a foreign module compared to the project
+  if conf.cmd in cmdBackends:
+    conf.notes = conf.mainPackageNotes
 
   if not self.suggestMode:
     let scriptFile = conf.projectFull.changeFileExt("nims")

compiler/commands.nim

@@ -27,7 +27,9 @@ bootSwitch(usedNoGC, defined(nogc), "--gc:none")
 import std/[setutils, os, strutils, parseutils, parseopt, sequtils, strtabs]
 import
   msgs, options, nversion, condsyms, extccomp, platform,
-  wordrecg, nimblecmd, lineinfos, pathutils, pathnorm
+  wordrecg, nimblecmd, lineinfos, pathutils
+
+import std/pathnorm
 
 from ast import setUseIc, eqTypeFlags, tfGcSafe, tfNoSideEffect
 
@@ -184,7 +186,7 @@ proc processSpecificNote*(arg: string, state: TSpecialWord, pass: TCmdLinePass,
                          info: TLineInfo; orig: string; conf: ConfigRef) =
   var id = ""  # arg = key or [key] or key:val or [key]:val;  with val=on|off
   var i = 0
-  var notes: set[TMsgKind]
+  var notes: set[TMsgKind] = {}
   var isBracket = false
   if i < arg.len and arg[i] == '[':
     isBracket = true
@@ -205,7 +207,11 @@ proc processSpecificNote*(arg: string, state: TSpecialWord, pass: TCmdLinePass,
     # 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: localError(conf, info, "unknown $#: $#" % [name, id])
+    else:
+      if isSomeHint:
+        message(conf, info, hintUnknownHint, id)
+      else:
+        localError(conf, info, "unknown $#: $#" % [name, id])
   case id.normalize
   of "all": # other note groups would be easy to support via additional cases
     notes = if isSomeHint: {hintMin..hintMax} else: {warnMin..warnMax}
@@ -238,9 +244,9 @@ proc processCompile(conf: ConfigRef; filename: string) =
   extccomp.addExternalFileToCompile(conf, found)
 
 const
-  errNoneBoehmRefcExpectedButXFound = "'arc', 'orc', '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' or 'lib' expected, but '$1' found"
+  errGuiConsoleOrLibExpectedButXFound = "'gui', 'console', 'lib' or 'staticlib' expected, but '$1' found"
   errInvalidExceptionSystem = "'goto', 'setjmp', 'cpp' or 'quirky' expected, but '$1' found"
 
 template warningOptionNoop(switch: string) =
@@ -262,13 +268,18 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
     of "go": result = conf.selectedGC == gcGo
     of "none": result = conf.selectedGC == gcNone
     of "stack", "regions": result = conf.selectedGC == gcRegions
-    else: localError(conf, info, errNoneBoehmRefcExpectedButXFound % arg)
+    of "atomicarc": result = conf.selectedGC == gcAtomicArc
+    else:
+      result = false
+      localError(conf, info, errNoneBoehmRefcExpectedButXFound % arg)
   of "opt":
     case arg.normalize
     of "speed": result = contains(conf.options, optOptimizeSpeed)
     of "size": result = contains(conf.options, optOptimizeSize)
     of "none": result = conf.options * {optOptimizeSpeed, optOptimizeSize} == {}
-    else: localError(conf, info, errNoneSpeedOrSizeExpectedButXFound % arg)
+    else:
+      result = false
+      localError(conf, info, errNoneSpeedOrSizeExpectedButXFound % arg)
   of "verbosity": result = $conf.verbosity == arg
   of "app":
     case arg.normalize
@@ -278,7 +289,9 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
                       not contains(conf.globalOptions, optGenGuiApp)
     of "staticlib": result = contains(conf.globalOptions, optGenStaticLib) and
                       not contains(conf.globalOptions, optGenGuiApp)
-    else: localError(conf, info, errGuiConsoleOrLibExpectedButXFound % arg)
+    else:
+      result = false
+      localError(conf, info, errGuiConsoleOrLibExpectedButXFound % arg)
   of "dynliboverride":
     result = isDynlibOverride(conf, arg)
   of "exceptions":
@@ -287,8 +300,12 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
     of "setjmp": result = conf.exc == excSetjmp
     of "quirky": result = conf.exc == excQuirky
     of "goto": result = conf.exc == excGoto
-    else: localError(conf, info, errInvalidExceptionSystem % arg)
-  else: invalidCmdLineOption(conf, passCmd1, switch, info)
+    else:
+      result = false
+      localError(conf, info, errInvalidExceptionSystem % arg)
+  else:
+    result = false
+    invalidCmdLineOption(conf, passCmd1, switch, info)
 
 proc testCompileOption*(conf: ConfigRef; switch: string, info: TLineInfo): bool =
   case switch.normalize
@@ -334,9 +351,14 @@ proc testCompileOption*(conf: ConfigRef; switch: string, info: TLineInfo): bool
     if switch.normalize == "patterns": deprecatedAlias(switch, "trmacros")
     result = contains(conf.options, optTrMacros)
   of "excessivestacktrace": result = contains(conf.globalOptions, optExcessiveStackTrace)
-  of "nilseqs", "nilchecks", "taintmode": warningOptionNoop(switch)
+  of "nilseqs", "nilchecks", "taintmode":
+    warningOptionNoop(switch)
+    result = false
   of "panics": result = contains(conf.globalOptions, optPanics)
-  else: invalidCmdLineOption(conf, passCmd1, switch, info)
+  of "jsbigint64": result = contains(conf.globalOptions, optJsBigInt64)
+  else:
+    result = false
+    invalidCmdLineOption(conf, passCmd1, switch, info)
 
 proc processPath(conf: ConfigRef; path: string, info: TLineInfo,
                  notRelativeToProj = false): AbsoluteDir =
@@ -378,7 +400,8 @@ proc makeAbsolute(s: string): AbsoluteFile =
 proc setTrackingInfo(conf: ConfigRef; dirty, file, line, column: string,
                      info: TLineInfo) =
   ## set tracking info, common code for track, trackDirty, & ideTrack
-  var ln, col: int
+  var ln: int = 0
+  var col: int = 0
   if parseUtils.parseInt(line, ln) <= 0:
     localError(conf, info, errInvalidNumber % line)
   if parseUtils.parseInt(column, col) <= 0:
@@ -439,10 +462,12 @@ proc handleCmdInput*(conf: ConfigRef) =
 proc parseCommand*(command: string): Command =
   case command.normalize
   of "c", "cc", "compile", "compiletoc": cmdCompileToC
+  of "nir": cmdCompileToNir
   of "cpp", "compiletocpp": cmdCompileToCpp
   of "objc", "compiletooc": cmdCompileToOC
   of "js", "compiletojs": cmdCompileToJS
   of "r": cmdCrun
+  of "m": cmdM
   of "run": cmdTcc
   of "check": cmdCheck
   of "e": cmdNimscript
@@ -475,6 +500,7 @@ proc setCmd*(conf: ConfigRef, cmd: Command) =
   of cmdCompileToCpp: conf.backend = backendCpp
   of cmdCompileToOC: conf.backend = backendObjc
   of cmdCompileToJS: conf.backend = backendJs
+  of cmdCompileToNir: conf.backend = backendNir
   else: discard
 
 proc setCommandEarly*(conf: ConfigRef, command: string) =
@@ -515,14 +541,7 @@ proc initOrcDefines*(conf: ConfigRef) =
   if conf.exc == excNone and conf.backend != backendCpp:
     conf.exc = excGoto
 
-proc registerArcOrc(pass: TCmdLinePass, conf: ConfigRef, isOrc: bool) =
-  if isOrc:
-    conf.selectedGC = gcOrc
-    defineSymbol(conf.symbols, "gcorc")
-  else:
-    conf.selectedGC = gcArc
-    defineSymbol(conf.symbols, "gcarc")
-
+proc registerArcOrc(pass: TCmdLinePass, conf: ConfigRef) =
   defineSymbol(conf.symbols, "gcdestructors")
   incl conf.globalOptions, optSeqDestructors
   incl conf.globalOptions, optTinyRtti
@@ -532,10 +551,11 @@ proc registerArcOrc(pass: TCmdLinePass, conf: ConfigRef, isOrc: bool) =
   if conf.exc == excNone and conf.backend != backendCpp:
     conf.exc = excGoto
 
-proc unregisterArcOrc(conf: ConfigRef) =
+proc unregisterArcOrc*(conf: ConfigRef) =
   undefSymbol(conf.symbols, "gcdestructors")
   undefSymbol(conf.symbols, "gcarc")
   undefSymbol(conf.symbols, "gcorc")
+  undefSymbol(conf.symbols, "gcatomicarc")
   undefSymbol(conf.symbols, "nimSeqsV2")
   undefSymbol(conf.symbols, "nimV2")
   excl conf.globalOptions, optSeqDestructors
@@ -561,9 +581,17 @@ proc processMemoryManagementOption(switch, arg: string, pass: TCmdLinePass,
       conf.selectedGC = gcMarkAndSweep
       defineSymbol(conf.symbols, "gcmarkandsweep")
     of "destructors", "arc":
-      registerArcOrc(pass, conf, false)
+      conf.selectedGC = gcArc
+      defineSymbol(conf.symbols, "gcarc")
+      registerArcOrc(pass, conf)
     of "orc":
-      registerArcOrc(pass, conf, true)
+      conf.selectedGC = gcOrc
+      defineSymbol(conf.symbols, "gcorc")
+      registerArcOrc(pass, conf)
+    of "atomicarc":
+      conf.selectedGC = gcAtomicArc
+      defineSymbol(conf.symbols, "gcatomicarc")
+      registerArcOrc(pass, conf)
     of "hooks":
       conf.selectedGC = gcHooks
       defineSymbol(conf.symbols, "gchooks")
@@ -585,10 +613,17 @@ proc processMemoryManagementOption(switch, arg: string, pass: TCmdLinePass,
       defineSymbol(conf.symbols, "gcregions")
     else: localError(conf, info, errNoneBoehmRefcExpectedButXFound % arg)
 
+proc pathRelativeToConfig(arg: string, pass: TCmdLinePass, conf: ConfigRef): string =
+  if pass == passPP and not isAbsolute(arg):
+    assert isAbsolute(conf.currentConfigDir), "something is wrong with currentConfigDir"
+    result = conf.currentConfigDir / arg
+  else:
+    result = arg
+
 proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
                     conf: ConfigRef) =
-  var
-    key, val: string
+  var key = ""
+  var val = ""
   case switch.normalize
   of "eval":
     expectArg(conf, switch, arg, pass, info)
@@ -603,17 +638,17 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     for path in nimbleSubs(conf, arg):
       addPath(conf, if pass == passPP: processCfgPath(conf, path, info)
                     else: processPath(conf, path, info), info)
-  of "nimblepath", "babelpath":
-    if switch.normalize == "babelpath": deprecatedAlias(switch, "nimblepath")
+  of "nimblepath":
     if pass in {passCmd2, passPP} and optNoNimblePath notin conf.globalOptions:
       expectArg(conf, switch, arg, pass, info)
       var path = processPath(conf, arg, info, notRelativeToProj=true)
       let nimbleDir = AbsoluteDir getEnv("NIMBLE_DIR")
       if not nimbleDir.isEmpty and pass == passPP:
+        path = nimbleDir / RelativeDir"pkgs2"
+        nimblePath(conf, path, info)
         path = nimbleDir / RelativeDir"pkgs"
       nimblePath(conf, path, info)
-  of "nonimblepath", "nobabelpath":
-    if switch.normalize == "nobabelpath": deprecatedAlias(switch, "nonimblepath")
+  of "nonimblepath":
     expectNoArg(conf, switch, arg, pass, info)
     disableNimblePath(conf)
   of "clearnimblepath":
@@ -630,7 +665,7 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     # refs bug #18674, otherwise `--os:windows` messes up with `--nimcache` set
     # in config nims files, e.g. via: `import os; switch("nimcache", "/tmp/somedir")`
     if conf.target.targetOS == osWindows and DirSep == '/': arg = arg.replace('\\', '/')
-    conf.nimcacheDir = processPath(conf, arg, info, notRelativeToProj=true)
+    conf.nimcacheDir = processPath(conf, pathRelativeToConfig(arg, pass, conf), info, notRelativeToProj=true)
   of "out", "o":
     expectArg(conf, switch, arg, pass, info)
     let f = splitFile(processPath(conf, arg, info, notRelativeToProj=true).string)
@@ -651,6 +686,9 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     if backend == TBackend.default: localError(conf, info, "invalid backend: '$1'" % arg)
     if backend == backendJs: # bug #21209
       conf.globalOptions.excl {optThreadAnalysis, optThreads}
+      if optRun in conf.globalOptions:
+        # for now, -r uses nodejs, so define nodejs
+        defineSymbol(conf.symbols, "nodejs")
     conf.backend = backend
   of "doccmd": conf.docCmd = arg
   of "define", "d":
@@ -761,7 +799,10 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     if conf.backend == backendJs or conf.cmd == cmdNimscript: discard
     else: processOnOffSwitchG(conf, {optThreads}, arg, pass, info)
     #if optThreads in conf.globalOptions: conf.setNote(warnGcUnsafe)
-  of "tlsemulation": processOnOffSwitchG(conf, {optTlsEmulation}, arg, pass, info)
+  of "tlsemulation":
+    processOnOffSwitchG(conf, {optTlsEmulation}, arg, pass, info)
+    if optTlsEmulation in conf.globalOptions:
+      conf.legacyFeatures.incl emitGenerics
   of "implicitstatic":
     processOnOffSwitch(conf, {optImplicitStatic}, arg, pass, info)
   of "patterns", "trmacros":
@@ -798,6 +839,7 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
       defineSymbol(conf.symbols, "dll")
     of "staticlib":
       incl(conf.globalOptions, optGenStaticLib)
+      incl(conf.globalOptions, optNoMain)
       excl(conf.globalOptions, optGenGuiApp)
       defineSymbol(conf.symbols, "library")
       defineSymbol(conf.symbols, "staticlib")
@@ -821,6 +863,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
   of "header":
     if conf != nil: conf.headerFile = arg
     incl(conf.globalOptions, optGenIndex)
+  of "nimbasepattern":
+    if conf != nil: conf.nimbasePattern = arg
   of "index":
     case arg.normalize
     of "", "on": conf.globalOptions.incl {optGenIndex}
@@ -861,21 +905,28 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
       setTarget(conf.target, conf.target.targetOS, cpu)
   of "run", "r":
     processOnOffSwitchG(conf, {optRun}, arg, pass, info)
+    if conf.backend == backendJs:
+      # for now, -r uses nodejs, so define nodejs
+      defineSymbol(conf.symbols, "nodejs")
   of "maxloopiterationsvm":
     expectArg(conf, switch, arg, pass, info)
-    conf.maxLoopIterationsVM = parseInt(arg)
+    var value: int = 10_000_000
+    discard parseSaturatedNatural(arg, value)
+    if not value > 0: localError(conf, info, "maxLoopIterationsVM must be a positive integer greater than zero")
+    conf.maxLoopIterationsVM = value
   of "errormax":
     expectArg(conf, switch, arg, pass, info)
     # Note: `nim check` (etc) can overwrite this.
     # `0` is meaningless, give it a useful meaning as in clang's -ferror-limit
     # If user doesn't set this flag and the code doesn't either, it'd
     # have the same effect as errorMax = 1
-    let ret = parseInt(arg)
-    conf.errorMax = if ret == 0: high(int) else: ret
+    var value: int = 0
+    discard parseSaturatedNatural(arg, value)
+    conf.errorMax = if value == 0: high(int) else: value
   of "verbosity":
     expectArg(conf, switch, arg, pass, info)
     let verbosity = parseInt(arg)
-    if verbosity notin {0..3}:
+    if verbosity notin 0..3:
       localError(conf, info, "invalid verbosity level: '$1'" % arg)
     conf.verbosity = verbosity
     var verb = NotesVerbosity[conf.verbosity]
@@ -885,7 +936,9 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     conf.mainPackageNotes = conf.notes
   of "parallelbuild":
     expectArg(conf, switch, arg, pass, info)
-    conf.numberOfProcessors = parseInt(arg)
+    var value: int = 0
+    discard parseSaturatedNatural(arg, value)
+    conf.numberOfProcessors = value
   of "version", "v":
     expectNoArg(conf, switch, arg, pass, info)
     writeVersionInfo(conf, pass)
@@ -1065,29 +1118,6 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
   of "expandarc":
     expectArg(conf, switch, arg, pass, info)
     conf.arcToExpand[arg] = "T"
-  of "useversion":
-    expectArg(conf, switch, arg, pass, info)
-    case arg
-    of "1.0":
-      defineSymbol(conf.symbols, "NimMajor", "1")
-      defineSymbol(conf.symbols, "NimMinor", "0")
-      # old behaviors go here:
-      defineSymbol(conf.symbols, "nimOldRelativePathBehavior")
-      undefSymbol(conf.symbols, "nimDoesntTrackDefects")
-      ast.eqTypeFlags.excl {tfGcSafe, tfNoSideEffect}
-      conf.globalOptions.incl optNimV1Emulation
-    of "1.2":
-      defineSymbol(conf.symbols, "NimMajor", "1")
-      defineSymbol(conf.symbols, "NimMinor", "2")
-      conf.globalOptions.incl optNimV12Emulation
-    of "1.6":
-      defineSymbol(conf.symbols, "NimMajor", "1")
-      defineSymbol(conf.symbols, "NimMinor", "6")
-      conf.globalOptions.incl optNimV16Emulation
-    else:
-      localError(conf, info, "unknown Nim version; currently supported values are: `1.0`, `1.2`")
-    # always be compatible with 1.x.100:
-    defineSymbol(conf.symbols, "NimPatch", "100")
   of "benchmarkvm":
     processOnOffSwitchG(conf, {optBenchmarkVM}, arg, pass, info)
   of "profilevm":
@@ -1101,6 +1131,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     processOnOffSwitchG(conf, {optPanics}, arg, pass, info)
     if optPanics in conf.globalOptions:
       defineSymbol(conf.symbols, "nimPanics")
+  of "jsbigint64":
+    processOnOffSwitchG(conf, {optJsBigInt64}, arg, pass, info)
   of "sourcemap": # xxx document in --fullhelp
     conf.globalOptions.incl optSourcemap
     conf.options.incl optLineDir
@@ -1115,7 +1147,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     else: invalidCmdLineOption(conf, pass, switch, info)
 
 proc processCommand*(switch: string, pass: TCmdLinePass; config: ConfigRef) =
-  var cmd, arg: string
+  var cmd = ""
+  var arg = ""
   splitSwitch(config, switch, cmd, arg, pass, gCmdLineInfo)
   processSwitch(cmd, arg, pass, gCmdLineInfo, config)
 
@@ -1142,7 +1175,10 @@ proc processArgument*(pass: TCmdLinePass; p: OptParser;
       config.projectName = unixToNativePath(p.key)
       config.arguments = cmdLineRest(p)
       result = true
-    elif pass != passCmd2: setCommandEarly(config, p.key)
+    elif pass != passCmd2:
+      setCommandEarly(config, p.key)
+      result = false
+    else: result = false
   else:
     if pass == passCmd1: config.commandArgs.add p.key
     if argsCount == 1:
@@ -1153,4 +1189,6 @@ proc processArgument*(pass: TCmdLinePass; p: OptParser;
         config.projectName = unixToNativePath(p.key)
       config.arguments = cmdLineRest(p)
       result = true
+    else:
+      result = false
   inc argsCount

compiler/compiler.nimble

@@ -0,0 +1,28 @@
+include "../lib/system/compilation.nim"
+version = $NimMajor & "." & $NimMinor & "." & $NimPatch
+author = "Andreas Rumpf"
+description = "Compiler package providing the compiler sources as a library."
+license = "MIT"
+skipDirs = @["."]
+installDirs = @["compiler"]
+
+import os
+
+var compilerDir = ""
+
+before install:
+  rmDir("compiler")
+
+  let
+    files = listFiles(".")
+    dirs = listDirs(".")
+
+  mkDir("compiler")
+
+  for f in files:
+    cpFile(f, "compiler" / f)
+
+  for d in dirs:
+    cpDir(d, "compiler" / d)
+
+requires "nim"

compiler/concepts.nim

@@ -11,9 +11,9 @@
 ## for details. Note this is a first implementation and only the "Concept matching"
 ## section has been implemented.
 
-import ast, astalgo, semdata, lookups, lineinfos, idents, msgs, renderer, types, intsets
+import ast, astalgo, semdata, lookups, lineinfos, idents, msgs, renderer, types
 
-from magicsys import addSonSkipIntLit
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -27,24 +27,12 @@ const
 proc declareSelf(c: PContext; info: TLineInfo) =
   ## Adds the magical 'Self' symbols to the current scope.
   let ow = getCurrOwner(c)
-  let s = newSym(skType, getIdent(c.cache, "Self"), nextSymId(c.idgen), ow, info)
-  s.typ = newType(tyTypeDesc, nextTypeId(c.idgen), ow)
+  let s = newSym(skType, getIdent(c.cache, "Self"), c.idgen, ow, info)
+  s.typ = newType(tyTypeDesc, c.idgen, ow)
   s.typ.flags.incl {tfUnresolved, tfPacked}
-  s.typ.add newType(tyEmpty, nextTypeId(c.idgen), ow)
+  s.typ.add newType(tyEmpty, c.idgen, ow)
   addDecl(c, s, info)
 
-proc isSelf*(t: PType): bool {.inline.} =
-  ## Is this the magical 'Self' type?
-  t.kind == tyTypeDesc and tfPacked in t.flags
-
-proc makeTypeDesc*(c: PContext, typ: PType): PType =
-  if typ.kind == tyTypeDesc and not isSelf(typ):
-    result = typ
-  else:
-    result = newTypeS(tyTypeDesc, c)
-    incl result.flags, tfCheckedForDestructor
-    result.addSonSkipIntLit(typ, c.idgen)
-
 proc semConceptDecl(c: PContext; n: PNode): PNode =
   ## Recursive helper for semantic checking for the concept declaration.
   ## Currently we only support (possibly empty) lists of statements
@@ -62,7 +50,7 @@ proc semConceptDecl(c: PContext; n: PNode): PNode =
       result[i] = n[i]
     result[^1] = semConceptDecl(c, n[^1])
   of nkCommentStmt:
-    discard
+    result = n
   else:
     localError(c.config, n.info, "unexpected construct in the new-styled concept: " & renderTree(n))
     result = n
@@ -108,7 +96,7 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
     ignorableForArgType = {tyVar, tySink, tyLent, tyOwned, tyGenericInst, tyAlias, tyInferred}
   case f.kind
   of tyAlias:
-    result = matchType(c, f.lastSon, a, m)
+    result = matchType(c, f.skipModifier, a, m)
   of tyTypeDesc:
     if isSelf(f):
       #let oldLen = m.inferred.len
@@ -117,15 +105,19 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
       #m.inferred.setLen oldLen
       #echo "A for ", result, " to ", typeToString(a), " to ", typeToString(m.potentialImplementation)
     else:
-      if a.kind == tyTypeDesc and f.len == a.len:
-        for i in 0..<a.len:
-          if not matchType(c, f[i], a[i], m): return false
-        return true
+      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:
-    if a.kind == tyGenericInst and a[0].kind == tyGenericBody:
-      if sameType(f[0], a[0]) and f.len == a.len-1:
-        for i in 1 ..< f.len:
+    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:
@@ -135,17 +127,17 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
     else:
       let old = existingBinding(m, f)
       if old == nil:
-        if f.len > 0 and f[0].kind != tyNone:
+        if f.hasElementType and f.elementType.kind != tyNone:
           # also check the generic's constraints:
           let oldLen = m.inferred.len
-          result = matchType(c, f[0], a, m)
+          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, lastSon ak))
+          m.inferred.add((f, last ak))
           result = true
         else:
           when logBindings: echo "C adding ", f, " ", ak
@@ -156,15 +148,17 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
         result = matchType(c, old, ak, m)
         if m.magic == mArrPut and ak.kind == tyGenericParam:
           result = true
+      else:
+        result = false
     #echo "B for ", result, " to ", typeToString(a), " to ", typeToString(m.potentialImplementation)
 
   of tyVar, tySink, tyLent, tyOwned:
     # modifiers in the concept must be there in the actual implementation
     # too but not vice versa.
     if a.kind == f.kind:
-      result = matchType(c, f.sons[0], a.sons[0], m)
+      result = matchType(c, f.elementType, a.elementType, m)
     elif m.magic == mArrPut:
-      result = matchType(c, f.sons[0], a, m)
+      result = matchType(c, f.elementType, a, m)
     else:
       result = false
   of tyEnum, tyObject, tyDistinct:
@@ -174,7 +168,7 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
   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.len > 0 and ak[0].kind == tyOrdinal)
+       (ak.kind == tyGenericParam and ak.hasElementType and ak.elementType.kind == tyOrdinal)
   of tyConcept:
     let oldLen = m.inferred.len
     let oldPotentialImplementation = m.potentialImplementation
@@ -185,9 +179,11 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
       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 ak = a.skipTypes(ignorableForArgType - {f.kind})
-    if ak.kind == f.kind and f.len == ak.len:
-      for i in 0..<ak.len:
+    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:
@@ -196,29 +192,30 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
       # say the concept requires 'int|float|string' if the potentialImplementation
       # says 'int|string' that is good enough.
       var covered = 0
-      for i in 0..<f.len:
-        for j in 0..<a.len:
+      for ff in f.kids:
+        for aa in a.kids:
           let oldLenB = m.inferred.len
-          let r = matchType(c, f[i], a[j], m)
+          let r = matchType(c, ff, aa, m)
           if r:
             inc covered
             break
           m.inferred.setLen oldLenB
 
-      result = covered >= a.len
+      result = covered >= a.kidsLen
       if not result:
         m.inferred.setLen oldLen
     else:
-      for i in 0..<f.len:
-        result = matchType(c, f[i], a, m)
+      result = false
+      for ff in f.kids:
+        result = matchType(c, ff, a, m)
         if result: break # and remember the binding!
         m.inferred.setLen oldLen
   of tyNot:
     if a.kind == tyNot:
-      result = matchType(c, f[0], a[0], m)
+      result = matchType(c, f.elementType, a.elementType, m)
     else:
       let oldLen = m.inferred.len
-      result = not matchType(c, f[0], a, m)
+      result = not matchType(c, f.elementType, a, m)
       m.inferred.setLen oldLen
   of tyAnything:
     result = true
@@ -257,7 +254,7 @@ proc matchSym(c: PContext; candidate: PSym, n: PNode; m: var MatchCon): bool =
       m.inferred.setLen oldLen
       return false
 
-  if not matchReturnType(c, n[0].sym.typ.sons[0], candidate.typ.sons[0], m):
+  if not matchReturnType(c, n[0].sym.typ.returnType, candidate.typ.returnType, m):
     m.inferred.setLen oldLen
     return false
 
@@ -306,13 +303,15 @@ proc conceptMatchNode(c: PContext; n: PNode; m: var MatchCon): bool =
     result = matchSyms(c, n, {skMethod}, m)
   of nkIteratorDef:
     result = matchSyms(c, n, {skIterator}, m)
+  of nkCommentStmt:
+    result = true
   else:
     # error was reported earlier.
     result = false
 
-proc conceptMatch*(c: PContext; concpt, arg: PType; bindings: var TIdTable; invocation: PType): 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 fullfill the
+  ## 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
   ## (typeVar, instance) pairs. ('typeVar' is usually simply written as a generic 'T'.)
   ## 'invocation' can be nil for atomic concepts. For non-atomic concepts, it contains the
@@ -337,8 +336,8 @@ proc conceptMatch*(c: PContext; concpt, arg: PType; bindings: var TIdTable; invo
     # we have a match, so bind 'arg' itself to 'concpt':
     bindings.idTablePut(concpt, arg)
     # invocation != nil means we have a non-atomic concept:
-    if invocation != nil and arg.kind == tyGenericInst and invocation.len == arg.len-1:
+    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 1 ..< invocation.len:
+      for i in FirstGenericParamAt ..< invocation.kidsLen:
         bindings.idTablePut(invocation[i], arg[i])

compiler/condsyms.nim

@@ -10,7 +10,7 @@
 # This module handles the conditional symbols.
 
 import
-  strtabs
+  std/strtabs
 
 from options import Feature
 from lineinfos import hintMin, hintMax, warnMin, warnMax
@@ -45,10 +45,8 @@ proc initDefines*(symbols: StringTableRef) =
   defineSymbol("nimNewTypedesc") # deadcode
   defineSymbol("nimrequiresnimframe") # deadcode
   defineSymbol("nimparsebiggestfloatmagic") # deadcode
-  defineSymbol("nimalias") # deadcode
   defineSymbol("nimlocks") # deadcode
-  defineSymbol("nimnode") # deadcode pending `nimnode` reference in opengl package
-    # refs https://github.com/nim-lang/opengl/pull/79
+  defineSymbol("nimnode") # deadcode
   defineSymbol("nimvarargstyped") # deadcode
   defineSymbol("nimtypedescfixed") # deadcode
   defineSymbol("nimKnowsNimvm") # deadcode
@@ -145,12 +143,26 @@ proc initDefines*(symbols: StringTableRef) =
   defineSymbol("nimHasTemplateRedefinitionPragma")
   defineSymbol("nimHasCstringCase")
   defineSymbol("nimHasCallsitePragma")
-  defineSymbol("nimHasAmbiguousEnumHint")
 
-  defineSymbol("nimHasWarnCastSizes")
+  defineSymbol("nimHasWarnCastSizes") # deadcode
   defineSymbol("nimHasOutParams")
   defineSymbol("nimHasSystemRaisesDefect")
   defineSymbol("nimHasWarnUnnamedBreak")
   defineSymbol("nimHasGenericDefine")
   defineSymbol("nimHasDefineAliases")
   defineSymbol("nimHasWarnBareExcept")
+  defineSymbol("nimHasDup")
+  defineSymbol("nimHasChecksums")
+  defineSymbol("nimHasSendable")
+  defineSymbol("nimAllowNonVarDestructor")
+  defineSymbol("nimHasQuirky")
+  defineSymbol("nimHasEnsureMove")
+  defineSymbol("nimHasNoReturnError")
+
+  defineSymbol("nimUseStrictDefs")
+  defineSymbol("nimHasNolineTooLong")
+
+  defineSymbol("nimHasCastExtendedVm")
+  defineSymbol("nimHasWarnStdPrefix")
+
+  defineSymbol("nimHasVtables")

compiler/depends.nim

@@ -14,7 +14,7 @@ import options, ast, ropes, pathutils, msgs, lineinfos
 import modulegraphs
 
 import std/[os, parseutils]
-import strutils except addf
+import std/strutils except addf
 import std/private/globs
 
 when defined(nimPreviewSlimSystem):
@@ -42,7 +42,7 @@ proc toNimblePath(s: string, isStdlib: bool): string =
     let sub = "lib/"
     var start = s.find(sub)
     if start < 0:
-      doAssert false
+      raiseAssert "unreachable"
     else:
       start += sub.len
       let base = s[start..^1]
@@ -63,12 +63,16 @@ proc toNimblePath(s: string, isStdlib: bool): string =
       sub.add "/pkgs/"
     var start = s.find(sub)
     if start < 0:
-      result = s
-    else:
-      start += sub.len
-      start += skipUntil(s, '/', start)
-      start += 1
-      result = pkgPrefix & s[start..^1]
+      sub[^1] = '2'
+      sub.add '/'
+      start = s.find(sub) # /pkgs2
+      if start < 0:
+        return s
+
+    start += sub.len
+    start += skipUntil(s, '/', start)
+    start += 1
+    result = pkgPrefix & s[start..^1]
 
 proc addDependency(c: PPassContext, g: PGen, b: Backend, n: PNode) =
   doAssert n.kind == nkSym, $n.kind
@@ -101,11 +105,6 @@ proc generateDot*(graph: ModuleGraph; project: AbsoluteFile) =
             changeFileExt(project, "dot"))
 
 proc setupDependPass*(graph: ModuleGraph; module: PSym; idgen: IdGenerator): PPassContext =
-  var g: PGen
-  new(g)
-  g.module = module
-  g.config = graph.config
-  g.graph = graph
+  result = PGen(module: module, config: graph.config, graph: graph)
   if graph.backend == nil:
     graph.backend = Backend(dotGraph: "")
-  result = g

compiler/dfa.nim

@@ -22,8 +22,9 @@
 ## "A Graph–Free Approach to Data–Flow Analysis" by Markus Mohnen.
 ## https://link.springer.com/content/pdf/10.1007/3-540-45937-5_6.pdf
 
-import ast, intsets, lineinfos, renderer, aliasanalysis
+import ast, lineinfos, renderer, aliasanalysis
 import std/private/asciitables
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -45,10 +46,10 @@ type
     case isTryBlock: bool
     of false:
       label: PSym
-      breakFixups: seq[(TPosition, seq[PNode])] #Contains the gotos for the breaks along with their pending finales
+      breakFixups: seq[(TPosition, seq[PNode])] # Contains the gotos for the breaks along with their pending finales
     of true:
       finale: PNode
-      raiseFixups: seq[TPosition] #Contains the gotos for the raises
+      raiseFixups: seq[TPosition] # Contains the gotos for the raises
 
   Con = object
     code: ControlFlowGraph
@@ -60,6 +61,7 @@ type
 proc codeListing(c: ControlFlowGraph, start = 0; last = -1): string =
   # for debugging purposes
   # first iteration: compute all necessary labels:
+  result = ""
   var jumpTargets = initIntSet()
   let last = if last < 0: c.len-1 else: min(last, c.len-1)
   for i in start..last:
@@ -111,7 +113,7 @@ proc patch(c: var Con, p: TPosition) =
 proc gen(c: var Con; n: PNode)
 
 proc popBlock(c: var Con; oldLen: int) =
-  var exits: seq[TPosition]
+  var exits: seq[TPosition] = @[]
   exits.add c.gotoI()
   for f in c.blocks[oldLen].breakFixups:
     c.patch(f[0])
@@ -128,10 +130,6 @@ template withBlock(labl: PSym; body: untyped) =
   body
   popBlock(c, oldLen)
 
-proc isTrue(n: PNode): bool =
-  n.kind == nkSym and n.sym.kind == skEnumField and n.sym.position != 0 or
-    n.kind == nkIntLit and n.intVal != 0
-
 template forkT(body) =
   let lab1 = c.forkI()
   body
@@ -183,14 +181,6 @@ proc genIf(c: var Con, n: PNode) =
     goto Lend3
   L3:
     D
-    goto Lend3 # not eliminated to simplify the join generation
-  Lend3:
-    join F3
-  Lend2:
-    join F2
-  Lend:
-    join F1
-
   ]#
   var endings: seq[TPosition] = @[]
   let oldInteresting = c.interestingInstructions
@@ -215,7 +205,6 @@ proc genAndOr(c: var Con; n: PNode) =
   #   fork lab1
   #   asgn dest, b
   # lab1:
-  #   join F1
   c.gen(n[1])
   forkT:
     c.gen(n[2])
@@ -263,8 +252,9 @@ proc genBreakOrRaiseAux(c: var Con, i: int, n: PNode) =
   if c.blocks[i].isTryBlock:
     c.blocks[i].raiseFixups.add lab1
   else:
-    var trailingFinales: seq[PNode]
-    if c.inTryStmt > 0: #Ok, we are in a try, lets see which (if any) try's we break out from:
+    var trailingFinales: seq[PNode] = @[]
+    if c.inTryStmt > 0:
+      # Ok, we are in a try, lets see which (if any) try's we break out from:
       for b in countdown(c.blocks.high, i):
         if c.blocks[b].isTryBlock:
           trailingFinales.add c.blocks[b].finale
@@ -325,7 +315,7 @@ proc genRaise(c: var Con; n: PNode) =
       if c.blocks[i].isTryBlock:
         genBreakOrRaiseAux(c, i, n)
         return
-    assert false #Unreachable
+    assert false # Unreachable
   else:
     genNoReturn(c)
 
@@ -381,16 +371,16 @@ proc genCall(c: var Con; n: PNode) =
   if t != nil: t = t.skipTypes(abstractInst)
   for i in 1..<n.len:
     gen(c, n[i])
-    if t != nil and i < t.len and isOutParam(t[i]):
+    if t != nil and i < t.signatureLen and isOutParam(t[i]):
       # Pass by 'out' is a 'must def'. Good enough for a move optimizer.
       genDef(c, n[i])
   # every call can potentially raise:
-  if false: # c.inTryStmt > 0 and canRaiseConservative(n[0]):
+  if c.inTryStmt > 0 and canRaiseConservative(n[0]):
+    inc c.interestingInstructions
     # we generate the instruction sequence:
     # fork lab1
     # goto exceptionHandler (except or finally)
     # lab1:
-    # join F1
     forkT:
       for i in countdown(c.blocks.high, 0):
         if c.blocks[i].isTryBlock:
@@ -467,7 +457,7 @@ proc gen(c: var Con; n: PNode) =
   of nkConv, nkExprColonExpr, nkExprEqExpr, nkCast, PathKinds1:
     gen(c, n[1])
   of nkVarSection, nkLetSection: genVarSection(c, n)
-  of nkDefer: doAssert false, "dfa construction pass requires the elimination of 'defer'"
+  of nkDefer: raiseAssert "dfa construction pass requires the elimination of 'defer'"
   else: discard
 
 when false:
@@ -493,7 +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):
+  when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc):
     result = c.code # will move
   else:
     shallowCopy(result, c.code)

compiler/docgen.nim

@@ -15,15 +15,16 @@
 ## For corresponding users' documentation see [Nim DocGen Tools Guide].
 
 import
-  ast, strutils, strtabs, algorithm, sequtils, options, msgs, os, idents,
+  ast, options, msgs, idents,
   wordrecg, syntaxes, renderer, lexer,
   packages/docutils/[rst, rstidx, rstgen, dochelpers],
-  json, xmltree, trees, types,
-  typesrenderer, astalgo, lineinfos, intsets,
-  pathutils, tables, nimpaths, renderverbatim, osproc, packages
+  trees, types,
+  typesrenderer, astalgo, lineinfos,
+  pathutils, nimpaths, renderverbatim, packages
 import packages/docutils/rstast except FileIndex, TLineInfo
 
-from uri import encodeUrl
+import std/[os, strutils, strtabs, algorithm, json, osproc, tables, intsets, xmltree, sequtils]
+from std/uri import encodeUrl
 from nodejs import findNodeJs
 
 when defined(nimPreviewSlimSystem):
@@ -112,13 +113,16 @@ type
 proc add(dest: var ItemPre, rst: PRstNode) = dest.add ItemFragment(isRst: true, rst: rst)
 proc add(dest: var ItemPre, str: string) = dest.add ItemFragment(isRst: false, str: str)
 
-proc addRstFileIndex(d: PDoc, info: lineinfos.TLineInfo): rstast.FileIndex =
+proc addRstFileIndex(d: PDoc, fileIndex: lineinfos.FileIndex): rstast.FileIndex =
   let invalid = rstast.FileIndex(-1)
-  result = d.nimToRstFid.getOrDefault(info.fileIndex, default = invalid)
+  result = d.nimToRstFid.getOrDefault(fileIndex, default = invalid)
   if result == invalid:
-    let fname = toFullPath(d.conf, info)
+    let fname = toFullPath(d.conf, fileIndex)
     result = addFilename(d.sharedState, fname)
-    d.nimToRstFid[info.fileIndex] = result
+    d.nimToRstFid[fileIndex] = result
+
+proc addRstFileIndex(d: PDoc, info: lineinfos.TLineInfo): rstast.FileIndex =
+  addRstFileIndex(d, info.fileIndex)
 
 proc cmpDecimalsIgnoreCase(a, b: string): int =
   ## For sorting with correct handling of cases like 'uint8' and 'uint16'.
@@ -167,6 +171,7 @@ proc cmpDecimalsIgnoreCase(a, b: string): int =
 
 proc prettyString(a: object): string =
   # xxx pending std/prettyprint refs https://github.com/nim-lang/RFCs/issues/203#issuecomment-602534906
+  result = ""
   for k, v in fieldPairs(a):
     result.add k & ": " & $v & "\n"
 
@@ -212,12 +217,16 @@ proc whichType(d: PDoc; n: PNode): PSym =
   if n.kind == nkSym:
     if d.types.strTableContains(n.sym):
       result = n.sym
+    else:
+      result = nil
   else:
+    result = nil
     for i in 0..<n.safeLen:
       let x = whichType(d, n[i])
       if x != nil: return x
 
 proc attachToType(d: PDoc; p: PSym): PSym =
+  result = nil
   let params = p.ast[paramsPos]
   template check(i) =
     result = whichType(d, params[i])
@@ -256,7 +265,16 @@ template declareClosures(currentFilename: AbsoluteFile, destFile: string) =
     of mwUnusedImportdoc: k = warnRstUnusedImportdoc
     of mwRstStyle: k = warnRstStyle
     {.gcsafe.}:
-      globalError(conf, newLineInfo(conf, AbsoluteFile filename, line, col), k, arg)
+      let errorsAsWarnings = (roPreferMarkdown in d.sharedState.options) and
+          not d.standaloneDoc  # not tolerate errors in .rst/.md files
+      if whichMsgClass(msgKind) == mcError and errorsAsWarnings:
+        liMessage(conf, newLineInfo(conf, AbsoluteFile filename, line, col),
+                  k, arg, doNothing, instLoc(), ignoreError=true)
+        # when our Markdown parser fails, we currently can only terminate the
+        # parsing (and then we will return monospaced text instead of markup):
+        raiseRecoverableError("")
+      else:
+        globalError(conf, newLineInfo(conf, AbsoluteFile filename, line, col), k, arg)
 
   proc docgenFindFile(s: string): string {.gcsafe.} =
     result = options.findFile(conf, s).string
@@ -271,7 +289,7 @@ template declareClosures(currentFilename: AbsoluteFile, destFile: string) =
     let outDirPath: RelativeFile =
         presentationPath(conf, AbsoluteFile(basedir / targetRelPath))
           # use presentationPath because `..` path can be be mangled to `_._`
-    result.targetPath = string(conf.outDir / outDirPath)
+    result = (string(conf.outDir / outDirPath), "")
     if not fileExists(result.targetPath):
       # this can happen if targetRelPath goes to parent directory `OUTDIR/..`.
       # Trying it, this may cause ambiguities, but allows us to insert
@@ -308,8 +326,9 @@ proc newDocumentor*(filename: AbsoluteFile; cache: IdentCache; conf: ConfigRef,
                     standaloneDoc = false, preferMarkdown = true,
                     hasToc = true): PDoc =
   let destFile = getOutFile2(conf, presentationPath(conf, filename), outExt, false).string
-  declareClosures(currentFilename = filename, destFile = destFile)
   new(result)
+  let d = result  # pass `d` to `declareClosures`:
+  declareClosures(currentFilename = filename, destFile = destFile)
   result.module = module
   result.conf = conf
   result.cache = cache
@@ -330,7 +349,7 @@ proc newDocumentor*(filename: AbsoluteFile; cache: IdentCache; conf: ConfigRef,
 
   if conf.configVars.hasKey("doc.googleAnalytics") and
       conf.configVars.hasKey("doc.plausibleAnalytics"):
-    doAssert false, "Either use googleAnalytics or plausibleAnalytics"
+    raiseAssert "Either use googleAnalytics or plausibleAnalytics"
 
   if conf.configVars.hasKey("doc.googleAnalytics"):
     result.analytics = """
@@ -355,7 +374,7 @@ proc newDocumentor*(filename: AbsoluteFile; cache: IdentCache; conf: ConfigRef,
   result.seenSymbols = newStringTable(modeCaseInsensitive)
   result.id = 100
   result.jEntriesFinal = newJArray()
-  initStrTable result.types
+  result.types = initStrTable()
   result.onTestSnippet =
     proc (gen: var RstGenerator; filename, cmd: string; status: int; content: string) {.gcsafe.} =
       if conf.docCmd == docCmdSkip: return
@@ -415,16 +434,21 @@ proc getVarIdx(varnames: openArray[string], id: string): int =
 proc genComment(d: PDoc, n: PNode): PRstNode =
   if n.comment.len > 0:
     d.sharedState.currFileIdx = addRstFileIndex(d, n.info)
-    result = parseRst(n.comment,
-                      toLinenumber(n.info),
-                      toColumn(n.info) + DocColOffset,
-                      d.conf, d.sharedState)
+    try:
+      result = parseRst(n.comment,
+                        toLinenumber(n.info),
+                        toColumn(n.info) + DocColOffset,
+                        d.conf, d.sharedState)
+    except ERecoverableError:
+      result = newRstNode(rnLiteralBlock, @[newRstLeaf(n.comment)])
+  else:
+    result = nil
 
 proc genRecCommentAux(d: PDoc, n: PNode): PRstNode =
   if n == nil: return nil
   result = genComment(d, n)
   if result == nil:
-    if n.kind in {nkStmtList, nkStmtListExpr, nkTypeDef, nkConstDef,
+    if n.kind in {nkStmtList, nkStmtListExpr, nkTypeDef, nkConstDef, nkTypeClassTy,
                   nkObjectTy, nkRefTy, nkPtrTy, nkAsgn, nkFastAsgn, nkSinkAsgn, nkHiddenStdConv}:
       # notin {nkEmpty..nkNilLit, nkEnumTy, nkTupleTy}:
       for i in 0..<n.len:
@@ -453,6 +477,7 @@ proc getPlainDocstring(n: PNode): string =
   elif startsWith(n.comment, "##"):
     result = n.comment
   else:
+    result = ""
     for i in 0..<n.safeLen:
       result = getPlainDocstring(n[i])
       if result.len > 0: return
@@ -468,9 +493,8 @@ proc externalDep(d: PDoc; module: PSym): string =
 proc nodeToHighlightedHtml(d: PDoc; n: PNode; result: var string;
                            renderFlags: TRenderFlags = {};
                            procLink: string) =
-  var r: TSrcGen
+  var r: TSrcGen = initTokRender(n, renderFlags)
   var literal = ""
-  initTokRender(r, n, renderFlags)
   var kind = tkEof
   var tokenPos = 0
   var procTokenPos = 0
@@ -562,10 +586,13 @@ proc runAllExamples(d: PDoc) =
     # most useful semantics is that `docCmd` comes after `rdoccmd`, so that we can (temporarily) override
     # via command line
     # D20210224T221756:here
-    let cmd = "$nim $backend -r --lib:$libpath --warning:UnusedImport:off --path:$path --nimcache:$nimcache $rdoccmd $docCmd $file" % [
+    var pathArgs = "--path:$path" % [ "path", quoteShell(d.conf.projectPath) ]
+    for p in d.conf.searchPaths:
+      pathArgs = "$args --path:$path" % [ "args", pathArgs, "path", quoteShell(p) ]
+    let cmd = "$nim $backend -r --lib:$libpath --warning:UnusedImport:off $pathArgs --nimcache:$nimcache $rdoccmd $docCmd $file" % [
       "nim", quoteShell(os.getAppFilename()),
       "backend", $d.conf.backend,
-      "path", quoteShell(d.conf.projectPath),
+      "pathArgs", pathArgs,
       "libpath", quoteShell(d.conf.libpath),
       "nimcache", quoteShell(outputDir),
       "file", quoteShell(outp),
@@ -581,7 +608,9 @@ proc runAllExamples(d: PDoc) =
       rawMessage(d.conf, hintSuccess, ["runnableExamples: " & outp.string])
       # removeFile(outp.changeFileExt(ExeExt)) # it's in nimcache, no need to remove
 
-proc quoted(a: string): string = result.addQuoted(a)
+proc quoted(a: string): string =
+  result = ""
+  result.addQuoted(a)
 
 proc toInstantiationInfo(conf: ConfigRef, info: TLineInfo): (string, int, int) =
   # xxx expose in compiler/lineinfos.nim
@@ -600,7 +629,6 @@ proc prepareExample(d: PDoc; n: PNode, topLevel: bool): tuple[rdoccmd: string, c
   let useRenderModule = false
   let loc = d.conf.toFileLineCol(n.info)
   let code = extractRunnableExamplesSource(d.conf, n)
-  let codeIndent = extractRunnableExamplesSource(d.conf, n, indent = 2)
 
   if d.conf.errorCounter > 0:
     return (rdoccmd, code)
@@ -616,6 +644,7 @@ proc prepareExample(d: PDoc; n: PNode, topLevel: bool): tuple[rdoccmd: string, c
     docComment.comment = comment
     var runnableExamples = newTree(nkStmtList,
         docComment,
+        newTree(nkImportStmt, newStrNode(nkStrLit, "std/assertions")),
         newTree(nkImportStmt, newStrNode(nkStrLit, d.filename)))
     runnableExamples.info = n.info
     for a in n.lastSon: runnableExamples.add a
@@ -629,6 +658,7 @@ proc prepareExample(d: PDoc; n: PNode, topLevel: bool): tuple[rdoccmd: string, c
   else:
     var code2 = code
     if code.len > 0 and "codeReordering" notin code:
+      let codeIndent = extractRunnableExamplesSource(d.conf, n, indent = 2)
       # hacky but simplest solution, until we devise a way to make `{.line.}`
       # work without introducing a scope
       code2 = """
@@ -639,6 +669,7 @@ $#
 #[
 $#
 ]#
+import std/assertions
 import $#
 $#
 """ % [comment, d.filename.quoted, code2]
@@ -705,7 +736,7 @@ proc getAllRunnableExamplesImpl(d: PDoc; n: PNode, dest: var ItemPre,
         let (rdoccmd, code) = prepareExample(d, n, topLevel)
         var msg = "Example:"
         if rdoccmd.len > 0: msg.add " cmd: " & rdoccmd
-        var s: string
+        var s: string = ""
         dispA(d.conf, s, "\n<p><strong class=\"examples_text\">$1</strong></p>\n",
             "\n\n\\textbf{$1}\n", [msg])
         dest.add s
@@ -921,14 +952,17 @@ proc genDeprecationMsg(d: PDoc, n: PNode): string =
     if n[1].kind in {nkStrLit..nkTripleStrLit}:
       result = getConfigVar(d.conf, "doc.deprecationmsg") % [
           "label", "Deprecated:", "message", xmltree.escape(n[1].strVal)]
+    else:
+      result = ""
   else:
-    doAssert false
+    raiseAssert "unreachable"
 
 type DocFlags = enum
   kDefault
   kForceExport
 
 proc genSeeSrc(d: PDoc, path: string, line: int): string =
+  result = ""
   let docItemSeeSrc = getConfigVar(d.conf, "doc.item.seesrc")
   if docItemSeeSrc.len > 0:
     let path = relativeTo(AbsoluteFile path, AbsoluteDir getCurrentDir(), '/')
@@ -966,11 +1000,12 @@ proc getTypeKind(n: PNode): string =
 proc toLangSymbol(k: TSymKind, n: PNode, baseName: string): LangSymbol =
   ## Converts symbol info (names/types/parameters) in `n` into format
   ## `LangSymbol` convenient for ``rst.nim``/``dochelpers.nim``.
-  result.name = baseName.nimIdentNormalize
-  result.symKind = k.toHumanStr
+  result = LangSymbol(name: baseName.nimIdentNormalize,
+      symKind: k.toHumanStr
+  )
   if k in routineKinds:
     var
-      paramTypes: seq[string]
+      paramTypes: seq[string] = @[]
     renderParamTypes(paramTypes, n[paramsPos], toNormalize=true)
     let paramNames = renderParamNames(n[paramsPos], toNormalize=true)
     # In some rare cases (system.typeof) parameter type is not set for default:
@@ -995,9 +1030,8 @@ proc toLangSymbol(k: TSymKind, n: PNode, baseName: string): LangSymbol =
         genNode = n[miscPos][1]   # FIXME: what is index 1?
     if genNode != nil:
       var literal = ""
-      var r: TSrcGen
-      initTokRender(r, genNode, {renderNoBody, renderNoComments,
-        renderNoPragmas, renderNoProcDefs, renderExpandUsing})
+      var r: TSrcGen = initTokRender(genNode, {renderNoBody, renderNoComments,
+        renderNoPragmas, renderNoProcDefs, renderExpandUsing, renderNoPostfix})
       var kind = tkEof
       while true:
         getNextTok(r, kind, literal)
@@ -1017,16 +1051,15 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
   var result = ""
   var literal, plainName = ""
   var kind = tkEof
-  var comm: ItemPre
+  var comm: ItemPre = default(ItemPre)
   if n.kind in routineDefs:
     getAllRunnableExamples(d, n, comm)
   else:
     comm.add genRecComment(d, n)
 
-  var r: TSrcGen
   # Obtain the plain rendered string for hyperlink titles.
-  initTokRender(r, n, {renderNoBody, renderNoComments, renderDocComments,
-    renderNoPragmas, renderNoProcDefs, renderExpandUsing})
+  var r: TSrcGen = initTokRender(n, {renderNoBody, renderNoComments, renderDocComments,
+    renderNoPragmas, renderNoProcDefs, renderExpandUsing, renderNoPostfix})
   while true:
     getNextTok(r, kind, literal)
     if kind == tkEof:
@@ -1053,6 +1086,9 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
     symbolOrIdEnc = encodeUrl(symbolOrId, usePlus = false)
     deprecationMsg = genDeprecationMsg(d, pragmaNode)
     rstLangSymbol = toLangSymbol(k, n, cleanPlainSymbol)
+    symNameNode =
+      if nameNode.kind == nkPostfix: nameNode[1]
+      else: nameNode
 
   # we generate anchors automatically for subsequent use in doc comments
   let lineinfo = rstast.TLineInfo(
@@ -1060,12 +1096,13 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
       fileIndex: addRstFileIndex(d, nameNode.info))
   addAnchorNim(d.sharedState, external = false, refn = symbolOrId,
                tooltip = detailedName, langSym = rstLangSymbol,
-               priority = symbolPriority(k), info = lineinfo)
+               priority = symbolPriority(k), info = lineinfo,
+               module = addRstFileIndex(d, FileIndex d.module.position))
 
-  let renderFlags =
-    if nonExports: {renderNoBody, renderNoComments, renderDocComments, renderSyms,
-      renderExpandUsing, renderNonExportedFields}
-    else: {renderNoBody, renderNoComments, renderDocComments, renderSyms, renderExpandUsing}
+  var renderFlags = {renderNoBody, renderNoComments, renderDocComments,
+    renderSyms, renderExpandUsing, renderNoPostfix}
+  if nonExports:
+    renderFlags.incl renderNonExportedFields
   nodeToHighlightedHtml(d, n, result, renderFlags, symbolOrIdEnc)
 
   let seeSrc = genSeeSrc(d, toFullPath(d.conf, n.info), n.info.line.int)
@@ -1088,18 +1125,19 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
   let external = d.destFile.AbsoluteFile.relativeTo(d.conf.outDir, '/').changeFileExt(HtmlExt).string
 
   var attype = ""
-  if k in routineKinds and nameNode.kind == nkSym:
+  if k in routineKinds and symNameNode.kind == nkSym:
     let att = attachToType(d, nameNode.sym)
     if att != nil:
       attype = esc(d.target, att.name.s)
-  elif k == skType and nameNode.kind == nkSym and nameNode.sym.typ.kind in {tyEnum, tyBool}:
-    let etyp = nameNode.sym.typ
+  elif k == skType and symNameNode.kind == nkSym and
+      symNameNode.sym.typ.kind in {tyEnum, tyBool}:
+    let etyp = symNameNode.sym.typ
     for e in etyp.n:
       if e.sym.kind != skEnumField: continue
       let plain = renderPlainSymbolName(e)
       let symbolOrId = d.newUniquePlainSymbol(plain)
       setIndexTerm(d[], ieNim, htmlFile = external, id = symbolOrId,
-                   term = plain, linkTitle = nameNode.sym.name.s & '.' & plain,
+                   term = plain, linkTitle = symNameNode.sym.name.s & '.' & plain,
                    linkDesc = xmltree.escape(getPlainDocstring(e).docstringSummary),
                    line = n.info.line.int)
 
@@ -1120,18 +1158,23 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
                linkTitle = detailedName,
                linkDesc = xmltree.escape(plainDocstring.docstringSummary),
                line = n.info.line.int)
-  if k == skType and nameNode.kind == nkSym:
-    d.types.strTableAdd nameNode.sym
+  if k == skType and symNameNode.kind == nkSym:
+    d.types.strTableAdd symNameNode.sym
 
-proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind): JsonItem =
+proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false): JsonItem =
   if not isVisible(d, nameNode): return
   var
     name = getNameEsc(d, nameNode)
     comm = genRecComment(d, n)
     r: TSrcGen
-  initTokRender(r, n, {renderNoBody, renderNoComments, renderDocComments, renderExpandUsing})
-  result.json = %{ "name": %name, "type": %($k), "line": %n.info.line.int,
+    renderFlags = {renderNoBody, renderNoComments, renderDocComments,
+      renderExpandUsing, renderNoPostfix}
+  if nonExports:
+    renderFlags.incl renderNonExportedFields
+  r = initTokRender(n, renderFlags)
+  result = JsonItem(json: %{ "name": %name, "type": %($k), "line": %n.info.line.int,
                    "col": %n.info.col}
+  )
   if comm != nil:
     result.rst = comm
     result.rstField = "description"
@@ -1161,10 +1204,9 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind): JsonItem =
       result.json["signature"]["genericParams"] = newJArray()
       for genericParam in n[genericParamsPos]:
         var param = %{"name": %($genericParam)}
-        if genericParam.sym.typ.sons.len > 0:
+        if genericParam.sym.typ.len > 0:
           param["types"] = newJArray()
-        for kind in genericParam.sym.typ.sons:
-          param["types"].add %($kind)
+        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)
@@ -1258,6 +1300,8 @@ proc documentNewEffect(cache: IdentCache; n: PNode): PNode =
   let s = n[namePos].sym
   if tfReturnsNew in s.typ.flags:
     result = newIdentNode(getIdent(cache, "new"), n.info)
+  else:
+    result = nil
 
 proc documentEffect(cache: IdentCache; n, x: PNode, effectType: TSpecialWord, idx: int): PNode =
   let spec = effectSpec(x, effectType)
@@ -1280,6 +1324,8 @@ proc documentEffect(cache: IdentCache; n, x: PNode, effectType: TSpecialWord, id
 
     result = newTreeI(nkExprColonExpr, n.info,
       newIdentNode(getIdent(cache, $effectType), n.info), effects)
+  else:
+    result = nil
 
 proc documentWriteEffect(cache: IdentCache; n: PNode; flag: TSymFlag; pragmaName: string): PNode =
   let s = n[namePos].sym
@@ -1293,6 +1339,8 @@ proc documentWriteEffect(cache: IdentCache; n: PNode; flag: TSymFlag; pragmaName
   if effects.len > 0:
     result = newTreeI(nkExprColonExpr, n.info,
       newIdentNode(getIdent(cache, pragmaName), n.info), effects)
+  else:
+    result = nil
 
 proc documentRaises*(cache: IdentCache; n: PNode) =
   if n[namePos].kind != nkSym: return
@@ -1358,7 +1406,8 @@ 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:
+      # 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:
@@ -1366,7 +1415,7 @@ proc generateDoc*(d: PDoc, n, orig: PNode, config: ConfigRef, docFlags: DocFlags
   of nkExportExceptStmt: discard "transformed into nkExportStmt by semExportExcept"
   of nkFromStmt, nkImportExceptStmt: traceDeps(d, n[0])
   of nkCallKinds:
-    var comm: ItemPre
+    var comm: ItemPre = default(ItemPre)
     getAllRunnableExamples(d, n, comm)
     if comm.len != 0: d.modDescPre.add(comm)
   else: discard
@@ -1451,7 +1500,8 @@ proc finishGenerateDoc*(d: var PDoc) =
                                   isGroup: true),
                        priority = symbolPriority(k),
                        # select index `0` just to have any meaningful warning:
-                       info = overloadChoices[0].info)
+                       info = overloadChoices[0].info,
+                       module = addRstFileIndex(d, FileIndex d.module.position))
 
   if optGenIndexOnly in d.conf.globalOptions:
     return
@@ -1474,7 +1524,7 @@ proc finishGenerateDoc*(d: var PDoc) =
       overloadChoices.sort(cmp)
       var nameContent = ""
       for item in overloadChoices:
-        var itemDesc: string
+        var itemDesc: string = ""
         renderItemPre(d, item.descRst, itemDesc)
         nameContent.add(
           getConfigVar(d.conf, "doc.item") % (
@@ -1500,7 +1550,7 @@ proc finishGenerateDoc*(d: var PDoc) =
   for i, entry in d.jEntriesPre:
     if entry.rst != nil:
       let resolved = resolveSubs(d.sharedState, entry.rst)
-      var str: string
+      var str: string = ""
       renderRstToOut(d[], resolved, str)
       entry.json[entry.rstField] = %str
       d.jEntriesPre[i].rst = nil
@@ -1513,7 +1563,7 @@ proc finishGenerateDoc*(d: var PDoc) =
 proc add(d: PDoc; j: JsonItem) =
   if j.json != nil or j.rst != nil: d.jEntriesPre.add j
 
-proc generateJson*(d: PDoc, n: PNode, includeComments: bool = true) =
+proc generateJson*(d: PDoc, n: PNode, config: ConfigRef, includeComments: bool = true) =
   case n.kind
   of nkPragma:
     let doctypeNode = findPragma(n, wDoctype)
@@ -1545,14 +1595,14 @@ proc generateJson*(d: PDoc, n: PNode, includeComments: bool = true) =
       if n[i].kind != nkCommentStmt:
         # order is always 'type var let const':
         d.add genJsonItem(d, n[i], n[i][0],
-                succ(skType, ord(n.kind)-ord(nkTypeSection)))
+                succ(skType, ord(n.kind)-ord(nkTypeSection)), optShowNonExportedFields in config.globalOptions)
   of nkStmtList:
     for i in 0..<n.len:
-      generateJson(d, n[i], includeComments)
+      generateJson(d, n[i], config, includeComments)
   of nkWhenStmt:
     # generate documentation for the first branch only:
     if not checkForFalse(n[0][0]):
-      generateJson(d, lastSon(n[0]), includeComments)
+      generateJson(d, lastSon(n[0]), config, includeComments)
   else: discard
 
 proc genTagsItem(d: PDoc, n, nameNode: PNode, k: TSymKind): string =
@@ -1615,7 +1665,7 @@ proc genSection(d: PDoc, kind: TSymKind, groupedToc = false) =
     for plainName in overloadableNames.sorted(cmpDecimalsIgnoreCase):
       var overloadChoices = d.tocTable[kind][plainName]
       overloadChoices.sort(cmp)
-      var content: string
+      var content: string = ""
       for item in overloadChoices:
         content.add item.content
       d.toc2[kind].add getConfigVar(d.conf, "doc.section.toc2") % [
@@ -1646,7 +1696,7 @@ proc relLink(outDir: AbsoluteDir, destFile: AbsoluteFile, linkto: RelativeFile):
 
 proc genOutFile(d: PDoc, groupedToc = false): string =
   var
-    code, content: string
+    code, content: string = ""
     title = ""
   var j = 0
   var toc = ""
@@ -1697,7 +1747,7 @@ proc genOutFile(d: PDoc, groupedToc = false): string =
         "moduledesc", d.modDescFinal, "date", getDateStr(), "time", getClockStr(),
         "content", content, "author", d.meta[metaAuthor],
         "version", esc(d.target, d.meta[metaVersion]), "analytics", d.analytics,
-        "deprecationMsg", d.modDeprecationMsg]
+        "deprecationMsg", d.modDeprecationMsg, "nimVersion", $NimMajor & "." & $NimMinor & "." & $NimPatch]
   else:
     code = content
   result = code
@@ -1755,7 +1805,7 @@ proc writeOutput*(d: PDoc, useWarning = false, groupedToc = false) =
 
 proc writeOutputJson*(d: PDoc, useWarning = false) =
   runAllExamples(d)
-  var modDesc: string
+  var modDesc: string = ""
   for desc in d.modDescFinal:
     modDesc &= desc
   let content = %*{"orig": d.filename,
@@ -1763,11 +1813,11 @@ proc writeOutputJson*(d: PDoc, useWarning = false) =
     "moduleDescription": modDesc,
     "entries": d.jEntriesFinal}
   if optStdout in d.conf.globalOptions:
-    write(stdout, $content)
+    writeLine(stdout, $content)
   else:
     let dir = d.destFile.splitFile.dir
     createDir(dir)
-    var f: File
+    var f: File = default(File)
     if open(f, d.destFile, fmWrite):
       write(f, $content)
       close(f)
@@ -1801,13 +1851,16 @@ proc commandRstAux(cache: IdentCache, conf: ConfigRef;
   var filen = addFileExt(filename, "txt")
   var d = newDocumentor(filen, cache, conf, outExt, standaloneDoc = true,
                         preferMarkdown = preferMarkdown, hasToc = false)
-  let rst = parseRst(readFile(filen.string),
-                     line=LineRstInit, column=ColRstInit,
-                     conf, d.sharedState)
-  d.modDescPre = @[ItemFragment(isRst: true, rst: rst)]
-  finishGenerateDoc(d)
-  writeOutput(d)
-  generateIndex(d)
+  try:
+    let rst = parseRst(readFile(filen.string),
+                      line=LineRstInit, column=ColRstInit,
+                      conf, d.sharedState)
+    d.modDescPre = @[ItemFragment(isRst: true, rst: rst)]
+    finishGenerateDoc(d)
+    writeOutput(d)
+    generateIndex(d)
+  except ERecoverableError:
+    discard "already reported the error"
 
 proc commandRst2Html*(cache: IdentCache, conf: ConfigRef,
                       preferMarkdown=false) =
@@ -1826,7 +1879,7 @@ proc commandJson*(cache: IdentCache, conf: ConfigRef) =
                           status: int; content: string) {.gcsafe.} =
     localError(conf, newLineInfo(conf, AbsoluteFile d.filename, -1, -1),
                warnUser, "the ':test:' attribute is not supported by this backend")
-  generateJson(d, ast)
+  generateJson(d, ast, conf)
   finishGenerateDoc(d)
   let json = d.jEntriesFinal
   let content = pretty(json)
@@ -1878,7 +1931,7 @@ proc commandBuildIndex*(conf: ConfigRef, dir: string, outFile = RelativeFile"")
       "title", "Index",
       "subtitle", "", "tableofcontents", "", "moduledesc", "",
       "date", getDateStr(), "time", getClockStr(),
-      "content", content, "author", "", "version", "", "analytics", ""]
+      "content", content, "author", "", "version", "", "analytics", "", "nimVersion", $NimMajor & "." & $NimMinor & "." & $NimPatch]
   # no analytics because context is not available
 
   try:

compiler/docgen2.nim

@@ -39,10 +39,12 @@ template closeImpl(body: untyped) {.dirty.} =
       discard
 
 proc closeDoc*(graph: ModuleGraph; p: PPassContext, n: PNode): PNode =
+  result = nil
   closeImpl:
     writeOutput(g.doc, useWarning, groupedToc)
 
 proc closeJson*(graph: ModuleGraph; p: PPassContext, n: PNode): PNode =
+  result = nil
   closeImpl:
     writeOutputJson(g.doc, useWarning)
 
@@ -56,7 +58,7 @@ proc processNodeJson*(c: PPassContext, n: PNode): PNode =
   result = n
   var g = PGen(c)
   if shouldProcess(g):
-    generateJson(g.doc, n, false)
+    generateJson(g.doc, n, g.config, false)
 
 template myOpenImpl(ext: untyped) {.dirty.} =
   var g: PGen

compiler/enumtostr.nim

@@ -6,15 +6,15 @@ when defined(nimPreviewSlimSystem):
 
 
 proc genEnumToStrProc*(t: PType; info: TLineInfo; g: ModuleGraph; idgen: IdGenerator): PSym =
-  result = newSym(skProc, getIdent(g.cache, "$"), nextSymId idgen, t.owner, info)
+  result = newSym(skProc, getIdent(g.cache, "$"), idgen, t.owner, info)
 
-  let dest = newSym(skParam, getIdent(g.cache, "e"), nextSymId idgen, result, info)
+  let dest = newSym(skParam, getIdent(g.cache, "e"), idgen, result, info)
   dest.typ = t
 
-  let res = newSym(skResult, getIdent(g.cache, "result"), nextSymId idgen, result, info)
+  let res = newSym(skResult, getIdent(g.cache, "result"), idgen, result, info)
   res.typ = getSysType(g, info, tyString)
 
-  result.typ = newType(tyProc, nextTypeId idgen, t.owner)
+  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)
@@ -56,26 +56,27 @@ proc searchObjCaseImpl(obj: PNode; field: PSym): PNode =
     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.len > 0:
-    result = searchObjCase(t[0].skipTypes({tyAlias, tyGenericInst, tyRef, tyPtr}), 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"), nextSymId idgen, t.owner, info)
+  result = newSym(skProc, getIdent(g.cache, "objDiscMapping"), idgen, t.owner, info)
 
-  let dest = newSym(skParam, getIdent(g.cache, "e"), nextSymId idgen, result, info)
+  let dest = newSym(skParam, getIdent(g.cache, "e"), idgen, result, info)
   dest.typ = field.typ
 
-  let res = newSym(skResult, getIdent(g.cache, "result"), nextSymId idgen, result, info)
+  let res = newSym(skResult, getIdent(g.cache, "result"), idgen, result, info)
   res.typ = getSysType(g, info, tyUInt8)
 
-  result.typ = newType(tyProc, nextTypeId idgen, t.owner)
+  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)

compiler/errorhandling.nim

@@ -10,7 +10,8 @@
 ## This module contains support code for new-styled error
 ## handling via an `nkError` node kind.
 
-import ast, renderer, options, strutils, types
+import ast, renderer, options, types
+import std/strutils
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -40,7 +41,8 @@ proc newError*(wrongNode: PNode; k: ErrorKind; args: varargs[PNode]): PNode =
   let innerError = errorSubNode(wrongNode)
   if innerError != nil:
     return innerError
-  result = newNodeIT(nkError, wrongNode.info, newType(tyError, ItemId(module: -1, item: -1), nil))
+  var idgen = idGeneratorForPackage(-1'i32)
+  result = newNodeIT(nkError, wrongNode.info, newType(tyError, idgen, nil))
   result.add wrongNode
   result.add newIntNode(nkIntLit, ord(k))
   for a in args: result.add a
@@ -50,7 +52,8 @@ proc newError*(wrongNode: PNode; msg: string): PNode =
   let innerError = errorSubNode(wrongNode)
   if innerError != nil:
     return innerError
-  result = newNodeIT(nkError, wrongNode.info, newType(tyError, ItemId(module: -1, item: -1), nil))
+  var idgen = idGeneratorForPackage(-1'i32)
+  result = newNodeIT(nkError, wrongNode.info, newType(tyError, idgen, nil))
   result.add wrongNode
   result.add newIntNode(nkIntLit, ord(CustomError))
   result.add newStrNode(msg, wrongNode.info)

compiler/evalffi.nim

@@ -9,9 +9,11 @@
 
 ## This file implements the FFI part of the evaluator for Nim code.
 
-import ast, types, options, tables, dynlib, msgs, lineinfos
-from os import getAppFilename
-import pkg/libffi
+import ast, types, options, msgs, lineinfos
+from std/os import getAppFilename
+import libffi/libffi
+
+import std/[tables, dynlib]
 
 when defined(windows):
   const libcDll = "msvcrt.dll"
@@ -37,9 +39,10 @@ else:
   var gExeHandle = loadLib()
 
 proc getDll(conf: ConfigRef, cache: var TDllCache; dll: string; info: TLineInfo): pointer =
+  result = nil
   if dll in cache:
     return cache[dll]
-  var libs: seq[string]
+  var libs: seq[string] = @[]
   libCandidates(dll, libs)
   for c in libs:
     result = loadLib(c)
@@ -61,7 +64,7 @@ proc importcSymbol*(conf: ConfigRef, sym: PSym): PNode =
     let lib = sym.annex
     if lib != nil and lib.path.kind notin {nkStrLit..nkTripleStrLit}:
       globalError(conf, sym.info, "dynlib needs to be a string lit")
-    var theAddr: pointer
+    var theAddr: pointer = nil
     if (lib.isNil or lib.kind == libHeader) and not gExeHandle.isNil:
       libPathMsg = "current exe: " & getAppFilename() & " nor libc: " & libcDll
       # first try this exe itself:
@@ -96,7 +99,7 @@ proc mapType(conf: ConfigRef, t: ast.PType): ptr libffi.Type =
      tyTyped, tyTypeDesc, tyProc, tyArray, tyStatic, tyNil:
     result = addr libffi.type_pointer
   of tyDistinct, tyAlias, tySink:
-    result = mapType(conf, t[0])
+    result = mapType(conf, t.skipModifier)
   else:
     result = nil
   # too risky:
@@ -108,6 +111,7 @@ proc mapCallConv(conf: ConfigRef, cc: TCallingConvention, info: TLineInfo): TABI
   of ccStdCall: result = when defined(windows) and defined(x86): STDCALL else: DEFAULT_ABI
   of ccCDecl: result = DEFAULT_ABI
   else:
+    result = default(TABI)
     globalError(conf, info, "cannot map calling convention to FFI")
 
 template rd(typ, p: untyped): untyped = (cast[ptr typ](p))[]
@@ -122,16 +126,18 @@ proc packSize(conf: ConfigRef, v: PNode, typ: PType): int =
     if v.kind in {nkNilLit, nkPtrLit}:
       result = sizeof(pointer)
     else:
-      result = sizeof(pointer) + packSize(conf, v[0], typ.lastSon)
+      result = sizeof(pointer) + packSize(conf, v[0], typ.elementType)
   of tyDistinct, tyGenericInst, tyAlias, tySink:
-    result = packSize(conf, v, typ[0])
+    result = packSize(conf, v, typ.skipModifier)
   of tyArray:
     # consider: ptr array[0..1000_000, int] which is common for interfacing;
     # we use the real length here instead
     if v.kind in {nkNilLit, nkPtrLit}:
       result = sizeof(pointer)
     elif v.len != 0:
-      result = v.len * packSize(conf, v[0], typ[1])
+      result = v.len * packSize(conf, v[0], typ.elementType)
+    else:
+      result = 0
   else:
     result = getSize(conf, typ).int
 
@@ -140,6 +146,7 @@ proc pack(conf: ConfigRef, v: PNode, typ: PType, res: pointer)
 proc getField(conf: ConfigRef, n: PNode; position: int): PSym =
   case n.kind
   of nkRecList:
+    result = nil
     for i in 0..<n.len:
       result = getField(conf, n[i], position)
       if result != nil: return
@@ -154,7 +161,8 @@ proc getField(conf: ConfigRef, n: PNode; position: int): PSym =
       else: internalError(conf, n.info, "getField(record case branch)")
   of nkSym:
     if n.sym.position == position: result = n.sym
-  else: discard
+    else: result = nil
+  else: result = nil
 
 proc packObject(conf: ConfigRef, x: PNode, typ: PType, res: pointer) =
   internalAssert conf, x.kind in {nkObjConstr, nkPar, nkTupleConstr}
@@ -226,19 +234,19 @@ proc pack(conf: ConfigRef, v: PNode, typ: PType, res: pointer) =
         packRecCheck = 0
         globalError(conf, v.info, "cannot map value to FFI " & typeToString(v.typ))
       inc packRecCheck
-      pack(conf, v[0], typ.lastSon, res +! sizeof(pointer))
+      pack(conf, v[0], typ.elementType, res +! sizeof(pointer))
       dec packRecCheck
       awr(pointer, res +! sizeof(pointer))
   of tyArray:
-    let baseSize = getSize(conf, typ[1])
+    let baseSize = getSize(conf, typ.elementType)
     for i in 0..<v.len:
-      pack(conf, v[i], typ[1], res +! i * baseSize)
+      pack(conf, v[i], typ.elementType, res +! i * baseSize)
   of tyObject, tyTuple:
     packObject(conf, v, typ, res)
   of tyNil:
     discard
   of tyDistinct, tyGenericInst, tyAlias, tySink:
-    pack(conf, v, typ[0], res)
+    pack(conf, v, typ.skipModifier, res)
   else:
     globalError(conf, v.info, "cannot map value to FFI " & typeToString(v.typ))
 
@@ -296,9 +304,9 @@ proc unpackArray(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
     result = n
     if result.kind != nkBracket:
       globalError(conf, n.info, "cannot map value from FFI")
-  let baseSize = getSize(conf, typ[1])
+  let baseSize = getSize(conf, typ.elementType)
   for i in 0..<result.len:
-    result[i] = unpack(conf, x +! i * baseSize, typ[1], result[i])
+    result[i] = unpack(conf, x +! i * baseSize, typ.elementType, result[i])
 
 proc canonNodeKind(k: TNodeKind): TNodeKind =
   case k
@@ -356,6 +364,7 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
     of 4: awi(nkIntLit, rd(int32, x).BiggestInt)
     of 8: awi(nkIntLit, rd(int64, x).BiggestInt)
     else:
+      result = nil
       globalError(conf, n.info, "cannot map value from FFI (tyEnum, tySet)")
   of tyFloat: awf(nkFloatLit, rd(float, x))
   of tyFloat32: awf(nkFloat32Lit, rd(float32, x))
@@ -378,9 +387,10 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
       awi(nkPtrLit, cast[int](p))
     elif n != nil and n.len == 1:
       internalAssert(conf, n.kind == nkRefTy)
-      n[0] = unpack(conf, p, typ.lastSon, n[0])
+      n[0] = unpack(conf, p, typ.elementType, n[0])
       result = n
     else:
+      result = nil
       globalError(conf, n.info, "cannot map value from FFI " & typeToString(typ))
   of tyObject, tyTuple:
     result = unpackObject(conf, x, typ, n)
@@ -395,9 +405,10 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
   of tyNil:
     setNil()
   of tyDistinct, tyGenericInst, tyAlias, tySink:
-    result = unpack(conf, x, typ.lastSon, n)
+    result = unpack(conf, x, typ.skipModifier, n)
   else:
     # XXX what to do with 'array' here?
+    result = nil
     globalError(conf, n.info, "cannot map value from FFI " & typeToString(typ))
 
 proc fficast*(conf: ConfigRef, x: PNode, destTyp: PType): PNode =
@@ -423,8 +434,8 @@ proc fficast*(conf: ConfigRef, x: PNode, destTyp: PType): PNode =
 proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =
   internalAssert conf, call[0].kind == nkPtrLit
 
-  var cif: TCif
-  var sig: ParamList
+  var cif: TCif = default(TCif)
+  var sig: ParamList = default(ParamList)
   # use the arguments' types for varargs support:
   for i in 1..<call.len:
     sig[i-1] = mapType(conf, call[i].typ)
@@ -433,24 +444,24 @@ proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =
 
   let typ = call[0].typ
   if prep_cif(cif, mapCallConv(conf, typ.callConv, call.info), cuint(call.len-1),
-              mapType(conf, typ[0]), sig) != OK:
+              mapType(conf, typ.returnType), sig) != OK:
     globalError(conf, call.info, "error in FFI call")
 
-  var args: ArgList
+  var args: ArgList = default(ArgList)
   let fn = cast[pointer](call[0].intVal)
   for i in 1..<call.len:
     var t = call[i].typ
     args[i-1] = alloc0(packSize(conf, call[i], t))
     pack(conf, call[i], t, args[i-1])
-  let retVal = if isEmptyType(typ[0]): pointer(nil)
-               else: alloc(getSize(conf, typ[0]).int)
+  let retVal = if isEmptyType(typ.returnType): pointer(nil)
+               else: alloc(getSize(conf, typ.returnType).int)
 
   libffi.call(cif, fn, retVal, args)
 
   if retVal.isNil:
     result = newNode(nkEmpty)
   else:
-    result = unpack(conf, retVal, typ[0], nil)
+    result = unpack(conf, retVal, typ.returnType, nil)
     result.info = call.info
 
   if retVal != nil: dealloc retVal
@@ -463,8 +474,8 @@ proc callForeignFunction*(conf: ConfigRef, fn: PNode, fntyp: PType,
                           info: TLineInfo): PNode =
   internalAssert conf, fn.kind == nkPtrLit
 
-  var cif: TCif
-  var sig: ParamList
+  var cif: TCif = default(TCif)
+  var sig: ParamList = default(ParamList)
   for i in 0..len-1:
     var aTyp = args[i+start].typ
     if aTyp.isNil:
@@ -478,7 +489,7 @@ proc callForeignFunction*(conf: ConfigRef, fn: PNode, fntyp: PType,
               mapType(conf, fntyp[0]), sig) != OK:
     globalError(conf, info, "error in FFI call")
 
-  var cargs: ArgList
+  var cargs: ArgList = default(ArgList)
   let fn = cast[pointer](fn.intVal)
   for i in 0..len-1:
     let t = args[i+start].typ

compiler/evaltempl.nim

@@ -9,16 +9,16 @@
 
 ## Template evaluation engine. Now hygienic.
 
-import
-  strutils, options, ast, astalgo, msgs, renderer, lineinfos, idents
+import options, ast, astalgo, msgs, renderer, lineinfos, idents, trees
+import std/strutils
 
 type
   TemplCtx = object
     owner, genSymOwner: PSym
     instLines: bool   # use the instantiation lines numbers
     isDeclarative: bool
-    mapping: TIdTable # every gensym'ed symbol needs to be mapped to some
-                      # new symbol
+    mapping: SymMapping # every gensym'ed symbol needs to be mapped to some
+                        # new symbol
     config: ConfigRef
     ic: IdentCache
     instID: int
@@ -44,12 +44,12 @@ proc evalTemplateAux(templ, actual: PNode, c: var TemplCtx, result: PNode) =
         handleParam actual[s.position]
       elif (s.owner != nil) and (s.kind == skGenericParam or
            s.kind == skType and s.typ != nil and s.typ.kind == tyGenericParam):
-        handleParam actual[s.owner.typ.len + s.position - 1]
+        handleParam actual[s.owner.typ.signatureLen + s.position - 1]
       else:
         internalAssert c.config, sfGenSym in s.flags or s.kind == skType
-        var x = PSym(idTableGet(c.mapping, s))
+        var x = idTableGet(c.mapping, s)
         if x == nil:
-          x = copySym(s, nextSymId(c.idgen))
+          x = copySym(s, c.idgen)
           # sem'check needs to set the owner properly later, see bug #9476
           x.owner = nil # c.genSymOwner
           #if x.kind == skParam and x.owner.kind == skModule:
@@ -116,7 +116,7 @@ proc evalTemplateArgs(n: PNode, s: PSym; conf: ConfigRef; fromHlo: bool): PNode
     # now that we have working untyped parameters.
     genericParams = if fromHlo: 0
                     else: s.ast[genericParamsPos].len
-    expectedRegularParams = s.typ.len-1
+    expectedRegularParams = s.typ.paramsLen
     givenRegularParams = totalParams - genericParams
   if givenRegularParams < 0: givenRegularParams = 0
 
@@ -182,14 +182,14 @@ proc evalTemplate*(n: PNode, tmpl, genSymOwner: PSym;
 
   # replace each param by the corresponding node:
   var args = evalTemplateArgs(n, tmpl, conf, fromHlo)
-  var ctx: TemplCtx
-  ctx.owner = tmpl
-  ctx.genSymOwner = genSymOwner
-  ctx.config = conf
-  ctx.ic = ic
-  initIdTable(ctx.mapping)
-  ctx.instID = instID[]
-  ctx.idgen = idgen
+  var ctx = TemplCtx(owner: tmpl,
+    genSymOwner: genSymOwner,
+    config: conf,
+    ic: ic,
+    mapping: initSymMapping(),
+    instID: instID[],
+    idgen: idgen
+  )
 
   let body = tmpl.ast[bodyPos]
   #echo "instantion of ", renderTree(body, {renderIds})

compiler/expanddefaults.nim

@@ -0,0 +1,131 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+import lineinfos, ast, types
+
+proc caseObjDefaultBranch*(obj: PNode; branch: Int128): int =
+  result = 0
+  for i in 1 ..< obj.len:
+    for j in 0 .. obj[i].len - 2:
+      if obj[i][j].kind == nkRange:
+        let x = getOrdValue(obj[i][j][0])
+        let y = getOrdValue(obj[i][j][1])
+        if branch >= x and branch <= y:
+          return i
+      elif getOrdValue(obj[i][j]) == branch:
+        return i
+    if obj[i].len == 1:
+      # else branch
+      return i
+  return 1
+
+template newZero(t: PType; info: TLineInfo; k = nkIntLit): PNode = newNodeIT(k, info, t)
+
+proc expandDefault*(t: PType; info: TLineInfo): PNode
+
+proc expandField(s: PSym; info: TLineInfo): PNode =
+  result = newNodeIT(nkExprColonExpr, info, s.typ)
+  result.add newSymNode(s)
+  result.add expandDefault(s.typ, info)
+
+proc expandDefaultN(n: PNode; info: TLineInfo; res: PNode) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      expandDefaultN(n[i], info, res)
+  of nkRecCase:
+    res.add expandField(n[0].sym, info)
+    var branch = Zero
+    let constOrNil = n[0].sym.astdef
+    if constOrNil != nil:
+      branch = getOrdValue(constOrNil)
+
+    let selectedBranch = caseObjDefaultBranch(n, branch)
+    let b = lastSon(n[selectedBranch])
+    expandDefaultN b, info, res
+  of nkSym:
+    res.add expandField(n.sym, info)
+  else:
+    discard
+
+proc expandDefaultObj(t: PType; info: TLineInfo; res: PNode) =
+  if t.baseClass != nil:
+    expandDefaultObj(t.baseClass, info, res)
+  expandDefaultN(t.n, info, res)
+
+proc expandDefault(t: PType; info: TLineInfo): PNode =
+  case t.kind
+  of tyInt:     result = newZero(t, info, nkIntLit)
+  of tyInt8:    result = newZero(t, info, nkInt8Lit)
+  of tyInt16:   result = newZero(t, info, nkInt16Lit)
+  of tyInt32:   result = newZero(t, info, nkInt32Lit)
+  of tyInt64:   result = newZero(t, info, nkInt64Lit)
+  of tyUInt:    result = newZero(t, info, nkUIntLit)
+  of tyUInt8:   result = newZero(t, info, nkUInt8Lit)
+  of tyUInt16:  result = newZero(t, info, nkUInt16Lit)
+  of tyUInt32:  result = newZero(t, info, nkUInt32Lit)
+  of tyUInt64:  result = newZero(t, info, nkUInt64Lit)
+  of tyFloat:   result = newZero(t, info, nkFloatLit)
+  of tyFloat32: result = newZero(t, info, nkFloat32Lit)
+  of tyFloat64: result = newZero(t, info, nkFloat64Lit)
+  of tyFloat128: result = newZero(t, info, nkFloat64Lit)
+  of tyChar:    result = newZero(t, info, nkCharLit)
+  of tyBool:    result = newZero(t, info, nkIntLit)
+  of tyEnum:
+    # Could use low(T) here to finally fix old language quirks
+    result = newZero(t, info, nkIntLit)
+  of tyRange:
+    # Could use low(T) here to finally fix old language quirks
+    result = expandDefault(skipModifier t, info)
+  of tyVoid: result = newZero(t, info, nkEmpty)
+  of tySink, tyGenericInst, tyDistinct, tyAlias, tyOwned:
+    result = expandDefault(t.skipModifier, info)
+  of tyOrdinal, tyGenericBody, tyGenericParam, tyInferred, tyStatic:
+    if t.hasElementType:
+      result = expandDefault(t.skipModifier, info)
+    else:
+      result = newZero(t, info, nkEmpty)
+  of tyFromExpr:
+    if t.n != nil and t.n.typ != nil:
+      result = expandDefault(t.n.typ, info)
+    else:
+      result = newZero(t, info, nkEmpty)
+  of tyArray:
+    result = newZero(t, info, nkBracket)
+    let n = toInt64(lengthOrd(nil, t))
+    for i in 0..<n:
+      result.add expandDefault(t.elementType, info)
+  of tyPtr, tyRef, tyProc, tyPointer, tyCstring:
+    result = newZero(t, info, nkNilLit)
+  of tyVar, tyLent:
+    let e = t.elementType
+    if e.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
+      # skip the modifier, `var openArray` is a (ptr, len) pair too:
+      result = expandDefault(e, info)
+    else:
+      result = newZero(e, info, nkNilLit)
+  of tySet:
+    result = newZero(t, info, nkCurly)
+  of tyObject:
+    result = newNodeIT(nkObjConstr, info, t)
+    result.add newNodeIT(nkType, info, t)
+    expandDefaultObj(t, info, result)
+  of tyTuple:
+    result = newZero(t, info, nkTupleConstr)
+    for it in t.kids:
+      result.add expandDefault(it, info)
+  of tyVarargs, tyOpenArray, tySequence, tyUncheckedArray:
+    result = newZero(t, info, nkBracket)
+  of tyString:
+    result = newZero(t, info, nkStrLit)
+  of tyNone, tyEmpty, tyUntyped, tyTyped, tyTypeDesc,
+     tyNil, tyGenericInvocation, tyProxy, tyBuiltInTypeClass,
+     tyUserTypeClass, tyUserTypeClassInst, tyCompositeTypeClass,
+     tyAnd, tyOr, tyNot, tyAnything, tyConcept, tyIterable, tyForward:
+    result = newZero(t, info, nkEmpty) # bug indicator

compiler/extccomp.nim

@@ -14,12 +14,14 @@
 
 import ropes, platform, condsyms, options, msgs, lineinfos, pathutils, modulepaths
 
-import std/[os, osproc, sha1, streams, sequtils, times, strtabs, json, jsonutils, sugar, parseutils]
+import std/[os, osproc, streams, sequtils, times, strtabs, json, jsonutils, sugar, parseutils]
 
 import std / strutils except addf
 
 when defined(nimPreviewSlimSystem):
-  import std/syncio
+  import std/[syncio, assertions]
+
+import ../dist/checksums/src/checksums/sha1
 
 type
   TInfoCCProp* = enum         # properties of the C compiler:
@@ -31,6 +33,7 @@ type
     hasGnuAsm,                # CC's asm uses the absurd GNU assembler syntax
     hasDeclspec,              # CC has __declspec(X)
     hasAttribute,             # CC has __attribute__((X))
+    hasBuiltinUnreachable     # CC has __builtin_unreachable
   TInfoCCProps* = set[TInfoCCProp]
   TInfoCC* = tuple[
     name: string,        # the short name of the compiler
@@ -93,7 +96,7 @@ compiler gcc:
     produceAsm: gnuAsmListing,
     cppXsupport: "-std=gnu++17 -funsigned-char",
     props: {hasSwitchRange, hasComputedGoto, hasCpp, hasGcGuard, hasGnuAsm,
-            hasAttribute})
+            hasAttribute, hasBuiltinUnreachable})
 
 # GNU C and C++ Compiler
 compiler nintendoSwitchGCC:
@@ -120,7 +123,7 @@ compiler nintendoSwitchGCC:
     produceAsm: gnuAsmListing,
     cppXsupport: "-std=gnu++17 -funsigned-char",
     props: {hasSwitchRange, hasComputedGoto, hasCpp, hasGcGuard, hasGnuAsm,
-            hasAttribute})
+            hasAttribute, hasBuiltinUnreachable})
 
 # LLVM Frontend for GCC/G++
 compiler llvmGcc:
@@ -316,7 +319,7 @@ proc getConfigVar(conf: ConfigRef; c: TSystemCC, suffix: string): string =
   var fullSuffix = suffix
   case conf.backend
   of backendCpp, backendJs, backendObjc: fullSuffix = "." & $conf.backend & suffix
-  of backendC: discard
+  of backendC, backendNir: discard
   of backendInvalid:
     # during parsing of cfg files; we don't know the backend yet, no point in
     # guessing wrong thing
@@ -484,6 +487,10 @@ proc vccplatform(conf: ConfigRef): string =
         of cpuArm: " --platform:arm"
         of cpuAmd64: " --platform:amd64"
         else: ""
+    else:
+      result = ""
+  else:
+    result = ""
 
 proc getLinkOptions(conf: ConfigRef): string =
   result = conf.linkOptions & " " & conf.linkOptionsCmd & " "
@@ -532,7 +539,7 @@ proc ccHasSaneOverflow*(conf: ConfigRef): bool =
     # NOTE: should we need the full version, use -dumpfullversion
     let (s, exitCode) = try: execCmdEx(exe & " -dumpversion") except IOError, OSError, ValueError: ("", 1)
     if exitCode == 0:
-      var major: int
+      var major: int = 0
       discard parseInt(s, major)
       result = major >= 5
   else:
@@ -578,7 +585,7 @@ proc getCompileCFileCmd*(conf: ConfigRef; cfile: Cfile,
 
     compilePattern = joinPath(conf.cCompilerPath, exe)
   else:
-    compilePattern = getCompilerExe(conf, c, isCpp)
+    compilePattern = exe
 
   includeCmd.add(join([CC[c].includeCmd, quoteShell(conf.projectPath.string)]))
 
@@ -642,7 +649,7 @@ proc externalFileChanged(conf: ConfigRef; cfile: Cfile): bool =
 
   let hashFile = toGeneratedFile(conf, conf.mangleModuleName(cfile.cname).AbsoluteFile, "sha1")
   let currentHash = footprint(conf, cfile)
-  var f: File
+  var f: File = default(File)
   if open(f, hashFile.string, fmRead):
     let oldHash = parseSecureHash(f.readLine())
     close(f)
@@ -777,6 +784,7 @@ template tryExceptOSErrorMessage(conf: ConfigRef; errorPrefix: string = "", body
     raise
 
 proc getExtraCmds(conf: ConfigRef; output: AbsoluteFile): seq[string] =
+  result = @[]
   when defined(macosx):
     if optCDebug in conf.globalOptions and optGenStaticLib notin conf.globalOptions:
       # if needed, add an option to skip or override location
@@ -832,7 +840,10 @@ proc linkViaResponseFile(conf: ConfigRef; cmd: string) =
   else:
     writeFile(linkerArgs, args)
   try:
-    execLinkCmd(conf, cmd.substr(0, last) & " @" & linkerArgs)
+    when defined(macosx):
+      execLinkCmd(conf, "xargs " & cmd.substr(0, last) & " < " & linkerArgs)
+    else:
+      execLinkCmd(conf, cmd.substr(0, last) & " @" & linkerArgs)
   finally:
     removeFile(linkerArgs)
 
@@ -856,6 +867,7 @@ proc hcrLinkTargetName(conf: ConfigRef, objFile: string, isMain = false): Absolu
   result = conf.getNimcacheDir / RelativeFile(targetName)
 
 proc displayProgressCC(conf: ConfigRef, path, compileCmd: string): string =
+  result = ""
   if conf.hasHint(hintCC):
     if optListCmd in conf.globalOptions or conf.verbosity > 1:
       result = MsgKindToStr[hintCC] % (demangleModuleName(path.splitFile.name) & ": " & compileCmd)
@@ -878,15 +890,15 @@ proc preventLinkCmdMaxCmdLen(conf: ConfigRef, linkCmd: string) =
 
 proc callCCompiler*(conf: ConfigRef) =
   var
-    linkCmd: string
+    linkCmd: string = ""
     extraCmds: seq[string]
   if conf.globalOptions * {optCompileOnly, optGenScript} == {optCompileOnly}:
     return # speed up that call if only compiling and no script shall be
            # generated
   #var c = cCompiler
   var script: Rope = ""
-  var cmds: TStringSeq
-  var prettyCmds: TStringSeq
+  var cmds: TStringSeq = default(TStringSeq)
+  var prettyCmds: TStringSeq = default(TStringSeq)
   let prettyCb = proc (idx: int) = writePrettyCmdsStderr(prettyCmds[idx])
 
   for idx, it in conf.toCompile:
@@ -987,7 +999,7 @@ type BuildCache = object
   depfiles: seq[(string, string)]
   nimexe: string
 
-proc writeJsonBuildInstructions*(conf: ConfigRef) =
+proc writeJsonBuildInstructions*(conf: ConfigRef; deps: StringTableRef) =
   var linkFiles = collect(for it in conf.externalToLink:
     var it = it
     if conf.noAbsolutePaths: it = it.extractFilename
@@ -1008,17 +1020,22 @@ proc writeJsonBuildInstructions*(conf: ConfigRef) =
     currentDir: getCurrentDir())
   if optRun in conf.globalOptions or isDefined(conf, "nimBetterRun"):
     bcache.cmdline = conf.commandLine
-    bcache.depfiles = collect(for it in conf.m.fileInfos:
+    for it in conf.m.fileInfos:
       let path = it.fullPath.string
       if isAbsolute(path): # TODO: else?
-        (path, $secureHashFile(path)))
+        if path in deps:
+          bcache.depfiles.add (path, deps[path])
+        else: # backup for configs etc.
+          bcache.depfiles.add (path, $secureHashFile(path))
+
     bcache.nimexe = hashNimExe()
   conf.jsonBuildFile = conf.jsonBuildInstructionsFile
   conf.jsonBuildFile.string.writeFile(bcache.toJson.pretty)
 
 proc changeDetectedViaJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile): bool =
+  result = false
   if not fileExists(jsonFile) or not fileExists(conf.absOutFile): return true
-  var bcache: BuildCache
+  var bcache: BuildCache = default(BuildCache)
   try: bcache.fromJson(jsonFile.string.parseFile)
   except IOError, OSError, ValueError:
     stderr.write "Warning: JSON processing failed for: $#\n" % jsonFile.string
@@ -1034,7 +1051,7 @@ proc changeDetectedViaJsonBuildInstructions*(conf: ConfigRef; jsonFile: Absolute
     if $secureHashFile(file) != hash: return true
 
 proc runJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile) =
-  var bcache: BuildCache
+  var bcache: BuildCache = default(BuildCache)
   try: bcache.fromJson(jsonFile.string.parseFile)
   except ValueError, KeyError, JsonKindError:
     let e = getCurrentException()
@@ -1047,7 +1064,8 @@ proc runJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile) =
     globalError(conf, gCmdLineInfo,
       "jsonscript command outputFile '$1' must match '$2' which was specified during --compileOnly, see \"outputFile\" entry in '$3' " %
       [outputCurrent, output, jsonFile.string])
-  var cmds, prettyCmds: TStringSeq
+  var cmds: 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
@@ -1057,6 +1075,7 @@ proc runJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile) =
   for cmd in bcache.extraCmds: execExternalProgram(conf, cmd, hintExecuting)
 
 proc genMappingFiles(conf: ConfigRef; list: CfileList): Rope =
+  result = ""
   for it in list:
     result.addf("--file:r\"$1\"$N", [rope(it.cname.string)])
 

compiler/filter_tmpl.nim

@@ -10,9 +10,11 @@
 # This module implements Nim's standard template filter.
 
 import
-  llstream, strutils, ast, msgs, options,
+  llstream, ast, msgs, options,
   filters, lineinfos, pathutils
 
+import std/strutils
+
 type
   TParseState = enum
     psDirective, psTempl
@@ -201,17 +203,15 @@ proc parseLine(p: var TTmplParser) =
 
 proc filterTmpl*(conf: ConfigRef, stdin: PLLStream, filename: AbsoluteFile,
                  call: PNode): PLLStream =
-  var p: TTmplParser
-  p.config = conf
-  p.info = newLineInfo(conf, filename, 0, 0)
-  p.outp = llStreamOpen("")
-  p.inp = stdin
-  p.subsChar = charArg(conf, call, "subschar", 1, '$')
-  p.nimDirective = charArg(conf, call, "metachar", 2, '#')
-  p.emit = strArg(conf, call, "emit", 3, "result.add")
-  p.conc = strArg(conf, call, "conc", 4, " & ")
-  p.toStr = strArg(conf, call, "tostring", 5, "$")
-  p.x = newStringOfCap(120)
+  var p = TTmplParser(config: conf, info: newLineInfo(conf, filename, 0, 0),
+                outp: llStreamOpen(""), inp: stdin,
+                subsChar: charArg(conf, call, "subschar", 1, '$'),
+                nimDirective: charArg(conf, call, "metachar", 2, '#'),
+                emit: strArg(conf, call, "emit", 3, "result.add"),
+                conc: strArg(conf, call, "conc", 4, " & "),
+                toStr: strArg(conf, call, "tostring", 5, "$"),
+                x: newStringOfCap(120)
+                )
   # do not process the first line which contains the directive:
   if llStreamReadLine(p.inp, p.x):
     inc p.info.line

compiler/filters.nim

@@ -10,9 +10,11 @@
 # This module implements Nim's simple filters and helpers for filters.
 
 import
-  llstream, idents, strutils, ast, msgs, options,
+  llstream, idents, ast, msgs, options,
   renderer, pathutils
 
+import std/strutils
+
 proc invalidPragma(conf: ConfigRef; n: PNode) =
   localError(conf, n.info,
       "'$1' not allowed here" % renderTree(n, {renderNoComments}))
@@ -29,23 +31,30 @@ proc getArg(conf: ConfigRef; n: PNode, name: string, pos: int): PNode =
       return n[i]
 
 proc charArg*(conf: ConfigRef; n: PNode, name: string, pos: int, default: char): char =
+
   var x = getArg(conf, n, name, pos)
   if x == nil: result = default
   elif x.kind == nkCharLit: result = chr(int(x.intVal))
-  else: invalidPragma(conf, n)
+  else:
+    result = default(char)
+    invalidPragma(conf, n)
 
 proc strArg*(conf: ConfigRef; n: PNode, name: string, pos: int, default: string): string =
   var x = getArg(conf, n, name, pos)
   if x == nil: result = default
   elif x.kind in {nkStrLit..nkTripleStrLit}: result = x.strVal
-  else: invalidPragma(conf, n)
+  else:
+    result = ""
+    invalidPragma(conf, n)
 
 proc boolArg*(conf: ConfigRef; n: PNode, name: string, pos: int, default: bool): bool =
   var x = getArg(conf, n, name, pos)
   if x == nil: result = default
   elif x.kind == nkIdent and cmpIgnoreStyle(x.ident.s, "true") == 0: result = true
   elif x.kind == nkIdent and cmpIgnoreStyle(x.ident.s, "false") == 0: result = false
-  else: invalidPragma(conf, n)
+  else:
+    result = false
+    invalidPragma(conf, n)
 
 proc filterStrip*(conf: ConfigRef; stdin: PLLStream, filename: AbsoluteFile, call: PNode): PLLStream =
   var pattern = strArg(conf, call, "startswith", 1, "")

compiler/gorgeimpl.nim

@@ -9,12 +9,15 @@
 
 ## Module that implements ``gorge`` for the compiler.
 
-import msgs, std / sha1, os, osproc, streams, options,
-  lineinfos, pathutils
+import msgs, options, lineinfos, pathutils
+
+import std/[os, osproc, streams]
 
 when defined(nimPreviewSlimSystem):
   import std/syncio
 
+import ../dist/checksums/src/checksums/sha1
+
 proc readOutput(p: Process): (string, int) =
   result[0] = ""
   var output = p.outputStream
@@ -27,10 +30,11 @@ proc readOutput(p: Process): (string, int) =
 
 proc opGorge*(cmd, input, cache: string, info: TLineInfo; conf: ConfigRef): (string, int) =
   let workingDir = parentDir(toFullPath(conf, info))
+  result = ("", 0)
   if cache.len > 0:
     let h = secureHash(cmd & "\t" & input & "\t" & cache)
     let filename = toGeneratedFile(conf, AbsoluteFile("gorge_" & $h), "txt").string
-    var f: File
+    var f: File = default(File)
     if optForceFullMake notin conf.globalOptions and open(f, filename):
       result = (f.readAll, 0)
       f.close

compiler/guards.nim

@@ -51,6 +51,10 @@ proc isLet(n: PNode): bool =
     elif n.sym.kind == skParam and skipTypes(n.sym.typ,
                                              abstractInst).kind notin {tyVar}:
       result = true
+    else:
+      result = false
+  else:
+    result = false
 
 proc isVar(n: PNode): bool =
   n.kind == nkSym and n.sym.kind in {skResult, skVar} and
@@ -136,6 +140,8 @@ proc neg(n: PNode; o: Operators): PNode =
       result = a
     elif b != nil:
       result = b
+    else:
+      result = nil
   else:
     # leave  not (a == 4)  as it is
     result = newNodeI(nkCall, n.info, 2)
@@ -330,6 +336,8 @@ proc usefulFact(n: PNode; o: Operators): PNode =
         result = n
       elif n[1].getMagic in someLen or n[2].getMagic in someLen:
         result = n
+      else:
+        result = nil
   of someLe+someLt:
     if isLetLocation(n[1], true) or isLetLocation(n[2], true):
       # XXX algebraic simplifications!  'i-1 < a.len' --> 'i < a.len+1'
@@ -337,12 +345,18 @@ proc usefulFact(n: PNode; o: Operators): PNode =
     elif n[1].getMagic in someLen or n[2].getMagic in someLen:
       # XXX Rethink this whole idea of 'usefulFact' for semparallel
       result = n
+    else:
+      result = nil
   of mIsNil:
     if isLetLocation(n[1], false) or isVar(n[1]):
       result = n
+    else:
+      result = nil
   of someIn:
     if isLetLocation(n[1], true):
       result = n
+    else:
+      result = nil
   of mAnd:
     let
       a = usefulFact(n[1], o)
@@ -356,10 +370,14 @@ proc usefulFact(n: PNode; o: Operators): PNode =
       result = a
     elif b != nil:
       result = b
+    else:
+      result = nil
   of mNot:
     let a = usefulFact(n[1], o)
     if a != nil:
       result = a.neg(o)
+    else:
+      result = nil
   of mOr:
     # 'or' sucks! (p.isNil or q.isNil) --> hard to do anything
     # with that knowledge...
@@ -376,6 +394,8 @@ proc usefulFact(n: PNode; o: Operators): PNode =
       result[1] = a
       result[2] = b
       result = result.neg(o)
+    else:
+      result = nil
   elif n.kind == nkSym and n.sym.kind == skLet:
     # consider:
     #   let a = 2 < x
@@ -384,8 +404,12 @@ proc usefulFact(n: PNode; o: Operators): PNode =
     # We make can easily replace 'a' by '2 < x' here:
     if n.sym.astdef != nil:
       result = usefulFact(n.sym.astdef, o)
+    else:
+      result = nil
   elif n.kind == nkStmtListExpr:
     result = usefulFact(n.lastSon, o)
+  else:
+    result = nil
 
 type
   TModel* = object
@@ -451,8 +475,9 @@ proc hasSubTree(n, x: PNode): bool =
     of nkEmpty..nkNilLit:
       result = n.sameTree(x)
     of nkFormalParams:
-      discard
+      result = false
     else:
+      result = false
       for i in 0..<n.len:
         if hasSubTree(n[i], x): return true
 
@@ -483,6 +508,8 @@ proc invalidateFacts*(m: var TModel, n: PNode) =
 proc valuesUnequal(a, b: PNode): bool =
   if a.isValue and b.isValue:
     result = not sameValue(a, b)
+  else:
+    result = false
 
 proc impliesEq(fact, eq: PNode): TImplication =
   let (loc, val) = if isLocation(eq[1]): (1, 2) else: (2, 1)
@@ -493,16 +520,26 @@ proc impliesEq(fact, eq: PNode): TImplication =
       # this is not correct; consider:  a == b;  a == 1 --> unknown!
       if sameTree(fact[2], eq[val]): result = impYes
       elif valuesUnequal(fact[2], eq[val]): result = impNo
+      else:
+        result = impUnknown
     elif sameTree(fact[2], eq[loc]):
       if sameTree(fact[1], eq[val]): result = impYes
       elif valuesUnequal(fact[1], eq[val]): result = impNo
+      else:
+        result = impUnknown
+    else:
+      result = impUnknown
   of mInSet:
     # remember: mInSet is 'contains' so the set comes first!
     if sameTree(fact[2], eq[loc]) and isValue(eq[val]):
       if inSet(fact[1], eq[val]): result = impYes
       else: result = impNo
-  of mNot, mOr, mAnd: assert(false, "impliesEq")
-  else: discard
+    else:
+      result = impUnknown
+  of mNot, mOr, mAnd:
+    result = impUnknown
+    assert(false, "impliesEq")
+  else: result = impUnknown
 
 proc leImpliesIn(x, c, aSet: PNode): TImplication =
   if c.kind in {nkCharLit..nkUInt64Lit}:
@@ -512,13 +549,19 @@ proc leImpliesIn(x, c, aSet: PNode): TImplication =
     var value = newIntNode(c.kind, firstOrd(nil, x.typ))
     # don't iterate too often:
     if c.intVal - value.intVal < 1000:
-      var i, pos, neg: int
+      var i, pos, neg: int = 0
       while value.intVal <= c.intVal:
         if inSet(aSet, value): inc pos
         else: inc neg
         inc i; inc value.intVal
       if pos == i: result = impYes
       elif neg == i: result = impNo
+      else:
+        result = impUnknown
+    else:
+      result = impUnknown
+  else:
+    result = impUnknown
 
 proc geImpliesIn(x, c, aSet: PNode): TImplication =
   if c.kind in {nkCharLit..nkUInt64Lit}:
@@ -529,17 +572,23 @@ proc geImpliesIn(x, c, aSet: PNode): TImplication =
     let max = lastOrd(nil, x.typ)
     # don't iterate too often:
     if max - getInt(value) < toInt128(1000):
-      var i, pos, neg: int
+      var i, pos, neg: int = 0
       while value.intVal <= max:
         if inSet(aSet, value): inc pos
         else: inc neg
         inc i; inc value.intVal
       if pos == i: result = impYes
       elif neg == i: result = impNo
+      else: result = impUnknown
+    else:
+      result = impUnknown
+  else:
+    result = impUnknown
 
 proc compareSets(a, b: PNode): TImplication =
   if equalSets(nil, a, b): result = impYes
   elif intersectSets(nil, a, b).len == 0: result = impNo
+  else: result = impUnknown
 
 proc impliesIn(fact, loc, aSet: PNode): TImplication =
   case fact[0].sym.magic
@@ -550,22 +599,32 @@ proc impliesIn(fact, loc, aSet: PNode): TImplication =
     elif sameTree(fact[2], loc):
       if inSet(aSet, fact[1]): result = impYes
       else: result = impNo
+    else:
+      result = impUnknown
   of mInSet:
     if sameTree(fact[2], loc):
       result = compareSets(fact[1], aSet)
+    else:
+      result = impUnknown
   of someLe:
     if sameTree(fact[1], loc):
       result = leImpliesIn(fact[1], fact[2], aSet)
     elif sameTree(fact[2], loc):
       result = geImpliesIn(fact[2], fact[1], aSet)
+    else:
+      result = impUnknown
   of someLt:
     if sameTree(fact[1], loc):
       result = leImpliesIn(fact[1], fact[2].pred, aSet)
     elif sameTree(fact[2], loc):
       # 4 < x  -->  3 <= x
       result = geImpliesIn(fact[2], fact[1].pred, aSet)
-  of mNot, mOr, mAnd: assert(false, "impliesIn")
-  else: discard
+    else:
+      result = impUnknown
+  of mNot, mOr, mAnd:
+    result = impUnknown
+    assert(false, "impliesIn")
+  else: result = impUnknown
 
 proc valueIsNil(n: PNode): TImplication =
   if n.kind == nkNilLit: impYes
@@ -577,13 +636,19 @@ proc impliesIsNil(fact, eq: PNode): TImplication =
   of mIsNil:
     if sameTree(fact[1], eq[1]):
       result = impYes
+    else:
+      result = impUnknown
   of someEq:
     if sameTree(fact[1], eq[1]):
       result = valueIsNil(fact[2].skipConv)
     elif sameTree(fact[2], eq[1]):
       result = valueIsNil(fact[1].skipConv)
-  of mNot, mOr, mAnd: assert(false, "impliesIsNil")
-  else: discard
+    else:
+      result = impUnknown
+  of mNot, mOr, mAnd:
+    result = impUnknown
+    assert(false, "impliesIsNil")
+  else: result = impUnknown
 
 proc impliesGe(fact, x, c: PNode): TImplication =
   assert isLocation(x)
@@ -594,32 +659,57 @@ proc impliesGe(fact, x, c: PNode): TImplication =
         # fact:  x = 4;  question x >= 56? --> true iff 4 >= 56
         if leValue(c, fact[2]): result = impYes
         else: result = impNo
+      else:
+        result = impUnknown
     elif sameTree(fact[2], x):
       if isValue(fact[1]) and isValue(c):
         if leValue(c, fact[1]): result = impYes
         else: result = impNo
+      else:
+        result = impUnknown
+    else:
+      result = impUnknown
   of someLt:
     if sameTree(fact[1], x):
       if isValue(fact[2]) and isValue(c):
         # fact:  x < 4;  question N <= x? --> false iff N <= 4
         if leValue(fact[2], c): result = impNo
+        else: result = impUnknown
         # fact:  x < 4;  question 2 <= x? --> we don't know
+      else:
+        result = impUnknown
     elif sameTree(fact[2], x):
       # fact: 3 < x; question: N-1 < x ?  --> true iff N-1 <= 3
       if isValue(fact[1]) and isValue(c):
         if leValue(c.pred, fact[1]): result = impYes
+        else: result = impUnknown
+      else:
+        result = impUnknown
+    else:
+      result = impUnknown
   of someLe:
     if sameTree(fact[1], x):
       if isValue(fact[2]) and isValue(c):
         # fact:  x <= 4;  question x >= 56? --> false iff 4 <= 56
         if leValue(fact[2], c): result = impNo
         # fact:  x <= 4;  question x >= 2? --> we don't know
+        else:
+          result = impUnknown
+      else:
+        result = impUnknown
     elif sameTree(fact[2], x):
       # fact: 3 <= x; question: x >= 2 ?  --> true iff 2 <= 3
       if isValue(fact[1]) and isValue(c):
         if leValue(c, fact[1]): result = impYes
-  of mNot, mOr, mAnd: assert(false, "impliesGe")
-  else: discard
+        else: result = impUnknown
+      else:
+        result = impUnknown
+    else:
+      result = impUnknown
+  of mNot, mOr, mAnd:
+    result = impUnknown
+    assert(false, "impliesGe")
+  else: result = impUnknown
 
 proc impliesLe(fact, x, c: PNode): TImplication =
   if not isLocation(x):
@@ -634,35 +724,59 @@ proc impliesLe(fact, x, c: PNode): TImplication =
         # fact:  x = 4;  question x <= 56? --> true iff 4 <= 56
         if leValue(fact[2], c): result = impYes
         else: result = impNo
+      else:
+        result = impUnknown
     elif sameTree(fact[2], x):
       if isValue(fact[1]) and isValue(c):
         if leValue(fact[1], c): result = impYes
         else: result = impNo
+      else:
+        result = impUnknown
+    else:
+      result = impUnknown
   of someLt:
     if sameTree(fact[1], x):
       if isValue(fact[2]) and isValue(c):
         # fact:  x < 4;  question x <= N? --> true iff N-1 <= 4
         if leValue(fact[2], c.pred): result = impYes
+        else:
+          result = impUnknown
         # fact:  x < 4;  question x <= 2? --> we don't know
+      else:
+        result = impUnknown
     elif sameTree(fact[2], x):
       # fact: 3 < x; question: x <= 1 ?  --> false iff 1 <= 3
       if isValue(fact[1]) and isValue(c):
         if leValue(c, fact[1]): result = impNo
-
+        else: result = impUnknown
+      else:
+        result = impUnknown
+    else:
+      result = impUnknown
   of someLe:
     if sameTree(fact[1], x):
       if isValue(fact[2]) and isValue(c):
         # fact:  x <= 4;  question x <= 56? --> true iff 4 <= 56
         if leValue(fact[2], c): result = impYes
+        else: result = impUnknown
         # fact:  x <= 4;  question x <= 2? --> we don't know
+      else:
+        result = impUnknown
 
     elif sameTree(fact[2], x):
       # fact: 3 <= x; question: x <= 2 ?  --> false iff 2 < 3
       if isValue(fact[1]) and isValue(c):
         if leValue(c, fact[1].pred): result = impNo
+        else:result = impUnknown
+      else:
+        result = impUnknown
+    else:
+      result = impUnknown
 
-  of mNot, mOr, mAnd: assert(false, "impliesLe")
-  else: discard
+  of mNot, mOr, mAnd:
+    result = impUnknown
+    assert(false, "impliesLe")
+  else: result = impUnknown
 
 proc impliesLt(fact, x, c: PNode): TImplication =
   # x < 3  same as x <= 2:
@@ -674,6 +788,8 @@ proc impliesLt(fact, x, c: PNode): TImplication =
     let q = x.pred
     if q != x:
       result = impliesLe(fact, q, c)
+    else:
+      result = impUnknown
 
 proc `~`(x: TImplication): TImplication =
   case x
@@ -725,6 +841,7 @@ proc factImplies(fact, prop: PNode): TImplication =
 
 proc doesImply*(facts: TModel, prop: PNode): TImplication =
   assert prop.kind in nkCallKinds
+  result = impUnknown
   for f in facts.s:
     # facts can be invalidated, in which case they are 'nil':
     if not f.isNil:
@@ -753,7 +870,7 @@ template isSub(x): untyped = x.getMagic in someSub
 template isVal(x): untyped = x.kind in {nkCharLit..nkUInt64Lit}
 template isIntVal(x, y): untyped = x.intVal == y
 
-import macros
+import std/macros
 
 macro `=~`(x: PNode, pat: untyped): bool =
   proc m(x, pat, conds: NimNode) =
@@ -900,6 +1017,7 @@ proc applyReplacements(n: PNode; rep: TReplacements): PNode =
 
 proc pleViaModelRec(m: var TModel; a, b: PNode): TImplication =
   # now check for inferrable facts: a <= b and b <= c  implies a <= c
+  result = impUnknown
   for i in 0..m.s.high:
     let fact = m.s[i]
     if fact != nil and fact.getMagic in someLe:
@@ -945,7 +1063,7 @@ proc pleViaModel(model: TModel; aa, bb: PNode): TImplication =
       let b = fact[2]
       if a.kind == nkSym: replacements.add((a,b))
       else: replacements.add((b,a))
-  var m: TModel
+  var m = TModel()
   var a = aa
   var b = bb
   if replacements.len > 0:
@@ -980,8 +1098,8 @@ proc addFactLt*(m: var TModel; a, b: PNode) =
   addFactLe(m, a, bb)
 
 proc settype(n: PNode): PType =
-  result = newType(tySet, ItemId(module: -1, item: -1), n.typ.owner)
-  var idgen: IdGenerator
+  var idgen = idGeneratorForPackage(-1'i32)
+  result = newType(tySet, idgen, n.typ.owner)
   addSonSkipIntLit(result, n.typ, idgen)
 
 proc buildOf(it, loc: PNode; o: Operators): PNode =

compiler/hlo.nim

@@ -10,9 +10,6 @@
 # This include implements the high level optimization pass.
 # included from sem.nim
 
-when defined(nimPreviewSlimSystem):
-  import std/assertions
-
 proc hlo(c: PContext, n: PNode): PNode
 
 proc evalPattern(c: PContext, n, orig: PNode): PNode =
@@ -20,9 +17,11 @@ proc evalPattern(c: PContext, n, orig: PNode): PNode =
   # we need to ensure that the resulting AST is semchecked. However, it's
   # awful to semcheck before macro invocation, so we don't and treat
   # templates and macros as immediate in this context.
-  var rule: string
-  if c.config.hasHint(hintPattern):
-    rule = renderTree(n, {renderNoComments})
+  var rule: string =
+    if c.config.hasHint(hintPattern):
+      renderTree(n, {renderNoComments})
+    else:
+      ""
   let s = n[0].sym
   case s.kind
   of skMacro:
@@ -73,7 +72,7 @@ proc hlo(c: PContext, n: PNode): PNode =
   else:
     if n.kind in {nkFastAsgn, nkAsgn, nkSinkAsgn, nkIdentDefs, nkVarTuple} and
         n[0].kind == nkSym and
-        {sfGlobal, sfPure} * n[0].sym.flags == {sfGlobal, sfPure}:
+        {sfGlobal, sfPure} <= n[0].sym.flags:
       # do not optimize 'var g {.global} = re(...)' again!
       return n
     result = applyPatterns(c, n)

compiler/ic/bitabs.nim

@@ -1,7 +1,8 @@
 ## A BiTable is a table that can be seen as an optimized pair
 ## of `(Table[LitId, Val], Table[Val, LitId])`.
 
-import hashes, rodfiles
+import std/hashes
+import rodfiles
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -13,6 +14,8 @@ type
     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
 
@@ -33,9 +36,7 @@ proc mustRehash(length, counter: int): bool {.inline.} =
   result = (length * 2 < counter * 3) or (length - counter < 4)
 
 const
-  idStart = 256 ##
-  ## Ids do not start with 0 but with this value. The IR needs it.
-  ## TODO: explain why
+  idStart = 1
 
 template idToIdx(x: LitId): int = x.int - idStart
 
@@ -118,6 +119,12 @@ 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]

compiler/ic/cbackend.nim

@@ -18,7 +18,7 @@
 ## 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
+import std/[packedsets, algorithm, tables]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -51,6 +51,8 @@ proc generateCodeForModule(g: ModuleGraph; m: var LoadedModule; alive: var Alive
     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) =
@@ -98,7 +100,7 @@ proc aliveSymsChanged(config: ConfigRef; position: int; alive: AliveSyms): bool
   var f2 = rodfiles.open(asymFile.string)
   f2.loadHeader()
   f2.loadSection aliveSymsSection
-  var oldData: seq[int32]
+  var oldData: seq[int32] = @[]
   f2.loadSeq(oldData)
   f2.close
   if f2.err == ok and oldData == s:
@@ -144,12 +146,12 @@ proc generateCode*(g: ModuleGraph) =
   var alive = computeAliveSyms(g.packed, g.config)
 
   when false:
-    for i in 0..high(g.packed):
+    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..high(g.packed):
+  for i in 0..<len(g.packed):
     # case statement here to enforce exhaustive checks.
     case g.packed[i].status
     of undefined:
@@ -171,7 +173,7 @@ proc generateCode*(g: ModuleGraph) =
   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..high(g.packed):
+  for i in 0..<len(g.packed):
     if i != mainModuleIdx:
       genPackedModule(g, i, alive)
   if mainModuleIdx >= 0:

compiler/ic/dce.nim

@@ -40,10 +40,14 @@ proc isExportedToC(c: var AliveContext; g: PackedModuleGraph; symId: int32): boo
     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
 
@@ -105,13 +109,13 @@ proc aliveCode(c: var AliveContext; g: PackedModuleGraph; tree: PackedTree; n: N
     discard "ignore non-sym atoms"
   of nkSym:
     # This symbol is alive and everything its body references.
-    followLater(c, g, c.thisModule, n.operand)
+    followLater(c, g, c.thisModule, tree[n].soperand)
   of nkModuleRef:
     let (n1, n2) = sons2(tree, n)
-    assert n1.kind == nkInt32Lit
-    assert n2.kind == nkInt32Lit
+    assert n1.kind == nkNone
+    assert n2.kind == nkNone
     let m = n1.litId
-    let item = n2.operand
+    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,
@@ -127,7 +131,7 @@ proc aliveCode(c: var AliveContext; g: PackedModuleGraph; tree: PackedTree; n: N
     rangeCheckAnalysis(c, g, tree, n)
   of nkProcDef, nkConverterDef, nkMethodDef, nkFuncDef, nkIteratorDef:
     if n.firstSon.kind == nkSym and isNotGeneric(n):
-      let item = n.firstSon.operand
+      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)
@@ -149,7 +153,7 @@ proc computeAliveSyms*(g: PackedModuleGraph; conf: ConfigRef): AliveSyms =
   var c = AliveContext(stack: @[], decoder: PackedDecoder(config: conf),
                        thisModule: -1, alive: newSeq[IntSet](g.len),
                        options: conf.options)
-  for i in countdown(high(g), 0):
+  for i in countdown(len(g)-1, 0):
     if g[i].status != undefined:
       c.thisModule = i
       for p in allNodes(g[i].fromDisk.topLevel):

compiler/ic/ic.nim

@@ -7,12 +7,16 @@
 #    distribution, for details about the copyright.
 #
 
-import hashes, tables, intsets, std/sha1
+import std/[hashes, tables, intsets, monotimes]
 import packed_ast, bitabs, rodfiles
 import ".." / [ast, idents, lineinfos, msgs, ropes, options,
   pathutils, condsyms, packages, modulepaths]
 #import ".." / [renderer, astalgo]
-from os import removeFile, isAbsolute
+from std/os import removeFile, isAbsolute
+
+import ../../dist/checksums/src/checksums/sha1
+
+import ".." / nir / nirlineinfos
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions, formatfloat]
@@ -39,16 +43,18 @@ type
     bodies*: PackedTree # other trees. Referenced from typ.n and sym.ast by their position.
     #producedGenerics*: Table[GenericKey, SymId]
     exports*: seq[(LitId, int32)]
-    hidden*: seq[(LitId, int32)]
-    reexports*: seq[(LitId, PackedItemId)]
+    hidden: seq[(LitId, int32)]
+    reexports: seq[(LitId, PackedItemId)]
     compilerProcs*: seq[(LitId, int32)]
     converters*, methods*, trmacros*, pureEnums*: seq[int32]
 
     typeInstCache*: seq[(PackedItemId, PackedItemId)]
     procInstCache*: seq[PackedInstantiation]
     attachedOps*: seq[(PackedItemId, TTypeAttachedOp, PackedItemId)]
-    methodsPerType*: seq[(PackedItemId, int, PackedItemId)]
+    methodsPerGenericType*: seq[(PackedItemId, int, PackedItemId)]
     enumToStringProcs*: seq[(PackedItemId, PackedItemId)]
+    methodsPerType*: seq[(PackedItemId, PackedItemId)]
+    dispatchers*: seq[PackedItemId]
 
     emittedTypeInfo*: seq[string]
     backendFlags*: set[ModuleBackendFlag]
@@ -58,6 +64,7 @@ type
     strings*: BiTable[string] # we could share these between modules.
     numbers*: BiTable[BiggestInt] # we also store floats in here so
                                   # that we can assure that every bit is kept
+    man*: LineInfoManager
 
     cfg: PackedConfig
 
@@ -73,37 +80,36 @@ type
     symMarker*: IntSet #Table[ItemId, SymId]    # ItemId.item -> SymId
     config*: ConfigRef
 
-proc toString*(tree: PackedTree; n: NodePos; m: PackedModule; nesting: int;
+proc toString*(tree: PackedTree; pos: NodePos; m: PackedModule; nesting: int;
                result: var string) =
-  let pos = n.int
   if result.len > 0 and result[^1] notin {' ', '\n'}:
     result.add ' '
 
   result.add $tree[pos].kind
-  case tree.nodes[pos].kind
-  of nkNone, nkEmpty, nkNilLit, nkType: discard
+  case tree[pos].kind
+  of nkEmpty, nkNilLit, nkType: discard
   of nkIdent, nkStrLit..nkTripleStrLit:
     result.add " "
-    result.add m.strings[LitId tree.nodes[pos].operand]
+    result.add m.strings[LitId tree[pos].uoperand]
   of nkSym:
     result.add " "
-    result.add m.strings[m.syms[tree.nodes[pos].operand].name]
+    result.add m.strings[m.syms[tree[pos].soperand].name]
   of directIntLit:
     result.add " "
-    result.addInt tree.nodes[pos].operand
+    result.addInt tree[pos].soperand
   of externSIntLit:
     result.add " "
-    result.addInt m.numbers[LitId tree.nodes[pos].operand]
+    result.addInt m.numbers[LitId tree[pos].uoperand]
   of externUIntLit:
     result.add " "
-    result.addInt cast[uint64](m.numbers[LitId tree.nodes[pos].operand])
+    result.addInt cast[uint64](m.numbers[LitId tree[pos].uoperand])
   of nkFloatLit..nkFloat128Lit:
     result.add " "
-    result.addFloat cast[BiggestFloat](m.numbers[LitId tree.nodes[pos].operand])
+    result.addFloat cast[BiggestFloat](m.numbers[LitId tree[pos].uoperand])
   else:
     result.add "(\n"
     for i in 1..(nesting+1)*2: result.add ' '
-    for child in sonsReadonly(tree, n):
+    for child in sonsReadonly(tree, pos):
       toString(tree, child, m, nesting + 1, result)
     result.add "\n"
     for i in 1..nesting*2: result.add ' '
@@ -229,10 +235,14 @@ proc addImportFileDep*(c: var PackedEncoder; m: var PackedModule; f: FileIndex)
   m.imports.add toLitId(f, c, m)
 
 proc addHidden*(c: var PackedEncoder; m: var PackedModule; s: PSym) =
+  assert s.kind != skUnknown
   let nameId = getOrIncl(m.strings, s.name.s)
   m.hidden.add((nameId, s.itemId.item))
+  assert s.itemId.module == c.thisModule
 
 proc addExported*(c: var PackedEncoder; m: var PackedModule; s: PSym) =
+  assert s.kind != skUnknown
+  assert s.itemId.module == c.thisModule
   let nameId = getOrIncl(m.strings, s.name.s)
   m.exports.add((nameId, s.itemId.item))
 
@@ -251,6 +261,8 @@ proc addMethod*(c: var PackedEncoder; m: var PackedModule; s: PSym) =
   m.methods.add s.itemId.item
 
 proc addReexport*(c: var PackedEncoder; m: var PackedModule; s: PSym) =
+  assert s.kind != skUnknown
+  if s.kind == skModule: return
   let nameId = getOrIncl(m.strings, s.name.s)
   m.reexports.add((nameId, PackedItemId(module: toLitId(s.itemId.module.FileIndex, c, m),
                                         item: s.itemId.item)))
@@ -282,7 +294,8 @@ proc toLitId(x: BiggestInt; m: var PackedModule): LitId =
   result = getOrIncl(m.numbers, x)
 
 proc toPackedInfo(x: TLineInfo; c: var PackedEncoder; m: var PackedModule): PackedLineInfo =
-  PackedLineInfo(line: x.line, col: x.col, file: toLitId(x.fileIndex, c, m))
+  pack(m.man, toLitId(x.fileIndex, c, m), x.line.int32, x.col.int32)
+  #PackedLineInfo(line: x.line, col: x.col, file: toLitId(x.fileIndex, c, m))
 
 proc safeItemId(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId {.inline.} =
   ## given a symbol, produce an ItemId with the correct properties
@@ -334,7 +347,7 @@ proc storeTypeLater(t: PType; c: var PackedEncoder; m: var PackedModule): Packed
 proc storeSymLater(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId =
   if s.isNil: return nilItemId
   assert s.itemId.module >= 0
-  assert s.itemId.module >= 0
+  assert s.itemId.item >= 0
   result = PackedItemId(module: toLitId(s.itemId.module.FileIndex, c, m), item: s.itemId.item)
   if s.itemId.module == c.thisModule:
     # the sym belongs to this module, so serialize it here, eventually.
@@ -357,7 +370,7 @@ proc storeType(t: PType; c: var PackedEncoder; m: var PackedModule): PackedItemI
       paddingAtEnd: t.paddingAtEnd)
     storeNode(p, t, n)
     p.typeInst = t.typeInst.storeType(c, m)
-    for kid in items t.sons:
+    for kid in kids t:
       p.types.add kid.storeType(c, m)
     c.addMissing t.sym
     p.sym = t.sym.safeItemId(c, m)
@@ -370,10 +383,9 @@ proc storeType(t: PType; c: var PackedEncoder; m: var PackedModule): PackedItemI
 proc toPackedLib(l: PLib; c: var PackedEncoder; m: var PackedModule): PackedLib =
   ## the plib hangs off the psym via the .annex field
   if l.isNil: return
-  result.kind = l.kind
-  result.generated = l.generated
-  result.isOverriden = l.isOverriden
-  result.name = toLitId($l.name, m)
+  result = PackedLib(kind: l.kind, generated: l.generated,
+    isOverridden: l.isOverridden, name: toLitId($l.name, m)
+  )
   storeNode(result, l, path)
 
 proc storeSym*(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId =
@@ -390,7 +402,7 @@ proc storeSym*(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId
     assert sfForward notin s.flags
 
     var p = PackedSym(kind: s.kind, flags: s.flags, info: s.info.toPackedInfo(c, m), magic: s.magic,
-      position: s.position, offset: s.offset, options: s.options,
+      position: s.position, offset: s.offset, disamb: s.disamb, options: s.options,
       name: s.name.s.toLitId(m))
 
     storeNode(p, s, ast)
@@ -411,6 +423,7 @@ proc storeSym*(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId
     p.annex = toPackedLib(s.annex, c, m)
     when hasFFI:
       p.cname = toLitId(s.cname, m)
+    p.instantiatedFrom = s.instantiatedFrom.safeItemId(c, m)
 
     # fill the reserved slot, nothing else:
     m.syms[s.itemId.item] = p
@@ -418,53 +431,59 @@ proc storeSym*(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId
 proc addModuleRef(n: PNode; ir: var PackedTree; c: var PackedEncoder; m: var PackedModule) =
   ## add a remote symbol reference to the tree
   let info = n.info.toPackedInfo(c, m)
-  ir.nodes.add PackedNode(kind: nkModuleRef, operand: 3.int32, # spans 3 nodes in total
-                          typeId: storeTypeLater(n.typ, c, m), info: info)
-  ir.nodes.add PackedNode(kind: nkInt32Lit, info: info,
-                          operand: toLitId(n.sym.itemId.module.FileIndex, c, m).int32)
-  ir.nodes.add PackedNode(kind: nkInt32Lit, info: info,
-                          operand: n.sym.itemId.item)
+  if n.typ != n.sym.typ:
+    ir.addNode(kind = nkModuleRef, operand = 3.int32, # spans 3 nodes in total
+               info = info, flags = n.flags,
+               typeId = storeTypeLater(n.typ, c, m))
+  else:
+    ir.addNode(kind = nkModuleRef, operand = 3.int32, # spans 3 nodes in total
+              info = info, flags = n.flags)
+  ir.addNode(kind = nkNone, info = info,
+             operand = toLitId(n.sym.itemId.module.FileIndex, c, m).int32)
+  ir.addNode(kind = nkNone, info = info,
+             operand = n.sym.itemId.item)
 
 proc toPackedNode*(n: PNode; ir: var PackedTree; c: var PackedEncoder; m: var PackedModule) =
   ## serialize a node into the tree
   if n == nil:
-    ir.nodes.add PackedNode(kind: nkNilRodNode, flags: {}, operand: 1)
+    ir.addNode(kind = nkNilRodNode, operand = 1, info = NoLineInfo)
     return
   let info = toPackedInfo(n.info, c, m)
   case n.kind
   of nkNone, nkEmpty, nkNilLit, nkType:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags, operand: 0,
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags, operand = 0,
+               typeId = storeTypeLater(n.typ, c, m), info = info)
   of nkIdent:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32 getOrIncl(m.strings, n.ident.s),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags,
+                operand = int32 getOrIncl(m.strings, n.ident.s),
+                typeId = storeTypeLater(n.typ, c, m), info = info)
   of nkSym:
     if n.sym.itemId.module == c.thisModule:
       # it is a symbol that belongs to the module we're currently
       # packing:
       let id = n.sym.storeSymLater(c, m).item
-      ir.nodes.add PackedNode(kind: nkSym, flags: n.flags, operand: id,
-                              typeId: storeTypeLater(n.typ, c, m), info: info)
+      if n.typ != n.sym.typ:
+        ir.addNode(kind = nkSym, flags = n.flags, operand = id,
+                   info = info,
+                   typeId = storeTypeLater(n.typ, c, m))
+      else:
+        ir.addNode(kind = nkSym, flags = n.flags, operand = id,
+                   info = info)
     else:
       # store it as an external module reference:
       addModuleRef(n, ir, c, m)
-  of directIntLit:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32(n.intVal),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
   of externIntLit:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32 getOrIncl(m.numbers, n.intVal),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags,
+               operand = int32 getOrIncl(m.numbers, n.intVal),
+               typeId = storeTypeLater(n.typ, c, m), info = info)
   of nkStrLit..nkTripleStrLit:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32 getOrIncl(m.strings, n.strVal),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags,
+               operand = int32 getOrIncl(m.strings, n.strVal),
+               typeId = storeTypeLater(n.typ, c, m), info = info)
   of nkFloatLit..nkFloat128Lit:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32 getOrIncl(m.numbers, cast[BiggestInt](n.floatVal)),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags,
+               operand = int32 getOrIncl(m.numbers, cast[BiggestInt](n.floatVal)),
+               typeId = storeTypeLater(n.typ, c, m), info = info)
   else:
     let patchPos = ir.prepare(n.kind, n.flags,
                               storeTypeLater(n.typ, c, m), info)
@@ -489,8 +508,8 @@ proc toPackedProcDef(n: PNode; ir: var PackedTree; c: var PackedEncoder; m: var
       # do not serialize the body of the proc, it's unnecessary since
       # n[0].sym.ast has the sem'checked variant of it which is what
       # everybody should use instead.
-      ir.nodes.add PackedNode(kind: nkEmpty, flags: {}, operand: 0,
-                              typeId: nilItemId, info: info)
+      ir.addNode(kind = nkEmpty, flags = {}, operand = 0,
+                 typeId = nilItemId, info = info)
   ir.patch patchPos
 
 proc toPackedNodeIgnoreProcDefs(n: PNode, encoder: var PackedEncoder; m: var PackedModule) =
@@ -563,6 +582,20 @@ proc toRodFile*(conf: ConfigRef; f: AbsoluteFile; ext = RodExt): AbsoluteFile =
   result = changeFileExt(completeGeneratedFilePath(conf,
     mangleModuleName(conf, f).AbsoluteFile), ext)
 
+const
+  BenchIC* = false
+
+when BenchIC:
+  var gloadBodies: MonoTime
+
+  template bench(x, body) =
+    let start = getMonoTime()
+    body
+    x = x + (getMonoTime() - start)
+
+else:
+  template bench(x, body) = body
+
 proc loadRodFile*(filename: AbsoluteFile; m: var PackedModule; config: ConfigRef;
                   ignoreConfig = false): RodFileError =
   var f = rodfiles.open(filename.string)
@@ -587,40 +620,48 @@ proc loadRodFile*(filename: AbsoluteFile; m: var PackedModule; config: ConfigRef
   loadTabSection stringsSection, m.strings
 
   loadSeqSection checkSumsSection, m.includes
-  if not includesIdentical(m, config):
+  if config.cmd != cmdM and not includesIdentical(m, config):
     f.err = includeFileChanged
 
   loadSeqSection depsSection, m.imports
 
-  loadTabSection numbersSection, m.numbers
+  bench gloadBodies:
 
-  loadSeqSection exportsSection, m.exports
-  loadSeqSection hiddenSection, m.hidden
-  loadSeqSection reexportsSection, m.reexports
+    loadTabSection numbersSection, m.numbers
 
-  loadSeqSection compilerProcsSection, m.compilerProcs
+    loadSeqSection exportsSection, m.exports
+    loadSeqSection hiddenSection, m.hidden
+    loadSeqSection reexportsSection, m.reexports
 
-  loadSeqSection trmacrosSection, m.trmacros
+    loadSeqSection compilerProcsSection, m.compilerProcs
 
-  loadSeqSection convertersSection, m.converters
-  loadSeqSection methodsSection, m.methods
-  loadSeqSection pureEnumsSection, m.pureEnums
+    loadSeqSection trmacrosSection, m.trmacros
 
-  loadSeqSection toReplaySection, m.toReplay.nodes
-  loadSeqSection topLevelSection, m.topLevel.nodes
-  loadSeqSection bodiesSection, m.bodies.nodes
-  loadSeqSection symsSection, m.syms
-  loadSeqSection typesSection, m.types
+    loadSeqSection convertersSection, m.converters
+    loadSeqSection methodsSection, m.methods
+    loadSeqSection pureEnumsSection, m.pureEnums
 
-  loadSeqSection typeInstCacheSection, m.typeInstCache
-  loadSeqSection procInstCacheSection, m.procInstCache
-  loadSeqSection attachedOpsSection, m.attachedOps
-  loadSeqSection methodsPerTypeSection, m.methodsPerType
-  loadSeqSection enumToStringProcsSection, m.enumToStringProcs
-  loadSeqSection typeInfoSection, m.emittedTypeInfo
+    loadTabSection toReplaySection, m.toReplay
+    loadTabSection topLevelSection, m.topLevel
 
-  f.loadSection backendFlagsSection
-  f.loadPrim m.backendFlags
+    loadTabSection bodiesSection, m.bodies
+    loadSeqSection symsSection, m.syms
+    loadSeqSection typesSection, m.types
+
+    loadSeqSection typeInstCacheSection, m.typeInstCache
+    loadSeqSection procInstCacheSection, m.procInstCache
+    loadSeqSection attachedOpsSection, m.attachedOps
+    loadSeqSection methodsPerGenericTypeSection, m.methodsPerGenericType
+    loadSeqSection enumToStringProcsSection, m.enumToStringProcs
+    loadSeqSection methodsPerTypeSection, m.methodsPerType
+    loadSeqSection dispatchersSection, m.dispatchers
+    loadSeqSection typeInfoSection, m.emittedTypeInfo
+
+    f.loadSection backendFlagsSection
+    f.loadPrim m.backendFlags
+
+    f.loadSection sideChannelSection
+  f.load m.man
 
   close(f)
   result = f.err
@@ -669,10 +710,10 @@ proc saveRodFile*(filename: AbsoluteFile; encoder: var PackedEncoder; m: var Pac
   storeSeqSection methodsSection, m.methods
   storeSeqSection pureEnumsSection, m.pureEnums
 
-  storeSeqSection toReplaySection, m.toReplay.nodes
-  storeSeqSection topLevelSection, m.topLevel.nodes
+  storeTabSection toReplaySection, m.toReplay
+  storeTabSection topLevelSection, m.topLevel
 
-  storeSeqSection bodiesSection, m.bodies.nodes
+  storeTabSection bodiesSection, m.bodies
   storeSeqSection symsSection, m.syms
 
   storeSeqSection typesSection, m.types
@@ -680,13 +721,18 @@ proc saveRodFile*(filename: AbsoluteFile; encoder: var PackedEncoder; m: var Pac
   storeSeqSection typeInstCacheSection, m.typeInstCache
   storeSeqSection procInstCacheSection, m.procInstCache
   storeSeqSection attachedOpsSection, m.attachedOps
-  storeSeqSection methodsPerTypeSection, m.methodsPerType
+  storeSeqSection methodsPerGenericTypeSection, m.methodsPerGenericType
   storeSeqSection enumToStringProcsSection, m.enumToStringProcs
+  storeSeqSection methodsPerTypeSection, m.methodsPerType
+  storeSeqSection dispatchersSection, m.dispatchers
   storeSeqSection typeInfoSection, m.emittedTypeInfo
 
   f.storeSection backendFlagsSection
   f.storePrim m.backendFlags
 
+  f.storeSection sideChannelSection
+  f.store m.man
+
   close(f)
   encoder.disable()
   if f.err != ok:
@@ -728,13 +774,29 @@ type
       # PackedItemId so that it works with reexported symbols too
       # ifaceHidden includes private symbols
 
-  PackedModuleGraph* = seq[LoadedModule] # indexed by FileIndex
+type
+  PackedModuleGraph* = object
+    pm*: seq[LoadedModule] # indexed by FileIndex
+    when BenchIC:
+      depAnalysis: MonoTime
+      loadBody: MonoTime
+      loadSym, loadType, loadBodies: MonoTime
+
+when BenchIC:
+  proc echoTimes*(m: PackedModuleGraph) =
+    echo "analysis: ", m.depAnalysis, " loadBody: ", m.loadBody, " loadSym: ",
+      m.loadSym, " loadType: ", m.loadType, " all bodies: ", gloadBodies
+
+template `[]`*(m: PackedModuleGraph; i: int): LoadedModule = m.pm[i]
+template len*(m: PackedModuleGraph): int = m.pm.len
 
 proc loadType(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; t: PackedItemId): PType
 proc loadSym(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; s: PackedItemId): PSym
 
 proc toFileIndexCached*(c: var PackedDecoder; g: PackedModuleGraph; thisModule: int; f: LitId): FileIndex =
-  if c.lastLit == f and c.lastModule == thisModule:
+  if f == LitId(0):
+    result = InvalidFileIdx
+  elif c.lastLit == f and c.lastModule == thisModule:
     result = c.lastFile
   else:
     result = toFileIndex(f, g[thisModule].fromDisk, c.config)
@@ -745,8 +807,9 @@ proc toFileIndexCached*(c: var PackedDecoder; g: PackedModuleGraph; thisModule:
 proc translateLineInfo(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
                        x: PackedLineInfo): TLineInfo =
   assert g[thisModule].status in {loaded, storing, stored}
-  result = TLineInfo(line: x.line, col: x.col,
-            fileIndex: toFileIndexCached(c, g, thisModule, x.file))
+  let (fileId, line, col) = unpack(g[thisModule].fromDisk.man, x)
+  result = TLineInfo(line: line.uint16, col: col.int16,
+            fileIndex: toFileIndexCached(c, g, thisModule, fileId))
 
 proc loadNodes*(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
                 tree: PackedTree; n: NodePos): PNode =
@@ -760,14 +823,14 @@ proc loadNodes*(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
   result.flags = n.flags
 
   case k
-  of nkEmpty, nkNilLit, nkType:
+  of nkNone, nkEmpty, nkNilLit, nkType:
     discard
   of nkIdent:
     result.ident = getIdent(c.cache, g[thisModule].fromDisk.strings[n.litId])
   of nkSym:
-    result.sym = loadSym(c, g, thisModule, PackedItemId(module: LitId(0), item: tree.nodes[n.int].operand))
-  of directIntLit:
-    result.intVal = tree.nodes[n.int].operand
+    result.sym = loadSym(c, g, thisModule, PackedItemId(module: LitId(0), item: tree[n].soperand))
+    if result.typ == nil and nfOpenSym notin result.flags:
+      result.typ = result.sym.typ
   of externIntLit:
     result.intVal = g[thisModule].fromDisk.numbers[n.litId]
   of nkStrLit..nkTripleStrLit:
@@ -776,10 +839,12 @@ proc loadNodes*(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
     result.floatVal = cast[BiggestFloat](g[thisModule].fromDisk.numbers[n.litId])
   of nkModuleRef:
     let (n1, n2) = sons2(tree, n)
-    assert n1.kind == nkInt32Lit
-    assert n2.kind == nkInt32Lit
+    assert n1.kind == nkNone
+    assert n2.kind == nkNone
     transitionNoneToSym(result)
-    result.sym = loadSym(c, g, thisModule, PackedItemId(module: n1.litId, item: tree.nodes[n2.int].operand))
+    result.sym = loadSym(c, g, thisModule, PackedItemId(module: n1.litId, item: tree[n2].soperand))
+    if result.typ == nil and nfOpenSym notin result.flags:
+      result.typ = result.sym.typ
   else:
     for n0 in sonsReadonly(tree, n):
       result.addAllowNil loadNodes(c, g, thisModule, tree, n0)
@@ -811,6 +876,7 @@ proc loadProcHeader(c: var PackedDecoder; g: var PackedModuleGraph; thisModule:
 
 proc loadProcBody(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
                   tree: PackedTree; n: NodePos): PNode =
+  result = nil
   var i = 0
   for n0 in sonsReadonly(tree, n):
     if i == bodyPos:
@@ -830,6 +896,7 @@ proc symHeaderFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
     options: s.options,
     position: if s.kind in {skForVar, skVar, skLet, skTemp}: 0 else: s.position,
     offset: if s.kind in routineKinds: defaultOffset else: s.offset,
+    disamb: s.disamb,
     name: getIdent(c.cache, g[si].fromDisk.strings[s.name])
   )
 
@@ -847,7 +914,7 @@ proc loadLib(c: var PackedDecoder; g: var PackedModuleGraph;
   if l.name.int == 0:
     result = nil
   else:
-    result = PLib(generated: l.generated, isOverriden: l.isOverriden,
+    result = PLib(generated: l.generated, isOverridden: l.isOverridden,
                   kind: l.kind, name: rope g[si].fromDisk.strings[l.name])
     loadAstBody(l, path)
 
@@ -872,12 +939,27 @@ proc symBodyFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
   if externalName != "":
     result.loc.r = rope externalName
   result.loc.flags = s.locFlags
+  result.instantiatedFrom = loadSym(c, g, si, s.instantiatedFrom)
+
+proc needsRecompile(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
+                    fileIdx: FileIndex; cachedModules: var seq[FileIndex]): bool
+proc loadToReplayNodes(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
+                       fileIdx: FileIndex; m: var LoadedModule)
 
 proc loadSym(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; s: PackedItemId): PSym =
   if s == nilItemId:
     result = nil
   else:
     let si = moduleIndex(c, g, thisModule, s)
+    if si >= g.len:
+      g.pm.setLen(si+1)
+
+    if g[si].status == undefined and c.config.cmd == cmdM:
+      var cachedModules: seq[FileIndex] = @[]
+      discard needsRecompile(g, c.config, c.cache, FileIndex(si), cachedModules)
+      for m in cachedModules:
+        loadToReplayNodes(g, c.config, c.cache, m, g[int m])
+
     assert g[si].status in {loaded, storing, stored}
     if not g[si].symsInit:
       g[si].symsInit = true
@@ -892,6 +974,7 @@ proc loadSym(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; s:
       else:
         result = g[si].module
         assert result != nil
+        g[si].syms[s.item] = result
 
     else:
       result = g[si].syms[s.item]
@@ -912,8 +995,10 @@ proc typeBodyFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
     for op, item in pairs t.attachedOps:
       result.attachedOps[op] = loadSym(c, g, si, item)
   result.typeInst = loadType(c, g, si, t.typeInst)
+  var sons = newSeq[PType]()
   for son in items t.types:
-    result.sons.add loadType(c, g, si, son)
+    sons.add loadType(c, g, si, son)
+  result.setSons(sons)
   loadAstBody(t, n)
   when false:
     for gen, id in items t.methods:
@@ -936,9 +1021,11 @@ proc loadType(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; t
       # store it here early on, so that recursions work properly:
       g[si].types[t.item] = result
       typeBodyFromPacked(c, g, g[si].fromDisk.types[t.item], si, t.item, result)
+      #assert result.itemId.item == t.item, $(result.itemId.item, t.item)
+      assert result.itemId.item > 0, $(result.itemId.item, t.item)
     else:
       result = g[si].types[t.item]
-    assert result.itemId.item > 0
+      assert result.itemId.item > 0, "2"
 
 proc setupLookupTables(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
                        fileIdx: FileIndex; m: var LoadedModule) =
@@ -988,30 +1075,37 @@ proc needsRecompile(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache
   # Does the file belong to the fileIdx need to be recompiled?
   let m = int(fileIdx)
   if m >= g.len:
-    g.setLen(m+1)
+    g.pm.setLen(m+1)
 
   case g[m].status
   of undefined:
     g[m].status = loading
     let fullpath = msgs.toFullPath(conf, fileIdx)
     let rod = toRodFile(conf, AbsoluteFile fullpath)
-    let err = loadRodFile(rod, g[m].fromDisk, conf)
+    let err = loadRodFile(rod, g[m].fromDisk, conf, ignoreConfig = conf.cmd == cmdM)
     if err == ok:
-      result = optForceFullMake in conf.globalOptions
-      # check its dependencies:
-      for dep in g[m].fromDisk.imports:
-        let fid = toFileIndex(dep, g[m].fromDisk, conf)
-        # Warning: we need to traverse the full graph, so
-        # do **not use break here**!
-        if needsRecompile(g, conf, cache, fid, cachedModules):
-          result = true
-
-      if not result:
+      if conf.cmd == cmdM:
         setupLookupTables(g, conf, cache, fileIdx, g[m])
         cachedModules.add fileIdx
         g[m].status = loaded
+        result = false
       else:
-        g[m] = LoadedModule(status: outdated, module: g[m].module)
+        result = optForceFullMake in conf.globalOptions
+        # check its dependencies:
+        let imp = g[m].fromDisk.imports
+        for dep in imp:
+          let fid = toFileIndex(dep, g[m].fromDisk, conf)
+          # Warning: we need to traverse the full graph, so
+          # do **not use break here**!
+          if needsRecompile(g, conf, cache, fid, cachedModules):
+            result = true
+
+        if not result:
+          setupLookupTables(g, conf, cache, fileIdx, g[m])
+          cachedModules.add fileIdx
+          g[m].status = loaded
+        else:
+          g.pm[m] = LoadedModule(status: outdated, module: g[m].module)
     else:
       loadError(err, rod, conf)
       g[m].status = outdated
@@ -1026,12 +1120,13 @@ proc needsRecompile(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache
 proc moduleFromRodFile*(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
                         fileIdx: FileIndex; cachedModules: var seq[FileIndex]): PSym =
   ## Returns 'nil' if the module needs to be recompiled.
-  if needsRecompile(g, conf, cache, fileIdx, cachedModules):
-    result = nil
-  else:
-    result = g[int fileIdx].module
-    assert result != nil
-    assert result.position == int(fileIdx)
+  bench g.depAnalysis:
+    if needsRecompile(g, conf, cache, fileIdx, cachedModules):
+      result = nil
+    else:
+      result = g[int fileIdx].module
+      assert result != nil
+      assert result.position == int(fileIdx)
   for m in cachedModules:
     loadToReplayNodes(g, conf, cache, m, g[int m])
 
@@ -1045,46 +1140,49 @@ template setupDecoder() {.dirty.} =
 
 proc loadProcBody*(config: ConfigRef, cache: IdentCache;
                    g: var PackedModuleGraph; s: PSym): PNode =
-  let mId = s.itemId.module
-  var decoder = PackedDecoder(
-    lastModule: int32(-1),
-    lastLit: LitId(0),
-    lastFile: FileIndex(-1),
-    config: config,
-    cache: cache)
-  let pos = g[mId].fromDisk.syms[s.itemId.item].ast
-  assert pos != emptyNodeId
-  result = loadProcBody(decoder, g, mId, g[mId].fromDisk.bodies, NodePos pos)
+  bench g.loadBody:
+    let mId = s.itemId.module
+    var decoder = PackedDecoder(
+      lastModule: int32(-1),
+      lastLit: LitId(0),
+      lastFile: FileIndex(-1),
+      config: config,
+      cache: cache)
+    let pos = g[mId].fromDisk.syms[s.itemId.item].ast
+    assert pos != emptyNodeId
+    result = loadProcBody(decoder, g, mId, g[mId].fromDisk.bodies, NodePos pos)
 
 proc loadTypeFromId*(config: ConfigRef, cache: IdentCache;
                      g: var PackedModuleGraph; module: int; id: PackedItemId): PType =
-  if id.item < g[module].types.len:
-    result = g[module].types[id.item]
-  else:
-    result = nil
-  if result == nil:
-    var decoder = PackedDecoder(
-      lastModule: int32(-1),
-      lastLit: LitId(0),
-      lastFile: FileIndex(-1),
-      config: config,
-      cache: cache)
-    result = loadType(decoder, g, module, id)
+  bench g.loadType:
+    if id.item < g[module].types.len:
+      result = g[module].types[id.item]
+    else:
+      result = nil
+    if result == nil:
+      var decoder = PackedDecoder(
+        lastModule: int32(-1),
+        lastLit: LitId(0),
+        lastFile: FileIndex(-1),
+        config: config,
+        cache: cache)
+      result = loadType(decoder, g, module, id)
 
 proc loadSymFromId*(config: ConfigRef, cache: IdentCache;
                     g: var PackedModuleGraph; module: int; id: PackedItemId): PSym =
-  if id.item < g[module].syms.len:
-    result = g[module].syms[id.item]
-  else:
-    result = nil
-  if result == nil:
-    var decoder = PackedDecoder(
-      lastModule: int32(-1),
-      lastLit: LitId(0),
-      lastFile: FileIndex(-1),
-      config: config,
-      cache: cache)
-    result = loadSym(decoder, g, module, id)
+  bench g.loadSym:
+    if id.item < g[module].syms.len:
+      result = g[module].syms[id.item]
+    else:
+      result = nil
+    if result == nil:
+      var decoder = PackedDecoder(
+        lastModule: int32(-1),
+        lastLit: LitId(0),
+        lastFile: FileIndex(-1),
+        config: config,
+        cache: cache)
+      result = loadSym(decoder, g, module, id)
 
 proc translateId*(id: PackedItemId; g: PackedModuleGraph; thisModule: int; config: ConfigRef): ItemId =
   if id.module == LitId(0):
@@ -1144,9 +1242,11 @@ proc initRodIter*(it: var RodIter; config: ConfigRef, cache: IdentCache;
   if it.i < it.values.len:
     result = loadSym(it.decoder, g, int(module), it.values[it.i])
     inc it.i
+  else:
+    result = nil
 
 proc initRodIterAllSyms*(it: var RodIter; config: ConfigRef, cache: IdentCache;
-                         g: var PackedModuleGraph; module: FileIndex, importHidden: bool): PSym =
+                         g: var PackedModuleGraph; module: FileIndex; importHidden: bool): PSym =
   it.decoder = PackedDecoder(
     lastModule: int32(-1),
     lastLit: LitId(0),
@@ -1161,11 +1261,15 @@ proc initRodIterAllSyms*(it: var RodIter; config: ConfigRef, cache: IdentCache;
   if it.i < it.values.len:
     result = loadSym(it.decoder, g, int(module), it.values[it.i])
     inc it.i
+  else:
+    result = nil
 
 proc nextRodIter*(it: var RodIter; g: var PackedModuleGraph): PSym =
   if it.i < it.values.len:
     result = loadSym(it.decoder, g, it.module, it.values[it.i])
     inc it.i
+  else:
+    result = nil
 
 iterator interfaceSymbols*(config: ConfigRef, cache: IdentCache;
                            g: var PackedModuleGraph; module: FileIndex;
@@ -1198,12 +1302,12 @@ proc searchForCompilerproc*(m: LoadedModule; name: string): int32 =
 # ------------------------- .rod file viewer ---------------------------------
 
 proc rodViewer*(rodfile: AbsoluteFile; config: ConfigRef, cache: IdentCache) =
-  var m: PackedModule
+  var m: PackedModule = PackedModule()
   let err = loadRodFile(rodfile, m, config, ignoreConfig=true)
   if err != ok:
     config.quitOrRaise "Error: could not load: " & $rodfile.string & " reason: " & $err
 
-  when true:
+  when false:
     echo "exports:"
     for ex in m.exports:
       echo "  ", m.strings[ex[0]], " local ID: ", ex[1]
@@ -1219,13 +1323,32 @@ proc rodViewer*(rodfile: AbsoluteFile; config: ConfigRef, cache: IdentCache) =
     for ex in m.hidden:
       echo "  ", m.strings[ex[0]], " local ID: ", ex[1]
 
-  echo "all symbols"
-  for i in 0..high(m.syms):
-    if m.syms[i].name != LitId(0):
-      echo "  ", m.strings[m.syms[i].name], " local ID: ", i, " kind ", m.syms[i].kind
-    else:
-      echo "  <anon symbol?> local ID: ", i, " kind ", m.syms[i].kind
+  when false:
+    echo "all symbols"
+    for i in 0..high(m.syms):
+      if m.syms[i].name != LitId(0):
+        echo "  ", m.strings[m.syms[i].name], " local ID: ", i, " kind ", m.syms[i].kind
+      else:
+        echo "  <anon symbol?> local ID: ", i, " kind ", m.syms[i].kind
 
   echo "symbols: ", m.syms.len, " types: ", m.types.len,
-    " top level nodes: ", m.topLevel.nodes.len, " other nodes: ", m.bodies.nodes.len,
+    " top level nodes: ", m.topLevel.len, " other nodes: ", m.bodies.len,
     " strings: ", m.strings.len, " numbers: ", m.numbers.len
+
+  echo "SIZES:"
+  echo "symbols: ", m.syms.len * sizeof(PackedSym), " types: ", m.types.len * sizeof(PackedType),
+    " top level nodes: ", m.topLevel.len * sizeof(PackedNode),
+    " other nodes: ", m.bodies.len * sizeof(PackedNode),
+    " strings: ", sizeOnDisc(m.strings)
+  when false:
+    var tt = 0
+    var fc = 0
+    for x in m.topLevel:
+      if x.kind == nkSym or x.typeId == nilItemId: inc tt
+      if x.flags == {}: inc fc
+    for x in m.bodies:
+      if x.kind == nkSym or x.typeId == nilItemId: inc tt
+      if x.flags == {}: inc fc
+    let total = float(m.topLevel.len + m.bodies.len)
+    echo "nodes with nil type: ", tt, " in % ", tt.float / total
+    echo "nodes with empty flags: ", fc.float / total

compiler/ic/integrity.nim

@@ -10,7 +10,7 @@
 ## Integrity checking for a set of .rod files.
 ## The set must cover a complete Nim project.
 
-import sets
+import std/sets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -72,15 +72,16 @@ proc checkForeignSym(c: var CheckedContext; symId: PackedItemId) =
     c.thisModule = oldThisModule
 
 proc checkNode(c: var CheckedContext; tree: PackedTree; n: NodePos) =
-  if tree[n.int].typeId != nilItemId:
-    checkType(c, tree[n.int].typeId)
+  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.nodes[n.int].operand)
+    checkLocalSym(c, tree[n].soperand)
   of directIntLit:
     discard
   of externIntLit, nkFloatLit..nkFloat128Lit:
@@ -89,9 +90,9 @@ proc checkNode(c: var CheckedContext; tree: PackedTree; n: NodePos) =
     assert c.g.packed[c.thisModule].fromDisk.strings.hasLitId n.litId
   of nkModuleRef:
     let (n1, n2) = sons2(tree, n)
-    assert n1.kind == nkInt32Lit
-    assert n2.kind == nkInt32Lit
-    checkForeignSym(c, PackedItemId(module: n1.litId, item: tree.nodes[n2.int].operand))
+    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)
@@ -134,13 +135,15 @@ proc checkModule(c: var CheckedContext; m: PackedModule) =
     typeInstCache*: seq[(PackedItemId, PackedItemId)]
     procInstCache*: seq[PackedInstantiation]
     attachedOps*: seq[(TTypeAttachedOp, PackedItemId, PackedItemId)]
-    methodsPerType*: seq[(PackedItemId, int, 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..high(g.packed):
+  for i in 0..<len(g.packed):
     # case statement here to enforce exhaustive checks.
     case g.packed[i].status
     of undefined:
@@ -150,4 +153,3 @@ proc checkIntegrity*(g: ModuleGraph) =
     of stored, storing, outdated, loaded:
       c.thisModule = int32 i
       checkModule(c, g.packed[i].fromDisk)
-

compiler/ic/navigator.nim

@@ -11,59 +11,70 @@
 ## IDE-like features. It uses the set of .rod files to accomplish
 ## its task. The set must cover a complete Nim project.
 
-import sets
+import std/sets
 
-from os import nil
+from std/os import nil
 from std/private/miscdollars import toLocation
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
 import ".." / [ast, modulegraphs, msgs, options]
+import ".." / nir / nirlineinfos
 import packed_ast, bitabs, ic
 
 type
+  UnpackedLineInfo = object
+    file: LitId
+    line, col: int
   NavContext = object
     g: ModuleGraph
     thisModule: int32
-    trackPos: PackedLineInfo
+    trackPos: UnpackedLineInfo
     alreadyEmitted: HashSet[string]
     outputSep: char # for easier testing, use short filenames and spaces instead of tabs.
 
-proc isTracked(current, trackPos: PackedLineInfo, tokenLen: int): bool =
-  if current.file == trackPos.file and current.line == trackPos.line:
+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 >= current.col and col < current.col+tokenLen:
-      return true
+    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(info, c.trackPos, c.g.packed[c.thisModule].fromDisk.strings[s.name].len)
+    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(info, c.trackPos, c.g.packed[s.module].fromDisk.strings[name].len)
+    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..high(tree.nodes):
-    case tree.nodes[i].kind
+  for i in 0..<len(tree):
+    let i = NodePos(i)
+    case tree[i].kind
     of nkSym:
-      let item = tree.nodes[i].operand
-      if searchLocalSym(c, c.g.packed[c.thisModule].fromDisk.syms[item], tree.nodes[i].info):
+      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:
-      if tree.nodes[i].info.line == c.trackPos.line and tree.nodes[i].info.file == c.trackPos.file:
-        let (n1, n2) = sons2(tree, NodePos i)
+      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.nodes[n2.int].operand)
+        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.nodes[i].info):
+        if searchForeignSym(c, itemId, tree[i].info):
           return itemId
     else: discard
   return EmptyItemId
@@ -73,36 +84,38 @@ proc isDecl(tree: PackedTree; n: NodePos): bool =
   const declarativeNodes = procDefs + {nkMacroDef, nkTemplateDef,
     nkLetSection, nkVarSection, nkUsingStmt, nkConstSection, nkTypeSection,
     nkIdentDefs, nkEnumTy, nkVarTuple}
-  result = n.int >= 0 and tree[n.int].kind in declarativeNodes
+  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[info.file]
+  var file = c.g.packed[c.thisModule].fromDisk.strings[fileId]
   if c.outputSep == ' ':
     file = os.extractFilename file
-  toLocation(m, file, info.line.int, info.col.int + ColOffset)
+  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..high(tree.nodes):
-    case tree.nodes[i].kind
+  for i in 0..<len(tree):
+    let i = NodePos(i)
+    case tree[i].kind
     of nkSym:
-      let item = tree.nodes[i].operand
+      let item = tree[i].soperand
       if sym.item == item and sym.module == c.thisModule:
-        usage(c, tree.nodes[i].info, isDecl(tree, parent(NodePos i)))
+        usage(c, tree[i].info, isDecl(tree, parent(i)))
     of nkModuleRef:
-      let (n1, n2) = sons2(tree, NodePos i)
-      assert n1.kind == nkInt32Lit
-      assert n2.kind == nkInt32Lit
-      let pId = PackedItemId(module: n1.litId, item: tree.nodes[n2.int].operand)
+      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.nodes[i].info, isDecl(tree, parent(NodePos i)))
+        usage(c, tree[i].info, isDecl(tree, parent(i)))
     else: discard
 
 proc searchForIncludeFile(g: ModuleGraph; fullPath: string): int =
-  for i in 0..high(g.packed):
+  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.
@@ -134,7 +147,7 @@ proc nav(g: ModuleGraph) =
   var c = NavContext(
     g: g,
     thisModule: int32 mid,
-    trackPos: PackedLineInfo(line: unpacked.line, col: unpacked.col, file: fileId),
+    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)
@@ -145,7 +158,7 @@ proc nav(g: ModuleGraph) =
     localError(g.config, unpacked, "no symbol at this position")
     return
 
-  for i in 0..high(g.packed):
+  for i in 0..<len(g.packed):
     # case statement here to enforce exhaustive checks.
     case g.packed[i].status
     of undefined:
@@ -162,7 +175,7 @@ proc navUsages*(g: ModuleGraph) = nav(g)
 proc navDefusages*(g: ModuleGraph) = nav(g)
 
 proc writeRodFiles*(g: ModuleGraph) =
-  for i in 0..high(g.packed):
+  for i in 0..<len(g.packed):
     case g.packed[i].status
     of undefined, loading, stored, loaded:
       discard "nothing to do"

compiler/ic/packed_ast.nim

@@ -12,10 +12,12 @@
 ## use this representation directly in all the transformations,
 ## it is superior.
 
-import hashes, tables, strtabs
-import bitabs
+import std/[hashes, tables, strtabs]
+import bitabs, rodfiles
 import ".." / [ast, options]
 
+import ".." / nir / nirlineinfos
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -31,21 +33,16 @@ type
     item*: int32         # same as the in-memory representation
 
 const
-  nilItemId* = PackedItemId(module: LitId(0), item: -1.int32)
+  nilItemId* = PackedItemId(module: LitId(0), item: 0.int32)
 
 const
   emptyNodeId* = NodeId(-1)
 
 type
-  PackedLineInfo* = object
-    line*: uint16
-    col*: int16
-    file*: LitId
-
   PackedLib* = object
     kind*: TLibKind
     generated*: bool
-    isOverriden*: bool
+    isOverridden*: bool
     name*: LitId
     path*: NodeId
 
@@ -63,13 +60,15 @@ type
     alignment*: int # for alignment
     options*: TOptions
     position*: int
-    offset*: int
+    offset*: int32
+    disamb*: int32
     externalName*: LitId # instead of TLoc
     locFlags*: TLocFlags
     annex*: PackedLib
     when hasFFI:
       cname*: LitId
     constraint*: NodeId
+    instantiatedFrom*: PackedItemId
 
   PackedType* = object
     kind*: TTypeKind
@@ -88,23 +87,35 @@ type
     typeInst*: PackedItemId
     nonUniqueId*: int32
 
-  PackedNode* = object     # 28 bytes
-    kind*: TNodeKind
-    flags*: TNodeFlags
-    operand*: int32  # for kind in {nkSym, nkSymDef}: SymId
-                     # for kind in {nkStrLit, nkIdent, nkNumberLit}: LitId
-                     # for kind in nkInt32Lit: direct value
-                     # for non-atom kinds: the number of nodes (for easy skipping)
-    typeId*: PackedItemId
+  PackedNode* = object     # 8 bytes
+    x: uint32
     info*: PackedLineInfo
 
   PackedTree* = object ## usually represents a full Nim module
-    nodes*: seq[PackedNode]
+    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.}
 
@@ -113,71 +124,35 @@ proc `==`*(a, b: NodePos): bool {.borrow.}
 proc `==`*(a, b: NodeId): bool {.borrow.}
 
 proc newTreeFrom*(old: PackedTree): PackedTree =
-  result.nodes = @[]
+  result = PackedTree(nodes: @[])
   when false: result.sh = old.sh
 
-when false:
-  proc declareSym*(tree: var PackedTree; kind: TSymKind;
-                  name: LitId; info: PackedLineInfo): SymId =
-    result = SymId(tree.sh.syms.len)
-    tree.sh.syms.add PackedSym(kind: kind, name: name, flags: {}, magic: mNone, info: info)
-
-  proc litIdFromName*(tree: PackedTree; name: string): LitId =
-    result = tree.sh.strings.getOrIncl(name)
-
-  proc add*(tree: var PackedTree; kind: TNodeKind; token: string; info: PackedLineInfo) =
-    tree.nodes.add PackedNode(kind: kind, info: info,
-                              operand: int32 getOrIncl(tree.sh.strings, token))
-
-  proc add*(tree: var PackedTree; kind: TNodeKind; info: PackedLineInfo) =
-    tree.nodes.add PackedNode(kind: kind, operand: 0, info: info)
-
-proc throwAwayLastNode*(tree: var PackedTree) =
-  tree.nodes.setLen(tree.nodes.len-1)
-
 proc addIdent*(tree: var PackedTree; s: LitId; info: PackedLineInfo) =
-  tree.nodes.add PackedNode(kind: nkIdent, operand: int32(s), info: info)
+  tree.nodes.add PackedNode(x: toX(nkIdent, uint32(s)), info: info)
 
 proc addSym*(tree: var PackedTree; s: int32; info: PackedLineInfo) =
-  tree.nodes.add PackedNode(kind: nkSym, operand: s, info: info)
-
-proc addModuleId*(tree: var PackedTree; s: ModuleId; info: PackedLineInfo) =
-  tree.nodes.add PackedNode(kind: nkInt32Lit, operand: int32(s), info: info)
+  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(kind: nkSym, operand: int32(s), info: info)
+  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
 
-proc copyTree*(dest: var PackedTree; tree: PackedTree; n: NodePos) =
-  # and this is why the IR is superior. We can copy subtrees
-  # via a linear scan.
-  let pos = n.int
-  let L = if isAtom(tree, pos): 1 else: tree.nodes[pos].operand
-  let d = dest.nodes.len
-  dest.nodes.setLen(d + L)
-  for i in 0..<L:
-    dest.nodes[d+i] = tree.nodes[pos+i]
-
-when false:
-  proc copySym*(dest: var PackedTree; tree: PackedTree; s: SymId): SymId =
-    result = SymId(dest.sh.syms.len)
-    assert int(s) < tree.sh.syms.len
-    let oldSym = tree.sh.syms[s.int]
-    dest.sh.syms.add oldSym
-
 type
   PatchPos = distinct int
 
-when false:
-  proc prepare*(tree: var PackedTree; kind: TNodeKind; info: PackedLineInfo): PatchPos =
-    result = PatchPos tree.nodes.len
-    tree.nodes.add PackedNode(kind: kind, operand: 0, info: info)
+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.nodes.add PackedNode(kind: kind, flags: flags, operand: 0, info: info,
-                            typeId: typeId)
+  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
@@ -185,26 +160,30 @@ proc prepare*(dest: var PackedTree; source: PackedTree; sourcePos: NodePos): Pat
 
 proc patch*(tree: var PackedTree; pos: PatchPos) =
   let pos = pos.int
-  assert tree.nodes[pos].kind > nkNilLit
+  let k = tree.nodes[pos].kind
+  assert k > nkNilLit
   let distance = int32(tree.nodes.len - pos)
-  tree.nodes[pos].operand = distance
+  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: int): lent PackedNode {.inline.} =
-  tree.nodes[i]
+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].operand > 0
-    inc pos, tree.nodes[pos].operand
+    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].operand
+  let last = pos + tree.nodes[pos].rawSpan
   inc pos
   while pos < last:
     yield NodePos pos
@@ -225,7 +204,7 @@ iterator isons*(dest: var PackedTree; tree: PackedTree;
 iterator sonsFrom1*(tree: PackedTree; n: NodePos): NodePos =
   var pos = n.int
   assert tree.nodes[pos].kind > nkNilLit
-  let last = pos + tree.nodes[pos].operand
+  let last = pos + tree.nodes[pos].rawSpan
   inc pos
   if pos < last:
     nextChild tree, pos
@@ -239,7 +218,7 @@ iterator sonsWithoutLast2*(tree: PackedTree; n: NodePos): NodePos =
     inc count
   var pos = n.int
   assert tree.nodes[pos].kind > nkNilLit
-  let last = pos + tree.nodes[pos].operand
+  let last = pos + tree.nodes[pos].rawSpan
   inc pos
   while pos < last and count > 2:
     yield NodePos pos
@@ -249,7 +228,7 @@ iterator sonsWithoutLast2*(tree: PackedTree; n: NodePos): NodePos =
 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].operand - 1 < n.int)):
+  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)
@@ -275,20 +254,32 @@ proc firstSon*(tree: PackedTree; n: NodePos): NodePos {.inline.} =
 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].operand
+  LitId tree.nodes[n.int].uoperand
 proc info*(tree: PackedTree; n: NodePos): PackedLineInfo {.inline.} =
   tree.nodes[n.int].info
 
-template typ*(n: NodePos): PackedItemId =
-  tree.nodes[n.int].typeId
-template flags*(n: NodePos): TNodeFlags =
-  tree.nodes[n.int].flags
+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
 
-template operand*(n: NodePos): int32 =
-  tree.nodes[n.int].operand
+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].operand
+  if isAtom(tree, pos): 1 else: tree.nodes[pos].rawSpan
 
 proc sons2*(tree: PackedTree; n: NodePos): (NodePos, NodePos) =
   assert(not isAtom(tree, n.int))
@@ -304,6 +295,7 @@ proc sons3*(tree: PackedTree; n: NodePos): (NodePos, NodePos, NodePos) =
   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):
@@ -317,64 +309,28 @@ when false:
 
 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].operand
+template litId*(n: NodePos): LitId = LitId tree.nodes[n.int].uoperand
 
-template symId*(n: NodePos): SymId = SymId tree.nodes[n.int].operand
+template symId*(n: NodePos): SymId = SymId tree.nodes[n.int].soperand
 
 proc firstSon*(n: NodePos): NodePos {.inline.} = NodePos(n.int+1)
 
-when false:
-  # xxx `nkStrLit` or `nkStrLit..nkTripleStrLit:` below?
-  proc strLit*(tree: PackedTree; n: NodePos): lent string =
-    assert n.kind == nkStrLit
-    result = tree.sh.strings[LitId tree.nodes[n.int].operand]
-
-  proc strVal*(tree: PackedTree; n: NodePos): string =
-    assert n.kind == nkStrLit
-    result = tree.sh.strings[LitId tree.nodes[n.int].operand]
-    #result = cookedStrLit(raw)
-
-  proc filenameVal*(tree: PackedTree; n: NodePos): string =
-    case n.kind
-    of nkStrLit:
-      result = strVal(tree, n)
-    of nkIdent:
-      result = tree.sh.strings[n.litId]
-    of nkSym:
-      result = tree.sh.strings[tree.sh.syms[int n.symId].name]
-    else:
-      result = ""
-
-  proc identAsStr*(tree: PackedTree; n: NodePos): lent string =
-    assert n.kind == nkIdent
-    result = tree.sh.strings[LitId tree.nodes[n.int].operand]
-
 const
   externIntLit* = {nkCharLit,
     nkIntLit,
     nkInt8Lit,
     nkInt16Lit,
+    nkInt32Lit,
     nkInt64Lit,
     nkUIntLit,
     nkUInt8Lit,
     nkUInt16Lit,
     nkUInt32Lit,
-    nkUInt64Lit} # nkInt32Lit is missing by design!
+    nkUInt64Lit}
 
-  externSIntLit* = {nkIntLit, nkInt8Lit, nkInt16Lit, nkInt64Lit}
+  externSIntLit* = {nkIntLit, nkInt8Lit, nkInt16Lit, nkInt32Lit, nkInt64Lit}
   externUIntLit* = {nkUIntLit, nkUInt8Lit, nkUInt16Lit, nkUInt32Lit, nkUInt64Lit}
-  directIntLit* = nkInt32Lit
-
-when false:
-  proc identIdImpl(tree: PackedTree; n: NodePos): LitId =
-    if n.kind == nkIdent:
-      result = n.litId
-    elif n.kind == nkSym:
-      result = tree.sh.syms[int n.symId].name
-    else:
-      result = LitId(0)
-
-  template identId*(n: NodePos): LitId = identIdImpl(tree, n)
+  directIntLit* = nkNone
 
 template copyInto*(dest, n, body) =
   let patchPos = prepare(dest, tree, n)
@@ -386,28 +342,8 @@ template copyIntoKind*(dest, kind, info, body) =
   body
   patch dest, patchPos
 
-when false:
-  proc hasPragma*(tree: PackedTree; n: NodePos; pragma: string): bool =
-    let litId = tree.sh.strings.getKeyId(pragma)
-    if litId == LitId(0):
-      return false
-    assert n.kind == nkPragma
-    for ch0 in sonsReadonly(tree, n):
-      if ch0.kind == nkExprColonExpr:
-        if ch0.firstSon.identId == litId:
-          return true
-      elif ch0.identId == litId:
-        return true
-
 proc getNodeId*(tree: PackedTree): NodeId {.inline.} = NodeId tree.nodes.len
 
-when false:
-  proc produceError*(dest: var PackedTree; tree: PackedTree; n: NodePos; msg: string) =
-    let patchPos = prepare(dest, nkError, n.info)
-    dest.add nkStrLit, msg, n.info
-    copyTree(dest, tree, n)
-    patch dest, patchPos
-
 iterator allNodes*(tree: PackedTree): NodePos =
   var p = 0
   while p < tree.len:
@@ -417,3 +353,13 @@ iterator allNodes*(tree: PackedTree): NodePos =
 
 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

compiler/ic/replayer.nim

@@ -14,7 +14,7 @@
 import ".." / [ast, modulegraphs, trees, extccomp, btrees,
   msgs, lineinfos, pathutils, options, cgmeth]
 
-import tables
+import std/tables
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -103,6 +103,17 @@ proc replayBackendProcs*(g: ModuleGraph; module: int) =
     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
@@ -127,12 +138,12 @@ proc replayGenericCacheInformation*(g: ModuleGraph; module: int) =
       module: module, sym: FullId(module: sym.module, packed: it.sym),
       concreteTypes: concreteTypes, inst: nil)
 
-  for it in mitems(g.packed[module].fromDisk.methodsPerType):
+  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.methodsPerType.mgetOrPut(key, @[]).add (col, LazySym(id: symId, sym: nil))
+    g.methodsPerGenericType.mgetOrPut(key, @[]).add (col, LazySym(id: symId, sym: nil))
 
   replayBackendProcs(g, module)
 

compiler/ic/rodfiles.nim

@@ -14,7 +14,7 @@
 ##     compiler works and less a storage format, you're probably looking for
 ##     the `ic` or `packed_ast` modules to understand the logical format.
 
-from typetraits import supportsCopyMem
+from std/typetraits import supportsCopyMem
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions]
@@ -92,11 +92,16 @@ type
     typeInstCacheSection
     procInstCacheSection
     attachedOpsSection
-    methodsPerTypeSection
+    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,
@@ -109,8 +114,8 @@ type
                        # better than exceptions.
 
 const
-  RodVersion = 1
-  cookie = [byte(0), byte('R'), byte('O'), byte('D'),
+  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.} =
@@ -206,16 +211,16 @@ proc loadSeq*[T](f: var RodFile; s: var seq[T]) =
     for i in 0..<lenPrefix:
       loadPrim(f, s[i])
 
-proc storeHeader*(f: var RodFile) =
+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) =
+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]
+  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:
@@ -231,13 +236,14 @@ proc storeSection*(f: var RodFile; s: RodSection) =
 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
+  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
 
@@ -245,5 +251,6 @@ 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

compiler/idents.nim

@@ -11,8 +11,8 @@
 # An identifier is a shared immutable string that can be compared by its
 # id. This module is essential for the compiler's performance.
 
-import
-  hashes, wordrecg
+import wordrecg
+import std/hashes
 
 when defined(nimPreviewSlimSystem):
   import std/assertions

compiler/importer.nim

@@ -10,10 +10,12 @@
 ## This module implements the symbol importing mechanism.
 
 import
-  intsets, ast, astalgo, msgs, options, idents, lookups,
-  semdata, modulepaths, sigmatch, lineinfos, sets,
-  modulegraphs, wordrecg, tables
-from strutils import `%`
+  ast, astalgo, msgs, options, idents, lookups,
+  semdata, modulepaths, sigmatch, lineinfos,
+  modulegraphs, wordrecg
+from std/strutils import `%`, startsWith
+from std/sequtils import addUnique
+import std/[sets, tables, intsets]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -113,6 +115,7 @@ proc rawImportSymbol(c: PContext, s, origin: PSym; importSet: var IntSet) =
 
 proc splitPragmas(c: PContext, n: PNode): (PNode, seq[TSpecialWord]) =
   template bail = globalError(c.config, n.info, "invalid pragma")
+  result = (nil, @[])
   if n.kind == nkPragmaExpr:
     if n.len == 2 and n[1].kind == nkPragma:
       result[0] = n[0]
@@ -141,7 +144,7 @@ proc importSymbol(c: PContext, n: PNode, fromMod: PSym; importSet: var IntSet) =
     # for an enumeration we have to add all identifiers
     if multiImport:
       # for a overloadable syms add all overloaded routines
-      var it: ModuleIter
+      var it: ModuleIter = default(ModuleIter)
       var e = initModuleIter(it, c.graph, fromMod, s.name)
       while e != nil:
         if e.name.id != s.name.id: internalError(c.config, n.info, "importSymbol: 3")
@@ -231,7 +234,7 @@ proc importForwarded(c: PContext, n: PNode, exceptSet: IntSet; fromMod: PSym; im
 proc importModuleAs(c: PContext; n: PNode, realModule: PSym, importHidden: bool): PSym =
   result = realModule
   template createModuleAliasImpl(ident): untyped =
-    createModuleAlias(realModule, nextSymId c.idgen, ident, n.info, c.config.options)
+    createModuleAlias(realModule, c.idgen, ident, n.info, c.config.options)
   if n.kind != nkImportAs: discard
   elif n.len != 2 or n[1].kind != nkIdent:
     localError(c.config, n.info, "module alias must be an identifier")
@@ -245,9 +248,11 @@ proc importModuleAs(c: PContext; n: PNode, realModule: PSym, importHidden: bool)
     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
 
 proc transformImportAs(c: PContext; n: PNode): tuple[node: PNode, importHidden: bool] =
-  var ret: typeof(result)
+  result = (nil, false)
+  var ret = default(typeof(result))
   proc processPragma(n2: PNode): PNode =
     let (result2, kws) = splitPragmas(c, n2)
     result = result2
@@ -298,11 +303,26 @@ 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")
-    suggestSym(c.graph, n.info, result, c.graph.usageSym, false)
+    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) =
+      if n.kind == nkImportAs:
+        suggestMod(n[0], realModule)
+      elif n.kind == nkInfix:
+        suggestMod(n[2], s)
+      else:
+        suggestSym(c.graph, n.info, s, c.graph.usageSym, false)
+    suggestMod(n, result)
     importStmtResult.add newSymNode(result, n.info)
     #newStrNode(toFullPath(c.config, f), n.info)
+  else:
+    result = nil
 
 proc afterImport(c: PContext, m: PSym) =
+  if isCachedModule(c.graph, m): return
   # fixes bug #17510, for re-exported symbols
   let realModuleId = c.importModuleMap[m.id]
   for s in allSyms(c.graph, m):
@@ -323,22 +343,24 @@ proc evalImport*(c: PContext, n: PNode): PNode =
   result = newNodeI(nkImportStmt, n.info)
   for i in 0..<n.len:
     let it = n[i]
-    if it.kind == nkInfix and it.len == 3 and it[2].kind == nkBracket:
-      let sep = it[0]
-      let dir = it[1]
-      var imp = newNodeI(nkInfix, it.info)
-      imp.add sep
-      imp.add dir
-      imp.add sep # dummy entry, replaced in the loop
-      for x in it[2]:
+    if it.kind in {nkInfix, nkPrefix} and it[^1].kind == nkBracket:
+      let lastPos = it.len - 1
+      var imp = copyNode(it)
+      newSons(imp, it.len)
+      for i in 0 ..< lastPos: imp[i] = it[i]
+      imp[lastPos] = imp[0] # dummy entry, replaced in the loop
+      for x in it[lastPos]:
         # transform `a/b/[c as d]` to `/a/b/c as d`
         if x.kind == nkInfix and x[0].ident.s == "as":
-          let impAs = copyTree(x)
-          imp[2] = x[1]
+          var impAs = copyNode(x)
+          newSons(impAs, 3)
+          impAs[0] = x[0]
+          imp[lastPos] = x[1]
           impAs[1] = imp
-          impMod(c, imp, result)
+          impAs[2] = x[2]
+          impMod(c, impAs, result)
         else:
-          imp[2] = x
+          imp[lastPos] = x
           impMod(c, imp, result)
     else:
       impMod(c, it, result)

compiler/injectdestructors.nim

@@ -14,11 +14,13 @@
 ## See doc/destructors.rst for a spec of the implemented rewrite rules
 
 import
-  intsets, strtabs, ast, astalgo, msgs, renderer, magicsys, types, idents,
-  strutils, options, lowerings, tables, modulegraphs,
+  ast, astalgo, msgs, renderer, magicsys, types, idents,
+  options, lowerings, modulegraphs,
   lineinfos, parampatterns, sighashes, liftdestructors, optimizer,
   varpartitions, aliasanalysis, dfa, wordrecg
 
+import std/[strtabs, tables, strutils, intsets]
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -36,6 +38,7 @@ type
     body: PNode
     otherUsage: TLineInfo
     inUncheckedAssignSection: int
+    inEnsureMove: int
 
   Scope = object # we do scope-based memory management.
     # a scope is comparable to an nkStmtListExpr like
@@ -66,11 +69,11 @@ 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}:
+    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): PNode =
-  let sym = newSym(skTemp, getIdent(c.graph.cache, ":tmpD"), nextSymId c.idgen, c.owner, info)
+  let sym = newSym(skTemp, getIdent(c.graph.cache, ":tmpD"), c.idgen, c.owner, info)
   sym.typ = typ
   s.vars.add(sym)
   result = newSymNode(sym)
@@ -78,11 +81,11 @@ proc getTemp(c: var Con; s: var Scope; typ: PType; info: TLineInfo): PNode =
 proc nestedScope(parent: var Scope; body: PNode): Scope =
   Scope(vars: @[], locals: @[], wasMoved: @[], final: @[], body: body, needsTry: false, parent: addr(parent))
 
-proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSingleUsedTemp}): PNode
+proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSingleUsedTemp}; inReturn = false): PNode
 
 type
   MoveOrCopyFlag = enum
-    IsDecl, IsExplicitSink
+    IsDecl, IsExplicitSink, IsReturn
 
 proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope; flags: set[MoveOrCopyFlag] = {}): PNode
 
@@ -160,7 +163,8 @@ proc isLastReadImpl(n: PNode; c: var Con; scope: var Scope): bool =
     result = false
 
 proc isLastRead(n: PNode; c: var Con; s: var Scope): bool =
-  if not hasDestructor(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
 
   let m = skipConvDfa(n)
   result = (m.kind == nkSym and sfSingleUsedTemp in m.sym.flags) or
@@ -184,11 +188,16 @@ proc isCursor(n: PNode): bool =
 template isUnpackedTuple(n: PNode): bool =
   ## we move out all elements of unpacked tuples,
   ## hence unpacked tuples themselves don't need to be destroyed
-  (n.kind == nkSym and n.sym.kind == skTemp and n.sym.typ.kind == tyTuple)
+  ## except it's already a cursor
+  (n.kind == nkSym and n.sym.kind == skTemp and
+   n.sym.typ.kind == tyTuple and sfCursor notin n.sym.flags)
 
-proc checkForErrorPragma(c: Con; t: PType; ri: PNode; opname: string) =
+proc checkForErrorPragma(c: Con; t: PType; ri: PNode; opname: string; inferredFromCopy = false) =
   var m = "'" & opname & "' is not available for type <" & typeToString(t) & ">"
-  if (opname == "=" or opname == "=copy") and ri != nil:
+  if inferredFromCopy:
+    m.add ", which is inferred from unavailable '=copy'"
+
+  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 '\''
@@ -203,15 +212,21 @@ proc checkForErrorPragma(c: Con; t: PType; ri: PNode; opname: string) =
       m.add " a 'sink' parameter"
   m.add "; routine: "
   m.add c.owner.name.s
+  #m.add "\n\n"
+  #m.add renderTree(c.body, {renderIds})
   localError(c.graph.config, ri.info, errGenerated, m)
 
 proc makePtrType(c: var Con, baseType: PType): PType =
-  result = newType(tyPtr, nextTypeId c.idgen, c.owner)
+  result = newType(tyPtr, c.idgen, c.owner)
   addSonSkipIntLit(result, baseType, c.idgen)
 
 proc genOp(c: var Con; op: PSym; dest: PNode): PNode =
-  let addrExp = newNodeIT(nkHiddenAddr, dest.info, makePtrType(c, dest.typ))
-  addrExp.add(dest)
+  var addrExp: PNode
+  if op.typ != nil and op.typ.signatureLen > 1 and op.typ.firstParamType.kind != tyVar:
+    addrExp = dest
+  else:
+    addrExp = newNodeIT(nkHiddenAddr, dest.info, makePtrType(c, dest.typ))
+    addrExp.add(dest)
   result = newTree(nkCall, newSymNode(op), addrExp)
 
 proc genOp(c: var Con; t: PType; kind: TTypeAttachedOp; dest, ri: PNode): PNode =
@@ -249,10 +264,20 @@ proc canBeMoved(c: Con; t: PType): bool {.inline.} =
 proc isNoInit(dest: PNode): bool {.inline.} =
   result = dest.kind == nkSym and sfNoInit in dest.sym.flags
 
-proc genSink(c: var Con; dest, ri: PNode; flags: set[MoveOrCopyFlag] = {}): PNode =
+proc deepAliases(dest, ri: PNode): bool =
+  case ri.kind
+  of nkCallKinds, nkStmtListExpr, nkBracket, nkTupleConstr, nkObjConstr,
+     nkCast, nkConv, nkObjUpConv, nkObjDownConv:
+    for r in ri:
+      if deepAliases(dest, r): return true
+    return false
+  else:
+    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 (isUnpackedTuple(dest) or IsDecl in flags or
       (isAnalysableFieldAccess(dest, c.owner) and isFirstWrite(dest, c)))) or
-      isNoInit(dest):
+      isNoInit(dest) or IsReturn in flags:
     # optimize sink call into a bitwise memcopy
     result = newTree(nkFastAsgn, dest, ri)
   else:
@@ -263,12 +288,19 @@ proc genSink(c: var Con; dest, ri: PNode; flags: set[MoveOrCopyFlag] = {}): PNod
     else:
       # the default is to use combination of `=destroy(dest)` and
       # and copyMem(dest, source). This is efficient.
-      result = newTree(nkStmtList, c.genDestroy(dest), newTree(nkFastAsgn, dest, ri))
+      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)
+        result = newTree(nkStmtList, newTree(nkFastAsgn, tmp, dest), newTree(nkFastAsgn, dest, ri),
+                         c.genDestroy(tmp))
+      else:
+        result = newTree(nkStmtList, c.genDestroy(dest), newTree(nkFastAsgn, dest, ri))
 
 proc isCriticalLink(dest: PNode): bool {.inline.} =
   #[
   Lins's idea that only "critical" links can introduce a cycle. This is
-  critical for the performance gurantees that we strive for: If you
+  critical for the performance guarantees that we strive for: If you
   traverse a data structure, no tracing will be performed at all.
   ORC is about this promise: The GC only touches the memory that the
   mutator touches too.
@@ -287,14 +319,14 @@ proc isCriticalLink(dest: PNode): bool {.inline.} =
 
 proc finishCopy(c: var Con; result, dest: PNode; isFromSink: bool) =
   if c.graph.config.selectedGC == gcOrc:
-    let t = dest.typ.skipTypes({tyGenericInst, tyAlias, tySink, tyDistinct})
-    if cyclicType(t):
+    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 == gcOrc:
     let t = dest.typ.skipTypes({tyGenericInst, tyAlias, tySink, tyDistinct})
-    if cyclicType(t):
+    if cyclicType(c.graph, t):
       if t.kind == tyRef:
         result.add callCodegenProc(c.graph, "nimMarkCyclic", dest.info, dest)
       else:
@@ -308,6 +340,9 @@ proc genCopyNoCheck(c: var Con; dest, ri: PNode; a: TTypeAttachedOp): PNode =
   assert ri.typ != nil
 
 proc genCopy(c: var Con; dest, ri: PNode; flags: set[MoveOrCopyFlag]): PNode =
+  if c.inEnsureMove > 0:
+    localError(c.graph.config, ri.info, errFailedMove, "cannot move '" & $ri &
+                                                      "', which introduces an implicit copy")
   let t = dest.typ
   if tfHasOwned in t.flags and ri.kind != nkNilLit:
     # try to improve the error message here:
@@ -336,7 +371,7 @@ proc genDiscriminantAsgn(c: var Con; s: var Scope; n: PNode): PNode =
 
   if hasDestructor(c, objType):
     if getAttachedOp(c.graph, objType, attachedDestructor) != nil and
-        sfOverriden in getAttachedOp(c.graph, objType, attachedDestructor).flags:
+        sfOverridden in getAttachedOp(c.graph, objType, attachedDestructor).flags:
       localError(c.graph.config, n.info, errGenerated, """Assignment to discriminant for objects with user defined destructor is not supported, object must have default destructor.
 It is best to factor out piece of object that needs custom destructor into separate object or not use discriminator assignment""")
       result.add newTree(nkFastAsgn, le, tmp)
@@ -364,7 +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 & ")")
@@ -376,13 +411,16 @@ proc genDefaultCall(t: PType; c: Con; info: TLineInfo): PNode =
 
 proc destructiveMoveVar(n: PNode; c: var Con; s: var Scope): PNode =
   # generate: (let tmp = v; reset(v); tmp)
-  if not hasDestructor(c, n.typ):
-    assert n.kind != nkSym or not hasDestructor(c, n.sym.typ)
+  if (not hasDestructor(c, n.typ)) and c.inEnsureMove == 0:
+    assert n.kind != nkSym or not hasDestructor(c, n.sym.typ) or
+          (n.typ.kind == tyPtr and n.sym.typ.kind == tyRef)
+      # bug #23505; transformed by `transf`: addr (deref ref) -> ptr
+      # we know it's really a pointer; so here we assign it directly
     result = copyTree(n)
   else:
     result = newNodeIT(nkStmtListExpr, n.info, n.typ)
 
-    var temp = newSym(skLet, getIdent(c.graph.cache, "blitTmp"), nextSymId c.idgen, c.owner, n.info)
+    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)
     let tempAsNode = newSymNode(temp)
@@ -395,7 +433,8 @@ proc destructiveMoveVar(n: PNode; c: var Con; s: var Scope): PNode =
 
     result.add v
     let nn = skipConv(n)
-    c.genMarkCyclic(result, nn)
+    if hasDestructor(c, n.typ):
+      c.genMarkCyclic(result, nn)
     let wasMovedCall = c.genWasMoved(nn)
     result.add wasMovedCall
     result.add tempAsNode
@@ -403,24 +442,50 @@ proc destructiveMoveVar(n: PNode; c: var Con; s: var Scope): PNode =
 proc isCapturedVar(n: PNode): bool =
   let root = getRoot(n)
   if root != nil: result = root.name.s[0] == ':'
+  else: result = false
 
 proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
   result = newNodeIT(nkStmtListExpr, n.info, n.typ)
-  let tmp = c.getTemp(s, n.typ, n.info)
-  if hasDestructor(c, n.typ):
-    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 n.typ.skipTypes(abstractInst).kind != tyRef and c.inSpawn == 0:
+  let nTyp = n.typ.skipTypes(tyUserTypeClasses)
+  let tmp = c.getTemp(s, nTyp, n.info)
+  if hasDestructor(c, nTyp):
+    let typ = nTyp.skipTypes({tyGenericInst, tyAlias, tySink})
+    let 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}:
-      assert(not containsManagedMemory(n.typ))
-    if n.typ.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
+    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")
     result.add newTree(nkAsgn, tmp, p(n, c, s, normal))
   # Since we know somebody will take over the produced copy, there is
@@ -429,7 +494,7 @@ proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
 
 proc isDangerousSeq(t: PType): bool {.inline.} =
   let t = t.skipTypes(abstractInst)
-  result = t.kind == tySequence and tfHasOwned notin t[0].flags
+  result = t.kind == tySequence and tfHasOwned notin t.elementType.flags
 
 proc containsConstSeq(n: PNode): bool =
   if n.kind == nkBracket and n.len > 0 and n.typ != nil and isDangerousSeq(n.typ):
@@ -454,14 +519,14 @@ proc ensureDestruction(arg, orig: PNode; c: var Con; s: var Scope): PNode =
     # 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)
-    result.add c.genSink(tmp, arg, {IsDecl})
+    result.add c.genSink(s, tmp, arg, {IsDecl})
     result.add tmp
     s.final.add c.genDestroy(tmp)
   else:
     result = arg
 
 proc cycleCheck(n: PNode; c: var Con) =
-  if c.graph.config.selectedGC != gcArc: return
+  if c.graph.config.selectedGC notin {gcArc, gcAtomicArc}: return
   var value = n[1]
   if value.kind == nkClosure:
     value = value[1]
@@ -534,7 +599,9 @@ template processScopeExpr(c: var Con; s: var Scope; ret: PNode, processCall: unt
   # tricky because you would have to intercept moveOrCopy at a certain point
   let tmp = c.getTemp(s.parent[], ret.typ, ret.info)
   tmp.sym.flags = tmpFlags
-  let cpy = if hasDestructor(c, ret.typ):
+  let cpy = if hasDestructor(c, ret.typ) and
+                ret.typ.kind notin {tyOpenArray, tyVarargs}:
+                # bug #23247 we don't own the data, so it's harmful to destroy it
               s.parent[].final.add c.genDestroy(tmp)
               moveOrCopy(tmp, ret, c, s, {IsDecl})
             else:
@@ -662,7 +729,27 @@ template handleNestedTempl(n, processCall: untyped, willProduceStmt = false,
   of nkWhen: # This should be a "when nimvm" node.
     result = copyTree(n)
     result[1][0] = processCall(n[1][0], s)
-  else: assert(false)
+
+  of nkPragmaBlock:
+    var inUncheckedAssignSection = 0
+    let pragmaList = n[0]
+    for pi in pragmaList:
+      if whichPragma(pi) == wCast:
+        case whichPragma(pi[1])
+        of wUncheckedAssign:
+          inUncheckedAssignSection = 1
+        else:
+          discard
+    result = shallowCopy(n)
+    inc c.inUncheckedAssignSection, inUncheckedAssignSection
+    for i in 0 ..< n.len-1:
+      result[i] = p(n[i], c, s, normal)
+    result[^1] = maybeVoid(n[^1], s)
+    dec c.inUncheckedAssignSection, inUncheckedAssignSection
+
+  else:
+    result = nil
+    assert(false)
 
 proc pRaiseStmt(n: PNode, c: var Con; s: var Scope): PNode =
   if optOwnedRefs in c.graph.config.globalOptions and n[0].kind != nkEmpty:
@@ -689,9 +776,21 @@ proc pRaiseStmt(n: PNode, c: var Con; s: var Scope): PNode =
       result.add copyNode(n[0])
   s.needsTry = true
 
-proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSingleUsedTemp}): PNode =
+template isCustomDestructor(c: Con, t: PType): bool =
+  hasDestructor(c, t) and
+          getAttachedOp(c.graph, t, attachedDestructor) != nil and
+          sfOverridden in getAttachedOp(c.graph, t, attachedDestructor).flags
+
+proc hasCustomDestructor(c: Con, t: PType): bool =
+  result = isCustomDestructor(c, t)
+  var obj = t
+  while obj.baseClass != nil:
+    obj = skipTypes(obj.baseClass, abstractPtrs)
+    result = result or isCustomDestructor(c, obj)
+
+proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSingleUsedTemp}; inReturn = false): PNode =
   if n.kind in {nkStmtList, nkStmtListExpr, nkBlockStmt, nkBlockExpr, nkIfStmt,
-                nkIfExpr, nkCaseStmt, nkWhen, nkWhileStmt, nkParForStmt, nkTryStmt}:
+                nkIfExpr, nkCaseStmt, nkWhen, nkWhileStmt, nkParForStmt, nkTryStmt, nkPragmaBlock}:
     template process(child, s): untyped = p(child, c, s, mode)
     handleNestedTempl(n, process, tmpFlags = tmpFlags)
   elif mode == sinkArg:
@@ -702,7 +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
@@ -771,9 +878,15 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
             result[i][1] = p(n[i][1], c, s, m)
         else:
           result[i] = p(n[i], c, s, m)
-      if mode == normal and isRefConstr:
+      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
@@ -781,7 +894,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
         c.inSpawn.dec
 
       let parameters = n[0].typ
-      let L = if parameters != nil: parameters.len else: 0
+      let L = if parameters != nil: parameters.signatureLen else: 0
 
       when false:
         var isDangerous = false
@@ -804,14 +917,17 @@ 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, gcOrc}:
+        if c.graph.config.selectedGC in {gcHooks, gcArc, gcAtomicArc, gcOrc}:
           let destroyOld = c.genDestroy(result[1])
           result = newTree(nkStmtList, destroyOld, result)
       else:
         result[0] = p(n[0], c, s, normal)
       if canRaise(n[0]): s.needsTry = true
       if mode == normal:
-        result = ensureDestruction(result, n, c, s)
+        if result.typ != nil and result.typ.kind notin {tyOpenArray, tyVarargs}:
+          # Returns of openarray types shouldn't be destroyed
+          # bug #19435; # bug #23247
+          result = ensureDestruction(result, n, c, s)
     of nkDiscardStmt: # Small optimization
       result = shallowCopy(n)
       if n[0].kind != nkEmpty:
@@ -859,7 +975,9 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
         if n[0].kind in {nkDotExpr, nkCheckedFieldExpr}:
           cycleCheck(n, c)
         assert n[1].kind notin {nkAsgn, nkFastAsgn, nkSinkAsgn}
-        let flags = if n.kind == nkSinkAsgn: {IsExplicitSink} else: {}
+        var flags = if n.kind == nkSinkAsgn: {IsExplicitSink} else: {}
+        if inReturn:
+          flags.incl(IsReturn)
         result = moveOrCopy(p(n[0], c, s, mode), n[1], c, s, flags)
       elif isDiscriminantField(n[0]):
         result = c.genDiscriminantAsgn(s, n)
@@ -887,25 +1005,6 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
         if mode == normal:
           result = ensureDestruction(result, n, c, s)
 
-    of nkPragmaBlock:
-      var inUncheckedAssignSection = 0
-      let pragmaList = n[0]
-      for pi in pragmaList:
-        if whichPragma(pi) == wCast:
-          case whichPragma(pi[1])
-          of wUncheckedAssign:
-            inUncheckedAssignSection = 1
-          else:
-            discard
-      result = shallowCopy(n)
-      inc c.inUncheckedAssignSection, inUncheckedAssignSection
-      for i in 0 ..< n.len:
-        result[i] = p(n[i], c, s, normal)
-      dec c.inUncheckedAssignSection, inUncheckedAssignSection
-      if n.typ != nil and hasDestructor(c, n.typ):
-        if mode == normal:
-          result = ensureDestruction(result, n, c, s)
-
     of nkHiddenSubConv, nkHiddenStdConv, nkConv:
       # we have an "ownership invariance" for all constructors C(x).
       # See the comment for nkBracket construction. If the caller wants
@@ -962,7 +1061,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
     of nkReturnStmt:
       result = shallowCopy(n)
       for i in 0..<n.len:
-        result[i] = p(n[i], c, s, mode)
+        result[i] = p(n[i], c, s, mode, inReturn=true)
       s.needsTry = true
     of nkCast:
       result = shallowCopy(n)
@@ -976,11 +1075,12 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
     of nkGotoState, nkState, nkAsmStmt:
       result = n
     else:
+      result = nil
       internalError(c.graph.config, n.info, "cannot inject destructors to node kind: " & $n.kind)
 
 proc sameLocation*(a, b: PNode): bool =
   proc sameConstant(a, b: PNode): bool =
-    a.kind in nkLiterals and a.intVal == b.intVal
+    a.kind in nkLiterals and b.kind in nkLiterals and a.intVal == b.intVal
 
   const nkEndPoint = {nkSym, nkDotExpr, nkCheckedFieldExpr, nkBracketExpr}
   if a.kind in nkEndPoint and b.kind in nkEndPoint:
@@ -1004,9 +1104,9 @@ proc sameLocation*(a, b: PNode): bool =
     of nkHiddenStdConv, nkHiddenSubConv: sameLocation(a[1], b)
     else: false
 
-proc genFieldAccessSideEffects(c: var Con; dest, ri: PNode; flags: set[MoveOrCopyFlag] = {}): PNode =
+proc genFieldAccessSideEffects(c: var Con; s: var Scope; dest, ri: PNode; flags: set[MoveOrCopyFlag] = {}): PNode =
   # with side effects
-  var temp = newSym(skLet, getIdent(c.graph.cache, "bracketTmp"), nextSymId c.idgen, c.owner, ri[1].info)
+  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)
@@ -1021,14 +1121,22 @@ proc genFieldAccessSideEffects(c: var Con; dest, ri: PNode; flags: set[MoveOrCop
   newAccess.add ri[0]
   newAccess.add tempAsNode
 
-  var snk = c.genSink(dest, newAccess, flags)
+  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
+  var isEnsureMove = 0
+  if ri.kind in nkCallKinds and ri[0].kind == nkSym and ri[0].sym.magic == mEnsureMove:
+    ri = ri[1]
+    isEnsureMove = 1
   if sameLocation(dest, ri):
     # rule (self-assignment-removal):
     result = newNodeI(nkEmpty, dest.info)
-  elif isCursor(dest):
+  elif isCursor(dest) or dest.typ.kind in {tyOpenArray, tyVarargs}:
+    # hoisted openArray parameters might end up here
+    # openArray types don't have a lifted assignment operation (it's empty)
+    # bug #22132
     case ri.kind:
     of nkStmtListExpr, nkBlockExpr, nkIfExpr, nkCaseStmt, nkTryStmt:
       template process(child, s): untyped = moveOrCopy(dest, child, c, s, flags)
@@ -1037,53 +1145,61 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
     else:
       result = newTree(nkFastAsgn, dest, p(ri, c, s, normal))
   else:
-    case ri.kind
+    let ri2 = if ri.kind == nkWhen: ri[1][0] else: ri
+    case ri2.kind
     of nkCallKinds:
-      result = c.genSink(dest, p(ri, c, s, consumed), flags)
+      result = c.genSink(s, dest, p(ri, c, s, consumed), flags)
     of nkBracketExpr:
       if isUnpackedTuple(ri[0]):
         # unpacking of tuple: take over the elements
-        result = c.genSink(dest, p(ri, c, s, consumed), flags)
+        result = c.genSink(s, dest, p(ri, c, s, consumed), flags)
       elif isAnalysableFieldAccess(ri, c.owner) and isLastRead(ri, c, s):
         if aliases(dest, ri) == no:
           # Rule 3: `=sink`(x, z); wasMoved(z)
           if isAtom(ri[1]):
-            var snk = c.genSink(dest, ri, flags)
+            var snk = c.genSink(s, dest, ri, flags)
             result = newTree(nkStmtList, snk, c.genWasMoved(ri))
           else:
-            result = genFieldAccessSideEffects(c, dest, ri, flags)
+            result = genFieldAccessSideEffects(c, s, dest, ri, flags)
         else:
-          result = c.genSink(dest, destructiveMoveVar(ri, c, s), flags)
+          result = c.genSink(s, dest, destructiveMoveVar(ri, c, s), flags)
       else:
+        inc c.inEnsureMove, isEnsureMove
         result = c.genCopy(dest, ri, flags)
+        dec c.inEnsureMove, isEnsureMove
         result.add p(ri, c, s, consumed)
         c.finishCopy(result, dest, isFromSink = false)
     of nkBracket:
       # array constructor
       if ri.len > 0 and isDangerousSeq(ri.typ):
+        inc c.inEnsureMove, isEnsureMove
         result = c.genCopy(dest, ri, flags)
+        dec c.inEnsureMove, isEnsureMove
         result.add p(ri, c, s, consumed)
         c.finishCopy(result, dest, isFromSink = false)
       else:
-        result = c.genSink(dest, p(ri, c, s, consumed), flags)
+        result = c.genSink(s, dest, p(ri, c, s, consumed), flags)
     of nkObjConstr, nkTupleConstr, nkClosure, nkCharLit..nkNilLit:
-      result = c.genSink(dest, p(ri, c, s, consumed), flags)
+      result = c.genSink(s, dest, p(ri, c, s, consumed), flags)
     of nkSym:
       if isSinkParam(ri.sym) and isLastRead(ri, c, s):
         # Rule 3: `=sink`(x, z); wasMoved(z)
-        let snk = c.genSink(dest, ri, flags)
+        let snk = c.genSink(s, dest, ri, flags)
         result = newTree(nkStmtList, snk, c.genWasMoved(ri))
-      elif ri.sym.kind != skParam and ri.sym.owner == c.owner and
-          isLastRead(ri, c, s) and canBeMoved(c, dest.typ) and not isCursor(ri):
+      elif ri.sym.kind != skParam and
+          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(dest, ri, flags)
+        let snk = c.genSink(s, dest, ri, flags)
         result = newTree(nkStmtList, snk, c.genWasMoved(ri))
       else:
+        inc c.inEnsureMove, isEnsureMove
         result = c.genCopy(dest, ri, flags)
+        dec c.inEnsureMove, isEnsureMove
         result.add p(ri, c, s, consumed)
         c.finishCopy(result, dest, isFromSink = false)
     of nkHiddenSubConv, nkHiddenStdConv, nkConv, nkObjDownConv, nkObjUpConv, nkCast:
-      result = c.genSink(dest, p(ri, c, s, sinkArg), flags)
+      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
@@ -1094,10 +1210,12 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
       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(dest, ri, flags)
+        let snk = c.genSink(s, dest, ri, flags)
         result = newTree(nkStmtList, snk, c.genWasMoved(ri))
       else:
+        inc c.inEnsureMove, isEnsureMove
         result = c.genCopy(dest, ri, flags)
+        dec c.inEnsureMove, isEnsureMove
         result.add p(ri, c, s, consumed)
         c.finishCopy(result, dest, isFromSink = false)
 

compiler/installer.ini

@@ -6,11 +6,11 @@ Name: "Nim"
 Version: "$version"
 Platforms: """
   windows: i386;amd64
-  linux: i386;hppa;ia64;alpha;amd64;powerpc64;arm;sparc;sparc64;m68k;mips;mipsel;mips64;mips64el;powerpc;powerpc64el;arm64;riscv32;riscv64
+  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
-  netbsd: i386;amd64
+  netbsd: i386;amd64;arm64
   openbsd: i386;amd64;arm;arm64
   dragonfly: i386;amd64
   crossos: amd64
@@ -71,6 +71,7 @@ Files: "testament"
 Files: "nimsuggest"
 Files: "nimsuggest/tests/*.nim"
 Files: "changelogs/*.md"
+Files: "ci/funs.sh"
 
 [Lib]
 Files: "lib"
@@ -78,6 +79,7 @@ Files: "lib"
 [Other]
 Files: "examples"
 Files: "dist/nimble"
+Files: "dist/checksums"
 
 Files: "tests"
 
@@ -91,6 +93,7 @@ Files: "bin/nimgrab.exe"
 Files: "bin/nimpretty.exe"
 Files: "bin/testament.exe"
 Files: "bin/nim-gdb.bat"
+Files: "bin/atlas.exe"
 
 Files: "koch.exe"
 Files: "finish.exe"
@@ -144,4 +147,4 @@ licenses: "bin/nim,MIT;lib/*,MIT;"
 
 [nimble]
 pkgName: "nim"
-pkgFiles: "compiler/*;doc/basicopt.txt;doc/advopt.txt;doc/nimdoc.css"
+pkgFiles: "compiler/*;doc/basicopt.txt;doc/advopt.txt;doc/nimdoc.css;doc/nimdoc.cls"

compiler/int128.nim

@@ -3,7 +3,7 @@
 ## hold all from `low(BiggestInt)` to `high(BiggestUInt)`, This
 ## type is for that purpose.
 
-from math import trunc
+from std/math import trunc
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -34,6 +34,7 @@ proc `$`*(a: Int128): string
 
 proc toInt128*[T: SomeInteger | bool](arg: T): Int128 =
   {.noSideEffect.}:
+    result = Zero
     when T is bool: result.sdata(0) = int32(arg)
     elif T is SomeUnsignedInt:
       when sizeof(arg) <= 4:
@@ -171,6 +172,7 @@ proc addToHex*(result: var string; arg: Int128) =
     i -= 1
 
 proc toHex*(arg: Int128): string =
+  result = ""
   result.addToHex(arg)
 
 proc inc*(a: var Int128, y: uint32 = 1) =
@@ -207,30 +209,35 @@ proc `==`*(a, b: Int128): bool =
   return true
 
 proc bitnot*(a: Int128): Int128 =
+  result = Zero
   result.udata[0] = not a.udata[0]
   result.udata[1] = not a.udata[1]
   result.udata[2] = not a.udata[2]
   result.udata[3] = not a.udata[3]
 
 proc bitand*(a, b: Int128): Int128 =
+  result = Zero
   result.udata[0] = a.udata[0] and b.udata[0]
   result.udata[1] = a.udata[1] and b.udata[1]
   result.udata[2] = a.udata[2] and b.udata[2]
   result.udata[3] = a.udata[3] and b.udata[3]
 
 proc bitor*(a, b: Int128): Int128 =
+  result = Zero
   result.udata[0] = a.udata[0] or b.udata[0]
   result.udata[1] = a.udata[1] or b.udata[1]
   result.udata[2] = a.udata[2] or b.udata[2]
   result.udata[3] = a.udata[3] or b.udata[3]
 
 proc bitxor*(a, b: Int128): Int128 =
+  result = Zero
   result.udata[0] = a.udata[0] xor b.udata[0]
   result.udata[1] = a.udata[1] xor b.udata[1]
   result.udata[2] = a.udata[2] xor b.udata[2]
   result.udata[3] = a.udata[3] xor b.udata[3]
 
 proc `shr`*(a: Int128, b: int): Int128 =
+  result = Zero
   let b = b and 127
   if b < 32:
     result.sdata(3) = a.sdata(3) shr b
@@ -257,6 +264,7 @@ proc `shr`*(a: Int128, b: int): Int128 =
     result.sdata(0) = a.sdata(3) shr (b and 31)
 
 proc `shl`*(a: Int128, b: int): Int128 =
+  result = Zero
   let b = b and 127
   if b < 32:
     result.udata[0] = a.udata[0] shl b
@@ -280,6 +288,7 @@ proc `shl`*(a: Int128, b: int): Int128 =
     result.udata[3] = a.udata[0] shl (b and 31)
 
 proc `+`*(a, b: Int128): Int128 =
+  result = Zero
   let tmp0 = uint64(a.udata[0]) + uint64(b.udata[0])
   result.udata[0] = cast[uint32](tmp0)
   let tmp1 = uint64(a.udata[1]) + uint64(b.udata[1]) + (tmp0 shr 32)
@@ -312,6 +321,7 @@ proc abs(a: int32): int =
   if a < 0: -a else: a
 
 proc `*`(a: Int128, b: uint32): Int128 =
+  result = Zero
   let tmp0 = uint64(a.udata[0]) * uint64(b)
   let tmp1 = uint64(a.udata[1]) * uint64(b)
   let tmp2 = uint64(a.udata[2]) * uint64(b)
@@ -330,10 +340,11 @@ proc `*`*(a: Int128, b: int32): Int128 =
   if b < 0:
     result = -result
 
-proc `*=`*(a: var Int128, b: int32): Int128 =
-  result = result * b
+proc `*=`(a: var Int128, b: int32) =
+  a = a * b
 
 proc makeInt128(high, low: uint64): Int128 =
+  result = Zero
   result.udata[0] = cast[uint32](low)
   result.udata[1] = cast[uint32](low shr 32)
   result.udata[2] = cast[uint32](high)
@@ -357,9 +368,10 @@ proc `*`*(lhs, rhs: Int128): Int128 =
 proc `*=`*(a: var Int128, b: Int128) =
   a = a * b
 
-import bitops
+import std/bitops
 
 proc fastLog2*(a: Int128): int =
+  result = 0
   if a.udata[3] != 0:
     return 96 + fastLog2(a.udata[3])
   if a.udata[2] != 0:
@@ -371,6 +383,8 @@ proc fastLog2*(a: Int128): int =
 
 proc divMod*(dividend, divisor: Int128): tuple[quotient, remainder: Int128] =
   assert(divisor != Zero)
+  result = (Zero, Zero)
+
   let isNegativeA = isNegative(dividend)
   let isNegativeB = isNegative(divisor)
 
@@ -537,24 +551,28 @@ proc toInt128*(arg: float64): Int128 =
     return res
 
 proc maskUInt64*(arg: Int128): Int128 {.noinit, inline.} =
+  result = Zero
   result.udata[0] = arg.udata[0]
   result.udata[1] = arg.udata[1]
   result.udata[2] = 0
   result.udata[3] = 0
 
 proc maskUInt32*(arg: Int128): Int128 {.noinit, inline.} =
+  result = Zero
   result.udata[0] = arg.udata[0]
   result.udata[1] = 0
   result.udata[2] = 0
   result.udata[3] = 0
 
 proc maskUInt16*(arg: Int128): Int128 {.noinit, inline.} =
+  result = Zero
   result.udata[0] = arg.udata[0] and 0xffff
   result.udata[1] = 0
   result.udata[2] = 0
   result.udata[3] = 0
 
 proc maskUInt8*(arg: Int128): Int128 {.noinit, inline.} =
+  result = Zero
   result.udata[0] = arg.udata[0] and 0xff
   result.udata[1] = 0
   result.udata[2] = 0
@@ -571,4 +589,4 @@ proc maskBytes*(arg: Int128, numbytes: int): Int128 {.noinit.} =
   of 8:
     return maskUInt64(arg)
   else:
-    assert(false, "masking only implemented for 1, 2, 4 and 8 bytes")
+    raiseAssert "masking only implemented for 1, 2, 4 and 8 bytes"

compiler/isolation_check.nim

@@ -11,7 +11,9 @@
 ## https://github.com/nim-lang/RFCs/issues/244 for more details.
 
 import
-  ast, types, renderer, intsets
+  ast, types, renderer
+
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -21,6 +23,7 @@ proc canAlias(arg, ret: PType; marker: var IntSet): bool
 proc canAliasN(arg: PType; n: PNode; marker: var IntSet): bool =
   case n.kind
   of nkRecList:
+    result = false
     for i in 0..<n.len:
       result = canAliasN(arg, n[i], marker)
       if result: return
@@ -36,7 +39,7 @@ proc canAliasN(arg: PType; n: PNode; marker: var IntSet): bool =
       else: discard
   of nkSym:
     result = canAlias(arg, n.sym.typ, marker)
-  else: discard
+  else: result = false
 
 proc canAlias(arg, ret: PType; marker: var IntSet): bool =
   if containsOrIncl(marker, ret.id):
@@ -51,17 +54,18 @@ proc canAlias(arg, ret: PType; marker: var IntSet): bool =
   of tyObject:
     if isFinal(ret):
       result = canAliasN(arg, ret.n, marker)
-      if not result and ret.len > 0 and ret[0] != nil:
-        result = canAlias(arg, ret[0], marker)
+      if not result and ret.baseClass != nil:
+        result = canAlias(arg, ret.baseClass, marker)
     else:
       result = true
   of tyTuple:
-    for i in 0..<ret.len:
-      result = canAlias(arg, ret[i], marker)
+    result = false
+    for r in ret.kids:
+      result = canAlias(arg, r, marker)
       if result: break
   of tyArray, tySequence, tyDistinct, tyGenericInst,
      tyAlias, tyInferred, tySink, tyLent, tyOwned, tyRef:
-    result = canAlias(arg, ret.lastSon, marker)
+    result = canAlias(arg, ret.skipModifier, marker)
   of tyProc:
     result = ret.callConv == ccClosure
   else:
@@ -72,6 +76,71 @@ proc isValueOnlyType(t: PType): bool =
   proc wrap(t: PType): bool {.nimcall.} = t.kind in {tyRef, tyPtr, tyVar, tyLent}
   result = not types.searchTypeFor(t, wrap)
 
+type
+  SearchResult = enum
+    NotFound, Abort, Found
+
+proc containsDangerousRefAux(t: PType; marker: var IntSet): SearchResult
+
+proc containsDangerousRefAux(n: PNode; marker: var IntSet): SearchResult =
+  result = NotFound
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      result = containsDangerousRefAux(n[i], marker)
+      if result == Found: return result
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    result = containsDangerousRefAux(n[0], marker)
+    if result == Found: return result
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        result = containsDangerousRefAux(lastSon(n[i]), marker)
+        if result == Found: return result
+      else: discard
+  of nkSym:
+    result = containsDangerousRefAux(n.sym.typ, marker)
+  else: discard
+
+proc containsDangerousRefAux(t: PType; marker: var IntSet): SearchResult =
+  result = NotFound
+  if t == nil: return result
+  if containsOrIncl(marker, t.id): return result
+
+  if t.kind == tyRef or (t.kind == tyProc and t.callConv == ccClosure):
+    result = Found
+  elif tfSendable in t.flags:
+    result = Abort
+  else:
+    # continue the type traversal:
+    result = NotFound
+
+  if result != NotFound: return result
+  case t.kind
+  of tyObject:
+    if t.baseClass != nil:
+      result = containsDangerousRefAux(t.baseClass.skipTypes(skipPtrs), marker)
+    if result == NotFound: result = containsDangerousRefAux(t.n, marker)
+  of tyGenericInst, tyDistinct, tyAlias, tySink:
+    result = containsDangerousRefAux(skipModifier(t), marker)
+  of tyArray, tySet, tySequence:
+    result = containsDangerousRefAux(t.elementType, marker)
+  of tyTuple:
+    for a in t.kids:
+      result = containsDangerousRefAux(a, marker)
+      if result == Found: return result
+  else:
+    discard
+
+proc containsDangerousRef(t: PType): bool =
+  # a `ref` type is "dangerous" if it occurs not within a type that is like `Isolated[T]`.
+  # For example:
+  # `ref int` # dangerous
+  # `Isolated[ref int]` # not dangerous
+  var marker = initIntSet()
+  result = containsDangerousRefAux(t, marker) == Found
+
 proc canAlias*(arg, ret: PType): bool =
   if isValueOnlyType(arg):
     # can alias only with addr(arg.x) and we don't care if it is not safe
@@ -80,12 +149,15 @@ proc canAlias*(arg, ret: PType): bool =
     var marker = initIntSet()
     result = canAlias(arg, ret, marker)
 
+const
+  SomeVar = {skForVar, skParam, skVar, skLet, skConst, skResult, skTemp}
+
 proc containsVariable(n: PNode): bool =
   case n.kind
   of nodesToIgnoreSet:
     result = false
   of nkSym:
-    result = n.sym.kind in {skForVar, skParam, skVar, skLet, skConst, skResult, skTemp}
+    result = n.sym.kind in SomeVar
   else:
     for ch in n:
       if containsVariable(ch): return true
@@ -109,7 +181,7 @@ proc checkIsolate*(n: PNode): bool =
           discard "fine, it is isolated already"
         else:
           let argType = n[i].typ
-          if argType != nil and not isCompileTimeOnly(argType) and containsTyRef(argType):
+          if argType != nil and not isCompileTimeOnly(argType) and containsDangerousRef(argType):
             if argType.canAlias(n.typ) or containsVariable(n[i]):
               # bug #19013: Alias information is not enough, we need to check for potential
               # "overlaps". I claim the problem can only happen by reading again from a location
@@ -118,10 +190,12 @@ proc checkIsolate*(n: PNode): bool =
               return false
       result = true
     of nkIfStmt, nkIfExpr:
+      result = false
       for it in n:
         result = checkIsolate(it.lastSon)
         if not result: break
     of nkCaseStmt:
+      result = false
       for i in 1..<n.len:
         result = checkIsolate(n[i].lastSon)
         if not result: break
@@ -131,6 +205,7 @@ proc checkIsolate*(n: PNode): bool =
         result = checkIsolate(n[i].lastSon)
         if not result: break
     of nkBracket, nkTupleConstr, nkPar:
+      result = false
       for it in n:
         result = checkIsolate(it)
         if not result: break
@@ -143,6 +218,12 @@ proc checkIsolate*(n: PNode): bool =
         result = checkIsolate(n[^1])
       else:
         result = false
+    of nkSym:
+      result = true
+      if n.sym.kind in SomeVar:
+        let argType = n.typ
+        if argType != nil and not isCompileTimeOnly(argType) and containsDangerousRef(argType):
+          result = false
     else:
       # unanalysable expression:
       result = false

compiler/jstypes.nim

@@ -69,7 +69,7 @@ proc genObjectFields(p: PProc, typ: PType, n: PNode): Rope =
   else: internalError(p.config, n.info, "genObjectFields")
 
 proc objHasTypeField(t: PType): bool {.inline.} =
-  tfInheritable in t.flags or t[0] != nil
+  tfInheritable in t.flags or t.baseClass != nil
 
 proc genObjectInfo(p: PProc, typ: PType, name: Rope) =
   let kind = if objHasTypeField(typ): tyObject else: tyTuple
@@ -79,9 +79,9 @@ proc genObjectInfo(p: PProc, typ: PType, name: Rope) =
   p.g.typeInfo.addf("var NNI$1 = $2;$n",
        [rope(typ.id), genObjectFields(p, typ, typ.n)])
   p.g.typeInfo.addf("$1.node = NNI$2;$n", [name, rope(typ.id)])
-  if (typ.kind == tyObject) and (typ[0] != nil):
+  if (typ.kind == tyObject) and (typ.baseClass != nil):
     p.g.typeInfo.addf("$1.base = $2;$n",
-         [name, genTypeInfo(p, typ[0].skipTypes(skipPtrs))])
+         [name, genTypeInfo(p, typ.baseClass.skipTypes(skipPtrs))])
 
 proc genTupleFields(p: PProc, typ: PType): Rope =
   var s: Rope = ""
@@ -117,9 +117,9 @@ proc genEnumInfo(p: PProc, typ: PType, name: Rope) =
   prepend(p.g.typeInfo, s)
   p.g.typeInfo.add(n)
   p.g.typeInfo.addf("$1.node = NNI$2;$n", [name, rope(typ.id)])
-  if typ[0] != nil:
+  if typ.baseClass != nil:
     p.g.typeInfo.addf("$1.base = $2;$n",
-         [name, genTypeInfo(p, typ[0])])
+         [name, genTypeInfo(p, typ.baseClass)])
 
 proc genTypeInfo(p: PProc, typ: PType): Rope =
   let t = typ.skipTypes({tyGenericInst, tyDistinct, tyAlias, tySink, tyOwned})
@@ -127,7 +127,7 @@ proc genTypeInfo(p: PProc, typ: PType): Rope =
   if containsOrIncl(p.g.typeInfoGenerated, t.id): return
   case t.kind
   of tyDistinct:
-    result = genTypeInfo(p, t[0])
+    result = genTypeInfo(p, t.skipModifier)
   of tyPointer, tyProc, tyBool, tyChar, tyCstring, tyString, tyInt..tyUInt64:
     var s =
       "var $1 = {size: 0,kind: $2,base: null,node: null,finalizer: null};$n" %
@@ -139,18 +139,18 @@ proc genTypeInfo(p: PProc, typ: PType): Rope =
               [result, rope(ord(t.kind))]
     prepend(p.g.typeInfo, s)
     p.g.typeInfo.addf("$1.base = $2;$n",
-         [result, genTypeInfo(p, t.lastSon)])
+         [result, genTypeInfo(p, t.elementType)])
   of tyArray:
     var s =
       "var $1 = {size: 0, kind: $2, base: null, node: null, finalizer: null};$n" %
               [result, rope(ord(t.kind))]
     prepend(p.g.typeInfo, s)
     p.g.typeInfo.addf("$1.base = $2;$n",
-         [result, genTypeInfo(p, t[1])])
+         [result, genTypeInfo(p, t.elementType)])
   of tyEnum: genEnumInfo(p, t, result)
   of tyObject: genObjectInfo(p, t, result)
   of tyTuple: genTupleInfo(p, t, result)
   of tyStatic:
-    if t.n != nil: result = genTypeInfo(p, lastSon t)
+    if t.n != nil: result = genTypeInfo(p, skipModifier t)
     else: internalError(p.config, "genTypeInfo(" & $t.kind & ')')
   else: internalError(p.config, "genTypeInfo(" & $t.kind & ')')

compiler/lambdalifting.nim

@@ -10,10 +10,12 @@
 # This file implements lambda lifting for the transformator.
 
 import
-  intsets, strutils, options, ast, astalgo, msgs,
-  idents, renderer, types, magicsys, lowerings, tables, modulegraphs, lineinfos,
+  options, ast, astalgo, msgs,
+  idents, renderer, types, magicsys, lowerings, modulegraphs, lineinfos,
   transf, liftdestructors, typeallowed
 
+import std/[strutils, tables, intsets]
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -133,14 +135,14 @@ proc createClosureIterStateType*(g: ModuleGraph; iter: PSym; idgen: IdGenerator)
   var n = newNodeI(nkRange, iter.info)
   n.add newIntNode(nkIntLit, -1)
   n.add newIntNode(nkIntLit, 0)
-  result = newType(tyRange, nextTypeId(idgen), iter)
+  result = newType(tyRange, idgen, iter)
   result.n = n
   var intType = nilOrSysInt(g)
-  if intType.isNil: intType = newType(tyInt, nextTypeId(idgen), iter)
+  if intType.isNil: intType = newType(tyInt, idgen, iter)
   rawAddSon(result, intType)
 
 proc createStateField(g: ModuleGraph; iter: PSym; idgen: IdGenerator): PSym =
-  result = newSym(skField, getIdent(g.cache, ":state"), nextSymId(idgen), iter, iter.info)
+  result = newSym(skField, getIdent(g.cache, ":state"), idgen, iter, iter.info)
   result.typ = createClosureIterStateType(g, iter, idgen)
 
 proc createEnvObj(g: ModuleGraph; idgen: IdGenerator; owner: PSym; info: TLineInfo): PType =
@@ -154,8 +156,8 @@ proc getClosureIterResult*(g: ModuleGraph; iter: PSym; idgen: IdGenerator): PSym
     result = iter.ast[resultPos].sym
   else:
     # XXX a bit hacky:
-    result = newSym(skResult, getIdent(g.cache, ":result"), nextSymId(idgen), iter, iter.info, {})
-    result.typ = iter.typ[0]
+    result = newSym(skResult, getIdent(g.cache, ":result"), idgen, iter, iter.info, {})
+    result.typ = iter.typ.returnType
     incl(result.flags, sfUsed)
     iter.ast.add newSymNode(result)
 
@@ -187,6 +189,8 @@ proc getEnvParam*(routine: PSym): PSym =
   if hidden.kind == nkSym and hidden.sym.name.s == paramName:
     result = hidden.sym
     assert sfFromGeneric in result.flags
+  else:
+    result = nil
 
 proc interestingVar(s: PSym): bool {.inline.} =
   result = s.kind in {skVar, skLet, skTemp, skForVar, skParam, skResult} and
@@ -199,6 +203,8 @@ proc illegalCapture(s: PSym): bool {.inline.} =
 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:
+    result = false
 
 proc newAsgnStmt(le, ri: PNode, info: TLineInfo): PNode =
   # Bugfix: unfortunately we cannot use 'nkFastAsgn' here as that would
@@ -233,14 +239,9 @@ proc interestingIterVar(s: PSym): bool {.inline.} =
 template isIterator*(owner: PSym): bool =
   owner.kind == skIterator and owner.typ.callConv == ccClosure
 
-proc liftingHarmful(conf: ConfigRef; owner: PSym): bool {.inline.} =
-  ## lambda lifting can be harmful for JS-like code generators.
-  let isCompileTime = sfCompileTime in owner.flags or owner.kind == skMacro
-  result = conf.backend == backendJs and not isCompileTime
-
 proc createTypeBoundOpsLL(g: ModuleGraph; refType: PType; info: TLineInfo; idgen: IdGenerator; owner: PSym) =
   if owner.kind != skMacro:
-    createTypeBoundOps(g, nil, refType.lastSon, info, 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:
       owner.flags.incl sfInjectDestructors
@@ -254,12 +255,10 @@ proc genCreateEnv(env: PNode): PNode =
 
 proc liftIterSym*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PNode =
   # transforms  (iter)  to  (let env = newClosure[iter](); (iter, env))
-  if liftingHarmful(g.config, owner): return n
   let iter = n.sym
   assert iter.isIterator
 
-  result = newNodeIT(nkStmtListExpr, n.info, n.typ)
-
+  result = newNodeIT(nkStmtListExpr, n.info, iter.typ)
   let hp = getHiddenParam(g, iter)
   var env: PNode
   if owner.isIterator:
@@ -267,7 +266,7 @@ proc liftIterSym*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PN
     addUniqueField(it.typ.skipTypes({tyOwned})[0], hp, g.cache, idgen)
     env = indirectAccess(newSymNode(it), hp, hp.info)
   else:
-    let e = newSym(skLet, iter.name, nextSymId(idgen), owner, n.info)
+    let e = newSym(skLet, iter.name, idgen, owner, n.info)
     e.typ = hp.typ
     e.flags = hp.flags
     env = newSymNode(e)
@@ -293,33 +292,34 @@ proc freshVarForClosureIter*(g: ModuleGraph; s: PSym; idgen: IdGenerator; owner:
 
 proc markAsClosure(g: ModuleGraph; owner: PSym; n: PNode) =
   let s = n.sym
+  let isEnv = s.name.id == getIdent(g.cache, ":env").id
   if illegalCapture(s):
     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 $2> which can be captured.") %
       [s.name.s, typeToString(s.typ), g.config$s.info])
-  elif not (owner.typ.callConv == ccClosure or owner.typ.callConv == ccNimCall and tfExplicitCallConv notin owner.typ.flags):
+  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])
   incl(owner.typ.flags, tfCapturesEnv)
-  owner.typ.callConv = ccClosure
+  if not isEnv:
+    owner.typ.callConv = ccClosure
 
 type
   DetectionPass = object
     processed, capturedVars: IntSet
     ownerToType: Table[int, PType]
     somethingToDo: bool
+    inTypeOf: bool
     graph: ModuleGraph
     idgen: IdGenerator
 
 proc initDetectionPass(g: ModuleGraph; fn: PSym; idgen: IdGenerator): DetectionPass =
-  result.processed = initIntSet()
-  result.capturedVars = initIntSet()
-  result.ownerToType = initTable[int, PType]()
-  result.processed.incl(fn.id)
-  result.graph = g
-  result.idgen = idgen
+  result = DetectionPass(processed: toIntSet([fn.id]),
+    capturedVars: initIntSet(), ownerToType: initTable[int, PType](),
+    graph: g, idgen: idgen
+  )
 
 discard """
 proc outer =
@@ -335,7 +335,7 @@ proc getEnvTypeForOwner(c: var DetectionPass; owner: PSym;
                         info: TLineInfo): PType =
   result = c.ownerToType.getOrDefault(owner.id)
   if result.isNil:
-    result = newType(tyRef, nextTypeId(c.idgen), owner)
+    result = newType(tyRef, c.idgen, owner)
     let obj = createEnvObj(c.graph, c.idgen, owner, info)
     rawAddSon(result, obj)
     c.ownerToType[owner.id] = result
@@ -343,7 +343,7 @@ proc getEnvTypeForOwner(c: var DetectionPass; owner: PSym;
 proc asOwnedRef(c: var DetectionPass; t: PType): PType =
   if optOwnedRefs in c.graph.config.globalOptions:
     assert t.kind == tyRef
-    result = newType(tyOwned, nextTypeId(c.idgen), t.owner)
+    result = newType(tyOwned, c.idgen, t.owner)
     result.flags.incl tfHasOwned
     result.rawAddSon t
   else:
@@ -352,7 +352,7 @@ proc asOwnedRef(c: var DetectionPass; t: PType): PType =
 proc getEnvTypeForOwnerUp(c: var DetectionPass; owner: PSym;
                           info: TLineInfo): PType =
   var r = c.getEnvTypeForOwner(owner, info)
-  result = newType(tyPtr, nextTypeId(c.idgen), owner)
+  result = newType(tyPtr, c.idgen, owner)
   rawAddSon(result, r.skipTypes({tyOwned, tyRef, tyPtr}))
 
 proc createUpField(c: var DetectionPass; dest, dep: PSym; info: TLineInfo) =
@@ -380,7 +380,7 @@ proc createUpField(c: var DetectionPass; dest, dep: PSym; info: TLineInfo) =
       if c.graph.config.selectedGC == gcDestructors and sfCursor notin upField.flags:
         localError(c.graph.config, dep.info, "internal error: up reference is not a .cursor")
   else:
-    let result = newSym(skField, upIdent, nextSymId(c.idgen), obj.owner, obj.owner.info)
+    let result = newSym(skField, upIdent, c.idgen, obj.owner, obj.owner.info)
     result.typ = fieldType
     when false:
       if c.graph.config.selectedGC == gcDestructors:
@@ -413,12 +413,15 @@ Consider:
 
 """
 
+proc isTypeOf(n: PNode): bool =
+  n.kind == nkSym and n.sym.magic in {mTypeOf, mType}
+
 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), nextSymId(c.idgen), fn, fn.info)
+    cp = newSym(skParam, getIdent(c.graph.cache, paramName), c.idgen, fn, fn.info)
     incl(cp.flags, sfFromGeneric)
     cp.typ = t
     addHiddenParam(fn, cp)
@@ -441,24 +444,28 @@ proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
     if innerProc:
       if s.isIterator: c.somethingToDo = true
       if not c.processed.containsOrIncl(s.id):
-        let body = transformBody(c.graph, c.idgen, s, useCache)
+        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
+    let interested = interestingVar(s)
     if ow == owner:
       if owner.isIterator:
         c.somethingToDo = true
         addClosureParam(c, owner, n.info)
         if interestingIterVar(s):
-          if not c.capturedVars.containsOrIncl(s.id):
+          if not c.capturedVars.contains(s.id):
+            if not c.inTypeOf: c.capturedVars.incl(s.id)
             let obj = getHiddenParam(c.graph, owner).typ.skipTypes({tyOwned, tyRef, tyPtr})
             #let obj = c.getEnvTypeForOwner(s.owner).skipTypes({tyOwned, tyRef, tyPtr})
 
             if s.name.id == getIdent(c.graph.cache, ":state").id:
+              obj.n[0].sym.flags.incl sfNoInit
               obj.n[0].sym.itemId = ItemId(module: s.itemId.module, item: -s.itemId.item)
             else:
               discard addField(obj, s, c.graph.cache, c.idgen)
     # direct or indirect dependency:
-    elif (innerProc and not s.isIterator and s.typ.callConv == ccClosure) or interestingVar(s):
+    elif innerClosure or interested:
       discard """
         proc outer() =
           var x: int
@@ -475,10 +482,12 @@ proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
       addClosureParam(c, owner, n.info)
       #echo "capturing ", n.info
       # variable 's' is actually captured:
-      if interestingVar(s) and not c.capturedVars.containsOrIncl(s.id):
-        let obj = c.getEnvTypeForOwner(ow, n.info).skipTypes({tyOwned, tyRef, tyPtr})
-        #getHiddenParam(owner).typ.skipTypes({tyOwned, tyRef, tyPtr})
-        discard addField(obj, s, c.graph.cache, c.idgen)
+      if interestingVar(s):
+        if not c.capturedVars.contains(s.id):
+          if not c.inTypeOf: c.capturedVars.incl(s.id)
+          let obj = c.getEnvTypeForOwner(ow, n.info).skipTypes({tyOwned, tyRef, tyPtr})
+          #getHiddenParam(owner).typ.skipTypes({tyOwned, tyRef, tyPtr})
+          discard addField(obj, s, c.graph.cache, c.idgen)
       # create required upFields:
       var w = owner.skipGenericOwner
       if isInnerProc(w) or owner.isIterator:
@@ -510,9 +519,14 @@ proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
       detectCapturedVars(n[namePos], owner, c)
   of nkReturnStmt:
     detectCapturedVars(n[0], owner, c)
+  of nkIdentDefs:
+    detectCapturedVars(n[^1], owner, c)
   else:
+    if n.isCallExpr and n[0].isTypeOf:
+      c.inTypeOf = true
     for i in 0..<n.len:
       detectCapturedVars(n[i], owner, c)
+    c.inTypeOf = false
 
 type
   LiftingPass = object
@@ -522,9 +536,8 @@ type
     unownedEnvVars: Table[int, PNode] # only required for --newruntime
 
 proc initLiftingPass(fn: PSym): LiftingPass =
-  result.processed = initIntSet()
-  result.processed.incl(fn.id)
-  result.envVars = initTable[int, PNode]()
+  result = LiftingPass(processed: toIntSet([fn.id]),
+                envVars: initTable[int, PNode]())
 
 proc accessViaEnvParam(g: ModuleGraph; n: PNode; owner: PSym): PNode =
   let s = n.sym
@@ -532,8 +545,8 @@ proc accessViaEnvParam(g: ModuleGraph; n: PNode; owner: PSym): PNode =
   let envParam = getHiddenParam(g, owner)
   if not envParam.isNil:
     var access = newSymNode(envParam)
+    var obj = access.typ.elementType
     while true:
-      let obj = access.typ[0]
       assert obj.kind == tyObject
       let field = getFieldFromObj(obj, s)
       if field != nil:
@@ -541,18 +554,19 @@ proc accessViaEnvParam(g: ModuleGraph; n: PNode; owner: PSym): PNode =
       let upField = lookupInRecord(obj.n, getIdent(g.cache, upName))
       if upField == nil: break
       access = rawIndirectAccess(access, upField, n.info)
+      obj = access.typ.baseClass
   localError(g.config, n.info, "internal error: environment misses: " & s.name.s)
   result = n
 
 proc newEnvVar(cache: IdentCache; owner: PSym; typ: PType; info: TLineInfo; idgen: IdGenerator): PNode =
-  var v = newSym(skVar, getIdent(cache, envName), nextSymId(idgen), owner, info)
+  var v = newSym(skVar, getIdent(cache, envName), idgen, owner, info)
   v.flags = {sfShadowed, sfGeneratedOp}
   v.typ = typ
   result = newSymNode(v)
   when false:
     if owner.kind == skIterator and owner.typ.callConv == ccClosure:
       let it = getHiddenParam(owner)
-      addUniqueField(it.typ[0], v)
+      addUniqueField(it.typ.elementType, v)
       result = indirectAccess(newSymNode(it), v, v.info)
     else:
       result = newSymNode(v)
@@ -569,7 +583,7 @@ proc setupEnvVar(owner: PSym; d: var DetectionPass;
     result = newEnvVar(d.graph.cache, owner, asOwnedRef(d, envVarType), info, d.idgen)
     c.envVars[owner.id] = result
     if optOwnedRefs in d.graph.config.globalOptions:
-      var v = newSym(skVar, getIdent(d.graph.cache, envName & "Alt"), nextSymId d.idgen, owner, info)
+      var v = newSym(skVar, getIdent(d.graph.cache, envName & "Alt"), d.idgen, owner, info)
       v.flags = {sfShadowed, sfGeneratedOp}
       v.typ = envVarType
       c.unownedEnvVars[owner.id] = newSymNode(v)
@@ -653,7 +667,7 @@ proc closureCreationForIter(iter: PNode;
                             d: var DetectionPass; c: var LiftingPass): PNode =
   result = newNodeIT(nkStmtListExpr, iter.info, iter.sym.typ)
   let owner = iter.sym.skipGenericOwner
-  var v = newSym(skVar, getIdent(d.graph.cache, envName), nextSymId(d.idgen), owner, iter.info)
+  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
@@ -711,6 +725,7 @@ proc symToClosure(n: PNode; owner: PSym; d: var DetectionPass;
     # direct dependency, so use the outer's env variable:
     result = makeClosure(d.graph, d.idgen, s, setupEnvVar(owner, d, c, n.info), n.info)
   else:
+    result = nil
     let available = getHiddenParam(d.graph, owner)
     let wanted = getHiddenParam(d.graph, s).typ
     # ugh: call through some other inner proc;
@@ -737,7 +752,7 @@ proc liftCapturedVars(n: PNode; owner: PSym; d: var DetectionPass;
         #  echo renderTree(s.getBody, {renderIds})
         let oldInContainer = c.inContainer
         c.inContainer = 0
-        var body = transformBody(d.graph, d.idgen, s, dontUseCache)
+        var body = transformBody(d.graph, d.idgen, s, {})
         body = liftCapturedVars(body, s, d, c)
         if c.envVars.getOrDefault(s.id).isNil:
           s.transformedBody = body
@@ -792,6 +807,8 @@ proc liftCapturedVars(n: PNode; owner: PSym; d: var DetectionPass;
   of nkTypeOfExpr:
     result = n
   else:
+    if n.isCallExpr and n[0].isTypeOf:
+      return
     if owner.isIterator:
       if nfLL in n.flags:
         # special case 'when nimVm' due to bug #3636:
@@ -859,16 +876,11 @@ proc liftIterToProc*(g: ModuleGraph; fn: PSym; body: PNode; ptrType: PType;
   fn.typ.callConv = oldCC
 
 proc liftLambdas*(g: ModuleGraph; fn: PSym, body: PNode; tooEarly: var bool;
-                  idgen: IdGenerator, force: bool): PNode =
-  # XXX backend == backendJs does not suffice! The compiletime stuff needs
-  # the transformation even when compiling to JS ...
-
-  # However we can do lifting for the stuff which is *only* compiletime.
+                  idgen: IdGenerator; flags: TransformFlags): PNode =
   let isCompileTime = sfCompileTime in fn.flags or fn.kind == skMacro
 
-  if body.kind == nkEmpty or (
-      g.config.backend == backendJs and not isCompileTime) or
-      (fn.skipGenericOwner.kind != skModule and not force):
+  if body.kind == nkEmpty or
+      (fn.skipGenericOwner.kind != skModule and force notin flags):
 
     # ignore forward declaration:
     result = body
@@ -927,7 +939,6 @@ proc liftForLoop*(g: ModuleGraph; body: PNode; idgen: IdGenerator; owner: PSym):
           break
         ...
     """
-  if liftingHarmful(g.config, owner): return body
   if not (body.kind == nkForStmt and body[^2].kind in nkCallKinds):
     localError(g.config, body.info, "ignored invalid for loop")
     return body
@@ -936,14 +947,14 @@ proc liftForLoop*(g: ModuleGraph; body: PNode; idgen: IdGenerator; owner: PSym):
   result = newNodeI(nkStmtList, body.info)
 
   # static binding?
-  var env: PSym
+  var env: PSym = nil
   let op = call[0]
   if op.kind == nkSym and op.sym.isIterator:
     # createClosure()
     let iter = op.sym
 
     let hp = getHiddenParam(g, iter)
-    env = newSym(skLet, iter.name, nextSymId(idgen), owner, body.info)
+    env = newSym(skLet, iter.name, idgen, owner, body.info)
     env.typ = hp.typ
     env.flags = hp.flags
 
@@ -971,12 +982,15 @@ proc liftForLoop*(g: ModuleGraph; body: PNode; idgen: IdGenerator; owner: PSym):
   # gather vars in a tuple:
   var v2 = newNodeI(nkLetSection, body.info)
   var vpart = newNodeI(if body.len == 3: nkIdentDefs else: nkVarTuple, body.info)
-  for i in 0..<body.len-2:
-    if body[i].kind == nkSym:
-      body[i].sym.transitionToLet()
-    vpart.add body[i]
+  if body.len == 3 and body[0].kind == nkVarTuple:
+    vpart = body[0] # fixes for (i,j) in walk() # bug #15924
+  else:
+    for i in 0..<body.len-2:
+      if body[i].kind == nkSym:
+        body[i].sym.transitionToLet()
+      vpart.add body[i]
 
-  vpart.add newNodeI(nkEmpty, body.info) # no explicit type
+    vpart.add newNodeI(nkEmpty, body.info) # no explicit type
   if not env.isNil:
     call[0] = makeClosure(g, idgen, call[0].sym, env.newSymNode, body.info)
   vpart.add call

compiler/layouter.nim

@@ -9,7 +9,7 @@
 
 ## Layouter for nimpretty.
 
-import idents, lexer, lineinfos, llstream, options, msgs, strutils, pathutils
+import idents, lexer, ast, lineinfos, llstream, options, msgs, strutils, pathutils
 
 const
   MinLineLen = 15
@@ -243,23 +243,28 @@ proc renderTokens*(em: var Emitter): string =
 
   return content
 
-proc writeOut*(em: Emitter, content: string)  =
+type
+  FinalCheck = proc (content: string; origAst: PNode): bool {.nimcall.}
+
+proc writeOut*(em: Emitter; content: string; origAst: PNode; check: FinalCheck) =
   ## Write to disk
   let outFile = em.config.absOutFile
   if fileExists(outFile) and readFile(outFile.string) == content:
     discard "do nothing, see #9499"
     return
-  var f = llStreamOpen(outFile, fmWrite)
-  if f == nil:
-    rawMessage(em.config, errGenerated, "cannot open file: " & outFile.string)
-    return
-  f.llStreamWrite content
-  llStreamClose(f)
 
-proc closeEmitter*(em: var Emitter) =
+  if check(content, origAst):
+    var f = llStreamOpen(outFile, fmWrite)
+    if f == nil:
+      rawMessage(em.config, errGenerated, "cannot open file: " & outFile.string)
+      return
+    f.llStreamWrite content
+    llStreamClose(f)
+
+proc closeEmitter*(em: var Emitter; origAst: PNode; check: FinalCheck) =
   ## Renders emitter tokens and write to a file
   let content = renderTokens(em)
-  em.writeOut(content)
+  em.writeOut(content, origAst, check)
 
 proc wr(em: var Emitter; x: string; lt: LayoutToken) =
   em.tokens.add x
@@ -510,7 +515,7 @@ proc emitTok*(em: var Emitter; L: Lexer; tok: Token) =
     rememberSplit(splitComma)
     wrSpace em
   of openPars:
-    if tok.strongSpaceA and not em.endsInWhite and
+    if tsLeading in tok.spacing and not em.endsInWhite and
         (not em.wasExportMarker or tok.tokType == tkCurlyDotLe):
       wrSpace em
     wr(em, $tok.tokType, ltSomeParLe)
@@ -528,7 +533,7 @@ proc emitTok*(em: var Emitter; L: Lexer; tok: Token) =
     wr(em, $tok.tokType, ltOther)
     if not em.inquote: wrSpace(em)
   of tkOpr, tkDotDot:
-    if em.inquote or (((not tok.strongSpaceA) and tok.strongSpaceB == tsNone) and
+    if em.inquote or (tok.spacing == {} and
         tok.ident.s notin ["<", ">", "<=", ">=", "==", "!="]):
       # bug #9504: remember to not spacify a keyword:
       lastTokWasTerse = true
@@ -538,7 +543,7 @@ proc emitTok*(em: var Emitter; L: Lexer; tok: Token) =
       if not em.endsInWhite: wrSpace(em)
       wr(em, tok.ident.s, ltOpr)
       template isUnary(tok): bool =
-        tok.strongSpaceB == tsNone and tok.strongSpaceA
+        tok.spacing == {tsLeading}
 
       if not isUnary(tok):
         rememberSplit(splitBinary)

compiler/lexer.nim

@@ -16,14 +16,15 @@
 # DOS or Macintosh text files, even when it is not the native format.
 
 import
-  hashes, options, msgs, strutils, platform, idents, nimlexbase, llstream,
-  wordrecg, lineinfos, pathutils, parseutils
+  options, msgs, platform, idents, nimlexbase, llstream,
+  wordrecg, lineinfos, pathutils
+
+import std/[hashes, parseutils, strutils]
 
 when defined(nimPreviewSlimSystem):
   import std/[assertions, formatfloat]
 
 const
-  MaxLineLength* = 80         # lines longer than this lead to a warning
   numChars*: set[char] = {'0'..'9', 'a'..'z', 'A'..'Z'}
   SymChars*: set[char] = {'a'..'z', 'A'..'Z', '0'..'9', '\x80'..'\xFF'}
   SymStartChars*: set[char] = {'a'..'z', 'A'..'Z', '\x80'..'\xFF'}
@@ -94,19 +95,18 @@ type
     base2, base8, base16
 
   TokenSpacing* = enum
-    tsNone, tsTrailing, tsEof
+    tsLeading, tsTrailing, tsEof
 
   Token* = object                # a Nim token
     tokType*: TokType            # the type of the token
+    base*: NumericalBase         # the numerical base; only valid for int
+                                 # or float literals
+    spacing*: set[TokenSpacing]  # spaces around token
     indent*: int                 # the indentation; != -1 if the token has been
                                  # preceded with indentation
     ident*: PIdent               # the parsed identifier
     iNumber*: BiggestInt         # the parsed integer literal
     fNumber*: BiggestFloat       # the parsed floating point literal
-    base*: NumericalBase         # the numerical base; only valid for int
-                                 # or float literals
-    strongSpaceA*: bool          # leading spaces of an operator
-    strongSpaceB*: TokenSpacing  # trailing spaces of an operator
     literal*: string             # the parsed (string) literal; and
                                  # documentation comments are here too
     line*, col*: int
@@ -122,7 +122,6 @@ type
                               # this is needed because scanning comments
                               # needs so much look-ahead
     currLineIndent*: int
-    strongSpaces*, allowTabs*: bool
     errorHandler*: ErrorHandler
     cache*: IdentCache
     when defined(nimsuggest):
@@ -150,9 +149,11 @@ proc isNimIdentifier*(s: string): bool =
     var i = 1
     while i < sLen:
       if s[i] == '_': inc(i)
-      if i < sLen and s[i] notin SymChars: return
+      if i < sLen and s[i] notin SymChars: return false
       inc(i)
     result = true
+  else:
+    result = false
 
 proc `$`*(tok: Token): string =
   case tok.tokType
@@ -174,32 +175,6 @@ proc printTok*(conf: ConfigRef; tok: Token) =
   # xxx factor with toLocation
   msgWriteln(conf, $tok.line & ":" & $tok.col & "\t" & $tok.tokType & " " & $tok)
 
-proc initToken*(L: var Token) =
-  L.tokType = tkInvalid
-  L.iNumber = 0
-  L.indent = 0
-  L.strongSpaceA = false
-  L.literal = ""
-  L.fNumber = 0.0
-  L.base = base10
-  L.ident = nil
-  when defined(nimpretty):
-    L.commentOffsetA = 0
-    L.commentOffsetB = 0
-
-proc fillToken(L: var Token) =
-  L.tokType = tkInvalid
-  L.iNumber = 0
-  L.indent = 0
-  L.strongSpaceA = false
-  setLen(L.literal, 0)
-  L.fNumber = 0.0
-  L.base = base10
-  L.ident = nil
-  when defined(nimpretty):
-    L.commentOffsetA = 0
-    L.commentOffsetB = 0
-
 proc openLexer*(lex: var Lexer, fileIdx: FileIndex, inputstream: PLLStream;
                  cache: IdentCache; config: ConfigRef) =
   openBaseLexer(lex, inputstream)
@@ -325,8 +300,7 @@ proc getNumber(L: var Lexer, result: var Token) =
     # Used to get slightly human friendlier err messages.
     const literalishChars = {'A'..'Z', 'a'..'z', '0'..'9', '_', '.', '\''}
     var msgPos = L.bufpos
-    var t: Token
-    t.literal = ""
+    var t = Token(literal: "")
     L.bufpos = startpos # Use L.bufpos as pos because of matchChars
     matchChars(L, t, literalishChars)
     # We must verify +/- specifically so that we're not past the literal
@@ -539,8 +513,8 @@ proc getNumber(L: var Lexer, result: var Token) =
         of floatTypes:
           result.fNumber = parseFloat(result.literal)
         of tkUInt64Lit, tkUIntLit:
-          var iNumber: uint64
-          var len: int
+          var iNumber: uint64 = uint64(0)
+          var len: int = 0
           try:
             len = parseBiggestUInt(result.literal, iNumber)
           except ValueError:
@@ -549,8 +523,8 @@ proc getNumber(L: var Lexer, result: var Token) =
             raise newException(ValueError, "invalid integer: " & result.literal)
           result.iNumber = cast[int64](iNumber)
         else:
-          var iNumber: int64
-          var len: int
+          var iNumber: int64 = int64(0)
+          var len: int = 0
           try:
             len = parseBiggestInt(result.literal, iNumber)
           except ValueError:
@@ -737,10 +711,6 @@ proc handleCRLF(L: var Lexer, pos: int): int =
   template registerLine =
     let col = L.getColNumber(pos)
 
-    when not defined(nimpretty):
-      if col > MaxLineLength:
-        lexMessagePos(L, hintLineTooLong, pos)
-
   case L.buf[pos]
   of CR:
     registerLine()
@@ -800,7 +770,7 @@ proc getString(L: var Lexer, tok: var Token, mode: StringMode) =
     if mode != normal: tok.tokType = tkRStrLit
     else: tok.tokType = tkStrLit
     while true:
-      var c = L.buf[pos]
+      let c = L.buf[pos]
       if c == '\"':
         if mode != normal and L.buf[pos+1] == '\"':
           inc(pos, 2)
@@ -826,7 +796,7 @@ proc getCharacter(L: var Lexer; tok: var Token) =
   tokenBegin(tok, L.bufpos)
   let startPos = L.bufpos
   inc(L.bufpos)               # skip '
-  var c = L.buf[L.bufpos]
+  let c = L.buf[L.bufpos]
   case c
   of '\0'..pred(' '), '\'':
     lexMessage(L, errGenerated, "invalid character literal")
@@ -944,7 +914,7 @@ proc getOperator(L: var Lexer, tok: var Token) =
   tokenBegin(tok, pos)
   var h: Hash = 0
   while true:
-    var c = L.buf[pos]
+    let c = L.buf[pos]
     if c in OpChars:
       h = h !& ord(c)
       inc(pos)
@@ -960,13 +930,15 @@ proc getOperator(L: var Lexer, tok: var Token) =
   tokenEnd(tok, pos-1)
   # advance pos but don't store it in L.bufpos so the next token (which might
   # be an operator too) gets the preceding spaces:
-  tok.strongSpaceB = tsNone
+  tok.spacing = tok.spacing - {tsTrailing, tsEof}
+  var trailing = false
   while L.buf[pos] == ' ':
     inc pos
-    if tok.strongSpaceB != tsTrailing:
-      tok.strongSpaceB = tsTrailing
+    trailing = true
   if L.buf[pos] in {CR, LF, nimlexbase.EndOfFile}:
-    tok.strongSpaceB = tsEof
+    tok.spacing.incl(tsEof)
+  elif trailing:
+    tok.spacing.incl(tsTrailing)
 
 proc getPrecedence*(tok: Token): int =
   ## Calculates the precedence of the given token.
@@ -1010,22 +982,6 @@ proc getPrecedence*(tok: Token): int =
   of tkOr, tkXor, tkPtr, tkRef: result = 3
   else: return -10
 
-proc newlineFollows*(L: Lexer): bool =
-  var pos = L.bufpos
-  while true:
-    case L.buf[pos]
-    of ' ', '\t':
-      inc(pos)
-    of CR, LF:
-      result = true
-      break
-    of '#':
-      inc(pos)
-      if L.buf[pos] == '#': inc(pos)
-      if L.buf[pos] != '[': return true
-    else:
-      break
-
 proc skipMultiLineComment(L: var Lexer; tok: var Token; start: int;
                           isDoc: bool) =
   var pos = start
@@ -1077,7 +1033,6 @@ proc skipMultiLineComment(L: var Lexer; tok: var Token; start: int;
       when defined(nimpretty): tok.literal.add "\L"
       if isDoc:
         when not defined(nimpretty): tok.literal.add "\n"
-        inc tok.iNumber
         var c = toStrip
         while L.buf[pos] == ' ' and c > 0:
           inc pos
@@ -1096,8 +1051,6 @@ proc skipMultiLineComment(L: var Lexer; tok: var Token; start: int;
 proc scanComment(L: var Lexer, tok: var Token) =
   var pos = L.bufpos
   tok.tokType = tkComment
-  # iNumber contains the number of '\n' in the token
-  tok.iNumber = 0
   assert L.buf[pos+1] == '#'
   when defined(nimpretty):
     tok.commentOffsetA = L.offsetBase + pos
@@ -1120,9 +1073,7 @@ proc scanComment(L: var Lexer, tok: var Token) =
         toStrip = 0
       else:  # found first non-whitespace character
         stripInit = true
-    var lastBackslash = -1
     while L.buf[pos] notin {CR, LF, nimlexbase.EndOfFile}:
-      if L.buf[pos] == '\\': lastBackslash = pos+1
       tok.literal.add(L.buf[pos])
       inc(pos)
     tokenEndIgnore(tok, pos)
@@ -1140,7 +1091,6 @@ proc scanComment(L: var Lexer, tok: var Token) =
         while L.buf[pos] == ' ' and c > 0:
           inc pos
           dec c
-        inc tok.iNumber
     else:
       if L.buf[pos] > ' ':
         L.indentAhead = indent
@@ -1153,7 +1103,7 @@ proc scanComment(L: var Lexer, tok: var Token) =
 proc skip(L: var Lexer, tok: var Token) =
   var pos = L.bufpos
   tokenBegin(tok, pos)
-  tok.strongSpaceA = false
+  tok.spacing.excl(tsLeading)
   when defined(nimpretty):
     var hasComment = false
     var commentIndent = L.currLineIndent
@@ -1164,10 +1114,9 @@ proc skip(L: var Lexer, tok: var Token) =
     case L.buf[pos]
     of ' ':
       inc(pos)
-      if not tok.strongSpaceA:
-        tok.strongSpaceA = true
+      tok.spacing.incl(tsLeading)
     of '\t':
-      if not L.allowTabs: lexMessagePos(L, errGenerated, pos, "tabs are not allowed, use spaces instead")
+      lexMessagePos(L, errGenerated, pos, "tabs are not allowed, use spaces instead")
       inc(pos)
     of CR, LF:
       tokenEndPrevious(tok, pos)
@@ -1187,7 +1136,7 @@ proc skip(L: var Lexer, tok: var Token) =
           pos = L.bufpos
         else:
           break
-      tok.strongSpaceA = false
+      tok.spacing.excl(tsLeading)
       when defined(nimpretty):
         if L.buf[pos] == '#' and tok.line < 0: commentIndent = indent
       if L.buf[pos] > ' ' and (L.buf[pos] != '#' or L.buf[pos+1] == '#'):
@@ -1235,7 +1184,7 @@ proc rawGetTok*(L: var Lexer, tok: var Token) =
         L.previousToken.line = tok.line.uint16
         L.previousToken.col = tok.col.int16
 
-  fillToken(tok)
+  reset(tok)
   if L.indentAhead >= 0:
     tok.indent = L.indentAhead
     L.currLineIndent = L.indentAhead
@@ -1247,7 +1196,7 @@ proc rawGetTok*(L: var Lexer, tok: var Token) =
     if tok.tokType == tkComment:
       L.indentAhead = L.currLineIndent
       return
-  var c = L.buf[L.bufpos]
+  let c = L.buf[L.bufpos]
   tok.line = L.lineNumber
   tok.col = getColNumber(L, L.bufpos)
   if c in SymStartChars - {'r', 'R'} - UnicodeOperatorStartChars:
@@ -1403,9 +1352,9 @@ proc rawGetTok*(L: var Lexer, tok: var Token) =
 
 proc getIndentWidth*(fileIdx: FileIndex, inputstream: PLLStream;
                      cache: IdentCache; config: ConfigRef): int =
-  var lex: Lexer
-  var tok: Token
-  initToken(tok)
+  result = 0
+  var lex: Lexer = default(Lexer)
+  var tok: Token = default(Token)
   openLexer(lex, fileIdx, inputstream, cache, config)
   var prevToken = tkEof
   while tok.tokType != tkEof:
@@ -1418,11 +1367,11 @@ proc getIndentWidth*(fileIdx: FileIndex, inputstream: PLLStream;
 
 proc getPrecedence*(ident: PIdent): int =
   ## assumes ident is binary operator already
-  var tok: Token
-  initToken(tok)
-  tok.ident = ident
-  tok.tokType =
-    if tok.ident.id in ord(tokKeywordLow) - ord(tkSymbol)..ord(tokKeywordHigh) - ord(tkSymbol):
-      TokType(tok.ident.id + ord(tkSymbol))
-    else: tkOpr
+  let
+    tokType =
+      if ident.id in ord(tokKeywordLow) - ord(tkSymbol)..ord(tokKeywordHigh) - ord(tkSymbol):
+        TokType(ident.id + ord(tkSymbol))
+      else: tkOpr
+    tok = Token(ident: ident, tokType: tokType)
+
   getPrecedence(tok)

compiler/liftdestructors.nim

@@ -8,11 +8,12 @@
 #
 
 ## This module implements lifting for type-bound operations
-## (``=sink``, ``=copy``, ``=destroy``, ``=deepCopy``).
+## (`=sink`, `=copy`, `=destroy`, `=deepCopy`, `=wasMoved`, `=dup`).
 
 import modulegraphs, lineinfos, idents, ast, renderer, semdata,
-  sighashes, lowerings, options, types, msgs, magicsys, tables, ccgutils
+  sighashes, lowerings, options, types, msgs, magicsys, ccgutils
 
+import std/tables
 from trees import isCaseObj
 
 when defined(nimPreviewSlimSystem):
@@ -34,11 +35,12 @@ type
 
 template destructor*(t: PType): PSym = getAttachedOp(c.g, t, attachedDestructor)
 template assignment*(t: PType): PSym = getAttachedOp(c.g, t, attachedAsgn)
+template dup*(t: PType): PSym = getAttachedOp(c.g, t, attachedDup)
 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)
@@ -49,15 +51,15 @@ proc at(a, i: PNode, elemType: PType): PNode =
   result[1] = i
   result.typ = elemType
 
-proc destructorOverriden(g: ModuleGraph; t: PType): bool =
+proc destructorOverridden(g: ModuleGraph; t: PType): bool =
   let op = getAttachedOp(g, t, attachedDestructor)
-  op != nil and sfOverriden in op.flags
+  op != nil and sfOverridden in op.flags
 
 proc fillBodyTup(c: var TLiftCtx; t: PType; body, x, y: PNode) =
-  for i in 0..<t.len:
+  for i, a in t.ikids:
     let lit = lowerings.newIntLit(c.g, x.info, i)
-    let b = if c.kind == attachedTrace: y else: y.at(lit, t[i])
-    fillBody(c, t[i], body, x.at(lit, t[i]), b)
+    let b = if c.kind == attachedTrace: y else: y.at(lit, a)
+    fillBody(c, a, body, x.at(lit, a), b)
 
 proc dotField(x: PNode, f: PSym): PNode =
   result = newNodeI(nkDotExpr, x.info, 2)
@@ -82,14 +84,14 @@ proc genBuiltin(c: var TLiftCtx; magic: TMagic; name: string; i: PNode): PNode =
   result = genBuiltin(c.g, c.idgen, magic, name, i)
 
 proc defaultOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
-  if c.kind in {attachedAsgn, attachedDeepCopy, attachedSink}:
+  if c.kind in {attachedAsgn, attachedDeepCopy, attachedSink, attachedDup}:
     body.add newAsgnStmt(x, y)
   elif c.kind == attachedDestructor and c.addMemReset:
     let call = genBuiltin(c, mDefault, "default", x)
     call.typ = t
     body.add newAsgnStmt(x, call)
   elif c.kind == attachedWasMoved:
-    body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+    body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)
 
 proc genAddr(c: var TLiftCtx; x: PNode): PNode =
   if x.kind == nkHiddenDeref:
@@ -137,18 +139,21 @@ proc genContainerOf(c: var TLiftCtx; objType: PType, field, x: PSym): PNode =
   result.add minusExpr
 
 proc destructorCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
-  var destroy = newNodeIT(nkCall, x.info, op.typ[0])
+  var destroy = newNodeIT(nkCall, x.info, op.typ.returnType)
   destroy.add(newSymNode(op))
-  destroy.add genAddr(c, x)
+  if op.typ.firstParamType.kind != tyVar:
+    destroy.add x
+  else:
+    destroy.add genAddr(c, x)
   if sfNeverRaises notin op.flags:
     c.canRaise = true
   if c.addMemReset:
-    result = newTree(nkStmtList, destroy, genBuiltin(c, mWasMoved,  "wasMoved", x))
+    result = newTree(nkStmtList, destroy, genBuiltin(c, mWasMoved,  "`=wasMoved`", x))
   else:
     result = destroy
 
 proc genWasMovedCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
-  result = newNodeIT(nkCall, x.info, op.typ[0])
+  result = newNodeIT(nkCall, x.info, op.typ.returnType)
   result.add(newSymNode(op))
   result.add genAddr(c, x)
 
@@ -158,8 +163,7 @@ 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 f.typ.skipTypes(abstractInst).kind in {tyRef, tyProc} and
-        c.g.config.selectedGC in {gcArc, gcOrc, 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:
@@ -217,15 +221,18 @@ proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool)
     illFormedAstLocal(n, c.g.config)
 
 proc fillBodyObjTImpl(c: var TLiftCtx; t: PType, body, x, y: PNode) =
-  if t.len > 0 and t[0] != nil:
-    fillBody(c, skipTypes(t[0], abstractPtrs), body, x, y)
+  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)
   var obj = t
-  while obj.len > 0 and obj[0] != nil:
-    obj = skipTypes(obj[0], abstractPtrs)
+  while obj.baseClass != nil:
+    obj = skipTypes(obj.baseClass, abstractPtrs)
     hasCase = hasCase or isCaseObj(obj.n)
 
   if hasCase and c.kind in {attachedAsgn, attachedDeepCopy}:
@@ -243,7 +250,7 @@ proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
     # for every field (dependent on dest.kind):
     #   `=` dest.field, src.field
     # =destroy(blob)
-    var dummy = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), nextSymId c.idgen, c.fn, c.info)
+    var dummy = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), c.idgen, c.fn, c.info)
     dummy.typ = y.typ
     if ccgIntroducedPtr(c.g.config, dummy, y.typ):
       # Because of potential aliasing when the src param is passed by ref, we need to check for equality here,
@@ -252,7 +259,7 @@ proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
         newTreeIT(nkAddr, c.info, makePtrType(c.fn, x.typ, c.idgen), x), newTreeIT(nkAddr, c.info, makePtrType(c.fn, y.typ, c.idgen), y))
       cond.typ = getSysType(c.g, x.info, tyBool)
       body.add genIf(c, cond, newTreeI(nkReturnStmt, c.info, newNodeI(nkEmpty, c.info)))
-    var temp = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), nextSymId c.idgen, c.fn, c.info)
+    var temp = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), c.idgen, c.fn, c.info)
     temp.typ = x.typ
     incl(temp.flags, sfFromGeneric)
     var v = newNodeI(nkVarSection, c.info)
@@ -262,7 +269,7 @@ 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
 
@@ -283,8 +290,8 @@ proc boolLit*(g: ModuleGraph; info: TLineInfo; value: bool): PNode =
   result.typ = getSysType(g, info, tyBool)
 
 proc getCycleParam(c: TLiftCtx): PNode =
-  assert c.kind == attachedAsgn
-  if c.fn.typ.len == 4:
+  assert c.kind in {attachedAsgn, attachedDup}
+  if c.fn.typ.len == 3 + ord(c.kind == attachedAsgn):
     result = c.fn.typ.n.lastSon
     assert result.kind == nkSym
     assert result.sym.name.s == "cyclic"
@@ -298,30 +305,41 @@ proc newHookCall(c: var TLiftCtx; op: PSym; x, y: PNode): PNode =
   result.add newSymNode(op)
   if sfNeverRaises notin op.flags:
     c.canRaise = true
-  if op.typ.sons[1].kind == tyVar:
+  if op.typ.firstParamType.kind == tyVar:
     result.add genAddr(c, x)
   else:
     result.add x
   if y != nil:
     result.add y
-  if op.typ.len == 4:
+  if op.typ.signatureLen == 4:
     assert y != nil
-    if c.fn.typ.len == 4:
+    if c.fn.typ.signatureLen == 4:
       result.add getCycleParam(c)
     else:
       # assume the worst: A cycle is created:
       result.add boolLit(c.g, y.info, true)
 
 proc newOpCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
-  result = newNodeIT(nkCall, x.info, op.typ[0])
+  result = newNodeIT(nkCall, x.info, op.typ.returnType)
   result.add(newSymNode(op))
   result.add x
   if sfNeverRaises notin op.flags:
     c.canRaise = true
 
+  if c.kind == attachedDup and op.typ.len == 3:
+    assert x != nil
+    if c.fn.typ.len == 3:
+      result.add getCycleParam(c)
+    else:
+      # assume the worst: A cycle is created:
+      result.add boolLit(c.g, x.info, true)
+
 proc newDeepCopyCall(c: var TLiftCtx; op: PSym; x, y: PNode): PNode =
   result = newAsgnStmt(x, newOpCall(c, op, y))
 
+proc newDupCall(c: var TLiftCtx; op: PSym; x, y: PNode): PNode =
+  result = newAsgnStmt(x, newOpCall(c, op, y))
+
 proc usesBuiltinArc(t: PType): bool =
   proc wrap(t: PType): bool {.nimcall.} = ast.isGCedMem(t)
   result = types.searchTypeFor(t, wrap)
@@ -346,9 +364,9 @@ proc considerAsgnOrSink(c: var TLiftCtx; t: PType; body, x, y: PNode;
                         field: var PSym): bool =
   if optSeqDestructors in c.g.config.globalOptions:
     var op = field
-    let destructorOverriden = destructorOverriden(c.g, t)
+    let destructorOverridden = destructorOverridden(c.g, t)
     if op != nil and op != c.fn and
-        (sfOverriden in op.flags or destructorOverriden):
+        (sfOverridden in op.flags or destructorOverridden):
       if sfError in op.flags:
         incl c.fn.flags, sfError
       #else:
@@ -356,10 +374,12 @@ proc considerAsgnOrSink(c: var TLiftCtx; t: PType; body, x, y: PNode;
       onUse(c.info, op)
       body.add newHookCall(c, op, x, y)
       result = true
-    elif op == nil and destructorOverriden:
+    elif op == nil and destructorOverridden:
       op = produceSym(c.g, c.c, t, c.kind, c.info, c.idgen)
       body.add newHookCall(c, op, x, y)
       result = true
+    else:
+      result = false
   elif tfHasAsgn in t.flags:
     var op: PSym
     if sameType(t, c.asgnForType):
@@ -389,12 +409,14 @@ proc considerAsgnOrSink(c: var TLiftCtx; t: PType; body, x, y: PNode;
     assert op.ast[genericParamsPos].kind == nkEmpty
     body.add newHookCall(c, op, x, y)
     result = true
+  else:
+    result = false
 
 proc addDestructorCall(c: var TLiftCtx; orig: PType; body, x: PNode) =
   let t = orig.skipTypes(abstractInst - {tyDistinct})
   var op = t.destructor
 
-  if op != nil and sfOverriden in op.flags:
+  if op != nil and sfOverridden in op.flags:
     if op.ast.isGenericRoutine:
       # patch generic destructor:
       op = instantiateGeneric(c, op, t, t.typeInst)
@@ -417,7 +439,7 @@ proc considerUserDefinedOp(c: var TLiftCtx; t: PType; body, x, y: PNode): bool =
   case c.kind
   of attachedDestructor:
     var op = t.destructor
-    if op != nil and sfOverriden in op.flags:
+    if op != nil and sfOverridden in op.flags:
 
       if op.ast.isGenericRoutine:
         # patch generic destructor:
@@ -428,10 +450,12 @@ proc considerUserDefinedOp(c: var TLiftCtx; t: PType; body, x, y: PNode): bool =
       onUse(c.info, op)
       body.add destructorCall(c, op, x)
       result = true
+    else:
+      result = false
     #result = addDestructorCall(c, t, body, x)
   of attachedAsgn, attachedSink, attachedTrace:
     var op = getAttachedOp(c.g, t, c.kind)
-    if op != nil and sfOverriden in op.flags:
+    if op != nil and sfOverridden in op.flags:
       if op.ast.isGenericRoutine:
         # patch generic =trace:
         op = instantiateGeneric(c, op, t, t.typeInst)
@@ -448,10 +472,12 @@ proc considerUserDefinedOp(c: var TLiftCtx; t: PType; body, x, y: PNode): bool =
       onUse(c.info, op)
       body.add newDeepCopyCall(c, op, x, y)
       result = true
+    else:
+      result = false
 
   of attachedWasMoved:
     var op = getAttachedOp(c.g, t, attachedWasMoved)
-    if op != nil and sfOverriden in op.flags:
+    if op != nil and sfOverridden in op.flags:
 
       if op.ast.isGenericRoutine:
         # patch generic destructor:
@@ -462,9 +488,27 @@ proc considerUserDefinedOp(c: var TLiftCtx; t: PType; body, x, y: PNode): bool =
       onUse(c.info, op)
       body.add genWasMovedCall(c, op, x)
       result = true
+    else:
+      result = false
+
+  of attachedDup:
+    var op = getAttachedOp(c.g, t, attachedDup)
+    if op != nil and sfOverridden in op.flags:
+
+      if op.ast.isGenericRoutine:
+        # patch generic destructor:
+        op = instantiateGeneric(c, op, t, t.typeInst)
+        setAttachedOp(c.g, c.idgen.module, t, attachedDup, op)
+
+      #markUsed(c.g.config, c.info, op, c.g.usageSym)
+      onUse(c.info, op)
+      body.add newDupCall(c, op, x, y)
+      result = true
+    else:
+      result = false
 
 proc declareCounter(c: var TLiftCtx; body: PNode; first: BiggestInt): PNode =
-  var temp = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), nextSymId(c.idgen), c.fn, c.info)
+  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.flags, sfFromGeneric)
 
@@ -474,7 +518,7 @@ proc declareCounter(c: var TLiftCtx; body: PNode; first: BiggestInt): PNode =
   body.add v
 
 proc declareTempOf(c: var TLiftCtx; body: PNode; value: PNode): PNode =
-  var temp = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), nextSymId(c.idgen), c.fn, c.info)
+  var temp = newSym(skTemp, getIdent(c.g.cache, lowerings.genPrefix), c.idgen, c.fn, c.info)
   temp.typ = value.typ
   incl(temp.flags, sfFromGeneric)
 
@@ -512,7 +556,7 @@ proc forallElements(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   let counterIdx = body.len
   let i = declareCounter(c, body, toInt64(firstOrd(c.g.config, t)))
   let whileLoop = genWhileLoop(c, i, x)
-  let elemType = t.lastSon
+  let elemType = t.elementType
   let b = if c.kind == attachedTrace: y else: y.at(i, elemType)
   fillBody(c, elemType, whileLoop[1], x.at(i, elemType), b)
   if whileLoop[1].len > 0:
@@ -521,14 +565,28 @@ proc forallElements(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   else:
     body.sons.setLen counterIdx
 
+proc checkSelfAssignment(c: var TLiftCtx; t: PType; body, x, y: PNode) =
+  var cond = callCodegenProc(c.g, "sameSeqPayload", c.info,
+      newTreeIT(nkAddr, c.info, makePtrType(c.fn, x.typ, c.idgen), x),
+      newTreeIT(nkAddr, c.info, makePtrType(c.fn, y.typ, c.idgen), y)
+      )
+  cond.typ = getSysType(c.g, c.info, tyBool)
+  body.add genIf(c, cond, newTreeI(nkReturnStmt, c.info, newNodeI(nkEmpty, c.info)))
+
 proc fillSeqOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   case c.kind
+  of attachedDup:
+    body.add setLenSeqCall(c, t, x, y)
+    forallElements(c, t, body, x, y)
   of attachedAsgn, attachedDeepCopy:
     # we generate:
+    # if x.p == y.p:
+    #   return
     # setLen(dest, y.len)
     # var i = 0
     # while i < y.len: dest[i] = y[i]; inc(i)
     # This is usually more efficient than a destroy/create pair.
+    checkSelfAssignment(c, t, body, x, y)
     body.add setLenSeqCall(c, t, x, y)
     forallElements(c, t, body, x, y)
   of attachedSink:
@@ -542,17 +600,17 @@ proc fillSeqOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
     forallElements(c, t, body, x, y)
     body.add genBuiltin(c, mDestroy, "destroy", x)
   of attachedTrace:
-    if canFormAcycle(t.elemType):
+    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)
   # recursions are tricky, so we might need to forward the generated
   # operation here:
   var t = t
-  if t.assignment == nil or t.destructor == nil:
+  if t.assignment == nil or t.destructor == nil or t.dup == nil:
     let h = sighashes.hashType(t,c.g.config, {CoType, CoConsiderOwned, CoDistinct})
     let canon = c.g.canonTypes.getOrDefault(h)
     if canon != nil: t = canon
@@ -578,16 +636,22 @@ proc useSeqOrStrOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
     doAssert t.destructor != nil
     body.add destructorCall(c, t.destructor, x)
   of attachedTrace:
-    if t.kind != tyString and canFormAcycle(t.elemType):
+    if t.kind != tyString and canFormAcycle(c.g, t.elemType):
       let op = getAttachedOp(c.g, t, c.kind)
       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)
+    if op == nil:
+      return # protect from recursion
+    body.add newDupCall(c, op, x, y)
 
 proc fillStrOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   case c.kind
-  of attachedAsgn, attachedDeepCopy:
+  of attachedAsgn, attachedDeepCopy, attachedDup:
     body.add callCodegenProc(c.g, "nimAsgnStrV2", c.info, genAddr(c, x), y)
   of attachedSink:
     let moveCall = genBuiltin(c, mMove, "move", x)
@@ -599,11 +663,11 @@ proc fillStrOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
     body.add genBuiltin(c, mDestroy, "destroy", x)
   of attachedTrace:
     discard "strings are atomic and have no inner elements that are to trace"
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)
 
-proc cyclicType*(t: PType): bool =
+proc cyclicType*(g: ModuleGraph, t: PType): bool =
   case t.kind
-  of tyRef: result = types.canFormAcycle(t.lastSon)
+  of tyRef: result = types.canFormAcycle(g, t.elementType)
   of tyProc: result = t.callConv == ccClosure
   else: result = false
 
@@ -628,10 +692,10 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
 
   ]#
   var actions = newNodeI(nkStmtList, c.info)
-  let elemType = t.lastSon
+  let elemType = t.elementType
 
   createTypeBoundOps(c.g, c.c, elemType, c.info, c.idgen)
-  let isCyclic = c.g.config.selectedGC == gcOrc and types.canFormAcycle(elemType)
+  let isCyclic = c.g.config.selectedGC == gcOrc and types.canFormAcycle(c.g, elemType)
 
   let isInheritableAcyclicRef = c.g.config.selectedGC == gcOrc and
                       (not isPureObject(elemType)) and
@@ -639,7 +703,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   # dynamic Acyclic refs need to use dyn decRef
 
   let tmp =
-    if isCyclic and c.kind in {attachedAsgn, attachedSink}:
+    if isCyclic and c.kind in {attachedAsgn, attachedSink, attachedDup}:
       declareTempOf(c, body, x)
     else:
       x
@@ -698,8 +762,16 @@ 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)
+      body.add genIf(c, y, callCodegenProc(c.g,
+          "nimIncRefCyclic", c.info, y, getCycleParam(c)))
+    else:
+      body.add newAsgnStmt(x, y)
+      body.add genIf(c, y, callCodegenProc(c.g,
+          "nimIncRef", c.info, y))
 
 proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   ## Closures are really like refs except they always use a virtual destructor
@@ -709,7 +781,7 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
 
   let isCyclic = c.g.config.selectedGC == gcOrc
   let tmp =
-    if isCyclic and c.kind in {attachedAsgn, attachedSink}:
+    if isCyclic and c.kind in {attachedAsgn, attachedSink, attachedDup}:
       declareTempOf(c, body, xenv)
     else:
       xenv
@@ -743,12 +815,21 @@ proc atomicClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
 
       body.add genIf(c, cond, actions)
       body.add newAsgnStmt(x, y)
+  of attachedDup:
+    let yenv = genBuiltin(c, mAccessEnv, "accessEnv", y)
+    yenv.typ = getSysType(c.g, c.info, tyPointer)
+    if isCyclic:
+      body.add newAsgnStmt(x, y)
+      body.add genIf(c, yenv, callCodegenProc(c.g, "nimIncRefCyclic", c.info, yenv, getCycleParam(c)))
+    else:
+      body.add newAsgnStmt(x, y)
+      body.add genIf(c, yenv, callCodegenProc(c.g, "nimIncRef", c.info, yenv))
   of attachedDestructor:
     body.add genIf(c, cond, actions)
   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
@@ -761,6 +842,9 @@ proc weakrefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
     body.add genIf(c, y, callCodegenProc(c.g, "nimIncRef", c.info, y))
     body.add genIf(c, x, callCodegenProc(c.g, "nimDecWeakRef", c.info, x))
     body.add newAsgnStmt(x, y)
+  of attachedDup:
+    body.add newAsgnStmt(x, y)
+    body.add genIf(c, y, callCodegenProc(c.g, "nimIncRef", c.info, y))
   of attachedDestructor:
     # it's better to prepend the destruction of weak refs in order to
     # prevent wrong "dangling refs exist" problems:
@@ -773,12 +857,12 @@ proc weakrefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
       body.sons.insert(des, 0)
   of attachedDeepCopy: assert(false, "cannot happen")
   of attachedTrace: discard
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)
 
 proc ownedRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   var actions = newNodeI(nkStmtList, c.info)
 
-  let elemType = t.lastSon
+  let elemType = t.skipModifier
   #fillBody(c, elemType, actions, genDeref(x), genDeref(y))
   #var disposeCall = genBuiltin(c, mDispose, "dispose", x)
 
@@ -795,11 +879,13 @@ proc ownedRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   of attachedSink, attachedAsgn:
     body.add genIf(c, x, actions)
     body.add newAsgnStmt(x, y)
+  of attachedDup:
+    body.add newAsgnStmt(x, y)
   of attachedDestructor:
     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:
@@ -811,7 +897,7 @@ 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, gcOrc}:
+      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
@@ -826,6 +912,11 @@ proc closureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
       body.add genIf(c, yy, callCodegenProc(c.g, "nimIncRef", c.info, yy))
       body.add genIf(c, xx, callCodegenProc(c.g, "nimDecWeakRef", c.info, xx))
       body.add newAsgnStmt(x, y)
+    of attachedDup:
+      let yy = genBuiltin(c, mAccessEnv, "accessEnv", y)
+      yy.typ = getSysType(c.g, c.info, tyPointer)
+      body.add newAsgnStmt(x, y)
+      body.add genIf(c, yy, callCodegenProc(c.g, "nimIncRef", c.info, yy))
     of attachedDestructor:
       let des = genIf(c, xx, callCodegenProc(c.g, "nimDecWeakRef", c.info, xx))
       if body.len == 0:
@@ -834,7 +925,7 @@ 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)
@@ -846,11 +937,13 @@ proc ownedClosureOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   of attachedSink, attachedAsgn:
     body.add genIf(c, xx, actions)
     body.add newAsgnStmt(x, y)
+  of attachedDup:
+    body.add newAsgnStmt(x, y)
   of attachedDestructor:
     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
@@ -859,7 +952,7 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
       tyPtr, tyUncheckedArray, tyVar, tyLent:
     defaultOp(c, t, body, x, y)
   of tyRef:
-    if c.g.config.selectedGC in {gcArc, gcOrc}:
+    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):
@@ -868,7 +961,7 @@ 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}:
+      if c.g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
         atomicClosureOp(c, t, body, x, y)
       else:
         closureOp(c, t, body, x, y)
@@ -914,13 +1007,28 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
       defaultOp(c, t, body, x, y)
   of tyObject:
     if not considerUserDefinedOp(c, t, body, x, y):
-      if c.kind in {attachedAsgn, attachedSink} and t.sym != nil and sfImportc in t.sym.flags:
-        body.add newAsgnStmt(x, y)
+      if t.sym != nil and sfImportc in t.sym.flags:
+        case c.kind
+        of {attachedAsgn, attachedSink, attachedDup}:
+          body.add newAsgnStmt(x, y)
+        of attachedWasMoved:
+          body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)
+        else:
+          fillBodyObjT(c, t, body, x, y)
       else:
-        fillBodyObjT(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):
-      fillBody(c, t[0], body, x, y)
+      fillBody(c, t.elementType, body, x, y)
   of tyTuple:
     fillBodyTup(c, t, body, x, y)
   of tyVarargs, tyOpenArray:
@@ -937,42 +1045,86 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
     discard
   of tyOrdinal, tyRange, tyInferred,
      tyGenericInst, tyAlias, tySink:
-    fillBody(c, lastSon(t), body, x, y)
-  of tyConcept, tyIterable: doAssert false
+    fillBody(c, skipModifier(t), body, x, y)
+  of tyConcept, tyIterable: raiseAssert "unreachable"
 
 proc produceSymDistinctType(g: ModuleGraph; c: PContext; typ: PType;
                             kind: TTypeAttachedOp; info: TLineInfo;
                             idgen: IdGenerator): PSym =
   assert typ.kind == tyDistinct
-  let baseType = typ[0]
+  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)
 
-proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp;
+proc symDupPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp;
               info: TLineInfo; idgen: IdGenerator): PSym =
+  let procname = getIdent(g.cache, AttachedOpToStr[kind])
+  result = newSym(skProc, procname, idgen, owner, info)
+  let res = newSym(skResult, getIdent(g.cache, "result"), idgen, result, info)
+  let src = newSym(skParam, getIdent(g.cache, "src"),
+                   idgen, result, info)
+  res.typ = typ
+  src.typ = typ
+
+  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 == gcOrc and
+    cyclicType(g, typ.skipTypes(abstractInst)):
+    let cycleParam = newSym(skParam, getIdent(g.cache, "cyclic"),
+                            idgen, result, info)
+    cycleParam.typ = getSysType(g, info, tyBool)
+    result.typ.addParam cycleParam
+
+  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] = newNodeI(nkStmtList, info)
+  n[resultPos] = newSymNode(res)
+  result.ast = n
+  incl result.flags, sfFromGeneric
+  incl result.flags, sfGeneratedOp
+
+proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp;
+              info: TLineInfo; idgen: IdGenerator; isDiscriminant = false; isDistinct = false): PSym =
+  if kind == attachedDup:
+    return symDupPrototype(g, typ, owner, kind, info, idgen)
 
   let procname = getIdent(g.cache, AttachedOpToStr[kind])
-  result = newSym(skProc, procname, nextSymId(idgen), owner, info)
-  let dest = newSym(skParam, getIdent(g.cache, "dest"), nextSymId(idgen), result, info)
+  result = newSym(skProc, procname, idgen, owner, info)
+  let dest = newSym(skParam, getIdent(g.cache, "dest"), idgen, result, info)
   let src = newSym(skParam, getIdent(g.cache, if kind == attachedTrace: "env" else: "src"),
-                   nextSymId(idgen), result, info)
-  dest.typ = makeVarType(typ.owner, typ, idgen)
+                   idgen, result, info)
+
+  if kind == attachedDestructor and g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc} and
+     ((g.config.isDefined("nimPreviewNonVarDestructor") and not isDiscriminant) or (typ.kind in {tyRef, tyString, tySequence} and not isDistinct)):
+    dest.typ = typ
+  else:
+    dest.typ = makeVarType(typ.owner, typ, idgen)
+
   if kind == attachedTrace:
     src.typ = getSysType(g, info, tyPointer)
   else:
     src.typ = typ
 
-  result.typ = newProcType(info, nextTypeId(idgen), owner)
+  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 == gcOrc and
-      cyclicType(typ.skipTypes(abstractInst)):
+      cyclicType(g, typ.skipTypes(abstractInst)):
     let cycleParam = newSym(skParam, getIdent(g.cache, "cyclic"),
-                            nextSymId(idgen), result, info)
+                            idgen, result, info)
     cycleParam.typ = getSysType(g, info, tyBool)
     result.typ.addParam cycleParam
 
@@ -984,6 +1136,9 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
   result.ast = n
   incl result.flags, sfFromGeneric
   incl result.flags, sfGeneratedOp
+  if kind == attachedWasMoved:
+    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)
@@ -993,33 +1148,36 @@ 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:
     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)
 
-  let dest = result.typ.n[1].sym
-  let d = newDeref(newSymNode(dest))
-  let src = if kind in {attachedDestructor, attachedWasMoved}: newNodeIT(nkSym, info, getSysType(g, info, tyPointer))
+  let dest = if kind == attachedDup: result.ast[resultPos].sym else: result.typ.n[1].sym
+  let d = if result.typ.firstParamType.kind == tyVar: newDeref(newSymNode(dest)) else: newSymNode(dest)
+  let src = case kind
+            of {attachedDestructor, attachedWasMoved}: newNodeIT(nkSym, info, getSysType(g, info, tyPointer))
+            of attachedDup: newSymNode(result.typ.n[1].sym)
             else: newSymNode(result.typ.n[2].sym)
 
   # register this operation already:
   setAttachedOpPartial(g, idgen.module, typ, kind, result)
 
-  if kind == attachedSink and destructorOverriden(g, typ):
+  if kind == attachedSink and destructorOverridden(g, typ):
     ## compiler can use a combination of `=destroy` and memCopy for sink op
     dest.flags.incl sfCursor
-    result.ast[bodyPos].add newOpCall(a, getAttachedOp(g, typ, attachedDestructor), d[0])
+    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
-    if g.config.selectedGC in {gcArc, gcOrc, gcHooks}:
+    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
@@ -1030,18 +1188,24 @@ proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
       fillStrOp(a, typ, result.ast[bodyPos], d, src)
     else:
       fillBody(a, typ, result.ast[bodyPos], d, src)
-      if tk == tyObject and a.kind in {attachedAsgn, attachedSink, attachedDeepCopy} and not lacksMTypeField(typ):
+      if tk == tyObject and a.kind in {attachedAsgn, attachedSink, attachedDeepCopy, attachedDup} and not lacksMTypeField(typ):
         # bug #19205: Do not forget to also copy the hidden type field:
         genTypeFieldCopy(a, typ, result.ast[bodyPos], d, src)
 
-  if not a.canRaise: incl result.flags, sfNeverRaises
+  if not a.canRaise:
+    incl result.flags, sfNeverRaises
+    result.ast[pragmasPos] = newNodeI(nkPragma, info)
+    result.ast[pragmasPos].add newTree(nkExprColonExpr,
+        newIdentNode(g.cache.getIdent("raises"),  info), newNodeI(nkBracket, info))
+
   completePartialOp(g, idgen.module, typ, kind, result)
 
 
 proc produceDestructorForDiscriminator*(g: ModuleGraph; typ: PType; field: PSym,
                                         info: TLineInfo; idgen: IdGenerator): PSym =
   assert(typ.skipTypes({tyAlias, tyGenericInst}).kind == tyObject)
-  result = symPrototype(g, field.typ, typ.owner, attachedDestructor, info, idgen)
+  # 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)
   var a = TLiftCtx(info: info, g: g, kind: attachedDestructor, asgnForType: typ, idgen: idgen,
                    fn: result)
   a.asgnForType = typ
@@ -1049,7 +1213,7 @@ proc produceDestructorForDiscriminator*(g: ModuleGraph; typ: PType; field: PSym,
   a.addMemReset = true
   let discrimantDest = result.typ.n[1].sym
 
-  let dst = newSym(skVar, getIdent(g.cache, "dest"), nextSymId(idgen), result, info)
+  let dst = newSym(skVar, getIdent(g.cache, "dest"), idgen, result, info)
   dst.typ = makePtrType(typ.owner, typ, idgen)
   let dstSym = newSymNode(dst)
   let d = newDeref(dstSym)
@@ -1075,7 +1239,7 @@ proc patchBody(g: ModuleGraph; c: PContext; n: PNode; info: TLineInfo; idgen: Id
       if op != nil:
         if op.ast.isGenericRoutine:
           internalError(g.config, info, "resolved destructor is generic")
-        if op.magic == mDestroy:
+        if op.magic == mDestroy and t.kind != tyString:
           internalError(g.config, info, "patching mDestroy with mDestroy?")
         n[0] = newSymNode(op)
   for x in n: patchBody(g, c, x, info, idgen)
@@ -1093,7 +1257,7 @@ proc inst(g: ModuleGraph; c: PContext; t: PType; kind: TTypeAttachedOp; idgen: I
     else:
       localError(g.config, info, "unresolved generic parameter")
 
-proc isTrival(s: PSym): bool {.inline.} =
+proc isTrival*(s: PSym): bool {.inline.} =
   s == nil or (s.ast != nil and s.ast[bodyPos].len == 0)
 
 proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInfo;
@@ -1128,7 +1292,7 @@ proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInf
   # 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: 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]:

compiler/liftlocals.nim

@@ -10,9 +10,11 @@
 ## This module implements the '.liftLocals' pragma.
 
 import
-  strutils, options, ast, msgs,
+  options, ast, msgs,
   idents, renderer, types, lowerings, lineinfos
 
+import std/strutils
+
 from pragmas import getPragmaVal
 from wordrecg import wLiftLocals
 
@@ -49,6 +51,7 @@ proc liftLocals(n: PNode; i: int; c: var Ctx) =
       liftLocals(it, i, c)
 
 proc lookupParam(params, dest: PNode): PSym =
+  result = nil
   if dest.kind != nkIdent: return nil
   for i in 1..<params.len:
     if params[i].kind == nkSym and params[i].sym.name.id == dest.ident.id:

compiler/lineinfos.nim

@@ -7,10 +7,11 @@
 #    distribution, for details about the copyright.
 #
 
-## This module contains the ``TMsgKind`` enum as well as the
-## ``TLineInfo`` object.
+## This module contains the `TMsgKind` enum as well as the
+## `TLineInfo` object.
 
-import ropes, tables, pathutils, hashes
+import ropes, pathutils
+import std/[hashes, tables]
 
 const
   explanationsBaseUrl* = "https://nim-lang.github.io/Nim"
@@ -44,6 +45,7 @@ type
     errRstSandboxedDirective,
     errProveInit, # deadcode
     errGenerated,
+    errFailedMove,
     errUser,
     # warnings
     warnCannotOpenFile = "CannotOpenFile", warnOctalEscape = "OctalEscape",
@@ -83,16 +85,20 @@ type
     warnCstringConv = "CStringConv",
     warnPtrToCstringConv = "PtrToCstringConv",
     warnEffect = "Effect",
-    warnCastSizes = "CastSizes"
+    warnCastSizes = "CastSizes", # deadcode
+    warnAboveMaxSizeSet = "AboveMaxSizeSet",
     warnImplicitTemplateRedefinition = "ImplicitTemplateRedefinition",
     warnUnnamedBreak = "UnnamedBreak",
     warnStmtListLambda = "StmtListLambda",
     warnBareExcept = "BareExcept",
+    warnImplicitDefaultValue = "ImplicitDefaultValue",
+    warnGenericsIgnoredInjection = "GenericsIgnoredInjection",
+    warnStdPrefix = "StdPrefix"
     warnUser = "User",
+    warnGlobalVarConstructorTemporary = "GlobalVarConstructorTemporary",
     # hints
     hintSuccess = "Success", hintSuccessX = "SuccessX",
     hintCC = "CC",
-    hintLineTooLong = "LineTooLong",
     hintXDeclaredButNotUsed = "XDeclaredButNotUsed", hintDuplicateModuleImport = "DuplicateModuleImport",
     hintXCannotRaiseY = "XCannotRaiseY", hintConvToBaseNotNeeded = "ConvToBaseNotNeeded",
     hintConvFromXtoItselfNotNeeded = "ConvFromXtoItselfNotNeeded", hintExprAlwaysX = "ExprAlwaysX",
@@ -102,10 +108,10 @@ type
     hintPattern = "Pattern", hintExecuting = "Exec", hintLinking = "Link", hintDependency = "Dependency",
     hintSource = "Source", hintPerformance = "Performance", hintStackTrace = "StackTrace",
     hintGCStats = "GCStats", hintGlobalVar = "GlobalVar", hintExpandMacro = "ExpandMacro",
-    hintAmbiguousEnum = "AmbiguousEnum",
     hintUser = "User", hintUserRaw = "UserRaw", hintExtendedContext = "ExtendedContext",
     hintMsgOrigin = "MsgOrigin", # since 1.3.5
     hintDeclaredLoc = "DeclaredLoc", # since 1.5.1
+    hintUnknownHint = "UnknownHint"
 
 const
   MsgKindToStr*: array[TMsgKind, string] = [
@@ -127,6 +133,7 @@ const
     errRstSandboxedDirective: "disabled directive: '$1'",
     errProveInit: "Cannot prove that '$1' is initialized.",  # deadcode
     errGenerated: "$1",
+    errFailedMove: "$1",
     errUser: "$1",
     warnCannotOpenFile: "cannot open '$1'",
     warnOctalEscape: "octal escape sequences do not exist; leading zero is ignored",
@@ -182,19 +189,23 @@ const
     warnAnyEnumConv: "$1",
     warnHoleEnumConv: "$1",
     warnCstringConv: "$1",
-    warnPtrToCstringConv: "unsafe conversion to 'cstring' from '$1'; this will become a compile time error in the future",
+    warnPtrToCstringConv: "unsafe conversion to 'cstring' from '$1'; Use a `cast` operation like `cast[cstring](x)`; this will become a compile time error in the future",
     warnEffect: "$1",
-    warnCastSizes: "$1",
+    warnCastSizes: "$1", # deadcode
+    warnAboveMaxSizeSet: "$1",
     warnImplicitTemplateRedefinition: "template '$1' is implicitly redefined; this is deprecated, add an explicit .redefine pragma",
     warnUnnamedBreak: "Using an unnamed break in a block is deprecated; Use a named block with a named break instead",
     warnStmtListLambda: "statement list expression assumed to be anonymous proc; this is deprecated, use `do (): ...` or `proc () = ...` instead",
     warnBareExcept: "$1",
+    warnImplicitDefaultValue: "$1",
+    warnGenericsIgnoredInjection: "$1",
+    warnStdPrefix: "$1 needs the 'std' prefix",
     warnUser: "$1",
+    warnGlobalVarConstructorTemporary: "global variable '$1' initialization requires a temporary variable",
     hintSuccess: "operation successful: $#",
     # keep in sync with `testament.isSuccess`
     hintSuccessX: "$build\n$loc lines; ${sec}s; $mem; proj: $project; out: $output",
     hintCC: "CC: $1",
-    hintLineTooLong: "line too long",
     hintXDeclaredButNotUsed: "'$1' is declared but not used",
     hintDuplicateModuleImport: "$1",
     hintXCannotRaiseY: "$1",
@@ -221,12 +232,12 @@ const
     hintGCStats: "$1",
     hintGlobalVar: "global variable declared here",
     hintExpandMacro: "expanded macro: $1",
-    hintAmbiguousEnum: "$1",
     hintUser: "$1",
     hintUserRaw: "$1",
     hintExtendedContext: "$1",
     hintMsgOrigin: "$1",
     hintDeclaredLoc: "$1",
+    hintUnknownHint: "unknown hint: $1"
   ]
 
 const
@@ -244,7 +255,8 @@ type
   TNoteKinds* = set[TNoteKind]
 
 proc computeNotesVerbosity(): array[0..3, TNoteKinds] =
-  result[3] = {low(TNoteKind)..high(TNoteKind)} - {warnObservableStores, warnResultUsed, warnAnyEnumConv}
+  result = default(array[0..3, TNoteKinds])
+  result[3] = {low(TNoteKind)..high(TNoteKind)} - {warnObservableStores, warnResultUsed, warnAnyEnumConv, warnBareExcept, warnStdPrefix}
   result[2] = result[3] - {hintStackTrace, hintExtendedContext, hintDeclaredLoc, hintProcessingStmt}
   result[1] = result[2] - {warnProveField, warnProveIndex,
     warnGcUnsafe, hintPath, hintDependency, hintCodeBegin, hintCodeEnd,
@@ -275,7 +287,7 @@ type
                                # and parsed; usually "" but is used
                                # for 'nimsuggest'
     hash*: string              # the checksum of the file
-    dirty*: bool               # for 'nimfix' / 'nimpretty' like tooling
+    dirty*: bool               # for 'nimpretty' like tooling
     when defined(nimpretty):
       fullContent*: string
   FileIndex* = distinct int32
@@ -306,7 +318,7 @@ proc `==`*(a, b: FileIndex): bool {.borrow.}
 proc hash*(i: TLineInfo): Hash =
   hash (i.line.int, i.col.int, i.fileIndex.int)
 
-proc raiseRecoverableError*(msg: string) {.noinline.} =
+proc raiseRecoverableError*(msg: string) {.noinline, noreturn.} =
   raise newException(ERecoverableError, msg)
 
 const
@@ -337,9 +349,8 @@ type
 
 
 proc initMsgConfig*(): MsgConfig =
-  result.msgContext = @[]
-  result.lastError = unknownLineInfo
-  result.filenameToIndexTbl = initTable[string, FileIndex]()
-  result.fileInfos = @[]
-  result.errorOutputs = {eStdOut, eStdErr}
+  result = MsgConfig(msgContext: @[], lastError: unknownLineInfo,
+                     filenameToIndexTbl: initTable[string, FileIndex](),
+                     fileInfos: @[], errorOutputs: {eStdOut, eStdErr}
+  )
   result.filenameToIndexTbl["???"] = FileIndex(-1)

compiler/linter.nim

@@ -19,10 +19,12 @@ const
   Letters* = {'a'..'z', 'A'..'Z', '0'..'9', '\x80'..'\xFF', '_'}
 
 proc identLen*(line: string, start: int): int =
+  result = 0
   while start+result < line.len and line[start+result] in Letters:
     inc result
 
 proc `=~`(s: string, a: openArray[string]): bool =
+  result = false
   for x in a:
     if s.startsWith(x): return true
 
@@ -95,7 +97,7 @@ template styleCheckDef*(ctx: PContext; info: TLineInfo; sym: PSym; k: TSymKind)
   if optStyleCheck in ctx.config.options and # ignore if styleChecks are off
      {optStyleHint, optStyleError} * ctx.config.globalOptions != {} and # check only if hint/error is enabled
      hintName in ctx.config.notes and # ignore if name checks are not requested
-     ctx.config.belongsToProjectPackage(ctx.module) 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
@@ -136,7 +138,7 @@ template styleCheckUse*(ctx: PContext; info: TLineInfo; sym: PSym) =
   ## Check symbol uses match their definition's style.
   if {optStyleHint, optStyleError} * ctx.config.globalOptions != {} and # ignore if styleChecks are off
      hintName in ctx.config.notes and # ignore if name checks are not requested
-     ctx.config.belongsToProjectPackage(ctx.module) 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
@@ -147,6 +149,10 @@ proc checkPragmaUseImpl(conf: ConfigRef; info: TLineInfo; w: TSpecialWord; pragm
   if pragmaName != wanted:
     lintReport(conf, info, wanted, pragmaName)
 
-template checkPragmaUse*(conf: ConfigRef; info: TLineInfo; w: TSpecialWord; pragmaName: string) =
-  if {optStyleHint, optStyleError} * conf.globalOptions != {}:
-    checkPragmaUseImpl(conf, info, w, pragmaName)
+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} * ctx.config.globalOptions != {} and # ignore if styleChecks are off
+     hintName in ctx.config.notes and # ignore if name checks are not requested
+     (sym != nil and ctx.config.belongsToProjectPackage(sym)): # ignore foreign packages
+    checkPragmaUseImpl(ctx.config, info, w, pragmaName)

compiler/llstream.nim

@@ -19,7 +19,7 @@ when defined(nimPreviewSlimSystem):
 const hasRstdin = (defined(nimUseLinenoise) or defined(useLinenoise) or defined(useGnuReadline)) and
   not defined(windows)
 
-when hasRstdin: import rdstdin
+when hasRstdin: import std/rdstdin
 
 type
   TLLRepl* = proc (s: PLLStream, buf: pointer, bufLen: int): int
@@ -40,33 +40,22 @@ type
 
   PLLStream* = ref TLLStream
 
-proc llStreamOpen*(data: string): PLLStream =
-  new(result)
-  result.s = data
-  result.kind = llsString
+proc llStreamOpen*(data: sink string): PLLStream =
+  PLLStream(kind: llsString, s: data)
 
 proc llStreamOpen*(f: File): PLLStream =
-  new(result)
-  result.f = f
-  result.kind = llsFile
+  PLLStream(kind: llsFile, f: f)
 
 proc llStreamOpen*(filename: AbsoluteFile, mode: FileMode): PLLStream =
-  new(result)
-  result.kind = llsFile
+  result = PLLStream(kind: llsFile)
   if not open(result.f, filename.string, mode): result = nil
 
 proc llStreamOpen*(): PLLStream =
-  new(result)
-  result.kind = llsNone
+  PLLStream(kind: llsNone)
 
 proc llReadFromStdin(s: PLLStream, buf: pointer, bufLen: int): int
 proc llStreamOpenStdIn*(r: TLLRepl = llReadFromStdin, onPrompt: OnPrompt = nil): PLLStream =
-  new(result)
-  result.kind = llsStdIn
-  result.s = ""
-  result.lineOffset = -1
-  result.repl = r
-  result.onPrompt = onPrompt
+  PLLStream(kind: llsStdIn, s: "", lineOffset: -1, repl: r, onPrompt: onPrompt)
 
 proc llStreamClose*(s: PLLStream) =
   case s.kind
@@ -89,6 +78,8 @@ proc endsWith*(x: string, s: set[char]): bool =
   while i >= 0 and x[i] == ' ': dec(i)
   if i >= 0 and x[i] in s:
     result = true
+  else:
+    result = false
 
 const
   LineContinuationOprs = {'+', '-', '*', '/', '\\', '<', '>', '!', '?', '^',
@@ -104,6 +95,7 @@ proc continueLine(line: string, inTripleString: bool): bool {.inline.} =
         line.endsWith(LineContinuationOprs+AdditionalLineContinuationOprs))
 
 proc countTriples(s: string): int =
+  result = 0
   var i = 0
   while i+2 < s.len:
     if s[i] == '"' and s[i+1] == '"' and s[i+2] == '"':

compiler/lookups.nim

@@ -8,14 +8,16 @@
 #
 
 # This module implements lookup helpers.
-import std/[algorithm, strutils]
+import std/[algorithm, strutils, tables]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
 import
-  intsets, ast, astalgo, idents, semdata, types, msgs, options,
-  renderer, nimfix/prettybase, lineinfos, modulegraphs, astmsgs, sets
+  ast, astalgo, idents, semdata, types, msgs, options,
+  renderer, lineinfos, modulegraphs, astmsgs, wordrecg
+
+import std/[intsets, sets]
 
 proc ensureNoMissingOrUnusedSymbols(c: PContext; scope: PScope)
 
@@ -72,7 +74,7 @@ proc addUniqueSym*(scope: PScope, s: PSym): PSym =
 
 proc openScope*(c: PContext): PScope {.discardable.} =
   result = PScope(parent: c.currentScope,
-                  symbols: newStrTable(),
+                  symbols: initStrTable(),
                   depthLevel: c.scopeDepth + 1)
   c.currentScope = result
 
@@ -94,17 +96,6 @@ iterator localScopesFrom*(c: PContext; scope: PScope): PScope =
     if s == c.topLevelScope: break
     yield s
 
-proc skipAlias*(s: PSym; n: PNode; conf: ConfigRef): PSym =
-  if s == nil or s.kind != skAlias:
-    result = s
-  else:
-    result = s.owner
-    if conf.cmd == cmdNimfix:
-      prettybase.replaceDeprecated(conf, n.info, s, result)
-    else:
-      message(conf, n.info, warnDeprecated, "use " & result.name.s & " instead; " &
-              s.name.s & " is deprecated")
-
 proc isShadowScope*(s: PScope): bool {.inline.} =
   s.parent != nil and s.parent.depthLevel == s.depthLevel
 
@@ -146,7 +137,7 @@ proc nextIdentIter(ti: var ModuleIter; marked: var IntSet; im: ImportedModule;
         return result
 
 iterator symbols(im: ImportedModule; marked: var IntSet; name: PIdent; g: ModuleGraph): PSym =
-  var ti: ModuleIter
+  var ti: ModuleIter = default(ModuleIter)
   var candidate = initIdentIter(ti, marked, im, name, g)
   while candidate != nil:
     yield candidate
@@ -159,7 +150,7 @@ iterator importedItems*(c: PContext; name: PIdent): PSym =
       yield s
 
 proc allPureEnumFields(c: PContext; name: PIdent): seq[PSym] =
-  var ti: TIdentIter
+  var ti: TIdentIter = default(TIdentIter)
   result = @[]
   var res = initIdentIter(ti, c.pureEnumFields, name)
   while res != nil:
@@ -231,7 +222,7 @@ proc debugScopes*(c: PContext; limit=0, max = int.high) {.deprecated.} =
 proc searchInScopesAllCandidatesFilterBy*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSym] =
   result = @[]
   for scope in allScopes(c.currentScope):
-    var ti: TIdentIter
+    var ti: TIdentIter = default(TIdentIter)
     var candidate = initIdentIter(ti, scope.symbols, s)
     while candidate != nil:
       if candidate.kind in filter:
@@ -249,7 +240,7 @@ proc searchInScopesFilterBy*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSy
   result = @[]
   block outer:
     for scope in allScopes(c.currentScope):
-      var ti: TIdentIter
+      var ti: TIdentIter = default(TIdentIter)
       var candidate = initIdentIter(ti, scope.symbols, s)
       while candidate != nil:
         if candidate.kind in filter:
@@ -265,8 +256,63 @@ proc searchInScopesFilterBy*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSy
         if s.kind in filter:
           result.add s
 
-proc errorSym*(c: PContext, n: PNode): PSym =
+proc cmpScopes*(ctx: PContext, s: PSym): int =
+  # Do not return a negative number
+  if s.originatingModule == ctx.module:
+    result = 2
+    var owner = s
+    while true:
+      owner = owner.skipGenericOwner
+      if owner.kind == skModule: break
+      inc result
+  else:
+    result = 1
+
+proc isAmbiguous*(c: PContext, s: PIdent, filter: TSymKinds, sym: var PSym): bool =
+  result = false
+  block outer:
+    for scope in allScopes(c.currentScope):
+      var ti: TIdentIter = default(TIdentIter)
+      var candidate = initIdentIter(ti, scope.symbols, s)
+      var scopeHasCandidate = false
+      while candidate != nil:
+        if candidate.kind in filter:
+          if scopeHasCandidate:
+            # 2 candidates in same scope, ambiguous
+            return true
+          else:
+            scopeHasCandidate = true
+            sym = candidate
+        candidate = nextIdentIter(ti, scope.symbols)
+      if scopeHasCandidate:
+        # scope had a candidate but wasn't ambiguous
+        return false
+
+  var importsHaveCandidate = false
+  var marked = initIntSet()
+  for im in c.imports.mitems:
+    for s in symbols(im, marked, s, c.graph):
+      if s.kind in filter:
+        if importsHaveCandidate:
+          # 2 candidates among imports, ambiguous
+          return true
+        else:
+          importsHaveCandidate = true
+          sym = s
+  if importsHaveCandidate:
+    # imports had a candidate but wasn't ambiguous
+    return false
+
+proc errorSym*(c: PContext, ident: PIdent, info: TLineInfo): PSym =
   ## creates an error symbol to avoid cascading errors (for IDE support)
+  result = newSym(skError, ident, c.idgen, getCurrOwner(c), info, {})
+  result.typ = errorType(c)
+  incl(result.flags, sfDiscardable)
+  # pretend it's from the top level scope to prevent cascading errors:
+  if c.config.cmd != cmdInteractive and c.compilesContextId == 0:
+    c.moduleScope.addSym(result)
+
+proc errorSym*(c: PContext, n: PNode): PSym =
   var m = n
   # ensure that 'considerQuotedIdent' can't fail:
   if m.kind == nkDotExpr: m = m[1]
@@ -274,12 +320,7 @@ proc errorSym*(c: PContext, n: PNode): PSym =
       considerQuotedIdent(c, m)
     else:
       getIdent(c.cache, "err:" & renderTree(m))
-  result = newSym(skError, ident, nextSymId(c.idgen), getCurrOwner(c), n.info, {})
-  result.typ = errorType(c)
-  incl(result.flags, sfDiscardable)
-  # pretend it's from the top level scope to prevent cascading errors:
-  if c.config.cmd != cmdInteractive and c.compilesContextId == 0:
-    c.moduleScope.addSym(result)
+  result = errorSym(c, ident, n.info)
 
 type
   TOverloadIterMode* = enum
@@ -306,10 +347,10 @@ proc getSymRepr*(conf: ConfigRef; s: PSym, getDeclarationPath = true): string =
 
 proc ensureNoMissingOrUnusedSymbols(c: PContext; scope: PScope) =
   # check if all symbols have been used and defined:
-  var it: TTabIter
+  var it: TTabIter = default(TTabIter)
   var s = initTabIter(it, scope.symbols)
   var missingImpls = 0
-  var unusedSyms: seq[tuple[sym: PSym, key: string]]
+  var unusedSyms: seq[tuple[sym: PSym, key: string]] = @[]
   while s != nil:
     if sfForward in s.flags and s.kind notin {skType, skModule}:
       # too many 'implementation of X' errors are annoying
@@ -340,17 +381,18 @@ proc wrongRedefinition*(c: PContext; info: TLineInfo, s: string;
 # xxx pending bootstrap >= 1.4, replace all those overloads with a single one:
 # proc addDecl*(c: PContext, sym: PSym, info = sym.info, scope = c.currentScope) {.inline.} =
 proc addDeclAt*(c: PContext; scope: PScope, sym: PSym, info: TLineInfo) =
-  if sym.name.s == "_": return
+  if sym.name.id == ord(wUnderscore): return
   let conflict = scope.addUniqueSym(sym)
   if conflict != nil:
-    if sym.kind == skModule and conflict.kind == skModule and
-                        sym.position == conflict.position:
+    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.
-      localError(c.config, info, hintDuplicateModuleImport,
-        "duplicate import of '$1'; previous import here: $2" %
-        [sym.name.s, c.config $ conflict.info])
+      if c.importModuleMap[sym.id] == c.importModuleMap[conflict.id]:
+        #only hints if the conflict is the actual module not just a shared name
+        localError(c.config, info, hintDuplicateModuleImport,
+          "duplicate import of '$1'; previous import here: $2" %
+          [sym.name.s, c.config $ conflict.info])
     else:
       wrongRedefinition(c, info, sym.name.s, conflict.info, errGenerated)
 
@@ -396,11 +438,12 @@ proc addOverloadableSymAt*(c: PContext; scope: PScope, fn: PSym) =
   if fn.kind notin OverloadableSyms:
     internalError(c.config, fn.info, "addOverloadableSymAt")
     return
-  let check = strTableGet(scope.symbols, fn.name)
-  if check != nil and check.kind notin OverloadableSyms:
-    wrongRedefinition(c, fn.info, fn.name.s, check.info)
-  else:
-    scope.addSym(fn)
+  if fn.name.id != ord(wUnderscore):
+    let check = strTableGet(scope.symbols, fn.name)
+    if check != nil and check.kind notin OverloadableSyms:
+      wrongRedefinition(c, fn.info, fn.name.s, check.info)
+    else:
+      scope.addSym(fn)
 
 proc addInterfaceOverloadableSymAt*(c: PContext, scope: PScope, sym: PSym) =
   ## adds an overloadable symbol on the scope and the interface if appropriate
@@ -413,7 +456,7 @@ proc openShadowScope*(c: PContext) =
   ## opens a shadow scope, just like any other scope except the depth is the
   ## same as the parent -- see `isShadowScope`.
   c.currentScope = PScope(parent: c.currentScope,
-                          symbols: newStrTable(),
+                          symbols: initStrTable(),
                           depthLevel: c.scopeDepth)
 
 proc closeShadowScope*(c: PContext) =
@@ -437,15 +480,8 @@ proc mergeShadowScope*(c: PContext) =
     else:
       c.addInterfaceDecl(sym)
 
-when false:
-  # `nimfix` used to call `altSpelling` and prettybase.replaceDeprecated(n.info, ident, alt)
-  proc altSpelling(c: PContext, x: PIdent): PIdent =
-    case x.s[0]
-    of 'A'..'Z': result = getIdent(c.cache, toLowerAscii(x.s[0]) & x.s.substr(1))
-    of 'a'..'z': result = getIdent(c.cache, toLowerAscii(x.s[0]) & x.s.substr(1))
-    else: result = x
 
-import std/editdistance, heapqueue
+import std/[editdistance, heapqueue]
 
 type SpellCandidate = object
   dist: int
@@ -466,7 +502,7 @@ proc mustFixSpelling(c: PContext): bool {.inline.} =
   result = c.config.spellSuggestMax != 0 and c.compilesContextId == 0
     # don't slowdown inside compiles()
 
-proc fixSpelling(c: PContext, n: PNode, ident: PIdent, result: var string) =
+proc fixSpelling(c: PContext, ident: PIdent, result: var string) =
   ## when we cannot find the identifier, suggest nearby spellings
   var list = initHeapQueue[SpellCandidate]()
   let name0 = ident.s.nimIdentNormalize
@@ -474,7 +510,7 @@ proc fixSpelling(c: PContext, n: PNode, ident: PIdent, result: var string) =
   for (sym, depth, isLocal) in allSyms(c):
     let depth = -depth - 1
     let dist = editDistance(name0, sym.name.s.nimIdentNormalize)
-    var msg: string
+    var msg: string = ""
     msg.add "\n ($1, $2): '$3'" % [$dist, $depth, sym.name.s]
     list.push SpellCandidate(dist: dist, depth: depth, msg: msg, sym: sym)
 
@@ -489,12 +525,9 @@ proc fixSpelling(c: PContext, n: PNode, ident: PIdent, result: var string) =
     let e = list.pop()
     if c.config.spellSuggestMax == spellSuggestSecretSauce:
       const
-        smallThres = 2
-        maxCountForSmall = 4
-        # avoids ton of operator matches when mis-matching short symbols such as `i`
-        # other heuristics could be devised, such as only suggesting operators if `name0`
-        # is an operator (likewise with non-operators).
-      if e.dist > e0.dist or (name0.len <= smallThres and count >= maxCountForSmall): break
+        minLengthForSuggestion = 4
+        maxCount = 3 # avoids ton of matches; three counts for equal distances
+      if e.dist > e0.dist or count >= maxCount or name0.len < minLengthForSuggestion: break
     elif count >= c.config.spellSuggestMax: break
     if count == 0:
       result.add "\ncandidates (edit distance, scope distance); see '--spellSuggest': "
@@ -507,6 +540,7 @@ proc errorUseQualifier(c: PContext; info: TLineInfo; s: PSym; amb: var bool): PS
   var err = "ambiguous identifier: '" & s.name.s & "'"
   var i = 0
   var ignoredModules = 0
+  result = nil
   for candidate in importedItems(c, s.name):
     if i == 0: err.add " -- use one of the following:\n"
     else: err.add "\n"
@@ -524,10 +558,10 @@ proc errorUseQualifier(c: PContext; info: TLineInfo; s: PSym; amb: var bool): PS
     amb = false
 
 proc errorUseQualifier*(c: PContext; info: TLineInfo; s: PSym) =
-  var amb: bool
+  var amb: bool = false
   discard errorUseQualifier(c, info, s, amb)
 
-proc errorUseQualifier(c: PContext; info: TLineInfo; candidates: seq[PSym]; prefix = "use one of") =
+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:
@@ -546,36 +580,44 @@ proc errorUseQualifier*(c: PContext; info:TLineInfo; choices: PNode) =
   errorUseQualifier(c, info, candidates, prefix)
 
 proc errorUndeclaredIdentifier*(c: PContext; info: TLineInfo; name: string, extra = "") =
-  var err = "undeclared identifier: '" & name & "'" & extra
-  if c.recursiveDep.len > 0:
-    err.add "\nThis might be caused by a recursive module dependency:\n"
-    err.add c.recursiveDep
-    # prevent excessive errors for 'nim check'
-    c.recursiveDep = ""
+  var err: string
+  if name == "_":
+    err = "the special identifier '_' is ignored in declarations and cannot be used"
+  else:
+    err = "undeclared identifier: '" & name & "'"
+    if "`gensym" in name:
+      err.add "; if declared in a template, this identifier may be inconsistently marked inject or gensym"
+    if extra.len != 0:
+      err.add extra
+    if c.recursiveDep.len > 0:
+      err.add "\nThis might be caused by a recursive module dependency:\n"
+      err.add c.recursiveDep
+      # prevent excessive errors for 'nim check'
+      c.recursiveDep = ""
   localError(c.config, info, errGenerated, err)
 
-proc errorUndeclaredIdentifierHint*(c: PContext; n: PNode, ident: PIdent): PSym =
+proc errorUndeclaredIdentifierHint*(c: PContext; ident: PIdent; info: TLineInfo): PSym =
   var extra = ""
-  if c.mustFixSpelling: fixSpelling(c, n, ident, extra)
-  errorUndeclaredIdentifier(c, n.info, ident.s, extra)
-  result = errorSym(c, n)
+  if c.mustFixSpelling: fixSpelling(c, ident, extra)
+  errorUndeclaredIdentifier(c, info, ident.s, extra)
+  result = errorSym(c, ident, info)
 
 proc lookUp*(c: PContext, n: PNode): PSym =
   # Looks up a symbol. Generates an error in case of nil.
   var amb = false
   case n.kind
   of nkIdent:
-    result = searchInScopes(c, n.ident, amb).skipAlias(n, c.config)
-    if result == nil: result = errorUndeclaredIdentifierHint(c, n, n.ident)
+    result = searchInScopes(c, n.ident, amb)
+    if result == nil: result = errorUndeclaredIdentifierHint(c, n.ident, n.info)
   of nkSym:
     result = n.sym
   of nkAccQuoted:
     var ident = considerQuotedIdent(c, n)
-    result = searchInScopes(c, ident, amb).skipAlias(n, c.config)
-    if result == nil: result = errorUndeclaredIdentifierHint(c, n, ident)
+    result = searchInScopes(c, ident, amb)
+    if result == nil: result = errorUndeclaredIdentifierHint(c, ident, n.info)
   else:
     internalError(c.config, n.info, "lookUp")
-    return
+    return nil
   if amb:
     #contains(c.ambiguousSymbols, result.id):
     result = errorUseQualifier(c, n.info, result, amb)
@@ -586,31 +628,38 @@ type
   TLookupFlag* = enum
     checkAmbiguity, checkUndeclared, checkModule, checkPureEnumFields
 
+const allExceptModule = {low(TSymKind)..high(TSymKind)} - {skModule, skPackage}
+
+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 =
-  const allExceptModule = {low(TSymKind)..high(TSymKind)} - {skModule, skPackage}
   case n.kind
   of nkIdent, nkAccQuoted:
     var amb = false
     var ident = considerQuotedIdent(c, n)
     if checkModule in flags:
-      result = searchInScopes(c, ident, amb).skipAlias(n, c.config)
+      result = searchInScopes(c, ident, amb)
+      if result == nil:
+        let candidates = allPureEnumFields(c, ident)
+        if candidates.len > 0:
+          result = candidates[0]
+          amb = candidates.len > 1
+          if amb and checkAmbiguity in flags:
+            errorUseQualifier(c, n.info, candidates)
     else:
-      let candidates = searchInScopesFilterBy(c, ident, allExceptModule) #.skipAlias(n, c.config)
+      let candidates = lookUpCandidates(c, ident, allExceptModule)
       if candidates.len > 0:
         result = candidates[0]
         amb = candidates.len > 1
         if amb and checkAmbiguity in flags:
           errorUseQualifier(c, n.info, candidates)
-    if result == nil:
-      let candidates = allPureEnumFields(c, ident)
-      if candidates.len > 0:
-        result = candidates[0]
-        amb = candidates.len > 1
-        if amb and checkAmbiguity in flags:
-          errorUseQualifier(c, n.info, candidates)
-
+      else:
+        result = nil
     if result == nil and checkUndeclared in flags:
-      result = errorUndeclaredIdentifierHint(c, n, ident)
+      result = errorUndeclaredIdentifierHint(c, ident, n.info)
     elif checkAmbiguity in flags and result != nil and amb:
       result = errorUseQualifier(c, n.info, result, amb)
     c.isAmbiguous = amb
@@ -627,13 +676,20 @@ proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
         ident = considerQuotedIdent(c, n[1])
       if ident != nil:
         if m == c.module:
-          result = strTableGet(c.topLevelScope.symbols, ident).skipAlias(n, c.config)
+          result = strTableGet(c.topLevelScope.symbols, ident)
         else:
-          result = someSym(c.graph, m, ident).skipAlias(n, c.config)
+          if c.importModuleLookup.getOrDefault(m.name.id).len > 1:
+            var amb: bool = false
+            result = errorUseQualifier(c, n.info, m, amb)
+          else:
+            result = someSym(c.graph, m, ident)
         if result == nil and checkUndeclared in flags:
-          result = errorUndeclaredIdentifierHint(c, n[1], ident)
+          result = errorUndeclaredIdentifierHint(c, ident, n[1].info)
       elif n[1].kind == nkSym:
         result = n[1].sym
+        if result.owner != nil and result.owner != m and checkUndeclared in flags:
+          # dotExpr in templates can end up here
+          result = errorUndeclaredIdentifierHint(c, result.name, n[1].info)
       elif checkUndeclared in flags and
            n[1].kind notin {nkOpenSymChoice, nkClosedSymChoice}:
         localError(c.config, n[1].info, "identifier expected, but got: " &
@@ -649,11 +705,12 @@ proc initOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
   o.marked = initIntSet()
   case n.kind
   of nkIdent, nkAccQuoted:
+    result = nil
     var ident = considerQuotedIdent(c, n)
     var scope = c.currentScope
     o.mode = oimNoQualifier
     while true:
-      result = initIdentIter(o.it, scope.symbols, ident).skipAlias(n, c.config)
+      result = initIdentIter(o.it, scope.symbols, ident)
       if result != nil:
         o.currentScope = scope
         break
@@ -661,7 +718,7 @@ proc initOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
         scope = scope.parent
         if scope == nil:
           for i in 0..c.imports.high:
-            result = initIdentIter(o.mit, o.marked, c.imports[i], ident, c.graph).skipAlias(n, c.config)
+            result = initIdentIter(o.mit, o.marked, c.imports[i], ident, c.graph)
             if result != nil:
               o.currentScope = nil
               o.importIdx = i
@@ -672,6 +729,7 @@ proc initOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
     result = n.sym
     o.mode = oimDone
   of nkDotExpr:
+    result = nil
     o.mode = oimOtherModule
     o.m = qualifiedLookUp(c, n[0], {checkUndeclared, checkModule})
     if o.m != nil and o.m.kind == skModule:
@@ -684,10 +742,10 @@ proc initOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
         if o.m == c.module:
           # a module may access its private members:
           result = initIdentIter(o.it, c.topLevelScope.symbols,
-                                 ident).skipAlias(n, c.config)
+                                 ident)
           o.mode = oimSelfModule
         else:
-          result = initModuleIter(o.mit, c.graph, o.m, ident).skipAlias(n, c.config)
+          result = initModuleIter(o.mit, c.graph, o.m, ident)
       else:
         noidentError(c.config, n[1], n)
         result = errorSym(c, n[1])
@@ -701,7 +759,7 @@ proc initOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
     o.symChoiceIndex = 1
     o.marked = initIntSet()
     incl(o.marked, result.id)
-  else: discard
+  else: result = nil
   when false:
     if result != nil and result.kind == skStub: loadStub(result)
 
@@ -716,11 +774,12 @@ proc lastOverloadScope*(o: TOverloadIter): int =
   else: result = -1
 
 proc nextOverloadIterImports(o: var TOverloadIter, c: PContext, n: PNode): PSym =
+  result = nil
   assert o.currentScope == nil
   var idx = o.importIdx+1
   o.importIdx = c.imports.len # assume the other imported modules lack this symbol too
   while idx < c.imports.len:
-    result = initIdentIter(o.mit, o.marked, c.imports[idx], o.it.name, c.graph).skipAlias(n, c.config)
+    result = initIdentIter(o.mit, o.marked, c.imports[idx], o.it.name, c.graph)
     if result != nil:
       # oh, we were wrong, some other module had the symbol, so remember that:
       o.importIdx = idx
@@ -728,9 +787,10 @@ proc nextOverloadIterImports(o: var TOverloadIter, c: PContext, n: PNode): PSym
     inc idx
 
 proc symChoiceExtension(o: var TOverloadIter; c: PContext; n: PNode): PSym =
+  result = nil
   assert o.currentScope == nil
   while o.importIdx < c.imports.len:
-    result = initIdentIter(o.mit, o.marked, c.imports[o.importIdx], o.it.name, c.graph).skipAlias(n, c.config)
+    result = initIdentIter(o.mit, o.marked, c.imports[o.importIdx], o.it.name, c.graph)
     #while result != nil and result.id in o.marked:
     #  result = nextIdentIter(o.it, o.marked, c.imports[o.importIdx])
     if result != nil:
@@ -745,29 +805,29 @@ proc nextOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
   of oimNoQualifier:
     if o.currentScope != nil:
       assert o.importIdx < 0
-      result = nextIdentIter(o.it, o.currentScope.symbols).skipAlias(n, c.config)
+      result = nextIdentIter(o.it, o.currentScope.symbols)
       while result == nil:
         o.currentScope = o.currentScope.parent
         if o.currentScope != nil:
-          result = initIdentIter(o.it, o.currentScope.symbols, o.it.name).skipAlias(n, c.config)
+          result = initIdentIter(o.it, o.currentScope.symbols, o.it.name)
           # BUGFIX: o.it.name <-> n.ident
         else:
           o.importIdx = 0
           if c.imports.len > 0:
-            result = initIdentIter(o.mit, o.marked, c.imports[o.importIdx], o.it.name, c.graph).skipAlias(n, c.config)
+            result = initIdentIter(o.mit, o.marked, c.imports[o.importIdx], o.it.name, c.graph)
             if result == nil:
               result = nextOverloadIterImports(o, c, n)
           break
     elif o.importIdx < c.imports.len:
-      result = nextIdentIter(o.mit, o.marked, c.imports[o.importIdx], c.graph).skipAlias(n, c.config)
+      result = nextIdentIter(o.mit, o.marked, c.imports[o.importIdx], c.graph)
       if result == nil:
         result = nextOverloadIterImports(o, c, n)
     else:
       result = nil
   of oimSelfModule:
-    result = nextIdentIter(o.it, c.topLevelScope.symbols).skipAlias(n, c.config)
+    result = nextIdentIter(o.it, c.topLevelScope.symbols)
   of oimOtherModule:
-    result = nextModuleIter(o.mit, c.graph).skipAlias(n, c.config)
+    result = nextModuleIter(o.mit, c.graph)
   of oimSymChoice:
     if o.symChoiceIndex < n.len:
       result = n[o.symChoiceIndex].sym
@@ -778,26 +838,28 @@ proc nextOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
       o.mode = oimSymChoiceLocalLookup
       o.currentScope = c.currentScope
       result = firstIdentExcluding(o.it, o.currentScope.symbols,
-                                   n[0].sym.name, o.marked).skipAlias(n, c.config)
+                                   n[0].sym.name, o.marked)
       while result == nil:
         o.currentScope = o.currentScope.parent
         if o.currentScope != nil:
           result = firstIdentExcluding(o.it, o.currentScope.symbols,
-                                      n[0].sym.name, o.marked).skipAlias(n, c.config)
+                                      n[0].sym.name, o.marked)
         else:
           o.importIdx = 0
           result = symChoiceExtension(o, c, n)
           break
       if result != nil:
         incl o.marked, result.id
+    else:
+      result = nil
   of oimSymChoiceLocalLookup:
     if o.currentScope != nil:
-      result = nextIdentExcluding(o.it, o.currentScope.symbols, o.marked).skipAlias(n, c.config)
+      result = nextIdentExcluding(o.it, o.currentScope.symbols, o.marked)
       while result == nil:
         o.currentScope = o.currentScope.parent
         if o.currentScope != nil:
           result = firstIdentExcluding(o.it, o.currentScope.symbols,
-                                      n[0].sym.name, o.marked).skipAlias(n, c.config)
+                                      n[0].sym.name, o.marked)
         else:
           o.importIdx = 0
           result = symChoiceExtension(o, c, n)
@@ -806,20 +868,23 @@ proc nextOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
         incl o.marked, result.id
 
     elif o.importIdx < c.imports.len:
-      result = nextIdentIter(o.mit, o.marked, c.imports[o.importIdx], c.graph).skipAlias(n, c.config)
+      result = nextIdentIter(o.mit, o.marked, c.imports[o.importIdx], c.graph)
       #assert result.id notin o.marked
       #while result != nil and result.id in o.marked:
-      #  result = nextIdentIter(o.it, c.imports[o.importIdx]).skipAlias(n, c.config)
+      #  result = nextIdentIter(o.it, c.imports[o.importIdx])
       if result == nil:
         inc o.importIdx
         result = symChoiceExtension(o, c, n)
+    else:
+      result = nil
 
   when false:
     if result != nil and result.kind == skStub: loadStub(result)
 
 proc pickSym*(c: PContext, n: PNode; kinds: set[TSymKind];
               flags: TSymFlags = {}): PSym =
-  var o: TOverloadIter
+  result = nil
+  var o: TOverloadIter = default(TOverloadIter)
   var a = initOverloadIter(o, c, n)
   while a != nil:
     if a.kind in kinds and flags <= a.flags:

compiler/lowerings.nim

@@ -19,7 +19,7 @@ when defined(nimPreviewSlimSystem):
   import std/assertions
 
 proc newDeref*(n: PNode): PNode {.inline.} =
-  result = newNodeIT(nkHiddenDeref, n.info, n.typ[0])
+  result = newNodeIT(nkHiddenDeref, n.info, n.typ.elementType)
   result.add n
 
 proc newTupleAccess*(g: ModuleGraph; tup: PNode, i: int): PNode =
@@ -79,7 +79,7 @@ proc lowerTupleUnpacking*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: P
   if avoidTemp:
     tempAsNode = value
   else:
-    var temp = newSym(skTemp, getIdent(g.cache, genPrefix), nextSymId(idgen),
+    var temp = newSym(skTemp, getIdent(g.cache, genPrefix), idgen,
                   owner, value.info, g.config.options)
     temp.typ = skipTypes(value.typ, abstractInst)
     incl(temp.flags, sfFromGeneric)
@@ -100,7 +100,7 @@ proc evalOnce*(g: ModuleGraph; value: PNode; idgen: IdGenerator; owner: PSym): P
   ## freely, multiple times. This is frequently required and such a builtin would also be
   ## handy to have in macros.nim. The value that can be reused is 'result.lastSon'!
   result = newNodeIT(nkStmtListExpr, value.info, value.typ)
-  var temp = newSym(skTemp, getIdent(g.cache, genPrefix), nextSymId(idgen),
+  var temp = newSym(skTemp, getIdent(g.cache, genPrefix), idgen,
                     owner, value.info, g.config.options)
   temp.typ = skipTypes(value.typ, abstractInst)
   incl(temp.flags, sfFromGeneric)
@@ -122,29 +122,10 @@ proc newTupleAccessRaw*(tup: PNode, i: int): PNode =
 proc newTryFinally*(body, final: PNode): PNode =
   result = newTree(nkHiddenTryStmt, body, newTree(nkFinally, final))
 
-proc lowerTupleUnpackingForAsgn*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PNode =
-  let value = n.lastSon
-  result = newNodeI(nkStmtList, n.info)
-
-  var temp = newSym(skTemp, getIdent(g.cache, "_"), nextSymId(idgen), owner, value.info, owner.options)
-  var v = newNodeI(nkLetSection, value.info)
-  let tempAsNode = newSymNode(temp) #newIdentNode(getIdent(genPrefix & $temp.id), value.info)
-
-  var vpart = newNodeI(nkIdentDefs, tempAsNode.info, 3)
-  vpart[0] = tempAsNode
-  vpart[1] = newNodeI(nkEmpty, value.info)
-  vpart[2] = value
-  v.add vpart
-  result.add(v)
-
-  let lhs = n[0]
-  for i in 0..<lhs.len:
-    result.add newAsgnStmt(lhs[i], newTupleAccessRaw(tempAsNode, i))
-
 proc lowerSwap*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PNode =
   result = newNodeI(nkStmtList, n.info)
   # note: cannot use 'skTemp' here cause we really need the copy for the VM :-(
-  var temp = newSym(skVar, getIdent(g.cache, genPrefix), nextSymId(idgen), owner, n.info, owner.options)
+  var temp = newSym(skVar, getIdent(g.cache, genPrefix), idgen, owner, n.info, owner.options)
   temp.typ = n[1].typ
   incl(temp.flags, sfFromGeneric)
   incl(temp.flags, sfGenSym)
@@ -163,7 +144,7 @@ proc lowerSwap*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PNod
   result.add newFastAsgnStmt(n[2], tempAsNode)
 
 proc createObj*(g: ModuleGraph; idgen: IdGenerator; owner: PSym, info: TLineInfo; final=true): PType =
-  result = newType(tyObject, nextTypeId(idgen), owner)
+  result = newType(tyObject, idgen, owner)
   if final:
     rawAddSon(result, nil)
     incl result.flags, tfFinal
@@ -171,8 +152,7 @@ proc createObj*(g: ModuleGraph; idgen: IdGenerator; owner: PSym, info: TLineInfo
     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),
-                  nextSymId(idgen),
-                  owner, info, owner.options)
+                  idgen, owner, info, owner.options)
   incl s.flags, sfAnon
   s.typ = result
   result.sym = s
@@ -234,10 +214,13 @@ proc addField*(obj: PType; s: PSym; cache: IdentCache; idgen: IdGenerator): PSym
   # 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),
-                     nextSymId(idgen), s.owner, s.info, s.options)
+                     idgen, s.owner, s.info, s.options)
   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}:
+    #field.bitsize = s.bitsize
+    field.alignment = s.alignment
   assert t.kind != tyTyped
   propagateToOwner(obj, t)
   field.position = obj.n.len
@@ -250,7 +233,7 @@ proc addField*(obj: PType; s: PSym; cache: IdentCache; idgen: IdGenerator): PSym
 proc addUniqueField*(obj: PType; s: PSym; cache: IdentCache; idgen: IdGenerator): PSym {.discardable.} =
   result = lookupInRecord(obj.n, s.itemId)
   if result == nil:
-    var field = newSym(skField, getIdent(cache, s.name.s & $obj.n.len), nextSymId(idgen),
+    var field = newSym(skField, getIdent(cache, s.name.s & $obj.n.len), idgen,
                        s.owner, s.info, s.options)
     field.itemId = ItemId(module: s.itemId.module, item: -s.itemId.item)
     let t = skipIntLit(s.typ, idgen)
@@ -272,14 +255,14 @@ proc newDotExpr*(obj, b: PSym): PNode =
 proc indirectAccess*(a: PNode, b: ItemId, info: TLineInfo): PNode =
   # returns a[].b as a node
   var deref = newNodeI(nkHiddenDeref, info)
-  deref.typ = a.typ.skipTypes(abstractInst)[0]
+  deref.typ = a.typ.skipTypes(abstractInst).elementType
   var t = deref.typ.skipTypes(abstractInst)
   var field: PSym
   while true:
     assert t.kind == tyObject
     field = lookupInRecord(t.n, b)
     if field != nil: break
-    t = t[0]
+    t = t.baseClass
     if t == nil: break
     t = t.skipTypes(skipPtrs)
   #if field == nil:
@@ -295,7 +278,7 @@ proc indirectAccess*(a: PNode, b: ItemId, info: TLineInfo): PNode =
 proc indirectAccess*(a: PNode, b: string, info: TLineInfo; cache: IdentCache): PNode =
   # returns a[].b as a node
   var deref = newNodeI(nkHiddenDeref, info)
-  deref.typ = a.typ.skipTypes(abstractInst)[0]
+  deref.typ = a.typ.skipTypes(abstractInst).elementType
   var t = deref.typ.skipTypes(abstractInst)
   var field: PSym
   let bb = getIdent(cache, b)
@@ -303,7 +286,7 @@ proc indirectAccess*(a: PNode, b: string, info: TLineInfo; cache: IdentCache): P
     assert t.kind == tyObject
     field = getSymFromList(t.n, bb)
     if field != nil: break
-    t = t[0]
+    t = t.baseClass
     if t == nil: break
     t = t.skipTypes(skipPtrs)
   #if field == nil:
@@ -323,7 +306,7 @@ proc getFieldFromObj*(t: PType; v: PSym): PSym =
     assert t.kind == tyObject
     result = lookupInRecord(t.n, v.itemId)
     if result != nil: break
-    t = t[0]
+    t = t.baseClass
     if t == nil: break
     t = t.skipTypes(skipPtrs)
 
@@ -337,17 +320,18 @@ proc indirectAccess*(a, b: PSym, info: TLineInfo): PNode =
 proc genAddrOf*(n: PNode; idgen: IdGenerator; typeKind = tyPtr): PNode =
   result = newNodeI(nkAddr, n.info, 1)
   result[0] = n
-  result.typ = newType(typeKind, nextTypeId(idgen), n.typ.owner)
+  result.typ = newType(typeKind, idgen, n.typ.owner)
   result.typ.rawAddSon(n.typ)
 
 proc genDeref*(n: PNode; k = nkHiddenDeref): PNode =
   result = newNodeIT(k, n.info,
-                     n.typ.skipTypes(abstractInst)[0])
+                     n.typ.skipTypes(abstractInst).elementType)
   result.add n
 
 proc callCodegenProc*(g: ModuleGraph; name: string;
                       info: TLineInfo = unknownLineInfo;
-                      arg1, arg2, arg3, optionalArgs: PNode = nil): PNode =
+                      arg1: PNode = nil, arg2: PNode = nil,
+                      arg3: PNode = nil, optionalArgs: PNode = nil): PNode =
   result = newNodeI(nkCall, info)
   let sym = magicsys.getCompilerProc(g, name)
   if sym == nil:
@@ -360,7 +344,7 @@ proc callCodegenProc*(g: ModuleGraph; name: string;
     if optionalArgs != nil:
       for i in 1..<optionalArgs.len-2:
         result.add optionalArgs[i]
-    result.typ = sym.typ[0]
+    result.typ = sym.typ.returnType
 
 proc newIntLit*(g: ModuleGraph; info: TLineInfo; value: BiggestInt): PNode =
   result = nkIntLit.newIntNode(value)

compiler/magicsys.nim

@@ -18,7 +18,7 @@ export createMagic
 proc nilOrSysInt*(g: ModuleGraph): PType = g.sysTypes[tyInt]
 
 proc newSysType(g: ModuleGraph; kind: TTypeKind, size: int): PType =
-  result = newType(kind, nextTypeId(g.idgen), g.systemModule)
+  result = newType(kind, g.idgen, g.systemModule)
   result.size = size
   result.align = size.int16
 
@@ -26,21 +26,21 @@ proc getSysSym*(g: ModuleGraph; info: TLineInfo; name: string): PSym =
   result = systemModuleSym(g, getIdent(g.cache, name))
   if result == nil:
     localError(g.config, info, "system module needs: " & name)
-    result = newSym(skError, getIdent(g.cache, name), nextSymId(g.idgen), g.systemModule, g.systemModule.info, {})
-    result.typ = newType(tyError, nextTypeId(g.idgen), g.systemModule)
-  if result.kind == skAlias: result = result.owner
+    result = newSym(skError, getIdent(g.cache, name), g.idgen, g.systemModule, g.systemModule.info, {})
+    result.typ = newType(tyError, g.idgen, g.systemModule)
 
 proc getSysMagic*(g: ModuleGraph; info: TLineInfo; name: string, m: TMagic): PSym =
+  result = nil
   let id = getIdent(g.cache, name)
   for r in systemModuleSyms(g, id):
     if r.magic == m:
       # prefer the tyInt variant:
-      if r.typ[0] != nil and r.typ[0].kind == tyInt: return r
+      if r.typ.returnType != nil and r.typ.returnType.kind == tyInt: return r
       result = r
   if result != nil: return result
   localError(g.config, info, "system module needs: " & name)
-  result = newSym(skError, id, nextSymId(g.idgen), g.systemModule, g.systemModule.info, {})
-  result.typ = newType(tyError, nextTypeId(g.idgen), g.systemModule)
+  result = newSym(skError, id, g.idgen, g.systemModule, g.systemModule.info, {})
+  result.typ = newType(tyError, g.idgen, g.systemModule)
 
 proc sysTypeFromName*(g: ModuleGraph; info: TLineInfo; name: string): PType =
   result = getSysSym(g, info, name).typ
@@ -81,8 +81,8 @@ proc getSysType*(g: ModuleGraph; info: TLineInfo; kind: TTypeKind): PType =
 
 proc resetSysTypes*(g: ModuleGraph) =
   g.systemModule = nil
-  initStrTable(g.compilerprocs)
-  initStrTable(g.exposed)
+  g.compilerprocs = initStrTable()
+  g.exposed = initStrTable()
   for i in low(g.sysTypes)..high(g.sysTypes):
     g.sysTypes[i] = nil
 
@@ -93,16 +93,23 @@ proc getFloatLitType*(g: ModuleGraph; literal: PNode): PType =
 
 proc skipIntLit*(t: PType; id: IdGenerator): PType {.inline.} =
   if t.n != nil and t.kind in {tyInt, tyFloat}:
-    result = copyType(t, nextTypeId(id), t.owner)
+    result = copyType(t, id, t.owner)
     result.n = nil
   else:
     result = t
 
 proc addSonSkipIntLit*(father, son: PType; id: IdGenerator) =
   let s = son.skipIntLit(id)
-  father.sons.add(s)
+  father.add(s)
   propagateToOwner(father, s)
 
+proc makeVarType*(owner: PSym; baseType: PType; idgen: IdGenerator; kind = tyVar): PType =
+  if baseType.kind == kind:
+    result = baseType
+  else:
+    result = newType(kind, idgen, owner)
+    addSonSkipIntLit(result, baseType, idgen)
+
 proc getCompilerProc*(g: ModuleGraph; name: string): PSym =
   let ident = getIdent(g.cache, name)
   result = strTableGet(g.compilerprocs, ident)
@@ -124,7 +131,7 @@ proc registerNimScriptSymbol*(g: ModuleGraph; s: PSym) =
 proc getNimScriptSymbol*(g: ModuleGraph; name: string): PSym =
   strTableGet(g.exposed, getIdent(g.cache, name))
 
-proc resetNimScriptSymbols*(g: ModuleGraph) = initStrTable(g.exposed)
+proc resetNimScriptSymbols*(g: ModuleGraph) = g.exposed = initStrTable()
 
 proc getMagicEqSymForType*(g: ModuleGraph; t: PType; info: TLineInfo): PSym =
   case t.kind
@@ -146,7 +153,17 @@ proc getMagicEqSymForType*(g: ModuleGraph; t: PType; info: TLineInfo): PSym =
   of tyProc:
     result = getSysMagic(g, info, "==", mEqProc)
   else:
+    result = nil
     globalError(g.config, info,
       "can't find magic equals operator for type kind " & $t.kind)
 
+proc makePtrType*(baseType: PType; idgen: IdGenerator): PType =
+  result = newType(tyPtr, idgen, baseType.owner)
+  addSonSkipIntLit(result, baseType, idgen)
 
+proc makeAddr*(n: PNode; idgen: IdGenerator): PNode =
+  if n.kind == nkHiddenAddr:
+    result = n
+  else:
+    result = newTree(nkHiddenAddr, n)
+    result.typ = makePtrType(n.typ, idgen)

compiler/main.nim

@@ -13,7 +13,7 @@ when not defined(nimcore):
   {.error: "nimcore MUST be defined for Nim's core tooling".}
 
 import
-  std/[strutils, os, times, tables, sha1, with, json],
+  std/[strutils, os, times, tables, with, json],
   llstream, ast, lexer, syntaxes, options, msgs,
   condsyms,
   idents, extccomp,
@@ -22,12 +22,15 @@ import
   modules,
   modulegraphs, lineinfos, pathutils, vmprofiler
 
+# ensure NIR compiles:
+import nir / nir
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions]
 
-import ic / [cbackend, integrity, navigator]
-from ic / ic import rodViewer
+import ic / [cbackend, integrity, navigator, ic]
+
+import ../dist/checksums/src/checksums/sha1
 
 import pipelines
 
@@ -45,6 +48,9 @@ proc writeDepsFile(g: ModuleGraph) =
       f.writeLine(toFullPath(g.config, k))
   f.close()
 
+proc writeNinjaFile(g: ModuleGraph) =
+  discard "to implement"
+
 proc writeCMakeDepsFile(conf: ConfigRef) =
   ## write a list of C files for build systems like CMake.
   ## only updated when the C file list changes.
@@ -54,7 +60,7 @@ proc writeCMakeDepsFile(conf: ConfigRef) =
   for it in conf.toCompile: cfiles.add(it.cname.string)
   let fileset = cfiles.toCountTable()
   # read old cfiles list
-  var fl: File
+  var fl: File = default(File)
   var prevset = initCountTable[string]()
   if open(fl, fname.string, fmRead):
     for line in fl.lines: prevset.inc(line)
@@ -113,7 +119,7 @@ when not defined(leanCompiler):
       setPipeLinePass(graph, Docgen2JsonPass)
     of HtmlExt:
       setPipeLinePass(graph, Docgen2Pass)
-    else: doAssert false, $ext
+    else: raiseAssert $ext
     compilePipelineProject(graph)
 
 proc commandCompileToC(graph: ModuleGraph) =
@@ -149,12 +155,32 @@ proc commandCompileToC(graph: ModuleGraph) =
     extccomp.callCCompiler(conf)
     # for now we do not support writing out a .json file with the build instructions when HCR is on
     if not conf.hcrOn:
-      extccomp.writeJsonBuildInstructions(conf)
+      extccomp.writeJsonBuildInstructions(conf, graph.cachedFiles)
     if optGenScript in graph.config.globalOptions:
       writeDepsFile(graph)
     if optGenCDeps in graph.config.globalOptions:
       writeCMakeDepsFile(conf)
 
+proc commandCompileToNir(graph: ModuleGraph) =
+  let conf = graph.config
+  extccomp.initVars(conf)
+  if conf.symbolFiles == disabledSf:
+    if {optRun, optForceFullMake} * conf.globalOptions == {optRun}:
+      if not changeDetectedViaJsonBuildInstructions(conf, conf.jsonBuildInstructionsFile):
+        # nothing changed
+        graph.config.notes = graph.config.mainPackageNotes
+        return
+
+  if not extccomp.ccHasSaneOverflow(conf):
+    conf.symbols.defineSymbol("nimEmulateOverflowChecks")
+
+  if conf.symbolFiles == disabledSf:
+    setPipeLinePass(graph, NirPass)
+  else:
+    setPipeLinePass(graph, SemPass)
+  compilePipelineProject(graph)
+  writeNinjaFile(graph)
+
 proc commandJsonScript(graph: ModuleGraph) =
   extccomp.runJsonBuildInstructions(graph.config, graph.config.jsonBuildInstructionsFile)
 
@@ -171,13 +197,16 @@ proc commandCompileToJS(graph: ModuleGraph) =
     if optGenScript in conf.globalOptions:
       writeDepsFile(graph)
 
-proc commandInteractive(graph: ModuleGraph) =
+proc commandInteractive(graph: ModuleGraph; useNir: bool) =
   graph.config.setErrorMaxHighMaybe
   initDefines(graph.config.symbols)
-  defineSymbol(graph.config.symbols, "nimscript")
+  if useNir:
+    defineSymbol(graph.config.symbols, "noSignalHandler")
+  else:
+    defineSymbol(graph.config.symbols, "nimscript")
   # note: seems redundant with -d:nimHasLibFFI
   when hasFFI: defineSymbol(graph.config.symbols, "nimffi")
-  setPipeLinePass(graph, InterpreterPass)
+  setPipeLinePass(graph, if useNir: NirReplPass else: InterpreterPass)
   compilePipelineSystemModule(graph)
   if graph.config.commandArgs.len > 0:
     discard graph.compilePipelineModule(fileInfoIdx(graph.config, graph.config.projectFull), {})
@@ -193,9 +222,8 @@ proc commandScan(cache: IdentCache, config: ConfigRef) =
   var stream = llStreamOpen(f, fmRead)
   if stream != nil:
     var
-      L: Lexer
-      tok: Token
-    initToken(tok)
+      L: Lexer = default(Lexer)
+      tok: Token = default(Token)
     openLexer(L, f, stream, cache, config)
     while true:
       rawGetTok(L, tok)
@@ -265,7 +293,9 @@ proc mainCommand*(graph: ModuleGraph) =
         # and it has added this define implictly, so we must undo that here.
         # A better solution might be to fix system.nim
         undefSymbol(conf.symbols, "useNimRtl")
-    of backendInvalid: doAssert false
+    of backendNir:
+      if conf.exc == excNone: conf.exc = excGoto
+    of backendInvalid: raiseAssert "unreachable"
 
   proc compileToBackend() =
     customizeForBackend(conf.backend)
@@ -275,7 +305,8 @@ proc mainCommand*(graph: ModuleGraph) =
     of backendCpp: commandCompileToC(graph)
     of backendObjc: commandCompileToC(graph)
     of backendJs: commandCompileToJS(graph)
-    of backendInvalid: doAssert false
+    of backendNir: commandCompileToNir(graph)
+    of backendInvalid: raiseAssert "unreachable"
 
   template docLikeCmd(body) =
     when defined(leanCompiler):
@@ -295,14 +326,18 @@ proc mainCommand*(graph: ModuleGraph) =
     # so by default should not end up in $PWD nor in $projectPath.
     var ret = if optUseNimcache in conf.globalOptions: getNimcacheDir(conf)
               else: conf.projectPath
-    doAssert ret.string.isAbsolute # `AbsoluteDir` is not a real guarantee
+    if not ret.string.isAbsolute: # `AbsoluteDir` is not a real guarantee
+      rawMessage(conf, errCannotOpenFile, ret.string & "/")
     if conf.cmd in cmdDocLike + {cmdRst2html, cmdRst2tex, cmdMd2html, cmdMd2tex}:
       ret = ret / htmldocsDir
     conf.outDir = ret
 
   ## process all commands
   case conf.cmd
-  of cmdBackends: compileToBackend()
+  of cmdBackends:
+    compileToBackend()
+    when BenchIC:
+      echoTimes graph.packed
   of cmdTcc:
     when hasTinyCBackend:
       extccomp.setCC(conf, "tcc", unknownLineInfo)
@@ -398,6 +433,10 @@ proc mainCommand*(graph: ModuleGraph) =
       for it in conf.searchPaths: msgWriteln(conf, it.string)
   of cmdCheck:
     commandCheck(graph)
+  of cmdM:
+    graph.config.symbolFiles = v2Sf
+    setUseIc(graph.config.symbolFiles != disabledSf)
+    commandCheck(graph)
   of cmdParse:
     wantMainModule(conf)
     discard parseFile(conf.projectMainIdx, cache, conf)
@@ -405,7 +444,7 @@ proc mainCommand*(graph: ModuleGraph) =
     wantMainModule(conf)
     commandView(graph)
     #msgWriteln(conf, "Beware: Indentation tokens depend on the parser's state!")
-  of cmdInteractive: commandInteractive(graph)
+  of cmdInteractive: commandInteractive(graph, isDefined(conf, "nir"))
   of cmdNimscript:
     if conf.projectIsCmd or conf.projectIsStdin: discard
     elif not fileExists(conf.projectFull):
@@ -415,7 +454,7 @@ proc mainCommand*(graph: ModuleGraph) =
   of cmdJsonscript:
     setOutFile(graph.config)
     commandJsonScript(graph)
-  of cmdUnknown, cmdNone, cmdIdeTools, cmdNimfix:
+  of cmdUnknown, cmdNone, cmdIdeTools:
     rawMessage(conf, errGenerated, "invalid command: " & conf.command)
 
   if conf.errorCounter == 0 and conf.cmd notin {cmdTcc, cmdDump, cmdNop}:

compiler/mangleutils.nim

@@ -0,0 +1,59 @@
+import std/strutils
+import ast, modulegraphs
+
+proc mangle*(name: string): string =
+  result = newStringOfCap(name.len)
+  var start = 0
+  if name[0] in Digits:
+    result.add("X" & name[0])
+    start = 1
+  var requiresUnderscore = false
+  template special(x) =
+    result.add x
+    requiresUnderscore = true
+  for i in start..<name.len:
+    let c = name[i]
+    case c
+    of 'a'..'z', '0'..'9', 'A'..'Z':
+      result.add(c)
+    of '_':
+      # we generate names like 'foo_9' for scope disambiguations and so
+      # disallow this here:
+      if i > 0 and i < name.len-1 and name[i+1] in Digits:
+        discard
+      else:
+        result.add(c)
+    of '$': special "dollar"
+    of '%': special "percent"
+    of '&': special "amp"
+    of '^': special "roof"
+    of '!': special "emark"
+    of '?': special "qmark"
+    of '*': special "star"
+    of '+': special "plus"
+    of '-': special "minus"
+    of '/': special "slash"
+    of '\\': special "backslash"
+    of '=': special "eq"
+    of '<': special "lt"
+    of '>': special "gt"
+    of '~': special "tilde"
+    of ':': special "colon"
+    of '.': special "dot"
+    of '@': special "at"
+    of '|': special "bar"
+    else:
+      result.add("X" & toHex(ord(c), 2))
+      requiresUnderscore = true
+  if requiresUnderscore:
+    result.add "_"
+
+proc mangleParamExt*(s: PSym): string =
+  result = "_p"
+  result.addInt s.position
+
+proc mangleProcNameExt*(graph: ModuleGraph, s: PSym): string =
+  result = "__"
+  result.add graph.ifaces[s.itemId.module].uniqueName
+  result.add "_u"
+  result.addInt s.itemId.item # s.disamb #

compiler/modulegraphs.nim

@@ -11,10 +11,12 @@
 ## represents a complete Nim project. Single modules can either be kept in RAM
 ## or stored in a rod-file.
 
-import intsets, tables, hashes, md5
-import ast, astalgo, options, lineinfos,idents, btrees, ropes, msgs, pathutils, packages
+import std/[intsets, tables, hashes, strtabs, algorithm]
+import ../dist/checksums/src/checksums/md5
+import ast, astalgo, options, lineinfos,idents, btrees, ropes, msgs, pathutils, packages, suggestsymdb
 import ic / [packed_ast, ic]
 
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -53,10 +55,6 @@ type
     concreteTypes*: seq[FullId]
     inst*: PInstantiation
 
-  SymInfoPair* = object
-    sym*: PSym
-    info*: TLineInfo
-
   PipelinePass* = enum
     NonePass
     SemPass
@@ -64,6 +62,8 @@ type
     CgenPass
     EvalPass
     InterpreterPass
+    NirPass
+    NirReplPass
     GenDependPass
     Docgen2TexPass
     Docgen2JsonPass
@@ -77,7 +77,9 @@ type
     typeInstCache*: Table[ItemId, seq[LazyType]] # A symbol's ItemId.
     procInstCache*: Table[ItemId, seq[LazyInstantiation]] # A symbol's ItemId.
     attachedOps*: array[TTypeAttachedOp, Table[ItemId, LazySym]] # Type ID, destructors, etc.
-    methodsPerType*: Table[ItemId, seq[(int, LazySym)]] # Type ID, attached methods
+    methodsPerGenericType*: Table[ItemId, seq[(int, LazySym)]] # Type ID, attached methods
+    memberProcsPerType*: Table[ItemId, seq[PSym]] # Type ID, attached member procs (only c++, virtual,member and ctor so far).
+    initializersPerType*: Table[ItemId, PNode] # Type ID, AST call to the default ctor (c++ only)
     enumToStringProcs*: Table[ItemId, LazySym]
     emittedTypeInfo*: Table[string, FileIndex]
 
@@ -87,6 +89,7 @@ type
     importDeps*: Table[FileIndex, seq[FileIndex]] # explicit import module dependencies
     suggestMode*: bool # whether we are in nimsuggest mode or not.
     invalidTransitiveClosure: bool
+    interactive*: bool
     inclToMod*: Table[FileIndex, FileIndex] # mapping of include file to the
                                             # first module that included it
     importStack*: seq[FileIndex]  # The current import stack. Used for detecting recursive
@@ -96,12 +99,18 @@ type
     cache*: IdentCache
     vm*: RootRef # unfortunately the 'vm' state is shared project-wise, this will
                  # be clarified in later compiler implementations.
+    repl*: RootRef # REPL state is shared project-wise.
     doStopCompile*: proc(): bool {.closure.}
     usageSym*: PSym # for nimsuggest
     owners*: seq[PSym]
-    suggestSymbols*: Table[FileIndex, seq[SymInfoPair]]
+    suggestSymbols*: SuggestSymbolDatabase
     suggestErrors*: Table[FileIndex, seq[Suggest]]
     methods*: seq[tuple[methods: seq[PSym], dispatcher: PSym]] # needs serialization!
+    bucketTable*: CountTable[ItemId]
+    objectTree*: Table[ItemId, seq[tuple[depth: int, value: PType]]]
+    methodsPerType*: Table[ItemId, seq[LazySym]]
+    dispatchers*: seq[LazySym]
+
     systemModule*: PSym
     sysTypes*: array[TTypeKind, PType]
     compilerprocs*: TStrTable
@@ -126,6 +135,8 @@ type
     idgen*: IdGenerator
     operators*: Operators
 
+    cachedFiles*: StringTableRef
+
   TPassContext* = object of RootObj # the pass's context
     idgen*: IdGenerator
   PPassContext* = ref TPassContext
@@ -140,13 +151,15 @@ type
                  isFrontend: bool]
 
 proc resetForBackend*(g: ModuleGraph) =
-  initStrTable(g.compilerprocs)
+  g.compilerprocs = initStrTable()
   g.typeInstCache.clear()
   g.procInstCache.clear()
   for a in mitems(g.attachedOps):
     a.clear()
-  g.methodsPerType.clear()
+  g.methodsPerGenericType.clear()
   g.enumToStringProcs.clear()
+  g.dispatchers.setLen(0)
+  g.methodsPerType.clear()
 
 const
   cb64 = [
@@ -194,8 +207,8 @@ template semtabAll*(g: ModuleGraph, m: PSym): TStrTable =
   g.ifaces[m.position].interfHidden
 
 proc initStrTables*(g: ModuleGraph, m: PSym) =
-  initStrTable(semtab(g, m))
-  initStrTable(semtabAll(g, m))
+  semtab(g, m) = initStrTable()
+  semtabAll(g, m) = initStrTable()
 
 proc strTableAdds*(g: ModuleGraph, m: PSym, s: PSym) =
   strTableAdd(semtab(g, m), s)
@@ -204,10 +217,10 @@ proc strTableAdds*(g: ModuleGraph, m: PSym, s: PSym) =
 proc isCachedModule(g: ModuleGraph; module: int): bool {.inline.} =
   result = module < g.packed.len and g.packed[module].status == loaded
 
-proc isCachedModule(g: ModuleGraph; m: PSym): bool {.inline.} =
+proc isCachedModule*(g: ModuleGraph; m: PSym): bool {.inline.} =
   isCachedModule(g, m.position)
 
-proc simulateCachedModule*(g: ModuleGraph; moduleSym: PSym; m: PackedModule) =
+proc simulateCachedModule(g: ModuleGraph; moduleSym: PSym; m: PackedModule) =
   when false:
     echo "simulating ", moduleSym.name.s, " ", moduleSym.position
   simulateLoadedModule(g.packed, g.config, g.cache, moduleSym, m)
@@ -246,7 +259,7 @@ proc nextModuleIter*(mi: var ModuleIter; g: ModuleGraph): PSym =
 iterator allSyms*(g: ModuleGraph; m: PSym): PSym =
   let importHidden = optImportHidden in m.options
   if isCachedModule(g, m):
-    var rodIt: RodIter
+    var rodIt: RodIter = default(RodIter)
     var r = initRodIterAllSyms(rodIt, g.config, g.cache, g.packed, FileIndex m.position, importHidden)
     while r != nil:
       yield r
@@ -267,7 +280,7 @@ proc systemModuleSym*(g: ModuleGraph; name: PIdent): PSym =
   result = someSym(g, g.systemModule, name)
 
 iterator systemModuleSyms*(g: ModuleGraph; name: PIdent): PSym =
-  var mi: ModuleIter
+  var mi: ModuleIter = default(ModuleIter)
   var r = initModuleIter(mi, g, g.systemModule, name)
   while r != nil:
     yield r
@@ -317,6 +330,7 @@ iterator procInstCacheItems*(g: ModuleGraph; s: PSym): PInstantiation =
     for t in mitems(x[]):
       yield resolveInst(g, t)
 
+
 proc getAttachedOp*(g: ModuleGraph; t: PType; op: TTypeAttachedOp): PSym =
   ## returns the requested attached operation for type `t`. Can return nil
   ## if no such operation exists.
@@ -340,6 +354,27 @@ proc completePartialOp*(g: ModuleGraph; module: int; t: PType; op: TTypeAttached
     toPackedGeneratedProcDef(value, g.encoders[module], g.packed[module].fromDisk)
     #storeAttachedProcDef(t, op, value, g.encoders[module], g.packed[module].fromDisk)
 
+iterator getDispatchers*(g: ModuleGraph): PSym =
+  for i in g.dispatchers.mitems:
+    yield resolveSym(g, i)
+
+proc addDispatchers*(g: ModuleGraph, value: PSym) =
+  # TODO: add it for packed modules
+  g.dispatchers.add LazySym(sym: value)
+
+iterator resolveLazySymSeq(g: ModuleGraph, list: var seq[LazySym]): PSym =
+  for it in list.mitems:
+    yield resolveSym(g, it)
+
+proc setMethodsPerType*(g: ModuleGraph; id: ItemId, methods: seq[LazySym]) =
+  # TODO: add it for packed modules
+  g.methodsPerType[id] = methods
+
+iterator getMethodsPerType*(g: ModuleGraph; t: PType): PSym =
+  if g.methodsPerType.contains(t.itemId):
+    for it in mitems g.methodsPerType[t.itemId]:
+      yield resolveSym(g, it)
+
 proc getToStringProc*(g: ModuleGraph; t: PType): PSym =
   result = resolveSym(g, g.enumToStringProcs[t.itemId])
   assert result != nil
@@ -348,12 +383,12 @@ proc setToStringProc*(g: ModuleGraph; t: PType; value: PSym) =
   g.enumToStringProcs[t.itemId] = LazySym(sym: value)
 
 iterator methodsForGeneric*(g: ModuleGraph; t: PType): (int, PSym) =
-  if g.methodsPerType.contains(t.itemId):
-    for it in mitems g.methodsPerType[t.itemId]:
+  if g.methodsPerGenericType.contains(t.itemId):
+    for it in mitems g.methodsPerGenericType[t.itemId]:
       yield (it[0], resolveSym(g, it[1]))
 
 proc addMethodToGeneric*(g: ModuleGraph; module: int; t: PType; col: int; m: PSym) =
-  g.methodsPerType.mgetOrPut(t.itemId, @[]).add (col, LazySym(sym: m))
+  g.methodsPerGenericType.mgetOrPut(t.itemId, @[]).add (col, LazySym(sym: m))
 
 proc hasDisabledAsgn*(g: ModuleGraph; t: PType): bool =
   let op = getAttachedOp(g, t, attachedAsgn)
@@ -366,10 +401,11 @@ proc copyTypeProps*(g: ModuleGraph; module: int; dest, src: PType) =
       setAttachedOp(g, module, dest, k, op)
 
 proc loadCompilerProc*(g: ModuleGraph; name: string): PSym =
+  result = nil
   if g.config.symbolFiles == disabledSf: return nil
 
   # slow, linear search, but the results are cached:
-  for module in 0..high(g.packed):
+  for module in 0..<len(g.packed):
     #if isCachedModule(g, module):
     let x = searchForCompilerproc(g.packed[module], name)
     if x >= 0:
@@ -411,7 +447,7 @@ proc stopCompile*(g: ModuleGraph): bool {.inline.} =
   result = g.doStopCompile != nil and g.doStopCompile()
 
 proc createMagic*(g: ModuleGraph; idgen: IdGenerator; name: string, m: TMagic): PSym =
-  result = newSym(skProc, getIdent(g.cache, name), nextSymId(idgen), nil, unknownLineInfo, {})
+  result = newSym(skProc, getIdent(g.cache, name), idgen, nil, unknownLineInfo, {})
   result.magic = m
   result.flags = {sfNeverRaises}
 
@@ -426,7 +462,7 @@ proc registerModule*(g: ModuleGraph; m: PSym) =
     setLen(g.ifaces, m.position + 1)
 
   if m.position >= g.packed.len:
-    setLen(g.packed, m.position + 1)
+    setLen(g.packed.pm, m.position + 1)
 
   g.ifaces[m.position] = Iface(module: m, converters: @[], patterns: @[],
                                uniqueName: rope(uniqueModuleName(g.config, FileIndex(m.position))))
@@ -438,37 +474,39 @@ proc registerModuleById*(g: ModuleGraph; m: FileIndex) =
 proc initOperators*(g: ModuleGraph): Operators =
   # These are safe for IC.
   # Public because it's used by DrNim.
-  result.opLe = createMagic(g, "<=", mLeI)
-  result.opLt = createMagic(g, "<", mLtI)
-  result.opAnd = createMagic(g, "and", mAnd)
-  result.opOr = createMagic(g, "or", mOr)
-  result.opIsNil = createMagic(g, "isnil", mIsNil)
-  result.opEq = createMagic(g, "==", mEqI)
-  result.opAdd = createMagic(g, "+", mAddI)
-  result.opSub = createMagic(g, "-", mSubI)
-  result.opMul = createMagic(g, "*", mMulI)
-  result.opDiv = createMagic(g, "div", mDivI)
-  result.opLen = createMagic(g, "len", mLengthSeq)
-  result.opNot = createMagic(g, "not", mNot)
-  result.opContains = createMagic(g, "contains", mInSet)
+  result = Operators(
+    opLe: createMagic(g, "<=", mLeI),
+    opLt: createMagic(g, "<", mLtI),
+    opAnd: createMagic(g, "and", mAnd),
+    opOr: createMagic(g, "or", mOr),
+    opIsNil: createMagic(g, "isnil", mIsNil),
+    opEq: createMagic(g, "==", mEqI),
+    opAdd: createMagic(g, "+", mAddI),
+    opSub: createMagic(g, "-", mSubI),
+    opMul: createMagic(g, "*", mMulI),
+    opDiv: createMagic(g, "div", mDivI),
+    opLen: createMagic(g, "len", mLengthSeq),
+    opNot: createMagic(g, "not", mNot),
+    opContains: createMagic(g, "contains", mInSet)
+  )
 
 proc initModuleGraphFields(result: ModuleGraph) =
   # A module ID of -1 means that the symbol is not attached to a module at all,
   # but to the module graph:
   result.idgen = IdGenerator(module: -1'i32, symId: 0'i32, typeId: 0'i32)
-  initStrTable(result.packageSyms)
+  result.packageSyms = initStrTable()
   result.deps = initIntSet()
   result.importDeps = initTable[FileIndex, seq[FileIndex]]()
   result.ifaces = @[]
   result.importStack = @[]
   result.inclToMod = initTable[FileIndex, FileIndex]()
   result.owners = @[]
-  result.suggestSymbols = initTable[FileIndex, seq[SymInfoPair]]()
+  result.suggestSymbols = initTable[FileIndex, SuggestFileSymbolDatabase]()
   result.suggestErrors = initTable[FileIndex, seq[Suggest]]()
   result.methods = @[]
-  initStrTable(result.compilerprocs)
-  initStrTable(result.exposed)
-  initStrTable(result.packageTypes)
+  result.compilerprocs = initStrTable()
+  result.exposed = initStrTable()
+  result.packageTypes = initStrTable()
   result.emptyNode = newNode(nkEmpty)
   result.cacheSeqs = initTable[string, PNode]()
   result.cacheCounters = initTable[string, BiggestInt]()
@@ -477,6 +515,7 @@ proc initModuleGraphFields(result: ModuleGraph) =
   result.symBodyHashes = initTable[int, SigHash]()
   result.operators = initOperators(result)
   result.emittedTypeInfo = initTable[string, FileIndex]()
+  result.cachedFiles = newStringTable()
 
 proc newModuleGraph*(cache: IdentCache; config: ConfigRef): ModuleGraph =
   result = ModuleGraph()
@@ -485,7 +524,7 @@ proc newModuleGraph*(cache: IdentCache; config: ConfigRef): ModuleGraph =
   initModuleGraphFields(result)
 
 proc resetAllModules*(g: ModuleGraph) =
-  initStrTable(g.packageSyms)
+  g.packageSyms = initStrTable()
   g.deps = initIntSet()
   g.ifaces = @[]
   g.importStack = @[]
@@ -493,11 +532,12 @@ proc resetAllModules*(g: ModuleGraph) =
   g.usageSym = nil
   g.owners = @[]
   g.methods = @[]
-  initStrTable(g.compilerprocs)
-  initStrTable(g.exposed)
+  g.compilerprocs = initStrTable()
+  g.exposed = initStrTable()
   initModuleGraphFields(g)
 
 proc getModule*(g: ModuleGraph; fileIdx: FileIndex): PSym =
+  result = nil
   if fileIdx.int32 >= 0:
     if isCachedModule(g, fileIdx.int32):
       result = g.packed[fileIdx.int32].module
@@ -577,6 +617,7 @@ proc markDirty*(g: ModuleGraph; fileIdx: FileIndex) =
   if m != nil:
     g.suggestSymbols.del(fileIdx)
     g.suggestErrors.del(fileIdx)
+    g.resetForBackend
     incl m.flags, sfDirty
 
 proc unmarkAllDirty*(g: ModuleGraph) =
@@ -603,6 +644,7 @@ proc markClientsDirty*(g: ModuleGraph; fileIdx: FileIndex) =
 
 proc needsCompilation*(g: ModuleGraph): bool =
   # every module that *depends* on this file is also dirty:
+  result = false
   for i in 0i32..<g.ifaces.len.int32:
     let m = g.ifaces[i].module
     if m != nil:
@@ -610,6 +652,7 @@ proc needsCompilation*(g: ModuleGraph): bool =
         return true
 
 proc needsCompilation*(g: ModuleGraph, fileIdx: FileIndex): bool =
+  result = false
   let module = g.getModule(fileIdx)
   if module != nil and g.isDirty(module):
     return true
@@ -631,6 +674,8 @@ proc moduleFromRodFile*(g: ModuleGraph; fileIdx: FileIndex;
   ## Returns 'nil' if the module needs to be recompiled.
   if g.config.symbolFiles in {readOnlySf, v2Sf, stressTest}:
     result = moduleFromRodFile(g.packed, g.config, g.cache, fileIdx, cachedModules)
+  else:
+    result = nil
 
 proc configComplete*(g: ModuleGraph) =
   rememberStartupConfig(g.startupPackedConfig, g.config)
@@ -662,16 +707,14 @@ func belongsToStdlib*(graph: ModuleGraph, sym: PSym): bool =
   ## Check if symbol belongs to the 'stdlib' package.
   sym.getPackageSymbol.getPackageId == graph.systemModule.getPackageId
 
-proc `==`*(a, b: SymInfoPair): bool =
-  result = a.sym == b.sym and a.info.exactEquals(b.info)
-
-proc fileSymbols*(graph: ModuleGraph, fileIdx: FileIndex): seq[SymInfoPair] =
-  result = graph.suggestSymbols.getOrDefault(fileIdx, @[])
+proc fileSymbols*(graph: ModuleGraph, fileIdx: FileIndex): SuggestFileSymbolDatabase =
+  result = graph.suggestSymbols.getOrDefault(fileIdx, newSuggestFileSymbolDatabase(fileIdx, optIdeExceptionInlayHints in graph.config.globalOptions))
+  doAssert(result.fileIndex == fileIdx)
 
 iterator suggestSymbolsIter*(g: ModuleGraph): SymInfoPair =
   for xs in g.suggestSymbols.values:
-    for x in xs:
-      yield x
+    for i in xs.lineInfo.low..xs.lineInfo.high:
+      yield xs.getSymInfoPair(i)
 
 iterator suggestErrorsIter*(g: ModuleGraph): Suggest =
   for xs in g.suggestErrors.values:

compiler/modulepaths.nim

@@ -7,9 +7,11 @@
 #    distribution, for details about the copyright.
 #
 
-import ast, renderer, strutils, msgs, options, idents, os, lineinfos,
+import ast, renderer, msgs, options, idents, lineinfos,
   pathutils
 
+import std/[strutils, os]
+
 proc getModuleName*(conf: ConfigRef; n: PNode): string =
   # This returns a short relative module name without the nim extension
   # e.g. like "system", "importer" or "somepath/module"
@@ -36,11 +38,18 @@ proc getModuleName*(conf: ConfigRef; n: PNode): string =
           localError(n.info, "only '/' supported with $package notation")
           result = ""
     else:
-      let modname = getModuleName(conf, n[2])
-      # hacky way to implement 'x / y /../ z':
-      result = getModuleName(conf, n1)
-      result.add renderTree(n0, {renderNoComments}).replace(" ")
-      result.add modname
+      if n0.kind in nkIdentKinds:
+        let ident = n0.getPIdent
+        if ident != nil and ident.s[0] == '/':
+          let modname = getModuleName(conf, n[2])
+          # hacky way to implement 'x / y /../ z':
+          result = getModuleName(conf, n1)
+          result.add renderTree(n0, {renderNoComments}).replace(" ")
+          result.add modname
+        else:
+          result = ""
+      else:
+        result = ""
   of nkPrefix:
     when false:
       if n[0].kind == nkIdent and n[0].ident.s == "$":

compiler/modules.nim

@@ -14,6 +14,9 @@ import
   idents, lexer, syntaxes, modulegraphs,
   lineinfos, pathutils
 
+import ../dist/checksums/src/checksums/sha1
+import std/strtabs
+
 proc resetSystemArtifacts*(g: ModuleGraph) =
   magicsys.resetSysTypes(g)
 
@@ -42,6 +45,8 @@ proc includeModule*(graph: ModuleGraph; s: PSym, fileIdx: FileIndex): PNode =
   result = syntaxes.parseFile(fileIdx, graph.cache, graph.config)
   graph.addDep(s, fileIdx)
   graph.addIncludeDep(s.position.FileIndex, fileIdx)
+  let path = toFullPath(graph.config, fileIdx)
+  graph.cachedFiles[path] = $secureHashFile(path)
 
 proc wantMainModule*(conf: ConfigRef) =
   if conf.projectFull.isEmpty:

compiler/msgs.nim

@@ -61,14 +61,12 @@ proc makeCString*(s: string): Rope =
   result.add('\"')
 
 proc newFileInfo(fullPath: AbsoluteFile, projPath: RelativeFile): TFileInfo =
-  result.fullPath = fullPath
-  #shallow(result.fullPath)
-  result.projPath = projPath
-  #shallow(result.projPath)
-  result.shortName = fullPath.extractFilename
+  result = TFileInfo(fullPath: fullPath, projPath: projPath,
+                    shortName: fullPath.extractFilename,
+                    quotedFullName: fullPath.string.makeCString,
+                    lines: @[]
+  )
   result.quotedName = result.shortName.makeCString
-  result.quotedFullName = fullPath.string.makeCString
-  result.lines = @[]
   when defined(nimpretty):
     if not result.fullPath.isEmpty:
       try:
@@ -125,18 +123,18 @@ proc fileInfoIdx*(conf: ConfigRef; filename: AbsoluteFile; isKnownFile: var bool
     conf.m.filenameToIndexTbl[canon2] = result
 
 proc fileInfoIdx*(conf: ConfigRef; filename: AbsoluteFile): FileIndex =
-  var dummy: bool
+  var dummy: bool = false
   result = fileInfoIdx(conf, filename, dummy)
 
 proc fileInfoIdx*(conf: ConfigRef; filename: RelativeFile; isKnownFile: var bool): FileIndex =
   fileInfoIdx(conf, AbsoluteFile expandFilename(filename.string), isKnownFile)
 
 proc fileInfoIdx*(conf: ConfigRef; filename: RelativeFile): FileIndex =
-  var dummy: bool
+  var dummy: bool = false
   fileInfoIdx(conf, AbsoluteFile expandFilename(filename.string), dummy)
 
 proc newLineInfo*(fileInfoIdx: FileIndex, line, col: int): TLineInfo =
-  result.fileIndex = fileInfoIdx
+  result = TLineInfo(fileIndex: fileInfoIdx)
   if line < int high(uint16):
     result.line = uint16(line)
   else:
@@ -226,7 +224,7 @@ proc setDirtyFile*(conf: ConfigRef; fileIdx: FileIndex; filename: AbsoluteFile)
 
 proc setHash*(conf: ConfigRef; fileIdx: FileIndex; hash: string) =
   assert fileIdx.int32 >= 0
-  when defined(gcArc) or defined(gcOrc):
+  when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc):
     conf.m.fileInfos[fileIdx.int32].hash = hash
   else:
     shallowCopy(conf.m.fileInfos[fileIdx.int32].hash, hash)
@@ -234,7 +232,7 @@ proc setHash*(conf: ConfigRef; fileIdx: FileIndex; hash: string) =
 
 proc getHash*(conf: ConfigRef; fileIdx: FileIndex): string =
   assert fileIdx.int32 >= 0
-  when defined(gcArc) or defined(gcOrc):
+  when defined(gcArc) or defined(gcOrc) or defined(gcAtomicArc):
     result = conf.m.fileInfos[fileIdx.int32].hash
   else:
     shallowCopy(result, conf.m.fileInfos[fileIdx.int32].hash)
@@ -294,9 +292,11 @@ proc toColumn*(info: TLineInfo): int {.inline.} =
   result = info.col
 
 proc toFileLineCol(info: InstantiationInfo): string {.inline.} =
+  result = ""
   result.toLocation(info.filename, info.line, info.column + ColOffset)
 
 proc toFileLineCol*(conf: ConfigRef; info: TLineInfo): string {.inline.} =
+  result = ""
   result.toLocation(toMsgFilename(conf, info), info.line.int, info.col.int + ColOffset)
 
 proc `$`*(conf: ConfigRef; info: TLineInfo): string = toFileLineCol(conf, info)
@@ -408,7 +408,7 @@ proc getMessageStr(msg: TMsgKind, arg: string): string = msgKindToString(msg) %
 type TErrorHandling* = enum doNothing, doAbort, doRaise
 
 proc log*(s: string) =
-  var f: File
+  var f: File = default(File)
   if open(f, getHomeDir() / "nimsuggest.log", fmAppend):
     f.writeLine(s)
     close(f)
@@ -429,7 +429,8 @@ To create a stacktrace, rerun compilation with './koch temp $1 <file>', see $2 f
 proc handleError(conf: ConfigRef; msg: TMsgKind, eh: TErrorHandling, s: string, ignoreMsg: bool) =
   if msg in fatalMsgs:
     if conf.cmd == cmdIdeTools: log(s)
-    quit(conf, msg)
+    if conf.cmd != cmdIdeTools or msg != errFatal:
+      quit(conf, msg)
   if msg >= errMin and msg <= errMax or
       (msg in warnMin..hintMax and msg in conf.warningAsErrors and not ignoreMsg):
     inc(conf.errorCounter)
@@ -437,7 +438,11 @@ proc handleError(conf: ConfigRef; msg: TMsgKind, eh: TErrorHandling, s: string,
     if conf.errorCounter >= conf.errorMax:
       # only really quit when we're not in the new 'nim check --def' mode:
       if conf.ideCmd == ideNone:
-        quit(conf, msg)
+        when defined(nimsuggest):
+          #we need to inform the user that something went wrong when initializing NimSuggest
+          raiseRecoverableError(s)
+        else:
+          quit(conf, msg)
     elif eh == doAbort and conf.cmd != cmdIdeTools:
       quit(conf, msg)
     elif eh == doRaise:
@@ -502,6 +507,8 @@ proc getSurroundingSrc(conf: ConfigRef; info: TLineInfo): string =
     result = "\n" & indent & $sourceLine(conf, info)
     if info.col >= 0:
       result.add "\n" & indent & spaces(info.col) & '^'
+  else:
+    result = ""
 
 proc formatMsg*(conf: ConfigRef; info: TLineInfo, msg: TMsgKind, arg: string): string =
   let title = case msg
@@ -511,7 +518,8 @@ proc formatMsg*(conf: ConfigRef; info: TLineInfo, msg: TMsgKind, arg: string): s
   conf.toFileLineCol(info) & " " & title & getMessageStr(msg, arg)
 
 proc liMessage*(conf: ConfigRef; info: TLineInfo, msg: TMsgKind, arg: string,
-               eh: TErrorHandling, info2: InstantiationInfo, isRaw = false) {.gcsafe, noinline.} =
+               eh: TErrorHandling, info2: InstantiationInfo, isRaw = false,
+               ignoreError = false) {.gcsafe, noinline.} =
   var
     title: string
     color: ForegroundColor
@@ -552,9 +560,10 @@ proc liMessage*(conf: ConfigRef; info: TLineInfo, msg: TMsgKind, arg: string,
     ignoreMsg = not conf.hasHint(msg)
     if not ignoreMsg and msg in conf.warningAsErrors:
       title = ErrorTitle
+      color = ErrorColor
     else:
       title = HintTitle
-    color = HintColor
+      color = HintColor
     inc(conf.hintCounter)
 
   let s = if isRaw: arg else: getMessageStr(msg, arg)
@@ -576,7 +585,8 @@ proc liMessage*(conf: ConfigRef; info: TLineInfo, msg: TMsgKind, arg: string,
             " compiler msg initiated here", KindColor,
             KindFormat % $hintMsgOrigin,
             resetStyle, conf.unitSep)
-  handleError(conf, msg, eh, s, ignoreMsg)
+  if not ignoreError:
+    handleError(conf, msg, eh, s, ignoreMsg)
   if msg in fatalMsgs:
     # most likely would have died here but just in case, we restore state
     conf.m.errorOutputs = errorOutputsOld
@@ -641,13 +651,16 @@ template lintReport*(conf: ConfigRef; info: TLineInfo, beau, got: string, extraM
   let msg = if optStyleError in conf.globalOptions: errGenerated else: hintName
   liMessage(conf, info, msg, m, doNothing, instLoc())
 
-proc quotedFilename*(conf: ConfigRef; i: TLineInfo): Rope =
-  if i.fileIndex.int32 < 0:
+proc quotedFilename*(conf: ConfigRef; fi: FileIndex): Rope =
+  if fi.int32 < 0:
     result = makeCString "???"
   elif optExcessiveStackTrace in conf.globalOptions:
-    result = conf.m.fileInfos[i.fileIndex.int32].quotedFullName
+    result = conf.m.fileInfos[fi.int32].quotedFullName
   else:
-    result = conf.m.fileInfos[i.fileIndex.int32].quotedName
+    result = conf.m.fileInfos[fi.int32].quotedName
+
+proc quotedFilename*(conf: ConfigRef; i: TLineInfo): Rope =
+  quotedFilename(conf, i.fileIndex)
 
 template listMsg(title, r) =
   msgWriteln(conf, title, {msgNoUnitSep})
@@ -719,6 +732,8 @@ proc genSuccessX*(conf: ConfigRef) =
   elif conf.outFile.isEmpty and conf.cmd notin {cmdJsonscript} + cmdDocLike + cmdBackends:
     # for some cmd we expect a valid absOutFile
     output = "unknownOutput"
+  elif optStdout in conf.globalOptions:
+    output = "stdout"
   else:
     output = $conf.absOutFile
   if conf.filenameOption != foAbs: output = output.AbsoluteFile.extractFilename

compiler/nilcheck.nim

@@ -7,8 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
-import ast, renderer, intsets, tables, msgs, options, lineinfos, strformat, idents, treetab, hashes
-import sequtils, strutils, sets
+import ast, renderer, msgs, options, lineinfos, idents, treetab
+import std/[intsets, tables, sequtils, strutils, sets, strformat, hashes]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -309,6 +309,7 @@ proc symbol(n: PNode): Symbol =
   # echo "symbol ", n, " ", n.kind, " ", result.int
 
 func `$`(map: NilMap): string =
+  result = ""
   var now = map
   var stack: seq[NilMap] = @[]
   while not now.isNil:
@@ -416,7 +417,7 @@ proc moveOut(ctx: NilCheckerContext, map: NilMap, target: PNode) =
   if targetSetIndex != noSetIndex:
     var targetSet = map.sets[targetSetIndex]
     if targetSet.len > 1:
-      var other: ExprIndex
+      var other: ExprIndex = default(ExprIndex)
 
       for element in targetSet:
         if element.ExprIndex != targetIndex:
@@ -497,7 +498,7 @@ proc checkCall(n, ctx, map): Check =
   # check args and handle possible mutations
 
   var isNew = false
-  result.map = map
+  result = Check(map: map)
   for i, child in n:
     discard check(child, ctx, map)
 
@@ -506,7 +507,7 @@ proc checkCall(n, ctx, map): Check =
       # as it might have been mutated
       # TODO similar for normal refs and fields: find dependent exprs: brackets
 
-      if child.kind == nkHiddenAddr and not child.typ.isNil and child.typ.kind == tyVar and child.typ[0].kind == tyRef:
+      if child.kind == nkHiddenAddr and not child.typ.isNil and child.typ.kind == tyVar and child.typ.elementType.kind == tyRef:
         if not isNew:
           result.map = newNilMap(map)
           isNew = true
@@ -561,7 +562,7 @@ proc derefWarning(n, ctx, map; kind: Nilability) =
   if n.info in ctx.warningLocations:
     return
   ctx.warningLocations.incl(n.info)
-  var a: seq[History]
+  var a: seq[History] = @[]
   if n.kind == nkSym:
     a = history(map, ctx.index(n))
   var res = ""
@@ -752,6 +753,7 @@ proc checkReturn(n, ctx, map): Check =
 
 proc checkIf(n, ctx, map): Check =
   ## check branches based on condition
+  result = default(Check)
   var mapIf: NilMap = map
 
   # first visit the condition
@@ -765,7 +767,7 @@ proc checkIf(n, ctx, map): Check =
   # the state of the conditions: negating conditions before the current one
   var layerHistory = newNilMap(mapIf)
   # the state after branch effects
-  var afterLayer: NilMap
+  var afterLayer: NilMap = nil
   # the result nilability for expressions
   var nilability = Safe
 
@@ -824,7 +826,7 @@ proc checkFor(n, ctx, map): Check =
   var check2 = check(n.sons[2], ctx, m)
   var map2 = check2.map
 
-  result.map = ctx.union(map0, m)
+  result = Check(map: ctx.union(map0, m))
   result.map = ctx.union(result.map, map2)
   result.nilability = Safe
 
@@ -852,7 +854,7 @@ proc checkWhile(n, ctx, map): Check =
   var check2 = check(n.sons[1], ctx, m)
   var map2 = check2.map
 
-  result.map = ctx.union(map0, map1)
+  result = Check(map: ctx.union(map0, map1))
   result.map = ctx.union(result.map, map2)
   result.nilability = Safe
 
@@ -862,9 +864,10 @@ proc checkInfix(n, ctx, map): Check =
   ##   a or b : map is an union of a and b's
   ##   a == b : use checkCondition
   ##   else: no change, just check args
+  result = default(Check)
   if n[0].kind == nkSym:
-    var mapL: NilMap
-    var mapR: NilMap
+    var mapL: NilMap = nil
+    var mapR: NilMap = nil
     if n[0].sym.magic notin {mAnd, mEqRef}:
       mapL = checkCondition(n[1], ctx, map, false, false)
       mapR = checkCondition(n[2], ctx, map, false, false)
@@ -897,7 +900,7 @@ proc checkInfix(n, ctx, map): Check =
 proc checkIsNil(n, ctx, map; isElse: bool = false): Check =
   ## check isNil calls
   ## update the map depending on if it is not isNil or isNil
-  result.map = newNilMap(map)
+  result = Check(map: newNilMap(map))
   let value = n[1]
   result.map.store(ctx, ctx.index(n[1]), if not isElse: Nil else: Safe, TArg, n.info, n)
 
@@ -909,24 +912,24 @@ proc infix(ctx: NilCheckerContext, l: PNode, r: PNode, magic: TMagic): PNode =
     else: ""
 
   var cache = newIdentCache()
-  var op = newSym(skVar, cache.getIdent(name), nextSymId ctx.idgen, nil, r.info)
+  var op = newSym(skVar, cache.getIdent(name), ctx.idgen, nil, r.info)
 
   op.magic = magic
   result = nkInfix.newTree(
     newSymNode(op, r.info),
     l,
     r)
-  result.typ = newType(tyBool, nextTypeId ctx.idgen, nil)
+  result.typ = newType(tyBool, ctx.idgen, nil)
 
 proc prefixNot(ctx: NilCheckerContext, node: PNode): PNode =
   var cache = newIdentCache()
-  var op = newSym(skVar, cache.getIdent("not"), nextSymId ctx.idgen, nil, node.info)
+  var op = newSym(skVar, cache.getIdent("not"), ctx.idgen, nil, node.info)
 
   op.magic = mNot
   result = nkPrefix.newTree(
     newSymNode(op, node.info),
     node)
-  result.typ = newType(tyBool, nextTypeId ctx.idgen, nil)
+  result.typ = newType(tyBool, ctx.idgen, nil)
 
 proc infixEq(ctx: NilCheckerContext, l: PNode, r: PNode): PNode =
   infix(ctx, l, r, mEqRef)
@@ -945,9 +948,9 @@ proc checkCase(n, ctx, map): Check =
   #   c2
   # also a == true is a , a == false is not a
   let base = n[0]
-  result.map = map.copyMap()
+  result = Check(map: map.copyMap())
   result.nilability = Safe
-  var a: PNode
+  var a: PNode = nil
   for child in n:
     case child.kind:
     of nkOfBranch:
@@ -1217,12 +1220,12 @@ proc check(n: PNode, ctx: NilCheckerContext, map: NilMap): Check =
     result = check(n.sons[1], ctx, map)
   of nkStmtList, nkStmtListExpr, nkChckRangeF, nkChckRange64, nkChckRange,
      nkBracket, nkCurly, nkPar, nkTupleConstr, nkClosure, nkObjConstr, nkElse:
-    result.map = map
+    result = Check(map: map)
     if n.kind in {nkObjConstr, nkTupleConstr}:
       # TODO deeper nested elements?
       # A(field: B()) #
       # field: Safe ->
-      var elements: seq[(PNode, Nilability)]
+      var elements: seq[(PNode, Nilability)] = @[]
       for i, child in n:
         result = check(child, ctx, result.map)
         if i > 0:
@@ -1244,10 +1247,10 @@ proc check(n: PNode, ctx: NilCheckerContext, map: NilMap): Check =
     result = checkIf(n, ctx, map)
   of nkAsgn, nkFastAsgn, nkSinkAsgn:
     result = checkAsgn(n[0], n[1], ctx, map)
-  of nkVarSection:
-    result.map = map
+  of nkVarSection, nkLetSection:
+    result = Check(map: map)
     for child in n:
-      result = checkAsgn(child[0], child[2], ctx, result.map)
+      result = checkAsgn(child[0].skipPragmaExpr, child[2], ctx, result.map)
   of nkForStmt:
     result = checkFor(n, ctx, map)
   of nkCaseStmt:
@@ -1271,8 +1274,7 @@ proc check(n: PNode, ctx: NilCheckerContext, map: NilMap): Check =
   else:
 
     var elementMap = map.copyMap()
-    var elementCheck: Check
-    elementCheck.map = elementMap
+    var elementCheck = Check(map: elementMap)
     for element in n:
       elementCheck = check(element, ctx, elementCheck.map)
 
@@ -1333,7 +1335,7 @@ proc preVisit(ctx: NilCheckerContext, s: PSym, body: PNode, conf: ConfigRef) =
   ctx.symbolIndices = {resultId: resultExprIndex}.toTable()
   var cache = newIdentCache()
   ctx.expressions = SeqOfDistinct[ExprIndex, PNode](@[newIdentNode(cache.getIdent("result"), s.ast.info)])
-  var emptySet: IntSet # set[ExprIndex]
+  var emptySet: IntSet = initIntSet() # set[ExprIndex]
   ctx.dependants = SeqOfDistinct[ExprIndex, IntSet](@[emptySet])
   for i, arg in s.typ.n.sons:
     if i > 0:
@@ -1365,7 +1367,7 @@ proc checkNil*(s: PSym; body: PNode; conf: ConfigRef, idgen: IdGenerator) =
         continue
       map.store(context, context.index(child), typeNilability(child.typ), TArg, child.info, child)
 
-  map.store(context, resultExprIndex, if not s.typ[0].isNil and s.typ[0].kind == tyRef: Nil else: Safe, TResult, s.ast.info)
+  map.store(context, resultExprIndex, if not s.typ.returnType.isNil and s.typ.returnType.kind == tyRef: Nil else: Safe, TResult, s.ast.info)
 
   # echo "checking ", s.name.s, " ", filename
 
@@ -1381,5 +1383,5 @@ proc checkNil*(s: PSym; body: PNode; conf: ConfigRef, idgen: IdGenerator) =
   # (ANotNil, BNotNil) :
   # do we check on asgn nilability at all?
 
-  if not s.typ[0].isNil and s.typ[0].kind == tyRef and tfNotNil in s.typ[0].flags:
+  if not s.typ.returnType.isNil and s.typ.returnType.kind == tyRef and tfNotNil in s.typ.returnType.flags:
     checkResult(s.ast, context, res.map)

compiler/nim.cfg

@@ -7,14 +7,15 @@ define:nimcore
 define:nimPreviewFloatRoundtrip
 define:nimPreviewSlimSystem
 define:nimPreviewCstringConversion
+define:nimPreviewProcConversion
 define:nimPreviewRangeDefault
+define:nimPreviewNonVarDestructor
 threads:off
 
 #import:"$projectpath/testability"
 
 @if windows:
   cincludes: "$lib/wrappers/libffi/common"
-  tlsEmulation:off
 @end
 
 define:useStdoutAsStdmsg
@@ -31,9 +32,6 @@ define:useStdoutAsStdmsg
   warning[ObservableStores]:off
 @end
 
-@if nimHasWarnCastSizes:
-  warning[CastSizes]:on
-@end
 
 @if nimHasWarningAsError:
   warningAsError[GcUnsafe2]:on
@@ -44,5 +42,22 @@ define:useStdoutAsStdmsg
 @end
 
 @if nimHasWarnBareExcept:
+  warning[BareExcept]:on
   warningAserror[BareExcept]:on
 @end
+
+
+@if nimUseStrictDefs:
+  experimental:strictDefs
+  warningAsError[Uninit]:on
+  warningAsError[ProveInit]:on
+@end
+
+@if nimHasWarnStdPrefix:
+  warning[StdPrefix]:on
+  warningAsError[StdPrefix]:on
+@end
+
+@if nimHasVtables:
+  experimental:vtables
+@end

compiler/nim.nim

@@ -12,10 +12,7 @@ import std/[os, strutils, parseopt]
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
-when defined(windows) and not defined(nimKochBootstrap):
-  # remove workaround pending bootstrap >= 1.5.1
-  # refs https://github.com/nim-lang/Nim/issues/18334#issuecomment-867114536
-  # alternative would be to prepend `currentSourcePath.parentDir.quoteShell`
+when defined(windows):
   when defined(gcc):
     when defined(x86):
       {.link: "../icons/nim.res".}
@@ -31,7 +28,7 @@ import
   commands, options, msgs, extccomp, main, idents, lineinfos, cmdlinehelper,
   pathutils, modulegraphs
 
-from browsers import openDefaultBrowser
+from std/browsers import openDefaultBrowser
 from nodejs import findNodeJs
 
 when hasTinyCBackend:
@@ -94,6 +91,9 @@ proc getNimRunExe(conf: ConfigRef): string =
   if conf.isDefined("mingw"):
     if conf.isDefined("i386"): result = "wine"
     elif conf.isDefined("amd64"): result = "wine64"
+    else: result = ""
+  else:
+    result = ""
 
 proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
   let self = NimProg(
@@ -116,7 +116,9 @@ proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
     conf.backend = backendC
 
   if conf.selectedGC == gcUnselected:
-    if conf.backend in {backendC, backendCpp, backendObjc}:
+    if conf.backend in {backendC, backendCpp, backendObjc, backendNir} or
+        (conf.cmd == cmdInteractive and isDefined(conf, "nir")) or
+        (conf.cmd in cmdDocLike and conf.backend != backendJs):
       initOrcDefines(conf)
 
   mainCommand(graph)
@@ -140,7 +142,7 @@ proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
         # tasyncjs_fail` would fail, refs https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode
         if cmdPrefix.len == 0: cmdPrefix = findNodeJs().quoteShell
         cmdPrefix.add " --unhandled-rejections=strict"
-      else: doAssert false, $conf.backend
+      else: raiseAssert $conf.backend
       if cmdPrefix.len > 0: cmdPrefix.add " "
         # without the `cmdPrefix.len > 0` check, on windows you'd get a cryptic:
         # `The parameter is incorrect`

compiler/nimblecmd.nim

@@ -9,12 +9,15 @@
 
 ## Implements some helper procs for Nimble (Nim's package manager) support.
 
-import parseutils, strutils, os, options, msgs, sequtils, lineinfos, pathutils,
-  std/sha1, tables
+import options, msgs, lineinfos, pathutils
+
+import std/[parseutils, strutils, os, tables, sequtils]
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions]
 
+import ../dist/checksums/src/checksums/sha1
+
 proc addPath*(conf: ConfigRef; path: AbsoluteDir, info: TLineInfo) =
   if not conf.searchPaths.contains(path):
     conf.searchPaths.insert(path, 0)
@@ -35,11 +38,16 @@ proc isSpecial(ver: Version): bool =
 
 proc isValidVersion(v: string): bool =
   if v.len > 0:
-    if v[0] in {'#'} + Digits: return true
+    if v[0] in {'#'} + Digits:
+      result = true
+    else:
+      result = false
+  else:
+    result = false
 
 proc `<`*(ver: Version, ver2: Version): bool =
   ## This is synced from Nimble's version module.
-
+  result = false
   # Handling for special versions such as "#head" or "#branch".
   if ver.isSpecial or ver2.isSpecial:
     if ver2.isSpecial and ($ver2).normalize == "#head":
@@ -71,6 +79,8 @@ proc getPathVersionChecksum*(p: string): tuple[name, version, checksum: string]
   ## ``/home/user/.nimble/pkgs/package-0.1-febadeaea2345e777f0f6f8433f7f0a52edd5d1b`` into
   ## ``("/home/user/.nimble/pkgs/package", "0.1", "febadeaea2345e777f0f6f8433f7f0a52edd5d1b")``
 
+  result = ("", "", "")
+
   const checksumSeparator = '-'
   const versionSeparator = '-'
   const specialVersionSepartator = "-#"
@@ -143,7 +153,7 @@ proc addNimblePath(conf: ConfigRef; p: string, info: TLineInfo) =
     conf.lazyPaths.insert(AbsoluteDir path, 0)
 
 proc addPathRec(conf: ConfigRef; dir: string, info: TLineInfo) =
-  var packages: PackageInfo
+  var packages: PackageInfo = initTable[string, tuple[version, checksum: string]]()
   var pos = dir.len-1
   if dir[pos] in {DirSep, AltSep}: inc(pos)
   for k,p in os.walkDir(dir):

compiler/nimconf.nim

@@ -10,8 +10,10 @@
 # This module handles the reading of the config file.
 
 import
-  llstream, commands, os, strutils, msgs, lexer, ast,
-  options, idents, wordrecg, strtabs, lineinfos, pathutils, scriptconfig
+  llstream, commands, msgs, lexer, ast,
+  options, idents, wordrecg, lineinfos, pathutils, scriptconfig
+
+import std/[os, strutils, strtabs]
 
 when defined(nimPreviewSlimSystem):
   import std/syncio
@@ -162,7 +164,7 @@ proc checkSymbol(L: Lexer, tok: Token) =
     lexMessage(L, errGenerated, "expected identifier, but got: " & $tok)
 
 proc parseAssignment(L: var Lexer, tok: var Token;
-                     config: ConfigRef; condStack: var seq[bool]) =
+                     config: ConfigRef; filename: AbsoluteFile; condStack: var seq[bool]) =
   if tok.ident != nil:
     if tok.ident.s == "-" or tok.ident.s == "--":
       confTok(L, tok, config, condStack)           # skip unnecessary prefix
@@ -205,6 +207,7 @@ proc parseAssignment(L: var Lexer, tok: var Token;
       checkSymbol(L, tok)
       val.add($tok)
       confTok(L, tok, config, condStack)
+  config.currentConfigDir = parentDir(filename.string)
   if percent:
     processSwitch(s, strtabs.`%`(val, config.configVars,
                                 {useEnvironment, useEmpty}), passPP, info, config)
@@ -214,20 +217,21 @@ proc parseAssignment(L: var Lexer, tok: var Token;
 proc readConfigFile*(filename: AbsoluteFile; cache: IdentCache;
                     config: ConfigRef): bool =
   var
-    L: Lexer
+    L: Lexer = default(Lexer)
     tok: Token
     stream: PLLStream
   stream = llStreamOpen(filename, fmRead)
   if stream != nil:
-    initToken(tok)
     openLexer(L, filename, stream, cache, config)
-    tok.tokType = tkEof       # to avoid a pointless warning
+    tok = Token(tokType: tkEof)       # to avoid a pointless warning
     var condStack: seq[bool] = @[]
     confTok(L, tok, config, condStack)           # read in the first token
-    while tok.tokType != tkEof: parseAssignment(L, tok, config, condStack)
+    while tok.tokType != tkEof: parseAssignment(L, tok, config, filename, condStack)
     if condStack.len > 0: lexMessage(L, errGenerated, "expected @end")
     closeLexer(L)
     return true
+  else:
+    result = false
 
 proc getUserConfigPath*(filename: RelativeFile): AbsoluteFile =
   result = getConfigDir().AbsoluteDir / RelativeDir"nim" / filename
@@ -250,7 +254,7 @@ proc loadConfigs*(cfg: RelativeFile; cache: IdentCache; conf: ConfigRef; idgen:
 
   template runNimScriptIfExists(path: AbsoluteFile, isMain = false) =
     let p = path # eval once
-    var s: PLLStream
+    var s: PLLStream = nil
     if isMain and optWasNimscript in conf.globalOptions:
       if conf.projectIsStdin: s = stdin.llStreamOpen
       elif conf.projectIsCmd: s = llStreamOpen(conf.cmdInput)

compiler/nimeval.nim

@@ -11,8 +11,8 @@
 import
   ast, modules, condsyms,
   options, llstream, lineinfos, vm,
-  vmdef, modulegraphs, idents, os, pathutils,
-  scriptconfig, std/compilesettings
+  vmdef, modulegraphs, idents, pathutils,
+  scriptconfig, std/[compilesettings, tables, os]
 
 import pipelines
 
@@ -40,7 +40,7 @@ proc selectUniqueSymbol*(i: Interpreter; name: string;
   assert i != nil
   assert i.mainModule != nil, "no main module selected"
   let n = getIdent(i.graph.cache, name)
-  var it: ModuleIter
+  var it: ModuleIter = default(ModuleIter)
   var s = initModuleIter(it, i.graph, i.mainModule, n)
   result = nil
   while s != nil:
@@ -78,6 +78,9 @@ proc evalScript*(i: Interpreter; scriptStream: PLLStream = nil) =
   assert i != nil
   assert i.mainModule != nil, "no main module selected"
   initStrTables(i.graph, i.mainModule)
+  i.graph.cacheSeqs.clear()
+  i.graph.cacheCounters.clear()
+  i.graph.cacheTables.clear()
   i.mainModule.ast = nil
 
   let s = if scriptStream != nil: scriptStream

compiler/nimfix/nimfix.nim

@@ -1,111 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2015 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-## Nimfix is a tool that helps to convert old-style Nimrod code to Nim code.
-
-import strutils, os, parseopt
-import compiler/[options, commands, modules, sem,
-  passes, passaux, linter,
-  msgs, nimconf,
-  extccomp, condsyms,
-  modulegraphs, idents]
-
-const Usage = """
-Nimfix - Tool to patch Nim code
-Usage:
-  nimfix [options] projectfile.nim
-
-Options:
-  --overwriteFiles:on|off          overwrite the original nim files.
-                                   DEFAULT is ON!
-  --wholeProject                   overwrite every processed file.
-  --checkExtern:on|off             style check also extern names
-  --styleCheck:on|off|auto         performs style checking for identifiers
-                                   and suggests an alternative spelling;
-                                   'auto' corrects the spelling.
-  --bestEffort                     try to fix the code even when there
-                                   are errors.
-
-In addition, all command line options of Nim are supported.
-"""
-
-proc mainCommand =
-  registerPass verbosePass
-  registerPass semPass
-  conf.setCmd cmdNimfix
-  searchPaths.add options.libpath
-  if gProjectFull.len != 0:
-    # current path is always looked first for modules
-    searchPaths.insert(gProjectPath, 0)
-
-  compileProject(newModuleGraph(), newIdentCache())
-  pretty.overwriteFiles()
-
-proc processCmdLine*(pass: TCmdLinePass, cmd: string, config: ConfigRef) =
-  var p = parseopt.initOptParser(cmd)
-  var argsCount = 0
-  gOnlyMainfile = true
-  while true:
-    parseopt.next(p)
-    case p.kind
-    of cmdEnd: break
-    of cmdLongoption, cmdShortOption:
-      case p.key.normalize
-      of "overwritefiles":
-        case p.val.normalize
-        of "on": gOverWrite = true
-        of "off": gOverWrite = false
-        else: localError(gCmdLineInfo, errOnOrOffExpected)
-      of "checkextern":
-        case p.val.normalize
-        of "on": gCheckExtern = true
-        of "off": gCheckExtern = false
-        else: localError(gCmdLineInfo, errOnOrOffExpected)
-      of "stylecheck":
-        case p.val.normalize
-        of "off": gStyleCheck = StyleCheck.None
-        of "on": gStyleCheck = StyleCheck.Warn
-        of "auto": gStyleCheck = StyleCheck.Auto
-        else: localError(gCmdLineInfo, errOnOrOffExpected)
-      of "wholeproject": gOnlyMainfile = false
-      of "besteffort": msgs.gErrorMax = high(int) # don't stop after first error
-      else:
-        processSwitch(pass, p, config)
-    of cmdArgument:
-      options.gProjectName = unixToNativePath(p.key)
-      # if processArgument(pass, p, argsCount): break
-
-proc handleCmdLine(config: ConfigRef) =
-  if paramCount() == 0:
-    stdout.writeLine(Usage)
-  else:
-    processCmdLine(passCmd1, "", config)
-    if gProjectName != "":
-      try:
-        gProjectFull = canonicalizePath(gProjectName)
-      except OSError:
-        gProjectFull = gProjectName
-      var p = splitFile(gProjectFull)
-      gProjectPath = p.dir
-      gProjectName = p.name
-    else:
-      gProjectPath = getCurrentDir()
-    loadConfigs(DefaultConfig, config) # load all config files
-    # now process command line arguments again, because some options in the
-    # command line can overwrite the config file's settings
-    extccomp.initVars()
-    processCmdLine(passCmd2, "", config)
-    mainCommand()
-
-when compileOption("gc", "refc"):
-  GC_disableMarkAndSweep()
-
-condsyms.initDefines()
-defineSymbol "nimfix"
-handleCmdline newConfigRef()

compiler/nimfix/nimfix.nim.cfg

@@ -1,17 +0,0 @@
-# Special configuration file for the Nim project
-# gc:markAndSweep
-
-hint[XDeclaredButNotUsed]:off
-path:"$projectPath/.."
-
-path:"$lib/packages/docutils"
-path:"$nim"
-
-define:useStdoutAsStdmsg
-symbol:nimfix
-define:nimfix
-
-cs:partial
-#define:useNodeIds
-define:booting
-define:noDocgen

compiler/nimfix/prettybase.nim

@@ -1,45 +0,0 @@
-#
-#
-#           The Nim Compiler
-#        (c) Copyright 2015 Andreas Rumpf
-#
-#    See the file "copying.txt", included in this
-#    distribution, for details about the copyright.
-#
-
-import strutils except Letters
-import ".." / [ast, msgs, lineinfos, idents, options, linter]
-
-proc replaceDeprecated*(conf: ConfigRef; info: TLineInfo; oldSym, newSym: PIdent) =
-  let line = sourceLine(conf, info)
-  var first = min(info.col.int, line.len)
-  if first < 0: return
-  #inc first, skipIgnoreCase(line, "proc ", first)
-  while first > 0 and line[first-1] in Letters: dec first
-  if first < 0: return
-  if line[first] == '`': inc first
-
-  let last = first+identLen(line, first)-1
-  if cmpIgnoreStyle(line[first..last], oldSym.s) == 0:
-    var x = line.substr(0, first-1) & newSym.s & line.substr(last+1)
-    when defined(gcArc) or defined(gcOrc):
-      conf.m.fileInfos[info.fileIndex.int32].lines[info.line.int-1] = move x
-    else:
-      system.shallowCopy(conf.m.fileInfos[info.fileIndex.int32].lines[info.line.int-1], x)
-    conf.m.fileInfos[info.fileIndex.int32].dirty = true
-    #if newSym.s == "File": writeStackTrace()
-
-proc replaceDeprecated*(conf: ConfigRef; info: TLineInfo; oldSym, newSym: PSym) =
-  replaceDeprecated(conf, info, oldSym.name, newSym.name)
-
-proc replaceComment*(conf: ConfigRef; info: TLineInfo) =
-  let line = sourceLine(conf, info)
-  var first = info.col.int
-  if line[first] != '#': inc first
-
-  var x = line.substr(0, first-1) & "discard " & line.substr(first+1).escape
-  when defined(gcArc) or defined(gcOrc):
-    conf.m.fileInfos[info.fileIndex.int32].lines[info.line.int-1] = move x
-  else:
-    system.shallowCopy(conf.m.fileInfos[info.fileIndex.int32].lines[info.line.int-1], x)
-  conf.m.fileInfos[info.fileIndex.int32].dirty = true

compiler/nimlexbase.nim

@@ -12,8 +12,9 @@
 # handling that exists! Only at line endings checks are necessary
 # if the buffer needs refilling.
 
-import
-  llstream, strutils
+import llstream
+
+import std/strutils
 
 when defined(nimPreviewSlimSystem):
   import std/assertions