switch on

Currently pragmas just fall through to `suggestSentinel` and show
everything which isn't very useful. Now it filters for symbols that
could be pragmas (templates with `{.pragma.}`, macros, user pragmas) and
only shows them

.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/workflows/bisects.yml

@@ -5,19 +5,27 @@ on:
     types: created
 
 jobs:
-  test:
-    runs-on: ubuntu-latest
+  bisects:
+    if: |
+      github.event_name == 'issue_comment' && startsWith(github.event.comment.body, '!nim ') && github.event.issue.pull_request == null && github.event.comment.author_association != 'NONE'
+    strategy:
+      fail-fast: false
+      matrix:
+        platform: [ubuntu-latest, windows-latest, macos-latest]
+    name: ${{ matrix.platform }}-bisects
+    runs-on: ${{ matrix.platform }}
     steps:
-    - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
-    # nimrun-action requires Nim installed.
-    - uses: jiro4989/setup-nim-action@v1
-      with:
-        nim-version: 'devel'
+      - 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 }}
+      - uses: juancarlospaco/nimrun-action@nim
+        if: |
+          runner.os == 'Linux'   && contains(github.event.comment.body, '-d:linux'  ) ||
+          runner.os == 'Windows' && contains(github.event.comment.body, '-d:windows') ||
+          runner.os == 'macOS'   && contains(github.event.comment.body, '-d:osx'    ) ||
+          runner.os == 'Linux' && !contains(github.event.comment.body, '-d:linux') && !contains(github.event.comment.body, '-d:windows') && !contains(github.event.comment.body, '-d:osx')
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/ci_bench.yml

@@ -17,14 +17,14 @@ jobs:
     timeout-minutes: 60 # refs bug #18178
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 2
 
-      - name: 'Install node.js 16.x'
-        uses: actions/setup-node@v3
+      - name: 'Install node.js 20.x'
+        uses: actions/setup-node@v4
         with:
-          node-version: '16.x'
+          node-version: '20.x'
 
       - name: 'Install dependencies (Linux amd64)'
         if: runner.os == 'Linux' && matrix.cpu == 'amd64'
@@ -60,7 +60,7 @@ jobs:
         run: nim c -r -d:release ci/action.nim
 
       - name: 'Checkout minimize'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: 'nim-lang/ci_bench'
           path: minimize

.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

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

.github/workflows/ci_publish.yml

@@ -17,14 +17,14 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 2
 
-      - name: 'Install node.js 16.x'
-        uses: actions/setup-node@v3
+      - name: 'Install node.js 20.x'
+        uses: actions/setup-node@v4
         with:
-          node-version: '16.x'
+          node-version: '20.x'
 
       - name: 'Install dependencies (Linux amd64)'
         if: runner.os == 'Linux' && matrix.cpu == 'amd64'

azure-pipelines.yml

@@ -73,8 +73,8 @@ jobs:
 
     - task: NodeTool@0
       inputs:
-        versionSpec: '16.x'
-      displayName: 'Install node.js 16.x'
+        versionSpec: '20.x'
+      displayName: 'Install node.js 20.x'
       condition: and(succeeded(), eq(variables['skipci'], 'false'))
 
     - bash: |

changelog.md

@@ -3,28 +3,46 @@
 
 ## Changes affecting backward compatibility
 
+- `-d:nimStrictDelete` becomes the default. An index error is produced when the index passed to `system.delete` was out of bounds. Use `-d:nimAuditDelete` to mimic the old behavior for backwards compatibility.
+- The default user-agent in `std/httpclient` has been changed to `Nim-httpclient/<version>` instead of `Nim httpclient/<version>` which was incorrect according to the HTTP spec.
+- Methods now support implementations based on a VTable by using `--experimental:vtables`. Methods are then confined to be in the same module where their type has been defined.
+- With `-d:nimPreviewNonVarDestructor`, non-var destructors become the default.
 
 ## Standard library additions and changes
 
 [//]: # "Changes:"
 
+- Changed `std/osfiles.copyFile` to allow to specify `bufferSize` instead of a hardcoded one.
+- Changed `std/osfiles.copyFile` to use `POSIX_FADV_SEQUENTIAL` hints for kernel-level aggressive sequential read-aheads.
+- `std/htmlparser` has been moved to a nimble package, use `nimble` or `atlas` to install it.
 
 [//]: # "Additions:"
 
+- Added `newStringUninit` to system, which creates a new string of length `len` like `newString` but with uninitialized content.
+- Added `setLenUninit` to system, which doesn't initalize
+slots when enlarging a sequence.
+- Added `hasDefaultValue` to `std/typetraits` to check if a type has a valid default value.
+- Added Viewport API for the JavaScript targets in the `dom` module.
+
 [//]: # "Deprecations:"
 
+- Deprecates `system.newSeqUninitialized`, which is replaced by `newSeqUninit`.
 
 [//]: # "Removals:"
 
 
 ## Language changes
 
-
+- `noInit` can be used in types and fields to disable member initializers in the C++ backend. 
+- C++ custom constructors initializers see https://nim-lang.org/docs/manual_experimental.htm#constructor-initializer
+- `member` can be used to attach a procedure to a C++ type.
+- C++ `constructor` now reuses `result` instead creating `this`.
 
 ## Compiler changes
 
-
-
+- `--nimcache` using a relative path as the argument in a config file is now relative to the config file instead of the current directory.
 
 ## Tool changes
 
+- koch now allows bootstrapping with `-d:nimHasLibFFI`, replacing the older option of building the compiler directly w/ the `libffi` nimble package in tow.
+

changelogs/changelog_2_0_0_details.md

@@ -205,7 +205,7 @@
   proc prc(): int =
     123
 
-  iterator iter(): int =
+  iterator iter(): int {.closure.} =
     yield 123
 
   proc takesProc[T: proc](x: T) = discard

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)
 

compiler/aliasanalysis.nim

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

compiler/aliases.nim

@@ -10,7 +10,9 @@
 ## Simple alias analysis for the HLO and the code generators.
 
 import
-  ast, astalgo, types, trees, intsets
+  ast, astalgo, types, trees
+
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -114,6 +116,8 @@ 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 +153,7 @@ 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 +169,7 @@ 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 +191,9 @@ 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 +211,6 @@ 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

@@ -10,8 +10,10 @@
 # abstract syntax tree + symbol table
 
 import
-  lineinfos, hashes, options, ropes, idents, int128, tables
-from strutils import toLowerAscii
+  lineinfos, options, ropes, idents, int128, wordrecg
+
+import std/[tables, hashes]
+from std/strutils import toLowerAscii
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -314,6 +316,7 @@ type
                       # 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]
@@ -347,6 +350,7 @@ const
   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
@@ -589,6 +593,7 @@ type
     tfEffectSystemWorkaround
     tfIsOutParam
     tfSendable
+    tfImplicitStatic
 
   TTypeFlags* = set[TTypeFlag]
 
@@ -638,7 +643,7 @@ const
   skError* = skUnknown
 
 var
-  eqTypeFlags* = {tfIterator, tfNotNil, tfVarIsPtr, tfGcSafe, tfNoSideEffect, tfIsOutParam, tfSendable}
+  eqTypeFlags* = {tfIterator, tfNotNil, tfVarIsPtr, tfGcSafe, tfNoSideEffect, tfIsOutParam}
     ## type flags that are essential for type equality.
     ## This is now a variable because for emulation of version:1.0 we
     ## might exclude {tfGcSafe, tfNoSideEffect}.
@@ -898,6 +903,7 @@ type
     info*: TLineInfo
     when defined(nimsuggest):
       endInfo*: TLineInfo
+      hasUserSpecifiedType*: bool  # used for determining whether to display inlay type hints
     owner*: PSym
     flags*: TSymFlags
     ast*: PNode               # syntax tree of proc, iterator, etc.:
@@ -921,7 +927,7 @@ type
                               # for variables a slot index for the evaluator
     offset*: int32            # offset of record field
     disamb*: int32            # disambiguation number; the basic idea is that
-                              # `<procname>__<module>_<disamb>`
+                              # `<procname>__<module>_<disamb>` is unique
     loc*: TLoc
     annex*: PLib              # additional fields (seldom used, so we use a
                               # reference to another object to save space)
@@ -933,6 +939,7 @@ type
                               # 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]
 
@@ -955,7 +962,7 @@ 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
@@ -1036,6 +1043,8 @@ 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
@@ -1157,7 +1166,7 @@ proc idGeneratorFromModule*(m: PSym): IdGenerator =
 proc idGeneratorForPackage*(nextIdWillBe: int32): IdGenerator =
   result = IdGenerator(module: PackageModuleId, symId: nextIdWillBe - 1'i32, typeId: 0, disambTable: initCountTable[PIdent]())
 
-proc nextSymId*(x: IdGenerator): ItemId {.inline.} =
+proc nextSymId(x: IdGenerator): ItemId {.inline.} =
   assert(not x.sealed)
   inc x.symId
   result = ItemId(module: x.module, item: x.symId)
@@ -1222,6 +1231,7 @@ 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
@@ -1241,6 +1251,8 @@ 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
@@ -1256,6 +1268,12 @@ 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 =
@@ -1485,7 +1503,7 @@ 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
 
@@ -1523,15 +1541,31 @@ 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, idgen: IdGenerator; owner: PSym, sons: seq[PType] = @[]): PType =
+  let id = nextTypeId idgen
   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: IdGenerator; owner: PSym, parent: PType): PType =
+  newType(kind, id, owner, parent.sons)
+
+proc setSons*(dest: PType; sons: seq[PType]) {.inline.} = dest.sons = sons
+
+when false:
+  proc newType*(prev: PType, sons: seq[PType]): PType =
+    result = prev
+    result.sons = sons
 
 proc mergeLoc(a: var TLoc, b: TLoc) =
   if a.k == low(typeof(a.k)): a.k = b.k
@@ -1561,13 +1595,17 @@ proc assignType*(dest, src: PType) =
   newSons(dest, src.len)
   for i in 0..<src.len: dest[i] = src[i]
 
-proc copyType*(t: PType, id: ItemId, owner: PSym): PType =
-  result = newType(t.kind, id, owner)
+proc copyType*(t: PType, idgen: IdGenerator, owner: PSym): PType =
+  result = newType(t.kind, idgen, owner)
   assignType(result, t)
   result.sym = t.sym          # backend-info should not be copied
 
 proc exactReplica*(t: PType): PType =
-  result = copyType(t, t.itemId, t.owner)
+  result = PType(kind: t.kind, owner: t.owner, size: defaultSize,
+                 align: defaultAlignment, itemId: t.itemId,
+                 uniqueId: t.uniqueId)
+  assignType(result, t)
+  result.sym = t.sym          # backend-info should not be copied
 
 proc copySym*(s: PSym; idgen: IdGenerator): PSym =
   result = newSym(s.kind, s.name, idgen, s.owner, s.info, s.options)
@@ -1597,19 +1635,13 @@ proc createModuleAlias*(s: PSym, idgen: IdGenerator, newIdent: PIdent, info: TLi
   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
@@ -1617,17 +1649,17 @@ 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
@@ -1677,9 +1709,6 @@ proc rawAddSon*(father, son: PType; propagateHasAsgn = true) =
   father.sons.add(son)
   if not son.isNil: propagateToOwner(father, son, propagateHasAsgn)
 
-proc rawAddSonNoPropagationOfTypeFlags*(father, son: PType) =
-  father.sons.add(son)
-
 proc addSonNilAllowed*(father, son: PNode) =
   father.sons.add(son)
 
@@ -1811,6 +1840,7 @@ 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
@@ -1911,7 +1941,7 @@ 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
@@ -1963,7 +1993,7 @@ proc toVar*(typ: PType; kind: TTypeKind; idgen: IdGenerator): PType =
   ## returned. Otherwise ``typ`` is simply returned as-is.
   result = typ
   if typ.kind != kind:
-    result = newType(kind, nextTypeId(idgen), typ.owner)
+    result = newType(kind, idgen, typ.owner)
     rawAddSon(result, typ)
 
 proc toRef*(typ: PType; idgen: IdGenerator): PType =
@@ -1971,7 +2001,7 @@ proc toRef*(typ: PType; idgen: IdGenerator): PType =
   ## returned. Otherwise ``typ`` is simply returned as-is.
   result = typ
   if typ.skipTypes({tyAlias, tyGenericInst}).kind == tyObject:
-    result = newType(tyRef, nextTypeId(idgen), typ.owner)
+    result = newType(tyRef, idgen, typ.owner)
     rawAddSon(result, typ)
 
 proc toObject*(typ: PType): PType =
@@ -2012,9 +2042,11 @@ 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"
+  return n.kind == nkInfix and n[0].kind == nkIdent and n[0].ident.id == ord(wAs)
 
 proc skipColon*(n: PNode): PNode =
   result = n
@@ -2022,10 +2054,12 @@ 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
@@ -2063,14 +2097,20 @@ 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)
 
 proc isSinkType*(t: PType): bool {.inline.} =
   t.kind == tySink or tfHasOwned in t.flags
 
-proc newProcType*(info: TLineInfo; id: ItemId; owner: PSym): PType =
-  result = newType(tyProc, id, owner)
+proc newProcType*(info: TLineInfo; idgen: IdGenerator; owner: PSym): PType =
+  result = newType(tyProc, idgen, owner)
   result.n = newNodeI(nkFormalParams, info)
   rawAddSon(result, nil) # return type
   # result.n[0] used to be `nkType`, but now it's `nkEffectList` because
@@ -2121,7 +2161,7 @@ proc toHumanStr*(kind: TTypeKind): string =
   ## strips leading `tk`
   result = toHumanStrImpl(kind, 2)
 
-proc skipAddr*(n: PNode): PNode {.inline.} =
+proc skipHiddenAddr*(n: PNode): PNode {.inline.} =
   (if n.kind == nkHiddenAddr: n[0] else: n)
 
 proc isNewStyleConcept*(n: PNode): bool {.inline.} =
@@ -2137,3 +2177,7 @@ 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

@@ -12,10 +12,11 @@
 # the data structures here are used in various places of the compiler.
 
 import
-  ast, hashes, intsets, options, lineinfos, ropes, idents, rodutils,
+  ast, options, lineinfos, ropes, idents, rodutils,
   msgs
 
-import strutils except addf
+import std/[hashes, intsets]
+import std/strutils except addf
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -109,7 +110,7 @@ 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 +198,7 @@ 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 +228,11 @@ 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 +330,10 @@ 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:
@@ -365,7 +370,7 @@ proc treeToYamlAux(conf: ConfigRef; n: PNode, marker: var IntSet, indent: int,
       if conf != nil:
         result.addf(",$N$1\"info\": $2", [istr, lineInfoToStr(conf, n.info)])
       case n.kind
-      of nkCharLit..nkInt64Lit:
+      of nkCharLit..nkUInt64Lit:
         result.addf(",$N$1\"intVal\": $2", [istr, rope(n.intVal)])
       of nkFloatLit, nkFloat32Lit, nkFloat64Lit:
         result.addf(",$N$1\"floatVal\": $2",
@@ -404,7 +409,7 @@ proc symToYaml(conf: ConfigRef; n: PSym, indent: int = 0, maxRecDepth: int = - 1
   var marker = initIntSet()
   result = symToYamlAux(conf, n, marker, indent, maxRecDepth)
 
-import tables
+import std/tables
 
 const backrefStyle = "\e[90m"
 const enumStyle = "\e[34m"
@@ -1063,6 +1068,7 @@ 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 +87,11 @@ const populationCount: array[uint8, uint8] = block:
     arr
 
 proc bitSetCard*(x: TBitSet): BiggestInt =
+  result = 0
   for it in x:
     result.inc int(populationCount[it])
+
+proc bitSetToWord*(s: TBitSet; size: int): BiggestUInt =
+  result = 0
+  for j in 0..<size:
+    if j < s.len: result = result or (BiggestUInt(s[j]) shl (j * 8))

compiler/btrees.nim

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

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)
@@ -198,13 +194,14 @@ proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareF
       linefmt(p, cpsStmts, "#nimPrepareStrMutationV2($1);$n", [byRefLoc(p, a)])
     if atyp.kind in {tyVar} and not compileToCpp(p.module):
       result = ("(($5) ? (($4*)(*$1)$3+($2)) : NIM_NIL)" %
-                  [rdLoc(a), rdLoc(b), dataField(p), dest, dataFieldAccessor(p, "*" & rdLoc(a))],
+                  [rdLoc(a), rdLoc(b), dataField(p, ty.kind == tyString), dest, dataFieldAccessor(p, "*" & rdLoc(a))],
                 lengthExpr)
     else:
       result = ("(($5) ? (($4*)$1$3+($2)) : NIM_NIL)" %
-                  [rdLoc(a), rdLoc(b), dataField(p), dest, dataFieldAccessor(p, rdLoc(a))],
+                  [rdLoc(a), rdLoc(b), dataField(p, ty.kind == tyString), dest, dataFieldAccessor(p, rdLoc(a))],
                 lengthExpr)
   else:
+    result = ("", "")
     internalError(p.config, "openArrayLoc: " & typeToString(a.t))
 
 proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
@@ -224,9 +221,9 @@ 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)
-    case skipTypes(a.t, abstractVar+{tyStatic}).kind
+    var a = initLocExpr(p, if n.kind == nkHiddenStdConv: n[1] else: n)
+    let typKind = skipTypes(a.t, abstractVar+{tyStatic}).kind
+    case typKind
     of tyOpenArray, tyVarargs:
       if reifiedOpenArray(n):
         if a.t.kind in {tyVar, tyLent}:
@@ -244,11 +241,11 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
         var t: TLoc
         t.r = "(*$1)" % [a.rdLoc]
         result.add "($4) ? ((*$1)$3) : NIM_NIL, $2" %
-                     [a.rdLoc, lenExpr(p, t), dataField(p),
+                     [a.rdLoc, lenExpr(p, t, typKind == tyString), dataField(p, typKind == tyString),
                       dataFieldAccessor(p, "*" & a.rdLoc)]
       else:
         result.add "($4) ? ($1$3) : NIM_NIL, $2" %
-                     [a.rdLoc, lenExpr(p, a), dataField(p), dataFieldAccessor(p, a.rdLoc)]
+                     [a.rdLoc, lenExpr(p, a, typKind == tyString), dataField(p, typKind == tyString), dataFieldAccessor(p, a.rdLoc)]
     of tyArray:
       result.add "$1, $2" % [rdLoc(a), rope(lengthOrd(p.config, a.t))]
     of tyPtr, tyRef:
@@ -257,7 +254,7 @@ proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
         var t: TLoc
         t.r = "(*$1)" % [a.rdLoc]
         result.add "($4) ? ((*$1)$3) : NIM_NIL, $2" %
-                     [a.rdLoc, lenExpr(p, t), dataField(p),
+                     [a.rdLoc, lenExpr(p, t, typKind == tyString), dataField(p, typKind == tyString),
                       dataFieldAccessor(p, "*" & a.rdLoc)]
       of tyArray:
         result.add "$1, $2" % [rdLoc(a), rope(lengthOrd(p.config, lastSon(a.t)))]
@@ -271,18 +268,17 @@ proc withTmpIfNeeded(p: BProc, a: TLoc, needsTmp: bool): TLoc =
   # Also don't regress for non ARC-builds, too risky.
   if needsTmp and a.lode.typ != nil and p.config.selectedGC in {gcArc, gcAtomicArc, gcOrc} and
       getSize(p.config, a.lode.typ) < 1024:
-    getTemp(p, a.lode.typ, result, needsInit=false)
+    result = getTemp(p, a.lode.typ, needsInit=false)
     genAssignment(p, result, a, {})
   else:
     result = a
 
 proc literalsNeedsTmp(p: BProc, a: TLoc): TLoc =
-  getTemp(p, a.lode.typ, result, needsInit=false)
+  result = getTemp(p, a.lode.typ, needsInit=false)
   genAssignment(p, result, a, {})
 
 proc genArgStringToCString(p: BProc, n: PNode; result: var Rope; needsTmp: bool) {.inline.} =
-  var a: TLoc
-  initLocExpr(p, n[0], a)
+  var a = initLocExpr(p, n[0])
   appcg(p.module, result, "#nimToCStringConv($1)", [withTmpIfNeeded(p, a, needsTmp).rdLoc])
 
 proc genArg(p: BProc, n: PNode, param: PSym; call: PNode; result: var Rope; needsTmp = false) =
@@ -292,16 +288,16 @@ 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]) and 
+  elif ccgIntroducedPtr(p.config, param, call[0].typ[0]) and
     (optByRef notin param.options or not p.module.compileToCpp):
-    initLocExpr(p, n, a)
+    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]
@@ -312,7 +308,7 @@ 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
 
@@ -321,12 +317,13 @@ 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
@@ -382,13 +379,13 @@ 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]:
@@ -420,9 +417,8 @@ 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 = initLocExpr(p, ri[0])
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInstOwned)
   assert(typ.kind == tyProc)
@@ -444,8 +440,7 @@ 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 = initLocExpr(p, ri[0])
 
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInstOwned)
@@ -470,7 +465,7 @@ 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)"
@@ -478,17 +473,15 @@ 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:
@@ -496,11 +489,9 @@ 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:
@@ -668,7 +659,7 @@ 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")
@@ -682,8 +673,7 @@ 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 = initLocExpr(p, ri[0])
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
   assert(typ.kind == tyProc)
@@ -705,10 +695,9 @@ 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:
@@ -728,8 +717,7 @@ 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 = initLocExpr(p, ri[0])
   var pl = "["
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
@@ -771,24 +759,22 @@ 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/ccgliterals.nim

@@ -94,6 +94,48 @@ proc genStringLiteralV2Const(m: BModule; n: PNode; isConst: bool; result: var Ro
     pureLit = m.tmpBase & rope(id)
   result.addf "{$1, (NimStrPayload*)&$2}", [rope(n.strVal.len), pureLit]
 
+# ------ Version 3: destructor based strings and seqs -----------------------
+# strings are enhanced by interned strings
+
+proc toConstLenV3(len: int): string =
+  result = rope((len shl 1) or 1)
+
+proc genStringLiteralDataOnlyV3(m: BModule, s: string; result: Rope; isConst: bool) =
+  # TODO: fixme: perhaps use makeCString for clarity for C
+  m.s[cfsStrData].addf("static $4 NIM_CHAR $1[$2] = $3;$n",
+       [result, rope(s.len), makeCCharArray(s),
+       rope(if isConst: "const" else: "")])
+
+proc genStringLiteralV3(m: BModule; n: PNode; isConst: bool; result: var Rope) =
+  let id = nodeTableTestOrSet(m.dataCache, n, m.labels)
+  if id == m.labels:
+    let pureLit = getTempName(m)
+    genStringLiteralDataOnlyV3(m, n.strVal, pureLit, isConst)
+    let tmp = getTempName(m)
+    result.add tmp
+    cgsym(m, "NimStringV3")
+    # string literal not found in the cache:
+    m.s[cfsStrData].addf("static $4 NimStringV3 $1 = {$2, (NIM_CHAR*)&$3};$n",
+          [tmp, toConstLenV3(n.strVal.len), pureLit, rope(if isConst: "const" else: "")])
+  else:
+    let tmp = getTempName(m)
+    result.add tmp
+    m.s[cfsStrData].addf("static $4 NimStringV3 $1 = {$2, (NIM_CHAR*)&$3};$n",
+          [tmp, toConstLenV3(n.strVal.len), m.tmpBase & rope(id),
+          rope(if isConst: "const" else: "")])
+
+proc genStringLiteralV3Const(m: BModule; n: PNode; isConst: bool; result: var Rope) =
+  let id = nodeTableTestOrSet(m.dataCache, n, m.labels)
+  var pureLit: Rope
+  if id == m.labels:
+    pureLit = getTempName(m)
+    cgsym(m, "NimStringV3")
+    # string literal not found in the cache:
+    genStringLiteralDataOnlyV3(m, n.strVal, pureLit, isConst)
+  else:
+    pureLit = m.tmpBase & rope(id)
+  result.addf "{$1, (NIM_CHAR*)&$2}", [toConstLenV3(n.strVal.len), pureLit]
+
 # ------ Version selector ---------------------------------------------------
 
 proc genStringLiteralDataOnly(m: BModule; s: string; info: TLineInfo;
@@ -104,6 +146,10 @@ proc genStringLiteralDataOnly(m: BModule; s: string; info: TLineInfo;
     let tmp = getTempName(m)
     genStringLiteralDataOnlyV2(m, s, tmp, isConst)
     result.add tmp
+  of 3:
+    let tmp = getTempName(m)
+    genStringLiteralDataOnlyV3(m, s, tmp, isConst)
+    result.add tmp
   else:
     localError(m.config, info, "cannot determine how to produce code for string literal")
 
@@ -114,5 +160,6 @@ proc genStringLiteral(m: BModule; n: PNode; result: var Rope) =
   case detectStrVersion(m)
   of 0, 1: genStringLiteralV1(m, n, result)
   of 2: genStringLiteralV2(m, n, isConst = true, result)
+  of 3: genStringLiteralV3(m, n, isConst = true, result)
   else:
     localError(m.config, n.info, "cannot determine how to produce code for string literal")

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

@@ -50,6 +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
 
@@ -71,7 +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:
@@ -83,7 +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)
@@ -95,7 +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]
@@ -108,7 +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:
@@ -169,7 +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:
@@ -244,8 +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", [])
@@ -264,13 +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)]
 
@@ -290,14 +289,22 @@ proc potentialValueInit(p: BProc; v: PSym; value: PNode; result: var Rope) =
     #echo "New code produced for ", v.name.s, " ", p.config $ value.info
     genBracedInit(p, value, isConst = false, v.typ, result)
 
-proc genCppVarForCtor(p: BProc, v: PSym; vn, value: PNode; decl: var Rope) =
-  var params = newRopeAppender()
+proc genCppParamsForCtor(p: BProc; call: PNode): string = 
+  result = ""
   var argsCounter = 0
-  let typ = skipTypes(value[0].typ, abstractInst)
+  let typ = skipTypes(call[0].typ, abstractInst)
   assert(typ.kind == tyProc)
-  for i in 1..<value.len:
+  for i in 1..<call.len:
     assert(typ.len == typ.n.len)
-    genOtherArg(p, value, i, typ, params, argsCounter)
+    #if it's a type we can just generate here another initializer as we are in an initializer context
+    if call[i].kind == nkCall and call[i][0].kind == nkSym and call[i][0].sym.kind == skType:
+      if argsCounter > 0: result.add ","
+      result.add genCppInitializer(p.module, p, call[i][0].sym.typ)
+    else:
+      genOtherArg(p, call, i, typ, result, argsCounter)
+
+proc genCppVarForCtor(p: BProc; call: PNode; decl: var Rope) =
+  let params = genCppParamsForCtor(p, call)
   if params.len == 0:
     decl = runtimeFormat("$#;\n", [decl])
   else:
@@ -341,7 +348,7 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
       # Only do this for complex types that may need a call to `objectInit`
       if sfThread in v.flags and emulatedThreadVars(p.config) and
         isComplexValueType(v.typ):
-        initLocExprSingleUse(p.module.preInitProc, vn, loc)
+        loc = initLocExprSingleUse(p.module.preInitProc, vn)
       genObjectInit(p.module.preInitProc, cpsInit, v.typ, loc, constructObj)
     # Alternative construction using default constructor (which may zeromem):
     # if sfImportc notin v.flags: constructLoc(p.module.preInitProc, v.loc)
@@ -359,10 +366,10 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
       var decl = localVarDecl(p, vn)
       var tmp: TLoc
       if isCppCtorCall:
-        genCppVarForCtor(p, v, vn, value, decl)
+        genCppVarForCtor(p, value, decl)
         line(p, cpsStmts, decl)
       else:
-        initLocExprSingleUse(p, value, tmp)
+        tmp = initLocExprSingleUse(p, value)
         lineF(p, cpsStmts, "$# = $#;\n", [decl, tmp.rdLoc])
       return
     assignLocalVar(p, vn)
@@ -408,8 +415,7 @@ 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)
@@ -444,7 +450,7 @@ 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:
@@ -452,7 +458,7 @@ 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",
@@ -520,7 +526,7 @@ 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:
@@ -554,8 +560,7 @@ 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])
 
@@ -593,8 +598,7 @@ 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)
 
@@ -622,7 +626,7 @@ 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))
@@ -641,7 +645,7 @@ 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)
@@ -661,14 +665,13 @@ 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 == 4 or call.len == 5)
-    initLocExpr(p, call[1], rangeA)
-    initLocExpr(p, call[2], rangeB)
+    var rangeA = initLocExpr(p, call[1])
+    var rangeB = initLocExpr(p, call[2])
 
     # $n at the beginning because of #9710
     if call.len == 4: # procName(a, b, annotation)
@@ -685,8 +688,7 @@ proc genParForStmt(p: BProc, t: PNode) =
                     rangeA.rdLoc, rangeB.rdLoc,
                     call[3].getStr.rope])
     else: # `||`(a, b, step, annotation)
-      var step: TLoc
-      initLocExpr(p, call[3], step)
+      var step: TLoc = initLocExpr(p, call[3])
       lineF(p, cpsStmts, "$n#pragma omp $5$n" &
                     "for ($1 = $2; $1 <= $3; $1 += $4)",
                     [forLoopVar.loc.rdLoc,
@@ -756,8 +758,7 @@ 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)
@@ -787,12 +788,12 @@ 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,
@@ -834,8 +835,7 @@ 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)
 
@@ -845,8 +845,8 @@ 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))
@@ -869,8 +869,7 @@ 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)
@@ -906,6 +905,7 @@ 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
@@ -913,6 +913,7 @@ 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)
@@ -948,8 +949,7 @@ 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",
@@ -971,15 +971,18 @@ proc genOrdinalCase(p: BProc, n: PNode, d: var TLoc) =
         hasDefault = true
       exprBlock(p, branch.lastSon, d)
       lineF(p, cpsStmts, "break;$n", [])
-    if (hasAssume in CC[p.config.cCompiler].props) and not hasDefault:
-      lineF(p, cpsStmts, "default: __assume(0);$n", [])
+    if not hasDefault:
+      if hasBuiltinUnreachable in CC[p.config.cCompiler].props:
+        lineF(p, cpsStmts, "default: __builtin_unreachable();$n", [])
+      elif hasAssume in CC[p.config.cCompiler].props:
+        lineF(p, cpsStmts, "default: __assume(0);$n", [])
     lineF(p, cpsStmts, "}$n", [])
   if lend != "": fixLabel(p, lend)
 
 proc genCase(p: BProc, t: PNode, d: var TLoc) =
   genLineDir(p, t)
   if not isEmptyType(t.typ) and d.k == locNone:
-    getTemp(p, t.typ, d)
+    d = getTemp(p, t.typ)
   case skipTypes(t[0].typ, abstractVarRange).kind
   of tyString:
     genStringCase(p, t, tyString, d)
@@ -1030,7 +1033,7 @@ 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)
@@ -1195,7 +1198,7 @@ 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
@@ -1273,7 +1276,7 @@ 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)
 
@@ -1380,7 +1383,7 @@ 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:
@@ -1389,7 +1392,7 @@ 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])
@@ -1454,7 +1457,8 @@ 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, $2)", [memberName, checkFor])
@@ -1492,8 +1496,7 @@ proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
     of nkSym:
       var sym = it.sym
       if sym.kind in {skProc, skFunc, skIterator, skMethod}:
-        var a: TLoc
-        initLocExpr(p, it, a)
+        var a: TLoc = initLocExpr(p, it)
         res.add($rdLoc(a))
       elif sym.kind == skType:
         res.add($getTypeDesc(p.module, sym.typ))
@@ -1505,8 +1508,7 @@ proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
       res.add($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:
@@ -1608,11 +1610,10 @@ 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
@@ -1630,9 +1631,8 @@ proc genAsgn(p: BProc, e: PNode, fastAsgn: bool) =
   else:
     let le = e[0]
     let ri = e[1]
-    var a: TLoc
+    var a: TLoc = initLoc(locNone, le, OnUnknown)
     discard getTypeDesc(p.module, le.typ.skipTypes(skipPtrs), dkVar)
-    initLoc(a, locNone, le, OnUnknown)
     a.flags.incl(lfEnforceDeref)
     a.flags.incl(lfPrepareForMutation)
     genLineDir(p, le) # it can be a nkBracketExpr, which may raise
@@ -1644,7 +1644,7 @@ 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/ccgtypes.nim

@@ -11,8 +11,9 @@
 
 # ------------------------- Name Mangling --------------------------------
 
-import sighashes, modulegraphs, strscans
+import sighashes, modulegraphs, std/strscans
 import ../dist/checksums/src/checksums/md5
+import std/sequtils
 
 type
   TypeDescKind = enum
@@ -24,7 +25,7 @@ type
     dkResult #skResult
     dkConst #skConst
     dkOther #skType, skTemp, skLet and skForVar so far
-   
+
 proc descKindFromSymKind(kind: TSymKind): TypeDescKind =
   case kind
   of skParam: dkParam
@@ -33,7 +34,7 @@ proc descKindFromSymKind(kind: TSymKind): TypeDescKind =
   of skResult: dkResult
   of skConst: dkConst
   else: dkOther
- 
+
 proc isKeyword(w: PIdent): bool =
   # Nim and C++ share some keywords
   # it's more efficient to test the whole Nim keywords range
@@ -206,8 +207,12 @@ proc mapType(conf: ConfigRef; typ: PType; isParam: bool): TCTypeKind =
     result = TCTypeKind(ord(typ.kind) - ord(tyInt) + ord(ctInt))
   of tyStatic:
     if typ.n != nil: result = mapType(conf, lastSon typ, isParam)
-    else: doAssert(false, "mapType: " & $typ.kind)
-  else: doAssert(false, "mapType: " & $typ.kind)
+    else:
+      result = ctVoid
+      doAssert(false, "mapType: " & $typ.kind)
+  else:
+    result = ctVoid
+    doAssert(false, "mapType: " & $typ.kind)
 
 
 proc mapReturnType(conf: ConfigRef; typ: PType): TCTypeKind =
@@ -306,6 +311,9 @@ proc getSimpleTypeDesc(m: BModule; typ: PType): Rope =
     result = typeNameOrLiteral(m, typ, "void*")
   of tyString:
     case detectStrVersion(m)
+    of 3:
+      cgsym(m, "NimStringV3")
+      result = typeNameOrLiteral(m, typ, "NimStringV3")
     of 2:
       cgsym(m, "NimStrPayload")
       cgsym(m, "NimStringV2")
@@ -322,7 +330,9 @@ proc getSimpleTypeDesc(m: BModule; typ: PType): Rope =
   of tyDistinct, tyRange, tyOrdinal: result = getSimpleTypeDesc(m, typ[0])
   of tyStatic:
     if typ.n != nil: result = getSimpleTypeDesc(m, lastSon typ)
-    else: internalError(m.config, "tyStatic for getSimpleTypeDesc")
+    else:
+      result = ""
+      internalError(m.config, "tyStatic for getSimpleTypeDesc")
   of tyGenericInst, tyAlias, tySink, tyOwned:
     result = getSimpleTypeDesc(m, lastSon typ)
   else: result = ""
@@ -458,7 +468,7 @@ proc multiFormat*(frmt: var string, chars : static openArray[char], args: openAr
     var num = 0
     while i < frmt.len:
       if frmt[i] == c:
-        inc(i)                  
+        inc(i)
         case frmt[i]
         of c:
           res.add(c)
@@ -471,11 +481,11 @@ proc multiFormat*(frmt: var string, chars : static openArray[char], args: openAr
             if i >= frmt.len or frmt[i] notin {'0'..'9'}: break
           num = j
           if j > high(arg) + 1:
-            doAssert false, "invalid format string: " & frmt
+            raiseAssert "invalid format string: " & frmt
           else:
             res.add(arg[j-1])
         else:
-          doAssert false, "invalid format string: " & frmt
+          raiseAssert "invalid format string: " & frmt
       var start = i
       while i < frmt.len:
         if frmt[i] != c: inc(i)
@@ -487,12 +497,12 @@ proc multiFormat*(frmt: var string, chars : static openArray[char], args: openAr
 template cgDeclFrmt*(s: PSym): string =
   s.constraint.strVal
 
-proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, params: var string,
+proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, name, params: var string,
                    check: var IntSet, declareEnvironment=true;
                    weakDep=false;) =
   let t = prc.typ
   let isCtor = sfConstructor in prc.flags
-  if isCtor:
+  if isCtor or (name[0] == '~' and sfMember in prc.flags): #destructors cant have void
     rettype = ""
   elif t[0] == nil or isInvalidReturnType(m.config, t):
     rettype = "void"
@@ -501,8 +511,8 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, params: var
       rettype = getTypeDescAux(m, t[0], check, dkResult)
     else:
       rettype = runtimeFormat(rettype.replace("'0", "$1"), [getTypeDescAux(m, t[0], check, dkResult)])
-  var types, names, args: seq[string]
-  if not isCtor:    
+  var types, names, args: seq[string] = @[]
+  if not isCtor:
     var this = t.n[1].sym
     fillParamName(m, this)
     fillLoc(this.loc, locParam, t.n[1],
@@ -515,7 +525,7 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, params: var
     types.add getTypeDescWeak(m, this.typ, check, dkParam)
 
   let firstParam = if isCtor: 1 else: 2
-  for i in firstParam..<t.n.len: 
+  for i in firstParam..<t.n.len:
     if t.n[i].kind != nkSym: internalError(m.config, t.n.info, "genMemberProcParams")
     var param = t.n[i].sym
     var descKind = dkParam
@@ -549,6 +559,7 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, params: var
 
   multiFormat(params, @['\'', '#'], [types, names])
   multiFormat(superCall, @['\'', '#'], [types, names])
+  multiFormat(name, @['\'', '#'], [types, names]) #so we can ~'1 on members
   if params == "()":
     if types.len == 0:
       params = "(void)"
@@ -642,6 +653,28 @@ proc mangleRecFieldName(m: BModule; field: PSym): Rope =
     result = rope(mangleField(m, field.name))
   if result == "": internalError(m.config, field.info, "mangleRecFieldName")
 
+proc hasCppCtor(m: BModule; typ: PType): bool =
+  result = false
+  if m.compileToCpp and typ != nil and typ.itemId in m.g.graph.memberProcsPerType:
+    for prc in m.g.graph.memberProcsPerType[typ.itemId]:
+      if sfConstructor in prc.flags:
+        return true
+
+proc genCppParamsForCtor(p: BProc; call: PNode): string
+
+proc genCppInitializer(m: BModule, prc: BProc; typ: PType): string =
+  #To avoid creating a BProc per test when called inside a struct nil BProc is allowed
+  result = "{}"
+  if typ.itemId in m.g.graph.initializersPerType:
+    let call = m.g.graph.initializersPerType[typ.itemId]
+    if call != nil:
+      var p = prc
+      if p == nil:
+        p = BProc(module: m)
+      result = "{" & genCppParamsForCtor(p, call) & "}"
+      if prc == nil:
+        assert p.blocks.len == 0, "BProc belongs to a struct doesnt have blocks"
+
 proc genRecordFieldsAux(m: BModule; n: PNode,
                         rectype: PType,
                         check: var IntSet; result: var Rope; unionPrefix = "") =
@@ -706,8 +739,10 @@ proc genRecordFieldsAux(m: BModule; n: PNode,
       else:
         # don't use fieldType here because we need the
         # tyGenericInst for C++ template support
-        if fieldType.isOrHasImportedCppType():
-          result.addf("\t$1$3 $2{};$n", [getTypeDescAux(m, field.loc.t, check, dkField), sname, noAlias])
+        let noInit = sfNoInit in field.flags or (field.typ.sym != nil and sfNoInit in field.typ.sym.flags)
+        if not noInit and (fieldType.isOrHasImportedCppType() or hasCppCtor(m, field.owner.typ)):
+          var initializer = genCppInitializer(m, nil, fieldType)
+          result.addf("\t$1$3 $2$4;$n", [getTypeDescAux(m, field.loc.t, check, dkField), sname, noAlias, initializer])
         else:
           result.addf("\t$1$3 $2;$n", [getTypeDescAux(m, field.loc.t, check, dkField), sname, noAlias])
   else: internalError(m.config, n.info, "genRecordFieldsAux()")
@@ -719,19 +754,20 @@ proc getRecordFields(m: BModule; typ: PType, check: var IntSet): Rope =
   genRecordFieldsAux(m, typ.n, typ, check, result)
   if typ.itemId in m.g.graph.memberProcsPerType:
     let procs = m.g.graph.memberProcsPerType[typ.itemId]
-    var isDefaultCtorGen, isCtorGen: bool
+    var isDefaultCtorGen, isCtorGen: bool = false
     for prc in procs:
-      var header: Rope
+      var header: Rope = ""
       if sfConstructor in prc.flags:
         isCtorGen = true
         if prc.typ.n.len == 1:
           isDefaultCtorGen = true
+      if lfNoDecl in prc.loc.flags: continue
       genMemberProcHeader(m, prc, header, false, true)
       result.addf "$1;$n", [header]
     if isCtorGen and not isDefaultCtorGen:
       var ch: IntSet
       result.addf "$1() = default;$n", [getTypeDescAux(m, typ, ch, dkOther)]
-    
+
 proc fillObjectFields*(m: BModule; typ: PType) =
   # sometimes generic objects are not consistently merged. We patch over
   # this fact here.
@@ -739,9 +775,10 @@ proc fillObjectFields*(m: BModule; typ: PType) =
   discard getRecordFields(m, typ, check)
 
 proc mangleDynLibProc(sym: PSym): Rope
-  
+
 proc getRecordDescAux(m: BModule; typ: PType, name, baseType: Rope,
-                   check: var IntSet, hasField:var bool): Rope =                 
+                   check: var IntSet, hasField:var bool): Rope =
+  result = ""
   if typ.kind == tyObject:
     if typ[0] == nil:
       if lacksMTypeField(typ):
@@ -782,8 +819,8 @@ proc getRecordDesc(m: BModule; typ: PType, name: Rope,
         structOrUnion = "#pragma pack(push, 1)\L" & structOrUnion(typ)
   else:
     structOrUnion = structOrUnion(typ)
-  var baseType: string 
-  if typ[0] != nil: 
+  var baseType: string = ""
+  if typ[0] != nil:
     baseType = getTypeDescAux(m, typ[0].skipTypes(skipPtrs), check, dkField)
   if typ.sym == nil or sfCodegenDecl notin typ.sym.flags:
     result = structOrUnion & " " & name
@@ -839,7 +876,7 @@ proc resolveStarsInCppType(typ: PType, idx, stars: int): PType =
   # Make sure the index refers to one of the generic params of the type.
   # XXX: we should catch this earlier and report it as a semantic error.
   if idx >= typ.len:
-    doAssert false, "invalid apostrophe type parameter index"
+    raiseAssert "invalid apostrophe type parameter index"
 
   result = typ[idx]
   for i in 1..stars:
@@ -873,6 +910,7 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
   if t != origTyp and origTyp.sym != nil: useHeader(m, origTyp.sym)
   let sig = hashType(origTyp, m.config)
 
+  result = "" # todo move `result = getTypePre(m, t, sig)` here ?
   defer: # defer is the simplest in this case
     if isImportedType(t) and not m.typeABICache.containsOrIncl(sig):
       addAbiCheck(m, t, result)
@@ -953,7 +991,7 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
   of tyProc:
     result = getTypeName(m, origTyp, sig)
     m.typeCache[sig] = result
-    var rettype, desc: Rope
+    var rettype, desc: Rope = ""
     genProcParams(m, t, rettype, desc, check, true, true)
     if not isImportedType(t):
       if t.callConv != ccClosure: # procedure vars may need a closure!
@@ -1030,7 +1068,7 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
       while i < cppName.len:
         if cppName[i] == '\'':
           var chunkEnd = i-1
-          var idx, stars: int
+          var idx, stars: int = 0
           if scanCppGenericSlot(cppName, i, idx, stars):
             result.add cppName.substr(chunkStart, chunkEnd)
             chunkStart = i
@@ -1094,8 +1132,8 @@ proc getTypeDescAux(m: BModule; origTyp: PType, check: var IntSet; kind: TypeDes
     result = ""
   # fixes bug #145:
   excl(check, t.id)
-  
-  
+
+
 proc getTypeDesc(m: BModule; typ: PType; kind = dkParam): Rope =
   var check = initIntSet()
   result = getTypeDescAux(m, typ, check, kind)
@@ -1110,7 +1148,7 @@ proc getClosureType(m: BModule; t: PType, kind: TClosureTypeKind): Rope =
   assert t.kind == tyProc
   var check = initIntSet()
   result = getTempName(m)
-  var rettype, desc: Rope
+  var rettype, desc: Rope = ""
   genProcParams(m, t, rettype, desc, check, declareEnvironment=kind != clHalf)
   if not isImportedType(t):
     if t.callConv != ccClosure or kind != clFull:
@@ -1140,11 +1178,19 @@ proc isReloadable(m: BModule; prc: PSym): bool =
 proc isNonReloadable(m: BModule; prc: PSym): bool =
   return m.hcrOn and sfNonReloadable in prc.flags
 
-proc parseVFunctionDecl(val: string; name, params, retType, superCall: var string; isFnConst, isOverride: var bool; isCtor: bool) =
-  var afterParams: string
+proc parseVFunctionDecl(val: string; name, params, retType, superCall: var string; isFnConst, isOverride, isMemberVirtual: var bool; isCtor: bool, isFunctor=false) =
+  var afterParams: string = ""
   if scanf(val, "$*($*)$s$*", name, params, afterParams):
+    if name.strip() == "operator" and params == "": #isFunctor?
+      parseVFunctionDecl(afterParams, name, params, retType, superCall, isFnConst, isOverride, isMemberVirtual, isCtor, true)
+      return
     isFnConst = afterParams.find("const") > -1
     isOverride = afterParams.find("override") > -1
+    isMemberVirtual = name.find("virtual ") > -1
+    if isMemberVirtual:
+      name = name.replace("virtual ", "")
+    if isFunctor:
+      name = "operator ()"
     if isCtor:
       discard scanf(afterParams, ":$s$*", superCall)
     else:
@@ -1153,28 +1199,28 @@ proc parseVFunctionDecl(val: string; name, params, retType, superCall: var strin
   params = "(" & params & ")"
 
 proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool = false, isFwdDecl : bool = false) =
-  assert {sfVirtual, sfConstructor} * prc.flags != {}
+  assert sfCppMember * prc.flags != {}
   let isCtor = sfConstructor in prc.flags
-  let isVirtual = not isCtor
   var check = initIntSet()
   fillBackendName(m, prc)
   fillLoc(prc.loc, locProc, prc.ast[namePos], OnUnknown)
   var memberOp = "#." #only virtual
   var typ: PType
   if isCtor:
-    typ = prc.typ.sons[0]
+    typ = prc.typ[0]
   else:
-    typ = prc.typ.sons[1]
+    typ = prc.typ[1]
   if typ.kind == tyPtr:
     typ = typ[0]
     memberOp = "#->"
   var typDesc = getTypeDescWeak(m, typ, check, dkParam)
   let asPtrStr = rope(if asPtr: "_PTR" else: "")
-  var name, params, rettype, superCall: string
-  var isFnConst, isOverride: bool
-  parseVFunctionDecl(prc.constraint.strVal, name, params, rettype, superCall, isFnConst, isOverride, isCtor)
-  genMemberProcParams(m, prc, superCall, rettype, params, check, true, false) 
-  var fnConst, override: string
+  var name, params, rettype, superCall: string = ""
+  var isFnConst, isOverride, isMemberVirtual: bool = false
+  parseVFunctionDecl(prc.constraint.strVal, name, params, rettype, superCall, isFnConst, isOverride, isMemberVirtual, isCtor)
+  genMemberProcParams(m, prc, superCall, rettype, name, params, check, true, false)
+  let isVirtual = sfVirtual in prc.flags or isMemberVirtual
+  var fnConst, override: string = ""
   if isCtor:
     name = typDesc
   if isFnConst:
@@ -1182,28 +1228,28 @@ proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool =
   if isFwdDecl:
     if isVirtual:
       rettype = "virtual " & rettype
-      if isOverride: 
+      if isOverride:
         override = " override"
     superCall = ""
   else:
-    if isVirtual:
+    if not isCtor:
       prc.loc.r = "$1$2(@)" % [memberOp, name]
     elif superCall != "":
       superCall = " : " & superCall
-    
+
     name = "$1::$2" % [typDesc, name]
 
   result.add "N_LIB_PRIVATE "
   result.addf("$1$2($3, $4)$5$6$7$8",
         [rope(CallingConvToStr[prc.typ.callConv]), asPtrStr, rettype, name,
         params, fnConst, override, superCall])
-  
+
 proc genProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool = false) =
   # using static is needed for inline procs
   var check = initIntSet()
   fillBackendName(m, prc)
   fillLoc(prc.loc, locProc, prc.ast[namePos], OnUnknown)
-  var rettype, params: Rope
+  var rettype, params: Rope = ""
   genProcParams(m, prc.typ, rettype, params, check, true, false)
   # handle the 2 options for hotcodereloading codegen - function pointer
   # (instead of forward declaration) or header for function body with "_actual" postfix
@@ -1443,7 +1489,7 @@ proc genEnumInfo(m: BModule; typ: PType, name: Rope; info: TLineInfo) =
   genTypeInfoAux(m, typ, typ, name, info)
   var nodePtrs = getTempName(m) & "_" & $typ.n.len
   genTNimNodeArray(m, nodePtrs, rope(typ.n.len))
-  var enumNames, specialCases: Rope
+  var enumNames, specialCases: Rope = ""
   var firstNimNode = m.typeNodes
   var hasHoles = false
   for i in 0..<typ.n.len:
@@ -1488,9 +1534,9 @@ proc genArrayInfo(m: BModule; typ: PType, name: Rope; info: TLineInfo) =
 
 proc fakeClosureType(m: BModule; owner: PSym): PType =
   # we generate the same RTTI as for a tuple[pointer, ref tuple[]]
-  result = newType(tyTuple, nextTypeId m.idgen, owner)
-  result.rawAddSon(newType(tyPointer, nextTypeId m.idgen, owner))
-  var r = newType(tyRef, nextTypeId m.idgen, owner)
+  result = newType(tyTuple, m.idgen, owner)
+  result.rawAddSon(newType(tyPointer, m.idgen, owner))
+  var r = newType(tyRef, m.idgen, owner)
   let obj = createObj(m.g.graph, m.idgen, owner, owner.info, final=false)
   r.rawAddSon(obj)
   result.rawAddSon(r)
@@ -1522,6 +1568,7 @@ proc genTypeInfo2Name(m: BModule; t: PType): Rope =
       result = it.sym.name.s
     else:
       var p = m.owner
+      result = ""
       if p != nil and p.kind == skPackage:
         result.add p.name.s & "."
       result.add m.name.s & "."
@@ -1532,10 +1579,6 @@ proc genTypeInfo2Name(m: BModule; t: PType): Rope =
 
 proc isTrivialProc(g: ModuleGraph; s: PSym): bool {.inline.} = getBody(g, s).len == 0
 
-proc makePtrType(baseType: PType; idgen: IdGenerator): PType =
-  result = newType(tyPtr, nextTypeId idgen, baseType.owner)
-  addSonSkipIntLit(result, baseType, idgen)
-
 proc generateRttiDestructor(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp;
               info: TLineInfo; idgen: IdGenerator; theProc: PSym): PSym =
   # the wrapper is roughly like:
@@ -1547,7 +1590,7 @@ proc generateRttiDestructor(g: ModuleGraph; typ: PType; owner: PSym; kind: TType
 
   dest.typ = getSysType(g, info, tyPointer)
 
-  result.typ = newProcType(info, nextTypeId(idgen), owner)
+  result.typ = newProcType(info, idgen, owner)
   result.typ.addParam dest
 
   var n = newNodeI(nkProcDef, info, bodyPos+1)
@@ -1638,6 +1681,13 @@ proc genDisplay(m: BModule; t: PType, depth: int): Rope =
   result.add seqs[0]
   result.add "}"
 
+proc genVTable(seqs: seq[PSym]): string =
+  result = "{"
+  for i in 0..<seqs.len:
+    if i > 0: result.add ", "
+    result.add "(void *) " & seqs[i].loc.r
+  result.add "}"
+
 proc genTypeInfoV2OldImpl(m: BModule; t, origType: PType, name: Rope; info: TLineInfo) =
   cgsym(m, "TNimTypeV2")
   m.s[cfsStrData].addf("N_LIB_PRIVATE TNimTypeV2 $1;$n", [name])
@@ -1674,6 +1724,14 @@ proc genTypeInfoV2OldImpl(m: BModule; t, origType: PType, name: Rope; info: TLin
     m.s[cfsVars].addf("static $1 $2[$3] = $4;$n", [getTypeDesc(m, getSysType(m.g.graph, unknownLineInfo, tyUInt32), dkVar), objDisplayStore, rope(objDepth+1), objDisplay])
     addf(typeEntry, "$1.display = $2;$n", [name, rope(objDisplayStore)])
 
+  let dispatchMethods = toSeq(getMethodsPerType(m.g.graph, t))
+  if dispatchMethods.len > 0:
+    let vTablePointerName = getTempName(m)
+    m.s[cfsVars].addf("static void* $1[$2] = $3;$n", [vTablePointerName, rope(dispatchMethods.len), genVTable(dispatchMethods)])
+    for i in dispatchMethods:
+      genProcPrototype(m, i)
+    addf(typeEntry, "$1.vTable = $2;$n", [name, vTablePointerName])
+
   m.s[cfsTypeInit3].add typeEntry
 
   if t.kind == tyObject and t.len > 0 and t[0] != nil and optEnableDeepCopy in m.config.globalOptions:
@@ -1715,8 +1773,16 @@ proc genTypeInfoV2Impl(m: BModule; t, origType: PType, name: Rope; info: TLineIn
   add(typeEntry, ", .traceImpl = (void*)")
   genHook(m, t, info, attachedTrace, typeEntry)
 
-  addf(typeEntry, ", .flags = $1};$n", [rope(flags)])
-  m.s[cfsVars].add typeEntry
+  let dispatchMethods = toSeq(getMethodsPerType(m.g.graph, t))
+  if dispatchMethods.len > 0:
+    addf(typeEntry, ", .flags = $1", [rope(flags)])
+    for i in dispatchMethods:
+      genProcPrototype(m, i)
+    addf(typeEntry, ", .vTable = $1};$n", [genVTable(dispatchMethods)])
+    m.s[cfsVars].add typeEntry
+  else:
+    addf(typeEntry, ", .flags = $1};$n", [rope(flags)])
+    m.s[cfsVars].add typeEntry
 
   if t.kind == tyObject and t.len > 0 and t[0] != nil and optEnableDeepCopy in m.config.globalOptions:
     discard genTypeInfoV1(m, t, info)
@@ -1754,16 +1820,16 @@ proc genTypeInfoV2(m: BModule; t: PType; info: TLineInfo): Rope =
     return prefixTI.rope & result & ")".rope
 
   m.g.typeInfoMarkerV2[sig] = (str: result, owner: owner)
-  if m.compileToCpp:
+  if m.compileToCpp or m.hcrOn:
     genTypeInfoV2OldImpl(m, t, origType, result, info)
   else:
     genTypeInfoV2Impl(m, t, origType, result, info)
   result = prefixTI.rope & result & ")".rope
 
 proc openArrayToTuple(m: BModule; t: PType): PType =
-  result = newType(tyTuple, nextTypeId m.idgen, t.owner)
-  let p = newType(tyPtr, nextTypeId m.idgen, t.owner)
-  let a = newType(tyUncheckedArray, nextTypeId m.idgen, t.owner)
+  result = newType(tyTuple, m.idgen, t.owner)
+  let p = newType(tyPtr, m.idgen, t.owner)
+  let a = newType(tyUncheckedArray, m.idgen, t.owner)
   a.add t.lastSon
   p.add a
   result.add p
@@ -1903,14 +1969,14 @@ proc genTypeInfo*(config: ConfigRef, m: BModule; t: PType; info: TLineInfo): Rop
   else:
     result = genTypeInfoV1(m, t, info)
 
-proc genTypeSection(m: BModule, n: PNode) = 
+proc genTypeSection(m: BModule, n: PNode) =
   var intSet = initIntSet()
   for i in 0..<n.len:
     if len(n[i]) == 0: continue
     if n[i][0].kind != nkPragmaExpr: continue
     for p in 0..<n[i][0].len:
       if (n[i][0][p].kind != nkSym): continue
-      if sfExportc in n[i][0][p].sym.flags:        
+      if sfExportc in n[i][0][p].sym.flags:
         discard getTypeDescAux(m, n[i][0][p].typ, intSet, descKindFromSymKind(n[i][0][p].sym.kind))
         if m.g.generatedHeader != nil:
           discard getTypeDescAux(m.g.generatedHeader, n[i][0][p].typ, intSet, descKindFromSymKind(n[i][0][p].sym.kind))

compiler/ccgutils.nim

@@ -10,22 +10,27 @@
 # This module declares some helpers for the C code generator.
 
 import
-  ast, types, hashes, strutils, msgs, wordrecg,
+  ast, types, msgs, wordrecg,
   platform, trees, options, cgendata
 
+import std/[hashes, strutils]
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
 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

compiler/cgen.nim

@@ -10,13 +10,15 @@
 ## This module implements the C code generator.
 
 import
-  ast, astalgo, hashes, trees, platform, magicsys, extccomp, options, intsets,
+  ast, astalgo, trees, platform, magicsys, extccomp, options,
   nversion, nimsets, msgs, bitsets, idents, types,
-  ccgutils, os, ropes, math, wordrecg, treetab, cgmeth,
+  ccgutils, ropes, wordrecg, treetab, cgmeth,
   rodutils, renderer, cgendata, aliases,
-  lowerings, tables, sets, ndi, lineinfos, pathutils, transf,
+  lowerings, ndi, lineinfos, pathutils, transf,
   injectdestructors, astmsgs, modulepaths, backendpragmas
 
+from expanddefaults import caseObjDefaultBranch
+
 import pipelineutils
 
 when defined(nimPreviewSlimSystem):
@@ -25,10 +27,10 @@ when defined(nimPreviewSlimSystem):
 when not defined(leanCompiler):
   import spawn, semparallel
 
-import strutils except `%`, addf # collides with ropes.`%`
+import std/strutils except `%`, addf # collides with ropes.`%`
 
 from ic / ic import ModuleBackendFlag
-import dynlib
+import std/[dynlib, math, tables, sets, os, intsets, hashes]
 
 when not declared(dynlib.libCandidates):
   proc libCandidates(s: string, dest: var seq[string]) =
@@ -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, flags: TLocFlags = {}) =
-  result.k = k
-  result.storage = s
-  result.lode = lode
-  result.r = ""
-  result.flags = 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
@@ -121,7 +121,7 @@ proc getModuleDllPath(m: BModule, module: int): Rope =
 proc getModuleDllPath(m: BModule, s: PSym): Rope =
   result = getModuleDllPath(m.g.modules[s.itemId.module])
 
-import macros
+import std/macros
 
 proc cgFormatValue(result: var string; value: string) =
   result.add value
@@ -291,6 +291,8 @@ 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:
@@ -299,6 +301,7 @@ proc genCLineDir(r: var Rope, p: BProc, info: TLineInfo; conf: ConfigRef) =
       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:
@@ -311,10 +314,10 @@ proc genLineDir(p: BProc, t: PNode) =
       (p.prc == nil or sfPure notin p.prc.flags) and t.info.fileIndex != InvalidFileIdx:
       if freshLine:
         if lastFileIndex == t.info.fileIndex:
-          linefmt(p, cpsStmts, "nimln_($1);\n",
+          linefmt(p, cpsStmts, "nimln_($1);",
               [line])
         else:
-          linefmt(p, cpsStmts, "nimlf_($1, $2);\n",
+          linefmt(p, cpsStmts, "nimlf_($1, $2);",
               [line, quotedFilename(p.config, t.info)])
 
 proc accessThreadLocalVar(p: BProc, s: PSym)
@@ -345,9 +348,12 @@ proc addRdLoc(a: TLoc; result: var Rope) =
 proc lenField(p: BProc): Rope {.inline.} =
   result = rope(if p.module.compileToCpp: "len" else: "Sup.len")
 
-proc lenExpr(p: BProc; a: TLoc): Rope =
+proc lenExpr(p: BProc; a: TLoc; isString = false): Rope =
   if optSeqDestructors in p.config.globalOptions:
-    result = rdLoc(a) & ".len"
+    if isString and p.config.isDefined("nimSeqsV3"):
+      result = ropecg(p.module, "(#nimStrLenV3($1))", [rdLoc(a)])
+    else:
+      result = rdLoc(a) & ".len"
   else:
     result = "($1 ? $1->$2 : 0)" % [rdLoc(a), lenField(p)]
 
@@ -357,12 +363,18 @@ proc dataFieldAccessor(p: BProc, sym: Rope): Rope =
   else:
     result = sym
 
-proc dataField(p: BProc): Rope =
+proc dataField(p: BProc; isString: bool = false): Rope =
+  # TODO: revisit this after unify strings and seqs
   if optSeqDestructors in p.config.globalOptions:
-    result = rope".p->data"
+    if isString and p.config.isDefined("nimSeqsV3"):
+      result = rope".p"
+    else:
+      result = rope".p->data"
   else:
     result = rope"->data"
 
+proc genProcPrototype(m: BModule, sym: PSym)
+
 include ccgliterals
 include ccgtypes
 
@@ -432,7 +444,7 @@ 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)
@@ -474,14 +486,19 @@ proc resetLoc(p: BProc, loc: var TLoc) =
     assert loc.r != ""
 
     let atyp = skipTypes(loc.t, abstractInst)
-    if atyp.kind in {tyVar, tyLent}:
-      linefmt(p, cpsStmts, "$1->len = 0; $1->p = NIM_NIL;$n", [rdLoc(loc)])
+    if p.config.isDefined("nimSeqsV3") and typ.kind == tyString:
+      if atyp.kind in {tyVar, tyLent}:
+        linefmt(p, cpsStmts, "$1->rawlen = 0; $1->p = NIM_NIL;$n", [rdLoc(loc)])
+      else:
+        linefmt(p, cpsStmts, "$1.rawlen = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
     else:
-      linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
+      if atyp.kind in {tyVar, tyLent}:
+        linefmt(p, cpsStmts, "$1->len = 0; $1->p = NIM_NIL;$n", [rdLoc(loc)])
+      else:
+        linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
   elif not isComplexValueType(typ):
     if containsGcRef:
-      var nilLoc: TLoc
-      initLoc(nilLoc, locTemp, loc.lode, OnStack)
+      var nilLoc: TLoc = initLoc(locTemp, loc.lode, OnStack)
       nilLoc.r = rope("NIM_NIL")
       genRefAssign(p, loc, nilLoc)
     else:
@@ -498,21 +515,32 @@ 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, descKindFromSymKind 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 constructLoc(p: BProc, loc: var TLoc, isTemp = false) =
   let typ = loc.t
-  if optSeqDestructors in p.config.globalOptions and skipTypes(typ, abstractInst + {tyStatic}).kind in {tyString, tySequence}:
-    linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
+  let typKind = skipTypes(typ, abstractInst + {tyStatic}).kind
+  if optSeqDestructors in p.config.globalOptions and typKind in {tyString, tySequence}:
+    if typKind == tyString and p.config.isDefined("nimSeqsV3"):
+      linefmt(p, cpsStmts, "$1.rawlen = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
+    else:
+      linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
   elif not isComplexValueType(typ):
     if containsGarbageCollectedRef(loc.t):
-      var nilLoc: TLoc
-      initLoc(nilLoc, locTemp, loc.lode, OnStack)
+      var nilLoc: TLoc = initLoc(locTemp, loc.lode, OnStack)
       nilLoc.r = rope("NIM_NIL")
       genRefAssign(p, loc, nilLoc)
     else:
@@ -539,17 +567,15 @@ 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, dkVar), result.r])
+    linefmt(p, cpsLocals, "$1 $2$3;$n", [getTypeDesc(p.module, t, dkVar), result.r,
+      genCppInitializer(p.module, p, t)])
   else:
     linefmt(p, cpsLocals, "$1 $2;$n", [getTypeDesc(p.module, t, dkVar), result.r])
-  result.k = locTemp
-  result.lode = lodeTyp t
-  result.storage = OnStack
-  result.flags = {}
   constructLoc(p, result, not needsInit)
   when false:
     # XXX Introduce a compiler switch in order to detect these easily.
@@ -560,25 +586,21 @@ 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) & "_"
+  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])
-  result.k = locTemp
-  result.lode = lodeTyp t
-  result.storage = OnStack
-  result.flags = {}
 
-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)
@@ -606,7 +628,10 @@ proc assignLocalVar(p: BProc, n: PNode) =
   # 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: "\n"
-  let decl = localVarDecl(p, n) & (if p.module.compileToCpp and isOrHasImportedCppType(n.typ): "{};" else: ";") & nl
+  var decl = localVarDecl(p, n)
+  if p.module.compileToCpp and isOrHasImportedCppType(n.typ):
+    decl.add genCppInitializer(p.module, p, n.typ)
+  decl.add ";" & nl
   line(p, cpsLocals, decl)
 
 include ccgthreadvars
@@ -640,17 +665,17 @@ proc genGlobalVarDecl(p: BProc, n: PNode; td, value: Rope; decl: var Rope) =
     else:
       decl = runtimeFormat(s.cgDeclFrmt & ";$n", [td, s.loc.r])
 
-proc genCppVarForCtor(p: BProc, v: PSym; vn, value: PNode; decl: var Rope)
+proc genCppVarForCtor(p: BProc; call: PNode; decl: var Rope)
 
 proc callGlobalVarCppCtor(p: BProc; v: PSym; vn, value: PNode) =
   let s = vn.sym
   fillBackendName(p.module, s)
   fillLoc(s.loc, locGlobalVar, vn, OnHeap)
-  var decl: Rope
+  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)
+  genCppVarForCtor(p, value, decl)
   p.module.s[cfsVars].add decl
 
 proc assignGlobalVar(p: BProc, n: PNode; value: Rope) =
@@ -728,19 +753,19 @@ proc genVarPrototype(m: BModule, n: PNode)
 proc requestConstImpl(p: BProc, sym: PSym)
 proc genStmts(p: BProc, t: PNode)
 proc expr(p: BProc, n: PNode, d: var TLoc)
-proc genProcPrototype(m: BModule, sym: PSym)
+
 proc putLocIntoDest(p: BProc, d: var TLoc, s: TLoc)
 proc intLiteral(i: BiggestInt; result: var Rope)
 proc genLiteral(p: BProc, n: PNode; result: var Rope)
 proc genOtherArg(p: BProc; ri: PNode; i: int; typ: PType; result: var Rope; argsCounter: var int)
 proc raiseExit(p: BProc)
 
-proc initLocExpr(p: BProc, e: PNode, result: var TLoc, flags: TLocFlags = {}) =
-  initLoc(result, locNone, e, OnUnknown, flags)
+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"
@@ -831,8 +856,7 @@ 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, dkVar), rdLoc(dest)])
@@ -867,11 +891,10 @@ 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" %
@@ -986,11 +1009,19 @@ 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
@@ -998,11 +1029,8 @@ 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
@@ -1127,7 +1155,7 @@ 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]
@@ -1145,14 +1173,15 @@ proc isNoReturn(m: BModule; s: PSym): bool {.inline.} =
 proc genProcAux*(m: BModule, prc: PSym) =
   var p = newProc(prc, m)
   var header = newRopeAppender()
-  if m.config.backend == backendCpp and {sfVirtual, sfConstructor} * prc.flags != {}:
+  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)
 
-  var procBody = transformBody(m.g.graph, m.idgen, prc, dontUseCache)
+  var procBody = transformBody(m.g.graph, m.idgen, prc, {})
   if sfInjectDestructors in prc.flags:
     procBody = injectDestructorCalls(m.g.graph, m.idgen, prc, procBody)
 
@@ -1168,16 +1197,22 @@ proc genProcAux*(m: BModule, prc: PSym) =
       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:
+      resNode.sym.loc.flags.incl lfIndirect
       fillLoc(resNode.sym.loc, locParam, resNode, "this", OnHeap)
     else:
       fillResult(p.config, resNode, prc.typ)
@@ -1205,13 +1240,13 @@ proc genProcAux*(m: BModule, prc: PSym) =
 
   prc.info = tmpInfo
 
-  var generatedProc: Rope
+  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)])
@@ -1256,7 +1291,7 @@ proc requiresExternC(m: BModule; sym: PSym): bool {.inline.} =
 
 proc genProcPrototype(m: BModule, sym: PSym) =
   useHeader(m, sym)
-  if lfNoDecl in sym.loc.flags or {sfVirtual, sfConstructor} * sym.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):
@@ -1435,17 +1470,21 @@ 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 =
@@ -1464,10 +1503,10 @@ 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)
@@ -1491,7 +1530,7 @@ proc genMainProc(m: BModule) =
   else:
     preMainCode.add("\t$1PreMain();\L" % [rope m.config.nimMainPrefix])
 
-  var posixCmdLine: Rope
+  var posixCmdLine: Rope = ""
   if optNoMain notin m.config.globalOptions:
     posixCmdLine.add "N_LIB_PRIVATE int cmdCount;\L"
     posixCmdLine.add "N_LIB_PRIVATE char** cmdLine;\L"
@@ -1880,13 +1919,13 @@ 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", [])
 
@@ -1986,7 +2025,7 @@ 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)
@@ -2161,7 +2200,7 @@ proc updateCachedModule(m: BModule) =
   cf.flags = {CfileFlag.Cached}
   addFileToCompile(m.config, cf)
 
-proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode): PNode =
+proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode) =
   ## Also called from IC.
   if sfMainModule in m.module.flags:
     # phase ordering problem here: We need to announce this
@@ -2210,7 +2249,11 @@ proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode): PNode =
 
       if m.g.forwardedProcs.len == 0:
         incl m.flags, objHasKidsValid
-      result = generateMethodDispatchers(graph, m.idgen)
+      if optMultiMethods in m.g.config.globalOptions or
+          m.g.config.selectedGC notin {gcArc, gcOrc, gcAtomicArc} or
+          vtables notin m.g.config.features:
+        generateIfMethodDispatchers(graph, m.idgen)
+
 
   let mm = m
   m.g.modulesClosed.add mm

compiler/cgendata.nim

@@ -10,8 +10,10 @@
 ## This module contains the data structures for the C code generation phase.
 
 import
-  ast, ropes, options, intsets,
-  tables, ndi, lineinfos, pathutils, modulegraphs, sets
+  ast, ropes, options,
+  ndi, lineinfos, pathutils, modulegraphs
+
+import std/[intsets, tables, sets]
 
 type
   TLabel* = Rope              # for the C generator a label is just a rope
@@ -196,6 +198,8 @@ proc newProc*(prc: PSym, module: BModule): BProc =
   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()],

compiler/cgmeth.nim

@@ -10,12 +10,15 @@
 ## This module implements code generation for methods.
 
 import
-  intsets, options, ast, msgs, idents, renderer, types, magicsys,
-  sempass2, modulegraphs, lineinfos
+  options, ast, msgs, idents, renderer, types, magicsys,
+  sempass2, modulegraphs, lineinfos, astalgo
+
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
+import std/[tables]
 
 proc genConv(n: PNode, d: PType, downcast: bool; conf: ConfigRef): PNode =
   var dest = skipTypes(d, abstractPtrs)
@@ -44,6 +47,8 @@ proc getDispatcher*(s: PSym): PSym =
   if dispatcherPos < s.ast.len:
     result = s.ast[dispatcherPos].sym
     doAssert sfDispatcher in result.flags
+  else:
+    result = nil
 
 proc methodCall*(n: PNode; conf: ConfigRef): PNode =
   result = n
@@ -62,6 +67,7 @@ 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
@@ -95,7 +101,8 @@ proc sameMethodBucket(a, b: PSym; multiMethods: bool): MethodResult =
       return No
   if result == Yes:
     # check for return type:
-    if not sameTypeOrNil(a.typ[0], b.typ[0]):
+    # ignore flags of return types; # bug #22673
+    if not sameTypeOrNil(a.typ[0], b.typ[0], {IgnoreFlags}):
       if b.typ[0] != nil and b.typ[0].kind == tyUntyped:
         # infer 'auto' from the base to make it consistent:
         b.typ[0] = a.typ[0]
@@ -117,7 +124,7 @@ proc createDispatcher(s: PSym; g: ModuleGraph; idgen: IdGenerator): PSym =
   incl(disp.flags, sfDispatcher)
   excl(disp.flags, sfExported)
   let old = disp.typ
-  disp.typ = copyType(disp.typ, nextTypeId(idgen), disp.typ.owner)
+  disp.typ = copyType(disp.typ, idgen, disp.typ.owner)
   copyTypeProps(g, idgen.module, disp.typ, old)
 
   # we can't inline the dispatcher itself (for now):
@@ -149,7 +156,10 @@ proc fixupDispatcher(meth, disp: PSym; conf: ConfigRef) =
     disp.ast[resultPos] = copyTree(meth.ast[resultPos])
 
 proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
-  var witness: PSym
+  var witness: PSym = nil
+  if s.typ[1].owner.getModule != s.getModule and vtables in g.config.features and not g.config.isDefined("nimInternalNonVtablesTesting"):
+    localError(g.config, s.info, errGenerated, "method `" & s.name.s &
+          "` can be defined only in the same module with its type (" & s.typ[1].typeToString() & ")")
   for i in 0..<g.methods.len:
     let disp = g.methods[i].dispatcher
     case sameMethodBucket(disp, s, multimethods = optMultiMethods in g.config.globalOptions)
@@ -168,6 +178,11 @@ proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
     of Invalid:
       if witness.isNil: witness = g.methods[i].methods[0]
   # create a new dispatcher:
+  # stores the id and the position
+  if s.typ[1].skipTypes(skipPtrs).itemId notin g.bucketTable:
+    g.bucketTable[s.typ[1].skipTypes(skipPtrs).itemId] = 1
+  else:
+    g.bucketTable.inc(s.typ[1].skipTypes(skipPtrs).itemId)
   g.methods.add((methods: @[s], dispatcher: createDispatcher(s, g, idgen)))
   #echo "adding ", s.info
   if witness != nil:
@@ -176,8 +191,9 @@ proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
   elif sfBase notin s.flags:
     message(g.config, s.info, warnUseBase)
 
-proc relevantCol(methods: seq[PSym], col: int): bool =
+proc relevantCol*(methods: seq[PSym], col: int): bool =
   # returns true iff the position is relevant
+  result = false
   var t = methods[0].typ[col].skipTypes(skipPtrs)
   if t.kind == tyObject:
     for i in 1..high(methods):
@@ -186,6 +202,7 @@ 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)
@@ -194,7 +211,7 @@ proc cmpSignatures(a, b: PSym, relevantCols: IntSet): int =
       if (d != high(int)) and d != 0:
         return d
 
-proc sortBucket(a: var seq[PSym], relevantCols: IntSet) =
+proc sortBucket*(a: var seq[PSym], relevantCols: IntSet) =
   # we use shellsort here; fast and simple
   var n = a.len
   var h = 1
@@ -213,7 +230,7 @@ proc sortBucket(a: var seq[PSym], relevantCols: IntSet) =
       a[j] = v
     if h == 1: break
 
-proc genDispatcher(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet; idgen: IdGenerator): PSym =
+proc genIfDispatcher*(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet; idgen: IdGenerator): PSym =
   var base = methods[0].ast[dispatcherPos].sym
   result = base
   var paramLen = base.typ.len
@@ -272,8 +289,7 @@ proc genDispatcher(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet; idg
   nilchecks.flags.incl nfTransf # should not be further transformed
   result.ast[bodyPos] = nilchecks
 
-proc generateMethodDispatchers*(g: ModuleGraph, idgen: IdGenerator): PNode =
-  result = newNode(nkStmtList)
+proc generateIfMethodDispatchers*(g: ModuleGraph, idgen: IdGenerator) =
   for bucket in 0..<g.methods.len:
     var relevantCols = initIntSet()
     for col in 1..<g.methods[bucket].methods[0].typ.len:
@@ -282,4 +298,4 @@ proc generateMethodDispatchers*(g: ModuleGraph, idgen: IdGenerator): 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, idgen))
+    g.addDispatchers genIfDispatcher(g, g.methods[bucket].methods, relevantCols, idgen)

compiler/closureiters.nim

@@ -134,7 +134,9 @@
 import
   ast, msgs, idents,
   renderer, magicsys, lowerings, lambdalifting, modulegraphs, lineinfos,
-  tables, options
+  options
+
+import std/tables
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -258,8 +260,9 @@ 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 +328,7 @@ 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 +391,22 @@ 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 +501,7 @@ 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)
@@ -1154,9 +1160,9 @@ proc skipThroughEmptyStates(ctx: var Ctx, n: PNode): PNode=
       n[i] = ctx.skipThroughEmptyStates(n[i])
 
 proc newArrayType(g: ModuleGraph; n: int, t: PType; idgen: IdGenerator; owner: PSym): PType =
-  result = newType(tyArray, nextTypeId(idgen), owner)
+  result = newType(tyArray, idgen, owner)
 
-  let rng = newType(tyRange, nextTypeId(idgen), owner)
+  let rng = newType(tyRange, idgen, owner)
   rng.n = newTree(nkRange, g.newIntLit(owner.info, 0), g.newIntLit(owner.info, n - 1))
   rng.rawAddSon(t)
 
@@ -1361,6 +1367,7 @@ 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

compiler/cmdlinehelper.nim

@@ -11,7 +11,9 @@
 
 import
   options, idents, nimconf, extccomp, commands, msgs,
-  lineinfos, modulegraphs, condsyms, os, pathutils, parseopt
+  lineinfos, modulegraphs, condsyms, pathutils
+
+import std/[os, parseopt]
 
 proc prependCurDir*(f: AbsoluteFile): AbsoluteFile =
   when defined(unix):

compiler/commands.nim

@@ -27,7 +27,9 @@ bootSwitch(usedNoGC, defined(nogc), "--gc:none")
 import std/[setutils, os, strutils, parseutils, parseopt, sequtils, strtabs]
 import
   msgs, options, nversion, condsyms, extccomp, platform,
-  wordrecg, nimblecmd, lineinfos, pathutils, pathnorm
+  wordrecg, nimblecmd, lineinfos, pathutils
+
+import std/pathnorm
 
 from ast import setUseIc, eqTypeFlags, tfGcSafe, tfNoSideEffect
 
@@ -184,7 +186,7 @@ proc processSpecificNote*(arg: string, state: TSpecialWord, pass: TCmdLinePass,
                          info: TLineInfo; orig: string; conf: ConfigRef) =
   var id = ""  # arg = key or [key] or key:val or [key]:val;  with val=on|off
   var i = 0
-  var notes: set[TMsgKind]
+  var notes: set[TMsgKind] = {}
   var isBracket = false
   if i < arg.len and arg[i] == '[':
     isBracket = true
@@ -205,7 +207,11 @@ proc processSpecificNote*(arg: string, state: TSpecialWord, pass: TCmdLinePass,
     # unfortunately, hintUser and warningUser clash, otherwise implementation would simplify a bit
     let x = findStr(noteMin, noteMax, id, errUnknown)
     if x != errUnknown: notes = {TNoteKind(x)}
-    else: localError(conf, info, "unknown $#: $#" % [name, id])
+    else:
+      if isSomeHint:
+        message(conf, info, hintUnknownHint, id)
+      else:
+        localError(conf, info, "unknown $#: $#" % [name, id])
   case id.normalize
   of "all": # other note groups would be easy to support via additional cases
     notes = if isSomeHint: {hintMin..hintMax} else: {warnMin..warnMax}
@@ -263,13 +269,17 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
     of "none": result = conf.selectedGC == gcNone
     of "stack", "regions": result = conf.selectedGC == gcRegions
     of "atomicarc": result = conf.selectedGC == gcAtomicArc
-    else: localError(conf, info, errNoneBoehmRefcExpectedButXFound % arg)
+    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
@@ -279,7 +289,9 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
                       not contains(conf.globalOptions, optGenGuiApp)
     of "staticlib": result = contains(conf.globalOptions, optGenStaticLib) and
                       not contains(conf.globalOptions, optGenGuiApp)
-    else: localError(conf, info, errGuiConsoleOrLibExpectedButXFound % arg)
+    else:
+      result = false
+      localError(conf, info, errGuiConsoleOrLibExpectedButXFound % arg)
   of "dynliboverride":
     result = isDynlibOverride(conf, arg)
   of "exceptions":
@@ -288,8 +300,12 @@ proc testCompileOptionArg*(conf: ConfigRef; switch, arg: string, info: TLineInfo
     of "setjmp": result = conf.exc == excSetjmp
     of "quirky": result = conf.exc == excQuirky
     of "goto": result = conf.exc == excGoto
-    else: localError(conf, info, errInvalidExceptionSystem % arg)
-  else: invalidCmdLineOption(conf, passCmd1, switch, info)
+    else:
+      result = false
+      localError(conf, info, errInvalidExceptionSystem % arg)
+  else:
+    result = false
+    invalidCmdLineOption(conf, passCmd1, switch, info)
 
 proc testCompileOption*(conf: ConfigRef; switch: string, info: TLineInfo): bool =
   case switch.normalize
@@ -335,10 +351,14 @@ proc testCompileOption*(conf: ConfigRef; switch: string, info: TLineInfo): bool
     if switch.normalize == "patterns": deprecatedAlias(switch, "trmacros")
     result = contains(conf.options, optTrMacros)
   of "excessivestacktrace": result = contains(conf.globalOptions, optExcessiveStackTrace)
-  of "nilseqs", "nilchecks", "taintmode": warningOptionNoop(switch)
+  of "nilseqs", "nilchecks", "taintmode":
+    warningOptionNoop(switch)
+    result = false
   of "panics": result = contains(conf.globalOptions, optPanics)
   of "jsbigint64": result = contains(conf.globalOptions, optJsBigInt64)
-  else: invalidCmdLineOption(conf, passCmd1, switch, info)
+  else:
+    result = false
+    invalidCmdLineOption(conf, passCmd1, switch, info)
 
 proc processPath(conf: ConfigRef; path: string, info: TLineInfo,
                  notRelativeToProj = false): AbsoluteDir =
@@ -380,7 +400,8 @@ proc makeAbsolute(s: string): AbsoluteFile =
 proc setTrackingInfo(conf: ConfigRef; dirty, file, line, column: string,
                      info: TLineInfo) =
   ## set tracking info, common code for track, trackDirty, & ideTrack
-  var ln, col: int
+  var ln: int = 0
+  var col: int = 0
   if parseUtils.parseInt(line, ln) <= 0:
     localError(conf, info, errInvalidNumber % line)
   if parseUtils.parseInt(column, col) <= 0:
@@ -441,10 +462,12 @@ proc handleCmdInput*(conf: ConfigRef) =
 proc parseCommand*(command: string): Command =
   case command.normalize
   of "c", "cc", "compile", "compiletoc": cmdCompileToC
+  of "nir": cmdCompileToNir
   of "cpp", "compiletocpp": cmdCompileToCpp
   of "objc", "compiletooc": cmdCompileToOC
   of "js", "compiletojs": cmdCompileToJS
   of "r": cmdCrun
+  of "m": cmdM
   of "run": cmdTcc
   of "check": cmdCheck
   of "e": cmdNimscript
@@ -477,6 +500,7 @@ proc setCmd*(conf: ConfigRef, cmd: Command) =
   of cmdCompileToCpp: conf.backend = backendCpp
   of cmdCompileToOC: conf.backend = backendObjc
   of cmdCompileToJS: conf.backend = backendJs
+  of cmdCompileToNir: conf.backend = backendNir
   else: discard
 
 proc setCommandEarly*(conf: ConfigRef, command: string) =
@@ -589,10 +613,17 @@ proc processMemoryManagementOption(switch, arg: string, pass: TCmdLinePass,
       defineSymbol(conf.symbols, "gcregions")
     else: localError(conf, info, errNoneBoehmRefcExpectedButXFound % arg)
 
+proc pathRelativeToConfig(arg: string, pass: TCmdLinePass, conf: ConfigRef): string =
+  if pass == passPP and not isAbsolute(arg):
+    assert isAbsolute(conf.currentConfigDir), "something is wrong with currentConfigDir"
+    result = conf.currentConfigDir / arg
+  else:
+    result = arg
+
 proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
                     conf: ConfigRef) =
-  var
-    key, val: string
+  var key = ""
+  var val = ""
   case switch.normalize
   of "eval":
     expectArg(conf, switch, arg, pass, info)
@@ -607,8 +638,7 @@ 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)
@@ -618,8 +648,7 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
         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":
@@ -636,7 +665,7 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     # refs bug #18674, otherwise `--os:windows` messes up with `--nimcache` set
     # in config nims files, e.g. via: `import os; switch("nimcache", "/tmp/somedir")`
     if conf.target.targetOS == osWindows and DirSep == '/': arg = arg.replace('\\', '/')
-    conf.nimcacheDir = processPath(conf, arg, info, notRelativeToProj=true)
+    conf.nimcacheDir = processPath(conf, pathRelativeToConfig(arg, pass, conf), info, notRelativeToProj=true)
   of "out", "o":
     expectArg(conf, switch, arg, pass, info)
     let f = splitFile(processPath(conf, arg, info, notRelativeToProj=true).string)
@@ -770,7 +799,10 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     if conf.backend == backendJs or conf.cmd == cmdNimscript: discard
     else: processOnOffSwitchG(conf, {optThreads}, arg, pass, info)
     #if optThreads in conf.globalOptions: conf.setNote(warnGcUnsafe)
-  of "tlsemulation": processOnOffSwitchG(conf, {optTlsEmulation}, arg, pass, info)
+  of "tlsemulation":
+    processOnOffSwitchG(conf, {optTlsEmulation}, arg, pass, info)
+    if optTlsEmulation in conf.globalOptions:
+      conf.legacyFeatures.incl emitGenerics
   of "implicitstatic":
     processOnOffSwitch(conf, {optImplicitStatic}, arg, pass, info)
   of "patterns", "trmacros":
@@ -878,15 +910,19 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
       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)
@@ -900,7 +936,9 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     conf.mainPackageNotes = conf.notes
   of "parallelbuild":
     expectArg(conf, switch, arg, pass, info)
-    conf.numberOfProcessors = parseInt(arg)
+    var value: int = 0
+    discard parseSaturatedNatural(arg, value)
+    conf.numberOfProcessors = value
   of "version", "v":
     expectNoArg(conf, switch, arg, pass, info)
     writeVersionInfo(conf, pass)
@@ -1109,7 +1147,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
     else: invalidCmdLineOption(conf, pass, switch, info)
 
 proc processCommand*(switch: string, pass: TCmdLinePass; config: ConfigRef) =
-  var cmd, arg: string
+  var cmd = ""
+  var arg = ""
   splitSwitch(config, switch, cmd, arg, pass, gCmdLineInfo)
   processSwitch(cmd, arg, pass, gCmdLineInfo, config)
 
@@ -1136,7 +1175,10 @@ proc processArgument*(pass: TCmdLinePass; p: OptParser;
       config.projectName = unixToNativePath(p.key)
       config.arguments = cmdLineRest(p)
       result = true
-    elif pass != passCmd2: setCommandEarly(config, p.key)
+    elif pass != passCmd2:
+      setCommandEarly(config, p.key)
+      result = false
+    else: result = false
   else:
     if pass == passCmd1: config.commandArgs.add p.key
     if argsCount == 1:
@@ -1147,4 +1189,6 @@ proc processArgument*(pass: TCmdLinePass; p: OptParser;
         config.projectName = unixToNativePath(p.key)
       config.arguments = cmdLineRest(p)
       result = true
+    else:
+      result = false
   inc argsCount

compiler/concepts.nim

@@ -11,9 +11,9 @@
 ## for details. Note this is a first implementation and only the "Concept matching"
 ## section has been implemented.
 
-import ast, astalgo, semdata, lookups, lineinfos, idents, msgs, renderer, types, intsets
+import ast, astalgo, semdata, lookups, lineinfos, idents, msgs, renderer, types
 
-from magicsys import addSonSkipIntLit
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -28,23 +28,11 @@ 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"), c.idgen, ow, info)
-  s.typ = newType(tyTypeDesc, nextTypeId(c.idgen), ow)
+  s.typ = newType(tyTypeDesc, c.idgen, ow)
   s.typ.flags.incl {tfUnresolved, tfPacked}
-  s.typ.add newType(tyEmpty, nextTypeId(c.idgen), ow)
+  s.typ.add newType(tyEmpty, c.idgen, ow)
   addDecl(c, s, info)
 
-proc isSelf*(t: PType): bool {.inline.} =
-  ## Is this the magical 'Self' type?
-  t.kind == tyTypeDesc and tfPacked in t.flags
-
-proc makeTypeDesc*(c: PContext, typ: PType): PType =
-  if typ.kind == tyTypeDesc and not isSelf(typ):
-    result = typ
-  else:
-    result = newTypeS(tyTypeDesc, c)
-    incl result.flags, tfCheckedForDestructor
-    result.addSonSkipIntLit(typ, c.idgen)
-
 proc semConceptDecl(c: PContext; n: PNode): PNode =
   ## Recursive helper for semantic checking for the concept declaration.
   ## Currently we only support (possibly empty) lists of statements
@@ -121,8 +109,11 @@ 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 +147,17 @@ 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 +178,7 @@ 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 +203,7 @@ 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 +252,7 @@ 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
 

compiler/condsyms.nim

@@ -10,7 +10,7 @@
 # This module handles the conditional symbols.
 
 import
-  strtabs
+  std/strtabs
 
 from options import Feature
 from lineinfos import hintMin, hintMax, warnMin, warnMax
@@ -143,7 +143,6 @@ proc initDefines*(symbols: StringTableRef) =
   defineSymbol("nimHasTemplateRedefinitionPragma")
   defineSymbol("nimHasCstringCase")
   defineSymbol("nimHasCallsitePragma")
-  defineSymbol("nimHasAmbiguousEnumHint")
 
   defineSymbol("nimHasWarnCastSizes") # deadcode
   defineSymbol("nimHasOutParams")
@@ -158,3 +157,12 @@ proc initDefines*(symbols: StringTableRef) =
   defineSymbol("nimAllowNonVarDestructor")
   defineSymbol("nimHasQuirky")
   defineSymbol("nimHasEnsureMove")
+
+  defineSymbol("nimUseStrictDefs")
+  defineSymbol("nimHasNolineTooLong")
+
+  defineSymbol("nimHasCastExtendedVm")
+  defineSymbol("nimHasWarnStdPrefix")
+
+  defineSymbol("nimHasVtables")
+  defineSymbol("nimHasSeqsV3")

compiler/depends.nim

@@ -14,7 +14,7 @@ import options, ast, ropes, pathutils, msgs, lineinfos
 import modulegraphs
 
 import std/[os, parseutils]
-import strutils except addf
+import std/strutils except addf
 import std/private/globs
 
 when defined(nimPreviewSlimSystem):
@@ -42,7 +42,7 @@ proc toNimblePath(s: string, isStdlib: bool): string =
     let sub = "lib/"
     var start = s.find(sub)
     if start < 0:
-      doAssert false
+      raiseAssert "unreachable"
     else:
       start += sub.len
       let base = s[start..^1]
@@ -105,11 +105,6 @@ proc generateDot*(graph: ModuleGraph; project: AbsoluteFile) =
             changeFileExt(project, "dot"))
 
 proc setupDependPass*(graph: ModuleGraph; module: PSym; idgen: IdGenerator): PPassContext =
-  var g: PGen
-  new(g)
-  g.module = module
-  g.config = graph.config
-  g.graph = graph
+  result = PGen(module: module, config: graph.config, graph: graph)
   if graph.backend == nil:
     graph.backend = Backend(dotGraph: "")
-  result = g

compiler/dfa.nim

@@ -22,8 +22,9 @@
 ## "A Graph–Free Approach to Data–Flow Analysis" by Markus Mohnen.
 ## https://link.springer.com/content/pdf/10.1007/3-540-45937-5_6.pdf
 
-import ast, intsets, lineinfos, renderer, aliasanalysis
+import ast, lineinfos, renderer, aliasanalysis
 import std/private/asciitables
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -60,6 +61,7 @@ type
 proc codeListing(c: ControlFlowGraph, start = 0; last = -1): string =
   # for debugging purposes
   # first iteration: compute all necessary labels:
+  result = ""
   var jumpTargets = initIntSet()
   let last = if last < 0: c.len-1 else: min(last, c.len-1)
   for i in start..last:
@@ -111,7 +113,7 @@ proc patch(c: var Con, p: TPosition) =
 proc gen(c: var Con; n: PNode)
 
 proc popBlock(c: var Con; oldLen: int) =
-  var exits: seq[TPosition]
+  var exits: seq[TPosition] = @[]
   exits.add c.gotoI()
   for f in c.blocks[oldLen].breakFixups:
     c.patch(f[0])
@@ -128,10 +130,6 @@ template withBlock(labl: PSym; body: untyped) =
   body
   popBlock(c, oldLen)
 
-proc isTrue(n: PNode): bool =
-  n.kind == nkSym and n.sym.kind == skEnumField and n.sym.position != 0 or
-    n.kind == nkIntLit and n.intVal != 0
-
 template forkT(body) =
   let lab1 = c.forkI()
   body
@@ -263,7 +261,7 @@ 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]
+    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):
@@ -469,7 +467,7 @@ 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:

compiler/docgen.nim

@@ -15,15 +15,16 @@
 ## For corresponding users' documentation see [Nim DocGen Tools Guide].
 
 import
-  ast, strutils, strtabs, algorithm, sequtils, options, msgs, os, idents,
+  ast, options, msgs, idents,
   wordrecg, syntaxes, renderer, lexer,
   packages/docutils/[rst, rstidx, rstgen, dochelpers],
-  json, xmltree, trees, types,
-  typesrenderer, astalgo, lineinfos, intsets,
-  pathutils, tables, nimpaths, renderverbatim, osproc, packages
+  trees, types,
+  typesrenderer, astalgo, lineinfos,
+  pathutils, nimpaths, renderverbatim, packages
 import packages/docutils/rstast except FileIndex, TLineInfo
 
-from uri import encodeUrl
+import std/[os, strutils, strtabs, algorithm, json, osproc, tables, intsets, xmltree, sequtils]
+from std/uri import encodeUrl
 from nodejs import findNodeJs
 
 when defined(nimPreviewSlimSystem):
@@ -170,6 +171,7 @@ proc cmpDecimalsIgnoreCase(a, b: string): int =
 
 proc prettyString(a: object): string =
   # xxx pending std/prettyprint refs https://github.com/nim-lang/RFCs/issues/203#issuecomment-602534906
+  result = ""
   for k, v in fieldPairs(a):
     result.add k & ": " & $v & "\n"
 
@@ -215,12 +217,16 @@ proc whichType(d: PDoc; n: PNode): PSym =
   if n.kind == nkSym:
     if d.types.strTableContains(n.sym):
       result = n.sym
+    else:
+      result = nil
   else:
+    result = nil
     for i in 0..<n.safeLen:
       let x = whichType(d, n[i])
       if x != nil: return x
 
 proc attachToType(d: PDoc; p: PSym): PSym =
+  result = nil
   let params = p.ast[paramsPos]
   template check(i) =
     result = whichType(d, params[i])
@@ -343,7 +349,7 @@ proc newDocumentor*(filename: AbsoluteFile; cache: IdentCache; conf: ConfigRef,
 
   if conf.configVars.hasKey("doc.googleAnalytics") and
       conf.configVars.hasKey("doc.plausibleAnalytics"):
-    doAssert false, "Either use googleAnalytics or plausibleAnalytics"
+    raiseAssert "Either use googleAnalytics or plausibleAnalytics"
 
   if conf.configVars.hasKey("doc.googleAnalytics"):
     result.analytics = """
@@ -368,7 +374,7 @@ proc newDocumentor*(filename: AbsoluteFile; cache: IdentCache; conf: ConfigRef,
   result.seenSymbols = newStringTable(modeCaseInsensitive)
   result.id = 100
   result.jEntriesFinal = newJArray()
-  initStrTable result.types
+  result.types = initStrTable()
   result.onTestSnippet =
     proc (gen: var RstGenerator; filename, cmd: string; status: int; content: string) {.gcsafe.} =
       if conf.docCmd == docCmdSkip: return
@@ -435,6 +441,8 @@ proc genComment(d: PDoc, n: PNode): PRstNode =
                         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
@@ -469,6 +477,7 @@ proc getPlainDocstring(n: PNode): string =
   elif startsWith(n.comment, "##"):
     result = n.comment
   else:
+    result = ""
     for i in 0..<n.safeLen:
       result = getPlainDocstring(n[i])
       if result.len > 0: return
@@ -484,9 +493,8 @@ proc externalDep(d: PDoc; module: PSym): string =
 proc nodeToHighlightedHtml(d: PDoc; n: PNode; result: var string;
                            renderFlags: TRenderFlags = {};
                            procLink: string) =
-  var r: TSrcGen
+  var r: TSrcGen = initTokRender(n, renderFlags)
   var literal = ""
-  initTokRender(r, n, renderFlags)
   var kind = tkEof
   var tokenPos = 0
   var procTokenPos = 0
@@ -600,7 +608,9 @@ proc runAllExamples(d: PDoc) =
       rawMessage(d.conf, hintSuccess, ["runnableExamples: " & outp.string])
       # removeFile(outp.changeFileExt(ExeExt)) # it's in nimcache, no need to remove
 
-proc quoted(a: string): string = result.addQuoted(a)
+proc quoted(a: string): string =
+  result = ""
+  result.addQuoted(a)
 
 proc toInstantiationInfo(conf: ConfigRef, info: TLineInfo): (string, int, int) =
   # xxx expose in compiler/lineinfos.nim
@@ -726,7 +736,7 @@ proc getAllRunnableExamplesImpl(d: PDoc; n: PNode, dest: var ItemPre,
         let (rdoccmd, code) = prepareExample(d, n, topLevel)
         var msg = "Example:"
         if rdoccmd.len > 0: msg.add " cmd: " & rdoccmd
-        var s: string
+        var s: string = ""
         dispA(d.conf, s, "\n<p><strong class=\"examples_text\">$1</strong></p>\n",
             "\n\n\\textbf{$1}\n", [msg])
         dest.add s
@@ -942,14 +952,17 @@ proc genDeprecationMsg(d: PDoc, n: PNode): string =
     if n[1].kind in {nkStrLit..nkTripleStrLit}:
       result = getConfigVar(d.conf, "doc.deprecationmsg") % [
           "label", "Deprecated:", "message", xmltree.escape(n[1].strVal)]
+    else:
+      result = ""
   else:
-    doAssert false
+    raiseAssert "unreachable"
 
 type DocFlags = enum
   kDefault
   kForceExport
 
 proc genSeeSrc(d: PDoc, path: string, line: int): string =
+  result = ""
   let docItemSeeSrc = getConfigVar(d.conf, "doc.item.seesrc")
   if docItemSeeSrc.len > 0:
     let path = relativeTo(AbsoluteFile path, AbsoluteDir getCurrentDir(), '/')
@@ -991,7 +1004,7 @@ 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:
@@ -1016,8 +1029,7 @@ 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:
@@ -1038,15 +1050,14 @@ 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)
@@ -1154,7 +1165,7 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
     renderFlags = {renderNoBody, renderNoComments, renderDocComments, renderExpandUsing}
   if nonExports:
     renderFlags.incl renderNonExportedFields
-  initTokRender(r, n, renderFlags)
+  r = initTokRender(n, renderFlags)
   result.json = %{ "name": %name, "type": %($k), "line": %n.info.line.int,
                    "col": %n.info.col}
   if comm != nil:
@@ -1186,9 +1197,9 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
       result.json["signature"]["genericParams"] = newJArray()
       for genericParam in n[genericParamsPos]:
         var param = %{"name": %($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:
@@ -1283,6 +1294,8 @@ 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)
@@ -1305,6 +1318,8 @@ 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
@@ -1318,6 +1333,8 @@ 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
@@ -1391,7 +1408,7 @@ 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
@@ -1500,7 +1517,7 @@ 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") % (
@@ -1526,7 +1543,7 @@ 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
@@ -1641,7 +1658,7 @@ 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") % [
@@ -1672,7 +1689,7 @@ 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 = ""
@@ -1723,7 +1740,7 @@ 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
@@ -1781,7 +1798,7 @@ 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,
@@ -1789,11 +1806,11 @@ proc writeOutputJson*(d: PDoc, useWarning = false) =
     "moduleDescription": modDesc,
     "entries": d.jEntriesFinal}
   if optStdout in d.conf.globalOptions:
-    write(stdout, $content)
+    writeLine(stdout, $content)
   else:
     let dir = d.destFile.splitFile.dir
     createDir(dir)
-    var f: File
+    var f: File = default(File)
     if open(f, d.destFile, fmWrite):
       write(f, $content)
       close(f)
@@ -1907,7 +1924,7 @@ 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)
 

compiler/enumtostr.nim

@@ -14,7 +14,7 @@ proc genEnumToStrProc*(t: PType; info: TLineInfo; g: ModuleGraph; idgen: IdGener
   let res = newSym(skResult, getIdent(g.cache, "result"), idgen, result, info)
   res.typ = getSysType(g, info, tyString)
 
-  result.typ = newType(tyProc, nextTypeId idgen, t.owner)
+  result.typ = newType(tyProc, idgen, t.owner)
   result.typ.n = newNodeI(nkFormalParams, info)
   rawAddSon(result.typ, res.typ)
   result.typ.n.add newNodeI(nkEffectList, info)
@@ -56,6 +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
@@ -75,7 +76,7 @@ proc genCaseObjDiscMapping*(t: PType; field: PSym; info: TLineInfo; g: ModuleGra
   let res = newSym(skResult, getIdent(g.cache, "result"), idgen, result, info)
   res.typ = getSysType(g, info, tyUInt8)
 
-  result.typ = newType(tyProc, nextTypeId idgen, t.owner)
+  result.typ = newType(tyProc, idgen, t.owner)
   result.typ.n = newNodeI(nkFormalParams, info)
   rawAddSon(result.typ, res.typ)
   result.typ.n.add newNodeI(nkEffectList, info)

compiler/errorhandling.nim

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

compiler/evalffi.nim

@@ -9,9 +9,11 @@
 
 ## This file implements the FFI part of the evaluator for Nim code.
 
-import ast, types, options, tables, dynlib, msgs, lineinfos
-from os import getAppFilename
-import pkg/libffi
+import ast, types, options, msgs, lineinfos
+from std/os import getAppFilename
+import libffi/libffi
+
+import std/[tables, dynlib]
 
 when defined(windows):
   const libcDll = "msvcrt.dll"
@@ -37,9 +39,10 @@ else:
   var gExeHandle = loadLib()
 
 proc getDll(conf: ConfigRef, cache: var TDllCache; dll: string; info: TLineInfo): pointer =
+  result = nil
   if dll in cache:
     return cache[dll]
-  var libs: seq[string]
+  var libs: seq[string] = @[]
   libCandidates(dll, libs)
   for c in libs:
     result = loadLib(c)
@@ -61,7 +64,7 @@ proc importcSymbol*(conf: ConfigRef, sym: PSym): PNode =
     let lib = sym.annex
     if lib != nil and lib.path.kind notin {nkStrLit..nkTripleStrLit}:
       globalError(conf, sym.info, "dynlib needs to be a string lit")
-    var theAddr: pointer
+    var theAddr: pointer = nil
     if (lib.isNil or lib.kind == libHeader) and not gExeHandle.isNil:
       libPathMsg = "current exe: " & getAppFilename() & " nor libc: " & libcDll
       # first try this exe itself:
@@ -108,6 +111,7 @@ proc mapCallConv(conf: ConfigRef, cc: TCallingConvention, info: TLineInfo): TABI
   of ccStdCall: result = when defined(windows) and defined(x86): STDCALL else: DEFAULT_ABI
   of ccCDecl: result = DEFAULT_ABI
   else:
+    result = default(TABI)
     globalError(conf, info, "cannot map calling convention to FFI")
 
 template rd(typ, p: untyped): untyped = (cast[ptr typ](p))[]
@@ -132,6 +136,8 @@ 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 +146,7 @@ proc pack(conf: ConfigRef, v: PNode, typ: PType, res: pointer)
 proc getField(conf: ConfigRef, n: PNode; position: int): PSym =
   case n.kind
   of nkRecList:
+    result = nil
     for i in 0..<n.len:
       result = getField(conf, n[i], position)
       if result != nil: return
@@ -154,7 +161,8 @@ proc getField(conf: ConfigRef, n: PNode; position: int): PSym =
       else: internalError(conf, n.info, "getField(record case branch)")
   of nkSym:
     if n.sym.position == position: result = n.sym
-  else: discard
+    else: result = nil
+  else: result = nil
 
 proc packObject(conf: ConfigRef, x: PNode, typ: PType, res: pointer) =
   internalAssert conf, x.kind in {nkObjConstr, nkPar, nkTupleConstr}
@@ -356,6 +364,7 @@ proc unpack(conf: ConfigRef, x: pointer, typ: PType, n: PNode): PNode =
     of 4: awi(nkIntLit, rd(int32, x).BiggestInt)
     of 8: awi(nkIntLit, rd(int64, x).BiggestInt)
     else:
+      result = nil
       globalError(conf, n.info, "cannot map value from FFI (tyEnum, tySet)")
   of tyFloat: awf(nkFloatLit, rd(float, x))
   of tyFloat32: awf(nkFloat32Lit, rd(float32, x))
@@ -381,6 +390,7 @@ 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 +408,7 @@ 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 +435,7 @@ 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 +447,7 @@ 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 +475,7 @@ 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 +489,7 @@ proc callForeignFunction*(conf: ConfigRef, fn: PNode, fntyp: PType,
               mapType(conf, fntyp[0]), sig) != OK:
     globalError(conf, info, "error in FFI call")
 
-  var cargs: ArgList
+  var cargs: ArgList = default(ArgList)
   let fn = cast[pointer](fn.intVal)
   for i in 0..len-1:
     let t = args[i+start].typ

compiler/evaltempl.nim

@@ -9,8 +9,8 @@
 
 ## Template evaluation engine. Now hygienic.
 
-import
-  strutils, options, ast, astalgo, msgs, renderer, lineinfos, idents, trees
+import options, ast, astalgo, msgs, renderer, lineinfos, idents, trees
+import std/strutils
 
 type
   TemplCtx = object
@@ -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/expanddefaults.nim

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

compiler/extccomp.nim

@@ -33,6 +33,7 @@ type
     hasGnuAsm,                # CC's asm uses the absurd GNU assembler syntax
     hasDeclspec,              # CC has __declspec(X)
     hasAttribute,             # CC has __attribute__((X))
+    hasBuiltinUnreachable     # CC has __builtin_unreachable
   TInfoCCProps* = set[TInfoCCProp]
   TInfoCC* = tuple[
     name: string,        # the short name of the compiler
@@ -95,7 +96,7 @@ compiler gcc:
     produceAsm: gnuAsmListing,
     cppXsupport: "-std=gnu++17 -funsigned-char",
     props: {hasSwitchRange, hasComputedGoto, hasCpp, hasGcGuard, hasGnuAsm,
-            hasAttribute})
+            hasAttribute, hasBuiltinUnreachable})
 
 # GNU C and C++ Compiler
 compiler nintendoSwitchGCC:
@@ -122,7 +123,7 @@ compiler nintendoSwitchGCC:
     produceAsm: gnuAsmListing,
     cppXsupport: "-std=gnu++17 -funsigned-char",
     props: {hasSwitchRange, hasComputedGoto, hasCpp, hasGcGuard, hasGnuAsm,
-            hasAttribute})
+            hasAttribute, hasBuiltinUnreachable})
 
 # LLVM Frontend for GCC/G++
 compiler llvmGcc:
@@ -318,7 +319,7 @@ proc getConfigVar(conf: ConfigRef; c: TSystemCC, suffix: string): string =
   var fullSuffix = suffix
   case conf.backend
   of backendCpp, backendJs, backendObjc: fullSuffix = "." & $conf.backend & suffix
-  of backendC: discard
+  of backendC, backendNir: discard
   of backendInvalid:
     # during parsing of cfg files; we don't know the backend yet, no point in
     # guessing wrong thing
@@ -486,6 +487,10 @@ proc vccplatform(conf: ConfigRef): string =
         of cpuArm: " --platform:arm"
         of cpuAmd64: " --platform:amd64"
         else: ""
+    else:
+      result = ""
+  else:
+    result = ""
 
 proc getLinkOptions(conf: ConfigRef): string =
   result = conf.linkOptions & " " & conf.linkOptionsCmd & " "
@@ -534,7 +539,7 @@ proc ccHasSaneOverflow*(conf: ConfigRef): bool =
     # NOTE: should we need the full version, use -dumpfullversion
     let (s, exitCode) = try: execCmdEx(exe & " -dumpversion") except IOError, OSError, ValueError: ("", 1)
     if exitCode == 0:
-      var major: int
+      var major: int = 0
       discard parseInt(s, major)
       result = major >= 5
   else:
@@ -644,7 +649,7 @@ proc externalFileChanged(conf: ConfigRef; cfile: Cfile): bool =
 
   let hashFile = toGeneratedFile(conf, conf.mangleModuleName(cfile.cname).AbsoluteFile, "sha1")
   let currentHash = footprint(conf, cfile)
-  var f: File
+  var f: File = default(File)
   if open(f, hashFile.string, fmRead):
     let oldHash = parseSecureHash(f.readLine())
     close(f)
@@ -779,6 +784,7 @@ template tryExceptOSErrorMessage(conf: ConfigRef; errorPrefix: string = "", body
     raise
 
 proc getExtraCmds(conf: ConfigRef; output: AbsoluteFile): seq[string] =
+  result = @[]
   when defined(macosx):
     if optCDebug in conf.globalOptions and optGenStaticLib notin conf.globalOptions:
       # if needed, add an option to skip or override location
@@ -861,6 +867,7 @@ proc hcrLinkTargetName(conf: ConfigRef, objFile: string, isMain = false): Absolu
   result = conf.getNimcacheDir / RelativeFile(targetName)
 
 proc displayProgressCC(conf: ConfigRef, path, compileCmd: string): string =
+  result = ""
   if conf.hasHint(hintCC):
     if optListCmd in conf.globalOptions or conf.verbosity > 1:
       result = MsgKindToStr[hintCC] % (demangleModuleName(path.splitFile.name) & ": " & compileCmd)
@@ -883,15 +890,15 @@ proc preventLinkCmdMaxCmdLen(conf: ConfigRef, linkCmd: string) =
 
 proc callCCompiler*(conf: ConfigRef) =
   var
-    linkCmd: string
+    linkCmd: string = ""
     extraCmds: seq[string]
   if conf.globalOptions * {optCompileOnly, optGenScript} == {optCompileOnly}:
     return # speed up that call if only compiling and no script shall be
            # generated
   #var c = cCompiler
   var script: Rope = ""
-  var cmds: TStringSeq
-  var prettyCmds: TStringSeq
+  var cmds: TStringSeq = default(TStringSeq)
+  var prettyCmds: TStringSeq = default(TStringSeq)
   let prettyCb = proc (idx: int) = writePrettyCmdsStderr(prettyCmds[idx])
 
   for idx, it in conf.toCompile:
@@ -1022,8 +1029,9 @@ 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
@@ -1039,7 +1047,7 @@ 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()
@@ -1052,7 +1060,8 @@ 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
@@ -1062,6 +1071,7 @@ proc runJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile) =
   for cmd in bcache.extraCmds: execExternalProgram(conf, cmd, hintExecuting)
 
 proc genMappingFiles(conf: ConfigRef; list: CfileList): Rope =
+  result = ""
   for it in list:
     result.addf("--file:r\"$1\"$N", [rope(it.cname.string)])
 

compiler/filter_tmpl.nim

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

compiler/filters.nim

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

compiler/gorgeimpl.nim

@@ -9,8 +9,9 @@
 
 ## Module that implements ``gorge`` for the compiler.
 
-import msgs, os, osproc, streams, options,
-  lineinfos, pathutils
+import msgs, options, lineinfos, pathutils
+
+import std/[os, osproc, streams]
 
 when defined(nimPreviewSlimSystem):
   import std/syncio
@@ -29,10 +30,11 @@ proc readOutput(p: Process): (string, int) =
 
 proc opGorge*(cmd, input, cache: string, info: TLineInfo; conf: ConfigRef): (string, int) =
   let workingDir = parentDir(toFullPath(conf, info))
+  result = ("", 0)
   if cache.len > 0:
     let h = secureHash(cmd & "\t" & input & "\t" & cache)
     let filename = toGeneratedFile(conf, AbsoluteFile("gorge_" & $h), "txt").string
-    var f: File
+    var f: File = default(File)
     if optForceFullMake notin conf.globalOptions and open(f, filename):
       result = (f.readAll, 0)
       f.close

compiler/guards.nim

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

compiler/hlo.nim

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

compiler/ic/bitabs.nim

@@ -1,7 +1,8 @@
 ## A BiTable is a table that can be seen as an optimized pair
 ## of `(Table[LitId, Val], Table[Val, LitId])`.
 
-import hashes, rodfiles
+import std/hashes
+import rodfiles
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -13,6 +14,8 @@ type
     vals: seq[T] # indexed by LitId
     keys: seq[LitId]  # indexed by hash(val)
 
+proc initBiTable*[T](): BiTable[T] = BiTable[T](vals: @[], keys: @[])
+
 proc nextTry(h, maxHash: Hash): Hash {.inline.} =
   result = (h + 1) and maxHash
 
@@ -33,9 +36,7 @@ proc mustRehash(length, counter: int): bool {.inline.} =
   result = (length * 2 < counter * 3) or (length - counter < 4)
 
 const
-  idStart = 256 ##
-  ## Ids do not start with 0 but with this value. The IR needs it.
-  ## TODO: explain why
+  idStart = 1
 
 template idToIdx(x: LitId): int = x.int - idStart
 
@@ -118,6 +119,12 @@ proc load*[T](f: var RodFile; t: var BiTable[T]) =
   loadSeq(f, t.vals)
   loadSeq(f, t.keys)
 
+proc sizeOnDisc*(t: BiTable[string]): int =
+  result = 4
+  for x in t.vals:
+    result += x.len + 4
+  result += t.keys.len * sizeof(LitId)
+
 when isMainModule:
 
   var t: BiTable[string]

compiler/ic/cbackend.nim

@@ -18,7 +18,7 @@
 ## also doing cross-module dependency tracking and DCE that we don't need
 ## anymore. DCE is now done as prepass over the entire packed module graph.
 
-import std/packedsets, algorithm, tables
+import std/[packedsets, algorithm, tables]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -50,10 +50,9 @@ 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)
 
-  let disps = finalCodegenActions(g, bmod, newNodeI(nkStmtList, m.module.info))
-  if disps != nil:
-    for disp in disps:
-      genProcAux(bmod, disp.sym)
+  finalCodegenActions(g, bmod, newNodeI(nkStmtList, m.module.info))
+  for disp in getDispatchers(g):
+    genProcAux(bmod, disp)
   m.fromDisk.backendFlags = cgen.whichInitProcs(bmod)
 
 proc replayTypeInfo(g: ModuleGraph; m: var LoadedModule; origin: FileIndex) =
@@ -101,7 +100,7 @@ proc aliveSymsChanged(config: ConfigRef; position: int; alive: AliveSyms): bool
   var f2 = rodfiles.open(asymFile.string)
   f2.loadHeader()
   f2.loadSection aliveSymsSection
-  var oldData: seq[int32]
+  var oldData: seq[int32] = @[]
   f2.loadSeq(oldData)
   f2.close
   if f2.err == ok and oldData == s:
@@ -147,12 +146,12 @@ proc generateCode*(g: ModuleGraph) =
   var alive = computeAliveSyms(g.packed, g.config)
 
   when false:
-    for i in 0..high(g.packed):
+    for i in 0..<len(g.packed):
       echo i, " is of status ", g.packed[i].status, " ", toFullPath(g.config, FileIndex(i))
 
   # First pass: Setup all the backend modules for all the modules that have
   # changed:
-  for i in 0..high(g.packed):
+  for i in 0..<len(g.packed):
     # case statement here to enforce exhaustive checks.
     case g.packed[i].status
     of undefined:
@@ -174,7 +173,7 @@ proc generateCode*(g: ModuleGraph) =
   let mainModuleIdx = g.config.projectMainIdx2.int
   # We need to generate the main module last, because only then
   # all init procs have been registered:
-  for i in 0..high(g.packed):
+  for i in 0..<len(g.packed):
     if i != mainModuleIdx:
       genPackedModule(g, i, alive)
   if mainModuleIdx >= 0:

compiler/ic/dce.nim

@@ -40,10 +40,14 @@ proc isExportedToC(c: var AliveContext; g: PackedModuleGraph; symId: int32): boo
     if ({sfExportc, sfCompilerProc} * flags != {}) or
         (symPtr.kind == skMethod):
       result = true
+    else:
+      result = false
       # XXX: This used to be a condition to:
       #  (sfExportc in prc.flags and lfExportLib in prc.loc.flags) or
     if sfCompilerProc in flags:
       c.compilerProcs[g[c.thisModule].fromDisk.strings[symPtr.name]] = (c.thisModule, symId)
+  else:
+    result = false
 
 template isNotGeneric(n: NodePos): bool = ithSon(tree, n, genericParamsPos).kind == nkEmpty
 
@@ -105,13 +109,13 @@ proc aliveCode(c: var AliveContext; g: PackedModuleGraph; tree: PackedTree; n: N
     discard "ignore non-sym atoms"
   of nkSym:
     # This symbol is alive and everything its body references.
-    followLater(c, g, c.thisModule, n.operand)
+    followLater(c, g, c.thisModule, tree[n].soperand)
   of nkModuleRef:
     let (n1, n2) = sons2(tree, n)
-    assert n1.kind == nkInt32Lit
-    assert n2.kind == nkInt32Lit
+    assert n1.kind == nkNone
+    assert n2.kind == nkNone
     let m = n1.litId
-    let item = n2.operand
+    let item = tree[n2].soperand
     let otherModule = toFileIndexCached(c.decoder, g, c.thisModule, m).int
     followLater(c, g, otherModule, item)
   of nkMacroDef, nkTemplateDef, nkTypeSection, nkTypeOfExpr,
@@ -127,7 +131,7 @@ proc aliveCode(c: var AliveContext; g: PackedModuleGraph; tree: PackedTree; n: N
     rangeCheckAnalysis(c, g, tree, n)
   of nkProcDef, nkConverterDef, nkMethodDef, nkFuncDef, nkIteratorDef:
     if n.firstSon.kind == nkSym and isNotGeneric(n):
-      let item = n.firstSon.operand
+      let item = tree[n.firstSon].soperand
       if isExportedToC(c, g, item):
         # This symbol is alive and everything its body references.
         followLater(c, g, c.thisModule, item)
@@ -149,7 +153,7 @@ proc computeAliveSyms*(g: PackedModuleGraph; conf: ConfigRef): AliveSyms =
   var c = AliveContext(stack: @[], decoder: PackedDecoder(config: conf),
                        thisModule: -1, alive: newSeq[IntSet](g.len),
                        options: conf.options)
-  for i in countdown(high(g), 0):
+  for i in countdown(len(g)-1, 0):
     if g[i].status != undefined:
       c.thisModule = i
       for p in allNodes(g[i].fromDisk.topLevel):

compiler/ic/ic.nim

@@ -7,15 +7,17 @@
 #    distribution, for details about the copyright.
 #
 
-import hashes, tables, intsets
+import std/[hashes, tables, intsets, monotimes]
 import packed_ast, bitabs, rodfiles
 import ".." / [ast, idents, lineinfos, msgs, ropes, options,
   pathutils, condsyms, packages, modulepaths]
 #import ".." / [renderer, astalgo]
-from os import removeFile, isAbsolute
+from std/os import removeFile, isAbsolute
 
 import ../../dist/checksums/src/checksums/sha1
 
+import ".." / nir / nirlineinfos
+
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions, formatfloat]
 
@@ -41,16 +43,18 @@ type
     bodies*: PackedTree # other trees. Referenced from typ.n and sym.ast by their position.
     #producedGenerics*: Table[GenericKey, SymId]
     exports*: seq[(LitId, int32)]
-    hidden*: seq[(LitId, int32)]
-    reexports*: seq[(LitId, PackedItemId)]
+    hidden: seq[(LitId, int32)]
+    reexports: seq[(LitId, PackedItemId)]
     compilerProcs*: seq[(LitId, int32)]
     converters*, methods*, trmacros*, pureEnums*: seq[int32]
 
     typeInstCache*: seq[(PackedItemId, PackedItemId)]
     procInstCache*: seq[PackedInstantiation]
     attachedOps*: seq[(PackedItemId, TTypeAttachedOp, PackedItemId)]
-    methodsPerType*: seq[(PackedItemId, int, PackedItemId)]
+    methodsPerGenericType*: seq[(PackedItemId, int, PackedItemId)]
     enumToStringProcs*: seq[(PackedItemId, PackedItemId)]
+    methodsPerType*: seq[(PackedItemId, PackedItemId)]
+    dispatchers*: seq[PackedItemId]
 
     emittedTypeInfo*: seq[string]
     backendFlags*: set[ModuleBackendFlag]
@@ -60,6 +64,7 @@ type
     strings*: BiTable[string] # we could share these between modules.
     numbers*: BiTable[BiggestInt] # we also store floats in here so
                                   # that we can assure that every bit is kept
+    man*: LineInfoManager
 
     cfg: PackedConfig
 
@@ -75,37 +80,36 @@ type
     symMarker*: IntSet #Table[ItemId, SymId]    # ItemId.item -> SymId
     config*: ConfigRef
 
-proc toString*(tree: PackedTree; n: NodePos; m: PackedModule; nesting: int;
+proc toString*(tree: PackedTree; pos: NodePos; m: PackedModule; nesting: int;
                result: var string) =
-  let pos = n.int
   if result.len > 0 and result[^1] notin {' ', '\n'}:
     result.add ' '
 
   result.add $tree[pos].kind
-  case tree.nodes[pos].kind
-  of nkNone, nkEmpty, nkNilLit, nkType: discard
+  case tree[pos].kind
+  of nkEmpty, nkNilLit, nkType: discard
   of nkIdent, nkStrLit..nkTripleStrLit:
     result.add " "
-    result.add m.strings[LitId tree.nodes[pos].operand]
+    result.add m.strings[LitId tree[pos].uoperand]
   of nkSym:
     result.add " "
-    result.add m.strings[m.syms[tree.nodes[pos].operand].name]
+    result.add m.strings[m.syms[tree[pos].soperand].name]
   of directIntLit:
     result.add " "
-    result.addInt tree.nodes[pos].operand
+    result.addInt tree[pos].soperand
   of externSIntLit:
     result.add " "
-    result.addInt m.numbers[LitId tree.nodes[pos].operand]
+    result.addInt m.numbers[LitId tree[pos].uoperand]
   of externUIntLit:
     result.add " "
-    result.addInt cast[uint64](m.numbers[LitId tree.nodes[pos].operand])
+    result.addInt cast[uint64](m.numbers[LitId tree[pos].uoperand])
   of nkFloatLit..nkFloat128Lit:
     result.add " "
-    result.addFloat cast[BiggestFloat](m.numbers[LitId tree.nodes[pos].operand])
+    result.addFloat cast[BiggestFloat](m.numbers[LitId tree[pos].uoperand])
   else:
     result.add "(\n"
     for i in 1..(nesting+1)*2: result.add ' '
-    for child in sonsReadonly(tree, n):
+    for child in sonsReadonly(tree, pos):
       toString(tree, child, m, nesting + 1, result)
     result.add "\n"
     for i in 1..nesting*2: result.add ' '
@@ -231,10 +235,14 @@ proc addImportFileDep*(c: var PackedEncoder; m: var PackedModule; f: FileIndex)
   m.imports.add toLitId(f, c, m)
 
 proc addHidden*(c: var PackedEncoder; m: var PackedModule; s: PSym) =
+  assert s.kind != skUnknown
   let nameId = getOrIncl(m.strings, s.name.s)
   m.hidden.add((nameId, s.itemId.item))
+  assert s.itemId.module == c.thisModule
 
 proc addExported*(c: var PackedEncoder; m: var PackedModule; s: PSym) =
+  assert s.kind != skUnknown
+  assert s.itemId.module == c.thisModule
   let nameId = getOrIncl(m.strings, s.name.s)
   m.exports.add((nameId, s.itemId.item))
 
@@ -253,6 +261,8 @@ proc addMethod*(c: var PackedEncoder; m: var PackedModule; s: PSym) =
   m.methods.add s.itemId.item
 
 proc addReexport*(c: var PackedEncoder; m: var PackedModule; s: PSym) =
+  assert s.kind != skUnknown
+  if s.kind == skModule: return
   let nameId = getOrIncl(m.strings, s.name.s)
   m.reexports.add((nameId, PackedItemId(module: toLitId(s.itemId.module.FileIndex, c, m),
                                         item: s.itemId.item)))
@@ -284,7 +294,8 @@ proc toLitId(x: BiggestInt; m: var PackedModule): LitId =
   result = getOrIncl(m.numbers, x)
 
 proc toPackedInfo(x: TLineInfo; c: var PackedEncoder; m: var PackedModule): PackedLineInfo =
-  PackedLineInfo(line: x.line, col: x.col, file: toLitId(x.fileIndex, c, m))
+  pack(m.man, toLitId(x.fileIndex, c, m), x.line.int32, x.col.int32)
+  #PackedLineInfo(line: x.line, col: x.col, file: toLitId(x.fileIndex, c, m))
 
 proc safeItemId(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId {.inline.} =
   ## given a symbol, produce an ItemId with the correct properties
@@ -336,7 +347,7 @@ proc storeTypeLater(t: PType; c: var PackedEncoder; m: var PackedModule): Packed
 proc storeSymLater(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId =
   if s.isNil: return nilItemId
   assert s.itemId.module >= 0
-  assert s.itemId.module >= 0
+  assert s.itemId.item >= 0
   result = PackedItemId(module: toLitId(s.itemId.module.FileIndex, c, m), item: s.itemId.item)
   if s.itemId.module == c.thisModule:
     # the sym belongs to this module, so serialize it here, eventually.
@@ -359,7 +370,7 @@ proc storeType(t: PType; c: var PackedEncoder; m: var PackedModule): PackedItemI
       paddingAtEnd: t.paddingAtEnd)
     storeNode(p, t, n)
     p.typeInst = t.typeInst.storeType(c, m)
-    for kid in items t.sons:
+    for kid in items t:
       p.types.add kid.storeType(c, m)
     c.addMissing t.sym
     p.sym = t.sym.safeItemId(c, m)
@@ -413,6 +424,7 @@ 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
@@ -420,53 +432,59 @@ proc storeSym*(s: PSym; c: var PackedEncoder; m: var PackedModule): PackedItemId
 proc addModuleRef(n: PNode; ir: var PackedTree; c: var PackedEncoder; m: var PackedModule) =
   ## add a remote symbol reference to the tree
   let info = n.info.toPackedInfo(c, m)
-  ir.nodes.add PackedNode(kind: nkModuleRef, operand: 3.int32, # spans 3 nodes in total
-                          typeId: storeTypeLater(n.typ, c, m), info: info)
-  ir.nodes.add PackedNode(kind: nkInt32Lit, info: info,
-                          operand: toLitId(n.sym.itemId.module.FileIndex, c, m).int32)
-  ir.nodes.add PackedNode(kind: nkInt32Lit, info: info,
-                          operand: n.sym.itemId.item)
+  if n.typ != n.sym.typ:
+    ir.addNode(kind = nkModuleRef, operand = 3.int32, # spans 3 nodes in total
+               info = info,
+               typeId = storeTypeLater(n.typ, c, m))
+  else:
+    ir.addNode(kind = nkModuleRef, operand = 3.int32, # spans 3 nodes in total
+              info = info)
+  ir.addNode(kind = nkNone, info = info,
+             operand = toLitId(n.sym.itemId.module.FileIndex, c, m).int32)
+  ir.addNode(kind = nkNone, info = info,
+             operand = n.sym.itemId.item)
 
 proc toPackedNode*(n: PNode; ir: var PackedTree; c: var PackedEncoder; m: var PackedModule) =
   ## serialize a node into the tree
   if n == nil:
-    ir.nodes.add PackedNode(kind: nkNilRodNode, flags: {}, operand: 1)
+    ir.addNode(kind = nkNilRodNode, operand = 1, info = NoLineInfo)
     return
   let info = toPackedInfo(n.info, c, m)
   case n.kind
   of nkNone, nkEmpty, nkNilLit, nkType:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags, operand: 0,
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags, operand = 0,
+               typeId = storeTypeLater(n.typ, c, m), info = info)
   of nkIdent:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32 getOrIncl(m.strings, n.ident.s),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags,
+                operand = int32 getOrIncl(m.strings, n.ident.s),
+                typeId = storeTypeLater(n.typ, c, m), info = info)
   of nkSym:
     if n.sym.itemId.module == c.thisModule:
       # it is a symbol that belongs to the module we're currently
       # packing:
       let id = n.sym.storeSymLater(c, m).item
-      ir.nodes.add PackedNode(kind: nkSym, flags: n.flags, operand: id,
-                              typeId: storeTypeLater(n.typ, c, m), info: info)
+      if n.typ != n.sym.typ:
+        ir.addNode(kind = nkSym, flags = n.flags, operand = id,
+                   info = info,
+                   typeId = storeTypeLater(n.typ, c, m))
+      else:
+        ir.addNode(kind = nkSym, flags = n.flags, operand = id,
+                   info = info)
     else:
       # store it as an external module reference:
       addModuleRef(n, ir, c, m)
-  of directIntLit:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32(n.intVal),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
   of externIntLit:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32 getOrIncl(m.numbers, n.intVal),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags,
+               operand = int32 getOrIncl(m.numbers, n.intVal),
+               typeId = storeTypeLater(n.typ, c, m), info = info)
   of nkStrLit..nkTripleStrLit:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32 getOrIncl(m.strings, n.strVal),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags,
+               operand = int32 getOrIncl(m.strings, n.strVal),
+               typeId = storeTypeLater(n.typ, c, m), info = info)
   of nkFloatLit..nkFloat128Lit:
-    ir.nodes.add PackedNode(kind: n.kind, flags: n.flags,
-                            operand: int32 getOrIncl(m.numbers, cast[BiggestInt](n.floatVal)),
-                            typeId: storeTypeLater(n.typ, c, m), info: info)
+    ir.addNode(kind = n.kind, flags = n.flags,
+               operand = int32 getOrIncl(m.numbers, cast[BiggestInt](n.floatVal)),
+               typeId = storeTypeLater(n.typ, c, m), info = info)
   else:
     let patchPos = ir.prepare(n.kind, n.flags,
                               storeTypeLater(n.typ, c, m), info)
@@ -491,8 +509,8 @@ proc toPackedProcDef(n: PNode; ir: var PackedTree; c: var PackedEncoder; m: var
       # do not serialize the body of the proc, it's unnecessary since
       # n[0].sym.ast has the sem'checked variant of it which is what
       # everybody should use instead.
-      ir.nodes.add PackedNode(kind: nkEmpty, flags: {}, operand: 0,
-                              typeId: nilItemId, info: info)
+      ir.addNode(kind = nkEmpty, flags = {}, operand = 0,
+                 typeId = nilItemId, info = info)
   ir.patch patchPos
 
 proc toPackedNodeIgnoreProcDefs(n: PNode, encoder: var PackedEncoder; m: var PackedModule) =
@@ -565,6 +583,20 @@ proc toRodFile*(conf: ConfigRef; f: AbsoluteFile; ext = RodExt): AbsoluteFile =
   result = changeFileExt(completeGeneratedFilePath(conf,
     mangleModuleName(conf, f).AbsoluteFile), ext)
 
+const
+  BenchIC* = false
+
+when BenchIC:
+  var gloadBodies: MonoTime
+
+  template bench(x, body) =
+    let start = getMonoTime()
+    body
+    x = x + (getMonoTime() - start)
+
+else:
+  template bench(x, body) = body
+
 proc loadRodFile*(filename: AbsoluteFile; m: var PackedModule; config: ConfigRef;
                   ignoreConfig = false): RodFileError =
   var f = rodfiles.open(filename.string)
@@ -589,40 +621,48 @@ proc loadRodFile*(filename: AbsoluteFile; m: var PackedModule; config: ConfigRef
   loadTabSection stringsSection, m.strings
 
   loadSeqSection checkSumsSection, m.includes
-  if not includesIdentical(m, config):
+  if config.cmd != cmdM and not includesIdentical(m, config):
     f.err = includeFileChanged
 
   loadSeqSection depsSection, m.imports
 
-  loadTabSection numbersSection, m.numbers
+  bench gloadBodies:
 
-  loadSeqSection exportsSection, m.exports
-  loadSeqSection hiddenSection, m.hidden
-  loadSeqSection reexportsSection, m.reexports
+    loadTabSection numbersSection, m.numbers
 
-  loadSeqSection compilerProcsSection, m.compilerProcs
+    loadSeqSection exportsSection, m.exports
+    loadSeqSection hiddenSection, m.hidden
+    loadSeqSection reexportsSection, m.reexports
 
-  loadSeqSection trmacrosSection, m.trmacros
+    loadSeqSection compilerProcsSection, m.compilerProcs
 
-  loadSeqSection convertersSection, m.converters
-  loadSeqSection methodsSection, m.methods
-  loadSeqSection pureEnumsSection, m.pureEnums
+    loadSeqSection trmacrosSection, m.trmacros
 
-  loadSeqSection toReplaySection, m.toReplay.nodes
-  loadSeqSection topLevelSection, m.topLevel.nodes
-  loadSeqSection bodiesSection, m.bodies.nodes
-  loadSeqSection symsSection, m.syms
-  loadSeqSection typesSection, m.types
+    loadSeqSection convertersSection, m.converters
+    loadSeqSection methodsSection, m.methods
+    loadSeqSection pureEnumsSection, m.pureEnums
 
-  loadSeqSection typeInstCacheSection, m.typeInstCache
-  loadSeqSection procInstCacheSection, m.procInstCache
-  loadSeqSection attachedOpsSection, m.attachedOps
-  loadSeqSection methodsPerTypeSection, m.methodsPerType
-  loadSeqSection enumToStringProcsSection, m.enumToStringProcs
-  loadSeqSection typeInfoSection, m.emittedTypeInfo
+    loadTabSection toReplaySection, m.toReplay
+    loadTabSection topLevelSection, m.topLevel
 
-  f.loadSection backendFlagsSection
-  f.loadPrim m.backendFlags
+    loadTabSection bodiesSection, m.bodies
+    loadSeqSection symsSection, m.syms
+    loadSeqSection typesSection, m.types
+
+    loadSeqSection typeInstCacheSection, m.typeInstCache
+    loadSeqSection procInstCacheSection, m.procInstCache
+    loadSeqSection attachedOpsSection, m.attachedOps
+    loadSeqSection methodsPerGenericTypeSection, m.methodsPerGenericType
+    loadSeqSection enumToStringProcsSection, m.enumToStringProcs
+    loadSeqSection methodsPerTypeSection, m.methodsPerType
+    loadSeqSection dispatchersSection, m.dispatchers
+    loadSeqSection typeInfoSection, m.emittedTypeInfo
+
+    f.loadSection backendFlagsSection
+    f.loadPrim m.backendFlags
+
+    f.loadSection sideChannelSection
+  f.load m.man
 
   close(f)
   result = f.err
@@ -671,10 +711,10 @@ proc saveRodFile*(filename: AbsoluteFile; encoder: var PackedEncoder; m: var Pac
   storeSeqSection methodsSection, m.methods
   storeSeqSection pureEnumsSection, m.pureEnums
 
-  storeSeqSection toReplaySection, m.toReplay.nodes
-  storeSeqSection topLevelSection, m.topLevel.nodes
+  storeTabSection toReplaySection, m.toReplay
+  storeTabSection topLevelSection, m.topLevel
 
-  storeSeqSection bodiesSection, m.bodies.nodes
+  storeTabSection bodiesSection, m.bodies
   storeSeqSection symsSection, m.syms
 
   storeSeqSection typesSection, m.types
@@ -682,13 +722,18 @@ proc saveRodFile*(filename: AbsoluteFile; encoder: var PackedEncoder; m: var Pac
   storeSeqSection typeInstCacheSection, m.typeInstCache
   storeSeqSection procInstCacheSection, m.procInstCache
   storeSeqSection attachedOpsSection, m.attachedOps
-  storeSeqSection methodsPerTypeSection, m.methodsPerType
+  storeSeqSection methodsPerGenericTypeSection, m.methodsPerGenericType
   storeSeqSection enumToStringProcsSection, m.enumToStringProcs
+  storeSeqSection methodsPerTypeSection, m.methodsPerType
+  storeSeqSection dispatchersSection, m.dispatchers
   storeSeqSection typeInfoSection, m.emittedTypeInfo
 
   f.storeSection backendFlagsSection
   f.storePrim m.backendFlags
 
+  f.storeSection sideChannelSection
+  f.store m.man
+
   close(f)
   encoder.disable()
   if f.err != ok:
@@ -730,13 +775,29 @@ type
       # PackedItemId so that it works with reexported symbols too
       # ifaceHidden includes private symbols
 
-  PackedModuleGraph* = seq[LoadedModule] # indexed by FileIndex
+type
+  PackedModuleGraph* = object
+    pm*: seq[LoadedModule] # indexed by FileIndex
+    when BenchIC:
+      depAnalysis: MonoTime
+      loadBody: MonoTime
+      loadSym, loadType, loadBodies: MonoTime
+
+when BenchIC:
+  proc echoTimes*(m: PackedModuleGraph) =
+    echo "analysis: ", m.depAnalysis, " loadBody: ", m.loadBody, " loadSym: ",
+      m.loadSym, " loadType: ", m.loadType, " all bodies: ", gloadBodies
+
+template `[]`*(m: PackedModuleGraph; i: int): LoadedModule = m.pm[i]
+template len*(m: PackedModuleGraph): int = m.pm.len
 
 proc loadType(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; t: PackedItemId): PType
 proc loadSym(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; s: PackedItemId): PSym
 
 proc toFileIndexCached*(c: var PackedDecoder; g: PackedModuleGraph; thisModule: int; f: LitId): FileIndex =
-  if c.lastLit == f and c.lastModule == thisModule:
+  if f == LitId(0):
+    result = InvalidFileIdx
+  elif c.lastLit == f and c.lastModule == thisModule:
     result = c.lastFile
   else:
     result = toFileIndex(f, g[thisModule].fromDisk, c.config)
@@ -747,8 +808,9 @@ proc toFileIndexCached*(c: var PackedDecoder; g: PackedModuleGraph; thisModule:
 proc translateLineInfo(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
                        x: PackedLineInfo): TLineInfo =
   assert g[thisModule].status in {loaded, storing, stored}
-  result = TLineInfo(line: x.line, col: x.col,
-            fileIndex: toFileIndexCached(c, g, thisModule, x.file))
+  let (fileId, line, col) = unpack(g[thisModule].fromDisk.man, x)
+  result = TLineInfo(line: line.uint16, col: col.int16,
+            fileIndex: toFileIndexCached(c, g, thisModule, fileId))
 
 proc loadNodes*(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
                 tree: PackedTree; n: NodePos): PNode =
@@ -762,14 +824,13 @@ proc loadNodes*(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
   result.flags = n.flags
 
   case k
-  of nkEmpty, nkNilLit, nkType:
+  of nkNone, nkEmpty, nkNilLit, nkType:
     discard
   of nkIdent:
     result.ident = getIdent(c.cache, g[thisModule].fromDisk.strings[n.litId])
   of nkSym:
-    result.sym = loadSym(c, g, thisModule, PackedItemId(module: LitId(0), item: tree.nodes[n.int].operand))
-  of directIntLit:
-    result.intVal = tree.nodes[n.int].operand
+    result.sym = loadSym(c, g, thisModule, PackedItemId(module: LitId(0), item: tree[n].soperand))
+    if result.typ == nil: result.typ = result.sym.typ
   of externIntLit:
     result.intVal = g[thisModule].fromDisk.numbers[n.litId]
   of nkStrLit..nkTripleStrLit:
@@ -778,10 +839,11 @@ proc loadNodes*(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int;
     result.floatVal = cast[BiggestFloat](g[thisModule].fromDisk.numbers[n.litId])
   of nkModuleRef:
     let (n1, n2) = sons2(tree, n)
-    assert n1.kind == nkInt32Lit
-    assert n2.kind == nkInt32Lit
+    assert n1.kind == nkNone
+    assert n2.kind == nkNone
     transitionNoneToSym(result)
-    result.sym = loadSym(c, g, thisModule, PackedItemId(module: n1.litId, item: tree.nodes[n2.int].operand))
+    result.sym = loadSym(c, g, thisModule, PackedItemId(module: n1.litId, item: tree[n2].soperand))
+    if result.typ == nil: result.typ = result.sym.typ
   else:
     for n0 in sonsReadonly(tree, n):
       result.addAllowNil loadNodes(c, g, thisModule, tree, n0)
@@ -813,6 +875,7 @@ 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:
@@ -875,12 +938,27 @@ proc symBodyFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
   if externalName != "":
     result.loc.r = rope externalName
   result.loc.flags = s.locFlags
+  result.instantiatedFrom = loadSym(c, g, si, s.instantiatedFrom)
+
+proc needsRecompile(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
+                    fileIdx: FileIndex; cachedModules: var seq[FileIndex]): bool
+proc loadToReplayNodes(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
+                       fileIdx: FileIndex; m: var LoadedModule)
 
 proc loadSym(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; s: PackedItemId): PSym =
   if s == nilItemId:
     result = nil
   else:
     let si = moduleIndex(c, g, thisModule, s)
+    if si >= g.len:
+      g.pm.setLen(si+1)
+
+    if g[si].status == undefined and c.config.cmd == cmdM:
+      var cachedModules: seq[FileIndex] = @[]
+      discard needsRecompile(g, c.config, c.cache, FileIndex(si), cachedModules)
+      for m in cachedModules:
+        loadToReplayNodes(g, c.config, c.cache, m, g[int m])
+
     assert g[si].status in {loaded, storing, stored}
     if not g[si].symsInit:
       g[si].symsInit = true
@@ -895,6 +973,7 @@ proc loadSym(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; s:
       else:
         result = g[si].module
         assert result != nil
+        g[si].syms[s.item] = result
 
     else:
       result = g[si].syms[s.item]
@@ -915,8 +994,10 @@ proc typeBodyFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
     for op, item in pairs t.attachedOps:
       result.attachedOps[op] = loadSym(c, g, si, item)
   result.typeInst = loadType(c, g, si, t.typeInst)
+  var sons = newSeq[PType]()
   for son in items t.types:
-    result.sons.add loadType(c, g, si, son)
+    sons.add loadType(c, g, si, son)
+  result.setSons(sons)
   loadAstBody(t, n)
   when false:
     for gen, id in items t.methods:
@@ -939,9 +1020,11 @@ proc loadType(c: var PackedDecoder; g: var PackedModuleGraph; thisModule: int; t
       # store it here early on, so that recursions work properly:
       g[si].types[t.item] = result
       typeBodyFromPacked(c, g, g[si].fromDisk.types[t.item], si, t.item, result)
+      #assert result.itemId.item == t.item, $(result.itemId.item, t.item)
+      assert result.itemId.item > 0, $(result.itemId.item, t.item)
     else:
       result = g[si].types[t.item]
-    assert result.itemId.item > 0
+      assert result.itemId.item > 0, "2"
 
 proc setupLookupTables(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
                        fileIdx: FileIndex; m: var LoadedModule) =
@@ -991,30 +1074,37 @@ proc needsRecompile(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache
   # Does the file belong to the fileIdx need to be recompiled?
   let m = int(fileIdx)
   if m >= g.len:
-    g.setLen(m+1)
+    g.pm.setLen(m+1)
 
   case g[m].status
   of undefined:
     g[m].status = loading
     let fullpath = msgs.toFullPath(conf, fileIdx)
     let rod = toRodFile(conf, AbsoluteFile fullpath)
-    let err = loadRodFile(rod, g[m].fromDisk, conf)
+    let err = loadRodFile(rod, g[m].fromDisk, conf, ignoreConfig = conf.cmd == cmdM)
     if err == ok:
-      result = optForceFullMake in conf.globalOptions
-      # check its dependencies:
-      for dep in g[m].fromDisk.imports:
-        let fid = toFileIndex(dep, g[m].fromDisk, conf)
-        # Warning: we need to traverse the full graph, so
-        # do **not use break here**!
-        if needsRecompile(g, conf, cache, fid, cachedModules):
-          result = true
-
-      if not result:
+      if conf.cmd == cmdM:
         setupLookupTables(g, conf, cache, fileIdx, g[m])
         cachedModules.add fileIdx
         g[m].status = loaded
+        result = false
       else:
-        g[m] = LoadedModule(status: outdated, module: g[m].module)
+        result = optForceFullMake in conf.globalOptions
+        # check its dependencies:
+        let imp = g[m].fromDisk.imports
+        for dep in imp:
+          let fid = toFileIndex(dep, g[m].fromDisk, conf)
+          # Warning: we need to traverse the full graph, so
+          # do **not use break here**!
+          if needsRecompile(g, conf, cache, fid, cachedModules):
+            result = true
+
+        if not result:
+          setupLookupTables(g, conf, cache, fileIdx, g[m])
+          cachedModules.add fileIdx
+          g[m].status = loaded
+        else:
+          g.pm[m] = LoadedModule(status: outdated, module: g[m].module)
     else:
       loadError(err, rod, conf)
       g[m].status = outdated
@@ -1029,12 +1119,13 @@ proc needsRecompile(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache
 proc moduleFromRodFile*(g: var PackedModuleGraph; conf: ConfigRef; cache: IdentCache;
                         fileIdx: FileIndex; cachedModules: var seq[FileIndex]): PSym =
   ## Returns 'nil' if the module needs to be recompiled.
-  if needsRecompile(g, conf, cache, fileIdx, cachedModules):
-    result = nil
-  else:
-    result = g[int fileIdx].module
-    assert result != nil
-    assert result.position == int(fileIdx)
+  bench g.depAnalysis:
+    if needsRecompile(g, conf, cache, fileIdx, cachedModules):
+      result = nil
+    else:
+      result = g[int fileIdx].module
+      assert result != nil
+      assert result.position == int(fileIdx)
   for m in cachedModules:
     loadToReplayNodes(g, conf, cache, m, g[int m])
 
@@ -1048,46 +1139,49 @@ template setupDecoder() {.dirty.} =
 
 proc loadProcBody*(config: ConfigRef, cache: IdentCache;
                    g: var PackedModuleGraph; s: PSym): PNode =
-  let mId = s.itemId.module
-  var decoder = PackedDecoder(
-    lastModule: int32(-1),
-    lastLit: LitId(0),
-    lastFile: FileIndex(-1),
-    config: config,
-    cache: cache)
-  let pos = g[mId].fromDisk.syms[s.itemId.item].ast
-  assert pos != emptyNodeId
-  result = loadProcBody(decoder, g, mId, g[mId].fromDisk.bodies, NodePos pos)
+  bench g.loadBody:
+    let mId = s.itemId.module
+    var decoder = PackedDecoder(
+      lastModule: int32(-1),
+      lastLit: LitId(0),
+      lastFile: FileIndex(-1),
+      config: config,
+      cache: cache)
+    let pos = g[mId].fromDisk.syms[s.itemId.item].ast
+    assert pos != emptyNodeId
+    result = loadProcBody(decoder, g, mId, g[mId].fromDisk.bodies, NodePos pos)
 
 proc loadTypeFromId*(config: ConfigRef, cache: IdentCache;
                      g: var PackedModuleGraph; module: int; id: PackedItemId): PType =
-  if id.item < g[module].types.len:
-    result = g[module].types[id.item]
-  else:
-    result = nil
-  if result == nil:
-    var decoder = PackedDecoder(
-      lastModule: int32(-1),
-      lastLit: LitId(0),
-      lastFile: FileIndex(-1),
-      config: config,
-      cache: cache)
-    result = loadType(decoder, g, module, id)
+  bench g.loadType:
+    if id.item < g[module].types.len:
+      result = g[module].types[id.item]
+    else:
+      result = nil
+    if result == nil:
+      var decoder = PackedDecoder(
+        lastModule: int32(-1),
+        lastLit: LitId(0),
+        lastFile: FileIndex(-1),
+        config: config,
+        cache: cache)
+      result = loadType(decoder, g, module, id)
 
 proc loadSymFromId*(config: ConfigRef, cache: IdentCache;
                     g: var PackedModuleGraph; module: int; id: PackedItemId): PSym =
-  if id.item < g[module].syms.len:
-    result = g[module].syms[id.item]
-  else:
-    result = nil
-  if result == nil:
-    var decoder = PackedDecoder(
-      lastModule: int32(-1),
-      lastLit: LitId(0),
-      lastFile: FileIndex(-1),
-      config: config,
-      cache: cache)
-    result = loadSym(decoder, g, module, id)
+  bench g.loadSym:
+    if id.item < g[module].syms.len:
+      result = g[module].syms[id.item]
+    else:
+      result = nil
+    if result == nil:
+      var decoder = PackedDecoder(
+        lastModule: int32(-1),
+        lastLit: LitId(0),
+        lastFile: FileIndex(-1),
+        config: config,
+        cache: cache)
+      result = loadSym(decoder, g, module, id)
 
 proc translateId*(id: PackedItemId; g: PackedModuleGraph; thisModule: int; config: ConfigRef): ItemId =
   if id.module == LitId(0):
@@ -1147,9 +1241,11 @@ proc initRodIter*(it: var RodIter; config: ConfigRef, cache: IdentCache;
   if it.i < it.values.len:
     result = loadSym(it.decoder, g, int(module), it.values[it.i])
     inc it.i
+  else:
+    result = nil
 
 proc initRodIterAllSyms*(it: var RodIter; config: ConfigRef, cache: IdentCache;
-                         g: var PackedModuleGraph; module: FileIndex, importHidden: bool): PSym =
+                         g: var PackedModuleGraph; module: FileIndex; importHidden: bool): PSym =
   it.decoder = PackedDecoder(
     lastModule: int32(-1),
     lastLit: LitId(0),
@@ -1164,11 +1260,15 @@ 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;
@@ -1201,12 +1301,12 @@ proc searchForCompilerproc*(m: LoadedModule; name: string): int32 =
 # ------------------------- .rod file viewer ---------------------------------
 
 proc rodViewer*(rodfile: AbsoluteFile; config: ConfigRef, cache: IdentCache) =
-  var m: PackedModule
+  var m: PackedModule = PackedModule()
   let err = loadRodFile(rodfile, m, config, ignoreConfig=true)
   if err != ok:
     config.quitOrRaise "Error: could not load: " & $rodfile.string & " reason: " & $err
 
-  when true:
+  when false:
     echo "exports:"
     for ex in m.exports:
       echo "  ", m.strings[ex[0]], " local ID: ", ex[1]
@@ -1222,13 +1322,32 @@ proc rodViewer*(rodfile: AbsoluteFile; config: ConfigRef, cache: IdentCache) =
     for ex in m.hidden:
       echo "  ", m.strings[ex[0]], " local ID: ", ex[1]
 
-  echo "all symbols"
-  for i in 0..high(m.syms):
-    if m.syms[i].name != LitId(0):
-      echo "  ", m.strings[m.syms[i].name], " local ID: ", i, " kind ", m.syms[i].kind
-    else:
-      echo "  <anon symbol?> local ID: ", i, " kind ", m.syms[i].kind
+  when false:
+    echo "all symbols"
+    for i in 0..high(m.syms):
+      if m.syms[i].name != LitId(0):
+        echo "  ", m.strings[m.syms[i].name], " local ID: ", i, " kind ", m.syms[i].kind
+      else:
+        echo "  <anon symbol?> local ID: ", i, " kind ", m.syms[i].kind
 
   echo "symbols: ", m.syms.len, " types: ", m.types.len,
-    " top level nodes: ", m.topLevel.nodes.len, " other nodes: ", m.bodies.nodes.len,
+    " top level nodes: ", m.topLevel.len, " other nodes: ", m.bodies.len,
     " strings: ", m.strings.len, " numbers: ", m.numbers.len
+
+  echo "SIZES:"
+  echo "symbols: ", m.syms.len * sizeof(PackedSym), " types: ", m.types.len * sizeof(PackedType),
+    " top level nodes: ", m.topLevel.len * sizeof(PackedNode),
+    " other nodes: ", m.bodies.len * sizeof(PackedNode),
+    " strings: ", sizeOnDisc(m.strings)
+  when false:
+    var tt = 0
+    var fc = 0
+    for x in m.topLevel:
+      if x.kind == nkSym or x.typeId == nilItemId: inc tt
+      if x.flags == {}: inc fc
+    for x in m.bodies:
+      if x.kind == nkSym or x.typeId == nilItemId: inc tt
+      if x.flags == {}: inc fc
+    let total = float(m.topLevel.len + m.bodies.len)
+    echo "nodes with nil type: ", tt, " in % ", tt.float / total
+    echo "nodes with empty flags: ", fc.float / total

compiler/ic/integrity.nim

@@ -10,7 +10,7 @@
 ## Integrity checking for a set of .rod files.
 ## The set must cover a complete Nim project.
 
-import sets
+import std/sets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -72,15 +72,16 @@ proc checkForeignSym(c: var CheckedContext; symId: PackedItemId) =
     c.thisModule = oldThisModule
 
 proc checkNode(c: var CheckedContext; tree: PackedTree; n: NodePos) =
-  if tree[n.int].typeId != nilItemId:
-    checkType(c, tree[n.int].typeId)
+  let t = findType(tree, n)
+  if t != nilItemId:
+    checkType(c, t)
   case n.kind
   of nkEmpty, nkNilLit, nkType, nkNilRodNode:
     discard
   of nkIdent:
     assert c.g.packed[c.thisModule].fromDisk.strings.hasLitId n.litId
   of nkSym:
-    checkLocalSym(c, tree.nodes[n.int].operand)
+    checkLocalSym(c, tree[n].soperand)
   of directIntLit:
     discard
   of externIntLit, nkFloatLit..nkFloat128Lit:
@@ -89,9 +90,9 @@ proc checkNode(c: var CheckedContext; tree: PackedTree; n: NodePos) =
     assert c.g.packed[c.thisModule].fromDisk.strings.hasLitId n.litId
   of nkModuleRef:
     let (n1, n2) = sons2(tree, n)
-    assert n1.kind == nkInt32Lit
-    assert n2.kind == nkInt32Lit
-    checkForeignSym(c, PackedItemId(module: n1.litId, item: tree.nodes[n2.int].operand))
+    assert n1.kind == nkNone
+    assert n2.kind == nkNone
+    checkForeignSym(c, PackedItemId(module: n1.litId, item: tree[n2].soperand))
   else:
     for n0 in sonsReadonly(tree, n):
       checkNode(c, tree, n0)
@@ -134,13 +135,15 @@ proc checkModule(c: var CheckedContext; m: PackedModule) =
     typeInstCache*: seq[(PackedItemId, PackedItemId)]
     procInstCache*: seq[PackedInstantiation]
     attachedOps*: seq[(TTypeAttachedOp, PackedItemId, PackedItemId)]
-    methodsPerType*: seq[(PackedItemId, int, PackedItemId)]
+    methodsPerGenericType*: seq[(PackedItemId, int, PackedItemId)]
     enumToStringProcs*: seq[(PackedItemId, PackedItemId)]
+    methodsPerType*: seq[(PackedItemId, PackedItemId)]
+    dispatchers*: seq[PackedItemId]
   ]#
 
 proc checkIntegrity*(g: ModuleGraph) =
   var c = CheckedContext(g: g)
-  for i in 0..high(g.packed):
+  for i in 0..<len(g.packed):
     # case statement here to enforce exhaustive checks.
     case g.packed[i].status
     of undefined:
@@ -150,4 +153,3 @@ proc checkIntegrity*(g: ModuleGraph) =
     of stored, storing, outdated, loaded:
       c.thisModule = int32 i
       checkModule(c, g.packed[i].fromDisk)
-

compiler/ic/navigator.nim

@@ -11,59 +11,70 @@
 ## IDE-like features. It uses the set of .rod files to accomplish
 ## its task. The set must cover a complete Nim project.
 
-import sets
+import std/sets
 
-from os import nil
+from std/os import nil
 from std/private/miscdollars import toLocation
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
 import ".." / [ast, modulegraphs, msgs, options]
+import ".." / nir / nirlineinfos
 import packed_ast, bitabs, ic
 
 type
+  UnpackedLineInfo = object
+    file: LitId
+    line, col: int
   NavContext = object
     g: ModuleGraph
     thisModule: int32
-    trackPos: PackedLineInfo
+    trackPos: UnpackedLineInfo
     alreadyEmitted: HashSet[string]
     outputSep: char # for easier testing, use short filenames and spaces instead of tabs.
 
-proc isTracked(current, trackPos: PackedLineInfo, tokenLen: int): bool =
-  if current.file == trackPos.file and current.line == trackPos.line:
+proc isTracked(man: LineInfoManager; current: PackedLineInfo, trackPos: UnpackedLineInfo, tokenLen: int): bool =
+  let (currentFile, currentLine, currentCol) = man.unpack(current)
+  if currentFile == trackPos.file and currentLine == trackPos.line:
     let col = trackPos.col
-    if col >= current.col and col < current.col+tokenLen:
-      return true
+    if col >= currentCol and col < currentCol+tokenLen:
+      result = true
+    else:
+      result = false
+  else:
+    result = false
 
 proc searchLocalSym(c: var NavContext; s: PackedSym; info: PackedLineInfo): bool =
   result = s.name != LitId(0) and
-    isTracked(info, c.trackPos, c.g.packed[c.thisModule].fromDisk.strings[s.name].len)
+    isTracked(c.g.packed[c.thisModule].fromDisk.man, info, c.trackPos, c.g.packed[c.thisModule].fromDisk.strings[s.name].len)
 
 proc searchForeignSym(c: var NavContext; s: ItemId; info: PackedLineInfo): bool =
   let name = c.g.packed[s.module].fromDisk.syms[s.item].name
   result = name != LitId(0) and
-    isTracked(info, c.trackPos, c.g.packed[s.module].fromDisk.strings[name].len)
+    isTracked(c.g.packed[c.thisModule].fromDisk.man, info, c.trackPos, c.g.packed[s.module].fromDisk.strings[name].len)
 
 const
   EmptyItemId = ItemId(module: -1'i32, item: -1'i32)
 
 proc search(c: var NavContext; tree: PackedTree): ItemId =
   # We use the linear representation here directly:
-  for i in 0..high(tree.nodes):
-    case tree.nodes[i].kind
+  for i in 0..<len(tree):
+    let i = NodePos(i)
+    case tree[i].kind
     of nkSym:
-      let item = tree.nodes[i].operand
-      if searchLocalSym(c, c.g.packed[c.thisModule].fromDisk.syms[item], tree.nodes[i].info):
+      let item = tree[i].soperand
+      if searchLocalSym(c, c.g.packed[c.thisModule].fromDisk.syms[item], tree[i].info):
         return ItemId(module: c.thisModule, item: item)
     of nkModuleRef:
-      if tree.nodes[i].info.line == c.trackPos.line and tree.nodes[i].info.file == c.trackPos.file:
-        let (n1, n2) = sons2(tree, NodePos i)
+      let (currentFile, currentLine, currentCol) = c.g.packed[c.thisModule].fromDisk.man.unpack(tree[i].info)
+      if currentLine == c.trackPos.line and currentFile == c.trackPos.file:
+        let (n1, n2) = sons2(tree, i)
         assert n1.kind == nkInt32Lit
         assert n2.kind == nkInt32Lit
-        let pId = PackedItemId(module: n1.litId, item: tree.nodes[n2.int].operand)
+        let pId = PackedItemId(module: n1.litId, item: tree[n2].soperand)
         let itemId = translateId(pId, c.g.packed, c.thisModule, c.g.config)
-        if searchForeignSym(c, itemId, tree.nodes[i].info):
+        if searchForeignSym(c, itemId, tree[i].info):
           return itemId
     else: discard
   return EmptyItemId
@@ -73,36 +84,38 @@ proc isDecl(tree: PackedTree; n: NodePos): bool =
   const declarativeNodes = procDefs + {nkMacroDef, nkTemplateDef,
     nkLetSection, nkVarSection, nkUsingStmt, nkConstSection, nkTypeSection,
     nkIdentDefs, nkEnumTy, nkVarTuple}
-  result = n.int >= 0 and tree[n.int].kind in declarativeNodes
+  result = n.int >= 0 and tree[n].kind in declarativeNodes
 
 proc usage(c: var NavContext; info: PackedLineInfo; isDecl: bool) =
+  let (fileId, line, col) = unpack(c.g.packed[c.thisModule].fromDisk.man, info)
   var m = ""
-  var file = c.g.packed[c.thisModule].fromDisk.strings[info.file]
+  var file = c.g.packed[c.thisModule].fromDisk.strings[fileId]
   if c.outputSep == ' ':
     file = os.extractFilename file
-  toLocation(m, file, info.line.int, info.col.int + ColOffset)
+  toLocation(m, file, line, col + ColOffset)
   if not c.alreadyEmitted.containsOrIncl(m):
     msgWriteln c.g.config, (if isDecl: "def" else: "usage") & c.outputSep & m
 
 proc list(c: var NavContext; tree: PackedTree; sym: ItemId) =
-  for i in 0..high(tree.nodes):
-    case tree.nodes[i].kind
+  for i in 0..<len(tree):
+    let i = NodePos(i)
+    case tree[i].kind
     of nkSym:
-      let item = tree.nodes[i].operand
+      let item = tree[i].soperand
       if sym.item == item and sym.module == c.thisModule:
-        usage(c, tree.nodes[i].info, isDecl(tree, parent(NodePos i)))
+        usage(c, tree[i].info, isDecl(tree, parent(i)))
     of nkModuleRef:
-      let (n1, n2) = sons2(tree, NodePos i)
-      assert n1.kind == nkInt32Lit
-      assert n2.kind == nkInt32Lit
-      let pId = PackedItemId(module: n1.litId, item: tree.nodes[n2.int].operand)
+      let (n1, n2) = sons2(tree, i)
+      assert n1.kind == nkNone
+      assert n2.kind == nkNone
+      let pId = PackedItemId(module: n1.litId, item: tree[n2].soperand)
       let itemId = translateId(pId, c.g.packed, c.thisModule, c.g.config)
       if itemId.item == sym.item and sym.module == itemId.module:
-        usage(c, tree.nodes[i].info, isDecl(tree, parent(NodePos i)))
+        usage(c, tree[i].info, isDecl(tree, parent(i)))
     else: discard
 
 proc searchForIncludeFile(g: ModuleGraph; fullPath: string): int =
-  for i in 0..high(g.packed):
+  for i in 0..<len(g.packed):
     for k in 1..high(g.packed[i].fromDisk.includes):
       # we start from 1 because the first "include" file is
       # the module's filename.
@@ -134,7 +147,7 @@ proc nav(g: ModuleGraph) =
   var c = NavContext(
     g: g,
     thisModule: int32 mid,
-    trackPos: PackedLineInfo(line: unpacked.line, col: unpacked.col, file: fileId),
+    trackPos: UnpackedLineInfo(line: unpacked.line.int, col: unpacked.col.int, file: fileId),
     outputSep: if isDefined(g.config, "nimIcNavigatorTests"): ' ' else: '\t'
   )
   var symId = search(c, g.packed[mid].fromDisk.topLevel)
@@ -145,7 +158,7 @@ proc nav(g: ModuleGraph) =
     localError(g.config, unpacked, "no symbol at this position")
     return
 
-  for i in 0..high(g.packed):
+  for i in 0..<len(g.packed):
     # case statement here to enforce exhaustive checks.
     case g.packed[i].status
     of undefined:
@@ -162,7 +175,7 @@ proc navUsages*(g: ModuleGraph) = nav(g)
 proc navDefusages*(g: ModuleGraph) = nav(g)
 
 proc writeRodFiles*(g: ModuleGraph) =
-  for i in 0..high(g.packed):
+  for i in 0..<len(g.packed):
     case g.packed[i].status
     of undefined, loading, stored, loaded:
       discard "nothing to do"

compiler/ic/packed_ast.nim

@@ -12,10 +12,12 @@
 ## use this representation directly in all the transformations,
 ## it is superior.
 
-import hashes, tables, strtabs
-import bitabs
+import std/[hashes, tables, strtabs]
+import bitabs, rodfiles
 import ".." / [ast, options]
 
+import ".." / nir / nirlineinfos
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -31,17 +33,12 @@ type
     item*: int32         # same as the in-memory representation
 
 const
-  nilItemId* = PackedItemId(module: LitId(0), item: -1.int32)
+  nilItemId* = PackedItemId(module: LitId(0), item: 0.int32)
 
 const
   emptyNodeId* = NodeId(-1)
 
 type
-  PackedLineInfo* = object
-    line*: uint16
-    col*: int16
-    file*: LitId
-
   PackedLib* = object
     kind*: TLibKind
     generated*: bool
@@ -71,6 +68,7 @@ type
     when hasFFI:
       cname*: LitId
     constraint*: NodeId
+    instantiatedFrom*: PackedItemId
 
   PackedType* = object
     kind*: TTypeKind
@@ -89,23 +87,35 @@ type
     typeInst*: PackedItemId
     nonUniqueId*: int32
 
-  PackedNode* = object     # 28 bytes
-    kind*: TNodeKind
-    flags*: TNodeFlags
-    operand*: int32  # for kind in {nkSym, nkSymDef}: SymId
-                     # for kind in {nkStrLit, nkIdent, nkNumberLit}: LitId
-                     # for kind in nkInt32Lit: direct value
-                     # for non-atom kinds: the number of nodes (for easy skipping)
-    typeId*: PackedItemId
+  PackedNode* = object     # 8 bytes
+    x: uint32
     info*: PackedLineInfo
 
   PackedTree* = object ## usually represents a full Nim module
-    nodes*: seq[PackedNode]
+    nodes: seq[PackedNode]
+    withFlags: seq[(int32, TNodeFlags)]
+    withTypes: seq[(int32, PackedItemId)]
 
   PackedInstantiation* = object
     key*, sym*: PackedItemId
     concreteTypes*: seq[PackedItemId]
 
+const
+  NodeKindBits = 8'u32
+  NodeKindMask = (1'u32 shl NodeKindBits) - 1'u32
+
+template kind*(n: PackedNode): TNodeKind = TNodeKind(n.x and NodeKindMask)
+template uoperand*(n: PackedNode): uint32 = (n.x shr NodeKindBits)
+template soperand*(n: PackedNode): int32 = int32(uoperand(n))
+
+template toX(k: TNodeKind; operand: uint32): uint32 =
+  uint32(k) or (operand shl NodeKindBits)
+
+template toX(k: TNodeKind; operand: LitId): uint32 =
+  uint32(k) or (operand.uint32 shl NodeKindBits)
+
+template typeId*(n: PackedNode): PackedItemId = n.typ
+
 proc `==`*(a, b: SymId): bool {.borrow.}
 proc hash*(a: SymId): Hash {.borrow.}
 
@@ -117,68 +127,32 @@ proc newTreeFrom*(old: PackedTree): PackedTree =
   result.nodes = @[]
   when false: result.sh = old.sh
 
-when false:
-  proc declareSym*(tree: var PackedTree; kind: TSymKind;
-                  name: LitId; info: PackedLineInfo): SymId =
-    result = SymId(tree.sh.syms.len)
-    tree.sh.syms.add PackedSym(kind: kind, name: name, flags: {}, magic: mNone, info: info)
-
-  proc litIdFromName*(tree: PackedTree; name: string): LitId =
-    result = tree.sh.strings.getOrIncl(name)
-
-  proc add*(tree: var PackedTree; kind: TNodeKind; token: string; info: PackedLineInfo) =
-    tree.nodes.add PackedNode(kind: kind, info: info,
-                              operand: int32 getOrIncl(tree.sh.strings, token))
-
-  proc add*(tree: var PackedTree; kind: TNodeKind; info: PackedLineInfo) =
-    tree.nodes.add PackedNode(kind: kind, operand: 0, info: info)
-
-proc throwAwayLastNode*(tree: var PackedTree) =
-  tree.nodes.setLen(tree.nodes.len-1)
-
 proc addIdent*(tree: var PackedTree; s: LitId; info: PackedLineInfo) =
-  tree.nodes.add PackedNode(kind: nkIdent, operand: int32(s), info: info)
+  tree.nodes.add PackedNode(x: toX(nkIdent, uint32(s)), info: info)
 
 proc addSym*(tree: var PackedTree; s: int32; info: PackedLineInfo) =
-  tree.nodes.add PackedNode(kind: nkSym, operand: s, info: info)
-
-proc addModuleId*(tree: var PackedTree; s: ModuleId; info: PackedLineInfo) =
-  tree.nodes.add PackedNode(kind: nkInt32Lit, operand: int32(s), info: info)
+  tree.nodes.add PackedNode(x: toX(nkSym, cast[uint32](s)), info: info)
 
 proc addSymDef*(tree: var PackedTree; s: SymId; info: PackedLineInfo) =
-  tree.nodes.add PackedNode(kind: nkSym, operand: int32(s), info: info)
+  tree.nodes.add PackedNode(x: toX(nkSym, cast[uint32](s)), info: info)
 
 proc isAtom*(tree: PackedTree; pos: int): bool {.inline.} = tree.nodes[pos].kind <= nkNilLit
 
-proc copyTree*(dest: var PackedTree; tree: PackedTree; n: NodePos) =
-  # and this is why the IR is superior. We can copy subtrees
-  # via a linear scan.
-  let pos = n.int
-  let L = if isAtom(tree, pos): 1 else: tree.nodes[pos].operand
-  let d = dest.nodes.len
-  dest.nodes.setLen(d + L)
-  for i in 0..<L:
-    dest.nodes[d+i] = tree.nodes[pos+i]
-
-when false:
-  proc copySym*(dest: var PackedTree; tree: PackedTree; s: SymId): SymId =
-    result = SymId(dest.sh.syms.len)
-    assert int(s) < tree.sh.syms.len
-    let oldSym = tree.sh.syms[s.int]
-    dest.sh.syms.add oldSym
-
 type
   PatchPos = distinct int
 
-when false:
-  proc prepare*(tree: var PackedTree; kind: TNodeKind; info: PackedLineInfo): PatchPos =
-    result = PatchPos tree.nodes.len
-    tree.nodes.add PackedNode(kind: kind, operand: 0, info: info)
+proc addNode*(t: var PackedTree; kind: TNodeKind; operand: int32;
+              typeId: PackedItemId = nilItemId; info: PackedLineInfo;
+              flags: TNodeFlags = {}) =
+  t.nodes.add PackedNode(x: toX(kind, cast[uint32](operand)), info: info)
+  if flags != {}:
+    t.withFlags.add (t.nodes.len.int32 - 1, flags)
+  if typeId != nilItemId:
+    t.withTypes.add (t.nodes.len.int32 - 1, typeId)
 
 proc prepare*(tree: var PackedTree; kind: TNodeKind; flags: TNodeFlags; typeId: PackedItemId; info: PackedLineInfo): PatchPos =
   result = PatchPos tree.nodes.len
-  tree.nodes.add PackedNode(kind: kind, flags: flags, operand: 0, info: info,
-                            typeId: typeId)
+  tree.addNode(kind = kind, flags = flags, operand = 0, info = info, typeId = typeId)
 
 proc prepare*(dest: var PackedTree; source: PackedTree; sourcePos: NodePos): PatchPos =
   result = PatchPos dest.nodes.len
@@ -186,26 +160,30 @@ proc prepare*(dest: var PackedTree; source: PackedTree; sourcePos: NodePos): Pat
 
 proc patch*(tree: var PackedTree; pos: PatchPos) =
   let pos = pos.int
-  assert tree.nodes[pos].kind > nkNilLit
+  let k = tree.nodes[pos].kind
+  assert k > nkNilLit
   let distance = int32(tree.nodes.len - pos)
-  tree.nodes[pos].operand = distance
+  assert distance > 0
+  tree.nodes[pos].x = toX(k, cast[uint32](distance))
 
 proc len*(tree: PackedTree): int {.inline.} = tree.nodes.len
 
-proc `[]`*(tree: PackedTree; i: int): lent PackedNode {.inline.} =
-  tree.nodes[i]
+proc `[]`*(tree: PackedTree; i: NodePos): lent PackedNode {.inline.} =
+  tree.nodes[i.int]
+
+template rawSpan(n: PackedNode): int = int(uoperand(n))
 
 proc nextChild(tree: PackedTree; pos: var int) {.inline.} =
   if tree.nodes[pos].kind > nkNilLit:
-    assert tree.nodes[pos].operand > 0
-    inc pos, tree.nodes[pos].operand
+    assert tree.nodes[pos].uoperand > 0
+    inc pos, tree.nodes[pos].rawSpan
   else:
     inc pos
 
 iterator sonsReadonly*(tree: PackedTree; n: NodePos): NodePos =
   var pos = n.int
   assert tree.nodes[pos].kind > nkNilLit
-  let last = pos + tree.nodes[pos].operand
+  let last = pos + tree.nodes[pos].rawSpan
   inc pos
   while pos < last:
     yield NodePos pos
@@ -226,7 +204,7 @@ iterator isons*(dest: var PackedTree; tree: PackedTree;
 iterator sonsFrom1*(tree: PackedTree; n: NodePos): NodePos =
   var pos = n.int
   assert tree.nodes[pos].kind > nkNilLit
-  let last = pos + tree.nodes[pos].operand
+  let last = pos + tree.nodes[pos].rawSpan
   inc pos
   if pos < last:
     nextChild tree, pos
@@ -240,7 +218,7 @@ iterator sonsWithoutLast2*(tree: PackedTree; n: NodePos): NodePos =
     inc count
   var pos = n.int
   assert tree.nodes[pos].kind > nkNilLit
-  let last = pos + tree.nodes[pos].operand
+  let last = pos + tree.nodes[pos].rawSpan
   inc pos
   while pos < last and count > 2:
     yield NodePos pos
@@ -250,7 +228,7 @@ iterator sonsWithoutLast2*(tree: PackedTree; n: NodePos): NodePos =
 proc parentImpl(tree: PackedTree; n: NodePos): NodePos =
   # finding the parent of a node is rather easy:
   var pos = n.int - 1
-  while pos >= 0 and (isAtom(tree, pos) or (pos + tree.nodes[pos].operand - 1 < n.int)):
+  while pos >= 0 and (isAtom(tree, pos) or (pos + tree.nodes[pos].rawSpan - 1 < n.int)):
     dec pos
   #assert pos >= 0, "node has no parent"
   result = NodePos(pos)
@@ -276,20 +254,32 @@ proc firstSon*(tree: PackedTree; n: NodePos): NodePos {.inline.} =
 proc kind*(tree: PackedTree; n: NodePos): TNodeKind {.inline.} =
   tree.nodes[n.int].kind
 proc litId*(tree: PackedTree; n: NodePos): LitId {.inline.} =
-  LitId tree.nodes[n.int].operand
+  LitId tree.nodes[n.int].uoperand
 proc info*(tree: PackedTree; n: NodePos): PackedLineInfo {.inline.} =
   tree.nodes[n.int].info
 
-template typ*(n: NodePos): PackedItemId =
-  tree.nodes[n.int].typeId
-template flags*(n: NodePos): TNodeFlags =
-  tree.nodes[n.int].flags
+proc findType*(tree: PackedTree; n: NodePos): PackedItemId =
+  for x in tree.withTypes:
+    if x[0] == int32(n): return x[1]
+    if x[0] > int32(n): return nilItemId
+  return nilItemId
 
-template operand*(n: NodePos): int32 =
-  tree.nodes[n.int].operand
+proc findFlags*(tree: PackedTree; n: NodePos): TNodeFlags =
+  for x in tree.withFlags:
+    if x[0] == int32(n): return x[1]
+    if x[0] > int32(n): return {}
+  return {}
+
+template typ*(n: NodePos): PackedItemId =
+  tree.findType(n)
+template flags*(n: NodePos): TNodeFlags =
+  tree.findFlags(n)
+
+template uoperand*(n: NodePos): uint32 =
+  tree.nodes[n.int].uoperand
 
 proc span*(tree: PackedTree; pos: int): int {.inline.} =
-  if isAtom(tree, pos): 1 else: tree.nodes[pos].operand
+  if isAtom(tree, pos): 1 else: tree.nodes[pos].rawSpan
 
 proc sons2*(tree: PackedTree; n: NodePos): (NodePos, NodePos) =
   assert(not isAtom(tree, n.int))
@@ -305,6 +295,7 @@ proc sons3*(tree: PackedTree; n: NodePos): (NodePos, NodePos, NodePos) =
   result = (NodePos a, NodePos b, NodePos c)
 
 proc ithSon*(tree: PackedTree; n: NodePos; i: int): NodePos =
+  result = default(NodePos)
   if tree.nodes[n.int].kind > nkNilLit:
     var count = 0
     for child in sonsReadonly(tree, n):
@@ -318,64 +309,28 @@ when false:
 
 template kind*(n: NodePos): TNodeKind = tree.nodes[n.int].kind
 template info*(n: NodePos): PackedLineInfo = tree.nodes[n.int].info
-template litId*(n: NodePos): LitId = LitId tree.nodes[n.int].operand
+template litId*(n: NodePos): LitId = LitId tree.nodes[n.int].uoperand
 
-template symId*(n: NodePos): SymId = SymId tree.nodes[n.int].operand
+template symId*(n: NodePos): SymId = SymId tree.nodes[n.int].soperand
 
 proc firstSon*(n: NodePos): NodePos {.inline.} = NodePos(n.int+1)
 
-when false:
-  # xxx `nkStrLit` or `nkStrLit..nkTripleStrLit:` below?
-  proc strLit*(tree: PackedTree; n: NodePos): lent string =
-    assert n.kind == nkStrLit
-    result = tree.sh.strings[LitId tree.nodes[n.int].operand]
-
-  proc strVal*(tree: PackedTree; n: NodePos): string =
-    assert n.kind == nkStrLit
-    result = tree.sh.strings[LitId tree.nodes[n.int].operand]
-    #result = cookedStrLit(raw)
-
-  proc filenameVal*(tree: PackedTree; n: NodePos): string =
-    case n.kind
-    of nkStrLit:
-      result = strVal(tree, n)
-    of nkIdent:
-      result = tree.sh.strings[n.litId]
-    of nkSym:
-      result = tree.sh.strings[tree.sh.syms[int n.symId].name]
-    else:
-      result = ""
-
-  proc identAsStr*(tree: PackedTree; n: NodePos): lent string =
-    assert n.kind == nkIdent
-    result = tree.sh.strings[LitId tree.nodes[n.int].operand]
-
 const
   externIntLit* = {nkCharLit,
     nkIntLit,
     nkInt8Lit,
     nkInt16Lit,
+    nkInt32Lit,
     nkInt64Lit,
     nkUIntLit,
     nkUInt8Lit,
     nkUInt16Lit,
     nkUInt32Lit,
-    nkUInt64Lit} # nkInt32Lit is missing by design!
+    nkUInt64Lit}
 
-  externSIntLit* = {nkIntLit, nkInt8Lit, nkInt16Lit, nkInt64Lit}
+  externSIntLit* = {nkIntLit, nkInt8Lit, nkInt16Lit, nkInt32Lit, nkInt64Lit}
   externUIntLit* = {nkUIntLit, nkUInt8Lit, nkUInt16Lit, nkUInt32Lit, nkUInt64Lit}
-  directIntLit* = nkInt32Lit
-
-when false:
-  proc identIdImpl(tree: PackedTree; n: NodePos): LitId =
-    if n.kind == nkIdent:
-      result = n.litId
-    elif n.kind == nkSym:
-      result = tree.sh.syms[int n.symId].name
-    else:
-      result = LitId(0)
-
-  template identId*(n: NodePos): LitId = identIdImpl(tree, n)
+  directIntLit* = nkNone
 
 template copyInto*(dest, n, body) =
   let patchPos = prepare(dest, tree, n)
@@ -387,28 +342,8 @@ template copyIntoKind*(dest, kind, info, body) =
   body
   patch dest, patchPos
 
-when false:
-  proc hasPragma*(tree: PackedTree; n: NodePos; pragma: string): bool =
-    let litId = tree.sh.strings.getKeyId(pragma)
-    if litId == LitId(0):
-      return false
-    assert n.kind == nkPragma
-    for ch0 in sonsReadonly(tree, n):
-      if ch0.kind == nkExprColonExpr:
-        if ch0.firstSon.identId == litId:
-          return true
-      elif ch0.identId == litId:
-        return true
-
 proc getNodeId*(tree: PackedTree): NodeId {.inline.} = NodeId tree.nodes.len
 
-when false:
-  proc produceError*(dest: var PackedTree; tree: PackedTree; n: NodePos; msg: string) =
-    let patchPos = prepare(dest, nkError, n.info)
-    dest.add nkStrLit, msg, n.info
-    copyTree(dest, tree, n)
-    patch dest, patchPos
-
 iterator allNodes*(tree: PackedTree): NodePos =
   var p = 0
   while p < tree.len:
@@ -418,3 +353,13 @@ iterator allNodes*(tree: PackedTree): NodePos =
 
 proc toPackedItemId*(item: int32): PackedItemId {.inline.} =
   PackedItemId(module: LitId(0), item: item)
+
+proc load*(f: var RodFile; t: var PackedTree) =
+  loadSeq f, t.nodes
+  loadSeq f, t.withFlags
+  loadSeq f, t.withTypes
+
+proc store*(f: var RodFile; t: PackedTree) =
+  storeSeq f, t.nodes
+  storeSeq f, t.withFlags
+  storeSeq f, t.withTypes

compiler/ic/replayer.nim

@@ -14,7 +14,7 @@
 import ".." / [ast, modulegraphs, trees, extccomp, btrees,
   msgs, lineinfos, pathutils, options, cgmeth]
 
-import tables
+import std/tables
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -103,6 +103,17 @@ proc replayBackendProcs*(g: ModuleGraph; module: int) =
     let symId = FullId(module: tmp.module, packed: it[1])
     g.enumToStringProcs[key] = LazySym(id: symId, sym: nil)
 
+  for it in mitems(g.packed[module].fromDisk.methodsPerType):
+    let key = translateId(it[0], g.packed, module, g.config)
+    let tmp = translateId(it[1], g.packed, module, g.config)
+    let symId = FullId(module: tmp.module, packed: it[1])
+    g.methodsPerType.mgetOrPut(key, @[]).add LazySym(id: symId, sym: nil)
+
+  for it in mitems(g.packed[module].fromDisk.dispatchers):
+    let tmp = translateId(it, g.packed, module, g.config)
+    let symId = FullId(module: tmp.module, packed: it)
+    g.dispatchers.add LazySym(id: symId, sym: nil)
+
 proc replayGenericCacheInformation*(g: ModuleGraph; module: int) =
   ## We remember the generic instantiations a module performed
   ## in order to to avoid the code bloat that generic code tends
@@ -127,12 +138,12 @@ proc replayGenericCacheInformation*(g: ModuleGraph; module: int) =
       module: module, sym: FullId(module: sym.module, packed: it.sym),
       concreteTypes: concreteTypes, inst: nil)
 
-  for it in mitems(g.packed[module].fromDisk.methodsPerType):
+  for it in mitems(g.packed[module].fromDisk.methodsPerGenericType):
     let key = translateId(it[0], g.packed, module, g.config)
     let col = it[1]
     let tmp = translateId(it[2], g.packed, module, g.config)
     let symId = FullId(module: tmp.module, packed: it[2])
-    g.methodsPerType.mgetOrPut(key, @[]).add (col, LazySym(id: symId, sym: nil))
+    g.methodsPerGenericType.mgetOrPut(key, @[]).add (col, LazySym(id: symId, sym: nil))
 
   replayBackendProcs(g, module)
 

compiler/ic/rodfiles.nim

@@ -14,7 +14,7 @@
 ##     compiler works and less a storage format, you're probably looking for
 ##     the `ic` or `packed_ast` modules to understand the logical format.
 
-from typetraits import supportsCopyMem
+from std/typetraits import supportsCopyMem
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions]
@@ -92,11 +92,16 @@ type
     typeInstCacheSection
     procInstCacheSection
     attachedOpsSection
-    methodsPerTypeSection
+    methodsPerGenericTypeSection
     enumToStringProcsSection
+    methodsPerTypeSection
+    dispatchersSection
     typeInfoSection  # required by the backend
     backendFlagsSection
     aliveSymsSection # beware, this is stored in a `.alivesyms` file.
+    sideChannelSection
+    namespaceSection
+    symnamesSection
 
   RodFileError* = enum
     ok, tooBig, cannotOpen, ioFailure, wrongHeader, wrongSection, configMismatch,
@@ -109,8 +114,8 @@ type
                        # better than exceptions.
 
 const
-  RodVersion = 1
-  cookie = [byte(0), byte('R'), byte('O'), byte('D'),
+  RodVersion = 2
+  defaultCookie = [byte(0), byte('R'), byte('O'), byte('D'),
             byte(sizeof(int)*8), byte(system.cpuEndian), byte(0), byte(RodVersion)]
 
 proc setError(f: var RodFile; err: RodFileError) {.inline.} =
@@ -206,16 +211,16 @@ proc loadSeq*[T](f: var RodFile; s: var seq[T]) =
     for i in 0..<lenPrefix:
       loadPrim(f, s[i])
 
-proc storeHeader*(f: var RodFile) =
+proc storeHeader*(f: var RodFile; cookie = defaultCookie) =
   ## stores the header which is described by `cookie`.
   if f.err != ok: return
   if f.f.writeBytes(cookie, 0, cookie.len) != cookie.len:
     setError f, ioFailure
 
-proc loadHeader*(f: var RodFile) =
+proc loadHeader*(f: var RodFile; cookie = defaultCookie) =
   ## Loads the header which is described by `cookie`.
   if f.err != ok: return
-  var thisCookie: array[cookie.len, byte]
+  var thisCookie: array[cookie.len, byte] = default(array[cookie.len, byte])
   if f.f.readBytes(thisCookie, 0, thisCookie.len) != thisCookie.len:
     setError f, ioFailure
   elif thisCookie != cookie:
@@ -231,13 +236,14 @@ proc storeSection*(f: var RodFile; s: RodSection) =
 proc loadSection*(f: var RodFile; expected: RodSection) =
   ## read the bytes value of s, sets and error if the section is incorrect.
   if f.err != ok: return
-  var s: RodSection
+  var s: RodSection = default(RodSection)
   loadPrim(f, s)
   if expected != s and f.err == ok:
     setError f, wrongSection
 
 proc create*(filename: string): RodFile =
   ## create the file and open it for writing
+  result = default(RodFile)
   if not open(result.f, filename, fmWrite):
     setError result, cannotOpen
 
@@ -245,5 +251,6 @@ proc close*(f: var RodFile) = close(f.f)
 
 proc open*(filename: string): RodFile =
   ## open the file for reading
+  result = default(RodFile)
   if not open(result.f, filename, fmRead):
     setError result, cannotOpen

compiler/idents.nim

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

compiler/importer.nim

@@ -10,10 +10,12 @@
 ## This module implements the symbol importing mechanism.
 
 import
-  intsets, ast, astalgo, msgs, options, idents, lookups,
-  semdata, modulepaths, sigmatch, lineinfos, sets,
-  modulegraphs, wordrecg, tables
-from strutils import `%`
+  ast, astalgo, msgs, options, idents, lookups,
+  semdata, modulepaths, sigmatch, lineinfos,
+  modulegraphs, wordrecg
+from std/strutils import `%`, startsWith
+from std/sequtils import addUnique
+import std/[sets, tables, intsets]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -113,6 +115,7 @@ proc rawImportSymbol(c: PContext, s, origin: PSym; importSet: var IntSet) =
 
 proc splitPragmas(c: PContext, n: PNode): (PNode, seq[TSpecialWord]) =
   template bail = globalError(c.config, n.info, "invalid pragma")
+  result = (nil, @[])
   if n.kind == nkPragmaExpr:
     if n.len == 2 and n[1].kind == nkPragma:
       result[0] = n[0]
@@ -228,11 +231,6 @@ 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 =
@@ -304,11 +302,18 @@ proc myImportModule(c: PContext, n: var PNode, importStmtResult: PNode): PSym =
       var prefix = ""
       if realModule.constraint != nil: prefix = realModule.constraint.strVal & "; "
       message(c.config, n.info, warnDeprecated, prefix & realModule.name.s & " is deprecated")
+    let moduleName = getModuleName(c.config, n)
+    if belongsToStdlib(c.graph, result) and not startsWith(moduleName, stdPrefix) and
+        not startsWith(moduleName, "system/") and not startsWith(moduleName, "packages/"):
+      message(c.config, n.info, warnStdPrefix, realModule.name.s)
     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) =
+  if isCachedModule(c.graph, m): return
   # fixes bug #17510, for re-exported symbols
   let realModuleId = c.importModuleMap[m.id]
   for s in allSyms(c.graph, m):

compiler/injectdestructors.nim

@@ -14,11 +14,13 @@
 ## See doc/destructors.rst for a spec of the implemented rewrite rules
 
 import
-  intsets, strtabs, ast, astalgo, msgs, renderer, magicsys, types, idents,
-  strutils, options, lowerings, tables, modulegraphs,
+  ast, astalgo, msgs, renderer, magicsys, types, idents,
+  options, lowerings, modulegraphs,
   lineinfos, parampatterns, sighashes, liftdestructors, optimizer,
   varpartitions, aliasanalysis, dfa, wordrecg
 
+import std/[strtabs, tables, strutils, intsets]
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -79,11 +81,11 @@ proc getTemp(c: var Con; s: var Scope; typ: PType; info: TLineInfo): PNode =
 proc nestedScope(parent: var Scope; body: PNode): Scope =
   Scope(vars: @[], locals: @[], wasMoved: @[], final: @[], body: body, needsTry: false, parent: addr(parent))
 
-proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSingleUsedTemp}): PNode
+proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSingleUsedTemp}; inReturn = false): PNode
 
 type
   MoveOrCopyFlag = enum
-    IsDecl, IsExplicitSink
+    IsDecl, IsExplicitSink, IsReturn
 
 proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope; flags: set[MoveOrCopyFlag] = {}): PNode
 
@@ -185,7 +187,9 @@ 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; inferredFromCopy = false) =
   var m = "'" & opname & "' is not available for type <" & typeToString(t) & ">"
@@ -207,10 +211,12 @@ proc checkForErrorPragma(c: Con; t: PType; ri: PNode; opname: string; inferredFr
       m.add " a 'sink' parameter"
   m.add "; routine: "
   m.add c.owner.name.s
+  #m.add "\n\n"
+  #m.add renderTree(c.body, {renderIds})
   localError(c.graph.config, ri.info, errGenerated, m)
 
 proc makePtrType(c: var Con, baseType: PType): PType =
-  result = newType(tyPtr, nextTypeId c.idgen, c.owner)
+  result = newType(tyPtr, c.idgen, c.owner)
   addSonSkipIntLit(result, baseType, c.idgen)
 
 proc genOp(c: var Con; op: PSym; dest: PNode): PNode =
@@ -270,7 +276,7 @@ proc deepAliases(dest, ri: PNode): bool =
 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:
@@ -432,6 +438,7 @@ 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)
@@ -733,7 +740,9 @@ template handleNestedTempl(n, processCall: untyped, willProduceStmt = false,
     result[^1] = maybeVoid(n[^1], s)
     dec c.inUncheckedAssignSection, inUncheckedAssignSection
 
-  else: assert(false)
+  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:
@@ -760,7 +769,7 @@ 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, nkPragmaBlock}:
     template process(child, s): untyped = p(child, c, s, mode)
@@ -850,7 +859,9 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
             result[i][1] = p(n[i][1], c, s, m)
         else:
           result[i] = p(n[i], c, s, m)
-      if mode == normal and isRefConstr:
+      if mode == normal and (isRefConstr or (hasDestructor(c, t) and
+        getAttachedOp(c.graph, t, attachedDestructor) != nil and
+        sfOverridden in getAttachedOp(c.graph, t, attachedDestructor).flags)):
         result = ensureDestruction(result, n, c, s)
     of nkCallKinds:
       if n[0].kind == nkSym and n[0].sym.magic == mEnsureMove:
@@ -944,7 +955,9 @@ 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)
@@ -1028,7 +1041,7 @@ 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)
@@ -1042,6 +1055,7 @@ 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 =
@@ -1153,7 +1167,8 @@ proc moveOrCopy(dest, ri: PNode; c: var Con; s: var Scope, flags: set[MoveOrCopy
         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(s, dest, ri, flags)
         result = newTree(nkStmtList, snk, c.genWasMoved(ri))

compiler/installer.ini

@@ -71,6 +71,7 @@ Files: "testament"
 Files: "nimsuggest"
 Files: "nimsuggest/tests/*.nim"
 Files: "changelogs/*.md"
+Files: "ci/funs.sh"
 
 [Lib]
 Files: "lib"

compiler/int128.nim

@@ -3,7 +3,7 @@
 ## hold all from `low(BiggestInt)` to `high(BiggestUInt)`, This
 ## type is for that purpose.
 
-from math import trunc
+from std/math import trunc
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -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)
@@ -357,9 +358,10 @@ proc `*`*(lhs, rhs: Int128): Int128 =
 proc `*=`*(a: var Int128, b: Int128) =
   a = a * b
 
-import bitops
+import std/bitops
 
 proc fastLog2*(a: Int128): int =
+  result = 0
   if a.udata[3] != 0:
     return 96 + fastLog2(a.udata[3])
   if a.udata[2] != 0:
@@ -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

@@ -11,7 +11,9 @@
 ## https://github.com/nim-lang/RFCs/issues/244 for more details.
 
 import
-  ast, types, renderer, intsets
+  ast, types, renderer
+
+import std/intsets
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -21,6 +23,7 @@ proc canAlias(arg, ret: PType; marker: var IntSet): bool
 proc canAliasN(arg: PType; n: PNode; marker: var IntSet): bool =
   case n.kind
   of nkRecList:
+    result = false
     for i in 0..<n.len:
       result = canAliasN(arg, n[i], marker)
       if result: return
@@ -36,7 +39,7 @@ proc canAliasN(arg: PType; n: PNode; marker: var IntSet): bool =
       else: discard
   of nkSym:
     result = canAlias(arg, n.sym.typ, marker)
-  else: discard
+  else: result = false
 
 proc canAlias(arg, ret: PType; marker: var IntSet): bool =
   if containsOrIncl(marker, ret.id):
@@ -56,6 +59,7 @@ 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
@@ -184,10 +188,12 @@ 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
@@ -197,6 +203,7 @@ 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

compiler/jsgen.nim

@@ -32,17 +32,18 @@ import
   ast, trees, magicsys, options,
   nversion, msgs, idents, types,
   ropes, ccgutils, wordrecg, renderer,
-  cgmeth, lowerings, sighashes, modulegraphs, lineinfos, rodutils,
+  cgmeth, lowerings, sighashes, modulegraphs, lineinfos,
   transf, injectdestructors, sourcemap, astmsgs, backendpragmas
 
 import pipelineutils
 
-import json, sets, math, tables, intsets
-import strutils except addf
+import std/[json, sets, math, tables, intsets]
+import std/strutils except addf
 
 when defined(nimPreviewSlimSystem):
   import std/[assertions, syncio]
 
+import std/formatfloat
 
 type
   TJSGen = object of PPassContext
@@ -50,6 +51,7 @@ type
     graph: ModuleGraph
     config: ConfigRef
     sigConflicts: CountTable[SigHash]
+    initProc: PProc
 
   BModule = ref TJSGen
   TJSTypeKind = enum       # necessary JS "types"
@@ -136,17 +138,15 @@ template nested(p, body) =
   dec p.extraIndent
 
 proc newGlobals(): PGlobals =
-  new(result)
-  result.forwarded = @[]
-  result.generatedSyms = initIntSet()
-  result.typeInfoGenerated = initIntSet()
+  result = PGlobals(forwarded: @[],
+        generatedSyms: initIntSet(),
+        typeInfoGenerated: initIntSet()
+        )
 
-proc initCompRes(r: var TCompRes) =
-  r.address = ""
-  r.res = ""
-  r.tmpLoc = ""
-  r.typ = etyNone
-  r.kind = resNone
+proc initCompRes(): TCompRes =
+  result = TCompRes(address: "", res: "",
+    tmpLoc: "", typ: etyNone, kind: resNone
+  )
 
 proc rdLoc(a: TCompRes): Rope {.inline.} =
   if a.typ != etyBaseIndex:
@@ -158,6 +158,8 @@ proc newProc(globals: PGlobals, module: BModule, procDef: PNode,
              options: TOptions): PProc =
   result = PProc(
     blocks: @[],
+    optionsStack: if module.initProc != nil: module.initProc.optionsStack
+                  else: @[],
     options: options,
     module: module,
     procDef: procDef,
@@ -216,7 +218,8 @@ proc mapType(typ: PType): TJSTypeKind =
     else: result = etyNone
   of tyProc: result = etyProc
   of tyCstring: result = etyString
-  of tyConcept, tyIterable: doAssert false
+  of tyConcept, tyIterable:
+    raiseAssert "unreachable"
 
 proc mapType(p: PProc; typ: PType): TJSTypeKind =
   result = mapType(typ)
@@ -345,8 +348,7 @@ proc isSimpleExpr(p: PProc; n: PNode): bool =
       if n[i].kind notin {nkCommentStmt, nkEmpty}: return false
     result = isSimpleExpr(p, n.lastSon)
   else:
-    if n.isAtom:
-      result = true
+    result = n.isAtom
 
 proc getTemp(p: PProc, defineInLocals: bool = true): Rope =
   inc(p.unique)
@@ -356,7 +358,7 @@ proc getTemp(p: PProc, defineInLocals: bool = true): Rope =
 
 proc genAnd(p: PProc, a, b: PNode, r: var TCompRes) =
   assert r.kind == resNone
-  var x, y: TCompRes
+  var x, y: TCompRes = default(TCompRes)
   if p.isSimpleExpr(a) and p.isSimpleExpr(b):
     gen(p, a, x)
     gen(p, b, y)
@@ -383,7 +385,7 @@ proc genAnd(p: PProc, a, b: PNode, r: var TCompRes) =
 
 proc genOr(p: PProc, a, b: PNode, r: var TCompRes) =
   assert r.kind == resNone
-  var x, y: TCompRes
+  var x, y: TCompRes = default(TCompRes)
   if p.isSimpleExpr(a) and p.isSimpleExpr(b):
     gen(p, a, x)
     gen(p, b, y)
@@ -471,6 +473,7 @@ const # magic checked op; magic unchecked op;
 proc needsTemp(p: PProc; n: PNode): bool =
   # check if n contains a call to determine
   # if a temp should be made to prevent multiple evals
+  result = false
   if n.kind in nkCallKinds + {nkTupleConstr, nkObjConstr, nkBracket, nkCurly}:
     return true
   for c in n:
@@ -506,8 +509,8 @@ proc maybeMakeTempAssignable(p: PProc, n: PNode; x: TCompRes): tuple[a, tmp: Rop
     elif x.tmpLoc != "" and n.kind == nkBracketExpr:
       # genArrayAddr
       var
-        address, index: TCompRes
-        first: Int128
+        address, index: TCompRes = default(TCompRes)
+        first: Int128 = Zero
       gen(p, n[0], address)
       gen(p, n[1], index)
       let (m1, tmp1) = maybeMakeTemp(p, n[0], address)
@@ -539,7 +542,7 @@ template binaryExpr(p: PProc, n: PNode, r: var TCompRes, magic, frmt: string,
   # $1 and $2 in the `frmt` string bind to lhs and rhs of the expr,
   # if $3 or $4 are present they will be substituted with temps for
   # lhs and rhs respectively
-  var x, y: TCompRes
+  var x, y: TCompRes = default(TCompRes)
   useMagic(p, magic)
   gen(p, n[1], x)
   gen(p, n[2], y)
@@ -569,7 +572,7 @@ proc signedTrimmer(size: BiggestInt): string =
 
 proc binaryUintExpr(p: PProc, n: PNode, r: var TCompRes, op: string,
                     reassign: static[bool] = false) =
-  var x, y: TCompRes
+  var x, y: TCompRes = default(TCompRes)
   gen(p, n[1], x)
   gen(p, n[2], y)
   let size = n[1].typ.skipTypes(abstractRange).size
@@ -608,8 +611,8 @@ template unaryExpr(p: PProc, n: PNode, r: var TCompRes, magic, frmt: string) =
 
 proc arithAux(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
   var
-    x, y: TCompRes
-    xLoc, yLoc: Rope
+    x, y: TCompRes = default(TCompRes)
+    xLoc, yLoc: Rope = ""
   let i = ord(optOverflowCheck notin p.options)
   useMagic(p, jsMagics[op][i])
   if n.len > 2:
@@ -673,8 +676,38 @@ proc arithAux(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
       applyFormat("modInt64($1, $2)", "$1 % $2")
     else:
       applyFormat("modInt($1, $2)", "Math.trunc($1 % $2)")
-  of mSucc: applyFormat("addInt($1, $2)", "($1 + $2)")
-  of mPred: applyFormat("subInt($1, $2)", "($1 - $2)")
+  of mSucc:
+    let typ = n[1].typ.skipTypes(abstractVarRange)
+    case typ.kind
+    of tyUInt..tyUInt32:
+      binaryUintExpr(p, n, r, "+")
+    of tyUInt64:
+      if optJsBigInt64 in p.config.globalOptions:
+        applyFormat("BigInt.asUintN(64, $1 + BigInt($2))")
+      else: binaryUintExpr(p, n, r, "+")
+    elif typ.kind == tyInt64 and optJsBigInt64 in p.config.globalOptions:
+      if optOverflowCheck notin p.options:
+        applyFormat("BigInt.asIntN(64, $1 + BigInt($2))")
+      else: binaryExpr(p, n, r, "addInt64", "addInt64($1, BigInt($2))")
+    else:
+      if optOverflowCheck notin p.options: applyFormat("$1 + $2")
+      else: binaryExpr(p, n, r, "addInt", "addInt($1, $2)")
+  of mPred:
+    let typ = n[1].typ.skipTypes(abstractVarRange)
+    case typ.kind
+    of tyUInt..tyUInt32:
+      binaryUintExpr(p, n, r, "-")
+    of tyUInt64:
+      if optJsBigInt64 in p.config.globalOptions:
+        applyFormat("BigInt.asUintN(64, $1 - BigInt($2))")
+      else: binaryUintExpr(p, n, r, "-")
+    elif typ.kind == tyInt64 and optJsBigInt64 in p.config.globalOptions:
+      if optOverflowCheck notin p.options:
+        applyFormat("BigInt.asIntN(64, $1 - BigInt($2))")
+      else: binaryExpr(p, n, r, "subInt64", "subInt64($1, BigInt($2))")
+    else:
+      if optOverflowCheck notin p.options: applyFormat("$1 - $2")
+      else: binaryExpr(p, n, r, "subInt", "subInt($1, $2)")
   of mAddF64: applyFormat("($1 + $2)", "($1 + $2)")
   of mSubF64: applyFormat("($1 - $2)", "($1 - $2)")
   of mMulF64: applyFormat("($1 * $2)", "($1 * $2)")
@@ -800,7 +833,7 @@ proc arith(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
     if mapType(n[1].typ) != etyBaseIndex:
       arithAux(p, n, r, op)
     else:
-      var x, y: TCompRes
+      var x, y: TCompRes = default(TCompRes)
       gen(p, n[1], x)
       gen(p, n[2], y)
       r.res = "($# == $# && $# == $#)" % [x.address, y.address, x.res, y.res]
@@ -833,7 +866,7 @@ proc genLineDir(p: PProc, n: PNode) =
       p.previousFileName = currentFileName
 
 proc genWhileStmt(p: PProc, n: PNode) =
-  var cond: TCompRes
+  var cond: TCompRes = default(TCompRes)
   internalAssert p.config, isEmptyType(n.typ)
   genLineDir(p, n)
   inc(p.unique)
@@ -928,6 +961,7 @@ proc genTry(p: PProc, n: PNode, r: var TCompRes) =
         elif it.kind == nkType:
           throwObj = it
         else:
+          throwObj = nil
           internalError(p.config, n.info, "genTryStmt")
 
         if orExpr != "": orExpr.add("||")
@@ -968,7 +1002,7 @@ proc genTry(p: PProc, n: PNode, r: var TCompRes) =
 
 proc genRaiseStmt(p: PProc, n: PNode) =
   if n[0].kind != nkEmpty:
-    var a: TCompRes
+    var a: TCompRes = default(TCompRes)
     gen(p, n[0], a)
     let typ = skipTypes(n[0].typ, abstractPtrs)
     genLineDir(p, n)
@@ -982,7 +1016,7 @@ proc genRaiseStmt(p: PProc, n: PNode) =
 
 proc genCaseJS(p: PProc, n: PNode, r: var TCompRes) =
   var
-    a, b, cond, stmt: TCompRes
+    a, b, cond, stmt: TCompRes = default(TCompRes)
   genLineDir(p, n)
   gen(p, n[0], cond)
   let typeKind = skipTypes(n[0].typ, abstractVar).kind
@@ -1116,7 +1150,7 @@ proc genAsmOrEmitStmt(p: PProc, n: PNode) =
       if false:
         discard
       else:
-        var r: TCompRes
+        var r = default(TCompRes)
         gen(p, it, r)
 
         if it.typ.kind == tyPointer:
@@ -1132,13 +1166,13 @@ proc genAsmOrEmitStmt(p: PProc, n: PNode) =
 
         p.body.add(r.rdLoc)
     else:
-      var r: TCompRes
+      var r: TCompRes = default(TCompRes)
       gen(p, it, r)
       p.body.add(r.rdLoc)
   p.body.add "\L"
 
 proc genIf(p: PProc, n: PNode, r: var TCompRes) =
-  var cond, stmt: TCompRes
+  var cond, stmt: TCompRes = default(TCompRes)
   var toClose = 0
   if not isEmptyType(n.typ):
     r.kind = resVal
@@ -1175,6 +1209,7 @@ proc generateHeader(p: PProc, typ: PType): Rope =
       result.add("_Idx")
 
 proc countJsParams(typ: PType): int =
+  result = 0
   for i in 1..<typ.n.len:
     assert(typ.n[i].kind == nkSym)
     var param = typ.n[i].sym
@@ -1198,7 +1233,7 @@ proc needsNoCopy(p: PProc; y: PNode): bool =
             {tyRef, tyPtr, tyLent, tyVar, tyCstring, tyProc, tyOwned} + IntegralTypes))
 
 proc genAsgnAux(p: PProc, x, y: PNode, noCopyNeeded: bool) =
-  var a, b: TCompRes
+  var a, b: TCompRes = default(TCompRes)
   var xtyp = mapType(p, x.typ)
 
   # disable `[]=` for cstring
@@ -1277,7 +1312,7 @@ proc genFastAsgn(p: PProc, n: PNode) =
   genAsgnAux(p, n[0], n[1], noCopyNeeded=noCopy)
 
 proc genSwap(p: PProc, n: PNode) =
-  var a, b: TCompRes
+  var a, b: TCompRes = default(TCompRes)
   gen(p, n[1], a)
   gen(p, n[2], b)
   var tmp = p.getTemp(false)
@@ -1295,10 +1330,12 @@ proc getFieldPosition(p: PProc; f: PNode): int =
   case f.kind
   of nkIntLit..nkUInt64Lit: result = int(f.intVal)
   of nkSym: result = f.sym.position
-  else: internalError(p.config, f.info, "genFieldPosition")
+  else:
+    result = 0
+    internalError(p.config, f.info, "genFieldPosition")
 
 proc genFieldAddr(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   r.typ = etyBaseIndex
   let b = if n.kind == nkHiddenAddr: n[0] else: n
   gen(p, b[0], a)
@@ -1362,10 +1399,10 @@ proc genCheckedFieldOp(p: PProc, n: PNode, addrTyp: PType, r: var TCompRes) =
   internalAssert p.config, disc.kind == skField
   if disc.loc.r == "": disc.loc.r = mangleName(p.module, disc)
 
-  var setx: TCompRes
+  var setx: TCompRes = default(TCompRes)
   gen(p, checkExpr[1], setx)
 
-  var obj: TCompRes
+  var obj: TCompRes = default(TCompRes)
   gen(p, accessExpr[0], obj)
   # Avoid evaluating the LHS twice (one to read the discriminant and one to read
   # the field)
@@ -1391,8 +1428,8 @@ proc genCheckedFieldOp(p: PProc, n: PNode, addrTyp: PType, r: var TCompRes) =
 
 proc genArrayAddr(p: PProc, n: PNode, r: var TCompRes) =
   var
-    a, b: TCompRes
-    first: Int128
+    a, b: TCompRes = default(TCompRes)
+    first: Int128 = Zero
   r.typ = etyBaseIndex
   let m = if n.kind == nkHiddenAddr: n[0] else: n
   gen(p, m[0], a)
@@ -1639,7 +1676,7 @@ proc genDeref(p: PProc, n: PNode, r: var TCompRes) =
   if t == etyObject or it.typ.kind == tyLent:
     gen(p, it, r)
   else:
-    var a: TCompRes
+    var a: TCompRes = default(TCompRes)
     gen(p, it, a)
     r.kind = a.kind
     r.typ = mapType(p, n.typ)
@@ -1656,7 +1693,7 @@ proc genDeref(p: PProc, n: PNode, r: var TCompRes) =
       internalError(p.config, n.info, "genDeref")
 
 proc genArgNoParam(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   gen(p, n, a)
   if a.typ == etyBaseIndex:
     r.res.add(a.address)
@@ -1666,7 +1703,7 @@ proc genArgNoParam(p: PProc, n: PNode, r: var TCompRes) =
     r.res.add(a.res)
 
 proc genArg(p: PProc, n: PNode, param: PSym, r: var TCompRes; emitted: ptr int = nil) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   gen(p, n, a)
   if skipTypes(param.typ, abstractVar).kind in {tyOpenArray, tyVarargs} and
       a.typ == etyBaseIndex:
@@ -1790,7 +1827,7 @@ proc genInfixCall(p: PProc, n: PNode, r: var TCompRes) =
       r.address = ""
       r.typ = etyNone
     r.res.add(".")
-  var op: TCompRes
+  var op: TCompRes = default(TCompRes)
   gen(p, n[0], op)
   r.res.add(op.res)
   genArgs(p, n, r, 2)
@@ -1938,7 +1975,7 @@ proc createVar(p: PProc, typ: PType, indirect: bool): Rope =
     result.add("}")
     if indirect: result = "[$1]" % [result]
   of tyObject:
-    var initList: Rope
+    var initList: Rope = ""
     createObjInitList(p, t, initIntSet(), initList)
     result = ("({$1})") % [initList]
     if indirect: result = "[$1]" % [result]
@@ -1965,7 +2002,7 @@ template returnType: untyped = ""
 
 proc genVarInit(p: PProc, v: PSym, n: PNode) =
   var
-    a: TCompRes
+    a: TCompRes = default(TCompRes)
     s: Rope
     varCode: string
     varName = mangleName(p.module, v)
@@ -2066,7 +2103,7 @@ proc genConstant(p: PProc, c: PSym) =
     p.body = oldBody
 
 proc genNew(p: PProc, n: PNode) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   gen(p, n[1], a)
   var t = skipTypes(n[1].typ, abstractVar)[0]
   if mapType(t) == etyObject:
@@ -2077,7 +2114,7 @@ proc genNew(p: PProc, n: PNode) =
     lineF(p, "$1 = [[$2], 0];$n", [a.rdLoc, createVar(p, t, false)])
 
 proc genNewSeq(p: PProc, n: PNode) =
-  var x, y: TCompRes
+  var x, y: TCompRes = default(TCompRes)
   gen(p, n[1], x)
   gen(p, n[2], y)
   let t = skipTypes(n[1].typ, abstractVar)[0]
@@ -2095,7 +2132,7 @@ proc genOrd(p: PProc, n: PNode, r: var TCompRes) =
   else: internalError(p.config, n.info, "genOrd")
 
 proc genConStrStr(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
 
   gen(p, n[1], a)
   r.kind = resExpr
@@ -2120,7 +2157,7 @@ proc genConStrStr(p: PProc, n: PNode, r: var TCompRes) =
 proc genReprAux(p: PProc, n: PNode, r: var TCompRes, magic: string, typ: Rope = "") =
   useMagic(p, magic)
   r.res.add(magic & "(")
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
 
   gen(p, n[1], a)
   if magic == "reprAny":
@@ -2167,7 +2204,7 @@ proc genRepr(p: PProc, n: PNode, r: var TCompRes) =
   r.kind = resExpr
 
 proc genOf(p: PProc, n: PNode, r: var TCompRes) =
-  var x: TCompRes
+  var x: TCompRes = default(TCompRes)
   let t = skipTypes(n[2].typ,
                     abstractVarRange+{tyRef, tyPtr, tyLent, tyTypeDesc, tyOwned})
   gen(p, n[1], x)
@@ -2183,7 +2220,7 @@ proc genDefault(p: PProc, n: PNode; r: var TCompRes) =
   r.kind = resExpr
 
 proc genReset(p: PProc, n: PNode) =
-  var x: TCompRes
+  var x: TCompRes = default(TCompRes)
   useMagic(p, "genericReset")
   gen(p, n[1], x)
   if x.typ == etyBaseIndex:
@@ -2194,7 +2231,7 @@ proc genReset(p: PProc, n: PNode) =
                   genTypeInfo(p, n[1].typ), tmp])
 
 proc genMove(p: PProc; n: PNode; r: var TCompRes) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   r.kind = resVal
   r.res = p.getTemp()
   gen(p, n[1], a)
@@ -2203,14 +2240,14 @@ proc genMove(p: PProc; n: PNode; r: var TCompRes) =
   #lineF(p, "$1 = $2;$n", [dest.rdLoc, src.rdLoc])
 
 proc genDup(p: PProc; n: PNode; r: var TCompRes) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   r.kind = resVal
   r.res = p.getTemp()
   gen(p, n[1], a)
   lineF(p, "$1 = $2;$n", [r.rdLoc, a.rdLoc])
 
 proc genJSArrayConstr(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   r.res = rope("[")
   r.kind = resExpr
   for i in 0 ..< n.len:
@@ -2241,7 +2278,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
     binaryExpr(p, n, r, "addChar",
         "addChar($1, $2);")
   of mAppendStrStr:
-    var lhs, rhs: TCompRes
+    var lhs, rhs: TCompRes = default(TCompRes)
     gen(p, n[1], lhs)
     gen(p, n[2], rhs)
 
@@ -2254,7 +2291,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
       r.res = "$1.push.apply($3, $2);" % [a, rhs.rdLoc, tmp]
     r.kind = resExpr
   of mAppendSeqElem:
-    var x, y: TCompRes
+    var x, y: TCompRes = default(TCompRes)
     gen(p, n[1], x)
     gen(p, n[2], y)
     if mapType(n[2].typ) == etyBaseIndex:
@@ -2282,7 +2319,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
     if mapType(n[1].typ) != etyBaseIndex:
       unaryExpr(p, n, r, "", "($1 == null)")
     else:
-      var x: TCompRes
+      var x: TCompRes = default(TCompRes)
       gen(p, n[1], x)
       r.res = "($# == null && $# === 0)" % [x.address, x.res]
   of mEnumToStr: genRepr(p, n, r)
@@ -2293,7 +2330,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
     if n[1].kind == nkBracket:
       genJSArrayConstr(p, n[1], r)
     else:
-      var x: TCompRes
+      var x: TCompRes = default(TCompRes)
       gen(p, n[1], x)
       useMagic(p, "nimCopy")
       r.res = "nimCopy(null, $1, $2)" % [x.rdLoc, genTypeInfo(p, n.typ)]
@@ -2302,7 +2339,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
   of mDestroy, mTrace: discard "ignore calls to the default destructor"
   of mOrd: genOrd(p, n, r)
   of mLengthStr, mLengthSeq, mLengthOpenArray, mLengthArray:
-    var x: TCompRes
+    var x: TCompRes = default(TCompRes)
     gen(p, n[1], x)
     if skipTypes(n[1].typ, abstractInst).kind == tyCstring:
       let (a, tmp) = maybeMakeTemp(p, n[1], x)
@@ -2311,7 +2348,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
       r.res = "($1).length" % [x.rdLoc]
     r.kind = resExpr
   of mHigh:
-    var x: TCompRes
+    var x: TCompRes = default(TCompRes)
     gen(p, n[1], x)
     if skipTypes(n[1].typ, abstractInst).kind == tyCstring:
       let (a, tmp) = maybeMakeTemp(p, n[1], x)
@@ -2343,7 +2380,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
     of tyUInt64:
       if optJsBigInt64 in p.config.globalOptions:
         binaryExpr(p, n, r, "", "$1 = BigInt.asUintN(64, $3 - BigInt($2))", true)
-      else: binaryUintExpr(p, n, r, "+", true)
+      else: binaryUintExpr(p, n, r, "-", true)
     elif typ.kind == tyInt64 and optJsBigInt64 in p.config.globalOptions:
       if optOverflowCheck notin p.options:
         binaryExpr(p, n, r, "", "$1 = BigInt.asIntN(64, $3 - BigInt($2))", true)
@@ -2356,7 +2393,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
       """if ($1.length < $2) { for (var i = $3.length; i < $4; ++i) $3.push(0); }
          else {$3.length = $4; }""")
   of mSetLengthSeq:
-    var x, y: TCompRes
+    var x, y: TCompRes = default(TCompRes)
     gen(p, n[1], x)
     gen(p, n[2], y)
     let t = skipTypes(n[1].typ, abstractVar)[0]
@@ -2395,7 +2432,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
     genCall(p, n, r)
   of mSlice:
     # arr.slice([begin[, end]]): 'end' is exclusive
-    var x, y, z: TCompRes
+    var x, y, z: TCompRes = default(TCompRes)
     gen(p, n[1], x)
     gen(p, n[2], y)
     gen(p, n[3], z)
@@ -2413,7 +2450,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
 
 proc genSetConstr(p: PProc, n: PNode, r: var TCompRes) =
   var
-    a, b: TCompRes
+    a, b: TCompRes = default(TCompRes)
   useMagic(p, "setConstr")
   r.res = rope("setConstr(")
   r.kind = resExpr
@@ -2450,7 +2487,7 @@ proc genArrayConstr(p: PProc, n: PNode, r: var TCompRes) =
     # generate typed array
     # for example Nim generates `new Uint8Array([1, 2, 3])` for `[byte(1), 2, 3]`
     # TODO use `set` or loop to initialize typed array which improves performances in some situations
-    var a: TCompRes
+    var a: TCompRes = default(TCompRes)
     r.res = "new $1([" % [rope(jsTyp)]
     r.kind = resExpr
     for i in 0 ..< n.len:
@@ -2462,7 +2499,7 @@ proc genArrayConstr(p: PProc, n: PNode, r: var TCompRes) =
     genJSArrayConstr(p, n, r)
 
 proc genTupleConstr(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   r.res = rope("{")
   r.kind = resExpr
   for i in 0..<n.len:
@@ -2481,9 +2518,9 @@ proc genTupleConstr(p: PProc, n: PNode, r: var TCompRes) =
   r.res.add("}")
 
 proc genObjConstr(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes
+  var a: TCompRes = default(TCompRes)
   r.kind = resExpr
-  var initList : Rope
+  var initList : Rope = ""
   var fieldIDs = initIntSet()
   let nTyp = n.typ.skipTypes(abstractInst)
   for i in 1..<n.len:
@@ -2557,16 +2594,23 @@ proc upConv(p: PProc, n: PNode, r: var TCompRes) =
   gen(p, n[0], r)        # XXX
 
 proc genRangeChck(p: PProc, n: PNode, r: var TCompRes, magic: string) =
-  var a, b: TCompRes
+  var a, b: TCompRes = default(TCompRes)
   gen(p, n[0], r)
   let src = skipTypes(n[0].typ, abstractVarRange)
   let dest = skipTypes(n.typ, abstractVarRange)
-  if src.kind in {tyInt64, tyUInt64} and dest.kind notin {tyInt64, tyUInt64} and optJsBigInt64 in p.config.globalOptions:
-    r.res = "Number($1)" % [r.res]
-  if optRangeCheck notin p.options or (dest.kind in {tyUInt..tyUInt64} and
-      checkUnsignedConversions notin p.config.legacyFeatures):
-    discard "XXX maybe emit masking instructions here"
+  if optRangeCheck notin p.options:
+    return
+  elif dest.kind in {tyUInt..tyUInt64} and checkUnsignedConversions notin p.config.legacyFeatures:
+    if src.kind in {tyInt64, tyUInt64} and optJsBigInt64 in p.config.globalOptions:
+      r.res = "BigInt.asUintN($1, $2)" % [$(dest.size * 8), r.res]
+    else:
+      r.res = "BigInt.asUintN($1, BigInt($2))" % [$(dest.size * 8), r.res]
+    if not (dest.kind == tyUInt64 and optJsBigInt64 in p.config.globalOptions):
+      r.res = "Number($1)" % [r.res]
   else:
+    if src.kind in {tyInt64, tyUInt64} and dest.kind notin {tyInt64, tyUInt64} and optJsBigInt64 in p.config.globalOptions:
+      # we do a range check anyway, so it's ok if the number gets rounded
+      r.res = "Number($1)" % [r.res]
     gen(p, n[1], a)
     gen(p, n[2], b)
     useMagic(p, "chckRange")
@@ -2643,9 +2687,10 @@ proc optionalLine(p: Rope): Rope =
 
 proc genProc(oldProc: PProc, prc: PSym): Rope =
   ## Generate a JS procedure ('function').
+  result = ""
   var
     resultSym: PSym
-    a: TCompRes
+    a: TCompRes = default(TCompRes)
   #if gVerbosity >= 3:
   #  echo "BEGIN generating code for: " & prc.name.s
   var p = newProc(oldProc.g, oldProc.module, prc.ast, prc.options)
@@ -2673,7 +2718,7 @@ proc genProc(oldProc: PProc, prc: PSym): Rope =
     else:
       returnStmt = "return $#;$n" % [a.res]
 
-  var transformedBody = transformBody(p.module.graph, p.module.idgen, prc, dontUseCache)
+  var transformedBody = transformBody(p.module.graph, p.module.idgen, prc, {})
   if sfInjectDestructors in prc.flags:
     transformedBody = injectDestructorCalls(p.module.graph, p.module.idgen, prc, transformedBody)
 
@@ -2725,7 +2770,7 @@ proc genProc(oldProc: PProc, prc: PSym): Rope =
   #  echo "END   generated code for: " & prc.name.s
 
 proc genStmt(p: PProc, n: PNode) =
-  var r: TCompRes
+  var r: TCompRes = default(TCompRes)
   gen(p, n, r)
   if r.res != "": lineF(p, "$#;$n", [r.res])
 
@@ -2856,7 +2901,11 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
       r.res = rope"Infinity"
     of fcNegInf:
       r.res = rope"-Infinity"
-    else: r.res = rope(f.toStrMaxPrecision)
+    else:
+      if n.typ.skipTypes(abstractVarRange).kind == tyFloat32:
+        r.res.addFloatRoundtrip(f.float32)
+      else:
+        r.res.addFloatRoundtrip(f)
     r.kind = resExpr
   of nkCallKinds:
     if isEmptyType(n.typ):
@@ -2957,13 +3006,11 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
 
 proc newModule(g: ModuleGraph; module: PSym): BModule =
   ## Create a new JS backend module node.
-  new(result)
-  result.module = module
-  result.sigConflicts = initCountTable[SigHash]()
   if g.backend == nil:
     g.backend = newGlobals()
-  result.graph = g
-  result.config = g.config
+  result = BModule(module: module, sigConflicts: initCountTable[SigHash](),
+                   graph: g, config: g.config
+  )
   if sfSystemModule in module.flags:
     PGlobals(g.backend).inSystem = true
 
@@ -3036,6 +3083,7 @@ proc processJSCodeGen*(b: PPassContext, n: PNode): PNode =
   if m.module == nil: internalError(m.config, n.info, "myProcess")
   let globals = PGlobals(m.graph.backend)
   var p = newInitProc(globals, m)
+  m.initProc = p
   p.unique = globals.unique
   genModule(p, n)
   p.g.code.add(p.locals)
@@ -3049,9 +3097,8 @@ proc wholeCode(graph: ModuleGraph; m: BModule): Rope =
       var p = newInitProc(globals, m)
       attachProc(p, prc)
 
-  var disp = generateMethodDispatchers(graph, m.idgen)
-  for i in 0..<disp.len:
-    let prc = disp[i].sym
+  generateIfMethodDispatchers(graph, m.idgen)
+  for prc in getDispatchers(graph):
     if not globals.generatedSyms.containsOrIncl(prc.id):
       var p = newInitProc(globals, m)
       attachProc(p, prc)

compiler/lambdalifting.nim

@@ -10,10 +10,12 @@
 # This file implements lambda lifting for the transformator.
 
 import
-  intsets, strutils, options, ast, astalgo, msgs,
-  idents, renderer, types, magicsys, lowerings, tables, modulegraphs, lineinfos,
+  options, ast, astalgo, msgs,
+  idents, renderer, types, magicsys, lowerings, modulegraphs, lineinfos,
   transf, liftdestructors, typeallowed
 
+import std/[strutils, tables, intsets]
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -133,10 +135,10 @@ proc createClosureIterStateType*(g: ModuleGraph; iter: PSym; idgen: IdGenerator)
   var n = newNodeI(nkRange, iter.info)
   n.add newIntNode(nkIntLit, -1)
   n.add newIntNode(nkIntLit, 0)
-  result = newType(tyRange, nextTypeId(idgen), iter)
+  result = newType(tyRange, idgen, iter)
   result.n = n
   var intType = nilOrSysInt(g)
-  if intType.isNil: intType = newType(tyInt, nextTypeId(idgen), iter)
+  if intType.isNil: intType = newType(tyInt, idgen, iter)
   rawAddSon(result, intType)
 
 proc createStateField(g: ModuleGraph; iter: PSym; idgen: IdGenerator): PSym =
@@ -187,6 +189,8 @@ proc getEnvParam*(routine: PSym): PSym =
   if hidden.kind == nkSym and hidden.sym.name.s == paramName:
     result = hidden.sym
     assert sfFromGeneric in result.flags
+  else:
+    result = nil
 
 proc interestingVar(s: PSym): bool {.inline.} =
   result = s.kind in {skVar, skLet, skTemp, skForVar, skParam, skResult} and
@@ -199,6 +203,8 @@ proc illegalCapture(s: PSym): bool {.inline.} =
 proc isInnerProc(s: PSym): bool =
   if s.kind in {skProc, skFunc, skMethod, skConverter, skIterator} and s.magic == mNone:
     result = s.skipGenericOwner.kind in routineKinds
+  else:
+    result = false
 
 proc newAsgnStmt(le, ri: PNode, info: TLineInfo): PNode =
   # Bugfix: unfortunately we cannot use 'nkFastAsgn' here as that would
@@ -293,33 +299,34 @@ proc freshVarForClosureIter*(g: ModuleGraph; s: PSym; idgen: IdGenerator; owner:
 
 proc markAsClosure(g: ModuleGraph; owner: PSym; n: PNode) =
   let s = n.sym
+  let isEnv = s.name.id == getIdent(g.cache, ":env").id
   if illegalCapture(s):
     localError(g.config, n.info,
       ("'$1' is of type <$2> which cannot be captured as it would violate memory" &
        " safety, declared here: $3; using '-d:nimNoLentIterators' helps in some cases." &
        " Consider using a <ref $2> which can be captured.") %
       [s.name.s, typeToString(s.typ), g.config$s.info])
-  elif not (owner.typ.callConv == ccClosure or owner.typ.callConv == ccNimCall and tfExplicitCallConv notin owner.typ.flags):
+  elif not (owner.typ.isClosure or owner.isNimcall and not owner.isExplicitCallConv or isEnv):
     localError(g.config, n.info, "illegal capture '$1' because '$2' has the calling convention: <$3>" %
       [s.name.s, owner.name.s, $owner.typ.callConv])
   incl(owner.typ.flags, tfCapturesEnv)
-  owner.typ.callConv = ccClosure
+  if not isEnv:
+    owner.typ.callConv = ccClosure
 
 type
   DetectionPass = object
     processed, capturedVars: IntSet
     ownerToType: Table[int, PType]
     somethingToDo: bool
+    inTypeOf: bool
     graph: ModuleGraph
     idgen: IdGenerator
 
 proc initDetectionPass(g: ModuleGraph; fn: PSym; idgen: IdGenerator): DetectionPass =
-  result.processed = initIntSet()
-  result.capturedVars = initIntSet()
-  result.ownerToType = initTable[int, PType]()
-  result.processed.incl(fn.id)
-  result.graph = g
-  result.idgen = idgen
+  result = DetectionPass(processed: toIntSet([fn.id]),
+    capturedVars: initIntSet(), ownerToType: initTable[int, PType](),
+    graph: g, idgen: idgen
+  )
 
 discard """
 proc outer =
@@ -335,7 +342,7 @@ proc getEnvTypeForOwner(c: var DetectionPass; owner: PSym;
                         info: TLineInfo): PType =
   result = c.ownerToType.getOrDefault(owner.id)
   if result.isNil:
-    result = newType(tyRef, nextTypeId(c.idgen), owner)
+    result = newType(tyRef, c.idgen, owner)
     let obj = createEnvObj(c.graph, c.idgen, owner, info)
     rawAddSon(result, obj)
     c.ownerToType[owner.id] = result
@@ -343,7 +350,7 @@ proc getEnvTypeForOwner(c: var DetectionPass; owner: PSym;
 proc asOwnedRef(c: var DetectionPass; t: PType): PType =
   if optOwnedRefs in c.graph.config.globalOptions:
     assert t.kind == tyRef
-    result = newType(tyOwned, nextTypeId(c.idgen), t.owner)
+    result = newType(tyOwned, c.idgen, t.owner)
     result.flags.incl tfHasOwned
     result.rawAddSon t
   else:
@@ -352,7 +359,7 @@ proc asOwnedRef(c: var DetectionPass; t: PType): PType =
 proc getEnvTypeForOwnerUp(c: var DetectionPass; owner: PSym;
                           info: TLineInfo): PType =
   var r = c.getEnvTypeForOwner(owner, info)
-  result = newType(tyPtr, nextTypeId(c.idgen), owner)
+  result = newType(tyPtr, c.idgen, owner)
   rawAddSon(result, r.skipTypes({tyOwned, tyRef, tyPtr}))
 
 proc createUpField(c: var DetectionPass; dest, dep: PSym; info: TLineInfo) =
@@ -413,6 +420,9 @@ 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
@@ -441,15 +451,18 @@ proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
     if innerProc:
       if s.isIterator: c.somethingToDo = true
       if not c.processed.containsOrIncl(s.id):
-        let body = transformBody(c.graph, c.idgen, s, useCache)
+        let body = transformBody(c.graph, c.idgen, s, {useCache})
         detectCapturedVars(body, s, c)
     let ow = s.skipGenericOwner
+    let innerClosure = innerProc and s.typ.callConv == ccClosure and not s.isIterator
+    let interested = interestingVar(s)
     if ow == owner:
       if owner.isIterator:
         c.somethingToDo = true
         addClosureParam(c, owner, n.info)
         if interestingIterVar(s):
-          if not c.capturedVars.containsOrIncl(s.id):
+          if not c.capturedVars.contains(s.id):
+            if not c.inTypeOf: c.capturedVars.incl(s.id)
             let obj = getHiddenParam(c.graph, owner).typ.skipTypes({tyOwned, tyRef, tyPtr})
             #let obj = c.getEnvTypeForOwner(s.owner).skipTypes({tyOwned, tyRef, tyPtr})
 
@@ -458,7 +471,7 @@ 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 +488,12 @@ 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 +525,14 @@ 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 +542,8 @@ 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
@@ -711,6 +730,7 @@ proc symToClosure(n: PNode; owner: PSym; d: var DetectionPass;
     # direct dependency, so use the outer's env variable:
     result = makeClosure(d.graph, d.idgen, s, setupEnvVar(owner, d, c, n.info), n.info)
   else:
+    result = nil
     let available = getHiddenParam(d.graph, owner)
     let wanted = getHiddenParam(d.graph, s).typ
     # ugh: call through some other inner proc;
@@ -737,7 +757,7 @@ proc liftCapturedVars(n: PNode; owner: PSym; d: var DetectionPass;
         #  echo renderTree(s.getBody, {renderIds})
         let oldInContainer = c.inContainer
         c.inContainer = 0
-        var body = transformBody(d.graph, d.idgen, s, dontUseCache)
+        var body = transformBody(d.graph, d.idgen, s, {})
         body = liftCapturedVars(body, s, d, c)
         if c.envVars.getOrDefault(s.id).isNil:
           s.transformedBody = body
@@ -792,6 +812,8 @@ proc liftCapturedVars(n: PNode; owner: PSym; d: var DetectionPass;
   of nkTypeOfExpr:
     result = n
   else:
+    if n.isCallExpr and n[0].isTypeOf:
+      return
     if owner.isIterator:
       if nfLL in n.flags:
         # special case 'when nimVm' due to bug #3636:
@@ -859,7 +881,7 @@ proc liftIterToProc*(g: ModuleGraph; fn: PSym; body: PNode; ptrType: PType;
   fn.typ.callConv = oldCC
 
 proc liftLambdas*(g: ModuleGraph; fn: PSym, body: PNode; tooEarly: var bool;
-                  idgen: IdGenerator, force: bool): PNode =
+                  idgen: IdGenerator; flags: TransformFlags): PNode =
   # XXX backend == backendJs does not suffice! The compiletime stuff needs
   # the transformation even when compiling to JS ...
 
@@ -868,7 +890,7 @@ proc liftLambdas*(g: ModuleGraph; fn: PSym, body: PNode; tooEarly: var bool;
 
   if body.kind == nkEmpty or (
       g.config.backend == backendJs and not isCompileTime) or
-      (fn.skipGenericOwner.kind != skModule and not force):
+      (fn.skipGenericOwner.kind != skModule and force notin flags):
 
     # ignore forward declaration:
     result = body
@@ -936,7 +958,7 @@ 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()

compiler/lexer.nim

@@ -16,8 +16,10 @@
 # DOS or Macintosh text files, even when it is not the native format.
 
 import
-  hashes, options, msgs, strutils, platform, idents, nimlexbase, llstream,
-  wordrecg, lineinfos, pathutils, parseutils
+  options, msgs, platform, idents, nimlexbase, llstream,
+  wordrecg, lineinfos, pathutils
+
+import std/[hashes, parseutils, strutils]
 
 when defined(nimPreviewSlimSystem):
   import std/[assertions, formatfloat]
@@ -120,7 +122,6 @@ type
                               # this is needed because scanning comments
                               # needs so much look-ahead
     currLineIndent*: int
-    strongSpaces*, allowTabs*: bool
     errorHandler*: ErrorHandler
     cache*: IdentCache
     when defined(nimsuggest):
@@ -148,9 +149,11 @@ proc isNimIdentifier*(s: string): bool =
     var i = 1
     while i < sLen:
       if s[i] == '_': inc(i)
-      if i < sLen and s[i] notin SymChars: return
+      if i < sLen and s[i] notin SymChars: return false
       inc(i)
     result = true
+  else:
+    result = false
 
 proc `$`*(tok: Token): string =
   case tok.tokType
@@ -172,32 +175,6 @@ proc printTok*(conf: ConfigRef; tok: Token) =
   # xxx factor with toLocation
   msgWriteln(conf, $tok.line & ":" & $tok.col & "\t" & $tok.tokType & " " & $tok)
 
-proc initToken*(L: var Token) =
-  L.tokType = tkInvalid
-  L.iNumber = 0
-  L.indent = 0
-  L.spacing = {}
-  L.literal = ""
-  L.fNumber = 0.0
-  L.base = base10
-  L.ident = nil
-  when defined(nimpretty):
-    L.commentOffsetA = 0
-    L.commentOffsetB = 0
-
-proc fillToken(L: var Token) =
-  L.tokType = tkInvalid
-  L.iNumber = 0
-  L.indent = 0
-  L.spacing = {}
-  setLen(L.literal, 0)
-  L.fNumber = 0.0
-  L.base = base10
-  L.ident = nil
-  when defined(nimpretty):
-    L.commentOffsetA = 0
-    L.commentOffsetB = 0
-
 proc openLexer*(lex: var Lexer, fileIdx: FileIndex, inputstream: PLLStream;
                  cache: IdentCache; config: ConfigRef) =
   openBaseLexer(lex, inputstream)
@@ -537,8 +514,8 @@ 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:
@@ -547,8 +524,8 @@ 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:
@@ -794,7 +771,7 @@ proc getString(L: var Lexer, tok: var Token, mode: StringMode) =
     if mode != normal: tok.tokType = tkRStrLit
     else: tok.tokType = tkStrLit
     while true:
-      var c = L.buf[pos]
+      let c = L.buf[pos]
       if c == '\"':
         if mode != normal and L.buf[pos+1] == '\"':
           inc(pos, 2)
@@ -820,7 +797,7 @@ proc getCharacter(L: var Lexer; tok: var Token) =
   tokenBegin(tok, L.bufpos)
   let startPos = L.bufpos
   inc(L.bufpos)               # skip '
-  var c = L.buf[L.bufpos]
+  let c = L.buf[L.bufpos]
   case c
   of '\0'..pred(' '), '\'':
     lexMessage(L, errGenerated, "invalid character literal")
@@ -938,7 +915,7 @@ proc getOperator(L: var Lexer, tok: var Token) =
   tokenBegin(tok, pos)
   var h: Hash = 0
   while true:
-    var c = L.buf[pos]
+    let c = L.buf[pos]
     if c in OpChars:
       h = h !& ord(c)
       inc(pos)
@@ -1006,22 +983,6 @@ proc getPrecedence*(tok: Token): int =
   of tkOr, tkXor, tkPtr, tkRef: result = 3
   else: return -10
 
-proc newlineFollows*(L: Lexer): bool =
-  var pos = L.bufpos
-  while true:
-    case L.buf[pos]
-    of ' ', '\t':
-      inc(pos)
-    of CR, LF:
-      result = true
-      break
-    of '#':
-      inc(pos)
-      if L.buf[pos] == '#': inc(pos)
-      if L.buf[pos] != '[': return true
-    else:
-      break
-
 proc skipMultiLineComment(L: var Lexer; tok: var Token; start: int;
                           isDoc: bool) =
   var pos = start
@@ -1113,9 +1074,7 @@ proc scanComment(L: var Lexer, tok: var Token) =
         toStrip = 0
       else:  # found first non-whitespace character
         stripInit = true
-    var lastBackslash = -1
     while L.buf[pos] notin {CR, LF, nimlexbase.EndOfFile}:
-      if L.buf[pos] == '\\': lastBackslash = pos+1
       tok.literal.add(L.buf[pos])
       inc(pos)
     tokenEndIgnore(tok, pos)
@@ -1158,7 +1117,7 @@ proc skip(L: var Lexer, tok: var Token) =
       inc(pos)
       tok.spacing.incl(tsLeading)
     of '\t':
-      if not L.allowTabs: lexMessagePos(L, errGenerated, pos, "tabs are not allowed, use spaces instead")
+      lexMessagePos(L, errGenerated, pos, "tabs are not allowed, use spaces instead")
       inc(pos)
     of CR, LF:
       tokenEndPrevious(tok, pos)
@@ -1226,7 +1185,7 @@ proc rawGetTok*(L: var Lexer, tok: var Token) =
         L.previousToken.line = tok.line.uint16
         L.previousToken.col = tok.col.int16
 
-  fillToken(tok)
+  reset(tok)
   if L.indentAhead >= 0:
     tok.indent = L.indentAhead
     L.currLineIndent = L.indentAhead
@@ -1238,7 +1197,7 @@ proc rawGetTok*(L: var Lexer, tok: var Token) =
     if tok.tokType == tkComment:
       L.indentAhead = L.currLineIndent
       return
-  var c = L.buf[L.bufpos]
+  let c = L.buf[L.bufpos]
   tok.line = L.lineNumber
   tok.col = getColNumber(L, L.bufpos)
   if c in SymStartChars - {'r', 'R'} - UnicodeOperatorStartChars:
@@ -1394,9 +1353,9 @@ proc rawGetTok*(L: var Lexer, tok: var Token) =
 
 proc getIndentWidth*(fileIdx: FileIndex, inputstream: PLLStream;
                      cache: IdentCache; config: ConfigRef): int =
-  var lex: Lexer
-  var tok: Token
-  initToken(tok)
+  result = 0
+  var lex: Lexer = default(Lexer)
+  var tok: Token = default(Token)
   openLexer(lex, fileIdx, inputstream, cache, config)
   var prevToken = tkEof
   while tok.tokType != tkEof:
@@ -1409,11 +1368,11 @@ proc getIndentWidth*(fileIdx: FileIndex, inputstream: PLLStream;
 
 proc getPrecedence*(ident: PIdent): int =
   ## assumes ident is binary operator already
-  var tok: Token
-  initToken(tok)
-  tok.ident = ident
-  tok.tokType =
-    if tok.ident.id in ord(tokKeywordLow) - ord(tkSymbol)..ord(tokKeywordHigh) - ord(tkSymbol):
-      TokType(tok.ident.id + ord(tkSymbol))
-    else: tkOpr
+  let
+    tokType =
+      if ident.id in ord(tokKeywordLow) - ord(tkSymbol)..ord(tokKeywordHigh) - ord(tkSymbol):
+        TokType(ident.id + ord(tkSymbol))
+      else: tkOpr
+    tok = Token(ident: ident, tokType: tokType)
+
   getPrecedence(tok)

compiler/liftdestructors.nim

@@ -11,8 +11,9 @@
 ## (`=sink`, `=copy`, `=destroy`, `=deepCopy`, `=wasMoved`, `=dup`).
 
 import modulegraphs, lineinfos, idents, ast, renderer, semdata,
-  sighashes, lowerings, options, types, msgs, magicsys, tables, ccgutils
+  sighashes, lowerings, options, types, msgs, magicsys, ccgutils
 
+import std/tables
 from trees import isCaseObj
 
 when defined(nimPreviewSlimSystem):
@@ -162,8 +163,7 @@ proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool)
     if c.filterDiscriminator != nil: return
     let f = n.sym
     let b = if c.kind == attachedTrace: y else: y.dotField(f)
-    if (sfCursor in f.flags and f.typ.skipTypes(abstractInst).kind in {tyRef, tyProc} and
-        c.g.config.selectedGC in {gcArc, gcAtomicArc, 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:
@@ -302,7 +302,7 @@ 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
@@ -367,6 +367,8 @@ proc considerAsgnOrSink(c: var TLiftCtx; t: PType; body, x, y: PNode;
       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):
@@ -396,6 +398,8 @@ 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})
@@ -435,6 +439,8 @@ 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)
@@ -455,6 +461,8 @@ 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)
@@ -469,6 +477,8 @@ 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)
@@ -483,6 +493,8 @@ proc considerUserDefinedOp(c: var TLiftCtx; t: PType; body, x, y: PNode): bool =
       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), c.idgen, c.fn, c.info)
@@ -542,6 +554,14 @@ 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:
@@ -549,10 +569,13 @@ proc fillSeqOp(c: var TLiftCtx; t: PType; body, x, y: PNode) =
     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:
@@ -1012,7 +1035,7 @@ 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;
@@ -1034,7 +1057,7 @@ proc symDupPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttache
   res.typ = typ
   src.typ = typ
 
-  result.typ = newType(tyProc, nextTypeId idgen, owner)
+  result.typ = newType(tyProc, idgen, owner)
   result.typ.n = newNodeI(nkFormalParams, info)
   rawAddSon(result.typ, res.typ)
   result.typ.n.add newNodeI(nkEffectList, info)
@@ -1059,7 +1082,7 @@ proc symDupPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttache
   incl result.flags, sfGeneratedOp
 
 proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator): PSym =
+              info: TLineInfo; idgen: IdGenerator; isDiscriminant = false): PSym =
   if kind == attachedDup:
     return symDupPrototype(g, typ, owner, kind, info, idgen)
 
@@ -1069,7 +1092,8 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
   let src = newSym(skParam, getIdent(g.cache, if kind == attachedTrace: "env" else: "src"),
                    idgen, result, info)
 
-  if kind == attachedDestructor and typ.kind in {tyRef, tyString, tySequence} and g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
+  if kind == attachedDestructor and g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc} and
+     ((g.config.isDefined("nimPreviewNonVarDestructor") and not isDiscriminant) or typ.kind in {tyRef, tyString, tySequence}):
     dest.typ = typ
   else:
     dest.typ = makeVarType(typ.owner, typ, idgen)
@@ -1079,7 +1103,7 @@ proc symPrototype(g: ModuleGraph; typ: PType; owner: PSym; kind: TTypeAttachedOp
   else:
     src.typ = typ
 
-  result.typ = newProcType(info, nextTypeId(idgen), owner)
+  result.typ = newProcType(info, idgen, owner)
   result.typ.addParam dest
   if kind notin {attachedDestructor, attachedWasMoved}:
     result.typ.addParam src
@@ -1162,7 +1186,8 @@ proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
 proc produceDestructorForDiscriminator*(g: ModuleGraph; typ: PType; field: PSym,
                                         info: TLineInfo; idgen: IdGenerator): PSym =
   assert(typ.skipTypes({tyAlias, tyGenericInst}).kind == tyObject)
-  result = symPrototype(g, field.typ, typ.owner, attachedDestructor, info, idgen)
+  # discrimantor assignments needs pointers to destroy fields; alas, we cannot use non-var destructor here
+  result = symPrototype(g, field.typ, typ.owner, attachedDestructor, info, idgen, isDiscriminant = true)
   var a = TLiftCtx(info: info, g: g, kind: attachedDestructor, asgnForType: typ, idgen: idgen,
                    fn: result)
   a.asgnForType = typ
@@ -1249,7 +1274,7 @@ proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInf
   # bug #15122: We need to produce all prototypes before entering the
   # mind boggling recursion. Hacks like these imply we should rewrite
   # this module.
-  var generics: array[attachedWasMoved..attachedTrace, bool]
+  var generics: array[attachedWasMoved..attachedTrace, bool] = default(array[attachedWasMoved..attachedTrace, bool])
   for k in attachedWasMoved..lastAttached:
     generics[k] = getAttachedOp(g, canon, k) != nil
     if not generics[k]:

compiler/liftlocals.nim

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

compiler/lineinfos.nim

@@ -7,10 +7,11 @@
 #    distribution, for details about the copyright.
 #
 
-## This module contains the ``TMsgKind`` enum as well as the
-## ``TLineInfo`` object.
+## This module contains the `TMsgKind` enum as well as the
+## `TLineInfo` object.
 
-import ropes, tables, pathutils, hashes
+import ropes, pathutils
+import std/[hashes, tables]
 
 const
   explanationsBaseUrl* = "https://nim-lang.github.io/Nim"
@@ -91,6 +92,7 @@ type
     warnStmtListLambda = "StmtListLambda",
     warnBareExcept = "BareExcept",
     warnImplicitDefaultValue = "ImplicitDefaultValue",
+    warnStdPrefix = "StdPrefix"
     warnUser = "User",
     # hints
     hintSuccess = "Success", hintSuccessX = "SuccessX",
@@ -104,10 +106,10 @@ type
     hintPattern = "Pattern", hintExecuting = "Exec", hintLinking = "Link", hintDependency = "Dependency",
     hintSource = "Source", hintPerformance = "Performance", hintStackTrace = "StackTrace",
     hintGCStats = "GCStats", hintGlobalVar = "GlobalVar", hintExpandMacro = "ExpandMacro",
-    hintAmbiguousEnum = "AmbiguousEnum",
     hintUser = "User", hintUserRaw = "UserRaw", hintExtendedContext = "ExtendedContext",
     hintMsgOrigin = "MsgOrigin", # since 1.3.5
     hintDeclaredLoc = "DeclaredLoc", # since 1.5.1
+    hintUnknownHint = "UnknownHint"
 
 const
   MsgKindToStr*: array[TMsgKind, string] = [
@@ -185,7 +187,7 @@ const
     warnAnyEnumConv: "$1",
     warnHoleEnumConv: "$1",
     warnCstringConv: "$1",
-    warnPtrToCstringConv: "unsafe conversion to 'cstring' from '$1'; this will become a compile time error in the future",
+    warnPtrToCstringConv: "unsafe conversion to 'cstring' from '$1'; Use a `cast` operation like `cast[cstring](x)`; this will become a compile time error in the future",
     warnEffect: "$1",
     warnCastSizes: "$1", # deadcode
     warnAboveMaxSizeSet: "$1",
@@ -194,6 +196,7 @@ const
     warnStmtListLambda: "statement list expression assumed to be anonymous proc; this is deprecated, use `do (): ...` or `proc () = ...` instead",
     warnBareExcept: "$1",
     warnImplicitDefaultValue: "$1",
+    warnStdPrefix: "$1 needs the 'std' prefix",
     warnUser: "$1",
     hintSuccess: "operation successful: $#",
     # keep in sync with `testament.isSuccess`
@@ -225,12 +228,12 @@ const
     hintGCStats: "$1",
     hintGlobalVar: "global variable declared here",
     hintExpandMacro: "expanded macro: $1",
-    hintAmbiguousEnum: "$1",
     hintUser: "$1",
     hintUserRaw: "$1",
     hintExtendedContext: "$1",
     hintMsgOrigin: "$1",
     hintDeclaredLoc: "$1",
+    hintUnknownHint: "unknown hint: $1"
   ]
 
 const
@@ -248,7 +251,8 @@ type
   TNoteKinds* = set[TNoteKind]
 
 proc computeNotesVerbosity(): array[0..3, TNoteKinds] =
-  result[3] = {low(TNoteKind)..high(TNoteKind)} - {warnObservableStores, warnResultUsed, warnAnyEnumConv, warnBareExcept}
+  result = default(array[0..3, TNoteKinds])
+  result[3] = {low(TNoteKind)..high(TNoteKind)} - {warnObservableStores, warnResultUsed, warnAnyEnumConv, warnBareExcept, warnStdPrefix}
   result[2] = result[3] - {hintStackTrace, hintExtendedContext, hintDeclaredLoc, hintProcessingStmt}
   result[1] = result[2] - {warnProveField, warnProveIndex,
     warnGcUnsafe, hintPath, hintDependency, hintCodeBegin, hintCodeEnd,
@@ -310,7 +314,7 @@ 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
@@ -341,9 +345,8 @@ 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
 

compiler/llstream.nim

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

compiler/lookups.nim

@@ -14,8 +14,10 @@ when defined(nimPreviewSlimSystem):
   import std/assertions
 
 import
-  intsets, ast, astalgo, idents, semdata, types, msgs, options,
-  renderer, lineinfos, modulegraphs, astmsgs, sets, wordrecg
+  ast, astalgo, idents, semdata, types, msgs, options,
+  renderer, lineinfos, modulegraphs, astmsgs, wordrecg
+
+import std/[intsets, sets]
 
 proc ensureNoMissingOrUnusedSymbols(c: PContext; scope: PScope)
 
@@ -72,7 +74,7 @@ proc addUniqueSym*(scope: PScope, s: PSym): PSym =
 
 proc openScope*(c: PContext): PScope {.discardable.} =
   result = PScope(parent: c.currentScope,
-                  symbols: newStrTable(),
+                  symbols: initStrTable(),
                   depthLevel: c.scopeDepth + 1)
   c.currentScope = result
 
@@ -254,6 +256,41 @@ 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
@@ -298,7 +335,7 @@ 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
@@ -404,7 +441,7 @@ 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) =
@@ -429,7 +466,7 @@ proc mergeShadowScope*(c: PContext) =
       c.addInterfaceDecl(sym)
 
 
-import std/editdistance, heapqueue
+import std/[editdistance, heapqueue]
 
 type SpellCandidate = object
   dist: int
@@ -458,7 +495,7 @@ 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)
 
@@ -488,6 +525,7 @@ 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"
@@ -560,7 +598,7 @@ proc lookUp*(c: PContext, n: PNode): PSym =
     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)
@@ -586,6 +624,8 @@ proc qualifiedLookUp*(c: PContext, n: PNode, flags: set[TLookupFlag]): PSym =
         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:
@@ -641,6 +681,7 @@ 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
@@ -664,6 +705,7 @@ 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:
@@ -693,7 +735,7 @@ 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)
 
@@ -708,6 +750,7 @@ 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
@@ -720,6 +763,7 @@ 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)
@@ -782,6 +826,8 @@ proc nextOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
           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)
@@ -805,13 +851,16 @@ proc nextOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
       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

@@ -122,25 +122,6 @@ 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, "_"), 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(nkTupleClassTy, 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 :-(
@@ -163,7 +144,7 @@ proc lowerSwap*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PNod
   result.add newFastAsgnStmt(n[2], tempAsNode)
 
 proc createObj*(g: ModuleGraph; idgen: IdGenerator; owner: PSym, info: TLineInfo; final=true): PType =
-  result = newType(tyObject, nextTypeId(idgen), owner)
+  result = newType(tyObject, idgen, owner)
   if final:
     rawAddSon(result, nil)
     incl result.flags, tfFinal
@@ -237,6 +218,9 @@ proc addField*(obj: PType; s: PSym; cache: IdentCache; idgen: IdGenerator): PSym
   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
@@ -336,7 +320,7 @@ proc indirectAccess*(a, b: PSym, info: TLineInfo): PNode =
 proc genAddrOf*(n: PNode; idgen: IdGenerator; typeKind = tyPtr): PNode =
   result = newNodeI(nkAddr, n.info, 1)
   result[0] = n
-  result.typ = newType(typeKind, nextTypeId(idgen), n.typ.owner)
+  result.typ = newType(typeKind, idgen, n.typ.owner)
   result.typ.rawAddSon(n.typ)
 
 proc genDeref*(n: PNode; k = nkHiddenDeref): PNode =

compiler/magicsys.nim

@@ -18,7 +18,7 @@ export createMagic
 proc nilOrSysInt*(g: ModuleGraph): PType = g.sysTypes[tyInt]
 
 proc newSysType(g: ModuleGraph; kind: TTypeKind, size: int): PType =
-  result = newType(kind, nextTypeId(g.idgen), g.systemModule)
+  result = newType(kind, g.idgen, g.systemModule)
   result.size = size
   result.align = size.int16
 
@@ -27,9 +27,10 @@ proc getSysSym*(g: ModuleGraph; info: TLineInfo; name: string): PSym =
   if result == nil:
     localError(g.config, info, "system module needs: " & name)
     result = newSym(skError, getIdent(g.cache, name), g.idgen, g.systemModule, g.systemModule.info, {})
-    result.typ = newType(tyError, nextTypeId(g.idgen), g.systemModule)
+    result.typ = newType(tyError, g.idgen, g.systemModule)
 
 proc getSysMagic*(g: ModuleGraph; info: TLineInfo; name: string, m: TMagic): PSym =
+  result = nil
   let id = getIdent(g.cache, name)
   for r in systemModuleSyms(g, id):
     if r.magic == m:
@@ -39,7 +40,7 @@ proc getSysMagic*(g: ModuleGraph; info: TLineInfo; name: string, m: TMagic): PSy
   if result != nil: return result
   localError(g.config, info, "system module needs: " & name)
   result = newSym(skError, id, g.idgen, g.systemModule, g.systemModule.info, {})
-  result.typ = newType(tyError, nextTypeId(g.idgen), g.systemModule)
+  result.typ = newType(tyError, g.idgen, g.systemModule)
 
 proc sysTypeFromName*(g: ModuleGraph; info: TLineInfo; name: string): PType =
   result = getSysSym(g, info, name).typ
@@ -80,8 +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
 
@@ -92,16 +93,23 @@ proc getFloatLitType*(g: ModuleGraph; literal: PNode): PType =
 
 proc skipIntLit*(t: PType; id: IdGenerator): PType {.inline.} =
   if t.n != nil and t.kind in {tyInt, tyFloat}:
-    result = copyType(t, nextTypeId(id), t.owner)
+    result = copyType(t, id, t.owner)
     result.n = nil
   else:
     result = t
 
 proc addSonSkipIntLit*(father, son: PType; id: IdGenerator) =
   let s = son.skipIntLit(id)
-  father.sons.add(s)
+  father.add(s)
   propagateToOwner(father, s)
 
+proc makeVarType*(owner: PSym; baseType: PType; idgen: IdGenerator; kind = tyVar): PType =
+  if baseType.kind == kind:
+    result = baseType
+  else:
+    result = newType(kind, idgen, owner)
+    addSonSkipIntLit(result, baseType, idgen)
+
 proc getCompilerProc*(g: ModuleGraph; name: string): PSym =
   let ident = getIdent(g.cache, name)
   result = strTableGet(g.compilerprocs, ident)
@@ -123,7 +131,7 @@ proc registerNimScriptSymbol*(g: ModuleGraph; s: PSym) =
 proc getNimScriptSymbol*(g: ModuleGraph; name: string): PSym =
   strTableGet(g.exposed, getIdent(g.cache, name))
 
-proc resetNimScriptSymbols*(g: ModuleGraph) = initStrTable(g.exposed)
+proc resetNimScriptSymbols*(g: ModuleGraph) = g.exposed = initStrTable()
 
 proc getMagicEqSymForType*(g: ModuleGraph; t: PType; info: TLineInfo): PSym =
   case t.kind
@@ -145,7 +153,17 @@ proc getMagicEqSymForType*(g: ModuleGraph; t: PType; info: TLineInfo): PSym =
   of tyProc:
     result = getSysMagic(g, info, "==", mEqProc)
   else:
+    result = nil
     globalError(g.config, info,
       "can't find magic equals operator for type kind " & $t.kind)
 
+proc makePtrType*(baseType: PType; idgen: IdGenerator): PType =
+  result = newType(tyPtr, idgen, baseType.owner)
+  addSonSkipIntLit(result, baseType, idgen)
 
+proc makeAddr*(n: PNode; idgen: IdGenerator): PNode =
+  if n.kind == nkHiddenAddr:
+    result = n
+  else:
+    result = newTree(nkHiddenAddr, n)
+    result.typ = makePtrType(n.typ, idgen)

compiler/main.nim

@@ -22,12 +22,13 @@ import
   modules,
   modulegraphs, lineinfos, pathutils, vmprofiler
 
+# ensure NIR compiles:
+import nir / nir
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions]
 
-import ic / [cbackend, integrity, navigator]
-from ic / ic import rodViewer
+import ic / [cbackend, integrity, navigator, ic]
 
 import ../dist/checksums/src/checksums/sha1
 
@@ -47,6 +48,9 @@ proc writeDepsFile(g: ModuleGraph) =
       f.writeLine(toFullPath(g.config, k))
   f.close()
 
+proc writeNinjaFile(g: ModuleGraph) =
+  discard "to implement"
+
 proc writeCMakeDepsFile(conf: ConfigRef) =
   ## write a list of C files for build systems like CMake.
   ## only updated when the C file list changes.
@@ -56,7 +60,7 @@ proc writeCMakeDepsFile(conf: ConfigRef) =
   for it in conf.toCompile: cfiles.add(it.cname.string)
   let fileset = cfiles.toCountTable()
   # read old cfiles list
-  var fl: File
+  var fl: File = default(File)
   var prevset = initCountTable[string]()
   if open(fl, fname.string, fmRead):
     for line in fl.lines: prevset.inc(line)
@@ -115,7 +119,7 @@ when not defined(leanCompiler):
       setPipeLinePass(graph, Docgen2JsonPass)
     of HtmlExt:
       setPipeLinePass(graph, Docgen2Pass)
-    else: doAssert false, $ext
+    else: raiseAssert $ext
     compilePipelineProject(graph)
 
 proc commandCompileToC(graph: ModuleGraph) =
@@ -157,6 +161,26 @@ proc commandCompileToC(graph: ModuleGraph) =
     if optGenCDeps in graph.config.globalOptions:
       writeCMakeDepsFile(conf)
 
+proc commandCompileToNir(graph: ModuleGraph) =
+  let conf = graph.config
+  extccomp.initVars(conf)
+  if conf.symbolFiles == disabledSf:
+    if {optRun, optForceFullMake} * conf.globalOptions == {optRun}:
+      if not changeDetectedViaJsonBuildInstructions(conf, conf.jsonBuildInstructionsFile):
+        # nothing changed
+        graph.config.notes = graph.config.mainPackageNotes
+        return
+
+  if not extccomp.ccHasSaneOverflow(conf):
+    conf.symbols.defineSymbol("nimEmulateOverflowChecks")
+
+  if conf.symbolFiles == disabledSf:
+    setPipeLinePass(graph, NirPass)
+  else:
+    setPipeLinePass(graph, SemPass)
+  compilePipelineProject(graph)
+  writeNinjaFile(graph)
+
 proc commandJsonScript(graph: ModuleGraph) =
   extccomp.runJsonBuildInstructions(graph.config, graph.config.jsonBuildInstructionsFile)
 
@@ -173,13 +197,16 @@ proc commandCompileToJS(graph: ModuleGraph) =
     if optGenScript in conf.globalOptions:
       writeDepsFile(graph)
 
-proc commandInteractive(graph: ModuleGraph) =
+proc commandInteractive(graph: ModuleGraph; useNir: bool) =
   graph.config.setErrorMaxHighMaybe
   initDefines(graph.config.symbols)
-  defineSymbol(graph.config.symbols, "nimscript")
+  if useNir:
+    defineSymbol(graph.config.symbols, "noSignalHandler")
+  else:
+    defineSymbol(graph.config.symbols, "nimscript")
   # note: seems redundant with -d:nimHasLibFFI
   when hasFFI: defineSymbol(graph.config.symbols, "nimffi")
-  setPipeLinePass(graph, InterpreterPass)
+  setPipeLinePass(graph, if useNir: NirReplPass else: InterpreterPass)
   compilePipelineSystemModule(graph)
   if graph.config.commandArgs.len > 0:
     discard graph.compilePipelineModule(fileInfoIdx(graph.config, graph.config.projectFull), {})
@@ -196,8 +223,7 @@ proc commandScan(cache: IdentCache, config: ConfigRef) =
   if stream != nil:
     var
       L: Lexer
-      tok: Token
-    initToken(tok)
+      tok: Token = default(Token)
     openLexer(L, f, stream, cache, config)
     while true:
       rawGetTok(L, tok)
@@ -267,7 +293,9 @@ proc mainCommand*(graph: ModuleGraph) =
         # and it has added this define implictly, so we must undo that here.
         # A better solution might be to fix system.nim
         undefSymbol(conf.symbols, "useNimRtl")
-    of backendInvalid: doAssert false
+    of backendNir:
+      if conf.exc == excNone: conf.exc = excGoto
+    of backendInvalid: raiseAssert "unreachable"
 
   proc compileToBackend() =
     customizeForBackend(conf.backend)
@@ -277,7 +305,8 @@ proc mainCommand*(graph: ModuleGraph) =
     of backendCpp: commandCompileToC(graph)
     of backendObjc: commandCompileToC(graph)
     of backendJs: commandCompileToJS(graph)
-    of backendInvalid: doAssert false
+    of backendNir: commandCompileToNir(graph)
+    of backendInvalid: raiseAssert "unreachable"
 
   template docLikeCmd(body) =
     when defined(leanCompiler):
@@ -304,7 +333,10 @@ proc mainCommand*(graph: ModuleGraph) =
 
   ## process all commands
   case conf.cmd
-  of cmdBackends: compileToBackend()
+  of cmdBackends:
+    compileToBackend()
+    when BenchIC:
+      echoTimes graph.packed
   of cmdTcc:
     when hasTinyCBackend:
       extccomp.setCC(conf, "tcc", unknownLineInfo)
@@ -400,6 +432,10 @@ proc mainCommand*(graph: ModuleGraph) =
       for it in conf.searchPaths: msgWriteln(conf, it.string)
   of cmdCheck:
     commandCheck(graph)
+  of cmdM:
+    graph.config.symbolFiles = v2Sf
+    setUseIc(graph.config.symbolFiles != disabledSf)
+    commandCheck(graph)
   of cmdParse:
     wantMainModule(conf)
     discard parseFile(conf.projectMainIdx, cache, conf)
@@ -407,7 +443,7 @@ proc mainCommand*(graph: ModuleGraph) =
     wantMainModule(conf)
     commandView(graph)
     #msgWriteln(conf, "Beware: Indentation tokens depend on the parser's state!")
-  of cmdInteractive: commandInteractive(graph)
+  of cmdInteractive: commandInteractive(graph, isDefined(conf, "nir"))
   of cmdNimscript:
     if conf.projectIsCmd or conf.projectIsStdin: discard
     elif not fileExists(conf.projectFull):

compiler/modulegraphs.nim

@@ -11,11 +11,12 @@
 ## represents a complete Nim project. Single modules can either be kept in RAM
 ## or stored in a rod-file.
 
-import intsets, tables, hashes
+import std/[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]
 
+
 when defined(nimPreviewSlimSystem):
   import std/assertions
 
@@ -57,6 +58,7 @@ type
   SymInfoPair* = object
     sym*: PSym
     info*: TLineInfo
+    isDecl*: bool
 
   PipelinePass* = enum
     NonePass
@@ -65,6 +67,8 @@ type
     CgenPass
     EvalPass
     InterpreterPass
+    NirPass
+    NirReplPass
     GenDependPass
     Docgen2TexPass
     Docgen2JsonPass
@@ -78,8 +82,9 @@ type
     typeInstCache*: Table[ItemId, seq[LazyType]] # A symbol's ItemId.
     procInstCache*: Table[ItemId, seq[LazyInstantiation]] # A symbol's ItemId.
     attachedOps*: array[TTypeAttachedOp, Table[ItemId, LazySym]] # Type ID, destructors, etc.
-    methodsPerType*: Table[ItemId, seq[(int, LazySym)]] # Type ID, attached methods
-    memberProcsPerType*: Table[ItemId, seq[PSym]] # Type ID, attached member procs (only c++, virtual and ctor so far)
+    methodsPerGenericType*: Table[ItemId, seq[(int, LazySym)]] # Type ID, attached methods
+    memberProcsPerType*: Table[ItemId, seq[PSym]] # Type ID, attached member procs (only c++, virtual,member and ctor so far).
+    initializersPerType*: Table[ItemId, PNode] # Type ID, AST call to the default ctor (c++ only)
     enumToStringProcs*: Table[ItemId, LazySym]
     emittedTypeInfo*: Table[string, FileIndex]
 
@@ -89,6 +94,7 @@ type
     importDeps*: Table[FileIndex, seq[FileIndex]] # explicit import module dependencies
     suggestMode*: bool # whether we are in nimsuggest mode or not.
     invalidTransitiveClosure: bool
+    interactive*: bool
     inclToMod*: Table[FileIndex, FileIndex] # mapping of include file to the
                                             # first module that included it
     importStack*: seq[FileIndex]  # The current import stack. Used for detecting recursive
@@ -98,12 +104,18 @@ type
     cache*: IdentCache
     vm*: RootRef # unfortunately the 'vm' state is shared project-wise, this will
                  # be clarified in later compiler implementations.
+    repl*: RootRef # REPL state is shared project-wise.
     doStopCompile*: proc(): bool {.closure.}
     usageSym*: PSym # for nimsuggest
     owners*: seq[PSym]
     suggestSymbols*: Table[FileIndex, seq[SymInfoPair]]
     suggestErrors*: Table[FileIndex, seq[Suggest]]
     methods*: seq[tuple[methods: seq[PSym], dispatcher: PSym]] # needs serialization!
+    bucketTable*: CountTable[ItemId]
+    objectTree*: Table[ItemId, seq[tuple[depth: int, value: PType]]]
+    methodsPerType*: Table[ItemId, seq[LazySym]]
+    dispatchers*: seq[LazySym]
+
     systemModule*: PSym
     sysTypes*: array[TTypeKind, PType]
     compilerprocs*: TStrTable
@@ -142,13 +154,15 @@ type
                  isFrontend: bool]
 
 proc resetForBackend*(g: ModuleGraph) =
-  initStrTable(g.compilerprocs)
+  g.compilerprocs = initStrTable()
   g.typeInstCache.clear()
   g.procInstCache.clear()
   for a in mitems(g.attachedOps):
     a.clear()
-  g.methodsPerType.clear()
+  g.methodsPerGenericType.clear()
   g.enumToStringProcs.clear()
+  g.dispatchers.setLen(0)
+  g.methodsPerType.clear()
 
 const
   cb64 = [
@@ -196,8 +210,8 @@ 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)
@@ -206,10 +220,10 @@ proc strTableAdds*(g: ModuleGraph, m: PSym, s: PSym) =
 proc isCachedModule(g: ModuleGraph; module: int): bool {.inline.} =
   result = module < g.packed.len and g.packed[module].status == loaded
 
-proc isCachedModule(g: ModuleGraph; m: PSym): bool {.inline.} =
+proc isCachedModule*(g: ModuleGraph; m: PSym): bool {.inline.} =
   isCachedModule(g, m.position)
 
-proc simulateCachedModule*(g: ModuleGraph; moduleSym: PSym; m: PackedModule) =
+proc simulateCachedModule(g: ModuleGraph; moduleSym: PSym; m: PackedModule) =
   when false:
     echo "simulating ", moduleSym.name.s, " ", moduleSym.position
   simulateLoadedModule(g.packed, g.config, g.cache, moduleSym, m)
@@ -319,6 +333,7 @@ iterator procInstCacheItems*(g: ModuleGraph; s: PSym): PInstantiation =
     for t in mitems(x[]):
       yield resolveInst(g, t)
 
+
 proc getAttachedOp*(g: ModuleGraph; t: PType; op: TTypeAttachedOp): PSym =
   ## returns the requested attached operation for type `t`. Can return nil
   ## if no such operation exists.
@@ -342,6 +357,27 @@ proc completePartialOp*(g: ModuleGraph; module: int; t: PType; op: TTypeAttached
     toPackedGeneratedProcDef(value, g.encoders[module], g.packed[module].fromDisk)
     #storeAttachedProcDef(t, op, value, g.encoders[module], g.packed[module].fromDisk)
 
+iterator getDispatchers*(g: ModuleGraph): PSym =
+  for i in g.dispatchers.mitems:
+    yield resolveSym(g, i)
+
+proc addDispatchers*(g: ModuleGraph, value: PSym) =
+  # TODO: add it for packed modules
+  g.dispatchers.add LazySym(sym: value)
+
+iterator resolveLazySymSeq(g: ModuleGraph, list: var seq[LazySym]): PSym =
+  for it in list.mitems:
+    yield resolveSym(g, it)
+
+proc setMethodsPerType*(g: ModuleGraph; id: ItemId, methods: seq[LazySym]) =
+  # TODO: add it for packed modules
+  g.methodsPerType[id] = methods
+
+iterator getMethodsPerType*(g: ModuleGraph; t: PType): PSym =
+  if g.methodsPerType.contains(t.itemId):
+    for it in mitems g.methodsPerType[t.itemId]:
+      yield resolveSym(g, it)
+
 proc getToStringProc*(g: ModuleGraph; t: PType): PSym =
   result = resolveSym(g, g.enumToStringProcs[t.itemId])
   assert result != nil
@@ -350,12 +386,12 @@ proc setToStringProc*(g: ModuleGraph; t: PType; value: PSym) =
   g.enumToStringProcs[t.itemId] = LazySym(sym: value)
 
 iterator methodsForGeneric*(g: ModuleGraph; t: PType): (int, PSym) =
-  if g.methodsPerType.contains(t.itemId):
-    for it in mitems g.methodsPerType[t.itemId]:
+  if g.methodsPerGenericType.contains(t.itemId):
+    for it in mitems g.methodsPerGenericType[t.itemId]:
       yield (it[0], resolveSym(g, it[1]))
 
 proc addMethodToGeneric*(g: ModuleGraph; module: int; t: PType; col: int; m: PSym) =
-  g.methodsPerType.mgetOrPut(t.itemId, @[]).add (col, LazySym(sym: m))
+  g.methodsPerGenericType.mgetOrPut(t.itemId, @[]).add (col, LazySym(sym: m))
 
 proc hasDisabledAsgn*(g: ModuleGraph; t: PType): bool =
   let op = getAttachedOp(g, t, attachedAsgn)
@@ -368,10 +404,11 @@ proc copyTypeProps*(g: ModuleGraph; module: int; dest, src: PType) =
       setAttachedOp(g, module, dest, k, op)
 
 proc loadCompilerProc*(g: ModuleGraph; name: string): PSym =
+  result = nil
   if g.config.symbolFiles == disabledSf: return nil
 
   # slow, linear search, but the results are cached:
-  for module in 0..high(g.packed):
+  for module in 0..<len(g.packed):
     #if isCachedModule(g, module):
     let x = searchForCompilerproc(g.packed[module], name)
     if x >= 0:
@@ -428,7 +465,7 @@ proc registerModule*(g: ModuleGraph; m: PSym) =
     setLen(g.ifaces, m.position + 1)
 
   if m.position >= g.packed.len:
-    setLen(g.packed, m.position + 1)
+    setLen(g.packed.pm, m.position + 1)
 
   g.ifaces[m.position] = Iface(module: m, converters: @[], patterns: @[],
                                uniqueName: rope(uniqueModuleName(g.config, FileIndex(m.position))))
@@ -458,7 +495,7 @@ 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 = @[]
@@ -468,9 +505,9 @@ 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]()
@@ -487,7 +524,7 @@ proc newModuleGraph*(cache: IdentCache; config: ConfigRef): ModuleGraph =
   initModuleGraphFields(result)
 
 proc resetAllModules*(g: ModuleGraph) =
-  initStrTable(g.packageSyms)
+  g.packageSyms = initStrTable()
   g.deps = initIntSet()
   g.ifaces = @[]
   g.importStack = @[]
@@ -495,11 +532,12 @@ proc resetAllModules*(g: ModuleGraph) =
   g.usageSym = nil
   g.owners = @[]
   g.methods = @[]
-  initStrTable(g.compilerprocs)
-  initStrTable(g.exposed)
+  g.compilerprocs = initStrTable()
+  g.exposed = initStrTable()
   initModuleGraphFields(g)
 
 proc getModule*(g: ModuleGraph; fileIdx: FileIndex): PSym =
+  result = nil
   if fileIdx.int32 >= 0:
     if isCachedModule(g, fileIdx.int32):
       result = g.packed[fileIdx.int32].module
@@ -579,6 +617,7 @@ proc markDirty*(g: ModuleGraph; fileIdx: FileIndex) =
   if m != nil:
     g.suggestSymbols.del(fileIdx)
     g.suggestErrors.del(fileIdx)
+    g.resetForBackend
     incl m.flags, sfDirty
 
 proc unmarkAllDirty*(g: ModuleGraph) =
@@ -605,6 +644,7 @@ proc markClientsDirty*(g: ModuleGraph; fileIdx: FileIndex) =
 
 proc needsCompilation*(g: ModuleGraph): bool =
   # every module that *depends* on this file is also dirty:
+  result = false
   for i in 0i32..<g.ifaces.len.int32:
     let m = g.ifaces[i].module
     if m != nil:
@@ -612,6 +652,7 @@ proc needsCompilation*(g: ModuleGraph): bool =
         return true
 
 proc needsCompilation*(g: ModuleGraph, fileIdx: FileIndex): bool =
+  result = false
   let module = g.getModule(fileIdx)
   if module != nil and g.isDirty(module):
     return true
@@ -633,6 +674,8 @@ proc moduleFromRodFile*(g: ModuleGraph; fileIdx: FileIndex;
   ## Returns 'nil' if the module needs to be recompiled.
   if g.config.symbolFiles in {readOnlySf, v2Sf, stressTest}:
     result = moduleFromRodFile(g.packed, g.config, g.cache, fileIdx, cachedModules)
+  else:
+    result = nil
 
 proc configComplete*(g: ModuleGraph) =
   rememberStartupConfig(g.startupPackedConfig, g.config)

compiler/modulepaths.nim

@@ -7,9 +7,11 @@
 #    distribution, for details about the copyright.
 #
 
-import ast, renderer, strutils, msgs, options, idents, os, lineinfos,
+import ast, renderer, msgs, options, idents, lineinfos,
   pathutils
 
+import std/[strutils, os]
+
 proc getModuleName*(conf: ConfigRef; n: PNode): string =
   # This returns a short relative module name without the nim extension
   # e.g. like "system", "importer" or "somepath/module"

compiler/msgs.nim

@@ -60,6 +60,22 @@ proc makeCString*(s: string): Rope =
     toCChar(s[i], result)
   result.add('\"')
 
+proc makeCCharArray*(s: string): Rope =
+  result = newStringOfCap(int(s.len.toFloat * 1.1) + 1)
+  result.add("{")
+  for i in 0..<s.len:
+    # line wrapping of string litterals in cgen'd code was a bad idea, e.g. causes: bug #16265
+    # It also makes reading c sources or grepping harder, for zero benefit.
+    # const MaxLineLength = 64
+    # if (i + 1) mod MaxLineLength == 0:
+    #   res.add("\"\L\"")
+    if i != 0:
+      result.add ", "
+    result.add '\''
+    toCChar(s[i], result)
+    result.add '\''
+  result.add('}')
+
 proc newFileInfo(fullPath: AbsoluteFile, projPath: RelativeFile): TFileInfo =
   result.fullPath = fullPath
   #shallow(result.fullPath)
@@ -294,9 +310,11 @@ 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 +426,7 @@ 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 +520,8 @@ 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
@@ -721,6 +741,8 @@ proc genSuccessX*(conf: ConfigRef) =
   elif conf.outFile.isEmpty and conf.cmd notin {cmdJsonscript} + cmdDocLike + cmdBackends:
     # for some cmd we expect a valid absOutFile
     output = "unknownOutput"
+  elif optStdout in conf.globalOptions:
+    output = "stdout"
   else:
     output = $conf.absOutFile
   if conf.filenameOption != foAbs: output = output.AbsoluteFile.extractFilename

compiler/nilcheck.nim

@@ -7,8 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
-import ast, renderer, intsets, tables, msgs, options, lineinfos, strformat, idents, treetab, hashes
-import sequtils, strutils, sets
+import ast, renderer, msgs, options, lineinfos, idents, treetab
+import std/[intsets, tables, sequtils, strutils, sets, strformat, hashes]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions
@@ -309,6 +309,7 @@ proc symbol(n: PNode): Symbol =
   # echo "symbol ", n, " ", n.kind, " ", result.int
 
 func `$`(map: NilMap): string =
+  result = ""
   var now = map
   var stack: seq[NilMap] = @[]
   while not now.isNil:
@@ -416,7 +417,7 @@ proc moveOut(ctx: NilCheckerContext, map: NilMap, target: PNode) =
   if targetSetIndex != noSetIndex:
     var targetSet = map.sets[targetSetIndex]
     if targetSet.len > 1:
-      var other: ExprIndex
+      var other: ExprIndex = default(ExprIndex)
 
       for element in targetSet:
         if element.ExprIndex != targetIndex:
@@ -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)
@@ -916,7 +918,7 @@ proc infix(ctx: NilCheckerContext, l: PNode, r: PNode, magic: TMagic): PNode =
     newSymNode(op, r.info),
     l,
     r)
-  result.typ = newType(tyBool, nextTypeId ctx.idgen, nil)
+  result.typ = newType(tyBool, ctx.idgen, nil)
 
 proc prefixNot(ctx: NilCheckerContext, node: PNode): PNode =
   var cache = newIdentCache()
@@ -926,7 +928,7 @@ proc prefixNot(ctx: NilCheckerContext, node: PNode): PNode =
   result = nkPrefix.newTree(
     newSymNode(op, node.info),
     node)
-  result.typ = newType(tyBool, nextTypeId ctx.idgen, nil)
+  result.typ = newType(tyBool, ctx.idgen, nil)
 
 proc infixEq(ctx: NilCheckerContext, l: PNode, r: PNode): PNode =
   infix(ctx, l, r, mEqRef)
@@ -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

@@ -9,6 +9,7 @@ define:nimPreviewSlimSystem
 define:nimPreviewCstringConversion
 define:nimPreviewProcConversion
 define:nimPreviewRangeDefault
+define:nimPreviewNonVarDestructor
 threads:off
 
 #import:"$projectpath/testability"
@@ -41,5 +42,22 @@ define:useStdoutAsStdmsg
 @end
 
 @if nimHasWarnBareExcept:
+  warning[BareExcept]:on
   warningAserror[BareExcept]:on
 @end
+
+
+@if nimUseStrictDefs:
+  experimental:strictDefs
+  warningAsError[Uninit]:on
+  warningAsError[ProveInit]:on
+@end
+
+@if nimHasWarnStdPrefix:
+  warning[StdPrefix]:on
+  warningAsError[StdPrefix]:on
+@end
+
+@if nimHasVtables:
+  experimental:vtables
+@end

compiler/nim.nim

@@ -28,7 +28,7 @@ import
   commands, options, msgs, extccomp, main, idents, lineinfos, cmdlinehelper,
   pathutils, modulegraphs
 
-from browsers import openDefaultBrowser
+from std/browsers import openDefaultBrowser
 from nodejs import findNodeJs
 
 when hasTinyCBackend:
@@ -91,6 +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(
@@ -113,7 +116,8 @@ proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
     conf.backend = backendC
 
   if conf.selectedGC == gcUnselected:
-    if conf.backend in {backendC, backendCpp, backendObjc}:
+    if conf.backend in {backendC, backendCpp, backendObjc, backendNir} or
+        (conf.cmd == cmdInteractive and isDefined(conf, "nir")):
       initOrcDefines(conf)
 
   mainCommand(graph)
@@ -137,7 +141,7 @@ proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
         # tasyncjs_fail` would fail, refs https://nodejs.org/api/cli.html#cli_unhandled_rejections_mode
         if cmdPrefix.len == 0: cmdPrefix = findNodeJs().quoteShell
         cmdPrefix.add " --unhandled-rejections=strict"
-      else: doAssert false, $conf.backend
+      else: raiseAssert $conf.backend
       if cmdPrefix.len > 0: cmdPrefix.add " "
         # without the `cmdPrefix.len > 0` check, on windows you'd get a cryptic:
         # `The parameter is incorrect`

compiler/nimblecmd.nim

@@ -9,8 +9,9 @@
 
 ## Implements some helper procs for Nimble (Nim's package manager) support.
 
-import parseutils, strutils, os, options, msgs, sequtils, lineinfos, pathutils,
-  tables
+import options, msgs, lineinfos, pathutils
+
+import std/[parseutils, strutils, os, tables, sequtils]
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions]
@@ -37,11 +38,16 @@ proc isSpecial(ver: Version): bool =
 
 proc isValidVersion(v: string): bool =
   if v.len > 0:
-    if v[0] in {'#'} + Digits: return true
+    if v[0] in {'#'} + Digits:
+      result = true
+    else:
+      result = false
+  else:
+    result = false
 
 proc `<`*(ver: Version, ver2: Version): bool =
   ## This is synced from Nimble's version module.
-
+  result = false
   # Handling for special versions such as "#head" or "#branch".
   if ver.isSpecial or ver2.isSpecial:
     if ver2.isSpecial and ($ver2).normalize == "#head":
@@ -145,7 +151,7 @@ proc addNimblePath(conf: ConfigRef; p: string, info: TLineInfo) =
     conf.lazyPaths.insert(AbsoluteDir path, 0)
 
 proc addPathRec(conf: ConfigRef; dir: string, info: TLineInfo) =
-  var packages: PackageInfo
+  var packages: PackageInfo = initTable[string, tuple[version, checksum: string]]()
   var pos = dir.len-1
   if dir[pos] in {DirSep, AltSep}: inc(pos)
   for k,p in os.walkDir(dir):

compiler/nimconf.nim

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

compiler/nimlexbase.nim

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

compiler/nimpaths.nim

@@ -17,7 +17,7 @@ interpolation variables:
 Unstable API
 ]##
 
-import os, strutils
+import std/[os, strutils]
 
 when defined(nimPreviewSlimSystem):
   import std/assertions

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 +1,983 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+# We produce C code as a list of tokens.
+
+import std / [assertions, syncio, tables, intsets, formatfloat]
+from std / strutils import toOctal
+import .. / ic / [bitabs, rodfiles]
+import nirtypes, nirinsts, nirfiles
+import ../../dist/checksums/src/checksums/md5
+
+type
+  Token = LitId # indexing into the tokens BiTable[string]
+
+  PredefinedToken = enum
+    IgnoreMe = "<unused>"
+    EmptyToken = ""
+    CurlyLe = "{"
+    CurlyRi = "}"
+    ParLe = "("
+    ParRi = ")"
+    BracketLe = "["
+    BracketRi = "]"
+    NewLine = "\n"
+    Semicolon = ";"
+    Comma = ", "
+    Space = " "
+    Colon = ": "
+    Dot = "."
+    Arrow = "->"
+    Star = "*"
+    Amp = "&"
+    AsgnOpr = " = "
+    ScopeOpr = "::"
+    ConstKeyword = "const "
+    StaticKeyword = "static "
+    ExternKeyword = "extern "
+    WhileKeyword = "while "
+    IfKeyword = "if ("
+    ElseKeyword = "else "
+    SwitchKeyword = "switch "
+    CaseKeyword = "case "
+    DefaultKeyword = "default:"
+    BreakKeyword = "break"
+    NullPtr = "nullptr"
+    IfNot = "if (!("
+    ReturnKeyword = "return "
+    TypedefStruct = "typedef struct "
+    TypedefUnion = "typedef union "
+    IncludeKeyword = "#include "
+
+proc fillTokenTable(tab: var BiTable[string]) =
+  for e in EmptyToken..high(PredefinedToken):
+    let id = tab.getOrIncl $e
+    assert id == LitId(e), $(id, " ", ord(e))
+
+type
+  GeneratedCode* = object
+    m: NirModule
+    includes: seq[LitId]
+    includedHeaders: IntSet
+    data: seq[LitId]
+    protos: seq[LitId]
+    code: seq[LitId]
+    init: seq[LitId]
+    tokens: BiTable[string]
+    emittedStrings: IntSet
+    needsPrefix: IntSet
+    generatedTypes: IntSet
+    mangledModules: Table[LitId, LitId]
+
+proc initGeneratedCode*(m: sink NirModule): GeneratedCode =
+  result = GeneratedCode(m: m, code: @[], tokens: initBiTable[string]())
+  fillTokenTable(result.tokens)
+
+proc add*(g: var GeneratedCode; t: PredefinedToken) {.inline.} =
+  g.code.add Token(t)
+
+proc add*(g: var GeneratedCode; s: string) {.inline.} =
+  g.code.add g.tokens.getOrIncl(s)
+
+proc mangleModuleName(c: var GeneratedCode; key: LitId): LitId =
+  result = c.mangledModules.getOrDefault(key, LitId(0))
+  if result == LitId(0):
+    let u {.cursor.} = c.m.lit.strings[key]
+    var last = u.len - len(".nim") - 1
+    var start = last
+    while start >= 0 and u[start] != '/': dec start
+    var sum = getMD5(u)
+    sum.setLen(8)
+    let dest = u.substr(start+1, last) & sum
+    result = c.tokens.getOrIncl(dest)
+    c.mangledModules[key] = result
+
+type
+  CppFile = object
+    f: File
+
+proc write(f: var CppFile; s: string) = write(f.f, s)
+proc write(f: var CppFile; c: char) = write(f.f, c)
+
+proc writeTokenSeq(f: var CppFile; s: seq[Token]; c: GeneratedCode) =
+  var indent = 0
+  for i in 0..<s.len:
+    let x = s[i]
+    case x
+    of Token(CurlyLe):
+      inc indent
+      write f, c.tokens[x]
+      write f, "\n"
+      for i in 1..indent*2: write f, ' '
+    of Token(CurlyRi):
+      dec indent
+      write f, c.tokens[x]
+      if i+1 < s.len and s[i+1] == Token(CurlyRi):
+        discard
+      else:
+        write f, "\n"
+        for i in 1..indent*2: write f, ' '
+    of Token(Semicolon):
+      write f, c.tokens[x]
+      if i+1 < s.len and s[i+1] == Token(CurlyRi):
+        discard "no newline before }"
+      else:
+        write f, "\n"
+        for i in 1..indent*2: write f, ' '
+    of Token(NewLine):
+      write f, c.tokens[x]
+      for i in 1..indent*2: write f, ' '
+    else:
+      write f, c.tokens[x]
+
+
+# Type graph
+
+type
+  TypeList = object
+    processed: IntSet
+    s: seq[(TypeId, PredefinedToken)]
+
+proc add(dest: var TypeList; elem: TypeId; decl: PredefinedToken) =
+  if not containsOrIncl(dest.processed, int(elem)):
+    dest.s.add (elem, decl)
+
+type
+  TypeOrder = object
+    forwardedDecls, ordered: TypeList
+    typeImpls: Table[string, TypeId]
+    lookedAt: IntSet
+
+proc traverseObject(types: TypeGraph; lit: Literals; c: var TypeOrder; t: TypeId)
+
+proc recordDependency(types: TypeGraph; lit: Literals; c: var TypeOrder; parent, child: TypeId) =
+  var ch = child
+  var viaPointer = false
+  while true:
+    case types[ch].kind
+    of APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy:
+      viaPointer = true
+      ch = elementType(types, ch)
+    of LastArrayTy:
+      ch = elementType(types, ch)
+    else:
+      break
+
+  case types[ch].kind
+  of ObjectTy, UnionTy:
+    let decl = if types[ch].kind == ObjectTy: TypedefStruct else: TypedefUnion
+    let obj = c.typeImpls.getOrDefault(lit.strings[types[ch].litId])
+    if viaPointer:
+      c.forwardedDecls.add obj, decl
+    else:
+      if not containsOrIncl(c.lookedAt, obj.int):
+        traverseObject(types, lit, c, obj)
+      c.ordered.add obj, decl
+  of ArrayTy:
+    if viaPointer:
+      c.forwardedDecls.add ch, TypedefStruct
+    else:
+      if not containsOrIncl(c.lookedAt, ch.int):
+        traverseObject(types, lit, c, ch)
+      c.ordered.add ch, TypedefStruct
+  else:
+    discard "uninteresting type as we only focus on the required struct declarations"
+
+proc traverseObject(types: TypeGraph; lit: Literals; c: var TypeOrder; t: TypeId) =
+  for x in sons(types, t):
+    case types[x].kind
+    of FieldDecl:
+      recordDependency types, lit, c, t, x.firstSon
+    of ObjectTy:
+      # inheritance
+      recordDependency types, lit, c, t, x
+    else: discard
+
+proc traverseTypes(types: TypeGraph; lit: Literals; c: var TypeOrder) =
+  for t in allTypes(types):
+    if types[t].kind in {ObjectDecl, UnionDecl}:
+      assert types[t.firstSon].kind == NameVal
+      c.typeImpls[lit.strings[types[t.firstSon].litId]] = t
+
+  for t in allTypesIncludingInner(types):
+    case types[t].kind
+    of ObjectDecl, UnionDecl:
+      traverseObject types, lit, c, t
+      let decl = if types[t].kind == ObjectDecl: TypedefStruct else: TypedefUnion
+      c.ordered.add t, decl
+    of ArrayTy:
+      traverseObject types, lit, c, t
+      c.ordered.add t, TypedefStruct
+    else: discard
+
+when false:
+  template emitType(s: string) = c.types.add c.tokens.getOrIncl(s)
+  template emitType(t: Token) = c.types.add t
+  template emitType(t: PredefinedToken) = c.types.add Token(t)
+
+proc genType(g: var GeneratedCode; types: TypeGraph; lit: Literals; t: TypeId; name = "") =
+  template maybeAddName =
+    if name != "":
+      g.add Space
+      g.add name
+
+  template atom(s: string) =
+    g.add s
+    maybeAddName()
+  case types[t].kind
+  of VoidTy: atom "void"
+  of IntTy: atom "NI" & $types[t].integralBits
+  of UIntTy: atom "NU" & $types[t].integralBits
+  of FloatTy: atom "NF" & $types[t].integralBits
+  of BoolTy: atom "NB" & $types[t].integralBits
+  of CharTy: atom "NC" & $types[t].integralBits
+  of ObjectTy, UnionTy, NameVal, AnnotationVal:
+    atom lit.strings[types[t].litId]
+  of VarargsTy:
+    g.add "..."
+  of APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy:
+    genType g, types, lit, elementType(types, t)
+    g.add Star
+    maybeAddName()
+  of ArrayTy:
+    genType g, types, lit, arrayName(types, t)
+    maybeAddName()
+  of LastArrayTy:
+    genType g, types, lit, elementType(types, t)
+    maybeAddName()
+    g.add BracketLe
+    g.add BracketRi
+  of ProcTy:
+    let (retType, callConv) = returnType(types, t)
+    genType g, types, lit, retType
+    g.add Space
+    g.add ParLe
+    genType g, types, lit, callConv
+    g.add Star # "(*fn)"
+    maybeAddName()
+    g.add ParRi
+    g.add ParLe
+    var i = 0
+    for ch in params(types, t):
+      if i > 0: g.add Comma
+      genType g, types, lit, ch
+      inc i
+    g.add ParRi
+  of ObjectDecl, UnionDecl:
+    atom lit.strings[types[t.firstSon].litId]
+  of IntVal, SizeVal, AlignVal, OffsetVal, FieldDecl:
+    #raiseAssert "did not expect: " & $types[t].kind
+    g.add "BUG "
+    atom $types[t].kind
+
+proc generateTypes(g: var GeneratedCode; types: TypeGraph; lit: Literals; c: TypeOrder) =
+  for (t, declKeyword) in c.forwardedDecls.s:
+    let name = if types[t].kind == ArrayTy: arrayName(types, t) else: t.firstSon
+    let s {.cursor.} = lit.strings[types[name].litId]
+    g.add declKeyword
+    g.add s
+    g.add Space
+    g.add s
+    g.add Semicolon
+
+  for (t, declKeyword) in c.ordered.s:
+    let name = if types[t].kind == ArrayTy: arrayName(types, t) else: t.firstSon
+    let litId = types[name].litId
+    if not g.generatedTypes.containsOrIncl(litId.int):
+      let s {.cursor.} = lit.strings[litId]
+      g.add declKeyword
+      g.add CurlyLe
+      if types[t].kind == ArrayTy:
+        genType g, types, lit, elementType(types, t), "a"
+        g.add BracketLe
+        g.add $arrayLen(types, t)
+        g.add BracketRi
+        g.add Semicolon
+      else:
+        var i = 0
+        for x in sons(types, t):
+          case types[x].kind
+          of FieldDecl:
+            genType g, types, lit, x.firstSon, "F" & $i
+            g.add Semicolon
+            inc i
+          of ObjectTy:
+            genType g, types, lit, x, "P"
+            g.add Semicolon
+          else: discard
+      g.add CurlyRi
+      g.add s
+      g.add Semicolon
+
+# Procs
+
+proc toCChar*(c: char; result: var string) {.inline.} =
+  case c
+  of '\0'..'\x1F', '\x7F'..'\xFF':
+    result.add '\\'
+    result.add toOctal(c)
+  of '\'', '\"', '\\', '?':
+    result.add '\\'
+    result.add c
+  else:
+    result.add c
+
+proc makeCString(s: string): string =
+  result = newStringOfCap(s.len + 10)
+  result.add('"')
+  for c in s: toCChar(c, result)
+  result.add('"')
+
+template emitData(s: string) = c.data.add c.tokens.getOrIncl(s)
+template emitData(t: Token) = c.data.add t
+template emitData(t: PredefinedToken) = c.data.add Token(t)
+
+proc genStrLit(c: var GeneratedCode; lit: Literals; litId: LitId): Token =
+  result = Token(c.tokens.getOrIncl "QStr" & $litId)
+  if not containsOrIncl(c.emittedStrings, int(litId)):
+    let s {.cursor.} = lit.strings[litId]
+    emitData "static const struct "
+    emitData CurlyLe
+    emitData "NI cap"
+    emitData Semicolon
+    emitData "NC8 data"
+    emitData BracketLe
+    emitData $s.len
+    emitData "+1"
+    emitData BracketRi
+    emitData Semicolon
+    emitData CurlyRi
+    emitData result
+    emitData AsgnOpr
+    emitData CurlyLe
+    emitData $s.len
+    emitData " | NIM_STRLIT_FLAG"
+    emitData Comma
+    emitData makeCString(s)
+    emitData CurlyRi
+    emitData Semicolon
+
+proc genIntLit(c: var GeneratedCode; lit: Literals; litId: LitId) =
+  let i = lit.numbers[litId]
+  if i > low(int32) and i <= high(int32):
+    c.add $i
+  elif i == low(int32):
+    # Nim has the same bug for the same reasons :-)
+    c.add "(-2147483647 -1)"
+  elif i > low(int64):
+    c.add "IL64("
+    c.add $i
+    c.add ")"
+  else:
+    c.add "(IL64(-9223372036854775807) - IL64(1))"
+
+proc gen(c: var GeneratedCode; t: Tree; n: NodePos)
+
+proc genDisplayName(c: var GeneratedCode; symId: SymId) =
+  let displayName = c.m.symnames[symId]
+  if displayName != LitId(0):
+    c.add "/*"
+    c.add c.m.lit.strings[displayName]
+    c.add "*/"
+
+proc genSymDef(c: var GeneratedCode; t: Tree; n: NodePos) =
+  if t[n].kind == SymDef:
+    let symId = t[n].symId
+    c.needsPrefix.incl symId.int
+    genDisplayName c, symId
+  gen c, t, n
+
+proc genGlobal(c: var GeneratedCode; t: Tree; name, typ: NodePos; annotation: string) =
+  c.add annotation
+  let m: string
+  if t[name].kind == SymDef:
+    let symId = t[name].symId
+    m = c.tokens[mangleModuleName(c, c.m.namespace)] & "__" & $symId
+    genDisplayName c, symId
+  else:
+    assert t[name].kind == ModuleSymUse
+    let (x, y) = sons2(t, name)
+    m = c.tokens[mangleModuleName(c, t[x].litId)] & "__" & $t[y].immediateVal
+  genType c, c.m.types, c.m.lit, t[typ].typeId, m
+
+proc genLocal(c: var GeneratedCode; t: Tree; name, typ: NodePos; annotation: string) =
+  assert t[name].kind == SymDef
+  c.add annotation
+  let symId = t[name].symId
+  genType c, c.m.types, c.m.lit, t[typ].typeId, "q" & $symId
+  genDisplayName c, symId
+
+proc genProcDecl(c: var GeneratedCode; t: Tree; n: NodePos; isExtern: bool) =
+  let signatureBegin = c.code.len
+  let name = n.firstSon
+
+  var prc = n.firstSon
+  next t, prc
+
+  while true:
+    case t[prc].kind
+    of PragmaPair:
+      let (x, y) = sons2(t, prc)
+      let key = cast[PragmaKey](t[x].rawOperand)
+      case key
+      of HeaderImport:
+        let lit = t[y].litId
+        let headerAsStr {.cursor.} = c.m.lit.strings[lit]
+        let header = c.tokens.getOrIncl(headerAsStr)
+        # headerAsStr can be empty, this has the semantics of the `nodecl` pragma:
+        if headerAsStr.len > 0 and not c.includedHeaders.containsOrIncl(int header):
+          if headerAsStr[0] == '#':
+            discard "skip the #include"
+          else:
+            c.includes.add Token(IncludeKeyword)
+          c.includes.add header
+          c.includes.add Token NewLine
+        # do not generate code for importc'ed procs:
+        return
+      of DllImport:
+        let lit = t[y].litId
+        raiseAssert "cannot eval: " & c.m.lit.strings[lit]
+      else: discard
+    of PragmaId: discard
+    else: break
+    next t, prc
+
+  var resultDeclPos = NodePos(-1)
+  if t[prc].kind == SummonResult:
+    resultDeclPos = prc
+    gen c, t, prc.firstSon
+    next t, prc
+  else:
+    c.add "void"
+  c.add Space
+  genSymDef c, t, name
+  c.add ParLe
+  var params = 0
+  while t[prc].kind == SummonParam:
+    if params > 0: c.add Comma
+    let (typ, sym) = sons2(t, prc)
+    genLocal c, t, sym, typ, ""
+    next t, prc
+    inc params
+  if params == 0:
+    c.add "void"
+  c.add ParRi
+
+  for i in signatureBegin ..< c.code.len:
+    c.protos.add c.code[i]
+  c.protos.add Token Semicolon
+
+  if isExtern:
+    c.code.setLen signatureBegin
+  else:
+    c.add CurlyLe
+    if resultDeclPos.int >= 0:
+      gen c, t, resultDeclPos
+    for ch in sonsRest(t, n, prc):
+      gen c, t, ch
+    c.add CurlyRi
+
+template triop(opr) =
+  let (typ, a, b) = sons3(t, n)
+  c.add ParLe
+  c.add ParLe
+  gen c, t, typ
+  c.add ParRi
+  gen c, t, a
+  c.add opr
+  gen c, t, b
+  c.add ParRi
+
+template cmpop(opr) =
+  let (_, a, b) = sons3(t, n)
+  c.add ParLe
+  gen c, t, a
+  c.add opr
+  gen c, t, b
+  c.add ParRi
+
+template binaryop(opr) =
+  let (typ, a) = sons2(t, n)
+  c.add ParLe
+  c.add ParLe
+  gen c, t, typ
+  c.add ParRi
+  c.add opr
+  gen c, t, a
+  c.add ParRi
+
+template checkedBinaryop(opr) =
+  let (typ, labIdx, a, b) = sons4(t, n)
+  let bits = integralBits(c.m.types[t[typ].typeId])
+  let lab = t[labIdx].label
+
+  c.add (opr & $bits)
+  c.add ParLe
+  c.gen t, a
+  c.add Comma
+  c.gen t, b
+  c.add Comma
+  c.add "L" & $lab.int
+  c.add ParRi
+
+proc genNumberConv(c: var GeneratedCode; t: Tree; n: NodePos) =
+  let (typ, arg) = sons2(t, n)
+  if t[arg].kind == IntVal:
+    let litId = t[arg].litId
+    c.add ParLe
+    c.add ParLe
+    gen c, t, typ
+    c.add ParRi
+    case c.m.types[t[typ].typeId].kind
+    of UIntTy:
+      let x = cast[uint64](c.m.lit.numbers[litId])
+      c.add $x
+    of FloatTy:
+      let x = cast[float64](c.m.lit.numbers[litId])
+      c.add $x
+    else:
+      gen c, t, arg
+    c.add ParRi
+  else:
+    binaryop ""
+
+template moveToDataSection(body: untyped) =
+  let oldLen = c.code.len
+  body
+  for i in oldLen ..< c.code.len:
+    c.data.add c.code[i]
+  setLen c.code, oldLen
+
+proc gen(c: var GeneratedCode; t: Tree; n: NodePos) =
+  case t[n].kind
+  of Nop:
+    discard "nothing to emit"
+  of ImmediateVal:
+    c.add $t[n].immediateVal
+  of IntVal:
+    genIntLit c, c.m.lit, t[n].litId
+  of StrVal:
+    c.code.add genStrLit(c, c.m.lit, t[n].litId)
+  of Typed:
+    genType c, c.m.types, c.m.lit, t[n].typeId
+  of SymDef, SymUse:
+    let s = t[n].symId
+    if c.needsPrefix.contains(s.int):
+      c.code.add mangleModuleName(c, c.m.namespace)
+      c.add "__"
+      c.add $s
+    else:
+      # XXX Use proper names here
+      c.add "q"
+      c.add $s
+
+  of ModuleSymUse:
+    let (x, y) = sons2(t, n)
+    let u = mangleModuleName(c, t[x].litId)
+    let s = t[y].immediateVal
+    c.code.add u
+    c.add "__"
+    c.add $s
+
+  of NilVal:
+    c.add NullPtr
+  of LoopLabel:
+    c.add WhileKeyword
+    c.add ParLe
+    c.add "1"
+    c.add ParRi
+    c.add CurlyLe
+  of GotoLoop:
+    c.add CurlyRi
+  of Label:
+    let lab = t[n].label
+    c.add "L"
+    c.add $lab.int
+    c.add Colon
+    c.add Semicolon
+  of Goto:
+    let lab = t[n].label
+    c.add "goto L"
+    c.add $lab.int
+    c.add Semicolon
+  of CheckedGoto:
+    discard "XXX todo"
+  of ArrayConstr:
+    c.add CurlyLe
+    c.add ".a = "
+    c.add CurlyLe
+    var i = 0
+    for ch in sonsFrom1(t, n):
+      if i > 0: c.add Comma
+      c.gen t, ch
+      inc i
+    c.add CurlyRi
+    c.add CurlyRi
+  of ObjConstr:
+    c.add CurlyLe
+    var i = 0
+    for ch in sonsFrom1(t, n):
+      if i mod 2 == 0:
+        if i > 0: c.add Comma
+        c.add ".F" & $t[ch].immediateVal
+        c.add AsgnOpr
+      else:
+        c.gen t, ch
+      inc i
+    c.add CurlyRi
+  of Ret:
+    c.add ReturnKeyword
+    c.gen t, n.firstSon
+    c.add Semicolon
+  of Select:
+    c.add SwitchKeyword
+    c.add ParLe
+    let (_, selector) = sons2(t, n)
+    c.gen t, selector
+    c.add ParRi
+    c.add CurlyLe
+    for ch in sonsFromN(t, n, 2):
+      c.gen t, ch
+    c.add CurlyRi
+  of SelectPair:
+    let (le, ri) = sons2(t, n)
+    c.gen t, le
+    c.gen t, ri
+  of SelectList:
+    for ch in sons(t, n):
+      c.gen t, ch
+  of SelectValue:
+    c.add CaseKeyword
+    c.gen t, n.firstSon
+    c.add Colon
+  of SelectRange:
+    let (le, ri) = sons2(t, n)
+    c.add CaseKeyword
+    c.gen t, le
+    c.add " ... "
+    c.gen t, ri
+    c.add Colon
+  of ForeignDecl:
+    c.data.add LitId(ExternKeyword)
+    c.gen t, n.firstSon
+  of SummonGlobal:
+    moveToDataSection:
+      let (typ, sym) = sons2(t, n)
+      c.genGlobal t, sym, typ, ""
+      c.add Semicolon
+  of SummonThreadLocal:
+    moveToDataSection:
+      let (typ, sym) = sons2(t, n)
+      c.genGlobal t, sym, typ, "__thread "
+      c.add Semicolon
+  of SummonConst:
+    moveToDataSection:
+      let (typ, sym, val) = sons3(t, n)
+      c.genGlobal t, sym, typ, "const "
+      c.add AsgnOpr
+      c.gen t, val
+      c.add Semicolon
+  of Summon, SummonResult:
+    let (typ, sym) = sons2(t, n)
+    c.genLocal t, sym, typ, ""
+    c.add Semicolon
+
+  of SummonParam:
+    raiseAssert "SummonParam should have been handled in genProc"
+  of Kill:
+    discard "we don't care about Kill instructions"
+  of AddrOf:
+    let (_, arg) = sons2(t, n)
+    c.add "&"
+    gen c, t, arg
+  of DerefArrayAt:
+    let (_, a, i) = sons3(t, n)
+    gen c, t, a
+    c.add BracketLe
+    gen c, t, i
+    c.add BracketRi
+  of ArrayAt:
+    let (_, a, i) = sons3(t, n)
+    gen c, t, a
+    c.add Dot
+    c.add "a"
+    c.add BracketLe
+    gen c, t, i
+    c.add BracketRi
+  of FieldAt:
+    let (_, a, b) = sons3(t, n)
+    gen c, t, a
+    let field = t[b].immediateVal
+    c.add Dot
+    c.add "F" & $field
+  of DerefFieldAt:
+    let (_, a, b) = sons3(t, n)
+    gen c, t, a
+    let field = t[b].immediateVal
+    c.add Arrow
+    c.add "F" & $field
+  of Load:
+    let (_, arg) = sons2(t, n)
+    c.add ParLe
+    c.add "*"
+    gen c, t, arg
+    c.add ParRi
+  of Store:
+    raiseAssert "Assumption was that Store is unused!"
+  of Asgn:
+    let (_, dest, src) = sons3(t, n)
+    gen c, t, dest
+    c.add AsgnOpr
+    gen c, t, src
+    c.add Semicolon
+  of CheckedRange:
+    c.add "nimCheckRange"
+    c.add ParLe
+    let (_, gotoInstr, x, a, b) = sons5(t, n)
+    gen c, t, x
+    c.add Comma
+    gen c, t, a
+    c.add Comma
+    gen c, t, b
+    c.add Comma
+    c.add "L" & $t[gotoInstr].label.int
+    c.add ParRi
+  of CheckedIndex:
+    c.add "nimCheckIndex"
+    c.add ParLe
+    let (gotoInstr, x, a) = sons3(t, n)
+    gen c, t, x
+    c.add Comma
+    gen c, t, a
+    c.add Comma
+    c.add "L" & $t[gotoInstr].label.int
+    c.add ParRi
+  of Call, IndirectCall:
+    let (typ, fn) = sons2(t, n)
+    gen c, t, fn
+    c.add ParLe
+    var i = 0
+    for ch in sonsFromN(t, n, 2):
+      if i > 0: c.add Comma
+      gen c, t, ch
+      inc i
+    c.add ParRi
+    if c.m.types[t[typ].typeId].kind == VoidTy:
+      c.add Semicolon
+  of CheckedCall, CheckedIndirectCall:
+    let (typ, gotoInstr, fn) = sons3(t, n)
+    gen c, t, fn
+    c.add ParLe
+    var i = 0
+    for ch in sonsFromN(t, n, 3):
+      if i > 0: c.add Comma
+      gen c, t, ch
+      inc i
+    c.add ParRi
+    if c.m.types[t[typ].typeId].kind == VoidTy:
+      c.add Semicolon
+
+  of CheckedAdd: checkedBinaryop "nimAddInt"
+  of CheckedSub: checkedBinaryop "nimSubInt"
+  of CheckedMul: checkedBinaryop "nimMulInt"
+  of CheckedDiv: checkedBinaryop "nimDivInt"
+  of CheckedMod: checkedBinaryop "nimModInt"
+  of Add: triop " + "
+  of Sub: triop " - "
+  of Mul: triop " * "
+  of Div: triop " / "
+  of Mod: triop " % "
+  of BitShl: triop " << "
+  of BitShr: triop " >> "
+  of BitAnd: triop " & "
+  of BitOr: triop " | "
+  of BitXor: triop " ^ "
+  of BitNot: binaryop " ~ "
+  of BoolNot: binaryop " !"
+  of Eq: cmpop " == "
+  of Le: cmpop " <= "
+  of Lt: cmpop " < "
+  of Cast: binaryop ""
+  of NumberConv: genNumberConv c, t, n
+  of CheckedObjConv: binaryop ""
+  of ObjConv: binaryop ""
+  of Emit: raiseAssert "cannot interpret: Emit"
+  of ProcDecl: genProcDecl c, t, n, false
+  of ForeignProcDecl: genProcDecl c, t, n, true
+  of PragmaPair, PragmaId, TestOf, Yld, SetExc, TestExc:
+    c.add "cannot interpret: " & $t[n].kind
+
+const
+  Prelude = """
+/* GENERATED CODE. DO NOT EDIT. */
+
+#ifdef __cplusplus
+#define NB8 bool
+#elif (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901)
+// see #13798: to avoid conflicts for code emitting `#include <stdbool.h>`
+#define NB8 _Bool
+#else
+typedef unsigned char NB8; // best effort
+#endif
+
+typedef unsigned char NC8;
+
+typedef float NF32;
+typedef double NF64;
+#if defined(__BORLANDC__) || defined(_MSC_VER)
+typedef signed char NI8;
+typedef signed short int NI16;
+typedef signed int NI32;
+typedef __int64 NI64;
+/* XXX: Float128? */
+typedef unsigned char NU8;
+typedef unsigned short int NU16;
+typedef unsigned int NU32;
+typedef unsigned __int64 NU64;
+#elif defined(HAVE_STDINT_H)
+#ifndef USE_NIM_NAMESPACE
+#  include <stdint.h>
+#endif
+typedef int8_t NI8;
+typedef int16_t NI16;
+typedef int32_t NI32;
+typedef int64_t NI64;
+typedef uint8_t NU8;
+typedef uint16_t NU16;
+typedef uint32_t NU32;
+typedef uint64_t NU64;
+#elif defined(HAVE_CSTDINT)
+#ifndef USE_NIM_NAMESPACE
+#  include <cstdint>
+#endif
+typedef std::int8_t NI8;
+typedef std::int16_t NI16;
+typedef std::int32_t NI32;
+typedef std::int64_t NI64;
+typedef std::uint8_t NU8;
+typedef std::uint16_t NU16;
+typedef std::uint32_t NU32;
+typedef std::uint64_t NU64;
+#else
+/* Unknown compiler/version, do our best */
+#ifdef __INT8_TYPE__
+typedef __INT8_TYPE__ NI8;
+#else
+typedef signed char NI8;
+#endif
+#ifdef __INT16_TYPE__
+typedef __INT16_TYPE__ NI16;
+#else
+typedef signed short int NI16;
+#endif
+#ifdef __INT32_TYPE__
+typedef __INT32_TYPE__ NI32;
+#else
+typedef signed int NI32;
+#endif
+#ifdef __INT64_TYPE__
+typedef __INT64_TYPE__ NI64;
+#else
+typedef long long int NI64;
+#endif
+/* XXX: Float128? */
+#ifdef __UINT8_TYPE__
+typedef __UINT8_TYPE__ NU8;
+#else
+typedef unsigned char NU8;
+#endif
+#ifdef __UINT16_TYPE__
+typedef __UINT16_TYPE__ NU16;
+#else
+typedef unsigned short int NU16;
+#endif
+#ifdef __UINT32_TYPE__
+typedef __UINT32_TYPE__ NU32;
+#else
+typedef unsigned int NU32;
+#endif
+#ifdef __UINT64_TYPE__
+typedef __UINT64_TYPE__ NU64;
+#else
+typedef unsigned long long int NU64;
+#endif
+#endif
+
+#ifdef NIM_INTBITS
+#  if NIM_INTBITS == 64
+typedef NI64 NI;
+typedef NU64 NU;
+#  elif NIM_INTBITS == 32
+typedef NI32 NI;
+typedef NU32 NU;
+#  elif NIM_INTBITS == 16
+typedef NI16 NI;
+typedef NU16 NU;
+#  elif NIM_INTBITS == 8
+typedef NI8 NI;
+typedef NU8 NU;
+#  else
+#    error "invalid bit width for int"
+#  endif
+#endif
+
+#define NIM_STRLIT_FLAG ((NU)(1) << ((NIM_INTBITS) - 2)) /* This has to be the same as system.strlitFlag! */
+
+#define nimAddInt64(a, b, L) ({long long int res; if(__builtin_saddll_overflow(a, b, &res)) goto L; res})
+#define nimSubInt64(a, b, L) ({long long int res; if(__builtin_ssubll_overflow(a, b, &res)) goto L; res})
+#define nimMulInt64(a, b, L) ({long long int res; if(__builtin_smulll_overflow(a, b, &res)) goto L; res})
+
+#define nimAddInt32(a, b, L) ({long int res; if(__builtin_sadd_overflow(a, b, &res)) goto L; res})
+#define nimSubInt32(a, b, L) ({long int res; if(__builtin_ssub_overflow(a, b, &res)) goto L; res})
+#define nimMulInt32(a, b, L) ({long int res; if(__builtin_smul_overflow(a, b, &res)) goto L; res})
+
+#define nimCheckRange(x, a, b, L) ({if (x < a || x > b) goto L; x})
+#define nimCheckIndex(x, a, L) ({if (x >= a) goto L; x})
+
+"""
+
+proc traverseCode(c: var GeneratedCode) =
+  const AllowedInToplevelC = {SummonConst, SummonGlobal, SummonThreadLocal,
+                              ProcDecl, ForeignDecl, ForeignProcDecl}
+  var i = NodePos(0)
+  while i.int < c.m.code.len:
+    let oldLen = c.code.len
+    let moveToInitSection = c.m.code[NodePos(i)].kind notin AllowedInToplevelC
+
+    gen c, c.m.code, NodePos(i)
+    next c.m.code, i
+
+    if moveToInitSection:
+      for i in oldLen ..< c.code.len:
+        c.init.add c.code[i]
+      setLen c.code, oldLen
+
+proc generateCode*(inp, outp: string) =
+  var c = initGeneratedCode(load(inp))
+
+  var co = TypeOrder()
+  traverseTypes(c.m.types, c.m.lit, co)
+
+  generateTypes(c, c.m.types, c.m.lit, co)
+  let typeDecls = move c.code
+
+  traverseCode c
+  var f = CppFile(f: open(outp, fmWrite))
+  f.write "#define NIM_INTBITS " & $c.m.intbits & "\n"
+  f.write Prelude
+  writeTokenSeq f, c.includes, c
+  writeTokenSeq f, typeDecls, c
+  writeTokenSeq f, c.data, c
+  writeTokenSeq f, c.protos, c
+  writeTokenSeq f, c.code, c
+  if c.init.len > 0:
+    f.write "void __attribute__((constructor)) init(void) {"
+    writeTokenSeq f, c.init, c
+    f.write "}\n\n"
+  f.f.close

compiler/nir/nir.nim

@@ -0,0 +1,105 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Nim Intermediate Representation, designed to capture all of Nim's semantics without losing too much
+## precious information. Can easily be translated into C. And to JavaScript, hopefully.
+
+from std/os import addFileExt, `/`, createDir
+
+import std / assertions
+import ".." / [ast, modulegraphs, renderer, transf, options, msgs, lineinfos]
+import nirtypes, nirinsts, ast2ir, nirlineinfos, nirfiles, nirvm
+
+import ".." / ic / [rodfiles, bitabs]
+
+type
+  PCtx* = ref object of TPassContext
+    m: ModuleCon
+    c: ProcCon
+    oldErrorCount: int
+    bytecode: Bytecode
+
+proc newCtx*(module: PSym; g: ModuleGraph; idgen: IdGenerator): PCtx =
+  var lit = Literals()
+  var nirm = (ref NirModule)(types: initTypeGraph(lit), lit: lit)
+  var m = initModuleCon(g, g.config, idgen, module, nirm)
+  m.noModularity = true
+  PCtx(m: m, c: initProcCon(m, nil, g.config), idgen: idgen, bytecode: initBytecode(nirm))
+
+proc refresh*(c: PCtx; module: PSym; idgen: IdGenerator) =
+  #c.m = initModuleCon(c.m.graph, c.m.graph.config, idgen, module, c.m.nirm)
+  #c.m.noModularity = true
+  c.c = initProcCon(c.m, nil, c.m.graph.config)
+  c.idgen = idgen
+
+proc setupGlobalCtx*(module: PSym; graph: ModuleGraph; idgen: IdGenerator) =
+  if graph.repl.isNil:
+    graph.repl = newCtx(module, graph, idgen)
+    #registerAdditionalOps(PCtx graph.repl)
+  else:
+    refresh(PCtx graph.repl, module, idgen)
+
+proc setupNirReplGen*(graph: ModuleGraph; module: PSym; idgen: IdGenerator): PPassContext =
+  setupGlobalCtx(module, graph, idgen)
+  result = PCtx graph.repl
+
+proc evalStmt(c: PCtx; n: PNode) =
+  let n = transformExpr(c.m.graph, c.idgen, c.m.module, n)
+  let pc = genStmt(c.c, n)
+  #var res = ""
+  #toString c.m.nirm.code, NodePos(pc), c.m.nirm.lit.strings, c.m.nirm.lit.numbers, c.m.symnames, res
+  #res.add "\n--------------------------\n"
+  #toString res, c.m.types.g
+  if pc.int < c.m.nirm.code.len:
+    c.bytecode.interactive = c.m.graph.interactive
+    execCode c.bytecode, c.m.nirm.code, pc
+  #echo res
+
+proc runCode*(c: PPassContext; n: PNode): PNode =
+  let c = PCtx(c)
+  # don't eval errornous code:
+  if c.oldErrorCount == c.m.graph.config.errorCounter:
+    evalStmt(c, n)
+    result = newNodeI(nkEmpty, n.info)
+  else:
+    result = n
+  c.oldErrorCount = c.m.graph.config.errorCounter
+
+type
+  NirPassContext* = ref object of TPassContext
+    m: ModuleCon
+    c: ProcCon
+
+proc openNirBackend*(g: ModuleGraph; module: PSym; idgen: IdGenerator): PPassContext =
+  var lit = Literals()
+  var nirm = (ref NirModule)(types: initTypeGraph(lit), lit: lit)
+  let m = initModuleCon(g, g.config, idgen, module, nirm)
+  NirPassContext(m: m, c: initProcCon(m, nil, g.config), idgen: idgen)
+
+proc gen(c: NirPassContext; n: PNode) =
+  let n = transformExpr(c.m.graph, c.idgen, c.m.module, n)
+  let pc = genStmt(c.c, n)
+
+proc nirBackend*(c: PPassContext; n: PNode): PNode =
+  gen(NirPassContext(c), n)
+  result = n
+
+proc closeNirBackend*(c: PPassContext; finalNode: PNode) =
+  discard nirBackend(c, finalNode)
+
+  let c = NirPassContext(c)
+  let nimcache = getNimcacheDir(c.c.config).string
+  createDir nimcache
+  let outp = nimcache / c.m.module.name.s.addFileExt("nir")
+  #c.m.nirm.code = move c.c.code
+  try:
+    store c.m.nirm[], outp
+    echo "created: ", outp
+  except IOError:
+    rawMessage(c.c.config, errFatal, "serialization failed: " & outp)

compiler/nir/nirc.nim

@@ -0,0 +1,52 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Nir Compiler.
+
+import ".." / ic / [bitabs, rodfiles]
+import nirinsts, nirtypes, nirlineinfos, nirfiles, cir
+
+proc view(filename: string) =
+  let m = load(filename)
+  var res = ""
+  allTreesToString m.code, m.lit.strings, m.lit.numbers, m.symnames, res
+  res.add "\n# TYPES\n"
+  nirtypes.toString res, m.types
+  echo res
+
+import std / [syncio, parseopt]
+
+proc writeHelp =
+  echo """Usage: nirc view|c <file.nir>"""
+  quit 0
+
+proc main =
+  var inp = ""
+  var cmd = ""
+  for kind, key, val in getopt():
+    case kind
+    of cmdArgument:
+      if cmd.len == 0: cmd = key
+      elif inp.len == 0: inp = key
+      else: quit "Error: too many arguments"
+    of cmdLongOption, cmdShortOption:
+      case key
+      of "help", "h": writeHelp()
+      of "version", "v": stdout.write "1.0\n"
+    of cmdEnd: discard
+  if inp.len == 0:
+    quit "Error: no input file specified"
+  case cmd
+  of "", "view":
+    view inp
+  of "c":
+    let outp = inp & ".c"
+    cir.generateCode inp, outp
+
+main()

compiler/nir/nirfiles.nim

@@ -0,0 +1,83 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+import ".." / ic / [bitabs, rodfiles]
+import nirinsts, nirtypes, nirlineinfos
+
+type
+  NirModule* = object
+    code*: Tree
+    man*: LineInfoManager
+    types*: TypeGraph
+    lit*: Literals
+    namespace*: LitId
+    intbits*: uint32
+    symnames*: SymNames
+
+proc load*(filename: string): NirModule =
+  let lit = Literals()
+  result = NirModule(lit: lit, types: initTypeGraph(lit))
+  var r = rodfiles.open(filename)
+  try:
+    r.loadHeader(nirCookie)
+    r.loadSection stringsSection
+    r.load result.lit.strings
+
+    r.loadSection numbersSection
+    r.load result.lit.numbers
+
+    r.loadSection bodiesSection
+    r.load result.code
+
+    r.loadSection typesSection
+    r.load result.types
+
+    r.loadSection sideChannelSection
+    r.load result.man
+
+    r.loadSection namespaceSection
+    r.loadPrim result.namespace
+    r.loadPrim result.intbits
+
+    r.loadSection symnamesSection
+    r.load result.symnames
+
+  finally:
+    r.close()
+
+proc store*(m: NirModule; outp: string) =
+  var r = rodfiles.create(outp)
+  try:
+    r.storeHeader(nirCookie)
+    r.storeSection stringsSection
+    r.store m.lit.strings
+
+    r.storeSection numbersSection
+    r.store m.lit.numbers
+
+    r.storeSection bodiesSection
+    r.store m.code
+
+    r.storeSection typesSection
+    r.store m.types
+
+    r.storeSection sideChannelSection
+    r.store m.man
+
+    r.storeSection namespaceSection
+    r.storePrim m.namespace
+    r.storePrim m.intbits
+
+    r.storeSection symnamesSection
+    r.store m.symnames
+
+  finally:
+    r.close()
+  if r.err != ok:
+    raise newException(IOError, "could store into: " & outp)

compiler/nir/nirinsts.nim

@@ -0,0 +1,582 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## NIR instructions. Somewhat inspired by LLVM's instructions.
+
+import std / [assertions, hashes]
+import .. / ic / [bitabs, rodfiles]
+import nirlineinfos, nirtypes
+
+const
+  NirVersion = 1
+  nirCookie* = [byte(0), byte('N'), byte('I'), byte('R'),
+            byte(sizeof(int)*8), byte(system.cpuEndian), byte(0), byte(NirVersion)]
+
+type
+  SymId* = distinct int
+
+proc `$`*(s: SymId): string {.borrow.}
+proc hash*(s: SymId): Hash {.borrow.}
+proc `==`*(a, b: SymId): bool {.borrow.}
+
+type
+  Opcode* = enum
+    Nop,
+    ImmediateVal,
+    IntVal,
+    StrVal,
+    SymDef,
+    SymUse,
+    Typed,   # with type ID
+    PragmaId, # with Pragma ID, possible values: see PragmaKey enum
+    NilVal,
+    Label,
+    Goto,
+    CheckedGoto,
+    LoopLabel,
+    GotoLoop,  # last atom
+
+    ModuleSymUse, # `"module".x`
+
+    ArrayConstr,
+    ObjConstr,
+    Ret,
+    Yld,
+
+    Select,
+    SelectPair,  # ((values...), Label)
+    SelectList,  # (values...)
+    SelectValue, # (value)
+    SelectRange, # (valueA..valueB)
+    ForeignDecl, # Can wrap SummonGlobal, SummonThreadLocal, SummonConst
+    SummonGlobal,
+    SummonThreadLocal,
+    Summon, # x = Summon Typed <Type ID>; x begins to live
+    SummonResult,
+    SummonParam,
+    SummonConst,
+    Kill, # `Kill x`: scope end for `x`
+
+    AddrOf,
+    ArrayAt, # a[i]
+    DerefArrayAt, # a[i] where `a` is a PtrArray; `a[][i]`
+    FieldAt, # obj.field
+    DerefFieldAt, # obj[].field
+
+    Load, # a[]
+    Store, # a[] = b
+    Asgn,  # a = b
+    SetExc,
+    TestExc,
+
+    CheckedRange,
+    CheckedIndex,
+
+    Call,
+    IndirectCall,
+    CheckedCall, # call that can raise
+    CheckedIndirectCall, # call that can raise
+    CheckedAdd, # with overflow checking etc.
+    CheckedSub,
+    CheckedMul,
+    CheckedDiv,
+    CheckedMod,
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod,
+    BitShl,
+    BitShr,
+    BitAnd,
+    BitOr,
+    BitXor,
+    BitNot,
+    BoolNot,
+    Eq,
+    Le,
+    Lt,
+    Cast,
+    NumberConv,
+    CheckedObjConv,
+    ObjConv,
+    TestOf,
+    Emit,
+    ProcDecl,
+    ForeignProcDecl,
+    PragmaPair
+
+type
+  PragmaKey* = enum
+    FastCall, StdCall, CDeclCall, SafeCall, SysCall, InlineCall, NoinlineCall, ThisCall, NoCall,
+    CoreName,
+    ExternName,
+    HeaderImport,
+    DllImport,
+    DllExport,
+    ObjExport
+
+const
+  LastAtomicValue = GotoLoop
+
+  OpcodeBits = 8'u32
+  OpcodeMask = (1'u32 shl OpcodeBits) - 1'u32
+
+  ValueProducingAtoms = {ImmediateVal, IntVal, StrVal, SymUse, NilVal}
+
+  ValueProducing* = {
+    ImmediateVal,
+    IntVal,
+    StrVal,
+    SymUse,
+    NilVal,
+    ModuleSymUse,
+    ArrayConstr,
+    ObjConstr,
+    CheckedAdd,
+    CheckedSub,
+    CheckedMul,
+    CheckedDiv,
+    CheckedMod,
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Mod,
+    BitShl,
+    BitShr,
+    BitAnd,
+    BitOr,
+    BitXor,
+    BitNot,
+    BoolNot,
+    Eq,
+    Le,
+    Lt,
+    Cast,
+    NumberConv,
+    CheckedObjConv,
+    ObjConv,
+    AddrOf,
+    Load,
+    ArrayAt,
+    DerefArrayAt,
+    FieldAt,
+    DerefFieldAt,
+    TestOf
+  }
+
+type
+  Instr* = object     # 8 bytes
+    x: uint32
+    info*: PackedLineInfo
+
+template kind*(n: Instr): Opcode = Opcode(n.x and OpcodeMask)
+template operand(n: Instr): uint32 = (n.x shr OpcodeBits)
+
+template rawOperand*(n: Instr): uint32 = (n.x shr OpcodeBits)
+
+template toX(k: Opcode; operand: uint32): uint32 =
+  uint32(k) or (operand shl OpcodeBits)
+
+template toX(k: Opcode; operand: LitId): uint32 =
+  uint32(k) or (operand.uint32 shl OpcodeBits)
+
+type
+  Tree* = object
+    nodes: seq[Instr]
+
+  Values* = object
+    numbers: BiTable[int64]
+    strings: BiTable[string]
+
+type
+  PatchPos* = distinct int
+  NodePos* = distinct int
+
+const
+  InvalidPatchPos* = PatchPos(-1)
+
+proc isValid(p: PatchPos): bool {.inline.} = p.int != -1
+
+proc prepare*(tree: var Tree; info: PackedLineInfo; kind: Opcode): PatchPos =
+  result = PatchPos tree.nodes.len
+  tree.nodes.add Instr(x: toX(kind, 1'u32), info: info)
+
+proc isAtom(tree: Tree; pos: int): bool {.inline.} = tree.nodes[pos].kind <= LastAtomicValue
+proc isAtom(tree: Tree; pos: NodePos): bool {.inline.} = tree.nodes[pos.int].kind <= LastAtomicValue
+
+proc patch*(tree: var Tree; pos: PatchPos) =
+  let pos = pos.int
+  let k = tree.nodes[pos].kind
+  assert k > LastAtomicValue
+  let distance = int32(tree.nodes.len - pos)
+  assert distance > 0
+  tree.nodes[pos].x = toX(k, cast[uint32](distance))
+
+template build*(tree: var Tree; info: PackedLineInfo; kind: Opcode; body: untyped) =
+  let pos = prepare(tree, info, kind)
+  body
+  patch(tree, pos)
+
+template buildTyped*(tree: var Tree; info: PackedLineInfo; kind: Opcode; typ: TypeId; body: untyped) =
+  let pos = prepare(tree, info, kind)
+  tree.addTyped info, typ
+  body
+  patch(tree, pos)
+
+proc len*(tree: Tree): int {.inline.} = tree.nodes.len
+
+template rawSpan(n: Instr): int = int(operand(n))
+
+proc nextChild(tree: Tree; pos: var int) {.inline.} =
+  if tree.nodes[pos].kind > LastAtomicValue:
+    assert tree.nodes[pos].operand > 0'u32
+    inc pos, tree.nodes[pos].rawSpan
+  else:
+    inc pos
+
+proc next*(tree: Tree; pos: var NodePos) {.inline.} = nextChild tree, int(pos)
+
+template firstSon*(n: NodePos): NodePos = NodePos(n.int+1)
+
+template skipTyped*(n: NodePos): NodePos = NodePos(n.int+2)
+
+iterator sons*(tree: Tree; n: NodePos): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+iterator sonsFrom1*(tree: Tree; n: NodePos): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  nextChild tree, pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+iterator sonsFromN*(tree: Tree; n: NodePos; toSkip = 2): NodePos =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  for i in 1..toSkip:
+    nextChild tree, pos
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+template `[]`*(t: Tree; n: NodePos): Instr = t.nodes[n.int]
+
+iterator sonsRest*(tree: Tree; parent, n: NodePos): NodePos =
+  var pos = n.int
+  assert tree[parent].kind > LastAtomicValue
+  let last = parent.int + tree[parent].rawSpan
+  while pos < last:
+    yield NodePos pos
+    nextChild tree, pos
+
+proc span(tree: Tree; pos: int): int {.inline.} =
+  if tree.nodes[pos].kind <= LastAtomicValue: 1 else: int(tree.nodes[pos].operand)
+
+proc copyTree*(dest: var Tree; src: Tree) =
+  let pos = 0
+  let L = span(src, pos)
+  let d = dest.nodes.len
+  dest.nodes.setLen(d + L)
+  assert L > 0
+  for i in 0..<L:
+    dest.nodes[d+i] = src.nodes[pos+i]
+
+proc sons2*(tree: Tree; n: NodePos): (NodePos, NodePos) {.inline.} =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  result = (NodePos a, NodePos b)
+
+proc sons3*(tree: Tree; n: NodePos): (NodePos, NodePos, NodePos) {.inline.} =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  result = (NodePos a, NodePos b, NodePos c)
+
+proc sons4*(tree: Tree; n: NodePos): (NodePos, NodePos, NodePos, NodePos) {.inline.} =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  let d = c + span(tree, c)
+  result = (NodePos a, NodePos b, NodePos c, NodePos d)
+
+proc sons5*(tree: Tree; n: NodePos): (NodePos, NodePos, NodePos, NodePos, NodePos) {.inline.} =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  let d = c + span(tree, c)
+  let e = d + span(tree, d)
+  result = (NodePos a, NodePos b, NodePos c, NodePos d, NodePos e)
+
+proc typeId*(ins: Instr): TypeId {.inline.} =
+  assert ins.kind == Typed
+  result = TypeId(ins.operand)
+
+proc symId*(ins: Instr): SymId {.inline.} =
+  assert ins.kind in {SymUse, SymDef}
+  result = SymId(ins.operand)
+
+proc immediateVal*(ins: Instr): int {.inline.} =
+  assert ins.kind == ImmediateVal
+  result = cast[int](ins.operand)
+
+proc litId*(ins: Instr): LitId {.inline.} =
+  assert ins.kind in {StrVal, IntVal}
+  result = LitId(ins.operand)
+
+
+type
+  LabelId* = distinct int
+
+proc `==`*(a, b: LabelId): bool {.borrow.}
+proc hash*(a: LabelId): Hash {.borrow.}
+
+proc label*(ins: Instr): LabelId {.inline.} =
+  assert ins.kind in {Label, LoopLabel, Goto, GotoLoop, CheckedGoto}
+  result = LabelId(ins.operand)
+
+proc newLabel*(labelGen: var int): LabelId {.inline.} =
+  result = LabelId labelGen
+  inc labelGen
+
+proc newLabels*(labelGen: var int; n: int): LabelId {.inline.} =
+  result = LabelId labelGen
+  inc labelGen, n
+
+proc addNewLabel*(t: var Tree; labelGen: var int; info: PackedLineInfo; k: Opcode): LabelId =
+  assert k in {Label, LoopLabel}
+  result = LabelId labelGen
+  t.nodes.add Instr(x: toX(k, uint32(result)), info: info)
+  inc labelGen
+
+proc gotoLabel*(t: var Tree; info: PackedLineInfo; k: Opcode; L: LabelId) =
+  assert k in {Goto, GotoLoop, CheckedGoto}
+  t.nodes.add Instr(x: toX(k, uint32(L)), info: info)
+
+proc addLabel*(t: var Tree; info: PackedLineInfo; k: Opcode; L: LabelId) {.inline.} =
+  assert k in {Label, LoopLabel, Goto, GotoLoop, CheckedGoto}
+  t.nodes.add Instr(x: toX(k, uint32(L)), info: info)
+
+proc addSymUse*(t: var Tree; info: PackedLineInfo; s: SymId) {.inline.} =
+  t.nodes.add Instr(x: toX(SymUse, uint32(s)), info: info)
+
+proc addSymDef*(t: var Tree; info: PackedLineInfo; s: SymId) {.inline.} =
+  t.nodes.add Instr(x: toX(SymDef, uint32(s)), info: info)
+
+proc addNop*(t: var Tree; info: PackedLineInfo) {.inline.} =
+  t.nodes.add Instr(x: toX(Nop, 0'u32), info: info)
+
+proc addTyped*(t: var Tree; info: PackedLineInfo; typ: TypeId) {.inline.} =
+  assert typ.int >= 0
+  t.nodes.add Instr(x: toX(Typed, uint32(typ)), info: info)
+
+proc addSummon*(t: var Tree; info: PackedLineInfo; s: SymId; typ: TypeId; opc = Summon) {.inline.} =
+  assert typ.int >= 0
+  assert opc in {Summon, SummonConst, SummonGlobal, SummonThreadLocal, SummonParam, SummonResult}
+  let x = prepare(t, info, opc)
+  t.nodes.add Instr(x: toX(Typed, uint32(typ)), info: info)
+  t.nodes.add Instr(x: toX(SymDef, uint32(s)), info: info)
+  patch t, x
+
+proc addImmediateVal*(t: var Tree; info: PackedLineInfo; x: int) =
+  assert x >= 0 and x < ((1 shl 32) - OpcodeBits.int)
+  t.nodes.add Instr(x: toX(ImmediateVal, uint32(x)), info: info)
+
+proc addPragmaId*(t: var Tree; info: PackedLineInfo; x: PragmaKey) =
+  t.nodes.add Instr(x: toX(PragmaId, uint32(x)), info: info)
+
+proc addIntVal*(t: var Tree; integers: var BiTable[int64]; info: PackedLineInfo; typ: TypeId; x: int64) =
+  buildTyped t, info, NumberConv, typ:
+    t.nodes.add Instr(x: toX(IntVal, uint32(integers.getOrIncl(x))), info: info)
+
+proc boolVal*(t: var Tree; integers: var BiTable[int64]; info: PackedLineInfo; b: bool) =
+  buildTyped t, info, NumberConv, Bool8Id:
+    t.nodes.add Instr(x: toX(IntVal, uint32(integers.getOrIncl(ord b))), info: info)
+
+proc addStrVal*(t: var Tree; strings: var BiTable[string]; info: PackedLineInfo; s: string) =
+  t.nodes.add Instr(x: toX(StrVal, uint32(strings.getOrIncl(s))), info: info)
+
+proc addStrLit*(t: var Tree; info: PackedLineInfo; s: LitId) =
+  t.nodes.add Instr(x: toX(StrVal, uint32(s)), info: info)
+
+proc addNilVal*(t: var Tree; info: PackedLineInfo; typ: TypeId) =
+  buildTyped t, info, NumberConv, typ:
+    t.nodes.add Instr(x: toX(NilVal, uint32(0)), info: info)
+
+proc store*(r: var RodFile; t: Tree) = storeSeq r, t.nodes
+proc load*(r: var RodFile; t: var Tree) = loadSeq r, t.nodes
+
+proc escapeToNimLit*(s: string; result: var string) =
+  result.add '"'
+  for c in items s:
+    if c < ' ' or int(c) >= 128:
+      result.add '\\'
+      result.addInt int(c)
+    elif c == '\\':
+      result.add r"\\"
+    elif c == '\n':
+      result.add r"\n"
+    elif c == '\r':
+      result.add r"\r"
+    elif c == '\t':
+      result.add r"\t"
+    else:
+      result.add c
+  result.add '"'
+
+type
+  SymNames* = object
+    s: seq[LitId]
+
+proc `[]=`*(t: var SymNames; key: SymId; val: LitId) =
+  let k = int(key)
+  if k >= t.s.len: t.s.setLen k+1
+  t.s[k] = val
+
+proc `[]`*(t: SymNames; key: SymId): LitId =
+  let k = int(key)
+  if k < t.s.len: result = t.s[k]
+  else: result = LitId(0)
+
+template localName(s: SymId): string =
+  let name = names[s]
+  if name != LitId(0):
+    strings[name]
+  else:
+    $s.int
+
+proc store*(r: var RodFile; t: SymNames) = storeSeq(r, t.s)
+proc load*(r: var RodFile; t: var SymNames) = loadSeq(r, t.s)
+
+proc toString*(t: Tree; pos: NodePos; strings: BiTable[string]; integers: BiTable[int64];
+               names: SymNames;
+               r: var string; nesting = 0) =
+  if r.len > 0 and r[r.len-1] notin {' ', '\n', '(', '[', '{'}:
+    r.add ' '
+
+  case t[pos].kind
+  of Nop: r.add "Nop"
+  of ImmediateVal:
+    r.add $t[pos].operand
+  of IntVal:
+    r.add "IntVal "
+    r.add $integers[LitId t[pos].operand]
+  of StrVal:
+    escapeToNimLit(strings[LitId t[pos].operand], r)
+  of SymDef:
+    r.add "SymDef "
+    r.add localName(SymId t[pos].operand)
+  of SymUse:
+    r.add "SymUse "
+    r.add localName(SymId t[pos].operand)
+  of PragmaId:
+    r.add $cast[PragmaKey](t[pos].operand)
+  of Typed:
+    r.add "T<"
+    r.add $t[pos].operand
+    r.add ">"
+  of NilVal:
+    r.add "NilVal"
+  of Label:
+    # undo the nesting:
+    var spaces = r.len-1
+    while spaces >= 0 and r[spaces] == ' ': dec spaces
+    r.setLen spaces+1
+    r.add "\n  L"
+    r.add $t[pos].operand
+  of Goto, CheckedGoto, LoopLabel, GotoLoop:
+    r.add $t[pos].kind
+    r.add " L"
+    r.add $t[pos].operand
+  else:
+    r.add $t[pos].kind
+    r.add "{\n"
+    for i in 0..<(nesting+1)*2: r.add ' '
+    for p in sons(t, pos):
+      toString t, p, strings, integers, names, r, nesting+1
+    r.add "\n"
+    for i in 0..<nesting*2: r.add ' '
+    r.add "}"
+
+proc allTreesToString*(t: Tree; strings: BiTable[string]; integers: BiTable[int64];
+                       names: SymNames;
+                       r: var string) =
+  var i = 0
+  while i < t.len:
+    toString t, NodePos(i), strings, integers, names, r
+    nextChild t, i
+
+type
+  Value* = distinct Tree
+
+proc prepare*(dest: var Value; info: PackedLineInfo; k: Opcode): PatchPos {.inline.} =
+  assert k in ValueProducing - ValueProducingAtoms
+  result = prepare(Tree(dest), info, k)
+
+proc patch*(dest: var Value; pos: PatchPos) {.inline.} =
+  patch(Tree(dest), pos)
+
+proc localToValue*(info: PackedLineInfo; s: SymId): Value =
+  result = Value(Tree())
+  Tree(result).addSymUse info, s
+
+proc hasValue*(v: Value): bool {.inline.} = Tree(v).len > 0
+
+proc isEmpty*(v: Value): bool {.inline.} = Tree(v).len == 0
+
+proc extractTemp*(v: Value): SymId =
+  if hasValue(v) and Tree(v)[NodePos 0].kind == SymUse:
+    result = SymId(Tree(v)[NodePos 0].operand)
+  else:
+    result = SymId(-1)
+
+proc copyTree*(dest: var Tree; src: Value) = copyTree dest, Tree(src)
+
+proc addImmediateVal*(t: var Value; info: PackedLineInfo; x: int) =
+  assert x >= 0 and x < ((1 shl 32) - OpcodeBits.int)
+  Tree(t).nodes.add Instr(x: toX(ImmediateVal, uint32(x)), info: info)
+
+template build*(tree: var Value; info: PackedLineInfo; kind: Opcode; body: untyped) =
+  let pos = prepare(Tree(tree), info, kind)
+  body
+  patch(tree, pos)
+
+proc addTyped*(t: var Value; info: PackedLineInfo; typ: TypeId) {.inline.} =
+  addTyped(Tree(t), info, typ)
+
+template buildTyped*(tree: var Value; info: PackedLineInfo; kind: Opcode; typ: TypeId; body: untyped) =
+  let pos = prepare(tree, info, kind)
+  tree.addTyped info, typ
+  body
+  patch(tree, pos)
+
+proc addStrVal*(t: var Value; strings: var BiTable[string]; info: PackedLineInfo; s: string) =
+  addStrVal(Tree(t), strings, info, s)
+
+proc addNilVal*(t: var Value; info: PackedLineInfo; typ: TypeId) =
+  addNilVal Tree(t), info, typ
+
+proc addIntVal*(t: var Value; integers: var BiTable[int64]; info: PackedLineInfo; typ: TypeId; x: int64) =
+  addIntVal Tree(t), integers, info, typ, x

compiler/nir/nirlineinfos.nim

@@ -0,0 +1,84 @@
+#
+#
+#           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, rodfiles] # for LitId
+
+type
+  PackedLineInfo* = distinct uint32
+
+  LineInfoManager* = object
+    aside: seq[(LitId, int32, int32)]
+
+const
+  NoLineInfo* = PackedLineInfo(0'u32)
+
+proc pack*(m: var LineInfoManager; file: LitId; line, col: int32): PackedLineInfo =
+  if file.uint32 <= FileMax.uint32 and line <= LineMax and col <= ColMax:
+    let col = if col < 0'i32: 0'u32 else: col.uint32
+    let line = if line < 0'i32: 0'u32 else: line.uint32
+    # use inline representation:
+    result = PackedLineInfo((file.uint32 shl 1'u32) or (line shl uint32(AsideBit + FileBits)) or
+      (col shl uint32(AsideBit + FileBits + LineBits)))
+  else:
+    result = PackedLineInfo((m.aside.len shl 1) or AsideBit)
+    m.aside.add (file, line, col)
+
+proc unpack*(m: LineInfoManager; i: PackedLineInfo): (LitId, int32, int32) =
+  let i = i.uint32
+  if (i and 1'u32) == 0'u32:
+    # inline representation:
+    result = (LitId((i shr 1'u32) and FileMax.uint32),
+      int32((i shr uint32(AsideBit + FileBits)) and LineMax.uint32),
+      int32((i shr uint32(AsideBit + FileBits + LineBits)) and ColMax.uint32))
+  else:
+    result = m.aside[int(i shr 1'u32)]
+
+proc getFileId*(m: LineInfoManager; i: PackedLineInfo): LitId =
+  result = unpack(m, i)[0]
+
+proc store*(r: var RodFile; m: LineInfoManager) = storeSeq(r, m.aside)
+proc load*(r: var RodFile; m: var LineInfoManager) = loadSeq(r, m.aside)
+
+when isMainModule:
+  var m = LineInfoManager(aside: @[])
+  for i in 0'i32..<16388'i32:
+    for col in 0'i32..<100'i32:
+      let packed = pack(m, LitId(1023), i, col)
+      let u = unpack(m, packed)
+      assert u[0] == LitId(1023)
+      assert u[1] == i
+      assert u[2] == col
+  echo m.aside.len

compiler/nir/nirslots.nim

@@ -0,0 +1,104 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Management of slots. Similar to "register allocation"
+## in lower level languages.
+
+import std / [assertions, tables]
+import nirtypes, nirinsts
+
+type
+  SlotManagerFlag* = enum
+    ReuseTemps,
+    ReuseVars
+  SlotKind* = enum
+    Temp, Perm
+  SlotManager* = object # "register allocator"
+    live: Table[SymId, (SlotKind, TypeId)]
+    dead: Table[TypeId, seq[SymId]]
+    flags: set[SlotManagerFlag]
+    inScope: seq[SymId]
+
+proc initSlotManager*(flags: set[SlotManagerFlag]): SlotManager {.inline.} =
+  SlotManager(flags: flags)
+
+proc allocRaw(m: var SlotManager; t: TypeId; f: SlotManagerFlag; k: SlotKind;
+              symIdgen: var int32): SymId {.inline.} =
+  if f in m.flags and m.dead.hasKey(t) and m.dead[t].len > 0:
+    result = m.dead[t].pop()
+  else:
+    inc symIdgen
+    result = SymId(symIdgen)
+    m.inScope.add result
+  m.live[result] = (k, t)
+
+proc allocTemp*(m: var SlotManager; t: TypeId; symIdgen: var int32): SymId {.inline.} =
+  result = allocRaw(m, t, ReuseTemps, Temp, symIdgen)
+
+proc allocVar*(m: var SlotManager; t: TypeId; symIdgen: var int32): SymId {.inline.} =
+  result = allocRaw(m, t, ReuseVars, Perm, symIdgen)
+
+proc freeLoc*(m: var SlotManager; s: SymId) =
+  let t = m.live.getOrDefault(s)
+  assert t[1].int != 0
+  m.live.del s
+  m.dead.mgetOrPut(t[1], @[]).add s
+
+proc freeTemp*(m: var SlotManager; s: SymId) =
+  let t = m.live.getOrDefault(s)
+  if t[1].int != 0 and t[0] == Temp:
+    m.live.del s
+    m.dead.mgetOrPut(t[1], @[]).add s
+
+iterator stillAlive*(m: SlotManager): (SymId, TypeId) =
+  for k, v in pairs(m.live):
+    yield (k, v[1])
+
+proc getType*(m: SlotManager; s: SymId): TypeId {.inline.} = m.live[s][1]
+
+proc openScope*(m: var SlotManager) =
+  m.inScope.add SymId(-1) # add marker
+
+proc closeScope*(m: var SlotManager) =
+  var i = m.inScope.len - 1
+  while i >= 0:
+    if m.inScope[i] == SymId(-1):
+      m.inScope.setLen i
+      break
+    dec i
+
+when isMainModule:
+  var symIdgen: int32
+  var m = initSlotManager({ReuseTemps})
+
+  var g = initTypeGraph(Literals())
+
+  let a = g.openType ArrayTy
+  g.addBuiltinType Int8Id
+  g.addArrayLen 5
+  let finalArrayType = finishType(g, a)
+
+  let obj = g.openType ObjectDecl
+  g.addName "MyType"
+
+  g.addField "p", finalArrayType, 0
+  let objB = finishType(g, obj)
+
+  let x = m.allocTemp(objB, symIdgen)
+  assert x.int == 0
+
+  let y = m.allocTemp(objB, symIdgen)
+  assert y.int == 1
+
+  let z = m.allocTemp(Int8Id, symIdgen)
+  assert z.int == 2
+
+  m.freeLoc y
+  let y2 = m.allocTemp(objB, symIdgen)
+  assert y2.int == 1

compiler/nir/nirtypes.nim

@@ -0,0 +1,475 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Type system for NIR. Close to C's type system but without its quirks.
+
+import std / [assertions, hashes]
+import .. / ic / [bitabs, rodfiles]
+
+type
+  NirTypeKind* = enum
+    VoidTy, IntTy, UIntTy, FloatTy, BoolTy, CharTy, NameVal,
+    IntVal, SizeVal, AlignVal, OffsetVal,
+    AnnotationVal,
+    ObjectTy,
+    UnionTy,
+    VarargsTy, # the `...` in a C prototype; also the last "atom"
+    APtrTy, # pointer to aliasable memory
+    UPtrTy, # pointer to unique/unaliasable memory
+    AArrayPtrTy, # pointer to array of aliasable memory
+    UArrayPtrTy, # pointer to array of unique/unaliasable memory
+    ArrayTy,
+    LastArrayTy, # array of unspecified size as a last field inside an object
+    ProcTy,
+    ObjectDecl,
+    UnionDecl,
+    FieldDecl
+
+const
+  TypeKindBits = 8'u32
+  TypeKindMask = (1'u32 shl TypeKindBits) - 1'u32
+
+type
+  TypeNode* = object     # 4 bytes
+    x: uint32
+
+template kind*(n: TypeNode): NirTypeKind = NirTypeKind(n.x and TypeKindMask)
+template operand(n: TypeNode): uint32 = (n.x shr TypeKindBits)
+
+proc integralBits*(n: TypeNode): int {.inline.} =
+  # Number of bits in the IntTy, etc. Only valid for integral types.
+  assert n.kind in {IntTy, UIntTy, FloatTy, BoolTy, CharTy}
+  result = int(n.operand)
+
+template toX(k: NirTypeKind; operand: uint32): uint32 =
+  uint32(k) or (operand shl TypeKindBits)
+
+template toX(k: NirTypeKind; operand: LitId): uint32 =
+  uint32(k) or (operand.uint32 shl TypeKindBits)
+
+type
+  TypeId* = distinct int
+
+proc `==`*(a, b: TypeId): bool {.borrow.}
+proc hash*(a: TypeId): Hash {.borrow.}
+
+type
+  Literals* = ref object
+    strings*: BiTable[string]
+    numbers*: BiTable[int64]
+
+  TypeGraph* = object
+    nodes: seq[TypeNode]
+    lit: Literals
+
+const
+  VoidId* = TypeId 0
+  Bool8Id* = TypeId 1
+  Char8Id* = TypeId 2
+  Int8Id* = TypeId 3
+  Int16Id* = TypeId 4
+  Int32Id* = TypeId 5
+  Int64Id* = TypeId 6
+  UInt8Id* = TypeId 7
+  UInt16Id* = TypeId 8
+  UInt32Id* = TypeId 9
+  UInt64Id* = TypeId 10
+  Float32Id* = TypeId 11
+  Float64Id* = TypeId 12
+  VoidPtrId* = TypeId 13
+  LastBuiltinId* = 13
+
+proc initTypeGraph*(lit: Literals): TypeGraph =
+  result = TypeGraph(nodes: @[
+    TypeNode(x: toX(VoidTy, 0'u32)),
+    TypeNode(x: toX(BoolTy, 8'u32)),
+    TypeNode(x: toX(CharTy, 8'u32)),
+    TypeNode(x: toX(IntTy, 8'u32)),
+    TypeNode(x: toX(IntTy, 16'u32)),
+    TypeNode(x: toX(IntTy, 32'u32)),
+    TypeNode(x: toX(IntTy, 64'u32)),
+    TypeNode(x: toX(UIntTy, 8'u32)),
+    TypeNode(x: toX(UIntTy, 16'u32)),
+    TypeNode(x: toX(UIntTy, 32'u32)),
+    TypeNode(x: toX(UIntTy, 64'u32)),
+    TypeNode(x: toX(FloatTy, 32'u32)),
+    TypeNode(x: toX(FloatTy, 64'u32)),
+    TypeNode(x: toX(APtrTy, 2'u32)),
+    TypeNode(x: toX(VoidTy, 0'u32))
+  ], lit: lit)
+  assert result.nodes.len == LastBuiltinId+2
+
+type
+  TypePatchPos* = distinct int
+
+const
+  InvalidTypePatchPos* = TypePatchPos(-1)
+  LastAtomicValue = VarargsTy
+
+proc isValid(p: TypePatchPos): bool {.inline.} = p.int != -1
+
+proc prepare(tree: var TypeGraph; kind: NirTypeKind): TypePatchPos =
+  result = TypePatchPos tree.nodes.len
+  tree.nodes.add TypeNode(x: toX(kind, 1'u32))
+
+proc isAtom(tree: TypeGraph; pos: int): bool {.inline.} = tree.nodes[pos].kind <= LastAtomicValue
+proc isAtom(tree: TypeGraph; pos: TypeId): bool {.inline.} = tree.nodes[pos.int].kind <= LastAtomicValue
+
+proc patch(tree: var TypeGraph; pos: TypePatchPos) =
+  let pos = pos.int
+  let k = tree.nodes[pos].kind
+  assert k > LastAtomicValue
+  let distance = int32(tree.nodes.len - pos)
+  assert distance > 0
+  tree.nodes[pos].x = toX(k, cast[uint32](distance))
+
+proc len*(tree: TypeGraph): int {.inline.} = tree.nodes.len
+
+template rawSpan(n: TypeNode): int = int(operand(n))
+
+proc nextChild(tree: TypeGraph; pos: var int) {.inline.} =
+  if tree.nodes[pos].kind > LastAtomicValue:
+    assert tree.nodes[pos].operand > 0'u32
+    inc pos, tree.nodes[pos].rawSpan
+  else:
+    inc pos
+
+iterator sons*(tree: TypeGraph; n: TypeId): TypeId =
+  var pos = n.int
+  assert tree.nodes[pos].kind > LastAtomicValue
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  while pos < last:
+    yield TypeId pos
+    nextChild tree, pos
+
+template `[]`*(t: TypeGraph; n: TypeId): TypeNode = t.nodes[n.int]
+
+proc elementType*(tree: TypeGraph; n: TypeId): TypeId {.inline.} =
+  assert tree[n].kind in {APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy, ArrayTy, LastArrayTy}
+  result = TypeId(n.int+1)
+
+proc litId*(n: TypeNode): LitId {.inline.} =
+  assert n.kind in {NameVal, IntVal, SizeVal, AlignVal, OffsetVal, AnnotationVal, ObjectTy, UnionTy}
+  result = LitId(n.operand)
+
+proc kind*(tree: TypeGraph; n: TypeId): NirTypeKind {.inline.} = tree[n].kind
+
+proc span(tree: TypeGraph; pos: int): int {.inline.} =
+  if tree.nodes[pos].kind <= LastAtomicValue: 1 else: int(tree.nodes[pos].operand)
+
+proc sons2(tree: TypeGraph; n: TypeId): (TypeId, TypeId) =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  result = (TypeId a, TypeId b)
+
+proc sons3(tree: TypeGraph; n: TypeId): (TypeId, TypeId, TypeId) =
+  assert(not isAtom(tree, n.int))
+  let a = n.int+1
+  let b = a + span(tree, a)
+  let c = b + span(tree, b)
+  result = (TypeId a, TypeId b, TypeId c)
+
+proc arrayName*(tree: TypeGraph; n: TypeId): TypeId {.inline.} =
+  assert tree[n].kind == ArrayTy
+  let (_, _, c) = sons3(tree, n)
+  result = c
+
+proc arrayLen*(tree: TypeGraph; n: TypeId): BiggestInt =
+  assert tree[n].kind == ArrayTy
+  let (_, b) = sons2(tree, n)
+  result = tree.lit.numbers[LitId tree[b].operand]
+
+proc returnType*(tree: TypeGraph; n: TypeId): (TypeId, TypeId) =
+  # Returns the positions of the return type + calling convention.
+  var pos = n.int
+  assert tree.nodes[pos].kind == ProcTy
+  let a = n.int+1
+  let b = a + span(tree, a)
+  result = (TypeId b, TypeId a) # not a typo, order is reversed
+
+iterator params*(tree: TypeGraph; n: TypeId): TypeId =
+  var pos = n.int
+  assert tree.nodes[pos].kind == ProcTy
+  let last = pos + tree.nodes[pos].rawSpan
+  inc pos
+  nextChild tree, pos
+  nextChild tree, pos
+  while pos < last:
+    yield TypeId pos
+    nextChild tree, pos
+
+proc openType*(tree: var TypeGraph; kind: NirTypeKind): TypePatchPos =
+  assert kind in {APtrTy, UPtrTy, AArrayPtrTy, UArrayPtrTy,
+    ArrayTy, LastArrayTy, ProcTy, ObjectDecl, UnionDecl,
+    FieldDecl}
+  result = prepare(tree, kind)
+
+template typeInvariant(p: TypePatchPos) =
+  when false:
+    if tree[TypeId(p)].kind == FieldDecl:
+      var k = 0
+      for ch in sons(tree, TypeId(p)):
+        inc k
+      assert k > 2, "damn! " & $k
+
+proc sealType*(tree: var TypeGraph; p: TypePatchPos) =
+  patch tree, p
+  typeInvariant(p)
+
+proc finishType*(tree: var TypeGraph; p: TypePatchPos): TypeId =
+  # Search for an existing instance of this type in
+  # order to reduce memory consumption:
+  patch tree, p
+  typeInvariant(p)
+
+  let s = span(tree, p.int)
+  var i = 0
+  while i < p.int:
+    if tree.nodes[i].x == tree.nodes[p.int].x:
+      var isMatch = true
+      for j in 1..<s:
+        if tree.nodes[j+i].x == tree.nodes[j+p.int].x:
+          discard "still a match"
+        else:
+          isMatch = false
+          break
+      if isMatch:
+        if p.int+s == tree.len:
+          setLen tree.nodes, p.int
+        return TypeId(i)
+    nextChild tree, i
+  result = TypeId(p)
+
+proc nominalType*(tree: var TypeGraph; kind: NirTypeKind; name: string): TypeId =
+  assert kind in {ObjectTy, UnionTy}
+  let content = TypeNode(x: toX(kind, tree.lit.strings.getOrIncl(name)))
+  for i in 0..<tree.len:
+    if tree.nodes[i].x == content.x:
+      return TypeId(i)
+  result = TypeId tree.nodes.len
+  tree.nodes.add content
+
+proc addNominalType*(tree: var TypeGraph; kind: NirTypeKind; name: string) =
+  assert kind in {ObjectTy, UnionTy}
+  tree.nodes.add TypeNode(x: toX(kind, tree.lit.strings.getOrIncl(name)))
+
+proc getTypeTag*(tree: TypeGraph; t: TypeId): string =
+  assert tree[t].kind in {ObjectTy, UnionTy}
+  result = tree.lit.strings[LitId tree[t].operand]
+
+proc addVarargs*(tree: var TypeGraph) =
+  tree.nodes.add TypeNode(x: toX(VarargsTy, 0'u32))
+
+proc getFloat128Type*(tree: var TypeGraph): TypeId =
+  result = TypeId tree.nodes.len
+  tree.nodes.add TypeNode(x: toX(FloatTy, 128'u32))
+
+proc addBuiltinType*(g: var TypeGraph; id: TypeId) =
+  g.nodes.add g[id]
+
+template firstSon*(n: TypeId): TypeId = TypeId(n.int+1)
+
+proc addType*(g: var TypeGraph; t: TypeId) =
+  # We cannot simply copy `*Decl` nodes. We have to introduce `*Ty` nodes instead:
+  if g[t].kind in {ObjectDecl, UnionDecl}:
+    assert g[t.firstSon].kind == NameVal
+    let name = LitId g[t.firstSon].operand
+    if g[t].kind == ObjectDecl:
+      g.nodes.add TypeNode(x: toX(ObjectTy, name))
+    else:
+      g.nodes.add TypeNode(x: toX(UnionTy, name))
+  else:
+    let pos = t.int
+    let L = span(g, pos)
+    let d = g.nodes.len
+    g.nodes.setLen(d + L)
+    assert L > 0
+    for i in 0..<L:
+      g.nodes[d+i] = g.nodes[pos+i]
+
+proc addArrayLen*(g: var TypeGraph; len: int64) =
+  g.nodes.add TypeNode(x: toX(IntVal, g.lit.numbers.getOrIncl(len)))
+
+proc addSize*(g: var TypeGraph; s: int64) =
+  g.nodes.add TypeNode(x: toX(SizeVal, g.lit.numbers.getOrIncl(s)))
+
+proc addOffset*(g: var TypeGraph; offset: int64) =
+  g.nodes.add TypeNode(x: toX(OffsetVal, g.lit.numbers.getOrIncl(offset)))
+
+proc addAlign*(g: var TypeGraph; a: int64) =
+  g.nodes.add TypeNode(x: toX(AlignVal, g.lit.numbers.getOrIncl(a)))
+
+proc addName*(g: var TypeGraph; name: string) =
+  g.nodes.add TypeNode(x: toX(NameVal, g.lit.strings.getOrIncl(name)))
+
+proc addAnnotation*(g: var TypeGraph; name: string) =
+  g.nodes.add TypeNode(x: toX(NameVal, g.lit.strings.getOrIncl(name)))
+
+proc addField*(g: var TypeGraph; name: string; typ: TypeId; offset: int64) =
+  let f = g.openType FieldDecl
+  g.addType typ
+  g.addOffset offset
+  g.addName name
+  sealType(g, f)
+
+proc ptrTypeOf*(g: var TypeGraph; t: TypeId): TypeId =
+  let f = g.openType APtrTy
+  g.addType t
+  result = finishType(g, f)
+
+proc arrayPtrTypeOf*(g: var TypeGraph; t: TypeId): TypeId =
+  let f = g.openType AArrayPtrTy
+  g.addType t
+  result = finishType(g, f)
+
+proc store*(r: var RodFile; g: TypeGraph) =
+  storeSeq r, g.nodes
+
+proc load*(r: var RodFile; g: var TypeGraph) =
+  loadSeq r, g.nodes
+
+proc toString*(dest: var string; g: TypeGraph; i: TypeId) =
+  case g[i].kind
+  of VoidTy: dest.add "void"
+  of IntTy:
+    dest.add "i"
+    dest.addInt g[i].operand
+  of UIntTy:
+    dest.add "u"
+    dest.addInt g[i].operand
+  of FloatTy:
+    dest.add "f"
+    dest.addInt g[i].operand
+  of BoolTy:
+    dest.add "b"
+    dest.addInt g[i].operand
+  of CharTy:
+    dest.add "c"
+    dest.addInt g[i].operand
+  of NameVal, AnnotationVal:
+    dest.add g.lit.strings[LitId g[i].operand]
+  of IntVal, SizeVal, AlignVal, OffsetVal:
+    dest.add $g[i].kind
+    dest.add ' '
+    dest.add $g.lit.numbers[LitId g[i].operand]
+  of VarargsTy:
+    dest.add "..."
+  of APtrTy:
+    dest.add "aptr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of UPtrTy:
+    dest.add "uptr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of AArrayPtrTy:
+    dest.add "aArrayPtr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of UArrayPtrTy:
+    dest.add "uArrayPtr["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of ArrayTy:
+    dest.add "Array["
+    let (elems, len, name) = g.sons3(i)
+    toString(dest, g, elems)
+    dest.add ", "
+    toString(dest, g, len)
+    dest.add ", "
+    toString(dest, g, name)
+    dest.add "]"
+  of LastArrayTy:
+    # array of unspecified size as a last field inside an object
+    dest.add "LastArrayTy["
+    toString(dest, g, g.elementType(i))
+    dest.add "]"
+  of ObjectTy:
+    dest.add "object "
+    dest.add g.lit.strings[LitId g[i].operand]
+  of UnionTy:
+    dest.add "union "
+    dest.add g.lit.strings[LitId g[i].operand]
+  of ProcTy:
+    dest.add "proc["
+    for t in sons(g, i):
+      dest.add ' '
+      toString(dest, g, t)
+    dest.add "]"
+  of ObjectDecl:
+    dest.add "object["
+    for t in sons(g, i):
+      toString(dest, g, t)
+      dest.add '\n'
+    dest.add "]"
+  of UnionDecl:
+    dest.add "union["
+    for t in sons(g, i):
+      toString(dest, g, t)
+      dest.add '\n'
+    dest.add "]"
+  of FieldDecl:
+    dest.add "field["
+    for t in sons(g, i):
+      toString(dest, g, t)
+      dest.add ' '
+    dest.add "]"
+
+    when false:
+      let (typ, offset, name) = g.sons3(i)
+      toString(dest, g, typ)
+      dest.add ' '
+      toString(dest, g, offset)
+      dest.add ' '
+      toString(dest, g, name)
+
+proc toString*(dest: var string; g: TypeGraph) =
+  var i = 0
+  while i < g.len:
+    dest.add "T<"
+    dest.addInt i
+    dest.add "> "
+    toString(dest, g, TypeId i)
+    dest.add '\n'
+    nextChild g, i
+
+iterator allTypes*(g: TypeGraph; start = 0): TypeId =
+  var i = start
+  while i < g.len:
+    yield TypeId i
+    nextChild g, i
+
+iterator allTypesIncludingInner*(g: TypeGraph; start = 0): TypeId =
+  var i = start
+  while i < g.len:
+    yield TypeId i
+    inc i
+
+proc `$`(g: TypeGraph): string =
+  result = ""
+  toString(result, g)
+
+when isMainModule:
+  var g = initTypeGraph(Literals())
+
+  let a = g.openType ArrayTy
+  g.addBuiltinType Int8Id
+  g.addArrayLen 5
+  g.addName "SomeArray"
+  let finalArrayType = finishType(g, a)
+
+  let obj = g.openType ObjectDecl
+  g.nodes.add TypeNode(x: toX(NameVal, g.lit.strings.getOrIncl("MyType")))
+
+  g.addField "p", finalArrayType, 0
+  sealType(g, obj)
+
+  echo g

compiler/nir/stringcases.nim

@@ -0,0 +1,200 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## included from ast2ir.nim
+
+#[
+
+case s
+of "abc", "abbd":
+  echo 1
+of "hah":
+  echo 2
+of "gah":
+  echo 3
+
+# we produce code like this:
+
+if s[0] <= 'a':
+  if s == "abc: goto L1
+  elif s == "abbd": goto L1
+else:
+  if s[2] <= 'h':
+    if s == "hah": goto L2
+    elif s == "gah": goto L3
+goto afterCase
+
+L1:
+  echo 1
+  goto afterCase
+L2:
+  echo 2
+  goto afterCase
+L3:
+  echo 3
+  goto afterCase
+
+afterCase: ...
+
+]#
+
+# We split the set of strings into 2 sets of roughly the same size.
+# The condition used for splitting is a (position, char) tuple.
+# Every string of length > position for which s[position] <= char is in one
+# set else it is in the other set.
+
+from std/sequtils import addUnique
+
+type
+  Key = (LitId, LabelId)
+
+proc splitValue(strings: BiTable[string]; a: openArray[Key]; position: int): (char, float) =
+  var cand: seq[char] = @[]
+  for t in items a:
+    let s = strings[t[0]]
+    if s.len > position: cand.addUnique s[position]
+
+  result = ('\0', -1.0)
+  for disc in items cand:
+    var hits = 0
+    for t in items a:
+      let s = strings[t[0]]
+      if s.len > position and s[position] <= disc:
+        inc hits
+    # the split is the better, the more `hits` is close to `a.len / 2`:
+    let grade = 100000.0 - abs(hits.float - a.len.float / 2.0)
+    if grade > result[1]:
+      result = (disc, grade)
+
+proc tryAllPositions(strings: BiTable[string]; a: openArray[Key]): (char, int) =
+  var m = 0
+  for t in items a:
+    m = max(m, strings[t[0]].len)
+
+  result = ('\0', -1)
+  var best = -1.0
+  for i in 0 ..< m:
+    let current = splitValue(strings, a, i)
+    if current[1] > best:
+      best = current[1]
+      result = (current[0], i)
+
+type
+  SearchKind = enum
+    LinearSearch, SplitSearch
+  SearchResult* = object
+    case kind: SearchKind
+    of LinearSearch:
+      a: seq[Key]
+    of SplitSearch:
+      span: int
+      best: (char, int)
+
+proc emitLinearSearch(strings: BiTable[string]; a: openArray[Key]; dest: var seq[SearchResult]) =
+  var d = SearchResult(kind: LinearSearch, a: @[])
+  for x in a: d.a.add x
+  dest.add d
+
+proc split(strings: BiTable[string]; a: openArray[Key]; dest: var seq[SearchResult]) =
+  if a.len <= 4:
+    emitLinearSearch strings, a, dest
+  else:
+    let best = tryAllPositions(strings, a)
+    var groupA: seq[Key] = @[]
+    var groupB: seq[Key] = @[]
+    for t in items a:
+      let s = strings[t[0]]
+      if s.len > best[1] and s[best[1]] <= best[0]:
+        groupA.add t
+      else:
+        groupB.add t
+    if groupA.len == 0 or groupB.len == 0:
+      emitLinearSearch strings, a, dest
+    else:
+      let toPatch = dest.len
+      dest.add SearchResult(kind: SplitSearch, span: 1, best: best)
+      split strings, groupA, dest
+      split strings, groupB, dest
+      let dist = dest.len - toPatch
+      assert dist > 0
+      dest[toPatch].span = dist
+
+proc toProblemDescription(c: var ProcCon; n: PNode): (seq[Key], LabelId) =
+  result = (@[], newLabels(c.labelGen, n.len))
+  assert n.kind == nkCaseStmt
+  for i in 1..<n.len:
+    let it = n[i]
+    let thisBranch = LabelId(result[1].int + i - 1)
+    if it.kind == nkOfBranch:
+      for j in 0..<it.len-1:
+        assert it[j].kind in {nkStrLit..nkTripleStrLit}
+        result[0].add (c.lit.strings.getOrIncl(it[j].strVal), thisBranch)
+
+proc decodeSolution(c: var ProcCon; dest: var Tree; s: seq[SearchResult]; i: int;
+                    selector: Value; info: PackedLineInfo) =
+  case s[i].kind
+  of SplitSearch:
+    let thenA = i+1
+    let elseA = thenA + (if s[thenA].kind == LinearSearch: 1 else: s[thenA].span)
+    let best = s[i].best
+
+    let tmp = getTemp(c, Bool8Id, info)
+    buildTyped dest, info, Asgn, Bool8Id:
+      dest.copyTree tmp
+      buildTyped dest, info, Call, Bool8Id:
+        c.addUseCodegenProc dest, "nimStrAtLe", info
+        dest.copyTree selector
+        dest.addIntVal c.lit.numbers, info, c.m.nativeIntId, best[1]
+        dest.addIntVal c.lit.numbers, info, Char8Id, best[0].int
+
+    template then() =
+      c.decodeSolution dest, s, thenA, selector, info
+    template otherwise() =
+      c.decodeSolution dest, s, elseA, selector, info
+    buildIfThenElse tmp, then, otherwise
+    freeTemp c, tmp
+
+  of LinearSearch:
+    let tmp = getTemp(c, Bool8Id, info)
+    for x in s[i].a:
+      buildTyped dest, info, Asgn, Bool8Id:
+        dest.copyTree tmp
+        buildTyped dest, info, Call, Bool8Id:
+          c.addUseCodegenProc dest, "eqStrings", info
+          dest.copyTree selector
+          dest.addStrLit info, x[0]
+      buildIf tmp:
+        c.code.gotoLabel info, Goto, x[1]
+    freeTemp c, tmp
+
+proc genStringCase(c: var ProcCon; n: PNode; d: var Value) =
+  let (problem, firstBranch) = toProblemDescription(c, n)
+  var solution: seq[SearchResult] = @[]
+  split c.lit.strings, problem, solution
+
+  # XXX Todo move complex case selector into a temporary.
+  let selector = c.genx(n[0])
+
+  let info = toLineInfo(c, n.info)
+  decodeSolution c, c.code, solution, 0, selector, info
+
+  let lend = newLabel(c.labelGen)
+  c.code.addLabel info, Goto, lend
+  for i in 1..<n.len:
+    let it = n[i]
+    let thisBranch = LabelId(firstBranch.int + i - 1)
+    c.code.addLabel info, Label, thisBranch
+    if it.kind == nkOfBranch:
+      gen(c, it.lastSon, d)
+      c.code.addLabel info, Goto, lend
+    else:
+      gen(c, it.lastSon, d)
+
+  c.code.addLabel info, Label, lend
+  freeTemp c, selector

compiler/nir/types2ir.nim

@@ -0,0 +1,525 @@
+#
+#
+#           The Nim Compiler
+#        (c) Copyright 2023 Andreas Rumpf
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+import std / [assertions, tables, sets]
+import ".." / [ast, types, options, sighashes, modulegraphs]
+import nirtypes
+
+type
+  TypesCon* = object
+    processed: Table[ItemId, TypeId]
+    processedByName: Table[string, TypeId]
+    recursionCheck: HashSet[ItemId]
+    conf: ConfigRef
+    stringType: TypeId
+
+proc initTypesCon*(conf: ConfigRef): TypesCon =
+  TypesCon(conf: conf, stringType: TypeId(-1))
+
+proc mangle(c: var TypesCon; t: PType): string =
+  result = $sighashes.hashType(t, c.conf)
+
+template cached(c: var TypesCon; t: PType; body: untyped) =
+  result = c.processed.getOrDefault(t.itemId)
+  if result.int == 0:
+    body
+    c.processed[t.itemId] = result
+
+template cachedByName(c: var TypesCon; t: PType; body: untyped) =
+  let key = mangle(c, t)
+  result = c.processedByName.getOrDefault(key)
+  if result.int == 0:
+    body
+    c.processedByName[key] = result
+
+proc typeToIr*(c: var TypesCon; g: var TypeGraph; t: PType): TypeId
+
+proc collectFieldTypes(c: var TypesCon; g: var TypeGraph; n: PNode; dest: var Table[ItemId, TypeId]) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      collectFieldTypes(c, g, n[i], dest)
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    collectFieldTypes(c, g, n[0], dest)
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        collectFieldTypes c, g, lastSon(n[i]), dest
+      else: discard
+  of nkSym:
+    dest[n.sym.itemId] = typeToIr(c, g, n.sym.typ)
+  else:
+    assert false, "unknown node kind: " & $n.kind
+
+proc objectToIr(c: var TypesCon; g: var TypeGraph; n: PNode; fieldTypes: Table[ItemId, TypeId]; unionId: var int) =
+  case n.kind
+  of nkRecList:
+    for i in 0..<n.len:
+      objectToIr(c, g, n[i], fieldTypes, unionId)
+  of nkRecCase:
+    assert(n[0].kind == nkSym)
+    objectToIr(c, g, n[0], fieldTypes, unionId)
+    let u = openType(g, UnionDecl)
+    g.addName "u_" & $unionId
+    inc unionId
+    for i in 1..<n.len:
+      case n[i].kind
+      of nkOfBranch, nkElse:
+        let subObj = openType(g, ObjectDecl)
+        g.addName "uo_" & $unionId & "_" & $i
+        objectToIr c, g, lastSon(n[i]), fieldTypes, unionId
+        sealType(g, subObj)
+      else: discard
+    sealType(g, u)
+  of nkSym:
+    g.addField n.sym.name.s & "_" & $n.sym.position, fieldTypes[n.sym.itemId], n.sym.offset
+  else:
+    assert false, "unknown node kind: " & $n.kind
+
+proc objectToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  if t[0] != nil:
+    # ensure we emitted the base type:
+    discard typeToIr(c, g, t[0])
+
+  var unionId = 0
+  var fieldTypes = initTable[ItemId, TypeId]()
+  collectFieldTypes c, g, t.n, fieldTypes
+  let obj = openType(g, ObjectDecl)
+  g.addName mangle(c, t)
+  g.addSize c.conf.getSize(t)
+  g.addAlign c.conf.getAlign(t)
+
+  if t[0] != nil:
+    g.addNominalType(ObjectTy, mangle(c, t[0]))
+  else:
+    g.addBuiltinType VoidId # object does not inherit
+    if not lacksMTypeField(t):
+      let f2 = g.openType FieldDecl
+      let voidPtr = openType(g, APtrTy)
+      g.addBuiltinType(VoidId)
+      sealType(g, voidPtr)
+      g.addOffset 0 # type field is always at offset 0
+      g.addName "m_type"
+      sealType(g, f2) # FieldDecl
+
+  objectToIr c, g, t.n, fieldTypes, unionId
+  result = finishType(g, obj)
+
+proc objectHeaderToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  result = g.nominalType(ObjectTy, mangle(c, t))
+
+proc tupleToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  var fieldTypes = newSeq[TypeId](t.len)
+  for i in 0..<t.len:
+    fieldTypes[i] = typeToIr(c, g, t[i])
+  let obj = openType(g, ObjectDecl)
+  g.addName mangle(c, t)
+  g.addSize c.conf.getSize(t)
+  g.addAlign c.conf.getAlign(t)
+
+  var accum = OffsetAccum(maxAlign: 1)
+  for i in 0..<t.len:
+    let child = t[i]
+    g.addField "f_" & $i, fieldTypes[i], accum.offset
+
+    computeSizeAlign(c.conf, child)
+    accum.align(child.align)
+    accum.inc(int32(child.size))
+  result = finishType(g, obj)
+
+proc procToIr(c: var TypesCon; g: var TypeGraph; t: PType; addEnv = false): TypeId =
+  var fieldTypes = newSeq[TypeId](0)
+  for i in 0..<t.len:
+    if t[i] == nil or not isCompileTimeOnly(t[i]):
+      fieldTypes.add typeToIr(c, g, t[i])
+  let obj = openType(g, ProcTy)
+
+  case t.callConv
+  of ccNimCall, ccFastCall, ccClosure: g.addAnnotation "__fastcall"
+  of ccStdCall: g.addAnnotation "__stdcall"
+  of ccCDecl: g.addAnnotation "__cdecl"
+  of ccSafeCall: g.addAnnotation "__safecall"
+  of ccSysCall: g.addAnnotation "__syscall"
+  of ccInline: g.addAnnotation "__inline"
+  of ccNoInline: g.addAnnotation "__noinline"
+  of ccThisCall: g.addAnnotation "__thiscall"
+  of ccNoConvention: g.addAnnotation ""
+
+  for i in 0..<fieldTypes.len:
+    g.addType fieldTypes[i]
+
+  if addEnv:
+    let a = openType(g, APtrTy)
+    g.addBuiltinType(VoidId)
+    sealType(g, a)
+
+  if tfVarargs in t.flags:
+    g.addVarargs()
+  result = finishType(g, obj)
+
+proc nativeInt(c: TypesCon): TypeId =
+  case c.conf.target.intSize
+  of 2: result = Int16Id
+  of 4: result = Int32Id
+  else: result = Int64Id
+
+proc openArrayPayloadType*(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  let e = lastSon(t)
+  let elementType = typeToIr(c, g, e)
+  let arr = g.openType AArrayPtrTy
+  g.addType elementType
+  result = finishType(g, arr) # LastArrayTy
+
+proc openArrayToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  # object (a: ArrayPtr[T], len: int)
+  let e = lastSon(t)
+  let mangledBase = mangle(c, e)
+  let typeName = "NimOpenArray" & mangledBase
+
+  let elementType = typeToIr(c, g, e)
+  #assert elementType.int >= 0, typeToString(t)
+
+  let p = openType(g, ObjectDecl)
+  g.addName typeName
+  g.addSize c.conf.target.ptrSize*2
+  g.addAlign c.conf.target.ptrSize
+
+  let f = g.openType FieldDecl
+  let arr = g.openType AArrayPtrTy
+  g.addType elementType
+  sealType(g, arr) # LastArrayTy
+  g.addOffset 0
+  g.addName "data"
+  sealType(g, f) # FieldDecl
+
+  g.addField "len", c.nativeInt, c.conf.target.ptrSize
+
+  result = finishType(g, p) # ObjectDecl
+
+proc strPayloadType(c: var TypesCon; g: var TypeGraph): (string, TypeId) =
+  result = ("NimStrPayload", TypeId(-1))
+  let p = openType(g, ObjectDecl)
+  g.addName result[0]
+  g.addSize c.conf.target.ptrSize*2
+  g.addAlign c.conf.target.ptrSize
+
+  g.addField "cap", c.nativeInt, 0
+
+  let f = g.openType FieldDecl
+  let arr = g.openType LastArrayTy
+  g.addBuiltinType Char8Id
+  result[1] = finishType(g, arr) # LastArrayTy
+  g.addOffset c.conf.target.ptrSize # comes after the len field
+  g.addName "data"
+  sealType(g, f) # FieldDecl
+
+  sealType(g, p)
+
+proc strPayloadPtrType*(c: var TypesCon; g: var TypeGraph): (TypeId, TypeId) =
+  let (mangled, arrayType) = strPayloadType(c, g)
+  let ffp = g.openType APtrTy
+  g.addNominalType ObjectTy, mangled
+  result = (finishType(g, ffp), arrayType) # APtrTy
+
+proc stringToIr(c: var TypesCon; g: var TypeGraph): TypeId =
+  #[
+
+    NimStrPayload = object
+      cap: int
+      data: UncheckedArray[char]
+
+    NimStringV2 = object
+      len: int
+      p: ptr NimStrPayload
+
+  ]#
+  let payload = strPayloadType(c, g)
+
+  let str = openType(g, ObjectDecl)
+  g.addName "NimStringV2"
+  g.addSize c.conf.target.ptrSize*2
+  g.addAlign c.conf.target.ptrSize
+
+  g.addField "len", c.nativeInt, 0
+
+  let fp = g.openType FieldDecl
+  let ffp = g.openType APtrTy
+  g.addNominalType ObjectTy, "NimStrPayload"
+  sealType(g, ffp) # APtrTy
+  g.addOffset c.conf.target.ptrSize # comes after 'len' field
+  g.addName "p"
+  sealType(g, fp) # FieldDecl
+
+  result = finishType(g, str) # ObjectDecl
+
+proc seqPayloadType(c: var TypesCon; g: var TypeGraph; t: PType): (string, TypeId) =
+  #[
+    NimSeqPayload[T] = object
+      cap: int
+      data: UncheckedArray[T]
+  ]#
+  let e = lastSon(t)
+  result = (mangle(c, e), TypeId(-1))
+  let payloadName = "NimSeqPayload" & result[0]
+
+  let elementType = typeToIr(c, g, e)
+
+  let p = openType(g, ObjectDecl)
+  g.addName payloadName
+  g.addSize c.conf.target.intSize
+  g.addAlign c.conf.target.intSize
+
+  g.addField "cap", c.nativeInt, 0
+
+  let f = g.openType FieldDecl
+  let arr = g.openType LastArrayTy
+  g.addType elementType
+  # DO NOT USE `finishType` here as it is an inner type. This is subtle and we
+  # probably need an even better API here.
+  sealType(g, arr)
+  result[1] = TypeId(arr)
+
+  g.addOffset c.conf.target.ptrSize
+  g.addName "data"
+  sealType(g, f) # FieldDecl
+
+  sealType(g, p)
+
+proc seqPayloadPtrType*(c: var TypesCon; g: var TypeGraph; t: PType): (TypeId, TypeId) =
+  let (mangledBase, arrayType) = seqPayloadType(c, g, t)
+  let ffp = g.openType APtrTy
+  g.addNominalType ObjectTy, "NimSeqPayload" & mangledBase
+  result = (finishType(g, ffp), arrayType) # APtrTy
+
+proc seqToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  #[
+    NimSeqV2*[T] = object
+      len: int
+      p: ptr NimSeqPayload[T]
+  ]#
+  let (mangledBase, _) = seqPayloadType(c, g, t)
+
+  let sq = openType(g, ObjectDecl)
+  g.addName "NimSeqV2" & mangledBase
+  g.addSize c.conf.getSize(t)
+  g.addAlign c.conf.getAlign(t)
+
+  g.addField "len", c.nativeInt, 0
+
+  let fp = g.openType FieldDecl
+  let ffp = g.openType APtrTy
+  g.addNominalType ObjectTy, "NimSeqPayload" & mangledBase
+  sealType(g, ffp) # APtrTy
+  g.addOffset c.conf.target.ptrSize
+  g.addName "p"
+  sealType(g, fp) # FieldDecl
+
+  result = finishType(g, sq) # ObjectDecl
+
+
+proc closureToIr(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  # struct {fn(args, void* env), env}
+  # typedef struct {$n" &
+  #        "N_NIMCALL_PTR($2, ClP_0) $3;$n" &
+  #        "void* ClE_0;$n} $1;$n"
+  let mangledBase = mangle(c, t)
+  let typeName = "NimClosure" & mangledBase
+
+  let procType = procToIr(c, g, t, addEnv=true)
+
+  let p = openType(g, ObjectDecl)
+  g.addName typeName
+  g.addSize c.conf.getSize(t)
+  g.addAlign c.conf.getAlign(t)
+
+  let f = g.openType FieldDecl
+  g.addType procType
+  g.addOffset 0
+  g.addName "ClP_0"
+  sealType(g, f) # FieldDecl
+
+  let f2 = g.openType FieldDecl
+  let voidPtr = openType(g, APtrTy)
+  g.addBuiltinType(VoidId)
+  sealType(g, voidPtr)
+
+  g.addOffset c.conf.target.ptrSize
+  g.addName "ClE_0"
+  sealType(g, f2) # FieldDecl
+
+  result = finishType(g, p) # ObjectDecl
+
+proc bitsetBasetype*(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  let s = int(getSize(c.conf, t))
+  case s
+  of 1: result = UInt8Id
+  of 2: result = UInt16Id
+  of 4: result = UInt32Id
+  of 8: result = UInt64Id
+  else: result = UInt8Id
+
+proc typeToIr*(c: var TypesCon; g: var TypeGraph; t: PType): TypeId =
+  if t == nil: return VoidId
+  case t.kind
+  of tyInt:
+    case int(getSize(c.conf, t))
+    of 2: result = Int16Id
+    of 4: result = Int32Id
+    else: result = Int64Id
+  of tyInt8: result = Int8Id
+  of tyInt16: result = Int16Id
+  of tyInt32: result = Int32Id
+  of tyInt64: result = Int64Id
+  of tyFloat:
+    case int(getSize(c.conf, t))
+    of 4: result = Float32Id
+    else: result = Float64Id
+  of tyFloat32: result = Float32Id
+  of tyFloat64: result = Float64Id
+  of tyFloat128: result = getFloat128Type(g)
+  of tyUInt:
+    case int(getSize(c.conf, t))
+    of 2: result = UInt16Id
+    of 4: result = UInt32Id
+    else: result = UInt64Id
+  of tyUInt8: result = UInt8Id
+  of tyUInt16: result = UInt16Id
+  of tyUInt32: result = UInt32Id
+  of tyUInt64: result = UInt64Id
+  of tyBool: result = Bool8Id
+  of tyChar: result = Char8Id
+  of tyVoid: result = VoidId
+  of tySink, tyGenericInst, tyDistinct, tyAlias, tyOwned, tyRange:
+    result = typeToIr(c, g, t.lastSon)
+  of tyEnum:
+    if firstOrd(c.conf, t) < 0:
+      result = Int32Id
+    else:
+      case int(getSize(c.conf, t))
+      of 1: result = UInt8Id
+      of 2: result = UInt16Id
+      of 4: result = Int32Id
+      of 8: result = Int64Id
+      else: result = Int32Id
+  of tyOrdinal, tyGenericBody, tyGenericParam, tyInferred, tyStatic:
+    if t.len > 0:
+      result = typeToIr(c, g, t.lastSon)
+    else:
+      result = TypeId(-1)
+  of tyFromExpr:
+    if t.n != nil and t.n.typ != nil:
+      result = typeToIr(c, g, t.n.typ)
+    else:
+      result = TypeId(-1)
+  of tyArray:
+    cached(c, t):
+      var n = toInt64(lengthOrd(c.conf, t))
+      if n <= 0: n = 1   # make an array of at least one element
+      let elemType = typeToIr(c, g, t[1])
+      let a = openType(g, ArrayTy)
+      g.addType(elemType)
+      g.addArrayLen n
+      g.addName mangle(c, t)
+      result = finishType(g, a)
+  of tyPtr, tyRef:
+    cached(c, t):
+      let e = t.lastSon
+      if e.kind == tyUncheckedArray:
+        let elemType = typeToIr(c, g, e.lastSon)
+        let a = openType(g, AArrayPtrTy)
+        g.addType(elemType)
+        result = finishType(g, a)
+      else:
+        let elemType = typeToIr(c, g, t.lastSon)
+        let a = openType(g, APtrTy)
+        g.addType(elemType)
+        result = finishType(g, a)
+  of tyVar, tyLent:
+    cached(c, t):
+      let e = t.lastSon
+      if e.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
+        # skip the modifier, `var openArray` is a (ptr, len) pair too:
+        result = typeToIr(c, g, e)
+      else:
+        let elemType = typeToIr(c, g, e)
+        let a = openType(g, APtrTy)
+        g.addType(elemType)
+        result = finishType(g, a)
+  of tySet:
+    let s = int(getSize(c.conf, t))
+    case s
+    of 1: result = UInt8Id
+    of 2: result = UInt16Id
+    of 4: result = UInt32Id
+    of 8: result = UInt64Id
+    else:
+      # array[U8, s]
+      cached(c, t):
+        let a = openType(g, ArrayTy)
+        g.addType(UInt8Id)
+        g.addArrayLen s
+        g.addName mangle(c, t)
+        result = finishType(g, a)
+  of tyPointer, tyNil:
+    # tyNil can happen for code like: `const CRAP = nil` which we have in posix.nim
+    let a = openType(g, APtrTy)
+    g.addBuiltinType(VoidId)
+    result = finishType(g, a)
+  of tyObject:
+    # Objects are special as they can be recursive in Nim. This is easily solvable.
+    # We check if we are already "processing" t. If so, we produce `ObjectTy`
+    # instead of `ObjectDecl`.
+    cached(c, t):
+      if not c.recursionCheck.containsOrIncl(t.itemId):
+        result = objectToIr(c, g, t)
+      else:
+        result = objectHeaderToIr(c, g, t)
+  of tyTuple:
+    cachedByName(c, t):
+      result = tupleToIr(c, g, t)
+  of tyProc:
+    cached(c, t):
+      if t.callConv == ccClosure:
+        result = closureToIr(c, g, t)
+      else:
+        result = procToIr(c, g, t)
+  of tyVarargs, tyOpenArray:
+    cached(c, t):
+      result = openArrayToIr(c, g, t)
+  of tyString:
+    if c.stringType.int < 0:
+      result = stringToIr(c, g)
+      c.stringType = result
+    else:
+      result = c.stringType
+  of tySequence:
+    cachedByName(c, t):
+      result = seqToIr(c, g, t)
+  of tyCstring:
+    cached(c, t):
+      let a = openType(g, AArrayPtrTy)
+      g.addBuiltinType Char8Id
+      result = finishType(g, a)
+  of tyUncheckedArray:
+    # We already handled the `ptr UncheckedArray` in a special way.
+    cached(c, t):
+      let elemType = typeToIr(c, g, t.lastSon)
+      let a = openType(g, LastArrayTy)
+      g.addType(elemType)
+      result = finishType(g, a)
+  of tyUntyped, tyTyped:
+    # this avoids a special case for system.echo which is not a generic but
+    # uses `varargs[typed]`:
+    result = VoidId
+  of tyNone, tyEmpty, tyTypeDesc,
+     tyGenericInvocation, tyProxy, tyBuiltInTypeClass,
+     tyUserTypeClass, tyUserTypeClassInst, tyCompositeTypeClass,
+     tyAnd, tyOr, tyNot, tyAnything, tyConcept, tyIterable, tyForward:
+    result = TypeId(-1)

compiler/nodejs.nim

@@ -1,4 +1,4 @@
-import os
+import std/os
 
 proc findNodeJs*(): string {.inline.} =
   ## Find NodeJS executable and return it as a string.

compiler/optimizer.nim

@@ -12,11 +12,11 @@
 ## - recognize "all paths lead to 'wasMoved(x)'"
 
 import
-  ast, renderer, idents, intsets
+  ast, renderer, idents
 
 from trees import exprStructuralEquivalent
 
-import std/strutils
+import std/[strutils, intsets]
 
 const
   nfMarkForDeletion = nfNone # faster than a lookup table
@@ -66,7 +66,7 @@ proc mergeBasicBlockInfo(parent: var BasicBlock; this: BasicBlock) {.inline.} =
 proc wasMovedTarget(matches: var IntSet; branch: seq[PNode]; moveTarget: PNode): bool =
   result = false
   for i in 0..<branch.len:
-    if exprStructuralEquivalent(branch[i][1].skipAddr, moveTarget,
+    if exprStructuralEquivalent(branch[i][1].skipHiddenAddr, moveTarget,
                                 strictSymEquality = true):
       result = true
       matches.incl i
@@ -76,7 +76,7 @@ proc intersect(summary: var seq[PNode]; branch: seq[PNode]) =
   var i = 0
   var matches = initIntSet()
   while i < summary.len:
-    if wasMovedTarget(matches, branch, summary[i][1].skipAddr):
+    if wasMovedTarget(matches, branch, summary[i][1].skipHiddenAddr):
       inc i
     else:
       summary.del i
@@ -87,7 +87,7 @@ proc intersect(summary: var seq[PNode]; branch: seq[PNode]) =
 proc invalidateWasMoved(c: var BasicBlock; x: PNode) =
   var i = 0
   while i < c.wasMovedLocs.len:
-    if exprStructuralEquivalent(c.wasMovedLocs[i][1].skipAddr, x,
+    if exprStructuralEquivalent(c.wasMovedLocs[i][1].skipHiddenAddr, x,
                                 strictSymEquality = true):
       c.wasMovedLocs.del i
     else:
@@ -96,7 +96,7 @@ proc invalidateWasMoved(c: var BasicBlock; x: PNode) =
 proc wasMovedDestroyPair(c: var Con; b: var BasicBlock; d: PNode) =
   var i = 0
   while i < b.wasMovedLocs.len:
-    if exprStructuralEquivalent(b.wasMovedLocs[i][1].skipAddr, d[1].skipAddr,
+    if exprStructuralEquivalent(b.wasMovedLocs[i][1].skipHiddenAddr, d[1].skipHiddenAddr,
                                 strictSymEquality = true):
       b.wasMovedLocs[i].flags.incl nfMarkForDeletion
       c.somethingTodo = true
@@ -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: