merge upstream code

follow up https://github.com/nim-lang/Nim/pull/11955

.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 +1,23 @@
+# See https://github.com/juancarlospaco/nimrun-action/issues/3#issuecomment-1607344901
+name: issue comments bisects
+on:
+  issue_comment:
+    types: created
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+
+    # nimrun-action requires Nim installed.
+    - uses: jiro4989/setup-nim-action@v1
+      with:
+        nim-version: 'devel'
+
+    - name: Install Dependencies
+      run: sudo apt-get install --no-install-recommends -yq valgrind
+
+    - uses: juancarlospaco/nimrun-action@nim
+      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: ${{ matrix.os }}
+    timeout-minutes: 60 # refs bug #18178
+    steps:
+      - name: 'Checkout'
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 2
+
+      - name: 'Install node.js 16.x'
+        uses: actions/setup-node@v3
+        with:
+          node-version: '16.x'
+
+      - name: 'Install dependencies (Linux amd64)'
+        if: runner.os == 'Linux' && matrix.cpu == 'amd64'
+        run: |
+          sudo apt-fast update -qq
+          DEBIAN_FRONTEND='noninteractive' \
+            sudo apt-fast install --no-install-recommends -yq \
+              libcurl4-openssl-dev libgc-dev libsdl1.2-dev libsfml-dev \
+              valgrind libc6-dbg libblas-dev xorg-dev
+
+      - name: 'Add build binaries to PATH'
+        shell: bash
+        run: echo "${{ 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'
@@ -55,7 +53,7 @@ jobs:
 
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 2
 

.github/workflows/ci_packages.yml

@@ -28,7 +28,7 @@ jobs:
       NIM_TESTAMENT_BATCH: ${{ matrix.batch }}
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 2
 

.github/workflows/ci_publish.yml

@@ -17,7 +17,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 2
 

.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@v8
+        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

@@ -23,11 +23,11 @@ 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'
         CPU: amd64

changelog.md

@@ -10,7 +10,9 @@
 
 
 [//]: # "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 `hasDefaultValue` to `std/typetraits` to check if a type has a valid default value.
 
 [//]: # "Deprecations:"
 
@@ -25,7 +27,7 @@
 ## Compiler changes
 
 
-
-
 ## 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 fullfill its promises.
+
+- The `{.this.}` pragma, deprecated since 0.19, has been removed.
+- `nil` literals can no longer be directly assigned to variables or fields of `distinct` pointer types. They must be converted instead.
+  ```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 =
+    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

@@ -114,6 +114,8 @@ 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 +151,7 @@ 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 +167,7 @@ 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 +189,9 @@ 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 +209,6 @@ 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/ast.nim

@@ -231,7 +231,7 @@ type
   TNodeKinds* = set[TNodeKind]
 
 type
-  TSymFlag* = enum    # 49 flags!
+  TSymFlag* = enum    # 51 flags!
     sfUsed,           # read access of sym (for warnings) or simply used
     sfExported,       # symbol is exported from module
     sfFromGeneric,    # symbol is instantiation of a generic; this is needed
@@ -283,7 +283,7 @@ type
     sfNamedParamCall, # symbol needs named parameter call syntax in target
                       # language; for interfacing with Objective C
     sfDiscardable,    # returned value may be discarded implicitly
-    sfOverriden,      # proc is overridden
+    sfOverridden,      # proc is overridden
     sfCallsite        # A flag for template symbols to tell the
                       # compiler it should use line information from
                       # the calling side of the macro, not from the
@@ -303,6 +303,8 @@ type
     sfUsedInFinallyOrExcept  # symbol is used inside an 'except' or 'finally'
     sfSingleUsedTemp  # For temporaries that we know will only be used once
     sfNoalias         # 'noalias' annotation, means C's 'restrict'
+                      # for templates and macros, means cannot be called
+                      # as a lone symbol (cannot use alias syntax)
     sfEffectsDelayed  # an 'effectsDelayed' parameter
     sfGeneratedType   # A anonymous generic type that is generated by the compiler for
                       # objects that do not have generic parameters in case one of the
@@ -310,6 +312,10 @@ type
                       #
                       # This is disallowed but can cause the typechecking to go into
                       # an infinite loop, this flag is used as a sentinel to stop it.
+    sfVirtual         # proc is a C++ virtual function
+    sfByCopy          # param is marked as pass bycopy
+    sfMember          # proc is a C++ member of a type
+    sfCodegenDecl     # type, proc, global or proc param is marked as codegenDecl
 
   TSymFlags* = set[TSymFlag]
 
@@ -335,13 +341,14 @@ const
 
   sfCompileToCpp* = sfInfixCall       # compile the module as C++ code
   sfCompileToObjc* = sfNamedParamCall # compile the module as Objective-C code
-  sfExperimental* = sfOverriden       # module uses the .experimental switch
-  sfGoto* = sfOverriden               # var is used for 'goto' code generation
+  sfExperimental* = sfOverridden       # module uses the .experimental switch
+  sfGoto* = sfOverridden               # var is used for 'goto' code generation
   sfWrittenTo* = sfBorrow             # param is assigned to
                                       # currently unimplemented
   sfBase* = sfDiscriminant
   sfCustomPragma* = sfRegister        # symbol is custom pragma template
   sfTemplateRedefinition* = sfExportc # symbol is a redefinition of an earlier template
+  sfCppMember* = { sfVirtual, sfMember, sfConstructor } # proc is a C++ member, meaning it will be attached to the type definition
 
 const
   # getting ready for the future expr/stmt merge
@@ -513,7 +520,7 @@ type
     nfSkipFieldChecking # node skips field visable checking
 
   TNodeFlags* = set[TNodeFlag]
-  TTypeFlag* = enum   # keep below 32 for efficiency reasons (now: 46)
+  TTypeFlag* = enum   # keep below 32 for efficiency reasons (now: 47)
     tfVarargs,        # procedure has C styled varargs
                       # tyArray type represeting a varargs list
     tfNoSideEffect,   # procedure type does not allow side effects
@@ -583,6 +590,8 @@ type
     tfIsConstructor
     tfEffectSystemWorkaround
     tfIsOutParam
+    tfSendable
+    tfImplicitStatic
 
   TTypeFlags* = set[TTypeFlag]
 
@@ -618,13 +627,12 @@ type
                           # file (it is loaded on demand, which may
                           # mean: never)
     skPackage,            # symbol is a package (used for canonicalization)
-    skAlias               # an alias (needs to be resolved immediately)
   TSymKinds* = set[TSymKind]
 
 const
   routineKinds* = {skProc, skFunc, skMethod, skIterator,
                    skConverter, skMacro, skTemplate}
-  ExportableSymKinds* = {skVar, skLet, skConst, skType, skEnumField, skStub, skAlias} + routineKinds
+  ExportableSymKinds* = {skVar, skLet, skConst, skType, skEnumField, skStub} + routineKinds
 
   tfUnion* = tfNoSideEffect
   tfGcSafe* = tfThread
@@ -685,7 +693,7 @@ type
     mIsPartOf, mAstToStr, mParallel,
     mSwap, mIsNil, mArrToSeq, mOpenArrayToSeq,
     mNewString, mNewStringOfCap, mParseBiggestFloat,
-    mMove, mWasMoved, mDestroy, mTrace,
+    mMove, mEnsureMove, mWasMoved, mDup, mDestroy, mTrace,
     mDefault, mUnown, mFinished, mIsolate, mAccessEnv, mAccessTypeField, mReset,
     mArray, mOpenArray, mRange, mSet, mSeq, mVarargs,
     mRef, mPtr, mVar, mDistinct, mVoid, mTuple,
@@ -818,9 +826,6 @@ type
     locOther                  # location is something other
   TLocFlag* = enum
     lfIndirect,               # backend introduced a pointer
-    lfFullExternalName, # only used when 'conf.cmd == cmdNimfix': Indicates
-      # that the symbol has been imported via 'importc: "fullname"' and
-      # no format string.
     lfNoDeepCopy,             # no need for a deep copy
     lfNoDecl,                 # do not declare it in C
     lfDynamicLib,             # link symbol to dynamic library
@@ -855,7 +860,7 @@ type
                               # keep in sync with PackedLib
     kind*: TLibKind
     generated*: bool          # needed for the backends:
-    isOverriden*: bool
+    isOverridden*: bool
     name*: Rope
     path*: PNode              # can be a string literal!
 
@@ -917,7 +922,9 @@ type
                               # for modules, an unique index corresponding
                               # to the module's fileIdx
                               # for variables a slot index for the evaluator
-    offset*: int              # offset of record field
+    offset*: int32            # offset of record field
+    disamb*: int32            # disambiguation number; the basic idea is that
+                              # `<procname>__<module>_<disamb>`
     loc*: TLoc
     annex*: PLib              # additional fields (seldom used, so we use a
                               # reference to another object to save space)
@@ -925,10 +932,11 @@ type
       cname*: string          # resolved C declaration name in importc decl, e.g.:
                               # proc fun() {.importc: "$1aux".} => cname = funaux
     constraint*: PNode        # additional constraints like 'lit|result'; also
-                              # misused for the codegenDecl pragma in the hope
+                              # misused for the codegenDecl and virtual pragmas in the hope
                               # it won't cause problems
                               # for skModule the string literal to output for
                               # deprecated modules.
+    instantiatedFrom*: PSym   # for instances, the generic symbol where it came from.
     when defined(nimsuggest):
       allUsages*: seq[TLineInfo]
 
@@ -938,6 +946,7 @@ type
     attachedWasMoved,
     attachedDestructor,
     attachedAsgn,
+    attachedDup,
     attachedSink,
     attachedTrace,
     attachedDeepCopy
@@ -950,7 +959,7 @@ type
     kind*: TTypeKind          # kind of type
     callConv*: TCallingConvention # for procs
     flags*: TTypeFlags        # flags of the type
-    sons*: TTypeSeq           # base types, etc.
+    sons: TTypeSeq           # base types, etc.
     n*: PNode                 # node for types:
                               # for range types a nkRange node
                               # for record types a nkRecord node
@@ -1031,6 +1040,8 @@ proc comment*(n: PNode): string =
   if nfHasComment in n.flags and not gconfig.useIc:
     # IC doesn't track comments, see `packed_ast`, so this could fail
     result = gconfig.comments[n.nodeId]
+  else:
+    result = ""
 
 proc `comment=`*(n: PNode, a: string) =
   let id = n.nodeId
@@ -1121,11 +1132,10 @@ const
 
 proc getPIdent*(a: PNode): PIdent {.inline.} =
   ## Returns underlying `PIdent` for `{nkSym, nkIdent}`, or `nil`.
-  # xxx consider whether also returning the 1st ident for {nkOpenSymChoice, nkClosedSymChoice}
-  # which may simplify code.
   case a.kind
   of nkSym: a.sym.name
   of nkIdent: a.ident
+  of nkOpenSymChoice, nkClosedSymChoice: a.sons[0].sym.name
   else: nil
 
 const
@@ -1141,13 +1151,17 @@ type
     symId*: int32
     typeId*: int32
     sealed*: bool
+    disambTable*: CountTable[PIdent]
 
 const
   PackageModuleId* = -3'i32
 
 proc idGeneratorFromModule*(m: PSym): IdGenerator =
   assert m.kind == skModule
-  result = IdGenerator(module: m.itemId.module, symId: m.itemId.item, typeId: 0)
+  result = IdGenerator(module: m.itemId.module, symId: m.itemId.item, typeId: 0, disambTable: initCountTable[PIdent]())
+
+proc idGeneratorForPackage*(nextIdWillBe: int32): IdGenerator =
+  result = IdGenerator(module: PackageModuleId, symId: nextIdWillBe - 1'i32, typeId: 0, disambTable: initCountTable[PIdent]())
 
 proc nextSymId*(x: IdGenerator): ItemId {.inline.} =
   assert(not x.sealed)
@@ -1214,6 +1228,7 @@ proc getDeclPragma*(n: PNode): PNode =
   case n.kind
   of routineDefs:
     if n[pragmasPos].kind != nkEmpty: result = n[pragmasPos]
+    else: result = nil
   of nkTypeDef:
     #[
     type F3*{.deprecated: "x3".} = int
@@ -1233,6 +1248,8 @@ proc getDeclPragma*(n: PNode): PNode =
     ]#
     if n[0].kind == nkPragmaExpr:
       result = n[0][1]
+    else:
+      result = nil
   else:
     # support as needed for `nkIdentDefs` etc.
     result = nil
@@ -1248,6 +1265,12 @@ proc extractPragma*(s: PSym): PNode =
       if s.ast[0].kind == nkPragmaExpr and s.ast[0].len > 1:
         # s.ast = nkTypedef / nkPragmaExpr / [nkSym, nkPragma]
         result = s.ast[0][1]
+      else:
+        result = nil
+    else:
+      result = nil
+  else:
+    result = nil
   assert result == nil or result.kind == nkPragma
 
 proc skipPragmaExpr*(n: PNode): PNode =
@@ -1339,11 +1362,15 @@ when false:
       echo k
       echo v
 
-proc newSym*(symKind: TSymKind, name: PIdent, id: ItemId, owner: PSym,
+proc newSym*(symKind: TSymKind, name: PIdent, idgen: IdGenerator; owner: PSym,
              info: TLineInfo; options: TOptions = {}): PSym =
   # generates a symbol and initializes the hash field too
+  assert not name.isNil
+  let id = nextSymId idgen
   result = PSym(name: name, kind: symKind, flags: {}, info: info, itemId: id,
-                options: options, owner: owner, offset: defaultOffset)
+                options: options, owner: owner, offset: defaultOffset,
+                disamb: getOrDefault(idgen.disambTable, name).int32)
+  idgen.disambTable.inc name
   when false:
     if id.module == 48 and id.item == 39:
       writeStackTrace()
@@ -1473,7 +1500,7 @@ proc newIntTypeNode*(intVal: BiggestInt, typ: PType): PNode =
     result = newNode(nkIntLit)
   of tyStatic: # that's a pre-existing bug, will fix in another PR
     result = newNode(nkIntLit)
-  else: doAssert false, $kind
+  else: raiseAssert $kind
   result.intVal = intVal
   result.typ = typ
 
@@ -1503,7 +1530,7 @@ proc newProcNode*(kind: TNodeKind, info: TLineInfo, body: PNode,
 
 const
   AttachedOpToStr*: array[TTypeAttachedOp, string] = [
-    "=wasMoved", "=destroy", "=copy", "=sink", "=trace", "=deepcopy"]
+    "=wasMoved", "=destroy", "=copy", "=dup", "=sink", "=trace", "=deepcopy"]
 
 proc `$`*(s: PSym): string =
   if s != nil:
@@ -1511,15 +1538,31 @@ proc `$`*(s: PSym): string =
   else:
     result = "<nil>"
 
-proc newType*(kind: TTypeKind, id: ItemId; owner: PSym): PType =
+iterator items*(t: PType): PType =
+  for i in 0..<t.sons.len: yield t.sons[i]
+
+iterator pairs*(n: PType): tuple[i: int, n: PType] =
+  for i in 0..<n.sons.len: yield (i, n.sons[i])
+
+proc newType*(kind: TTypeKind, id: ItemId; owner: PSym, sons: seq[PType] = @[]): PType =
   result = PType(kind: kind, owner: owner, size: defaultSize,
                  align: defaultAlignment, itemId: id,
-                 uniqueId: id)
+                 uniqueId: id, sons: sons)
   when false:
     if result.itemId.module == 55 and result.itemId.item == 2:
       echo "KNID ", kind
       writeStackTrace()
 
+template newType*(kind: TTypeKind, id: ItemId; owner: PSym, parent: PType): PType =
+  newType(kind, id, owner, parent.sons)
+
+proc newType*(prev: PType, sons: seq[PType]): PType =
+  result = prev
+  result.sons = sons
+
+proc addSon*(father, son: PType) =
+  # todo fixme: in IC, `son` might be nil
+  father.sons.add(son)
 
 proc mergeLoc(a: var TLoc, b: TLoc) =
   if a.k == low(typeof(a.k)): a.k = b.k
@@ -1557,8 +1600,8 @@ proc copyType*(t: PType, id: ItemId, owner: PSym): PType =
 proc exactReplica*(t: PType): PType =
   result = copyType(t, t.itemId, t.owner)
 
-proc copySym*(s: PSym; id: ItemId): PSym =
-  result = newSym(s.kind, s.name, id, s.owner, s.info, s.options)
+proc copySym*(s: PSym; idgen: IdGenerator): PSym =
+  result = newSym(s.kind, s.name, idgen, s.owner, s.info, s.options)
   #result.ast = nil            # BUGFIX; was: s.ast which made problems
   result.typ = s.typ
   result.flags = s.flags
@@ -1573,9 +1616,9 @@ proc copySym*(s: PSym; id: ItemId): PSym =
     result.bitsize = s.bitsize
     result.alignment = s.alignment
 
-proc createModuleAlias*(s: PSym, id: ItemId, newIdent: PIdent, info: TLineInfo;
+proc createModuleAlias*(s: PSym, idgen: IdGenerator, newIdent: PIdent, info: TLineInfo;
                         options: TOptions): PSym =
-  result = newSym(s.kind, newIdent, id, s.owner, info, options)
+  result = newSym(s.kind, newIdent, idgen, s.owner, info, options)
   # keep ID!
   result.ast = s.ast
   #result.id = s.id # XXX figure out what to do with the ID.
@@ -1585,19 +1628,13 @@ proc createModuleAlias*(s: PSym, id: ItemId, newIdent: PIdent, info: TLineInfo;
   result.loc = s.loc
   result.annex = s.annex
 
-proc initStrTable*(x: var TStrTable) =
-  x.counter = 0
-  newSeq(x.data, StartSize)
+proc initStrTable*(): TStrTable =
+  result = TStrTable(counter: 0)
+  newSeq(result.data, StartSize)
 
-proc newStrTable*: TStrTable =
-  initStrTable(result)
-
-proc initIdTable*(x: var TIdTable) =
-  x.counter = 0
-  newSeq(x.data, StartSize)
-
-proc newIdTable*: TIdTable =
-  initIdTable(result)
+proc initIdTable*(): TIdTable =
+  result = TIdTable(counter: 0)
+  newSeq(result.data, StartSize)
 
 proc resetIdTable*(x: var TIdTable) =
   x.counter = 0
@@ -1605,17 +1642,17 @@ proc resetIdTable*(x: var TIdTable) =
   setLen(x.data, 0)
   setLen(x.data, StartSize)
 
-proc initObjectSet*(x: var TObjectSet) =
-  x.counter = 0
-  newSeq(x.data, StartSize)
+proc initObjectSet*(): TObjectSet =
+  result = TObjectSet(counter: 0)
+  newSeq(result.data, StartSize)
 
-proc initIdNodeTable*(x: var TIdNodeTable) =
-  x.counter = 0
-  newSeq(x.data, StartSize)
+proc initIdNodeTable*(): TIdNodeTable =
+  result = TIdNodeTable(counter: 0)
+  newSeq(result.data, StartSize)
 
-proc initNodeTable*(x: var TNodeTable) =
-  x.counter = 0
-  newSeq(x.data, StartSize)
+proc initNodeTable*(): TNodeTable =
+  result = TNodeTable(counter: 0)
+  newSeq(result.data, StartSize)
 
 proc skipTypes*(t: PType, kinds: TTypeKinds; maxIters: int): PType =
   result = t
@@ -1799,6 +1836,7 @@ proc hasNilSon*(n: PNode): bool =
   result = false
 
 proc containsNode*(n: PNode, kinds: TNodeKinds): bool =
+  result = false
   if n == nil: return
   case n.kind
   of nkEmpty..nkNilLit: result = n.kind in kinds
@@ -1899,7 +1937,7 @@ proc skipGenericOwner*(s: PSym): PSym =
   ## Generic instantiations are owned by their originating generic
   ## symbol. This proc skips such owners and goes straight to the owner
   ## of the generic itself (the module or the enclosing proc).
-  result = if s.kind in skProcKinds and sfFromGeneric in s.flags:
+  result = if s.kind in skProcKinds and sfFromGeneric in s.flags and s.owner.kind != skModule:
              s.owner.owner
            else:
              s.owner
@@ -1915,20 +1953,6 @@ proc isCompileTimeProc*(s: PSym): bool {.inline.} =
   result = s.kind == skMacro or
            s.kind in {skProc, skFunc} and sfCompileTime in s.flags
 
-proc isRunnableExamples*(n: PNode): bool =
-  # Templates and generics don't perform symbol lookups.
-  result = n.kind == nkSym and n.sym.magic == mRunnableExamples or
-    n.kind == nkIdent and n.ident.s == "runnableExamples"
-
-proc requiredParams*(s: PSym): int =
-  # Returns the number of required params (without default values)
-  # XXX: Perhaps we can store this in the `offset` field of the
-  # symbol instead?
-  for i in 1..<s.typ.len:
-    if s.typ.n[i].sym.ast != nil:
-      return i - 1
-  return s.typ.len - 1
-
 proc hasPattern*(s: PSym): bool {.inline.} =
   result = isRoutine(s) and s.ast[patternPos].kind != nkEmpty
 
@@ -2002,7 +2026,7 @@ proc toObjectFromRefPtrGeneric*(typ: PType): PType =
     of tyRef, tyPtr, tyGenericInst, tyGenericInvocation, tyAlias: result = result[0]
       # automatic dereferencing is deep, refs #18298.
     else: break
-  assert result.sym != nil
+  # result does not have to be object type
 
 proc isImportedException*(t: PType; conf: ConfigRef): bool =
   assert t != nil
@@ -2014,6 +2038,8 @@ proc isImportedException*(t: PType; conf: ConfigRef): bool =
 
   if base.sym != nil and {sfCompileToCpp, sfImportc} * base.sym.flags != {}:
     result = true
+  else:
+    result = false
 
 proc isInfixAs*(n: PNode): bool =
   return n.kind == nkInfix and n[0].kind == nkIdent and n[0].ident.s == "as"
@@ -2024,10 +2050,12 @@ proc skipColon*(n: PNode): PNode =
     result = n[1]
 
 proc findUnresolvedStatic*(n: PNode): PNode =
-  # n.typ == nil: see issue #14802
   if n.kind == nkSym and n.typ != nil and n.typ.kind == tyStatic and n.typ.n == nil:
     return n
-
+  if n.typ != nil and n.typ.kind == tyTypeDesc:
+    let t = skipTypes(n.typ, {tyTypeDesc})
+    if t.kind == tyGenericParam and t.len == 0:
+      return n
   for son in n:
     let n = son.findUnresolvedStatic
     if n != nil: return n
@@ -2065,6 +2093,12 @@ proc isClosureIterator*(typ: PType): bool {.inline.} =
 proc isClosure*(typ: PType): bool {.inline.} =
   typ.kind == tyProc and typ.callConv == ccClosure
 
+proc isNimcall*(s: PSym): bool {.inline.} =
+  s.typ.callConv == ccNimCall
+
+proc isExplicitCallConv*(s: PSym): bool {.inline.} =
+  tfExplicitCallConv in s.typ.flags
+
 proc isSinkParam*(s: PSym): bool {.inline.} =
   s.kind == skParam and (s.typ.kind == tySink or tfHasOwned in s.typ.flags)
 
@@ -2139,3 +2173,7 @@ const
     nkFuncDef, nkConstSection, nkConstDef, nkIncludeStmt, nkImportStmt,
     nkExportStmt, nkPragma, nkCommentStmt, nkBreakState,
     nkTypeOfExpr, nkMixinStmt, nkBindStmt}
+
+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

compiler/astalgo.nim

@@ -109,7 +109,7 @@ 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 +197,7 @@ 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 +227,11 @@ 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
@@ -327,8 +329,10 @@ proc typeToYamlAux(conf: ConfigRef; n: PType, marker: var IntSet, indent: int,
                    maxRecDepth: int): Rope =
   var sonsRope: Rope
   if n == nil:
+    result = ""
     sonsRope = rope("null")
   elif containsOrIncl(marker, n.id):
+    result = ""
     sonsRope = "\"$1 @$2\"" % [rope($n.kind), rope(
         strutils.toHex(cast[int](n), sizeof(n) * 2))]
   else:
@@ -1063,6 +1067,7 @@ proc isAddrNode*(n: PNode): bool =
     else: false
 
 proc listSymbolNames*(symbols: openArray[PSym]): string =
+  result = ""
   for sym in symbols:
     if result.len > 0:
       result.add ", "

compiler/bitsets.nim

@@ -87,5 +87,6 @@ const populationCount: array[uint8, uint8] = block:
     arr
 
 proc bitSetCard*(x: TBitSet): BiggestInt =
+  result = 0
   for it in x:
     result.inc int(populationCount[it])

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]
@@ -87,7 +89,7 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
       # 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[0], needsInit=true)
         elif d.k notin {locTemp} and not hasNoInit(ri):
           # reset before pass as 'result' var:
           discard "resetLoc(p, d)"
@@ -95,8 +97,7 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
         pl.add(");\n")
         line(p, cpsStmts, pl)
       else:
-        var tmp: TLoc
-        getTemp(p, typ[0], tmp, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ[0], needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         pl.add(");\n")
         line(p, cpsStmts, pl)
@@ -114,28 +115,24 @@ 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[0], 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[0])
+            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)
+        if d.k == locNone: d = getTemp(p, typ[0])
         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)
       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[0], 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)
@@ -157,10 +154,9 @@ proc reifiedOpenArray(n: PNode): bool {.inline.} =
     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)
@@ -205,6 +201,7 @@ 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) =
@@ -224,8 +221,7 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
     let (x, y) = genOpenArraySlice(p, q, formalType, n.typ[0])
     result.add x & ", " & y
   else:
-    var a: TLoc
-    initLocExpr(p, if n.kind == nkHiddenStdConv: n[1] else: n, a)
+    var a: TLoc = initLocExpr(p, if n.kind == nkHiddenStdConv: n[1] else: n)
     case skipTypes(a.t, abstractVar+{tyStatic}).kind
     of tyOpenArray, tyVarargs:
       if reifiedOpenArray(n):
@@ -269,20 +265,19 @@ 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: TLoc = 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 +287,16 @@ 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[0]) 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 +307,7 @@ 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)
     addRdLoc(withTmpIfNeeded(p, a, needsTmp), result)
   #assert result != nil
 
@@ -320,12 +316,13 @@ 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
@@ -381,13 +378,13 @@ 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]:
@@ -419,9 +416,8 @@ 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: TLoc = initLocExpr(p, ri[0])
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInstOwned)
   assert(typ.kind == tyProc)
@@ -443,8 +439,7 @@ 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: TLoc = initLocExpr(p, ri[0])
 
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInstOwned)
@@ -469,7 +464,7 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
       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[0], needsInit=true)
         elif d.k notin {locTemp} and not hasNoInit(ri):
           # reset before pass as 'result' var:
           discard "resetLoc(p, d)"
@@ -477,17 +472,15 @@ 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[0], needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         genCallPattern()
         if canRaise: raiseExit(p)
         genAssignment(p, d, tmp, {}) # no need for deep copying
     elif isHarmlessStore(p, canRaise, d):
-      if d.k == locNone: getTemp(p, typ[0], d)
+      if d.k == locNone: d = getTemp(p, typ[0])
       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 +488,9 @@ 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[0])
       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:
@@ -667,7 +658,7 @@ 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")
@@ -681,8 +672,7 @@ 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: TLoc = initLocExpr(p, ri[0])
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
   assert(typ.kind == tyProc)
@@ -704,10 +694,9 @@ 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[0])
         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:
@@ -727,8 +716,7 @@ proc genInfixCall(p: BProc, le, ri: PNode, d: var TLoc) =
 
 proc genNamedParamCall(p: BProc, ri: PNode, d: var TLoc) =
   # generates a crappy ObjC call
-  var op: TLoc
-  initLocExpr(p, ri[0], op)
+  var op: TLoc = initLocExpr(p, ri[0])
   var pl = "["
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
@@ -770,24 +758,22 @@ proc genNamedParamCall(p: BProc, ri: PNode, d: var TLoc) =
       # 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[0], needsInit=true)
         pl.add("Result: ")
         pl.add(addrLoc(p.config, d))
         pl.add("];\n")
         line(p, cpsStmts, pl)
       else:
-        var tmp: TLoc
-        getTemp(p, typ[0], tmp, needsInit=true)
+        var tmp: TLoc = getTemp(p, typ[0], needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         pl.add("];\n")
         line(p, cpsStmts, pl)
         genAssignment(p, d, tmp, {}) # no need for deep copying
     else:
       pl.add("]")
-      if d.k == locNone: getTemp(p, typ[0], d)
+      if d.k == locNone: d = getTemp(p, typ[0])
       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

@@ -57,8 +57,7 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
     specializeResetT(p, accessor, lastSon(typ))
   of tyArray:
     let arraySize = lengthOrd(p.config, typ[0])
-    var i: TLoc
-    getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt), i)
+    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])
@@ -95,12 +94,12 @@ 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,
+      raiseAssert "unexpected set type kind"
+  of tyNone, tyEmpty, tyNil, tyUntyped, tyTyped, tyGenericInvocation,
       tyGenericParam, tyOrdinal, tyRange, 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 +289,28 @@ 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 genCppVarForCtor(p: BProc, v: PSym; vn, value: PNode; decl: var Rope) =
+  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:
+    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 +322,11 @@ 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):
+      callGlobalVarCppCtor(targetProc, v, vn, value)
+    else:
+      assignGlobalVar(targetProc, vn, valueAsRope)
+
     # XXX: be careful here.
     # Global variables should not be zeromem-ed within loops
     # (see bug #20).
@@ -313,13 +335,12 @@ 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 +348,21 @@ 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:
+        genCppVarForCtor(p, v, vn, value, decl)
+        line(p, cpsStmts, decl)
       else:
-        initLocExprSingleUse(p, value, tmp)
-        lineF(p, cpsStmts, "$# = $#;$n", [decl, tmp.rdLoc])
+        tmp = initLocExprSingleUse(p, value)
+        lineF(p, cpsStmts, "$# = $#;\n", [decl, tmp.rdLoc])
       return
     assignLocalVar(p, vn)
     initLocalVar(p, v, imm)
@@ -378,7 +389,8 @@ 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 +407,7 @@ 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 +442,7 @@ 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 +450,7 @@ 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 +518,7 @@ 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 +552,7 @@ 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 +590,7 @@ 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 +618,11 @@ 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 +637,7 @@ 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 +657,13 @@ 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])
 
     # $n at the beginning because of #9710
     if call.len == 4: # procName(a, b, annotation)
@@ -672,8 +680,7 @@ proc genParForStmt(p: BProc, t: PNode) =
                     rangeA.rdLoc, rangeB.rdLoc,
                     call[3].getStr.rope])
     else: # `||`(a, b, step, annotation)
-      var step: TLoc
-      initLocExpr(p, call[3], step)
+      var step: TLoc = initLocExpr(p, call[3])
       lineF(p, cpsStmts, "$n#pragma omp $5$n" &
                     "for ($1 = $2; $1 <= $3; $1 += $4)",
                     [forLoopVar.loc.rdLoc,
@@ -743,8 +750,7 @@ 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 +772,7 @@ 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 +780,12 @@ 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 +827,7 @@ 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 +837,8 @@ 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 +861,7 @@ 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 +897,7 @@ 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 +905,7 @@ 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 +941,7 @@ 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",
@@ -970,7 +971,7 @@ proc genOrdinalCase(p: BProc, n: PNode, d: var TLoc) =
 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 +997,7 @@ 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 +1022,13 @@ 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]))
+  lineCg(p, cpsStmts, "std::exception_ptr T$1_;$n", [etmp])
 
   let fin = if t[^1].kind == nkFinally: t[^1] else: nil
   p.nestedTryStmts.add((fin, false, 0.Natural))
@@ -1061,7 +1062,6 @@ 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 +1124,7 @@ proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =
 
       if t[i].len == 1:
         # general except section:
-        startBlock(p, "catch (...) {", [])
+        startBlock(p, "catch (...) {$n", [])
         genExceptBranchBody(t[i][0])
         endBlock(p)
         catchAllPresent = true
@@ -1150,7 +1150,7 @@ proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =
   # general finally block:
   if t.len > 0 and t[^1].kind == nkFinally:
     if not catchAllPresent:
-      startBlock(p, "catch (...) {", [])
+      startBlock(p, "catch (...) {$n", [])
       genRestoreFrameAfterException(p)
       linefmt(p, cpsStmts, "T$1_ = std::current_exception();$n", [etmp])
       endBlock(p)
@@ -1187,7 +1187,7 @@ 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 +1265,7 @@ 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 +1300,8 @@ 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 +1372,7 @@ 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 +1381,7 @@ 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 +1446,8 @@ 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, $2)", [memberName, checkFor])
@@ -1483,8 +1485,7 @@ proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
     of nkSym:
       var sym = it.sym
       if sym.kind in {skProc, skFunc, skIterator, skMethod}:
-        var a: TLoc
-        initLocExpr(p, it, a)
+        var a: TLoc = initLocExpr(p, it)
         res.add($rdLoc(a))
       elif sym.kind == skType:
         res.add($getTypeDesc(p.module, sym.typ))
@@ -1496,8 +1497,7 @@ proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
       res.add($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:
@@ -1599,11 +1599,10 @@ 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 +1620,8 @@ 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 +1633,7 @@ 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) =
@@ -74,8 +74,7 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType) =
     genTraverseProc(c, accessor, lastSon(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)
+    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",
@@ -119,12 +118,10 @@ 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: TLoc = 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 = TLoc(r: accessor)
 
   lineF(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
       [i.r, lenExpr(c.p, a)])

compiler/ccgutils.nim

@@ -19,13 +19,16 @@ 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
@@ -121,8 +124,11 @@ proc mapSetType(conf: ConfigRef; typ: PType): TCTypeKind =
 proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
   var pt = skipTypes(s.typ, typedescInst)
   assert skResult != s.kind
-
-  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:

compiler/cgen.nim

@@ -17,6 +17,8 @@ import
   lowerings, tables, sets, ndi, lineinfos, pathutils, transf,
   injectdestructors, astmsgs, modulepaths, backendpragmas
 
+import nir/ast2ir
+
 import pipelineutils
 
 when defined(nimPreviewSlimSystem):
@@ -61,12 +63,10 @@ proc findPendingModule(m: BModule, s: PSym): BModule =
     var ms = getModule(s)
     result = m.g.modules[ms.position]
 
-proc initLoc(result: var TLoc, k: TLocKind, lode: PNode, s: TStorageLoc) =
-  result.k = k
-  result.storage = s
-  result.lode = lode
-  result.r = ""
-  result.flags = {}
+proc initLoc(k: TLocKind, lode: PNode, s: TStorageLoc, flags: TLocFlags = {}): TLoc =
+  result = TLoc(k: k, storage: s, lode: lode,
+               r: "", flags: flags
+  )
 
 proc fillLoc(a: var TLoc, k: TLocKind, lode: PNode, r: Rope, s: TStorageLoc) {.inline.} =
   # fills the loc if it is not already initialized
@@ -216,13 +216,9 @@ macro ropecg(m: BModule, frmt: static[FormatStr], args: untyped): Rope =
     elif frmt[i] == '#' and frmt[i+1] == '#':
       inc(i, 2)
       strLit.add("#")
-
-    var start = i
-    while i < frmt.len:
-      if frmt[i] != '$' and frmt[i] != '#': inc(i)
-      else: break
-    if i - 1 >= start:
-      strLit.add(substr(frmt, start, i - 1))
+    else:
+      strLit.add(frmt[i])
+      inc(i)
 
   flushStrLit()
   result.add newCall(ident"rope", resVar)
@@ -273,7 +269,16 @@ proc safeLineNm(info: TLineInfo): int =
 proc genCLineDir(r: var Rope, filename: string, line: int; conf: ConfigRef) =
   assert line >= 0
   if optLineDir in conf.options and line > 0:
-    r.addf("$N#line $2 $1$N",
+    r.addf("\n#line $2 $1\n",
+        [rope(makeSingleLineCString(filename)), rope(line)])
+
+proc genCLineDir(r: var Rope, filename: string, line: int; p: BProc; info: TLineInfo; lastFileIndex: FileIndex) =
+  assert line >= 0
+  if optLineDir in p.config.options and line > 0:
+    if lastFileIndex == info.fileIndex:
+        r.addf("\n#line $1\n", [rope(line)])
+    else:
+      r.addf("\n#line $2 $1\n",
         [rope(makeSingleLineCString(filename)), rope(line)])
 
 proc genCLineDir(r: var Rope, info: TLineInfo; conf: ConfigRef) =
@@ -286,17 +291,33 @@ proc freshLineInfo(p: BProc; info: TLineInfo): bool =
     p.lastLineInfo.line = info.line
     p.lastLineInfo.fileIndex = info.fileIndex
     result = true
+  else:
+    result = false
+
+proc genCLineDir(r: var Rope, p: BProc, info: TLineInfo; conf: ConfigRef) =
+  if optLineDir in conf.options:
+    let lastFileIndex = p.lastLineInfo.fileIndex
+    if freshLineInfo(p, info):
+      genCLineDir(r, toFullPath(conf, info), info.safeLineNm, p, info, lastFileIndex)
 
 proc genLineDir(p: BProc, t: PNode) =
+  if p == p.module.preInitProc: return
   let line = t.info.safeLineNm
 
   if optEmbedOrigSrc in p.config.globalOptions:
     p.s(cpsStmts).add("//" & sourceLine(p.config, t.info) & "\L")
-  genCLineDir(p.s(cpsStmts), t.info, p.config)
+  let lastFileIndex = p.lastLineInfo.fileIndex
+  let freshLine = freshLineInfo(p, t.info)
+  if freshLine:
+    genCLineDir(p.s(cpsStmts), toFullPath(p.config, t.info), line, p, t.info, lastFileIndex)
   if ({optLineTrace, optStackTrace} * p.options == {optLineTrace, optStackTrace}) and
       (p.prc == nil or sfPure notin p.prc.flags) and t.info.fileIndex != InvalidFileIdx:
-    if freshLineInfo(p, t.info):
-      linefmt(p, cpsStmts, "nimln_($1, $2);$n",
+      if freshLine:
+        if lastFileIndex == t.info.fileIndex:
+          linefmt(p, cpsStmts, "nimln_($1);",
+              [line])
+        else:
+          linefmt(p, cpsStmts, "nimlf_($1, $2);",
               [line, quotedFilename(p.config, t.info)])
 
 proc accessThreadLocalVar(p: BProc, s: PSym)
@@ -356,19 +377,19 @@ template mapTypeChooser(n: PNode): TSymKind =
 template mapTypeChooser(a: TLoc): TSymKind = mapTypeChooser(a.lode)
 
 proc addAddrLoc(conf: ConfigRef; a: TLoc; result: var Rope) =
-  if lfIndirect notin a.flags and mapType(conf, a.t, mapTypeChooser(a)) != ctArray:
+  if lfIndirect notin a.flags and mapType(conf, a.t, mapTypeChooser(a) == skParam) != ctArray:
     result.add "(&" & a.r & ")"
   else:
     result.add a.r
 
 proc addrLoc(conf: ConfigRef; a: TLoc): Rope =
-  if lfIndirect notin a.flags and mapType(conf, a.t, mapTypeChooser(a)) != ctArray:
+  if lfIndirect notin a.flags and mapType(conf, a.t, mapTypeChooser(a) == skParam) != ctArray:
     result = "(&" & a.r & ")"
   else:
     result = a.r
 
 proc byRefLoc(p: BProc; a: TLoc): Rope =
-  if lfIndirect notin a.flags and mapType(p.config, a.t, mapTypeChooser(a)) != ctArray and not
+  if lfIndirect notin a.flags and mapType(p.config, a.t, mapTypeChooser(a) == skParam) != ctArray and not
       p.module.compileToCpp:
     result = "(&" & a.r & ")"
   else:
@@ -414,13 +435,13 @@ proc genObjectInit(p: BProc, section: TCProcSection, t: PType, a: var TLoc,
       linefmt(p, section, "$1.m_type = $2;$n", [r, genTypeInfoV1(p.module, t, a.lode.info)])
   of frEmbedded:
     if optTinyRtti in p.config.globalOptions:
-      var tmp: TLoc
+      var tmp: TLoc = default(TLoc)
       if mode == constructRefObj:
         let objType = t.skipTypes(abstractInst+{tyRef})
         rawConstExpr(p, newNodeIT(nkType, a.lode.info, objType), tmp)
         linefmt(p, cpsStmts,
             "#nimCopyMem((void*)$1, (NIM_CONST void*)&$2, sizeof($3));$n",
-            [rdLoc(a), rdLoc(tmp), getTypeDesc(p.module, objType, mapTypeChooser(a))])
+            [rdLoc(a), rdLoc(tmp), getTypeDesc(p.module, objType, descKindFromSymKind mapTypeChooser(a))])
       else:
         rawConstExpr(p, newNodeIT(nkType, a.lode.info, t), tmp)
         genAssignment(p, a, tmp, {})
@@ -462,8 +483,7 @@ proc resetLoc(p: BProc, loc: var TLoc) =
       linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
   elif not isComplexValueType(typ):
     if containsGcRef:
-      var nilLoc: TLoc
-      initLoc(nilLoc, locTemp, loc.lode, OnStack)
+      var nilLoc: TLoc = initLoc(locTemp, loc.lode, OnStack)
       nilLoc.r = rope("NIM_NIL")
       genRefAssign(p, loc, nilLoc)
     else:
@@ -480,36 +500,40 @@ proc resetLoc(p: BProc, loc: var TLoc) =
     else:
       # array passed as argument decayed into pointer, bug #7332
       # so we use getTypeDesc here rather than rdLoc(loc)
-      linefmt(p, cpsStmts, "#nimZeroMem((void*)$1, sizeof($2));$n",
-              [addrLoc(p.config, loc),
-              getTypeDesc(p.module, loc.t, mapTypeChooser(loc))])
+      let tyDesc = getTypeDesc(p.module, loc.t, descKindFromSymKind mapTypeChooser(loc))
+      if p.module.compileToCpp and isOrHasImportedCppType(typ): 
+        if lfIndirect in loc.flags: 
+          #C++ cant be just zeroed. We need to call the ctors
+          var tmp = getTemp(p, loc.t)
+          linefmt(p, cpsStmts,"#nimCopyMem((void*)$1, (NIM_CONST void*)$2, sizeof($3));$n",
+                  [addrLoc(p.config, loc), addrLoc(p.config, tmp), tyDesc])
+      else:
+        linefmt(p, cpsStmts, "#nimZeroMem((void*)$1, sizeof($2));$n",
+                [addrLoc(p.config, loc), tyDesc])
+      
       # XXX: We can be extra clever here and call memset only
       # on the bytes following the m_type field?
       genObjectInit(p, cpsStmts, loc.t, loc, constructObj)
 
-proc isOrHasImportedCppType(typ: PType): bool =
-  searchTypeFor(typ.skipTypes({tyRef}), isImportedCppType)
-
 proc constructLoc(p: BProc, loc: var TLoc, isTemp = false) =
   let typ = loc.t
   if optSeqDestructors in p.config.globalOptions and skipTypes(typ, abstractInst + {tyStatic}).kind in {tyString, tySequence}:
     linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
   elif not isComplexValueType(typ):
     if containsGarbageCollectedRef(loc.t):
-      var nilLoc: TLoc
-      initLoc(nilLoc, locTemp, loc.lode, OnStack)
+      var nilLoc: TLoc = initLoc(locTemp, loc.lode, OnStack)
       nilLoc.r = rope("NIM_NIL")
       genRefAssign(p, loc, nilLoc)
     else:
       linefmt(p, cpsStmts, "$1 = ($2)0;$n", [rdLoc(loc),
-        getTypeDesc(p.module, typ, mapTypeChooser(loc))])
+        getTypeDesc(p.module, typ, descKindFromSymKind mapTypeChooser(loc))])
   else:
     if not isTemp or containsGarbageCollectedRef(loc.t):
       # don't use nimZeroMem for temporary values for performance if we can
       # avoid it:
       if not isOrHasImportedCppType(typ):
         linefmt(p, cpsStmts, "#nimZeroMem((void*)$1, sizeof($2));$n",
-                [addrLoc(p.config, loc), getTypeDesc(p.module, typ, mapTypeChooser(loc))])
+                [addrLoc(p.config, loc), getTypeDesc(p.module, typ, descKindFromSymKind mapTypeChooser(loc))])
     genObjectInit(p, cpsStmts, loc.t, loc, constructObj)
 
 proc initLocalVar(p: BProc, v: PSym, immediateAsgn: bool) =
@@ -524,17 +548,14 @@ proc initLocalVar(p: BProc, v: PSym, immediateAsgn: bool) =
     if not immediateAsgn:
       constructLoc(p, v.loc)
 
-proc getTemp(p: BProc, t: PType, result: var TLoc; needsInit=false) =
+proc getTemp(p: BProc, t: PType, needsInit=false): TLoc =
   inc(p.labels)
-  result.r = "T" & rope(p.labels) & "_"
+  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp, lode: lodeTyp t,
+                storage: OnStack, flags: {})
   if p.module.compileToCpp and isOrHasImportedCppType(t):
-    linefmt(p, cpsLocals, "$1 $2{};$n", [getTypeDesc(p.module, t, skVar), result.r])
+    linefmt(p, cpsLocals, "$1 $2{};$n", [getTypeDesc(p.module, t, dkVar), result.r])
   else:
-    linefmt(p, cpsLocals, "$1 $2;$n", [getTypeDesc(p.module, t, skVar), result.r])
-  result.k = locTemp
-  result.lode = lodeTyp t
-  result.storage = OnStack
-  result.flags = {}
+    linefmt(p, cpsLocals, "$1 $2;$n", [getTypeDesc(p.module, t, dkVar), result.r])
   constructLoc(p, result, not needsInit)
   when false:
     # XXX Introduce a compiler switch in order to detect these easily.
@@ -545,25 +566,21 @@ proc getTemp(p: BProc, t: PType, result: var TLoc; needsInit=false) =
         echo "ENORMOUS TEMPORARY! ", p.config $ p.lastLineInfo
       writeStackTrace()
 
-proc getTempCpp(p: BProc, t: PType, result: var TLoc; value: Rope) =
+proc getTempCpp(p: BProc, t: PType, value: Rope): TLoc =
   inc(p.labels)
-  result.r = "T" & rope(p.labels) & "_"
-  linefmt(p, cpsStmts, "$1 $2 = $3;$n", [getTypeDesc(p.module, t, skVar), result.r, value])
-  result.k = locTemp
-  result.lode = lodeTyp t
-  result.storage = OnStack
-  result.flags = {}
+  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp, lode: lodeTyp t,
+                storage: OnStack, flags: {})
+  linefmt(p, cpsStmts, "$1 $2 = $3;$n", [getTypeDesc(p.module, t, dkVar), result.r, value])
 
-proc getIntTemp(p: BProc, result: var TLoc) =
+proc getIntTemp(p: BProc): TLoc =
   inc(p.labels)
-  result.r = "T" & rope(p.labels) & "_"
+  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp,
+                storage: OnStack, lode: lodeTyp getSysType(p.module.g.graph, unknownLineInfo, tyInt),
+                flags: {})
   linefmt(p, cpsLocals, "NI $1;$n", [result.r])
-  result.k = locTemp
-  result.storage = OnStack
-  result.lode = lodeTyp getSysType(p.module.g.graph, unknownLineInfo, tyInt)
-  result.flags = {}
 
 proc localVarDecl(p: BProc; n: PNode): Rope =
+  result = ""
   let s = n.sym
   if s.loc.k == locNone:
     fillLocalName(p, s)
@@ -572,10 +589,10 @@ proc localVarDecl(p: BProc; n: PNode): Rope =
   if s.kind in {skLet, skVar, skField, skForVar} and s.alignment > 0:
     result.addf("NIM_ALIGN($1) ", [rope(s.alignment)])
 
-  genCLineDir(result, n.info, p.config)
+  genCLineDir(result, p, n.info, p.config)
 
-  result.add getTypeDesc(p.module, s.typ, skVar)
-  if s.constraint.isNil:
+  result.add getTypeDesc(p.module, s.typ, dkVar)
+  if sfCodegenDecl notin s.flags:
     if sfRegister in s.flags: result.add(" register")
     #elif skipTypes(s.typ, abstractInst).kind in GcTypeKinds:
     #  decl.add(" GC_GUARD")
@@ -590,7 +607,7 @@ proc assignLocalVar(p: BProc, n: PNode) =
   #assert(s.loc.k == locNone) # not yet assigned
   # this need not be fulfilled for inline procs; they are regenerated
   # for each module that uses them!
-  let nl = if optLineDir in p.config.options: "" else: "\L"
+  let nl = if optLineDir in p.config.options: "" else: "\n"
   let decl = localVarDecl(p, n) & (if p.module.compileToCpp and isOrHasImportedCppType(n.typ): "{};" else: ";") & nl
   line(p, cpsLocals, decl)
 
@@ -604,6 +621,40 @@ proc treatGlobalDifferentlyForHCR(m: BModule, s: PSym): bool =
       # and s.owner.kind == skModule # owner isn't always a module (global pragma on local var)
       # and s.loc.k == locGlobalVar  # loc isn't always initialized when this proc is used
 
+proc genGlobalVarDecl(p: BProc, n: PNode; td, value: Rope; decl: var Rope) =
+  let s = n.sym
+  if sfCodegenDecl notin s.flags:
+    if s.kind in {skLet, skVar, skField, skForVar} and s.alignment > 0:
+      decl.addf "NIM_ALIGN($1) ", [rope(s.alignment)]
+    if p.hcrOn: decl.add("static ")
+    elif sfImportc in s.flags: decl.add("extern ")
+    elif lfExportLib in s.loc.flags: decl.add("N_LIB_EXPORT_VAR ")
+    else: decl.add("N_LIB_PRIVATE ")
+    if s.kind == skLet and value != "": decl.add("NIM_CONST ")
+    decl.add(td)
+    if p.hcrOn: decl.add("*")
+    if sfRegister in s.flags: decl.add(" register")
+    if sfVolatile in s.flags: decl.add(" volatile")
+    if sfNoalias in s.flags: decl.add(" NIM_NOALIAS")
+  else:
+    if value != "":
+      decl = runtimeFormat(s.cgDeclFrmt & " = $#;$n", [td, s.loc.r, value])
+    else:
+      decl = runtimeFormat(s.cgDeclFrmt & ";$n", [td, s.loc.r])
+
+proc genCppVarForCtor(p: BProc, v: PSym; vn, value: PNode; decl: var Rope)
+
+proc callGlobalVarCppCtor(p: BProc; v: PSym; vn, value: PNode) =
+  let s = vn.sym
+  fillBackendName(p.module, s)
+  fillLoc(s.loc, locGlobalVar, vn, OnHeap)
+  var decl: Rope = ""
+  let td = getTypeDesc(p.module, vn.sym.typ, dkVar)
+  genGlobalVarDecl(p, vn, td, "", decl)
+  decl.add " " & $s.loc.r
+  genCppVarForCtor(p, v, vn, value, decl)
+  p.module.s[cfsVars].add decl
+
 proc assignGlobalVar(p: BProc, n: PNode; value: Rope) =
   let s = n.sym
   if s.loc.k == locNone:
@@ -629,29 +680,30 @@ proc assignGlobalVar(p: BProc, n: PNode; value: Rope) =
         internalError(p.config, n.info, ".threadvar variables cannot have a value")
     else:
       var decl: Rope = ""
-      var td = getTypeDesc(p.module, s.loc.t, skVar)
+      let td = getTypeDesc(p.module, s.loc.t, dkVar)
+      genGlobalVarDecl(p, n, td, value, decl)
       if s.constraint.isNil:
-        if s.kind in {skLet, skVar, skField, skForVar} and s.alignment > 0:
-          decl.addf "NIM_ALIGN($1) ", [rope(s.alignment)]
-        if p.hcrOn: decl.add("static ")
-        elif sfImportc in s.flags: decl.add("extern ")
-        elif lfExportLib in s.loc.flags: decl.add("N_LIB_EXPORT_VAR ")
-        else: decl.add("N_LIB_PRIVATE ")
-        if s.kind == skLet and value != "": decl.add("NIM_CONST ")
-        decl.add(td)
-        if p.hcrOn: decl.add("*")
-        if sfRegister in s.flags: decl.add(" register")
-        if sfVolatile in s.flags: decl.add(" volatile")
-        if sfNoalias in s.flags: decl.add(" NIM_NOALIAS")
         if value != "":
-          decl.addf(" $1 = $2;$n", [s.loc.r, value])
+          if p.module.compileToCpp and value.startsWith "{{}":
+            # TODO: taking this branch, re"\{\{\}(,\s\{\})*\}" might be emitted, resulting in
+            # either warnings (GCC 12.2+) or errors (Clang 15, MSVC 19.3+) of C++11+ compilers **when
+            # explicit constructors are around** due to overload resolution rules in place [^0][^1][^2]
+            # *Workaround* here: have C++'s static initialization mechanism do the default init work,
+            # for us lacking a deeper knowledge of an imported object's constructors' ex-/implicitness
+            # (so far) *and yet* trying to achieve default initialization.
+            # Still, generating {}s in genConstObjConstr() just to omit them here is faaaar from ideal;
+            # need to figure out a better way, possibly by keeping around more data about the
+            # imported objects' contructors?
+            #
+            # [^0]: https://en.cppreference.com/w/cpp/language/aggregate_initialization
+            # [^1]: https://cplusplus.github.io/CWG/issues/1518.html
+            # [^2]: https://eel.is/c++draft/over.match.ctor
+            decl.addf(" $1;$n", [s.loc.r])
+          else:
+            decl.addf(" $1 = $2;$n", [s.loc.r, value])
         else:
           decl.addf(" $1;$n", [s.loc.r])
-      else:
-        if value != "":
-          decl = runtimeFormat(s.cgDeclFrmt & " = $#;$n", [td, s.loc.r, value])
-        else:
-          decl = runtimeFormat(s.cgDeclFrmt & ";$n", [td, s.loc.r])
+
       p.module.s[cfsVars].add(decl)
   if p.withinLoop > 0 and value == "":
     # fixes tests/run/tzeroarray:
@@ -672,7 +724,7 @@ proc getLabel(p: BProc): TLabel =
   result = "LA" & rope(p.labels) & "_"
 
 proc fixLabel(p: BProc, labl: TLabel) =
-  lineF(p, cpsStmts, "$1: ;$n", [labl])
+  p.s(cpsStmts).add("$1: ;$n" % [labl])
 
 proc genVarPrototype(m: BModule, n: PNode)
 proc requestConstImpl(p: BProc, sym: PSym)
@@ -685,12 +737,12 @@ proc genLiteral(p: BProc, n: PNode; result: var Rope)
 proc genOtherArg(p: BProc; ri: PNode; i: int; typ: PType; result: var Rope; argsCounter: var int)
 proc raiseExit(p: BProc)
 
-proc initLocExpr(p: BProc, e: PNode, result: var TLoc) =
-  initLoc(result, locNone, e, OnUnknown)
+proc initLocExpr(p: BProc, e: PNode, flags: TLocFlags = {}): TLoc =
+  result = initLoc(locNone, e, OnUnknown, flags)
   expr(p, e, result)
 
-proc initLocExprSingleUse(p: BProc, e: PNode, result: var TLoc) =
-  initLoc(result, locNone, e, OnUnknown)
+proc initLocExprSingleUse(p: BProc, e: PNode): TLoc =
+  result = initLoc(locNone, e, OnUnknown)
   if e.kind in nkCallKinds and (e[0].kind != nkSym or e[0].sym.magic == mNone):
     # We cannot check for tfNoSideEffect here because of mutable parameters.
     discard "bug #8202; enforce evaluation order for nested calls for C++ too"
@@ -714,8 +766,12 @@ $1define nimfr_(proc, file) \
     struct {TFrame* prev;NCSTRING procname;NI line;NCSTRING filename;NI len;VarSlot s[slots];} FR_; \
     FR_.procname = proc; FR_.filename = file; FR_.line = 0; FR_.len = length; #nimFrame((TFrame*)&FR_);
 
-  $1define nimln_(n, file) \
+  $1define nimln_(n) \
+    FR_.line = n;
+
+  $1define nimlf_(n, file) \
     FR_.line = n; FR_.filename = file;
+
 """
   if p.module.s[cfsFrameDefines].len == 0:
     appcg(p.module, p.module.s[cfsFrameDefines], frameDefines, ["#"])
@@ -777,11 +833,10 @@ proc loadDynamicLib(m: BModule, lib: PLib) =
       var p = newProc(nil, m)
       p.options.excl optStackTrace
       p.flags.incl nimErrorFlagDisabled
-      var dest: TLoc
-      initLoc(dest, locTemp, lib.path, OnStack)
+      var dest: TLoc = initLoc(locTemp, lib.path, OnStack)
       dest.r = getTempName(m)
       appcg(m, m.s[cfsDynLibInit],"$1 $2;$n",
-           [getTypeDesc(m, lib.path.typ, skVar), rdLoc(dest)])
+           [getTypeDesc(m, lib.path.typ, dkVar), rdLoc(dest)])
       expr(p, lib.path, dest)
 
       m.s[cfsVars].add(p.s(cpsLocals))
@@ -813,15 +868,14 @@ proc symInDynamicLib(m: BModule, sym: PSym) =
   inc(m.labels, 2)
   if isCall:
     let n = lib.path
-    var a: TLoc
-    initLocExpr(m.initProc, n[0], a)
+    var a: TLoc = initLocExpr(m.initProc, n[0])
     var params = rdLoc(a) & "("
     for i in 1..<n.len-1:
-      initLocExpr(m.initProc, n[i], a)
+      a = initLocExpr(m.initProc, n[i])
       params.add(rdLoc(a))
       params.add(", ")
     let load = "\t$1 = ($2) ($3$4));$n" %
-        [tmp, getTypeDesc(m, sym.typ, skVar), params, makeCString($extname)]
+        [tmp, getTypeDesc(m, sym.typ, dkVar), params, makeCString($extname)]
     var last = lastSon(n)
     if last.kind == nkHiddenStdConv: last = last[1]
     internalAssert(m.config, last.kind == nkStrLit)
@@ -835,8 +889,8 @@ proc symInDynamicLib(m: BModule, sym: PSym) =
   else:
     appcg(m, m.s[cfsDynLibInit],
         "\t$1 = ($2) #nimGetProcAddr($3, $4);$n",
-        [tmp, getTypeDesc(m, sym.typ, skVar), lib.name, makeCString($extname)])
-  m.s[cfsVars].addf("$2 $1;$n", [sym.loc.r, getTypeDesc(m, sym.loc.t, skVar)])
+        [tmp, getTypeDesc(m, sym.typ, dkVar), lib.name, makeCString($extname)])
+  m.s[cfsVars].addf("$2 $1;$n", [sym.loc.r, getTypeDesc(m, sym.loc.t, dkVar)])
 
 proc varInDynamicLib(m: BModule, sym: PSym) =
   var lib = sym.annex
@@ -848,9 +902,9 @@ proc varInDynamicLib(m: BModule, sym: PSym) =
   inc(m.labels, 2)
   appcg(m, m.s[cfsDynLibInit],
       "$1 = ($2*) #nimGetProcAddr($3, $4);$n",
-      [tmp, getTypeDesc(m, sym.typ, skVar), lib.name, makeCString($extname)])
+      [tmp, getTypeDesc(m, sym.typ, dkVar), lib.name, makeCString($extname)])
   m.s[cfsVars].addf("$2* $1;$n",
-      [sym.loc.r, getTypeDesc(m, sym.loc.t, skVar)])
+      [sym.loc.r, getTypeDesc(m, sym.loc.t, dkVar)])
 
 proc symInDynamicLibPartial(m: BModule, sym: PSym) =
   sym.loc.r = mangleDynLibProc(sym)
@@ -881,7 +935,9 @@ proc cgsymValue(m: BModule, name: string): Rope =
     result.addActualSuffixForHCR(m.module, sym)
 
 proc generateHeaders(m: BModule) =
-  m.s[cfsHeaders].add("\L#include \"nimbase.h\"\L")
+  var nimbase = m.config.nimbasePattern
+  if nimbase == "": nimbase = "nimbase.h"
+  m.s[cfsHeaders].addf("\L#include \"$1\"\L", [nimbase])
 
   for it in m.headerFiles:
     if it[0] == '#':
@@ -930,11 +986,19 @@ proc closureSetup(p: BProc, prc: PSym) =
     linefmt(p, cpsStmts, "$1 = ($2) ClE_0;$n",
             [rdLoc(env.loc), getTypeDesc(p.module, env.typ)])
 
+const harmless = {nkConstSection, nkTypeSection, nkEmpty, nkCommentStmt, nkTemplateDef,
+                  nkMacroDef, nkMixinStmt, nkBindStmt, nkFormalParams} +
+                  declarativeDefs
+
 proc containsResult(n: PNode): bool =
   result = false
   case n.kind
-  of nkEmpty..pred(nkSym), succ(nkSym)..nkNilLit, nkFormalParams:
+  of succ(nkEmpty)..pred(nkSym), succ(nkSym)..nkNilLit, harmless:
     discard
+  of nkReturnStmt:
+    for i in 0..<n.len:
+      if containsResult(n[i]): return true
+    result = n.len > 0 and n[0].kind == nkEmpty
   of nkSym:
     if n.sym.kind == skResult:
       result = true
@@ -942,11 +1006,8 @@ proc containsResult(n: PNode): bool =
     for i in 0..<n.len:
       if containsResult(n[i]): return true
 
-const harmless = {nkConstSection, nkTypeSection, nkEmpty, nkCommentStmt, nkTemplateDef,
-                  nkMacroDef, nkMixinStmt, nkBindStmt, nkFormalParams} +
-                  declarativeDefs
-
 proc easyResultAsgn(n: PNode): PNode =
+  result = nil
   case n.kind
   of nkStmtList, nkStmtListExpr:
     var i = 0
@@ -1071,14 +1132,14 @@ proc allPathsAsgnResult(n: PNode): InitResultEnum =
 proc getProcTypeCast(m: BModule, prc: PSym): Rope =
   result = getTypeDesc(m, prc.loc.t)
   if prc.typ.callConv == ccClosure:
-    var rettype, params: Rope
+    var rettype, params: Rope = ""
     var check = initIntSet()
     genProcParams(m, prc.typ, rettype, params, check)
     result = "$1(*)$2" % [rettype, params]
 
 proc genProcBody(p: BProc; procBody: PNode) =
   genStmts(p, procBody) # modifies p.locals, p.init, etc.
-  if {nimErrorFlagAccessed, nimErrorFlagDeclared} * p.flags == {nimErrorFlagAccessed}:
+  if {nimErrorFlagAccessed, nimErrorFlagDeclared, nimErrorFlagDisabled} * p.flags == {nimErrorFlagAccessed}:
     p.flags.incl nimErrorFlagDeclared
     p.blocks[0].sections[cpsLocals].add(ropecg(p.module, "NIM_BOOL* nimErr_;$n", []))
     p.blocks[0].sections[cpsInit].add(ropecg(p.module, "nimErr_ = #nimErrorFlag();$n", []))
@@ -1086,10 +1147,14 @@ proc genProcBody(p: BProc; procBody: PNode) =
 proc isNoReturn(m: BModule; s: PSym): bool {.inline.} =
   sfNoReturn in s.flags and m.config.exc != excGoto
 
-proc genProcAux(m: BModule, prc: PSym) =
+proc genProcAux*(m: BModule, prc: PSym) =
   var p = newProc(prc, m)
   var header = newRopeAppender()
-  genProcHeader(m, prc, header)
+  let isCppMember = m.config.backend == backendCpp and sfCppMember * prc.flags != {}
+  if isCppMember:
+    genMemberProcHeader(m, prc, header)
+  else:
+    genProcHeader(m, prc, header)
   var returnStmt: Rope = ""
   assert(prc.ast != nil)
 
@@ -1097,24 +1162,39 @@ proc genProcAux(m: BModule, prc: PSym) =
   if sfInjectDestructors in prc.flags:
     procBody = injectDestructorCalls(m.g.graph, m.idgen, prc, procBody)
 
+  let tmpInfo = prc.info
+  discard freshLineInfo(p, prc.info)
+
   if sfPure notin prc.flags and prc.typ[0] != nil:
     if resultPos >= prc.ast.len:
       internalError(m.config, prc.info, "proc has no result symbol")
     let resNode = prc.ast[resultPos]
     let res = resNode.sym # get result symbol
-    if not isInvalidReturnType(m.config, prc.typ):
+    if not isInvalidReturnType(m.config, prc.typ) and sfConstructor notin prc.flags:
       if sfNoInit in prc.flags: incl(res.flags, sfNoInit)
       if sfNoInit in prc.flags and p.module.compileToCpp and (let val = easyResultAsgn(procBody); val != nil):
         var decl = localVarDecl(p, resNode)
-        var a: TLoc
-        initLocExprSingleUse(p, val, a)
+        var a: TLoc = initLocExprSingleUse(p, val)
         linefmt(p, cpsStmts, "$1 = $2;$n", [decl, rdLoc(a)])
       else:
         # declare the result symbol:
         assignLocalVar(p, resNode)
         assert(res.loc.r != "")
-        initLocalVar(p, res, immediateAsgn=false)
+        if p.config.selectedGC in {gcArc, gcAtomicArc, gcOrc} and
+            allPathsAsgnResult(procBody) == InitSkippable:
+          # In an ideal world the codegen could rely on injectdestructors doing its job properly
+          # and then the analysis step would not be required.
+          discard "result init optimized out"
+        else:
+          initLocalVar(p, res, immediateAsgn=false)
       returnStmt = ropecg(p.module, "\treturn $1;$n", [rdLoc(res.loc)])
+    elif sfConstructor in prc.flags:
+      fillLoc(resNode.sym.loc, locParam, resNode, "this", OnHeap)
+      let ty = resNode.sym.typ[0] #generate nim's ctor
+      for i in 1..<resNode.sym.ast.len:
+        let field = resNode.sym.ast[i]
+        genFieldObjConstr(p, ty, useTemp = false, isRef = false, 
+          field[0], field[1], check = nil, resNode.sym.loc, "(*this)", tmpInfo)
     else:
       fillResult(p.config, resNode, prc.typ)
       assignParam(p, res, prc.typ[0])
@@ -1139,13 +1219,15 @@ proc genProcAux(m: BModule, prc: PSym) =
   closureSetup(p, prc)
   genProcBody(p, procBody)
 
-  var generatedProc: Rope
+  prc.info = tmpInfo
+
+  var generatedProc: Rope = ""
   generatedProc.genCLineDir prc.info, m.config
   if isNoReturn(p.module, prc):
-    if hasDeclspec in extccomp.CC[p.config.cCompiler].props:
+    if hasDeclspec in extccomp.CC[p.config.cCompiler].props and not isCppMember:
       header = "__declspec(noreturn) " & header
   if sfPure in prc.flags:
-    if hasDeclspec in extccomp.CC[p.config.cCompiler].props:
+    if hasDeclspec in extccomp.CC[p.config.cCompiler].props and not isCppMember:
       header = "__declspec(naked) " & header
     generatedProc.add ropecg(p.module, "$1 {$n$2$3$4}$N$N",
                          [header, p.s(cpsLocals), p.s(cpsInit), p.s(cpsStmts)])
@@ -1190,7 +1272,7 @@ proc requiresExternC(m: BModule; sym: PSym): bool {.inline.} =
 
 proc genProcPrototype(m: BModule, sym: PSym) =
   useHeader(m, sym)
-  if lfNoDecl in sym.loc.flags: return
+  if lfNoDecl in sym.loc.flags or sfCppMember * sym.flags != {}: return
   if lfDynamicLib in sym.loc.flags:
     if sym.itemId.module != m.module.position and
         not containsOrIncl(m.declaredThings, sym.id):
@@ -1226,6 +1308,20 @@ proc genProcNoForward(m: BModule, prc: PSym) =
   if lfNoDecl in prc.loc.flags:
     fillProcLoc(m, prc.ast[namePos])
     genProcPrototype(m, prc)
+  elif lfDynamicLib in prc.loc.flags:
+    var q = findPendingModule(m, prc)
+    fillProcLoc(q, prc.ast[namePos])
+    genProcPrototype(m, prc)
+    if q != nil and not containsOrIncl(q.declaredThings, prc.id):
+      symInDynamicLib(q, prc)
+      # register the procedure even though it is in a different dynamic library and will not be
+      # reloadable (and has no _actual suffix) - other modules will need to be able to get it through
+      # the hcr dynlib (also put it in the DynLibInit section - right after it gets loaded)
+      if isReloadable(q, prc):
+        q.s[cfsDynLibInit].addf("\t$1 = ($2) hcrRegisterProc($3, \"$1\", (void*)$1);$n",
+            [prc.loc.r, getTypeDesc(q, prc.loc.t), getModuleDllPath(m, q.module)])
+    else:
+      symInDynamicLibPartial(m, prc)
   elif prc.typ.callConv == ccInline:
     # We add inline procs to the calling module to enable C based inlining.
     # This also means that a check with ``q.declaredThings`` is wrong, we need
@@ -1244,20 +1340,6 @@ proc genProcNoForward(m: BModule, prc: PSym) =
       #  prc.loc.r = mangleName(m, prc)
       genProcPrototype(m, prc)
       genProcAux(m, prc)
-  elif lfDynamicLib in prc.loc.flags:
-    var q = findPendingModule(m, prc)
-    fillProcLoc(q, prc.ast[namePos])
-    genProcPrototype(m, prc)
-    if q != nil and not containsOrIncl(q.declaredThings, prc.id):
-      symInDynamicLib(q, prc)
-      # register the procedure even though it is in a different dynamic library and will not be
-      # reloadable (and has no _actual suffix) - other modules will need to be able to get it through
-      # the hcr dynlib (also put it in the DynLibInit section - right after it gets loaded)
-      if isReloadable(q, prc):
-        q.s[cfsDynLibInit].addf("\t$1 = ($2) hcrRegisterProc($3, \"$1\", (void*)$1);$n",
-            [prc.loc.r, getTypeDesc(q, prc.loc.t), getModuleDllPath(m, q.module)])
-    else:
-      symInDynamicLibPartial(m, prc)
   elif sfImportc notin prc.flags:
     var q = findPendingModule(m, prc)
     fillProcLoc(q, prc.ast[namePos])
@@ -1321,14 +1403,14 @@ proc genVarPrototype(m: BModule, n: PNode) =
   if sym.owner.id != m.module.id:
     # else we already have the symbol generated!
     assert(sym.loc.r != "")
+    incl(m.declaredThings, sym.id)
     if sfThread in sym.flags:
       declareThreadVar(m, sym, true)
     else:
-      incl(m.declaredThings, sym.id)
       if sym.kind in {skLet, skVar, skField, skForVar} and sym.alignment > 0:
         m.s[cfsVars].addf "NIM_ALIGN($1) ", [rope(sym.alignment)]
       m.s[cfsVars].add(if m.hcrOn: "static " else: "extern ")
-      m.s[cfsVars].add(getTypeDesc(m, sym.loc.t, skVar))
+      m.s[cfsVars].add(getTypeDesc(m, sym.loc.t, dkVar))
       if m.hcrOn: m.s[cfsVars].add("*")
       if lfDynamicLib in sym.loc.flags: m.s[cfsVars].add("*")
       if sfRegister in sym.flags: m.s[cfsVars].add(" register")
@@ -1337,7 +1419,7 @@ proc genVarPrototype(m: BModule, n: PNode) =
       m.s[cfsVars].addf(" $1;$n", [sym.loc.r])
       if m.hcrOn: m.initProc.procSec(cpsLocals).addf(
         "\t$1 = ($2*)hcrGetGlobal($3, \"$1\");$n", [sym.loc.r,
-        getTypeDesc(m, sym.loc.t, skVar), getModuleDllPath(m, sym)])
+        getTypeDesc(m, sym.loc.t, dkVar), getModuleDllPath(m, sym)])
 
 proc addNimDefines(result: var Rope; conf: ConfigRef) {.inline.} =
   result.addf("#define NIM_INTBITS $1\L", [
@@ -1369,17 +1451,21 @@ proc getFileHeader(conf: ConfigRef; cfile: Cfile): Rope =
 
 proc getSomeNameForModule(conf: ConfigRef, filename: AbsoluteFile): Rope =
   ## Returns a mangled module name.
+  result = ""
   result.add mangleModuleName(conf, filename).mangle
 
 proc getSomeNameForModule(m: BModule): Rope =
   ## Returns a mangled module name.
   assert m.module.kind == skModule
   assert m.module.owner.kind == skPackage
+  result = ""
   result.add mangleModuleName(m.g.config, m.filename).mangle
 
 proc getSomeInitName(m: BModule, suffix: string): Rope =
   if not m.hcrOn:
     result = getSomeNameForModule(m)
+  else:
+    result = ""
   result.add suffix
 
 proc getInitName(m: BModule): Rope =
@@ -1398,10 +1484,10 @@ proc genMainProc(m: BModule) =
   ## this function is called in cgenWriteModules after all modules are closed,
   ## it means raising dependency on the symbols is too late as it will not propagate
   ## into other modules, only simple rope manipulations are allowed
-
-  var preMainCode: Rope
+  var preMainCode: Rope = ""
   if m.hcrOn:
     proc loadLib(handle: string, name: string): Rope =
+      result = ""
       let prc = magicsys.getCompilerProc(m.g.graph, name)
       assert prc != nil
       let n = newStrNode(nkStrLit, prc.annex.path.strVal)
@@ -1413,20 +1499,23 @@ proc genMainProc(m: BModule) =
                        [handle, strLit])
 
     preMainCode.add(loadLib("hcr_handle", "hcrGetProc"))
-    preMainCode.add("\tvoid* rtl_handle;\L")
-    preMainCode.add(loadLib("rtl_handle", "nimGC_setStackBottom"))
-    preMainCode.add(hcrGetProcLoadCode(m, "nimGC_setStackBottom", "nimrtl_", "rtl_handle", "nimGetProcAddr"))
-    preMainCode.add("\tinner = PreMain;\L")
-    preMainCode.add("\tinitStackBottomWith_actual((void *)&inner);\L")
-    preMainCode.add("\t(*inner)();\L")
+    if m.config.selectedGC in {gcArc, gcAtomicArc, gcOrc}:
+      preMainCode.add("\t$1PreMain();\L" % [rope m.config.nimMainPrefix])
+    else:
+      preMainCode.add("\tvoid* rtl_handle;\L")
+      preMainCode.add(loadLib("rtl_handle", "nimGC_setStackBottom"))
+      preMainCode.add(hcrGetProcLoadCode(m, "nimGC_setStackBottom", "nimrtl_", "rtl_handle", "nimGetProcAddr"))
+      preMainCode.add("\tinner = $1PreMain;\L" % [rope m.config.nimMainPrefix])
+      preMainCode.add("\tinitStackBottomWith_actual((void *)&inner);\L")
+      preMainCode.add("\t(*inner)();\L")
   else:
     preMainCode.add("\t$1PreMain();\L" % [rope m.config.nimMainPrefix])
 
-  var posixCmdLine: Rope
+  var posixCmdLine: Rope = ""
   if optNoMain notin m.config.globalOptions:
-    posixCmdLine.add "\tN_LIB_PRIVATE int cmdCount;\L"
-    posixCmdLine.add "\tN_LIB_PRIVATE char** cmdLine;\L"
-    posixCmdLine.add "\tN_LIB_PRIVATE char** gEnv;\L"
+    posixCmdLine.add "N_LIB_PRIVATE int cmdCount;\L"
+    posixCmdLine.add "N_LIB_PRIVATE char** cmdLine;\L"
+    posixCmdLine.add "N_LIB_PRIVATE char** gEnv;\L"
 
   const
     # The use of a volatile function pointer to call Pre/NimMainInner
@@ -1439,15 +1528,15 @@ proc genMainProc(m: BModule) =
       "}$N$N" &
       "$4" &
       "N_LIB_PRIVATE void $3PreMain(void) {$N" &
-      "\t##if $5$N" & # 1 for volatile call, 0 for non-volatile
+      "##if $5$N" & # 1 for volatile call, 0 for non-volatile
       "\tvoid (*volatile inner)(void);$N" &
       "\tinner = $3PreMainInner;$N" &
       "$1" &
       "\t(*inner)();$N" &
-      "\t##else$N" &
+      "##else$N" &
       "$1" &
       "\t$3PreMainInner();$N" &
-      "\t##endif$N" &
+      "##endif$N" &
       "}$N$N"
 
     MainProcs =
@@ -1462,17 +1551,17 @@ proc genMainProc(m: BModule) =
 
     NimMainProc =
       "N_CDECL(void, $5NimMain)(void) {$N" &
-      "\t##if $6$N" & # 1 for volatile call, 0 for non-volatile
+      "##if $6$N" & # 1 for volatile call, 0 for non-volatile
       "\tvoid (*volatile inner)(void);$N" &
       "$4" &
       "\tinner = $5NimMainInner;$N" &
       "$2" &
       "\t(*inner)();$N" &
-      "\t##else$N" &
+      "##else$N" &
       "$4" &
       "$2" &
       "\t$5NimMainInner();$N" &
-      "\t##endif$N" &
+      "##endif$N" &
       "}$N$N"
 
     NimMainBody = NimMainInner & NimMainProc
@@ -1503,7 +1592,7 @@ proc genMainProc(m: BModule) =
     WinCDllMain =
       "BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fwdreason, $N" &
       "                    LPVOID lpvReserved) {$N" &
-      "\tif(fwdreason == DLL_PROCESS_ATTACH) {$N" & MainProcs & "}$N" &
+      "\tif (fwdreason == DLL_PROCESS_ATTACH) {$N" & MainProcs & "\t}$N" &
       "\treturn 1;$N}$N$N"
 
     PosixNimDllMain = WinNimDllMain
@@ -1537,11 +1626,11 @@ proc genMainProc(m: BModule) =
     m.includeHeader("<libc/component.h>")
 
   let initStackBottomCall =
-    if m.config.target.targetOS == osStandalone or m.config.selectedGC in {gcNone, gcArc, gcOrc}: "".rope
+    if m.config.target.targetOS == osStandalone or m.config.selectedGC in {gcNone, gcArc, gcAtomicArc, gcOrc}: "".rope
     else: ropecg(m, "\t#initStackBottomWith((void *)&inner);$N", [])
   inc(m.labels)
 
-  let isVolatile = if m.config.selectedGC notin {gcNone, gcArc, gcOrc}: "1" else: "0"
+  let isVolatile = if m.config.selectedGC notin {gcNone, gcArc, gcAtomicArc, gcOrc}: "1" else: "0"
   appcg(m, m.s[cfsProcs], PreMainBody, [m.g.mainDatInit, m.g.otherModsInit, m.config.nimMainPrefix, posixCmdLine, isVolatile])
 
   if m.config.target.targetOS == osWindows and
@@ -1681,7 +1770,7 @@ proc registerModuleToMain(g: BModuleList; m: BModule) =
   if sfSystemModule in m.module.flags:
     if emulatedThreadVars(m.config) and m.config.target.targetOS != osStandalone:
       g.mainDatInit.add(ropecg(m, "\t#initThreadVarsEmulation();$N", []))
-    if m.config.target.targetOS != osStandalone and m.config.selectedGC notin {gcNone, gcArc, gcOrc}:
+    if m.config.target.targetOS != osStandalone and m.config.selectedGC notin {gcNone, gcArc, gcAtomicArc, gcOrc}:
       g.mainDatInit.add(ropecg(m, "\t#initStackBottomWith((void *)&inner);$N", []))
 
   if m.s[cfsInitProc].len > 0:
@@ -1732,10 +1821,10 @@ proc hcrGetProcLoadCode(m: BModule, sym, prefix, handle, getProcFunc: string): R
   prc.typ.sym = nil
 
   if not containsOrIncl(m.declaredThings, prc.id):
-    m.s[cfsVars].addf("static $2 $1;$n", [prc.loc.r, getTypeDesc(m, prc.loc.t, skVar)])
+    m.s[cfsVars].addf("static $2 $1;$n", [prc.loc.r, getTypeDesc(m, prc.loc.t, dkVar)])
 
   result = "\t$1 = ($2) $3($4, $5);$n" %
-      [tmp, getTypeDesc(m, prc.typ, skVar), getProcFunc.rope, handle.rope, makeCString(prefix & sym)]
+      [tmp, getTypeDesc(m, prc.typ, dkVar), getProcFunc.rope, handle.rope, makeCString(prefix & sym)]
 
 proc genInitCode(m: BModule) =
   ## this function is called in cgenWriteModules after all modules are closed,
@@ -1811,13 +1900,13 @@ proc genInitCode(m: BModule) =
     if beforeRetNeeded in m.initProc.flags:
       prc.add("\tBeforeRet_: ;\n")
 
-    if sfMainModule in m.module.flags and m.config.exc == excGoto:
+    if m.config.exc == excGoto:
       if getCompilerProc(m.g.graph, "nimTestErrorFlag") != nil:
         m.appcg(prc, "\t#nimTestErrorFlag();$n", [])
 
     if optStackTrace in m.initProc.options and preventStackTrace notin m.flags:
       prc.add(deinitFrame(m.initProc))
-  elif sfMainModule in m.module.flags and m.config.exc == excGoto:
+  elif m.config.exc == excGoto:
     if getCompilerProc(m.g.graph, "nimTestErrorFlag") != nil:
       m.appcg(prc, "\t#nimTestErrorFlag();$n", [])
 
@@ -1874,8 +1963,6 @@ proc genModule(m: BModule, cfile: Cfile): Rope =
     openNamespaceNim(m.config.cppCustomNamespace, result)
   if m.s[cfsFrameDefines].len > 0:
     result.add(m.s[cfsFrameDefines])
-  else:
-    result.add("#define nimfr_(x, y)\n#define nimln_(x, y)\n")
 
   for i in cfsForwardTypes..cfsProcs:
     if m.s[i].len > 0:
@@ -1919,7 +2006,7 @@ proc rawNewModule(g: BModuleList; module: PSym, filename: AbsoluteFile): BModule
   result.preInitProc = newProc(nil, result)
   result.preInitProc.flags.incl nimErrorFlagDisabled
   result.preInitProc.labels = 100_000 # little hack so that unique temporaries are generated
-  initNodeTable(result.dataCache)
+  result.dataCache = initNodeTable()
   result.typeStack = @[]
   result.typeNodesName = getTempName(result)
   result.nimTypesName = getTempName(result)
@@ -2024,6 +2111,11 @@ proc genTopLevelStmt*(m: BModule; n: PNode) =
   if sfInjectDestructors in m.module.flags:
     transformedN = injectDestructorCalls(m.g.graph, m.idgen, m.module, transformedN)
 
+  if sfMainModule in m.module.flags:
+    let moduleCon = initModuleCon(m.g.graph, m.config, m.module)
+    var procCon = initProcCon(moduleCon, nil)
+    genCode(procCon, transformedN)
+
   if m.hcrOn:
     addHcrInitGuards(m.initProc, transformedN, m.inHcrInitGuard)
   else:
@@ -2094,8 +2186,9 @@ proc updateCachedModule(m: BModule) =
   cf.flags = {CfileFlag.Cached}
   addFileToCompile(m.config, cf)
 
-proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode) =
+proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode): PNode =
   ## Also called from IC.
+  result = nil
   if sfMainModule in m.module.flags:
     # phase ordering problem here: We need to announce this
     # dependency to 'nimTestErrorFlag' before system.c has been written to disk.
@@ -2116,7 +2209,10 @@ proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode) =
 
     if m.hcrOn:
       # make sure this is pulled in (meaning hcrGetGlobal() is called for it during init)
-      cgsym(m, "programResult")
+      let sym = magicsys.getCompilerProc(m.g.graph, "programResult")
+      # ignore when not available, could be a module imported early in `system`
+      if sym != nil:
+        cgsymImpl m, sym
       if m.inHcrInitGuard:
         endBlock(m.initProc)
 
@@ -2133,15 +2229,14 @@ proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode) =
         cgsym(m, "rawWrite")
 
       # raise dependencies on behalf of genMainProc
-      if m.config.target.targetOS != osStandalone and m.config.selectedGC notin {gcNone, gcArc, gcOrc}:
+      if m.config.target.targetOS != osStandalone and m.config.selectedGC notin {gcNone, gcArc, gcAtomicArc, gcOrc}:
         cgsym(m, "initStackBottomWith")
       if emulatedThreadVars(m.config) and m.config.target.targetOS != osStandalone:
         cgsym(m, "initThreadVarsEmulation")
 
       if m.g.forwardedProcs.len == 0:
         incl m.flags, objHasKidsValid
-      let disp = generateMethodDispatchers(graph)
-      for x in disp: genProcAux(m, x.sym)
+      result = generateMethodDispatchers(graph, m.idgen)
 
   let mm = m
   m.g.modulesClosed.add mm

compiler/cgendata.nim

@@ -193,15 +193,17 @@ 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

@@ -44,6 +44,8 @@ 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
@@ -62,6 +64,7 @@ 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:
     return
@@ -113,7 +116,7 @@ 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
@@ -127,7 +130,7 @@ proc createDispatcher(s: PSym; g: ModuleGraph; idgen: IdGenerator): PSym =
   disp.loc.r = ""
   if s.typ[0] != 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 +152,7 @@ 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
   for i in 0..<g.methods.len:
     let disp = g.methods[i].dispatcher
     case sameMethodBucket(disp, s, multimethods = optMultiMethods in g.config.globalOptions)
@@ -178,6 +181,7 @@ proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
 
 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):
@@ -186,6 +190,7 @@ proc relevantCol(methods: seq[PSym], col: int): bool =
         return true
 
 proc cmpSignatures(a, b: PSym, relevantCols: IntSet): int =
+  result = 0
   for col in 1..<a.typ.len:
     if contains(relevantCols, col):
       var aa = skipTypes(a.typ[col], skipPtrs)
@@ -213,7 +218,7 @@ 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 genDispatcher(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet; idgen: IdGenerator): PSym =
   var base = methods[0].ast[dispatcherPos].sym
   result = base
   var paramLen = base.typ.len
@@ -272,7 +277,7 @@ 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 =
+proc generateMethodDispatchers*(g: ModuleGraph, idgen: IdGenerator): PNode =
   result = newNode(nkStmtList)
   for bucket in 0..<g.methods.len:
     var relevantCols = initIntSet()
@@ -282,4 +287,4 @@ proc generateMethodDispatchers*(g: ModuleGraph): PNode =
         # 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))
+    result.add newSymNode(genDispatcher(g, g.methods[bucket].methods, relevantCols, idgen))

compiler/closureiters.nim

@@ -183,7 +183,7 @@ 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
   assert(not typ.isNil)
 
@@ -258,8 +258,9 @@ proc hasYields(n: PNode): bool =
   of nkYieldStmt:
     result = true
   of nkSkip:
-    discard
+    result = false
   else:
+    result = false
     for c in n:
       if c.hasYields:
         result = true
@@ -325,7 +326,7 @@ 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,
@@ -388,19 +389,22 @@ 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
@@ -495,7 +499,7 @@ 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)
@@ -855,7 +859,9 @@ 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)
 
@@ -1348,7 +1354,7 @@ 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 +1365,7 @@ 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 +1396,7 @@ 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])
@@ -1431,9 +1438,9 @@ proc transformClosureIterator*(g: ModuleGraph; idgen: IdGenerator; fn: PSym, n:
     # 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
@@ -1466,9 +1473,10 @@ proc transformClosureIterator*(g: ModuleGraph; idgen: IdGenerator; fn: PSym, n:
   result = ctx.transformStateAssignments(result)
   result = ctx.wrapIntoStateLoop(result)
 
-  # echo "TRANSFORM TO STATES: "
-  # echo renderTree(result)
+  when false:
+    echo "TRANSFORM TO STATES: "
+    echo renderTree(result)
 
-  # echo "exception table:"
-  # for i, e in ctx.exceptionTable:
-  #   echo i, " -> ", e
+    echo "exception table:"
+    for i, e in ctx.exceptionTable:
+      echo i, " -> ", e

compiler/cmdlinehelper.nim

@@ -7,7 +7,7 @@
 #    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,

compiler/commands.nim

@@ -184,7 +184,7 @@ 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
@@ -238,9 +238,9 @@ 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 +262,18 @@ 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 +283,9 @@ 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 +294,12 @@ 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 +345,14 @@ 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 +394,8 @@ 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:
@@ -515,14 +532,7 @@ 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 +542,11 @@ 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 +572,17 @@ 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")
@@ -587,8 +606,8 @@ proc processMemoryManagementOption(switch, arg: string, pass: TCmdLinePass,
 
 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 +622,17 @@ 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":
@@ -651,6 +670,9 @@ 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 +783,10 @@ 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 +823,7 @@ 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 +847,8 @@ 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 +889,28 @@ 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 +920,9 @@ 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 +1102,6 @@ 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 +1115,8 @@ 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 +1131,8 @@ 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 +1159,10 @@ 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 +1173,6 @@ 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

@@ -13,8 +13,6 @@
 
 import ast, astalgo, semdata, lookups, lineinfos, idents, msgs, renderer, types, intsets
 
-from magicsys import addSonSkipIntLit
-
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -27,24 +25,12 @@ 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)
+  let s = newSym(skType, getIdent(c.cache, "Self"), c.idgen, ow, info)
   s.typ = newType(tyTypeDesc, nextTypeId(c.idgen), ow)
   s.typ.flags.incl {tfUnresolved, tfPacked}
   s.typ.add newType(tyEmpty, nextTypeId(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 +48,7 @@ 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
@@ -121,8 +107,11 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
         for i in 0..<a.len:
           if not matchType(c, f[i], a[i], m): return false
         return true
+      else:
+        result = false
 
   of tyGenericInvocation:
+    result = false
     if a.kind == tyGenericInst and a[0].kind == tyGenericBody:
       if sameType(f[0], a[0]) and f.len == a.len-1:
         for i in 1 ..< f.len:
@@ -156,15 +145,17 @@ 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[0], a[0], m)
     elif m.magic == mArrPut:
-      result = matchType(c, f.sons[0], a, m)
+      result = matchType(c, f[0], a, m)
     else:
       result = false
   of tyEnum, tyObject, tyDistinct:
@@ -185,6 +176,7 @@ 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:
+    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:
@@ -209,6 +201,7 @@ proc matchType(c: PContext; f, a: PType; m: var MatchCon): bool =
       if not result:
         m.inferred.setLen oldLen
     else:
+      result = false
       for i in 0..<f.len:
         result = matchType(c, f[i], a, m)
         if result: break # and remember the binding!
@@ -257,7 +250,7 @@ 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[0], candidate.typ[0], m):
     m.inferred.setLen oldLen
     return false
 
@@ -306,6 +299,8 @@ 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

compiler/condsyms.nim

@@ -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
@@ -147,10 +145,19 @@ proc initDefines*(symbols: StringTableRef) =
   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("nimUseStrictDefs")
+  defineSymbol("nimHasNolineTooLong")

compiler/depends.nim

@@ -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

@@ -60,6 +60,7 @@ 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 +112,7 @@ 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 +129,6 @@ 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
@@ -263,8 +260,9 @@ 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
@@ -385,7 +383,8 @@ proc genCall(c: var Con; n: PNode) =
       # 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)
@@ -467,7 +466,7 @@ 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 +492,7 @@ 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

@@ -112,13 +112,16 @@ 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 +170,7 @@ 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 +216,16 @@ 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 +264,16 @@ 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
@@ -308,8 +325,9 @@ 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 +348,7 @@ 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 +373,7 @@ 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 +433,21 @@ 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 +476,7 @@ 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 +492,8 @@ 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 +585,13 @@ 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 +607,9 @@ 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 +628,6 @@ 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 +643,7 @@ 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 +657,7 @@ 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 +668,7 @@ $#
 #[
 $#
 ]#
+import std/assertions
 import $#
 $#
 """ % [comment, d.filename.quoted, code2]
@@ -705,7 +735,7 @@ 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 +951,17 @@ 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(), '/')
@@ -970,7 +1003,7 @@ proc toLangSymbol(k: TSymKind, n: PNode, baseName: string): LangSymbol =
   result.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:
@@ -995,8 +1028,7 @@ 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,
+      var r: TSrcGen = initTokRender(genNode, {renderNoBody, renderNoComments,
         renderNoPragmas, renderNoProcDefs, renderExpandUsing})
       var kind = tkEof
       while true:
@@ -1017,15 +1049,14 @@ 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,
+  var r: TSrcGen = initTokRender(n, {renderNoBody, renderNoComments, renderDocComments,
     renderNoPragmas, renderNoProcDefs, renderExpandUsing})
   while true:
     getNextTok(r, kind, literal)
@@ -1060,7 +1091,8 @@ 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,
@@ -1123,13 +1155,16 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
   if k == skType and nameNode.kind == nkSym:
     d.types.strTableAdd nameNode.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})
+    renderFlags = {renderNoBody, renderNoComments, renderDocComments, renderExpandUsing}
+  if nonExports:
+    renderFlags.incl renderNonExportedFields
+  r = initTokRender(n, renderFlags)
   result.json = %{ "name": %name, "type": %($k), "line": %n.info.line.int,
                    "col": %n.info.col}
   if comm != nil:
@@ -1161,9 +1196,9 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind): JsonItem =
       result.json["signature"]["genericParams"] = newJArray()
       for genericParam in n[genericParamsPos]:
         var param = %{"name": %($genericParam)}
-        if genericParam.sym.typ.sons.len > 0:
+        if genericParam.sym.typ.len > 0:
           param["types"] = newJArray()
-        for kind in genericParam.sym.typ.sons:
+        for kind in genericParam.sym.typ:
           param["types"].add %($kind)
         result.json["signature"]["genericParams"].add param
   if optGenIndex in d.conf.globalOptions:
@@ -1258,6 +1293,8 @@ 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 +1317,8 @@ 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 +1332,8 @@ 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
@@ -1366,7 +1407,7 @@ 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 +1492,8 @@ 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 +1516,7 @@ 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 +1542,7 @@ 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 +1555,7 @@ 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 +1587,14 @@ 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 +1657,7 @@ 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 +1688,7 @@ 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 +1739,7 @@ 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 +1797,7 @@ 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,
@@ -1767,7 +1809,7 @@ proc writeOutputJson*(d: PDoc, useWarning = false) =
   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 +1843,16 @@ 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 +1871,7 @@ 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 +1923,7 @@ 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

@@ -6,12 +6,12 @@ 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)
@@ -56,6 +56,7 @@ 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
@@ -67,12 +68,12 @@ proc searchObjCase(t: PType; field: PSym): PNode =
   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)

compiler/evalffi.nim

@@ -11,7 +11,7 @@
 
 import ast, types, options, tables, dynlib, msgs, lineinfos
 from os import getAppFilename
-import pkg/libffi
+import libffi/libffi
 
 when defined(windows):
   const libcDll = "msvcrt.dll"
@@ -37,9 +37,10 @@ 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 +62,7 @@ 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:
@@ -108,6 +109,7 @@ 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))[]
@@ -132,6 +134,8 @@ proc packSize(conf: ConfigRef, v: PNode, typ: PType): int =
       result = sizeof(pointer)
     elif v.len != 0:
       result = v.len * packSize(conf, v[0], typ[1])
+    else:
+      result = 0
   else:
     result = getSize(conf, typ).int
 
@@ -140,6 +144,7 @@ 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 +159,8 @@ 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}
@@ -356,6 +362,7 @@ 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))
@@ -381,6 +388,7 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
       n[0] = unpack(conf, p, typ.lastSon, 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)
@@ -398,6 +406,7 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
     result = unpack(conf, x, typ.lastSon, 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 =
@@ -424,7 +433,7 @@ proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =
   internalAssert conf, call[0].kind == nkPtrLit
 
   var cif: TCif
-  var sig: ParamList
+  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)
@@ -436,7 +445,7 @@ proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =
               mapType(conf, typ[0]), 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
@@ -464,7 +473,7 @@ proc callForeignFunction*(conf: ConfigRef, fn: PNode, fntyp: PType,
   internalAssert conf, fn.kind == nkPtrLit
 
   var cif: TCif
-  var sig: ParamList
+  var sig: ParamList = default(ParamList)
   for i in 0..len-1:
     var aTyp = args[i+start].typ
     if aTyp.isNil:
@@ -478,7 +487,7 @@ 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

@@ -10,7 +10,7 @@
 ## Template evaluation engine. Now hygienic.
 
 import
-  strutils, options, ast, astalgo, msgs, renderer, lineinfos, idents
+  strutils, options, ast, astalgo, msgs, renderer, lineinfos, idents, trees
 
 type
   TemplCtx = object
@@ -49,7 +49,7 @@ proc evalTemplateAux(templ, actual: PNode, c: var TemplCtx, result: PNode) =
         internalAssert c.config, sfGenSym in s.flags or s.kind == skType
         var x = PSym(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:
@@ -187,7 +187,7 @@ proc evalTemplate*(n: PNode, tmpl, genSymOwner: PSym;
   ctx.genSymOwner = genSymOwner
   ctx.config = conf
   ctx.ic = ic
-  initIdTable(ctx.mapping)
+  ctx.mapping = initIdTable()
   ctx.instID = instID[]
   ctx.idgen = idgen
 

compiler/extccomp.nim

@@ -14,13 +14,15 @@
 
 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 ../dist/checksums/src/checksums/sha1
+
 type
   TInfoCCProp* = enum         # properties of the C compiler:
     hasSwitchRange,           # CC allows ranges in switch statements (GNU C)
@@ -484,6 +486,10 @@ 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 +538,7 @@ 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 +584,7 @@ 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 +648,7 @@ 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 +783,7 @@ 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 +839,10 @@ 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 +866,7 @@ 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 +889,15 @@ 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:
@@ -1017,8 +1028,9 @@ proc writeJsonBuildInstructions*(conf: ConfigRef) =
   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 +1046,7 @@ 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 +1059,8 @@ 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 +1070,7 @@ 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

@@ -201,17 +201,15 @@ 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

@@ -29,23 +29,30 @@ 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 +9,14 @@
 
 ## Module that implements ``gorge`` for the compiler.
 
-import msgs, std / sha1, os, osproc, streams, options,
+import msgs, os, osproc, streams, options,
   lineinfos, pathutils
 
 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 +29,11 @@ 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:
@@ -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:
@@ -981,7 +1099,7 @@ proc addFactLt*(m: var TModel; a, b: PNode) =
 
 proc settype(n: PNode): PType =
   result = newType(tySet, ItemId(module: -1, item: -1), n.typ.owner)
-  var idgen: IdGenerator
+  var idgen: IdGenerator = nil
   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

@@ -13,6 +13,8 @@ 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
 

compiler/ic/cbackend.nim

@@ -50,7 +50,10 @@ proc generateCodeForModule(g: ModuleGraph; m: var LoadedModule; alive: var Alive
     let n = unpackTree(g, m.module.position, m.fromDisk.topLevel, p)
     cgen.genTopLevelStmt(bmod, n)
 
-  finalCodegenActions(g, bmod, newNodeI(nkStmtList, m.module.info))
+  let disps = finalCodegenActions(g, bmod, newNodeI(nkStmtList, m.module.info))
+  if disps != nil:
+    for disp in disps:
+      genProcAux(bmod, disp.sym)
   m.fromDisk.backendFlags = cgen.whichInitProcs(bmod)
 
 proc replayTypeInfo(g: ModuleGraph; m: var LoadedModule; origin: FileIndex) =
@@ -98,7 +101,7 @@ 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:

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
 

compiler/ic/ic.nim

@@ -7,13 +7,15 @@
 #    distribution, for details about the copyright.
 #
 
-import hashes, tables, intsets, std/sha1
+import hashes, tables, intsets
 import packed_ast, bitabs, rodfiles
 import ".." / [ast, idents, lineinfos, msgs, ropes, options,
   pathutils, condsyms, packages, modulepaths]
 #import ".." / [renderer, astalgo]
 from os import removeFile, isAbsolute
 
+import ../../dist/checksums/src/checksums/sha1
+
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions, formatfloat]
 
@@ -357,7 +359,7 @@ 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 items t:
       p.types.add kid.storeType(c, m)
     c.addMissing t.sym
     p.sym = t.sym.safeItemId(c, m)
@@ -372,7 +374,7 @@ proc toPackedLib(l: PLib; c: var PackedEncoder; m: var PackedModule): PackedLib
   if l.isNil: return
   result.kind = l.kind
   result.generated = l.generated
-  result.isOverriden = l.isOverriden
+  result.isOverridden = l.isOverridden
   result.name = toLitId($l.name, m)
   storeNode(result, l, path)
 
@@ -390,7 +392,7 @@ 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 +413,7 @@ 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
@@ -811,6 +814,7 @@ 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 +834,7 @@ 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 +852,7 @@ 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)
 
@@ -872,6 +877,7 @@ 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 loadSym(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; s: PackedItemId): PSym =
   if s == nilItemId:
@@ -913,7 +919,7 @@ proc typeBodyFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
       result.attachedOps[op] = loadSym(c, g, si, item)
   result.typeInst = loadType(c, g, si, t.typeInst)
   for son in items t.types:
-    result.sons.add loadType(c, g, si, son)
+    result.addSon loadType(c, g, si, son)
   loadAstBody(t, n)
   when false:
     for gen, id in items t.methods:
@@ -1144,6 +1150,8 @@ 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 =
@@ -1161,11 +1169,15 @@ 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;
@@ -1198,7 +1210,7 @@ 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

compiler/ic/navigator.nim

@@ -34,7 +34,11 @@ proc isTracked(current, trackPos: PackedLineInfo, tokenLen: int): bool =
   if current.file == trackPos.file and current.line == trackPos.line:
     let col = trackPos.col
     if col >= current.col and col < current.col+tokenLen:
-      return true
+      result = true
+    else:
+      result = false
+  else:
+    result = false
 
 proc searchLocalSym(c: var NavContext; s: PackedSym; info: PackedLineInfo): bool =
   result = s.name != LitId(0) and

compiler/ic/packed_ast.nim

@@ -45,7 +45,7 @@ type
   PackedLib* = object
     kind*: TLibKind
     generated*: bool
-    isOverriden*: bool
+    isOverridden*: bool
     name*: LitId
     path*: NodeId
 
@@ -63,13 +63,15 @@ 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
@@ -304,6 +306,7 @@ 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):

compiler/ic/rodfiles.nim

@@ -215,7 +215,7 @@ proc storeHeader*(f: var RodFile) =
 proc loadHeader*(f: var RodFile) =
   ## 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 +231,14 @@ 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 +246,6 @@ 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/importer.nim

@@ -113,6 +113,7 @@ 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]
@@ -228,10 +229,15 @@ proc importForwarded(c: PContext, n: PNode, exceptSet: IntSet; fromMod: PSym; im
     for i in 0..n.safeLen-1:
       importForwarded(c, n[i], exceptSet, fromMod, importSet)
 
+proc addUnique[T](x: var seq[T], y: sink T) {.noSideEffect.} =
+  for i in 0..high(x):
+    if x[i] == y: return
+  x.add y
+    
 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")
@@ -245,6 +251,7 @@ 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)
@@ -301,6 +308,8 @@ proc myImportModule(c: PContext, n: var PNode, importStmtResult: PNode): PSym =
     suggestSym(c.graph, n.info, result, c.graph.usageSym, false)
     importStmtResult.add newSymNode(result, n.info)
     #newStrNode(toFullPath(c.config, f), n.info)
+  else:
+    result = nil
 
 proc afterImport(c: PContext, m: PSym) =
   # fixes bug #17510, for re-exported symbols
@@ -323,22 +332,24 @@ 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

@@ -36,6 +36,7 @@ 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 +67,11 @@ 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 +79,11 @@ 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
 
@@ -184,11 +185,16 @@ 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 '\''
@@ -210,8 +216,12 @@ proc makePtrType(c: var Con, baseType: PType): PType =
   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.len > 1 and op.typ[1].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 +259,20 @@ 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:
@@ -263,7 +283,14 @@ 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.} =
   #[
@@ -288,13 +315,13 @@ 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):
+    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 +335,9 @@ 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 +366,7 @@ 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 +394,7 @@ 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 +406,13 @@ 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):
+  if (not hasDestructor(c, n.typ)) and c.inEnsureMove == 0:
     assert n.kind != nkSym or not hasDestructor(c, n.sym.typ)
     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 +425,8 @@ 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
@@ -403,22 +434,47 @@ 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
+    let typ = n.typ.skipTypes({tyGenericInst, tyAlias, tySink})
+    let op = getAttachedOp(c.graph, typ, attachedDup)
+    if op != nil and tfHasOwned notin typ.flags:
+      if sfError in op.flags:
+        c.checkForErrorPragma(n.typ, n, "=dup")
+      else:
+        let copyOp = getAttachedOp(c.graph, typ, attachedAsgn)
+        if copyOp != nil and sfError in copyOp.flags and
+           sfOverridden notin op.flags:
+          c.checkForErrorPragma(n.typ, n, "=dup", inferredFromCopy = true)
+
+      let src = p(n, c, s, normal)
+      var newCall = newTreeIT(nkCall, src.info, src.typ,
+            newSymNode(op),
+            src)
+      c.finishCopy(newCall, n, isFromSink = true)
+      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 n.typ.skipTypes(abstractInst).kind != tyRef and c.inSpawn == 0:
       message(c.graph.config, n.info, hintPerformance,
         ("passing '$1' to a sink parameter introduces an implicit copy; " &
         "if possible, rearrange your program's control flow to prevent it") % $n)
+    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}:
+    if c.graph.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
       assert(not containsManagedMemory(n.typ))
     if n.typ.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
       localError(c.graph.config, n.info, "cannot create an implicit openArray copy to be passed to a sink parameter")
@@ -454,14 +510,14 @@ 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]
@@ -662,7 +718,27 @@ 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 +765,9 @@ 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 =
+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 +778,15 @@ 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
@@ -774,6 +858,12 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
       if mode == normal and isRefConstr:
         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
@@ -804,7 +894,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
 
       if n[0].kind == nkSym and n[0].sym.magic in {mNew, mNewFinalize}:
         result[0] = copyTree(n[0])
-        if c.graph.config.selectedGC in {gcHooks, gcArc, gcOrc}:
+        if c.graph.config.selectedGC in {gcHooks, gcArc, gcAtomicArc, gcOrc}:
           let destroyOld = c.genDestroy(result[1])
           result = newTree(nkStmtList, destroyOld, result)
       else:
@@ -859,7 +949,9 @@ 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 +979,6 @@ 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 +1035,7 @@ 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 +1049,12 @@ 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 +1078,9 @@ 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 +1095,22 @@ 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 +1119,61 @@ 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):
+          isLastRead(ri, c, s) and canBeMoved(c, dest.typ) and not isCursor(ri) and
+          not ({sfGlobal, sfPure} <= ri.sym.flags):
         # Rule 3: `=sink`(x, z); wasMoved(z)
-        let snk = c.genSink(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 +1184,12 @@ 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

@@ -78,6 +78,7 @@ Files: "lib"
 [Other]
 Files: "examples"
 Files: "dist/nimble"
+Files: "dist/checksums"
 
 Files: "tests"
 
@@ -91,6 +92,7 @@ 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"

compiler/int128.nim

@@ -171,6 +171,7 @@ 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) =
@@ -330,8 +331,8 @@ 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.udata[0] = cast[uint32](low)
@@ -360,6 +361,7 @@ proc `*=`*(a: var Int128, b: Int128) =
 import bitops
 
 proc fastLog2*(a: Int128): int =
+  result = 0
   if a.udata[3] != 0:
     return 96 + fastLog2(a.udata[3])
   if a.udata[2] != 0:
@@ -571,4 +573,4 @@ 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

@@ -21,6 +21,7 @@ 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 +37,7 @@ 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):
@@ -56,6 +57,7 @@ proc canAlias(arg, ret: PType; marker: var IntSet): bool =
     else:
       result = true
   of tyTuple:
+    result = false
     for i in 0..<ret.len:
       result = canAlias(arg, ret[i], marker)
       if result: break
@@ -72,6 +74,69 @@ 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[0] != nil:
+      result = containsDangerousRefAux(t[0].skipTypes(skipPtrs), marker)
+    if result == NotFound: result = containsDangerousRefAux(t.n, marker)
+  of tyGenericInst, tyDistinct, tyAlias, tySink:
+    result = containsDangerousRefAux(lastSon(t), marker)
+  of tyArray, tySet, tyTuple, tySequence:
+    for i in 0..<t.len:
+      result = containsDangerousRefAux(t[i], marker)
+      if result == Found: return result
+  else:
+    discard
+
+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 +145,15 @@ 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 +177,7 @@ 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 +186,12 @@ 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 +201,7 @@ 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 +214,12 @@ 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/lambdalifting.nim

@@ -140,7 +140,7 @@ proc createClosureIterStateType*(g: ModuleGraph; iter: PSym; idgen: IdGenerator)
   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 =
@@ -154,7 +154,7 @@ 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 = newSym(skResult, getIdent(g.cache, ":result"), idgen, iter, iter.info, {})
     result.typ = iter.typ[0]
     incl(result.flags, sfUsed)
     iter.ast.add newSymNode(result)
@@ -187,6 +187,8 @@ 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 +201,8 @@ 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
@@ -267,7 +271,7 @@ 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 +297,34 @@ 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 =
@@ -380,7 +385,7 @@ 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 +418,15 @@ 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)
@@ -444,12 +452,15 @@ proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
         let body = transformBody(c.graph, c.idgen, s, useCache)
         detectCapturedVars(body, s, c)
     let ow = s.skipGenericOwner
+    let innerClosure = innerProc and s.typ.callConv == ccClosure and not s.isIterator
+    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})
 
@@ -458,7 +469,7 @@ proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
             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 +486,12 @@ 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 +523,14 @@ 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 +540,8 @@ 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
@@ -545,7 +562,7 @@ proc accessViaEnvParam(g: ModuleGraph; n: PNode; owner: PSym): PNode =
   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)
@@ -569,7 +586,7 @@ 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 +670,7 @@ 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 +728,7 @@ 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;
@@ -792,6 +810,8 @@ 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:
@@ -936,14 +956,14 @@ 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
 

compiler/layouter.nim

@@ -510,7 +510,7 @@ 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 +528,7 @@ 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 +538,7 @@ 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

@@ -23,7 +23,6 @@ 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 +93,18 @@ 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
@@ -150,9 +148,11 @@ 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
@@ -178,7 +178,7 @@ proc initToken*(L: var Token) =
   L.tokType = tkInvalid
   L.iNumber = 0
   L.indent = 0
-  L.strongSpaceA = false
+  L.spacing = {}
   L.literal = ""
   L.fNumber = 0.0
   L.base = base10
@@ -191,7 +191,7 @@ proc fillToken(L: var Token) =
   L.tokType = tkInvalid
   L.iNumber = 0
   L.indent = 0
-  L.strongSpaceA = false
+  L.spacing = {}
   setLen(L.literal, 0)
   L.fNumber = 0.0
   L.base = base10
@@ -539,8 +539,8 @@ 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 +549,8 @@ 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 +737,6 @@ 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()
@@ -960,13 +956,15 @@ 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.
@@ -1011,6 +1009,7 @@ proc getPrecedence*(tok: Token): int =
   else: return -10
 
 proc newlineFollows*(L: Lexer): bool =
+  result = false
   var pos = L.bufpos
   while true:
     case L.buf[pos]
@@ -1077,7 +1076,6 @@ 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 +1094,6 @@ 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
@@ -1140,7 +1136,6 @@ 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 +1148,7 @@ 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
@@ -1164,8 +1159,7 @@ 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")
       inc(pos)
@@ -1187,7 +1181,7 @@ 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] == '#'):
@@ -1403,8 +1397,9 @@ 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
+  result = 0
+  var lex: Lexer = default(Lexer)
+  var tok: Token = default(Token)
   initToken(tok)
   openLexer(lex, fileIdx, inputstream, cache, config)
   var prevToken = tkEof

compiler/liftdestructors.nim

@@ -8,7 +8,7 @@
 #
 
 ## 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
@@ -34,6 +34,7 @@ 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)
@@ -49,9 +50,9 @@ 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:
@@ -82,14 +83,14 @@ 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:
@@ -139,11 +140,14 @@ proc genContainerOf(c: var TLiftCtx; objType: PType, field, x: PSym): PNode =
 proc destructorCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
   var destroy = newNodeIT(nkCall, x.info, op.typ[0])
   destroy.add(newSymNode(op))
-  destroy.add genAddr(c, x)
+  if op.typ[1].kind != tyVar:
+    destroy.add x
+  else:
+    destroy.add genAddr(c, x)
   if sfNeverRaises notin op.flags:
     c.canRaise = true
   if c.addMemReset:
-    result = newTree(nkStmtList, destroy, genBuiltin(c, mWasMoved,  "wasMoved", x))
+    result = newTree(nkStmtList, destroy, genBuiltin(c, mWasMoved,  "`=wasMoved`", x))
   else:
     result = destroy
 
@@ -158,8 +162,7 @@ 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:
@@ -243,7 +246,7 @@ 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 +255,7 @@ 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 +265,7 @@ 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
 
@@ -283,7 +286,7 @@ proc boolLit*(g: ModuleGraph; info: TLineInfo; value: bool): PNode =
   result.typ = getSysType(g, info, tyBool)
 
 proc getCycleParam(c: TLiftCtx): PNode =
-  assert c.kind == attachedAsgn
+  assert c.kind in {attachedAsgn, attachedDup}
   if c.fn.typ.len == 4:
     result = c.fn.typ.n.lastSon
     assert result.kind == nkSym
@@ -298,7 +301,7 @@ 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[1].kind == tyVar:
     result.add genAddr(c, x)
   else:
     result.add x
@@ -322,6 +325,9 @@ proc newOpCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
 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 +352,9 @@ 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 +362,12 @@ 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 +397,14 @@ 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 +427,7 @@ 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 +438,12 @@ 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 +460,12 @@ 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 +476,27 @@ 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 +506,7 @@ 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)
 
@@ -521,14 +553,28 @@ 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 +588,17 @@ 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 +624,22 @@ 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 +651,11 @@ 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.lastSon)
   of tyProc: result = t.callConv == ccClosure
   else: result = false
 
@@ -631,7 +683,7 @@ proc atomicRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   let elemType = t.lastSon
 
   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 +691,7 @@ 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 +750,16 @@ 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 +769,7 @@ 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 +803,21 @@ 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 +830,9 @@ 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:
@@ -773,7 +845,7 @@ proc weakrefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
       body.sons.insert(des, 0)
   of attachedDeepCopy: assert(false, "cannot happen")
   of attachedTrace: discard
-  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "wasMoved", x)
+  of attachedWasMoved: body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x)
 
 proc ownedRefOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   var actions = newNodeI(nkStmtList, c.info)
@@ -795,11 +867,13 @@ 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 +885,7 @@ 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 +900,11 @@ 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 +913,7 @@ 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 +925,13 @@ 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 +940,7 @@ 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 +949,7 @@ 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)
@@ -914,10 +995,25 @@ 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)
@@ -938,7 +1034,7 @@ proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   of tyOrdinal, tyRange, tyInferred,
      tyGenericInst, tyAlias, tySink:
     fillBody(c, lastSon(t), body, x, y)
-  of tyConcept, tyIterable: doAssert false
+  of tyConcept, tyIterable: raiseAssert "unreachable"
 
 proc produceSymDistinctType(g: ModuleGraph; c: PContext; typ: PType;
                             kind: TTypeAttachedOp; info: TLineInfo;
@@ -950,15 +1046,56 @@ proc produceSymDistinctType(g: ModuleGraph; c: PContext; typ: PType;
   result = getAttachedOp(g, baseType, kind)
   setAttachedOp(g, idgen.module, typ, kind, result)
 
+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, nextTypeId 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): 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 typ.kind in {tyRef, tyString, tySequence} and g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
+    dest.typ = typ
+  else:
+    dest.typ = makeVarType(typ.owner, typ, idgen)
+
   if kind == attachedTrace:
     src.typ = getSysType(g, info, tyPointer)
   else:
@@ -970,9 +1107,9 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
     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 +1121,9 @@ 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)
@@ -1004,22 +1144,25 @@ proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
   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[1].kind == tyVar: newDeref(newSymNode(dest)) else: newSymNode(dest)
+  let src = case kind
+            of {attachedDestructor, attachedWasMoved}: newNodeIT(nkSym, info, getSysType(g, info, tyPointer))
+            of attachedDup: newSymNode(result.typ.n[1].sym)
             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[1].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
@@ -1030,7 +1173,7 @@ 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)
 
@@ -1049,7 +1192,7 @@ 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 +1218,7 @@ 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)
@@ -1128,7 +1271,7 @@ 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

@@ -49,6 +49,7 @@ 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

@@ -7,8 +7,8 @@
 #    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
 
@@ -44,6 +44,7 @@ type
     errRstSandboxedDirective,
     errProveInit, # deadcode
     errGenerated,
+    errFailedMove,
     errUser,
     # warnings
     warnCannotOpenFile = "CannotOpenFile", warnOctalEscape = "OctalEscape",
@@ -83,16 +84,17 @@ type
     warnCstringConv = "CStringConv",
     warnPtrToCstringConv = "PtrToCstringConv",
     warnEffect = "Effect",
-    warnCastSizes = "CastSizes"
+    warnCastSizes = "CastSizes", # deadcode
+    warnAboveMaxSizeSet = "AboveMaxSizeSet",
     warnImplicitTemplateRedefinition = "ImplicitTemplateRedefinition",
     warnUnnamedBreak = "UnnamedBreak",
     warnStmtListLambda = "StmtListLambda",
     warnBareExcept = "BareExcept",
+    warnImplicitDefaultValue = "ImplicitDefaultValue",
     warnUser = "User",
     # hints
     hintSuccess = "Success", hintSuccessX = "SuccessX",
     hintCC = "CC",
-    hintLineTooLong = "LineTooLong",
     hintXDeclaredButNotUsed = "XDeclaredButNotUsed", hintDuplicateModuleImport = "DuplicateModuleImport",
     hintXCannotRaiseY = "XCannotRaiseY", hintConvToBaseNotNeeded = "ConvToBaseNotNeeded",
     hintConvFromXtoItselfNotNeeded = "ConvFromXtoItselfNotNeeded", hintExprAlwaysX = "ExprAlwaysX",
@@ -127,6 +129,7 @@ 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",
@@ -184,17 +187,18 @@ const
     warnCstringConv: "$1",
     warnPtrToCstringConv: "unsafe conversion to 'cstring' from '$1'; 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",
     warnUser: "$1",
     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",
@@ -244,7 +248,8 @@ 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}
   result[2] = result[3] - {hintStackTrace, hintExtendedContext, hintDeclaredLoc, hintProcessingStmt}
   result[1] = result[2] - {warnProveField, warnProveIndex,
     warnGcUnsafe, hintPath, hintDependency, hintCodeBegin, hintCodeEnd,
@@ -275,7 +280,7 @@ 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 +311,7 @@ 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 +342,8 @@ 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

@@ -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 +8,14 @@
 #
 
 # 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
+  renderer, lineinfos, modulegraphs, astmsgs, sets, wordrecg
 
 proc ensureNoMissingOrUnusedSymbols(c: PContext; scope: PScope)
 
@@ -72,7 +72,7 @@ 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 +94,6 @@ 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
 
@@ -265,6 +254,41 @@ proc searchInScopesFilterBy*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSy
         if s.kind in filter:
           result.add s
 
+proc isAmbiguous*(c: PContext, s: PIdent, filter: TSymKinds, sym: var PSym): bool =
+  result = false
+  block outer:
+    for scope in allScopes(c.currentScope):
+      var ti: TIdentIter
+      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, n: PNode): PSym =
   ## creates an error symbol to avoid cascading errors (for IDE support)
   var m = n
@@ -274,7 +298,7 @@ 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 = newSym(skError, ident, c.idgen, getCurrOwner(c), n.info, {})
   result.typ = errorType(c)
   incl(result.flags, sfDiscardable)
   # pretend it's from the top level scope to prevent cascading errors:
@@ -309,7 +333,7 @@ proc ensureNoMissingOrUnusedSymbols(c: PContext; scope: PScope) =
   var it: 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 +364,18 @@ 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 +421,12 @@ 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 +439,7 @@ 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) =
@@ -437,13 +463,6 @@ 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
 
@@ -474,7 +493,7 @@ 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 +508,9 @@ 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 +523,7 @@ 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"
@@ -546,12 +563,16 @@ 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 & "'" & 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 =
@@ -565,17 +586,17 @@ proc lookUp*(c: PContext, n: PNode): PSym =
   var amb = false
   case n.kind
   of nkIdent:
-    result = searchInScopes(c, n.ident, amb).skipAlias(n, c.config)
+    result = searchInScopes(c, n.ident, amb)
     if result == nil: result = errorUndeclaredIdentifierHint(c, n, n.ident)
   of nkSym:
     result = n.sym
   of nkAccQuoted:
     var ident = considerQuotedIdent(c, n)
-    result = searchInScopes(c, ident, amb).skipAlias(n, c.config)
+    result = searchInScopes(c, ident, amb)
     if result == nil: result = errorUndeclaredIdentifierHint(c, n, ident)
   else:
     internalError(c.config, n.info, "lookUp")
-    return
+    return nil
   if amb:
     #contains(c.ambiguousSymbols, result.id):
     result = errorUseQualifier(c, n.info, result, amb)
@@ -593,14 +614,16 @@ proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
     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)
     else:
-      let candidates = searchInScopesFilterBy(c, ident, allExceptModule) #.skipAlias(n, c.config)
+      let candidates = searchInScopesFilterBy(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)
+      else:
+        result = nil
     if result == nil:
       let candidates = allPureEnumFields(c, ident)
       if candidates.len > 0:
@@ -627,13 +650,20 @@ 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
+            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)
       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, n[1], considerQuotedIdent(c, n[1]))
       elif checkUndeclared in flags and
            n[1].kind notin {nkOpenSymChoice, nkClosedSymChoice}:
         localError(c.config, n[1].info, "identifier expected, but got: " &
@@ -649,11 +679,12 @@ 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 +692,7 @@ 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 +703,7 @@ 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 +716,10 @@ 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 +733,7 @@ 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 +748,12 @@ 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 +761,10 @@ 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 +779,29 @@ 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 +812,28 @@ 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 +842,23 @@ 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

@@ -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)
@@ -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)
@@ -347,7 +330,8 @@ proc genDeref*(n: PNode; k = nkHiddenDeref): PNode =
 
 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:

compiler/magicsys.nim

@@ -26,11 +26,11 @@ 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 = newSym(skError, getIdent(g.cache, name), g.idgen, g.systemModule, g.systemModule.info, {})
     result.typ = newType(tyError, nextTypeId(g.idgen), g.systemModule)
-  if result.kind == skAlias: result = result.owner
 
 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:
@@ -39,7 +39,7 @@ proc getSysMagic*(g: ModuleGraph; info: TLineInfo; name: string, m: TMagic): PSy
       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 = newSym(skError, id, g.idgen, g.systemModule, g.systemModule.info, {})
   result.typ = newType(tyError, nextTypeId(g.idgen), g.systemModule)
 
 proc sysTypeFromName*(g: ModuleGraph; info: TLineInfo; name: string): PType =
@@ -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
 
@@ -100,7 +100,7 @@ proc skipIntLit*(t: PType; id: IdGenerator): PType {.inline.} =
 
 proc addSonSkipIntLit*(father, son: PType; id: IdGenerator) =
   let s = son.skipIntLit(id)
-  father.sons.add(s)
+  father.add(s)
   propagateToOwner(father, s)
 
 proc getCompilerProc*(g: ModuleGraph; name: string): PSym =
@@ -124,7 +124,7 @@ 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
@@ -146,6 +146,7 @@ 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)
 

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,
@@ -22,6 +22,8 @@ import
   modules,
   modulegraphs, lineinfos, pathutils, vmprofiler
 
+# ensure NIR compiles:
+import nir / nir
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions]
@@ -29,6 +31,8 @@ when defined(nimPreviewSlimSystem):
 import ic / [cbackend, integrity, navigator]
 from ic / ic import rodViewer
 
+import ../dist/checksums/src/checksums/sha1
+
 import pipelines
 
 when not defined(leanCompiler):
@@ -54,7 +58,7 @@ 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 +117,7 @@ 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) =
@@ -194,7 +198,7 @@ proc commandScan(cache: IdentCache, config: ConfigRef) =
   if stream != nil:
     var
       L: Lexer
-      tok: Token
+      tok: Token = default(Token)
     initToken(tok)
     openLexer(L, f, stream, cache, config)
     while true:
@@ -265,7 +269,7 @@ 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 backendInvalid: raiseAssert "unreachable"
 
   proc compileToBackend() =
     customizeForBackend(conf.backend)
@@ -275,7 +279,7 @@ proc mainCommand*(graph: ModuleGraph) =
     of backendCpp: commandCompileToC(graph)
     of backendObjc: commandCompileToC(graph)
     of backendJs: commandCompileToJS(graph)
-    of backendInvalid: doAssert false
+    of backendInvalid: raiseAssert "unreachable"
 
   template docLikeCmd(body) =
     when defined(leanCompiler):
@@ -415,7 +419,7 @@ 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/modulegraphs.nim

@@ -11,7 +11,8 @@
 ## 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 intsets, tables, hashes
+import ../dist/checksums/src/checksums/md5
 import ast, astalgo, options, lineinfos,idents, btrees, ropes, msgs, pathutils, packages
 import ic / [packed_ast, ic]
 
@@ -78,6 +79,7 @@ type
     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
+    memberProcsPerType*: Table[ItemId, seq[PSym]] # Type ID, attached member procs (only c++, virtual and ctor so far)
     enumToStringProcs*: Table[ItemId, LazySym]
     emittedTypeInfo*: Table[string, FileIndex]
 
@@ -140,7 +142,7 @@ 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):
@@ -194,8 +196,8 @@ 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)
@@ -366,6 +368,7 @@ 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:
@@ -411,7 +414,7 @@ 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}
 
@@ -456,7 +459,7 @@ 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 = @[]
@@ -466,9 +469,9 @@ proc initModuleGraphFields(result: ModuleGraph) =
   result.suggestSymbols = initTable[FileIndex, seq[SymInfoPair]]()
   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]()
@@ -485,7 +488,7 @@ 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 +496,12 @@ 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
@@ -603,6 +607,7 @@ 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 +615,7 @@ 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 +637,8 @@ 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)

compiler/msgs.nim

@@ -226,7 +226,7 @@ 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 +234,7 @@ 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 +294,11 @@ 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 +410,7 @@ 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)
@@ -502,6 +504,8 @@ 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 +515,8 @@ 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
@@ -576,7 +581,8 @@ 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

compiler/nilcheck.nim

@@ -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:
@@ -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 = ""
@@ -765,7 +766,7 @@ 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
 
@@ -862,9 +863,10 @@ 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)
@@ -909,7 +911,7 @@ 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(
@@ -920,7 +922,7 @@ proc infix(ctx: NilCheckerContext, l: PNode, r: PNode, magic: TMagic): PNode =
 
 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(
@@ -947,7 +949,7 @@ proc checkCase(n, ctx, map): Check =
   let base = n[0]
   result.map = map.copyMap()
   result.nilability = Safe
-  var a: PNode
+  var a: PNode = nil
   for child in n:
     case child.kind:
     of nkOfBranch:
@@ -1222,7 +1224,7 @@ proc check(n: PNode, ctx: NilCheckerContext, map: NilMap): Check =
       # 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:
@@ -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:

compiler/nim.cfg

@@ -7,6 +7,7 @@ define:nimcore
 define:nimPreviewFloatRoundtrip
 define:nimPreviewSlimSystem
 define:nimPreviewCstringConversion
+define:nimPreviewProcConversion
 define:nimPreviewRangeDefault
 threads:off
 
@@ -14,7 +15,6 @@ threads:off
 
 @if windows:
   cincludes: "$lib/wrappers/libffi/common"
-  tlsEmulation:off
 @end
 
 define:useStdoutAsStdmsg
@@ -31,9 +31,6 @@ define:useStdoutAsStdmsg
   warning[ObservableStores]:off
 @end
 
-@if nimHasWarnCastSizes:
-  warning[CastSizes]:on
-@end
 
 @if nimHasWarningAsError:
   warningAsError[GcUnsafe2]:on
@@ -46,3 +43,11 @@ define:useStdoutAsStdmsg
 @if nimHasWarnBareExcept:
   warningAserror[BareExcept]:on
 @end
+
+
+@if nimUseStrictDefs:
+  experimental:strictDefs
+  warningAsError[Uninit]:on
+  warningAsError[ProveInit]:on
+@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".}
@@ -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(
@@ -140,7 +140,7 @@ 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

@@ -10,11 +10,13 @@
 ## Implements some helper procs for Nimble (Nim's package manager) support.
 
 import parseutils, strutils, os, options, msgs, sequtils, lineinfos, pathutils,
-  std/sha1, tables
+  tables
 
 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 +37,16 @@ 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":
@@ -143,7 +150,7 @@ 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

@@ -214,7 +214,7 @@ 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)
@@ -228,6 +228,8 @@ proc readConfigFile*(filename: AbsoluteFile; cache: IdentCache;
     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 +252,7 @@ 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

@@ -12,7 +12,7 @@ import
   ast, modules, condsyms,
   options, llstream, lineinfos, vm,
   vmdef, modulegraphs, idents, os, pathutils,
-  scriptconfig, std/compilesettings
+  scriptconfig, std/[compilesettings, tables]
 
 import pipelines
 
@@ -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/nimsets.nim

@@ -62,7 +62,9 @@ proc someInSet*(s: PNode, a, b: PNode): bool =
   result = false
 
 proc toBitSet*(conf: ConfigRef; s: PNode): TBitSet =
-  var first, j: Int128
+  result = @[]
+  var first: Int128 = Zero
+  var j: Int128 = Zero
   first = firstOrd(conf, s.typ[0])
   bitSetInit(result, int(getSize(conf, s.typ)))
   for i in 0..<s.len:

compiler/nir/cir.nim

@@ -0,0 +1,78 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# We produce C code as a list of tokens.
+
+import std / assertions
+import .. / ic / bitabs
+
+type
+  Token = LitId # indexing into the tokens BiTable[string]
+
+  PredefinedToken = enum
+    IgnoreMe = "<unused>"
+    EmptyToken = ""
+    DeclPrefix = "" # the next token is the name of a definition
+    CurlyLe = "{"
+    CurlyRi = "}"
+    ParLe = "("
+    ParRi = ")"
+    BracketLe = "["
+    BracketRi = "]"
+    NewLine = "\n"
+    Semicolon = ";"
+    Comma = ", "
+    Space = " "
+    Colon = ":"
+    Dot = "."
+    Arrow = "->"
+    Star = "*"
+    Amp = "&"
+    AsgnOpr = " = "
+    ScopeOpr = "::"
+    ConstKeyword = "const "
+    StaticKeyword = "static "
+    NimString = "NimString"
+    StrLitPrefix = "(NimChar*)"
+    StrLitNamePrefix = "Qstr"
+    LoopKeyword = "while (true) "
+    WhileKeyword = "while ("
+    IfKeyword = "if ("
+    ElseKeyword = "else "
+    SwitchKeyword = "switch ("
+    CaseKeyword = "case "
+    DefaultKeyword = "default:"
+    BreakKeyword = "break"
+    NullPtr = "nullptr"
+    IfNot = "if (!("
+    ReturnKeyword = "return "
+
+const
+  ModulePrefix = Token(int(ReturnKeyword)+1)
+
+proc fillTokenTable(tab: var BiTable[string]) =
+  for e in EmptyToken..high(PredefinedToken):
+    let id = tab.getOrIncl $e
+    assert id == LitId(e)
+
+type
+  GeneratedCode* = object
+    code: seq[LitId]
+    tokens: BiTable[string]
+
+proc initGeneratedCode*(): GeneratedCode =
+  result = GeneratedCode(code: @[], tokens: initBiTable[string]())
+  fillTokenTable(result.tokens)
+
+proc add*(g: var GeneratedCode; t: PredefinedToken) {.inline.} =
+  g.code.add Token(t)
+
+proc add*(g: var GeneratedCode; s: string) {.inline.} =
+  g.code.add g.tokens.getOrIncl(s)
+

compiler/nir/nir.nim

@@ -0,0 +1,22 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Nim Intermediate Representation, designed to capture all of Nim's semantics without losing too much
+## precious information. Can easily be translated into C. And to JavaScript, hopefully.
+
+import nirtypes, nirinsts, ast2ir
+
+when false:
+  type
+    Module* = object
+      types: TypeGraph
+      data: seq[Tree]
+      init: seq[Tree]
+      procs: seq[Tree]
+

compiler/nir/nirinsts.nim

@@ -0,0 +1,314 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## NIR instructions. Somewhat inspired by LLVM's instructions.
+
+import std / [assertions, hashes, strformat]
+import .. / ic / bitabs
+import nirlineinfos, nirtypes
+
+type
+  SymId* = distinct int
+
+proc `$`*(s: SymId): string {.borrow.}
+proc hash*(s: SymId): Hash {.borrow.}
+proc `==`*(a, b: SymId): bool {.borrow.}
+
+type
+  Opcode* = enum
+    Nop,
+    ImmediateVal,
+    IntVal,
+    StrVal,
+    SymDef,
+    SymUse,
+    ModuleId,
+    Typed,   # with type ID
+    NilVal,
+    Label,
+    Goto,
+    CheckedGoto,
+    LoopLabel,
+    GotoLoop,  # last atom
+
+    ModuleSymUse, # `module.x`
+
+    ArrayConstr,
+    ObjConstr,
+    Ret,
+    Yld,
+
+    Select,
+    SelectPair,  # ((values...), Label)
+    SelectList,  # (values...)
+    SelectValue, # (value)
+    SelectRange, # (valueA..valueB)
+    SummonGlobal,
+    SummonThreadLocal,
+    Summon, # x = Summon Typed <Type ID>; x begins to live
+    Kill, # `Kill x`: scope end for `x`
+
+    AddrOf,
+    ArrayAt, # addr(a[i])
+    FieldAt, # addr(obj.field)
+
+    Load, # a[]
+    Store, # a[] = b
+    Asgn,  # a = b
+    SetExc,
+    TestExc,
+
+    Call,
+    IndirectCall,
+    CheckedCall, # call that can raise
+    CheckedIndirectCall, # call that can raise
+    CheckedAdd, # with overflow checking etc.
+    CheckedSub,
+    CheckedMul,
+    CheckedDiv,
+    CheckedMod,
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod,
+    BitShl,
+    BitShr,
+    BitAnd,
+    BitOr,
+    BitXor,
+    BitNot,
+    Eq,
+    Le,
+    Lt,
+    Cast,
+    NumberConv,
+    CheckedObjConv,
+    ObjConv,
+    TestOf,
+    Emit,
+    ProcDecl
+
+const
+  LastAtomicValue = GotoLoop
+
+  OpcodeBits = 8'u32
+  OpcodeMask = (1'u32 shl OpcodeBits) - 1'u32
+
+  ValueProducingAtoms = {ImmediateVal, IntVal, StrVal, SymUse, NilVal}
+
+  ValueProducing* = {
+    ImmediateVal,
+    IntVal,
+    StrVal,
+    SymUse,
+    NilVal,
+    ModuleSymUse,
+    ArrayConstr,
+    ObjConstr,
+    CheckedAdd,
+    CheckedSub,
+    CheckedMul,
+    CheckedDiv,
+    CheckedMod,
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod,
+    BitShl,
+    BitShr,
+    BitAnd,
+    BitOr,
+    BitXor,
+    BitNot,
+    Eq,
+    Le,
+    Lt,
+    Cast,
+    NumberConv,
+    CheckedObjConv,
+    ObjConv,
+    AddrOf,
+    Load,
+    ArrayAt,
+    FieldAt,
+    TestOf
+  }
+
+type
+  Instr* = object     # 8 bytes
+    x: uint32
+    info: PackedLineInfo
+
+template kind*(n: Instr): Opcode = Opcode(n.x and OpcodeMask)
+template operand(n: Instr): uint32 = (n.x shr OpcodeBits)
+
+template toX(k: Opcode; operand: uint32): uint32 =
+  uint32(k) or (operand shl OpcodeBits)
+
+template toX(k: Opcode; operand: LitId): uint32 =
+  uint32(k) or (operand.uint32 shl OpcodeBits)
+
+proc `$`*(n: Instr): string =
+  result = fmt"{n.kind}: {n.operand}"
+
+
+type
+  Tree* = object
+    nodes: seq[Instr]
+
+  Values* = object
+    numbers: BiTable[int64]
+    strings: BiTable[string]
+
+type
+  PatchPos* = distinct int
+  NodePos* = distinct int
+
+const
+  InvalidPatchPos* = PatchPos(-1)
+
+proc debug*(t: Tree) {.deprecated.} =
+  for i in t.nodes:
+    echo i
+
+proc isValid(p: PatchPos): bool {.inline.} = p.int != -1
+
+proc prepare*(tree: var Tree; info: PackedLineInfo; kind: Opcode): PatchPos =
+  result = PatchPos tree.nodes.len
+  tree.nodes.add Instr(x: toX(kind, 1'u32), info: info)
+
+proc isAtom(tree: Tree; pos: int): bool {.inline.} = tree.nodes[pos].kind <= LastAtomicValue
+proc isAtom(tree: Tree; pos: NodePos): bool {.inline.} = tree.nodes[pos.int].kind <= LastAtomicValue
+
+proc patch*(tree: var Tree; pos: PatchPos) =
+  let pos = pos.int
+  let k = tree.nodes[pos].kind
+  assert k > LastAtomicValue
+  let distance = int32(tree.nodes.len - pos)
+  assert distance > 0
+  tree.nodes[pos].x = toX(k, cast[uint32](distance))
+
+template build*(tree: var Tree; info: PackedLineInfo; kind: Opcode; body: untyped) =
+  let pos = prepare(tree, info, kind)
+  body
+  patch(tree, pos)
+
+proc len*(tree: Tree): int {.inline.} = tree.nodes.len
+
+template rawSpan(n: Instr): int = int(operand(n))
+
+proc nextChild(tree: Tree; pos: var int) {.inline.} =
+  if tree.nodes[pos].kind > LastAtomicValue:
+    assert tree.nodes[pos].operand > 0'u32
+    inc pos, tree.nodes[pos].rawSpan
+  else:
+    inc pos
+
+iterator sons*(tree: Tree; n: NodePos): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+template `[]`*(t: Tree; n: NodePos): Instr = t.nodes[n.int]
+
+proc span(tree: Tree; pos: int): int {.inline.} =
+  if tree.nodes[pos].kind <= LastAtomicValue: 1 else: int(tree.nodes[pos].operand)
+
+proc copyTree*(dest: var Tree; src: Tree) =
+  let pos = 0
+  let L = span(src, pos)
+  let d = dest.nodes.len
+  dest.nodes.setLen(d + L)
+  assert L > 0
+  for i in 0..<L:
+    dest.nodes[d+i] = src.nodes[pos+i]
+
+type
+  LabelId* = distinct int
+
+proc newLabel*(labelGen: var int): LabelId {.inline.} =
+  result = LabelId labelGen
+  inc labelGen
+
+proc addNewLabel*(t: var Tree; labelGen: var int; info: PackedLineInfo; k: Opcode): LabelId =
+  assert k in {Label, LoopLabel}
+  result = LabelId labelGen
+  t.nodes.add Instr(x: toX(k, uint32(result)), info: info)
+  inc labelGen
+
+proc boolVal*(t: var Tree; info: PackedLineInfo; b: bool) =
+  t.nodes.add Instr(x: toX(ImmediateVal, uint32(b)), info: info)
+
+proc gotoLabel*(t: var Tree; info: PackedLineInfo; k: Opcode; L: LabelId) =
+  assert k in {Goto, GotoLoop, CheckedGoto}
+  t.nodes.add Instr(x: toX(k, uint32(L)), info: info)
+
+proc addLabel*(t: var Tree; info: PackedLineInfo; k: Opcode; L: LabelId) {.inline.} =
+  assert k in {Label, LoopLabel, Goto, GotoLoop, CheckedGoto}
+  t.nodes.add Instr(x: toX(k, uint32(L)), info: info)
+
+proc addSymUse*(t: var Tree; info: PackedLineInfo; s: SymId) {.inline.} =
+  t.nodes.add Instr(x: toX(SymUse, uint32(s)), info: info)
+
+proc addTyped*(t: var Tree; info: PackedLineInfo; typ: TypeId) {.inline.} =
+  t.nodes.add Instr(x: toX(Typed, uint32(typ)), info: info)
+
+proc addSummon*(t: var Tree; info: PackedLineInfo; s: SymId; typ: TypeId) {.inline.} =
+  let x = prepare(t, info, Summon)
+  t.nodes.add Instr(x: toX(SymDef, uint32(s)), info: info)
+  t.nodes.add Instr(x: toX(Typed, uint32(typ)), info: info)
+  patch t, x
+
+proc addImmediateVal*(t: var Tree; info: PackedLineInfo; x: int) =
+  assert x >= 0 and x < ((1 shl 32) - OpcodeBits.int)
+  t.nodes.add Instr(x: toX(ImmediateVal, uint32(x)), info: info)
+
+type
+  Value* = distinct Tree
+
+proc prepare*(dest: var Value; info: PackedLineInfo; k: Opcode): PatchPos {.inline.} =
+  assert k in ValueProducing - ValueProducingAtoms
+  result = prepare(Tree(dest), info, k)
+
+proc patch*(dest: var Value; pos: PatchPos) {.inline.} =
+  patch(Tree(dest), pos)
+
+proc localToValue*(info: PackedLineInfo; s: SymId): Value =
+  result = Value(Tree())
+  Tree(result).addSymUse info, s
+
+proc hasValue*(v: Value): bool {.inline.} = Tree(v).len > 0
+
+proc isEmpty*(v: Value): bool {.inline.} = Tree(v).len == 0
+
+proc extractTemp*(v: Value): SymId =
+  if hasValue(v) and Tree(v)[NodePos 0].kind == SymUse:
+    result = SymId(Tree(v)[NodePos 0].operand)
+  else:
+    result = SymId(-1)
+
+proc copyTree*(dest: var Tree; src: Value) = copyTree dest, Tree(src)
+
+proc addImmediateVal*(t: var Value; info: PackedLineInfo; x: int) =
+  assert x >= 0 and x < ((1 shl 32) - OpcodeBits.int)
+  Tree(t).nodes.add Instr(x: toX(ImmediateVal, uint32(x)), info: info)
+
+template build*(tree: var Value; info: PackedLineInfo; kind: Opcode; body: untyped) =
+  let pos = prepare(Tree(tree), info, kind)
+  body
+  patch(tree, pos)
+
+proc addTyped*(t: var Value; info: PackedLineInfo; typ: TypeId) {.inline.} =
+  addTyped(Tree(t), info, typ)

compiler/nir/nirlineinfos.nim

@@ -0,0 +1,78 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# For the line information we use 32 bits. They are used as follows:
+# Bit 0 (AsideBit): If we have inline line information or not. If not, the
+# remaining 31 bits are used as an index into a seq[(LitId, int, int)].
+#
+# We use 10 bits for the "file ID", this means a program can consist of as much
+# as 1024 different files. (If it uses more files than that, the overflow bit
+# would be set.)
+# This means we have 21 bits left to encode the (line, col) pair. We use 7 bits for the column
+# so 128 is the limit and 14 bits for the line number.
+# The packed representation supports files with up to 16384 lines.
+# Keep in mind that whenever any limit is reached the AsideBit is set and the real line
+# information is kept in a side channel.
+
+import std / assertions
+
+const
+  AsideBit = 1
+  FileBits = 10
+  LineBits = 14
+  ColBits = 7
+  FileMax = (1 shl FileBits) - 1
+  LineMax = (1 shl LineBits) - 1
+  ColMax = (1 shl ColBits) - 1
+
+static:
+  assert AsideBit + FileBits + LineBits + ColBits == 32
+
+import .. / ic / bitabs # for LitId
+
+type
+  PackedLineInfo* = distinct uint32
+
+  LineInfoManager* = object
+    aside*: seq[(LitId, int32, int32)]
+
+proc pack*(m: var LineInfoManager; file: LitId; line, col: int32): PackedLineInfo =
+  if file.uint32 <= FileMax.uint32 and line <= LineMax and col <= ColMax:
+    let col = if col < 0'i32: 0'u32 else: col.uint32
+    let line = if line < 0'i32: 0'u32 else: line.uint32
+    # use inline representation:
+    result = PackedLineInfo((file.uint32 shl 1'u32) or (line shl uint32(AsideBit + FileBits)) or
+      (col shl uint32(AsideBit + FileBits + LineBits)))
+  else:
+    result = PackedLineInfo((m.aside.len shl 1) or AsideBit)
+    m.aside.add (file, line, col)
+
+proc unpack*(m: LineInfoManager; i: PackedLineInfo): (LitId, int32, int32) =
+  let i = i.uint32
+  if (i and 1'u32) == 0'u32:
+    # inline representation:
+    result = (LitId((i shr 1'u32) and FileMax.uint32),
+      int32((i shr uint32(AsideBit + FileBits)) and LineMax.uint32),
+      int32((i shr uint32(AsideBit + FileBits + LineBits)) and ColMax.uint32))
+  else:
+    result = m.aside[int(i shr 1'u32)]
+
+proc getFileId*(m: LineInfoManager; i: PackedLineInfo): LitId =
+  result = unpack(m, i)[0]
+
+when isMainModule:
+  var m = LineInfoManager(aside: @[])
+  for i in 0'i32..<16388'i32:
+    for col in 0'i32..<100'i32:
+      let packed = pack(m, LitId(1023), i, col)
+      let u = unpack(m, packed)
+      assert u[0] == LitId(1023)
+      assert u[1] == i
+      assert u[2] == col
+  echo m.aside.len

compiler/nir/nirslots.nim

@@ -0,0 +1,97 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Management of slots. Similar to "register allocation"
+## in lower level languages.
+
+import std / [assertions, tables]
+import nirtypes, nirinsts
+
+type
+  SlotManagerFlag* = enum
+    ReuseTemps,
+    ReuseVars
+  SlotManager* = object # "register allocator"
+    live: Table[SymId, TypeId]
+    dead: Table[TypeId, seq[SymId]]
+    flags: set[SlotManagerFlag]
+    inScope: seq[SymId]
+    locGen: ref int
+
+proc initSlotManager*(flags: set[SlotManagerFlag]; generator: ref int): SlotManager {.inline.} =
+  SlotManager(flags: flags, locGen: generator)
+
+proc allocRaw(m: var SlotManager; t: TypeId; f: SlotManagerFlag): SymId {.inline.} =
+  if f in m.flags and m.dead.hasKey(t) and m.dead[t].len > 0:
+    result = m.dead[t].pop()
+  else:
+    result = SymId(m.locGen[])
+    inc m.locGen[]
+    m.inScope.add result
+  m.live[result] = t
+
+proc allocTemp*(m: var SlotManager; t: TypeId): SymId {.inline.} =
+  result = allocRaw(m, t, ReuseTemps)
+
+proc allocVar*(m: var SlotManager; t: TypeId): SymId {.inline.} =
+  result = allocRaw(m, t, ReuseVars)
+
+proc freeLoc*(m: var SlotManager; s: SymId) =
+  let t = m.live.getOrDefault(s)
+  assert t.int != 0
+  m.live.del s
+  m.dead.mgetOrPut(t, @[]).add s
+
+iterator stillAlive*(m: SlotManager): (SymId, TypeId) =
+  for k, v in pairs(m.live):
+    yield (k, v)
+
+proc getType*(m: SlotManager; s: SymId): TypeId {.inline.} = m.live[s]
+
+proc openScope*(m: var SlotManager) =
+  m.inScope.add SymId(-1) # add marker
+
+proc closeScope*(m: var SlotManager) =
+  var i = m.inScope.len - 1
+  while i >= 0:
+    if m.inScope[i] == SymId(-1):
+      m.inScope.setLen i-1
+      break
+    dec i
+
+when isMainModule:
+  var m = initSlotManager({ReuseTemps}, new(int))
+
+  var g = initTypeGraph()
+
+  let a = g.openType ArrayTy
+  g.addBuiltinType Int8Id
+  g.addArrayLen 5'u64
+  let finalArrayType = sealType(g, a)
+
+  let obj = g.openType ObjectDecl
+  g.addName "MyType"
+
+  g.addField "p", finalArrayType
+  let objB = sealType(g, obj)
+
+  let x = m.allocTemp(objB)
+  assert x.int == 0
+
+  let y = m.allocTemp(objB)
+  assert y.int == 1
+
+  let z = m.allocTemp(Int8Id)
+  assert z.int == 2
+
+  m.freeLoc y
+  let y2 = m.allocTemp(objB)
+  assert y2.int == 1
+
+

compiler/nir/nirtypes.nim

@@ -0,0 +1,339 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Type system for NIR. Close to C's type system but without its quirks.
+
+import std / [assertions, hashes]
+import .. / ic / bitabs
+
+type
+  NirTypeKind* = enum
+    VoidTy, IntTy, UIntTy, FloatTy, BoolTy, CharTy, NameVal, IntVal,
+    AnnotationVal,
+    VarargsTy, # the `...` in a C prototype; also the last "atom"
+    APtrTy, # pointer to aliasable memory
+    UPtrTy, # pointer to unique/unaliasable memory
+    AArrayPtrTy, # pointer to array of aliasable memory
+    UArrayPtrTy, # pointer to array of unique/unaliasable memory
+    ArrayTy,
+    LastArrayTy, # array of unspecified size as a last field inside an object
+    ObjectTy,
+    UnionTy,
+    ProcTy,
+    ObjectDecl,
+    UnionDecl,
+    FieldDecl
+
+const
+  TypeKindBits = 8'u32
+  TypeKindMask = (1'u32 shl TypeKindBits) - 1'u32
+
+type
+  TypeNode* = object     # 4 bytes
+    x: uint32
+
+template kind*(n: TypeNode): NirTypeKind = NirTypeKind(n.x and TypeKindMask)
+template operand(n: TypeNode): uint32 = (n.x shr TypeKindBits)
+
+template toX(k: NirTypeKind; operand: uint32): uint32 =
+  uint32(k) or (operand shl TypeKindBits)
+
+template toX(k: NirTypeKind; operand: LitId): uint32 =
+  uint32(k) or (operand.uint32 shl TypeKindBits)
+
+type
+  TypeId* = distinct int
+
+proc `==`*(a, b: TypeId): bool {.borrow.}
+proc hash*(a: TypeId): Hash {.borrow.}
+
+type
+  TypeGraph* = object
+    nodes: seq[TypeNode]
+    names: BiTable[string]
+    numbers: BiTable[uint64]
+
+const
+  VoidId* = TypeId 0
+  Bool8Id* = TypeId 1
+  Char8Id* = TypeId 2
+  Int8Id* = TypeId 3
+  Int16Id* = TypeId 4
+  Int32Id* = TypeId 5
+  Int64Id* = TypeId 6
+  UInt8Id* = TypeId 7
+  UInt16Id* = TypeId 8
+  UInt32Id* = TypeId 9
+  UInt64Id* = TypeId 10
+  Float32Id* = TypeId 11
+  Float64Id* = TypeId 12
+  LastBuiltinId* = 12
+
+proc initTypeGraph*(): TypeGraph =
+  result = TypeGraph(nodes: @[
+    TypeNode(x: toX(VoidTy, 0'u32)),
+    TypeNode(x: toX(BoolTy, 8'u32)),
+    TypeNode(x: toX(CharTy, 8'u32)),
+    TypeNode(x: toX(IntTy, 8'u32)),
+    TypeNode(x: toX(IntTy, 16'u32)),
+    TypeNode(x: toX(IntTy, 32'u32)),
+    TypeNode(x: toX(IntTy, 64'u32)),
+    TypeNode(x: toX(UIntTy, 8'u32)),
+    TypeNode(x: toX(UIntTy, 16'u32)),
+    TypeNode(x: toX(UIntTy, 32'u32)),
+    TypeNode(x: toX(UIntTy, 64'u32)),
+    TypeNode(x: toX(FloatTy, 32'u32)),
+    TypeNode(x: toX(FloatTy, 64'u32))
+  ])
+  assert result.nodes.len == LastBuiltinId+1
+
+type
+  TypePatchPos* = distinct int
+
+const
+  InvalidTypePatchPos* = TypePatchPos(-1)
+  LastAtomicValue = VarargsTy
+
+proc isValid(p: TypePatchPos): bool {.inline.} = p.int != -1
+
+proc prepare(tree: var TypeGraph; kind: NirTypeKind): TypePatchPos =
+  result = TypePatchPos tree.nodes.len
+  tree.nodes.add TypeNode(x: toX(kind, 1'u32))
+
+proc isAtom(tree: TypeGraph; pos: int): bool {.inline.} = tree.nodes[pos].kind <= LastAtomicValue
+proc isAtom(tree: TypeGraph; pos: TypeId): bool {.inline.} = tree.nodes[pos.int].kind <= LastAtomicValue
+
+proc patch(tree: var TypeGraph; pos: TypePatchPos) =
+  let pos = pos.int
+  let k = tree.nodes[pos].kind
+  assert k > LastAtomicValue
+  let distance = int32(tree.nodes.len - pos)
+  assert distance > 0
+  tree.nodes[pos].x = toX(k, cast[uint32](distance))
+
+proc len*(tree: TypeGraph): int {.inline.} = tree.nodes.len
+
+template rawSpan(n: TypeNode): int = int(operand(n))
+
+proc nextChild(tree: TypeGraph; pos: var int) {.inline.} =
+  if tree.nodes[pos].kind > LastAtomicValue:
+    assert tree.nodes[pos].operand > 0'u32
+    inc pos, tree.nodes[pos].rawSpan
+  else:
+    inc pos
+
+iterator sons*(tree: TypeGraph; n: TypeId): TypeId =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  while pos < last:
+    yield TypeId pos
+    nextChild tree, pos
+
+template `[]`*(t: TypeGraph; n: TypeId): TypeNode = t.nodes[n.int]
+
+proc elementType*(tree: TypeGraph; n: TypeId): TypeId {.inline.} =
+  assert tree[n].kind in {APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy, ArrayTy, LastArrayTy}
+  result = TypeId(n.int+1)
+
+proc kind*(tree: TypeGraph; n: TypeId): NirTypeKind {.inline.} = tree[n].kind
+
+proc span(tree: TypeGraph; pos: int): int {.inline.} =
+  if tree.nodes[pos].kind <= LastAtomicValue: 1 else: int(tree.nodes[pos].operand)
+
+proc sons2(tree: TypeGraph; n: TypeId): (TypeId, TypeId) =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  result = (TypeId a, TypeId b)
+
+proc sons3(tree: TypeGraph; n: TypeId): (TypeId, TypeId, TypeId) =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  result = (TypeId a, TypeId b, TypeId c)
+
+proc arrayLen*(tree: TypeGraph; n: TypeId): BiggestUInt =
+  assert tree[n].kind == ArrayTy
+  result = tree.numbers[LitId tree[n].operand]
+
+proc openType*(tree: var TypeGraph; kind: NirTypeKind): TypePatchPos =
+  assert kind in {APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy,
+    ArrayTy, LastArrayTy, ProcTy, ObjectDecl, UnionDecl,
+    FieldDecl}
+  result = prepare(tree, kind)
+
+proc sealType*(tree: var TypeGraph; p: TypePatchPos): TypeId =
+  # TODO: Search for an existing instance of this type in
+  # order to reduce memory consumption.
+  result = TypeId(p)
+  patch tree, p
+
+proc nominalType*(tree: var TypeGraph; kind: NirTypeKind; name: string): TypeId =
+  assert kind in {ObjectTy, UnionTy}
+  result = TypeId tree.nodes.len
+  tree.nodes.add TypeNode(x: toX(kind, tree.names.getOrIncl(name)))
+
+proc addNominalType*(tree: var TypeGraph; kind: NirTypeKind; name: string) =
+  assert kind in {ObjectTy, UnionTy}
+  tree.nodes.add TypeNode(x: toX(kind, tree.names.getOrIncl(name)))
+
+proc addVarargs*(tree: var TypeGraph) =
+  tree.nodes.add TypeNode(x: toX(VarargsTy, 0'u32))
+
+proc getFloat128Type*(tree: var TypeGraph): TypeId =
+  result = TypeId tree.nodes.len
+  tree.nodes.add TypeNode(x: toX(FloatTy, 128'u32))
+
+proc addBuiltinType*(g: var TypeGraph; id: TypeId) =
+  g.nodes.add g[id]
+
+template firstSon(n: TypeId): TypeId = TypeId(n.int+1)
+
+proc addType*(g: var TypeGraph; t: TypeId) =
+  # We cannot simply copy `*Decl` nodes. We have to introduce `*Ty` nodes instead:
+  if g[t].kind in {ObjectDecl, UnionDecl}:
+    assert g[t.firstSon].kind == NameVal
+    let name = LitId g[t.firstSon].operand
+    if g[t].kind == ObjectDecl:
+      g.nodes.add TypeNode(x: toX(ObjectTy, name))
+    else:
+      g.nodes.add TypeNode(x: toX(UnionTy, name))
+  else:
+    let pos = t.int
+    let L = span(g, pos)
+    let d = g.nodes.len
+    g.nodes.setLen(d + L)
+    assert L > 0
+    for i in 0..<L:
+      g.nodes[d+i] = g.nodes[pos+i]
+
+proc addArrayLen*(g: var TypeGraph; len: uint64) =
+  g.nodes.add TypeNode(x: toX(IntVal, g.numbers.getOrIncl(len)))
+
+proc addName*(g: var TypeGraph; name: string) =
+  g.nodes.add TypeNode(x: toX(NameVal, g.names.getOrIncl(name)))
+
+proc addAnnotation*(g: var TypeGraph; name: string) =
+  g.nodes.add TypeNode(x: toX(NameVal, g.names.getOrIncl(name)))
+
+proc addField*(g: var TypeGraph; name: string; typ: TypeId) =
+  let f = g.openType FieldDecl
+  g.addType typ
+  g.addName name
+  discard sealType(g, f)
+
+proc toString*(dest: var string; g: TypeGraph; i: TypeId) =
+  case g[i].kind
+  of VoidTy: dest.add "void"
+  of IntTy:
+    dest.add "i"
+    dest.addInt g[i].operand
+  of UIntTy:
+    dest.add "u"
+    dest.addInt g[i].operand
+  of FloatTy:
+    dest.add "f"
+    dest.addInt g[i].operand
+  of BoolTy:
+    dest.add "b"
+    dest.addInt g[i].operand
+  of CharTy:
+    dest.add "c"
+    dest.addInt g[i].operand
+  of NameVal, AnnotationVal:
+    dest.add g.names[LitId g[i].operand]
+  of IntVal:
+    dest.add $g.numbers[LitId g[i].operand]
+  of VarargsTy:
+    dest.add "..."
+  of APtrTy:
+    dest.add "aptr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of UPtrTy:
+    dest.add "uptr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of AArrayPtrTy:
+    dest.add "aArrayPtr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of UArrayPtrTy:
+    dest.add "uArrayPtr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of ArrayTy:
+    dest.add "Array["
+    let (elems, len) = g.sons2(i)
+    toString(dest, g, elems)
+    dest.add ", "
+    toString(dest, g, len)
+    dest.add "]"
+  of LastArrayTy:
+    # array of unspecified size as a last field inside an object
+    dest.add "LastArrayTy["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of ObjectTy:
+    dest.add "object "
+    dest.add g.names[LitId g[i].operand]
+  of UnionTy:
+    dest.add "union "
+    dest.add g.names[LitId g[i].operand]
+  of ProcTy:
+    dest.add "proc["
+    for t in sons(g, i): toString(dest, g, t)
+    dest.add "]"
+  of ObjectDecl:
+    dest.add "object["
+    for t in sons(g, i):
+      toString(dest, g, t)
+      dest.add '\n'
+    dest.add "]"
+  of UnionDecl:
+    dest.add "union["
+    for t in sons(g, i):
+      toString(dest, g, t)
+      dest.add '\n'
+    dest.add "]"
+  of FieldDecl:
+    let (typ, name) = g.sons2(i)
+    toString(dest, g, typ)
+    dest.add ' '
+    toString(dest, g, name)
+
+proc toString*(dest: var string; g: TypeGraph) =
+  var i = 0
+  while i < g.len:
+    toString(dest, g, TypeId i)
+    dest.add '\n'
+    nextChild g, i
+
+proc `$`(g: TypeGraph): string =
+  result = ""
+  toString(result, g)
+
+when isMainModule:
+  var g = initTypeGraph()
+
+  let a = g.openType ArrayTy
+  g.addBuiltinType Int8Id
+  g.addArrayLen 5'u64
+  let finalArrayType = sealType(g, a)
+
+  let obj = g.openType ObjectDecl
+  g.nodes.add TypeNode(x: toX(NameVal, g.names.getOrIncl("MyType")))
+
+  g.addField "p", finalArrayType
+  discard sealType(g, obj)
+
+  echo g

compiler/nir/types2ir.nim

@@ -0,0 +1,426 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+import std / [assertions, tables, sets]
+import ".." / [ast, types, options, sighashes, modulegraphs]
+import nirtypes
+
+type
+  TypesCon* = object
+    processed: Table[ItemId, TypeId]
+    recursionCheck: HashSet[ItemId]
+    g: TypeGraph
+    conf: ConfigRef
+
+proc initTypesCon*(conf: ConfigRef): TypesCon =
+  TypesCon(g: initTypeGraph(), conf: conf)
+
+proc mangle(c: var TypesCon; t: PType): string =
+  result = $sighashes.hashType(t, c.conf)
+
+template cached(c: var TypesCon; t: PType; body: untyped) =
+  result = c.processed.getOrDefault(t.itemId)
+  if result.int == 0:
+    body
+    c.processed[t.itemId] = result
+
+proc typeToIr*(c: var TypesCon; t: PType): TypeId
+
+proc collectFieldTypes(c: var TypesCon; n: PNode; dest: var Table[ItemId, TypeId]) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      collectFieldTypes(c, n[i], dest)
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    collectFieldTypes(c, n[0], dest)
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        collectFieldTypes c, lastSon(n[i]), dest
+      else: discard
+  of nkSym:
+    dest[n.sym.itemId] = typeToIr(c, n.sym.typ)
+  else:
+    assert false, "unknown node kind: " & $n.kind
+
+proc objectToIr(c: var TypesCon; n: PNode; fieldTypes: Table[ItemId, TypeId]; unionId: var int) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      objectToIr(c, n[i], fieldTypes, unionId)
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    objectToIr(c, n[0], fieldTypes, unionId)
+    let u = openType(c.g, UnionDecl)
+    c.g.addName "u_" & $unionId
+    inc unionId
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        let subObj = openType(c.g, ObjectDecl)
+        c.g.addName "uo_" & $unionId & "_" & $i
+        objectToIr c, lastSon(n[i]), fieldTypes, unionId
+        discard sealType(c.g, subObj)
+      else: discard
+    discard sealType(c.g, u)
+  of nkSym:
+    c.g.addField n.sym.name.s & "_" & $n.sym.position, fieldTypes[n.sym.itemId]
+  else:
+    assert false, "unknown node kind: " & $n.kind
+
+proc objectToIr(c: var TypesCon; t: PType): TypeId =
+  if t[0] != nil:
+    # ensure we emitted the base type:
+    discard typeToIr(c, t[0])
+
+  var unionId = 0
+  var fieldTypes = initTable[ItemId, TypeId]()
+  collectFieldTypes c, t.n, fieldTypes
+  let obj = openType(c.g, ObjectDecl)
+  c.g.addName mangle(c, t)
+  if t[0] != nil:
+    c.g.addNominalType(ObjectTy, mangle(c, t[0]))
+  else:
+    c.g.addBuiltinType VoidId # object does not inherit
+    if not lacksMTypeField(t):
+      let f2 = c.g.openType FieldDecl
+      let voidPtr = openType(c.g, APtrTy)
+      c.g.addBuiltinType(VoidId)
+      discard sealType(c.g, voidPtr)
+      c.g.addName "m_type"
+      discard sealType(c.g, f2) # FieldDecl
+
+  objectToIr c, t.n, fieldTypes, unionId
+  result = sealType(c.g, obj)
+
+proc objectHeaderToIr(c: var TypesCon; t: PType): TypeId =
+  result = c.g.nominalType(ObjectTy, mangle(c, t))
+
+proc tupleToIr(c: var TypesCon; t: PType): TypeId =
+  var fieldTypes = newSeq[TypeId](t.len)
+  for i in 0..<t.len:
+    fieldTypes[i] = typeToIr(c, t[i])
+  let obj = openType(c.g, ObjectDecl)
+  c.g.addName mangle(c, t)
+  for i in 0..<t.len:
+    c.g.addField "f_" & $i, fieldTypes[i]
+  result = sealType(c.g, obj)
+
+proc procToIr(c: var TypesCon; t: PType; addEnv = false): TypeId =
+  var fieldTypes = newSeq[TypeId](0)
+  for i in 0..<t.len:
+    if not isCompileTimeOnly(t[i]):
+      fieldTypes.add typeToIr(c, t[i])
+  let obj = openType(c.g, ProcTy)
+
+  case t.callConv
+  of ccNimCall, ccFastCall, ccClosure: c.g.addAnnotation "__fastcall"
+  of ccStdCall: c.g.addAnnotation "__stdcall"
+  of ccCDecl: c.g.addAnnotation "__cdecl"
+  of ccSafeCall: c.g.addAnnotation "__safecall"
+  of ccSysCall: c.g.addAnnotation "__syscall"
+  of ccInline: c.g.addAnnotation "__inline"
+  of ccNoInline: c.g.addAnnotation "__noinline"
+  of ccThisCall: c.g.addAnnotation "__thiscall"
+  of ccNoConvention: c.g.addAnnotation ""
+
+  for i in 0..<fieldTypes.len:
+    c.g.addType fieldTypes[i]
+
+  if addEnv:
+    let a = openType(c.g, APtrTy)
+    c.g.addBuiltinType(VoidId)
+    discard sealType(c.g, a)
+
+  if tfVarargs in t.flags:
+    c.g.addVarargs()
+  result = sealType(c.g, obj)
+
+proc nativeInt(c: TypesCon): TypeId =
+  case c.conf.target.intSize
+  of 2: result = Int16Id
+  of 4: result = Int32Id
+  else: result = Int64Id
+
+proc openArrayToIr(c: var TypesCon; t: PType): TypeId =
+  # object (a: ArrayPtr[T], len: int)
+  let e = lastSon(t)
+  let mangledBase = mangle(c, e)
+  let typeName = "NimOpenArray" & mangledBase
+
+  let elementType = typeToIr(c, e)
+
+  let p = openType(c.g, ObjectDecl)
+  c.g.addName typeName
+
+  let f = c.g.openType FieldDecl
+  let arr = c.g.openType AArrayPtrTy
+  c.g.addType elementType
+  discard sealType(c.g, arr) # LastArrayTy
+  c.g.addName "data"
+  discard sealType(c.g, f) # FieldDecl
+
+  c.g.addField "len", c.nativeInt
+
+  result = sealType(c.g, p) # ObjectDecl
+
+
+proc stringToIr(c: var TypesCon; t: PType): TypeId =
+  #[
+
+    NimStrPayload = object
+      cap: int
+      data: UncheckedArray[char]
+
+    NimStringV2 = object
+      len: int
+      p: ptr NimStrPayload
+
+  ]#
+  let p = openType(c.g, ObjectDecl)
+  c.g.addName "NimStrPayload"
+  c.g.addField "cap", c.nativeInt
+
+  let f = c.g.openType FieldDecl
+  let arr = c.g.openType LastArrayTy
+  c.g.addBuiltinType Char8Id
+  discard sealType(c.g, arr) # LastArrayTy
+  c.g.addName "data"
+  discard sealType(c.g, f) # FieldDecl
+
+  let payload = sealType(c.g, p)
+
+  let str = openType(c.g, ObjectDecl)
+  c.g.addName "NimStringV2"
+  c.g.addField "len", c.nativeInt
+
+  let fp = c.g.openType FieldDecl
+  let ffp = c.g.openType APtrTy
+  c.g.addNominalType ObjectTy, "NimStrPayload"
+  discard sealType(c.g, ffp) # APtrTy
+  c.g.addName "p"
+  discard sealType(c.g, fp) # FieldDecl
+
+  result = sealType(c.g, str) # ObjectDecl
+
+proc seqToIr(c: var TypesCon; t: PType): TypeId =
+  #[
+    NimSeqPayload[T] = object
+      cap: int
+      data: UncheckedArray[T]
+
+    NimSeqV2*[T] = object
+      len: int
+      p: ptr NimSeqPayload[T]
+
+  ]#
+  let e = lastSon(t)
+  let mangledBase = mangle(c, e)
+  let payloadName = "NimSeqPayload" & mangledBase
+
+  let elementType = typeToIr(c, e)
+
+  let p = openType(c.g, ObjectDecl)
+  c.g.addName payloadName
+  c.g.addField "cap", c.nativeInt
+
+  let f = c.g.openType FieldDecl
+  let arr = c.g.openType LastArrayTy
+  c.g.addType elementType
+  discard sealType(c.g, arr) # LastArrayTy
+  c.g.addName "data"
+  discard sealType(c.g, f) # FieldDecl
+
+  let payload = sealType(c.g, p)
+
+  let sq = openType(c.g, ObjectDecl)
+  c.g.addName "NimSeqV2" & mangledBase
+  c.g.addField "len", c.nativeInt
+
+  let fp = c.g.openType FieldDecl
+  let ffp = c.g.openType APtrTy
+  c.g.addNominalType ObjectTy, "NimSeqPayload" & mangledBase
+  discard sealType(c.g, ffp) # APtrTy
+  c.g.addName "p"
+  discard sealType(c.g, fp) # FieldDecl
+
+  result = sealType(c.g, sq) # ObjectDecl
+
+
+proc closureToIr(c: var TypesCon; t: PType): TypeId =
+  # struct {fn(args, void* env), env}
+  # typedef struct {$n" &
+  #        "N_NIMCALL_PTR($2, ClP_0) $3;$n" &
+  #        "void* ClE_0;$n} $1;$n"
+  let mangledBase = mangle(c, t)
+  let typeName = "NimClosure" & mangledBase
+
+  let procType = procToIr(c, t, addEnv=true)
+
+  let p = openType(c.g, ObjectDecl)
+  c.g.addName typeName
+
+  let f = c.g.openType FieldDecl
+  c.g.addType procType
+  c.g.addName "ClP_0"
+  discard sealType(c.g, f) # FieldDecl
+
+  let f2 = c.g.openType FieldDecl
+  let voidPtr = openType(c.g, APtrTy)
+  c.g.addBuiltinType(VoidId)
+  discard sealType(c.g, voidPtr)
+
+  c.g.addName "ClE_0"
+  discard sealType(c.g, f2) # FieldDecl
+
+  result = sealType(c.g, p) # ObjectDecl
+
+proc typeToIr*(c: var TypesCon; t: PType): TypeId =
+  case t.kind
+  of tyInt:
+    case int(getSize(c.conf, t))
+    of 2: result = Int16Id
+    of 4: result = Int32Id
+    else: result = Int64Id
+  of tyInt8: result = Int8Id
+  of tyInt16: result = Int16Id
+  of tyInt32: result = Int32Id
+  of tyInt64: result = Int64Id
+  of tyFloat:
+    case int(getSize(c.conf, t))
+    of 4: result = Float32Id
+    else: result = Float64Id
+  of tyFloat32: result = Float32Id
+  of tyFloat64: result = Float64Id
+  of tyFloat128: result = getFloat128Type(c.g)
+  of tyUInt:
+    case int(getSize(c.conf, t))
+    of 2: result = UInt16Id
+    of 4: result = UInt32Id
+    else: result = UInt64Id
+  of tyUInt8: result = UInt8Id
+  of tyUInt16: result = UInt16Id
+  of tyUInt32: result = UInt32Id
+  of tyUInt64: result = UInt64Id
+  of tyBool: result = Bool8Id
+  of tyChar: result = Char8Id
+  of tyVoid: result = VoidId
+  of tySink, tyGenericInst, tyDistinct, tyAlias, tyOwned, tyRange:
+    result = typeToIr(c, t.lastSon)
+  of tyEnum:
+    if firstOrd(c.conf, t) < 0:
+      result = Int32Id
+    else:
+      case int(getSize(c.conf, t))
+      of 1: result = UInt8Id
+      of 2: result = UInt16Id
+      of 4: result = Int32Id
+      of 8: result = Int64Id
+      else: result = Int32Id
+  of tyOrdinal, tyGenericBody, tyGenericParam, tyInferred, tyStatic:
+    if t.len > 0:
+      result = typeToIr(c, t.lastSon)
+    else:
+      result = TypeId(-1)
+  of tyFromExpr:
+    if t.n != nil and t.n.typ != nil:
+      result = typeToIr(c, t.n.typ)
+    else:
+      result = TypeId(-1)
+  of tyArray:
+    cached(c, t):
+      var n = toInt64(lengthOrd(c.conf, t))
+      if n <= 0: n = 1   # make an array of at least one element
+      let elemType = typeToIr(c, t[1])
+      let a = openType(c.g, ArrayTy)
+      c.g.addType(elemType)
+      c.g.addArrayLen uint64(n)
+      result = sealType(c.g, a)
+  of tyPtr, tyRef:
+    cached(c, t):
+      let e = t.lastSon
+      if e.kind == tyUncheckedArray:
+        let elemType = typeToIr(c, e.lastSon)
+        let a = openType(c.g, AArrayPtrTy)
+        c.g.addType(elemType)
+        result = sealType(c.g, a)
+      else:
+        let elemType = typeToIr(c, t.lastSon)
+        let a = openType(c.g, APtrTy)
+        c.g.addType(elemType)
+        result = sealType(c.g, a)
+  of tyVar, tyLent:
+    cached(c, t):
+      let elemType = typeToIr(c, t.lastSon)
+      let a = openType(c.g, APtrTy)
+      c.g.addType(elemType)
+      result = sealType(c.g, a)
+  of tySet:
+    let s = int(getSize(c.conf, t))
+    case s
+    of 1: result = UInt8Id
+    of 2: result = UInt16Id
+    of 4: result = UInt32Id
+    of 8: result = UInt64Id
+    else:
+      # array[U8, s]
+      cached(c, t):
+        let a = openType(c.g, ArrayTy)
+        c.g.addType(UInt8Id)
+        c.g.addArrayLen uint64(s)
+        result = sealType(c.g, a)
+  of tyPointer:
+    let a = openType(c.g, APtrTy)
+    c.g.addBuiltinType(VoidId)
+    result = sealType(c.g, a)
+  of tyObject:
+    # Objects are special as they can be recursive in Nim. This is easily solvable.
+    # We check if we are already "processing" t. If so, we produce `ObjectTy`
+    # instead of `ObjectDecl`.
+    cached(c, t):
+      if not c.recursionCheck.containsOrIncl(t.itemId):
+        result = objectToIr(c, t)
+      else:
+        result = objectHeaderToIr(c, t)
+  of tyTuple:
+    cached(c, t):
+      result = tupleToIr(c, t)
+  of tyProc:
+    cached(c, t):
+      if t.callConv == ccClosure:
+        result = closureToIr(c, t)
+      else:
+        result = procToIr(c, t)
+  of tyVarargs, tyOpenArray:
+    cached(c, t):
+      result = openArrayToIr(c, t)
+  of tyString:
+    cached(c, t):
+      result = stringToIr(c, t)
+  of tySequence:
+    cached(c, t):
+      result = seqToIr(c, t)
+  of tyCstring:
+    cached(c, t):
+      let a = openType(c.g, AArrayPtrTy)
+      c.g.addBuiltinType Char8Id
+      result = sealType(c.g, a)
+  of tyUncheckedArray:
+    # We already handled the `ptr UncheckedArray` in a special way.
+    cached(c, t):
+      let elemType = typeToIr(c, t.lastSon)
+      let a = openType(c.g, LastArrayTy)
+      c.g.addType(elemType)
+      result = sealType(c.g, a)
+  of tyNone, tyEmpty, tyUntyped, tyTyped, tyTypeDesc,
+     tyNil, tyGenericInvocation, tyProxy, tyBuiltInTypeClass,
+     tyUserTypeClass, tyUserTypeClassInst, tyCompositeTypeClass,
+     tyAnd, tyOr, tyNot, tyAnything, tyConcept, tyIterable, tyForward:
+    result = TypeId(-1)

compiler/nir/utils.nim

@@ -0,0 +1,2 @@
+template unreachable*(s = "unreachable") = raiseAssert s
+template todo*(s = "todo") = raiseAssert s

compiler/nversion.nim

@@ -12,6 +12,8 @@
 
 const
   MaxSetElements* = 1 shl 16  # (2^16) to support unicode character sets?
+  DefaultSetElements* = 1 shl 8
+    ## assumed set element count when using int literals
   VersionAsString* = system.NimVersion
   RodFileVersion* = "1223"       # modify this if the rod-format changes!
 

compiler/optimizer.nim

@@ -113,7 +113,7 @@ proc analyse(c: var Con; b: var BasicBlock; n: PNode) =
     if n[0].kind == nkSym:
       let s = n[0].sym
       let name = s.name.s.normalize
-      if s.magic == mWasMoved or name == "=wasmoved":
+      if name == "=wasmoved":
         b.wasMovedLocs.add n
         special = true
       elif name == "=destroy":
@@ -279,7 +279,7 @@ proc optimize*(n: PNode): PNode =
 
     Now assume 'use' raises, then we shouldn't do the 'wasMoved(s)'
   ]#
-  var c: Con
+  var c: Con = Con()
   var b: BasicBlock
   analyse(c, b, n)
   if c.somethingTodo: