bump NimVersion to 2.0.8

fixes #19977

(cherry picked from commit f7c6e04cfb)

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -71,6 +71,5 @@ 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 (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).
+        or at least try known past releases (eg `choosenim 1.2.0`).
       - [Please, consider a Donation for the Nim project.](https://nim-lang.org/donate.html)

.github/workflows/ci_bench.yml

@@ -21,10 +21,10 @@ jobs:
         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_docs.yml

@@ -47,7 +47,7 @@ jobs:
           - target: windows
             os: windows-2019
           - target: osx
-            os: macos-11
+            os: macos-12
 
     name: ${{ matrix.target }}
     runs-on: ${{ matrix.os }}

.github/workflows/ci_packages.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-20.04, macos-11]
+        os: [ubuntu-20.04, macos-12]
         cpu: [amd64]
         batch: ["allowed_failures", "0_3", "1_3", "2_3"] # list of `index_num`
     name: '${{ matrix.os }} (batch: ${{ matrix.batch }})'
@@ -32,10 +32,10 @@ jobs:
         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

@@ -21,10 +21,10 @@ jobs:
         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

@@ -29,10 +29,10 @@ jobs:
 #         vmImage: 'ubuntu-18.04'
 #         CPU: i386
       OSX_amd64:
-        vmImage: 'macOS-11'
+        vmImage: 'macOS-12'
         CPU: amd64
       OSX_amd64_cpp:
-        vmImage: 'macOS-11'
+        vmImage: 'macOS-12'
         CPU: amd64
         NIM_COMPILE_TO_CPP: true
       Windows_amd64_batch0_3:

changelog.md

@@ -11,6 +11,12 @@
 
 [//]: # "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:"
 
 
@@ -21,6 +27,41 @@
 
 
 
+- An experimental option `genericsOpenSym` has been added to allow captured
+  symbols in generic routine bodies to be replaced by symbols injected locally
+  by templates/macros at instantiation time. `bind` may be used to keep the
+  captured symbols over the injected ones regardless of enabling the option.
+
+  Since this change may affect runtime behavior, the experimental switch
+  `genericsOpenSym` needs to be enabled, and a warning is given in the case
+  where an injected symbol would replace a captured symbol not bound by `bind`
+  and the experimental switch isn't enabled.
+
+  ```nim
+  const value = "captured"
+  template foo(x: int, body: untyped) =
+    let value {.inject.} = "injected"
+    body
+
+  proc old[T](): string =
+    foo(123):
+      return value # warning: a new `value` has been injected, use `bind` or turn on `experimental:genericsOpenSym`
+  echo old[int]() # "captured"
+
+  {.experimental: "genericsOpenSym".}
+
+  proc bar[T](): string =
+    foo(123):
+      return value
+  assert bar[int]() == "injected" # previously it would be "captured"
+
+  proc baz[T](): string =
+    bind value
+    foo(123):
+      return value
+  assert baz[int]() == "captured"
+  ```
+
 ## Compiler changes
 
 

changelogs/changelog_2_0_0_details.md

@@ -72,7 +72,7 @@
 - `shallowCopy` and `shallow` are removed for ARC/ORC. Use `move` when possible or combine assignment and
 `sink` for optimization purposes.
 
-- The experimental `nimPreviewDotLikeOps` switch is going to be removed or deprecated because it didn't fullfill its promises.
+- The experimental `nimPreviewDotLikeOps` switch is going to be removed or deprecated because it didn't fulfill its promises.
 
 - The `{.this.}` pragma, deprecated since 0.19, has been removed.
 - `nil` literals can no longer be directly assigned to variables or fields of `distinct` pointer types. They must be converted instead.

changelogs/changelog_2_2_0.md

@@ -1,12 +0,0 @@
-# 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 --mm:orc -d:release"
+  const cmd = "./koch boot --gc: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

@@ -114,8 +114,6 @@ 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:
@@ -151,7 +149,7 @@ proc isPartOf*(a, b: PNode): TAnalysisResult =
       result = isPartOf(a[1], b[1])
     of nkObjUpConv, nkObjDownConv, nkCheckedFieldExpr:
       result = isPartOf(a[0], b[0])
-    else: result = arNo
+    else: discard
     # Calls return a new location, so a default of ``arNo`` is fine.
   else:
     # go down recursively; this is quite demanding:
@@ -167,7 +165,6 @@ 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
@@ -189,9 +186,7 @@ proc isPartOf*(a, b: PNode): TAnalysisResult =
         if isPartOf(a.typ, b.typ) != arNo:
           result = isPartOf(a[0], b)
           if result == arNo: result = arMaybe
-        else:
-          result = arNo
-      else: result = arNo
+      else: discard
     of nkObjConstr:
       result = arNo
       for i in 1..<b.len:
@@ -209,6 +204,4 @@ proc isPartOf*(a, b: PNode): TAnalysisResult =
     of nkBracket:
       if b.len > 0:
         result = isPartOf(a, b[0])
-      else:
-        result = arNo
-    else: result = arNo
+    else: discard

compiler/ast.nim

@@ -10,7 +10,7 @@
 # abstract syntax tree + symbol table
 
 import
-  lineinfos, hashes, options, ropes, idents, int128, tables
+  lineinfos, hashes, options, ropes, idents, int128, tables, wordrecg
 from strutils import toLowerAscii
 
 when defined(nimPreviewSlimSystem):
@@ -314,9 +314,8 @@ 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
-    sfToplevelDecl
+    sfWasGenSym       # symbol was 'gensym'ed
 
   TSymFlags* = set[TSymFlag]
 
@@ -349,7 +348,6 @@ 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
@@ -519,6 +517,7 @@ type
     nfFirstWrite # this node is a first write
     nfHasComment # node has a comment
     nfSkipFieldChecking # node skips field visable checking
+    nfOpenSym # node is a captured sym but can be overriden by local symbols
 
   TNodeFlags* = set[TNodeFlag]
   TTypeFlag* = enum   # keep below 32 for efficiency reasons (now: 47)
@@ -642,7 +641,7 @@ 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}.
@@ -902,6 +901,7 @@ 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.:
@@ -959,7 +959,7 @@ type
     kind*: TTypeKind          # kind of type
     callConv*: TCallingConvention # for procs
     flags*: TTypeFlags        # flags of the type
-    sons: TTypeSeq           # base types, etc.
+    sons*: TTypeSeq           # base types, etc.
     n*: PNode                 # node for types:
                               # for range types a nkRange node
                               # for record types a nkRecord node
@@ -1040,8 +1040,6 @@ 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
@@ -1092,7 +1090,8 @@ const
                                       nfIsRef, nfIsPtr, nfPreventCg, nfLL,
                                       nfFromTemplate, nfDefaultRefsParam,
                                       nfExecuteOnReload, nfLastRead,
-                                      nfFirstWrite, nfSkipFieldChecking}
+                                      nfFirstWrite, nfSkipFieldChecking,
+                                      nfOpenSym}
   namePos* = 0
   patternPos* = 1    # empty except for term rewriting macros
   genericParamsPos* = 2
@@ -1228,7 +1227,6 @@ 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
@@ -1248,8 +1246,6 @@ 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
@@ -1265,12 +1261,6 @@ 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 =
@@ -1500,7 +1490,7 @@ 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: raiseAssert $kind
+  else: doAssert false, $kind
   result.intVal = intVal
   result.typ = typ
 
@@ -1538,31 +1528,15 @@ proc `$`*(s: PSym): string =
   else:
     result = "<nil>"
 
-iterator items*(t: PType): PType =
-  for i in 0..<t.sons.len: yield t.sons[i]
-
-iterator pairs*(n: PType): tuple[i: int, n: PType] =
-  for i in 0..<n.sons.len: yield (i, n.sons[i])
-
-proc newType*(kind: TTypeKind, id: ItemId; owner: PSym, sons: seq[PType] = @[]): PType =
+proc newType*(kind: TTypeKind, id: ItemId; owner: PSym): PType =
   result = PType(kind: kind, owner: owner, size: defaultSize,
                  align: defaultAlignment, itemId: id,
-                 uniqueId: id, sons: sons)
+                 uniqueId: id)
   when false:
     if result.itemId.module == 55 and result.itemId.item == 2:
       echo "KNID ", kind
       writeStackTrace()
 
-template newType*(kind: TTypeKind, id: ItemId; owner: PSym, parent: PType): PType =
-  newType(kind, id, owner, parent.sons)
-
-proc newType*(prev: PType, sons: seq[PType]): PType =
-  result = prev
-  result.sons = sons
-
-proc addSon*(father, son: PType) =
-  # todo fixme: in IC, `son` might be nil
-  father.sons.add(son)
 
 proc mergeLoc(a: var TLoc, b: TLoc) =
   if a.k == low(typeof(a.k)): a.k = b.k
@@ -1628,13 +1602,19 @@ proc createModuleAlias*(s: PSym, idgen: IdGenerator, newIdent: PIdent, info: TLi
   result.loc = s.loc
   result.annex = s.annex
 
-proc initStrTable*(): TStrTable =
-  result = TStrTable(counter: 0)
-  newSeq(result.data, StartSize)
+proc initStrTable*(x: var TStrTable) =
+  x.counter = 0
+  newSeq(x.data, StartSize)
 
-proc initIdTable*(): TIdTable =
-  result = TIdTable(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 resetIdTable*(x: var TIdTable) =
   x.counter = 0
@@ -1642,17 +1622,17 @@ proc resetIdTable*(x: var TIdTable) =
   setLen(x.data, 0)
   setLen(x.data, StartSize)
 
-proc initObjectSet*(): TObjectSet =
-  result = TObjectSet(counter: 0)
-  newSeq(result.data, StartSize)
+proc initObjectSet*(x: var TObjectSet) =
+  x.counter = 0
+  newSeq(x.data, StartSize)
 
-proc initIdNodeTable*(): TIdNodeTable =
-  result = TIdNodeTable(counter: 0)
-  newSeq(result.data, StartSize)
+proc initIdNodeTable*(x: var TIdNodeTable) =
+  x.counter = 0
+  newSeq(x.data, StartSize)
 
-proc initNodeTable*(): TNodeTable =
-  result = TNodeTable(counter: 0)
-  newSeq(result.data, StartSize)
+proc initNodeTable*(x: var TNodeTable) =
+  x.counter = 0
+  newSeq(x.data, StartSize)
 
 proc skipTypes*(t: PType, kinds: TTypeKinds; maxIters: int): PType =
   result = t
@@ -1836,7 +1816,6 @@ 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
@@ -2038,11 +2017,9 @@ 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

compiler/astalgo.nim

@@ -109,7 +109,7 @@ type
     data*: TIIPairSeq
 
 
-proc initIITable*(x: var TIITable)
+proc initIiTable*(x: var TIITable)
 proc iiTableGet*(t: TIITable, key: int): int
 proc iiTablePut*(t: var TIITable, key, val: int)
 
@@ -197,7 +197,6 @@ 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)
@@ -227,11 +226,10 @@ 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
@@ -329,10 +327,8 @@ 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:
@@ -1067,7 +1063,6 @@ 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/astmsgs.nim

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

compiler/bitsets.nim

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

compiler/btrees.nim

@@ -38,7 +38,6 @@ 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!
@@ -46,7 +47,6 @@ 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]
@@ -83,12 +83,16 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
   if typ[0] != nil:
+    var flags: TAssignmentFlags = {}
+    if typ[0].kind in {tyOpenArray, tyVarargs}:
+      # perhaps generate no temp if the call doesn't have side effects
+      flags.incl needTempForOpenArray
     if isInvalidReturnType(p.config, typ):
       if params.len != 0: pl.add(", ")
       # beware of 'result = p(result)'. We may need to allocate a temporary:
       if d.k in {locTemp, locNone} or not preventNrvo(p, d.lode, le, ri):
         # Great, we can use 'd':
-        if d.k == locNone: d = getTemp(p, typ[0], needsInit=true)
+        if d.k == locNone: getTemp(p, typ[0], d, needsInit=true)
         elif d.k notin {locTemp} and not hasNoInit(ri):
           # reset before pass as 'result' var:
           discard "resetLoc(p, d)"
@@ -96,7 +100,8 @@ 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], needsInit=true)
+        var tmp: TLoc
+        getTemp(p, typ[0], tmp, needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         pl.add(");\n")
         line(p, cpsStmts, pl)
@@ -114,26 +119,30 @@ proc fixupCall(p: BProc, le, ri: PNode, d: var TLoc,
           excl d.flags, lfSingleUse
         else:
           if d.k == locNone and p.splitDecls == 0:
-            d = getTempCpp(p, typ[0], pl)
+            getTempCpp(p, typ[0], d, pl)
           else:
-            if d.k == locNone: d = getTemp(p, typ[0])
-            var list = initLoc(locCall, d.lode, OnUnknown)
+            if d.k == locNone: getTemp(p, typ[0], d)
+            var list: TLoc
+            initLoc(list, 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: d = getTemp(p, typ[0])
+        if d.k == locNone: getTemp(p, typ[0], d)
         assert(d.t != nil)        # generate an assignment to d:
-        var list = initLoc(locCall, d.lode, OnUnknown)
+        var list: TLoc
+        initLoc(list, locCall, d.lode, OnUnknown)
         list.r = pl
-        genAssignment(p, d, list, {}) # no need for deep copying
+        genAssignment(p, d, list, flags) # no need for deep copying
         if canRaise: raiseExit(p)
       else:
-        var tmp: TLoc = getTemp(p, typ[0], needsInit=true)
-        var list = initLoc(locCall, d.lode, OnUnknown)
+        var tmp: TLoc
+        getTemp(p, typ[0], tmp, needsInit=true)
+        var list: TLoc
+        initLoc(list, locCall, d.lode, OnUnknown)
         list.r = pl
-        genAssignment(p, tmp, list, {}) # no need for deep copying
+        genAssignment(p, tmp, list, flags) # no need for deep copying
         if canRaise: raiseExit(p)
         genAssignment(p, d, tmp, {})
   else:
@@ -153,15 +162,19 @@ proc reifiedOpenArray(n: PNode): bool {.inline.} =
     result = true
 
 proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareForMutation = false): (Rope, Rope) =
-  var a = initLocExpr(p, q[1])
-  var b = initLocExpr(p, q[2])
-  var c = initLocExpr(p, q[3])
+  var a, b, c: TLoc
+  initLocExpr(p, q[1], a)
+  initLocExpr(p, q[2], b)
+  initLocExpr(p, q[3], c)
   # but first produce the required index checks:
   if optBoundsCheck in p.options:
     genBoundsCheck(p, a, b, c)
   if prepareForMutation:
     linefmt(p, cpsStmts, "#nimPrepareStrMutationV2($1);$n", [byRefLoc(p, a)])
-  let ty = skipTypes(a.t, abstractVar+{tyPtr})
+  # bug #23321: In the function mapType, ptrs (tyPtr, tyVar, tyLent, tyRef)
+  # are mapped into ctPtrToArray, the dereference of which is skipped
+  # in the `genref`. We need to skip these ptrs here
+  let ty = skipTypes(a.t, abstractVar+{tyPtr, tyRef})
   let dest = getTypeDesc(p.module, destType)
   let lengthExpr = "($1)-($2)+1" % [rdLoc(c), rdLoc(b)]
   case ty.kind
@@ -200,7 +213,6 @@ proc genOpenArraySlice(p: BProc; q: PNode; formalType, destType: PType; prepareF
                   [rdLoc(a), rdLoc(b), dataField(p), dest, dataFieldAccessor(p, rdLoc(a))],
                 lengthExpr)
   else:
-    result = ("", "")
     internalError(p.config, "openArrayLoc: " & typeToString(a.t))
 
 proc openArrayLoc(p: BProc, formalType: PType, n: PNode; result: var Rope) =
@@ -220,7 +232,8 @@ 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)
+    var a: TLoc
+    initLocExpr(p, if n.kind == nkHiddenStdConv: n[1] else: n, a)
     case skipTypes(a.t, abstractVar+{tyStatic}).kind
     of tyOpenArray, tyVarargs:
       if reifiedOpenArray(n):
@@ -266,17 +279,18 @@ 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:
-    result = getTemp(p, a.lode.typ, needsInit=false)
+    getTemp(p, a.lode.typ, result, needsInit=false)
     genAssignment(p, result, a, {})
   else:
     result = a
 
 proc literalsNeedsTmp(p: BProc, a: TLoc): TLoc =
-  result = getTemp(p, a.lode.typ, needsInit=false)
+  getTemp(p, a.lode.typ, result, 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])
+  var a: TLoc
+  initLocExpr(p, n[0], a)
   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) =
@@ -288,14 +302,23 @@ proc genArg(p: BProc, n: PNode, param: PSym; call: PNode; result: var Rope; need
     openArrayLoc(p, param.typ, n, result)
   elif ccgIntroducedPtr(p.config, param, call[0].typ[0]) and 
     (optByRef notin param.options or not p.module.compileToCpp):
-    a = initLocExpr(p, n)
+    initLocExpr(p, n, a)
     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:
-    a = initLocExprSingleUse(p, n[0])
+    # bug #23748: we need to introduce a temporary here. The expression type
+    # will be a reference in C++ and we cannot create a temporary reference
+    # variable. Thus, we create a temporary pointer variable instead.
+    let needsIndirect = mapType(p.config, n[0].typ, mapTypeChooser(n[0]) == skParam) != ctArray
+    if needsIndirect:
+      n.typ = n.typ.exactReplica
+      n.typ.flags.incl tfVarIsPtr
+    initLocExprSingleUse(p, n, a)
+    a = withTmpIfNeeded(p, a, needsTmp)
+    if needsIndirect: a.flags.incl lfIndirect
     # 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]
@@ -306,7 +329,12 @@ proc genArg(p: BProc, n: PNode, param: PSym; call: PNode; result: var Rope; need
     else:
       addRdLoc(a, result)
   else:
-    a = initLocExprSingleUse(p, n)
+    initLocExprSingleUse(p, n, a)
+    if param.typ.kind in abstractPtrs:
+      let typ = skipTypes(param.typ, abstractPtrs)
+      if typ.sym != nil and sfImportc in typ.sym.flags:
+        a.r = "(($1) ($2))" %
+          [getTypeDesc(p.module, param.typ), rdCharLoc(a)]
     addRdLoc(withTmpIfNeeded(p, a, needsTmp), result)
   #assert result != nil
 
@@ -315,13 +343,12 @@ proc genArgNoParam(p: BProc, n: PNode; result: var Rope; needsTmp = false) =
   if n.kind == nkStringToCString:
     genArgStringToCString(p, n, result, needsTmp)
   else:
-    a = initLocExprSingleUse(p, n)
+    initLocExprSingleUse(p, n, a)
     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
@@ -377,21 +404,23 @@ 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]:
           needTmp[i - 1] = potentialAlias(n, potentialWrites)
       getPotentialWrites(ri[i], false, potentialWrites)
-    if ri[i].kind in {nkHiddenAddr, nkAddr}:
-      # Optimization: don't use a temp, if we would only take the address anyway
-      needTmp[i - 1] = false
+    when false:
+      # this optimization is wrong, see bug #23748
+      if ri[i].kind in {nkHiddenAddr, nkAddr}:
+        # Optimization: don't use a temp, if we would only take the address anyway
+        needTmp[i - 1] = false
 
   var oldLen = result.len
   for i in 1..<ri.len:
@@ -415,8 +444,9 @@ 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
-  var op: TLoc = initLocExpr(p, ri[0])
+  initLocExpr(p, ri[0], op)
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInstOwned)
   assert(typ.kind == tyProc)
@@ -438,7 +468,8 @@ 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])
+  var op: TLoc
+  initLocExpr(p, ri[0], op)
 
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInstOwned)
@@ -463,7 +494,7 @@ 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:
-          d = getTemp(p, typ[0], needsInit=true)
+          getTemp(p, typ[0], d, needsInit=true)
         elif d.k notin {locTemp} and not hasNoInit(ri):
           # reset before pass as 'result' var:
           discard "resetLoc(p, d)"
@@ -471,15 +502,17 @@ proc genClosureCall(p: BProc, le, ri: PNode, d: var TLoc) =
         genCallPattern()
         if canRaise: raiseExit(p)
       else:
-        var tmp: TLoc = getTemp(p, typ[0], needsInit=true)
+        var tmp: TLoc
+        getTemp(p, typ[0], tmp, needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         genCallPattern()
         if canRaise: raiseExit(p)
         genAssignment(p, d, tmp, {}) # no need for deep copying
     elif isHarmlessStore(p, canRaise, d):
-      if d.k == locNone: d = getTemp(p, typ[0])
+      if d.k == locNone: getTemp(p, typ[0], d)
       assert(d.t != nil)        # generate an assignment to d:
-      var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
+      var list: TLoc
+      initLoc(list, locCall, d.lode, OnUnknown)
       if tfIterator in typ.flags:
         list.r = PatIter % [rdLoc(op), pl, pl.addComma, rawProc]
       else:
@@ -487,9 +520,11 @@ 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])
+      var tmp: TLoc
+      getTemp(p, typ[0], tmp)
       assert(d.t != nil)        # generate an assignment to d:
-      var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
+      var list: TLoc
+      initLoc(list, locCall, d.lode, OnUnknown)
       if tfIterator in typ.flags:
         list.r = PatIter % [rdLoc(op), pl, pl.addComma, rawProc]
       else:
@@ -657,7 +692,7 @@ proc genPatternCall(p: BProc; ri: PNode; pat: string; typ: PType; result: var Ro
       inc j
       inc i
     of '\'':
-      var idx, stars: int = 0
+      var idx, stars: int
       if scanCppGenericSlot(pat, i, idx, stars):
         var t = resolveStarsInCppType(typ, idx, stars)
         if t == nil: result.add("void")
@@ -671,7 +706,8 @@ 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])
+  var op: TLoc
+  initLocExpr(p, ri[0], op)
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
   assert(typ.kind == tyProc)
@@ -693,9 +729,10 @@ proc genInfixCall(p: BProc, le, ri: PNode, d: var TLoc) =
         d.r = pl
         excl d.flags, lfSingleUse
       else:
-        if d.k == locNone: d = getTemp(p, typ[0])
+        if d.k == locNone: getTemp(p, typ[0], d)
         assert(d.t != nil)        # generate an assignment to d:
-        var list: TLoc = initLoc(locCall, d.lode, OnUnknown)
+        var list: TLoc
+        initLoc(list, locCall, d.lode, OnUnknown)
         list.r = pl
         genAssignment(p, d, list, {}) # no need for deep copying
     else:
@@ -715,7 +752,8 @@ 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])
+  var op: TLoc
+  initLocExpr(p, ri[0], op)
   var pl = "["
   # getUniqueType() is too expensive here:
   var typ = skipTypes(ri[0].typ, abstractInst)
@@ -757,22 +795,24 @@ 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: d = getTemp(p, typ[0], needsInit=true)
+        if d.k == locNone: getTemp(p, typ[0], d, 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], needsInit=true)
+        var tmp: TLoc
+        getTemp(p, typ[0], tmp, needsInit=true)
         pl.add(addrLoc(p.config, tmp))
         pl.add("];\n")
         line(p, cpsStmts, pl)
         genAssignment(p, d, tmp, {}) # no need for deep copying
     else:
       pl.add("]")
-      if d.k == locNone: d = getTemp(p, typ[0])
+      if d.k == locNone: getTemp(p, typ[0], d)
       assert(d.t != nil)        # generate an assignment to d:
-      var list: TLoc = initLoc(locCall, ri, OnUnknown)
+      var list: TLoc
+      initLoc(list, locCall, ri, OnUnknown)
       list.r = pl
       genAssignment(p, d, list, {}) # no need for deep copying
   else:

compiler/ccgreset.nim

@@ -57,7 +57,8 @@ 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))
+    var i: TLoc
+    getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt), i)
     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])
@@ -82,7 +83,7 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
       lineCg(p, cpsStmts, "$1.ClP_0 = NIM_NIL;$n", [accessor])
     else:
       lineCg(p, cpsStmts, "$1 = NIM_NIL;$n", [accessor])
-  of tyChar, tyBool, tyEnum, tyInt..tyUInt64:
+  of tyChar, tyBool, tyEnum, tyRange, tyInt..tyUInt64:
     lineCg(p, cpsStmts, "$1 = 0;$n", [accessor])
   of tyCstring, tyPointer, tyPtr, tyVar, tyLent:
     lineCg(p, cpsStmts, "$1 = NIM_NIL;$n", [accessor])
@@ -94,9 +95,9 @@ proc specializeResetT(p: BProc, accessor: Rope, typ: PType) =
     of ctInt8, ctInt16, ctInt32, ctInt64:
       lineCg(p, cpsStmts, "$1 = 0;$n", [accessor])
     else:
-      raiseAssert "unexpected set type kind"
+      doAssert false, "unexpected set type kind"
   of {tyNone, tyEmpty, tyNil, tyUntyped, tyTyped, tyGenericInvocation,
-      tyGenericParam, tyOrdinal, tyRange, tyOpenArray, tyForward, tyVarargs,
+      tyGenericParam, tyOrdinal, tyOpenArray, tyForward, tyVarargs,
       tyUncheckedArray, tyProxy, tyBuiltInTypeClass, tyUserTypeClass,
       tyUserTypeClassInst, tyCompositeTypeClass, tyAnd, tyOr, tyNot,
       tyAnything, tyStatic, tyFromExpr, tyConcept, tyVoid, tyIterable}:

compiler/ccgstmts.nim

@@ -50,7 +50,6 @@ 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
 
@@ -72,6 +71,7 @@ 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)
-  var tup = initLocExpr(p, n[^1])
+  initLocExpr(p, n[^1], tup)
   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]))
-    var field = initLoc(locExpr, vn, tup.storage)
+    initLoc(field, 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:
@@ -244,7 +244,8 @@ proc genGotoState(p: BProc, n: PNode) =
   # switch (x.state) {
   #   case 0: goto STATE0;
   # ...
-  var a: TLoc = initLocExpr(p, n[0])
+  var a: TLoc
+  initLocExpr(p, n[0], a)
   lineF(p, cpsStmts, "switch ($1) {$n", [rdLoc(a)])
   p.flags.incl beforeRetNeeded
   lineF(p, cpsStmts, "case -1:$n", [])
@@ -263,13 +264,13 @@ proc genGotoState(p: BProc, n: PNode) =
 
 proc genBreakState(p: BProc, n: PNode, d: var TLoc) =
   var a: TLoc
-  d = initLoc(locExpr, n, OnUnknown)
+  initLoc(d, locExpr, n, OnUnknown)
 
   if n[0].kind == nkClosure:
-    a = initLocExpr(p, n[0][1])
+    initLocExpr(p, n[0][1], a)
     d.r = "(((NI*) $1)[1] < 0)" % [rdLoc(a)]
   else:
-    a = initLocExpr(p, n[0])
+    initLocExpr(p, n[0], a)
     # the environment is guaranteed to contain the 'state' field at offset 1:
     d.r = "((((NI*) $1.ClE_0)[1]) < 0)" % [rdLoc(a)]
 
@@ -340,7 +341,7 @@ 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):
-        loc = initLocExprSingleUse(p.module.preInitProc, vn)
+        initLocExprSingleUse(p.module.preInitProc, vn, loc)
       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)
@@ -361,7 +362,7 @@ proc genSingleVar(p: BProc, v: PSym; vn, value: PNode) =
         genCppVarForCtor(p, v, vn, value, decl)
         line(p, cpsStmts, decl)
       else:
-        tmp = initLocExprSingleUse(p, value)
+        initLocExprSingleUse(p, value, tmp)
         lineF(p, cpsStmts, "$# = $#;\n", [decl, tmp.rdLoc])
       return
     assignLocalVar(p, vn)
@@ -407,7 +408,8 @@ 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])
+  var v: TLoc
+  initLocExpr(p, a[0], v)
   genLineDir(p, a)
   if immediateAsgn:
     loadInto(p, a[0], a[2], v)
@@ -442,7 +444,7 @@ proc genIf(p: BProc, n: PNode, d: var TLoc) =
     a: TLoc
     lelse: TLabel
   if not isEmptyType(n.typ) and d.k == locNone:
-    d = getTemp(p, n.typ)
+    getTemp(p, n.typ, d)
   genLineDir(p, n)
   let lend = getLabel(p)
   for it in n.sons:
@@ -450,7 +452,7 @@ 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)
-      a = initLocExprSingleUse(p, it[0])
+      initLocExprSingleUse(p, it[0], a)
       lelse = getLabel(p)
       inc(p.labels)
       lineF(p, cpsStmts, "if (!$1) goto $2;$n",
@@ -518,7 +520,7 @@ 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 = 0
+  var arraySize: int
   for i in 0..<n.len:
     let it = n[i]
     if it.kind == nkCaseStmt:
@@ -552,7 +554,8 @@ proc genComputedGoto(p: BProc; n: PNode) =
     genStmts(p, n[j])
 
   let caseStmt = n[casePos]
-  var a: TLoc = initLocExpr(p, caseStmt[0])
+  var a: TLoc
+  initLocExpr(p, caseStmt[0], a)
   # first goto:
   lineF(p, cpsStmts, "goto *$#[$#];$n", [tmp, a.rdLoc])
 
@@ -590,7 +593,8 @@ proc genComputedGoto(p: BProc; n: PNode) =
       else:
         genStmts(p, it)
 
-    var a: TLoc = initLocExpr(p, caseStmt[0])
+    var a: TLoc
+    initLocExpr(p, caseStmt[0], a)
     lineF(p, cpsStmts, "goto *$#[$#];$n", [tmp, a.rdLoc])
     endBlock(p)
 
@@ -618,7 +622,7 @@ proc genWhileStmt(p: BProc, t: PNode) =
     else:
       p.breakIdx = startBlock(p, "while (1) {$n")
       p.blocks[p.breakIdx].isLoop = true
-      a = initLocExpr(p, t[0])
+      initLocExpr(p, t[0], a)
       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))
@@ -637,7 +641,7 @@ 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:
-      d = getTemp(p, n.typ)
+      getTemp(p, n.typ, d)
     d.flags.incl(lfEnforceDeref)
   preserveBreakIdx:
     p.breakIdx = startBlock(p)
@@ -657,13 +661,14 @@ 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)
-    var rangeA = initLocExpr(p, call[1])
-    var rangeB = initLocExpr(p, call[2])
+    initLocExpr(p, call[1], rangeA)
+    initLocExpr(p, call[2], rangeB)
 
     # $n at the beginning because of #9710
     if call.len == 4: # procName(a, b, annotation)
@@ -680,7 +685,8 @@ proc genParForStmt(p: BProc, t: PNode) =
                     rangeA.rdLoc, rangeB.rdLoc,
                     call[3].getStr.rope])
     else: # `||`(a, b, step, annotation)
-      var step: TLoc = initLocExpr(p, call[3])
+      var step: TLoc
+      initLocExpr(p, call[3], step)
       lineF(p, cpsStmts, "$n#pragma omp $5$n" &
                     "for ($1 = $2; $1 <= $3; $1 += $4)",
                     [forLoopVar.loc.rdLoc,
@@ -750,7 +756,8 @@ 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])
+    var a: TLoc
+    initLocExprSingleUse(p, t[0], a)
     finallyActions(p)
     var e = rdLoc(a)
     discard getTypeDesc(p.module, t[0].typ)
@@ -780,12 +787,12 @@ template genCaseGenericBranch(p: BProc, b: PNode, e: TLoc,
   var x, y: TLoc
   for i in 0..<b.len - 1:
     if b[i].kind == nkRange:
-      x = initLocExpr(p, b[i][0])
-      y = initLocExpr(p, b[i][1])
+      initLocExpr(p, b[i][0], x)
+      initLocExpr(p, b[i][1], y)
       lineCg(p, cpsStmts, rangeFormat,
            [rdCharLoc(e), rdCharLoc(x), rdCharLoc(y), labl])
     else:
-      x = initLocExpr(p, b[i])
+      initLocExpr(p, b[i], x)
       lineCg(p, cpsStmts, eqFormat, [rdCharLoc(e), rdCharLoc(x), labl])
 
 proc genCaseSecondPass(p: BProc, t: PNode, d: var TLoc,
@@ -827,7 +834,8 @@ 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])
+  var a: TLoc
+  initLocExpr(p, t[0], a)
   var lend = genIfForCaseUntil(p, t, d, rangeFormat, eqFormat, t.len-1, a)
   fixLabel(p, lend)
 
@@ -837,8 +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)
-    x = initLocExpr(p, b[i])
-    var j: int = 0
+    initLocExpr(p, b[i], x)
+    var j: int
     case b[i].kind
     of nkStrLit..nkTripleStrLit:
       j = int(hashString(p.config, b[i].strVal) and high(branches))
@@ -861,7 +869,8 @@ 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]) # first pass: generate ifs+goto:
+    var a: TLoc
+    initLocExpr(p, t[0], a) # fist pass: generate ifs+goto:
     var labId = p.labels
     for i in 1..<t.len:
       inc(p.labels)
@@ -897,7 +906,6 @@ 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
@@ -905,7 +913,6 @@ 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)
@@ -941,7 +948,8 @@ 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])
+  var a: TLoc
+  initLocExpr(p, n[0], a)
   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",
@@ -963,15 +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:
-    d = getTemp(p, t.typ)
+    getTemp(p, t.typ, d)
   case skipTypes(t[0].typ, abstractVarRange).kind
   of tyString:
     genStringCase(p, t, tyString, d)
@@ -1022,7 +1033,7 @@ proc genTryCpp(p: BProc, t: PNode, d: var TLoc) =
   p.module.includeHeader("<exception>")
 
   if not isEmptyType(t.typ) and d.k == locNone:
-    d = getTemp(p, t.typ)
+    getTemp(p, t.typ, d)
   genLineDir(p, t)
 
   inc(p.labels, 2)
@@ -1187,7 +1198,7 @@ proc genTryCppOld(p: BProc, t: PNode, d: var TLoc) =
     expr(p, body, d)
 
   if not isEmptyType(t.typ) and d.k == locNone:
-    d = getTemp(p, t.typ)
+    getTemp(p, t.typ, d)
   genLineDir(p, t)
   cgsym(p.module, "popCurrentExceptionEx")
   let fin = if t[^1].kind == nkFinally: t[^1] else: nil
@@ -1265,7 +1276,7 @@ proc genTryGoto(p: BProc; t: PNode; d: var TLoc) =
   p.flags.incl nimErrorFlagAccessed
 
   if not isEmptyType(t.typ) and d.k == locNone:
-    d = getTemp(p, t.typ)
+    getTemp(p, t.typ, d)
 
   expr(p, t[0], d)
 
@@ -1372,7 +1383,7 @@ proc genTrySetjmp(p: BProc, t: PNode, d: var TLoc) =
   #    propagateCurrentException();
   #
   if not isEmptyType(t.typ) and d.k == locNone:
-    d = getTemp(p, t.typ)
+    getTemp(p, t.typ, d)
   let quirkyExceptions = p.config.exc == excQuirky or
       (t.kind == nkHiddenTryStmt and sfSystemModule in p.module.module.flags)
   if not quirkyExceptions:
@@ -1381,7 +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])
@@ -1484,7 +1495,8 @@ 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)
+        var a: TLoc
+        initLocExpr(p, it, a)
         res.add($rdLoc(a))
       elif sym.kind == skType:
         res.add($getTypeDesc(p.module, sym.typ))
@@ -1496,7 +1508,8 @@ proc genAsmOrEmitStmt(p: BProc, t: PNode, isAsmStmt=false; result: var Rope) =
       res.add($getTypeDesc(p.module, it.typ))
     else:
       discard getTypeDesc(p.module, skipTypes(it.typ, abstractPtrs))
-      var a: TLoc = initLocExpr(p, it)
+      var a: TLoc
+      initLocExpr(p, it, a)
       res.add($a.rdLoc)
 
   if isAsmStmt and hasGnuAsm in CC[p.config.cCompiler].props:
@@ -1598,10 +1611,11 @@ 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]
-  var a = initLocExpr(p, e[0])
-  var tmp: TLoc = getTemp(p, a.t)
+  initLocExpr(p, e[0], a)
+  getTemp(p, a.t, tmp)
   expr(p, e[1], tmp)
   if p.inUncheckedAssignSection == 0:
     let field = dotExpr[1].sym
@@ -1619,8 +1633,9 @@ proc genAsgn(p: BProc, e: PNode, fastAsgn: bool) =
   else:
     let le = e[0]
     let ri = e[1]
-    var a: TLoc = initLoc(locNone, le, OnUnknown)
+    var a: TLoc
     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
@@ -1632,7 +1647,7 @@ proc genAsgn(p: BProc, e: PNode, fastAsgn: bool) =
     loadInto(p, le, ri, a)
 
 proc genStmts(p: BProc, t: PNode) =
-  var a: TLoc = default(TLoc)
+  var a: 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, needsInit=false): TLoc
+proc getTemp(p: BProc, t: PType, result: var TLoc; needsInit=false)
 
 proc genTraverseProc(c: TTraversalClosure, accessor: Rope, n: PNode;
                      typ: PType) =
@@ -74,7 +74,8 @@ 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))
+    var i: TLoc
+    getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt), i)
     var oldCode = p.s(cpsStmts)
     freeze oldCode
     linefmt(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
@@ -118,10 +119,12 @@ 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))
+  var i: TLoc
+  getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt), i)
   var oldCode = p.s(cpsStmts)
   freeze oldCode
-  var a: TLoc = TLoc(r: accessor)
+  var a: TLoc
+  a.r = accessor
 
   lineF(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
       [i.r, lenExpr(c.p, a)])

compiler/ccgtypes.nim

@@ -54,13 +54,31 @@ proc mangleField(m: BModule; name: PIdent): string =
   if isKeyword(name):
     result.add "_0"
 
+proc mangleProc(m: BModule; s: PSym; makeUnique: bool): string = 
+  result = "_Z"  # Common prefix in Itanium ABI
+  result.add encodeSym(m, s, makeUnique)
+  if s.typ.len > 1: #we dont care about the return param
+    for i in 1..<s.typ.len: 
+      if s.typ[i].isNil: continue
+      result.add encodeType(m, s.typ[i])
+  
+  if result in m.g.mangledPrcs:
+    result = mangleProc(m, s, true)
+  else:
+    m.g.mangledPrcs.incl(result)
+
 proc fillBackendName(m: BModule; s: PSym) =
   if s.loc.r == "":
-    var result = s.name.s.mangle.rope
-    result.add "__"
-    result.add m.g.graph.ifaces[s.itemId.module].uniqueName
-    result.add "_u"
-    result.addInt s.itemId.item # s.disamb #
+    var result: Rope
+    if not m.compileToCpp and s.kind in routineKinds and optCDebug in m.g.config.globalOptions and
+      m.g.config.symbolFiles == disabledSf: 
+      result = mangleProc(m, s, false).rope
+    else:
+      result = s.name.s.mangle.rope
+      result.add "__"
+      result.add m.g.graph.ifaces[s.itemId.module].uniqueName
+      result.add "_u"
+      result.addInt s.itemId.item # s.disamb #
     if m.hcrOn:
       result.add '_'
       result.add(idOrSig(s, m.module.name.s.mangle, m.sigConflicts, m.config))
@@ -206,12 +224,8 @@ 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:
-      result = ctVoid
-      doAssert(false, "mapType: " & $typ.kind)
-  else:
-    result = ctVoid
-    doAssert(false, "mapType: " & $typ.kind)
+    else: doAssert(false, "mapType: " & $typ.kind)
+  else: doAssert(false, "mapType: " & $typ.kind)
 
 
 proc mapReturnType(conf: ConfigRef; typ: PType): TCTypeKind =
@@ -256,9 +270,15 @@ proc isInvalidReturnType(conf: ConfigRef; typ: PType, isProc = true): bool =
           {tyVar, tyLent, tyRef, tyPtr})
     of ctStruct:
       let t = skipTypes(rettype, typedescInst)
-      if rettype.isImportedCppType or t.isImportedCppType: return false
-      result = containsGarbageCollectedRef(t) or
-          (t.kind == tyObject and not isObjLackingTypeField(t))
+      if rettype.isImportedCppType or t.isImportedCppType or
+          (typ.callConv == ccCDecl and conf.selectedGC in {gcArc, gcAtomicArc, gcOrc}):
+        # prevents nrvo for cdecl procs; # bug #23401
+        result = false
+      else:
+        result = containsGarbageCollectedRef(t) or
+            (t.kind == tyObject and not isObjLackingTypeField(t)) or
+            (getSize(conf, rettype) == szUnknownSize and (t.sym == nil or sfImportc notin t.sym.flags))
+
     else: result = false
 
 const
@@ -326,9 +346,7 @@ 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:
-      result = ""
-      internalError(m.config, "tyStatic for getSimpleTypeDesc")
+    else: internalError(m.config, "tyStatic for getSimpleTypeDesc")
   of tyGenericInst, tyAlias, tySink, tyOwned:
     result = getSimpleTypeDesc(m, lastSon typ)
   else: result = ""
@@ -477,11 +495,11 @@ 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:
-            raiseAssert "invalid format string: " & frmt
+            doAssert false, "invalid format string: " & frmt
           else:
             res.add(arg[j-1])
         else:
-          raiseAssert "invalid format string: " & frmt
+          doAssert false, "invalid format string: " & frmt
       var start = i
       while i < frmt.len:
         if frmt[i] != c: inc(i)
@@ -493,12 +511,12 @@ 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, name, params: var string,
+proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, params: var string,
                    check: var IntSet, declareEnvironment=true;
                    weakDep=false;) =
   let t = prc.typ
   let isCtor = sfConstructor in prc.flags
-  if isCtor or (name[0] == '~' and sfMember in prc.flags): #destructors cant have void
+  if isCtor:
     rettype = ""
   elif t[0] == nil or isInvalidReturnType(m.config, t):
     rettype = "void"
@@ -507,8 +525,8 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, name, params
       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],
@@ -555,7 +573,6 @@ proc genMemberProcParams(m: BModule; prc: PSym, superCall, rettype, name, params
 
   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)"
@@ -649,6 +666,13 @@ 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 genRecordFieldsAux(m: BModule; n: PNode,
                         rectype: PType,
                         check: var IntSet; result: var Rope; unionPrefix = "") =
@@ -713,7 +737,7 @@ proc genRecordFieldsAux(m: BModule; n: PNode,
       else:
         # don't use fieldType here because we need the
         # tyGenericInst for C++ template support
-        if fieldType.isOrHasImportedCppType():
+        if fieldType.isOrHasImportedCppType() or hasCppCtor(m, field.owner.typ):
           result.addf("\t$1$3 $2{};$n", [getTypeDescAux(m, field.loc.t, check, dkField), sname, noAlias])
         else:
           result.addf("\t$1$3 $2;$n", [getTypeDescAux(m, field.loc.t, check, dkField), sname, noAlias])
@@ -726,9 +750,9 @@ 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 = false
+    var isDefaultCtorGen, isCtorGen: bool
     for prc in procs:
-      var header: Rope = ""
+      var header: Rope
       if sfConstructor in prc.flags:
         isCtorGen = true
         if prc.typ.n.len == 1:
@@ -748,8 +772,7 @@ proc fillObjectFields*(m: BModule; typ: PType) =
 proc mangleDynLibProc(sym: PSym): Rope
   
 proc getRecordDescAux(m: BModule; typ: PType, name, baseType: Rope,
-                   check: var IntSet, hasField:var bool): Rope =
-  result = ""
+                   check: var IntSet, hasField:var bool): Rope =                 
   if typ.kind == tyObject:
     if typ[0] == nil:
       if lacksMTypeField(typ):
@@ -790,7 +813,7 @@ proc getRecordDesc(m: BModule; typ: PType, name: Rope,
         structOrUnion = "#pragma pack(push, 1)\L" & structOrUnion(typ)
   else:
     structOrUnion = structOrUnion(typ)
-  var baseType: string = ""
+  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:
@@ -847,7 +870,7 @@ 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:
-    raiseAssert "invalid apostrophe type parameter index"
+    doAssert false, "invalid apostrophe type parameter index"
 
   result = typ[idx]
   for i in 1..stars:
@@ -881,7 +904,6 @@ 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)
@@ -962,7 +984,7 @@ 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!
@@ -1039,7 +1061,7 @@ 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 = 0
+          var idx, stars: int
           if scanCppGenericSlot(cppName, i, idx, stars):
             result.add cppName.substr(chunkStart, chunkEnd)
             chunkStart = i
@@ -1119,7 +1141,7 @@ 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:
@@ -1149,19 +1171,11 @@ proc isReloadable(m: BModule; prc: PSym): bool =
 proc isNonReloadable(m: BModule; prc: PSym): bool =
   return m.hcrOn and sfNonReloadable in prc.flags
 
-proc parseVFunctionDecl(val: string; name, params, retType, superCall: var string; isFnConst, isOverride, isMemberVirtual: var bool; isCtor: bool, isFunctor=false) =
-  var afterParams: string = ""
+proc parseVFunctionDecl(val: string; name, params, retType, superCall: var string; isFnConst, isOverride: var bool; isCtor: bool) =
+  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:
@@ -1170,28 +1184,28 @@ 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 sfCppMember * prc.flags != {}
+  assert {sfVirtual, sfConstructor} * 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[0]
+    typ = prc.typ.sons[0]
   else:
-    typ = prc.typ[1]
+    typ = prc.typ.sons[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, 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 = ""
+  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
   if isCtor:
     name = typDesc
   if isFnConst:
@@ -1203,7 +1217,7 @@ proc genMemberProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool =
         override = " override"
     superCall = ""
   else:
-    if not isCtor:
+    if isVirtual:
       prc.loc.r = "$1$2(@)" % [memberOp, name]
     elif superCall != "":
       superCall = " : " & superCall
@@ -1220,7 +1234,7 @@ proc genProcHeader(m: BModule; prc: PSym; result: var Rope; asPtr: bool = false)
   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
@@ -1421,7 +1435,7 @@ proc genObjectInfo(m: BModule; typ, origType: PType, name: Rope; info: TLineInfo
   else:
     genTypeInfoAuxBase(m, typ, origType, name, rope("0"), info)
   var tmp = getNimNode(m)
-  if not isImportedType(typ):
+  if (not isImportedType(typ)) or tfCompleteStruct in typ.flags:
     genObjectFields(m, typ, origType, typ.n, tmp, info)
   m.s[cfsTypeInit3].addf("$1.node = &$2;$n", [tiNameForHcr(m, name), tmp])
   var t = typ[0]
@@ -1460,7 +1474,7 @@ 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:
@@ -1539,7 +1553,6 @@ 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 & "."
@@ -1772,7 +1785,7 @@ 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 or m.hcrOn:
+  if m.compileToCpp:
     genTypeInfoV2OldImpl(m, t, origType, result, info)
   else:
     genTypeInfoV2Impl(m, t, origType, result, info)
@@ -1927,8 +1940,11 @@ proc genTypeSection(m: BModule, n: PNode) =
     if len(n[i]) == 0: continue
     if n[i][0].kind != nkPragmaExpr: continue
     for p in 0..<n[i][0].len:
-      if (n[i][0][p].kind != nkSym): continue
-      if sfExportc in n[i][0][p].sym.flags:        
-        discard getTypeDescAux(m, n[i][0][p].typ, intSet, descKindFromSymKind(n[i][0][p].sym.kind))
+      if (n[i][0][p].kind notin {nkSym, nkPostfix}): continue
+      var s = n[i][0][p]
+      if s.kind == nkPostfix:
+        s = n[i][0][p][1]
+      if {sfExportc, sfCompilerProc} * s.sym.flags == {sfExportc}:
+        discard getTypeDescAux(m, s.typ, intSet, descKindFromSymKind(s.sym.kind))
         if m.g.generatedHeader != nil:
-          discard getTypeDescAux(m.g.generatedHeader, n[i][0][p].typ, intSet, descKindFromSymKind(n[i][0][p].sym.kind))
+          discard getTypeDescAux(m.g.generatedHeader, s.typ, intSet, descKindFromSymKind(s.sym.kind))

compiler/ccgutils.nim

@@ -13,22 +13,21 @@ import
   ast, types, hashes, strutils, msgs, wordrecg,
   platform, trees, options, cgendata
 
+import std/[hashes, strutils, formatfloat]
+
 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:
-    result = nil
+  else: discard
 
 proc stmtsContainPragma*(n: PNode, w: TSpecialWord): bool =
   result = getPragmaStmt(n, w) != nil
@@ -124,10 +123,10 @@ proc mapSetType(conf: ConfigRef; typ: PType): TCTypeKind =
 proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
   var pt = skipTypes(s.typ, typedescInst)
   assert skResult != s.kind
-  
+
   #note precedence: params override types
   if optByRef in s.options: return true
-  elif sfByCopy in s.flags: return false 
+  elif sfByCopy in s.flags: return false
   elif tfByRef in pt.flags: return true
   elif tfByCopy in pt.flags: return false
   case pt.kind
@@ -135,6 +134,9 @@ proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
     if s.typ.sym != nil and sfForward in s.typ.sym.flags:
       # forwarded objects are *always* passed by pointers for consistency!
       result = true
+    elif s.typ.kind == tySink and conf.selectedGC notin {gcArc, gcAtomicArc, gcOrc, gcHooks}:
+      # bug #23354:
+      result = false
     elif (optByRef in s.options) or (getSize(conf, pt) > conf.target.floatSize * 3):
       result = true           # requested anyway
     elif (tfFinal in pt.flags) and (pt[0] == nil):
@@ -151,3 +153,64 @@ proc ccgIntroducedPtr*(conf: ConfigRef; s: PSym, retType: PType): bool =
     result = not (pt.kind in {tyVar, tyArray, tyOpenArray, tyVarargs, tyRef, tyPtr, tyPointer} or
       pt.kind == tySet and mapSetType(conf, pt) == ctArray)
 
+proc encodeName*(name: string): string =
+  result = mangle(name)
+  result = $result.len & result
+
+proc makeUnique(m: BModule; s: PSym, name: string = ""): string =
+  result = if name == "": s.name.s else: name
+  result.add "__"
+  result.add m.g.graph.ifaces[s.itemId.module].uniqueName
+  result.add "_u"
+  result.add $s.itemId.item
+
+proc encodeSym*(m: BModule; s: PSym; makeUnique: bool = false): string =
+  #Module::Type
+  var name = s.name.s
+  if makeUnique:
+    name = makeUnique(m, s, name)
+  "N" & encodeName(s.skipGenericOwner.name.s) & encodeName(name) & "E"
+
+proc elementType*(n: PType): PType {.inline.} = n.sons[^1]
+
+proc encodeType*(m: BModule; t: PType): string =
+  result = ""
+  var kindName = ($t.kind)[2..^1]
+  kindName[0] = toLower($kindName[0])[0]
+  case t.kind
+  of tyObject, tyEnum, tyDistinct, tyUserTypeClass, tyGenericParam:
+    result = encodeSym(m, t.sym)
+  of tyGenericInst, tyUserTypeClassInst, tyGenericBody:
+    result = encodeName(t[0].sym.name.s)
+    result.add "I"
+    for i in 1..<t.len - 1:
+      result.add encodeType(m, t[i])
+    result.add "E"
+  of tySequence, tyOpenArray, tyArray, tyVarargs, tyTuple, tyProc, tySet, tyTypeDesc,
+    tyPtr, tyRef, tyVar, tyLent, tySink, tyStatic, tyUncheckedArray, tyOr, tyAnd, tyBuiltInTypeClass:
+    result =
+      case t.kind:
+      of tySequence: encodeName("seq")
+      else: encodeName(kindName)
+    result.add "I"
+    for i in 0..<t.len:
+      let s = t[i]
+      if s.isNil: continue
+      result.add encodeType(m, s)
+    result.add "E"
+  of tyRange:
+    var val = "range_"
+    if t.n[0].typ.kind in {tyFloat..tyFloat128}:
+      val.addFloat t.n[0].floatVal
+      val.add "_"
+      val.addFloat t.n[1].floatVal
+    else:
+      val.add $t.n[0].intVal & "_" & $t.n[1].intVal
+    result = encodeName(val)
+  of tyString..tyUInt64, tyPointer, tyBool, tyChar, tyVoid, tyAnything, tyNil, tyEmpty:
+    result = encodeName(kindName)
+  of tyAlias, tyInferred, tyOwned:
+    result = encodeType(m, t.elementType)
+  else:
+    assert false, "encodeType " & $t.kind
+

compiler/cgen.nim

@@ -30,6 +30,12 @@ import strutils except `%`, addf # collides with ropes.`%`
 from ic / ic import ModuleBackendFlag
 import dynlib
 
+const
+  # we use some ASCII control characters to insert directives that will be converted to real code in a postprocessing pass
+  postprocessDirStart = '\1'
+  postprocessDirSep = '\31'
+  postprocessDirEnd = '\23'
+
 when not declared(dynlib.libCandidates):
   proc libCandidates(s: string, dest: var seq[string]) =
     ## given a library name pattern `s` write possible library names to `dest`.
@@ -61,10 +67,12 @@ proc findPendingModule(m: BModule, s: PSym): BModule =
     var ms = getModule(s)
     result = m.g.modules[ms.position]
 
-proc initLoc(k: TLocKind, lode: PNode, s: TStorageLoc, flags: TLocFlags = {}): TLoc =
-  result = TLoc(k: k, storage: s, lode: lode,
-               r: "", flags: flags
-  )
+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 fillLoc(a: var TLoc, k: TLocKind, lode: PNode, r: Rope, s: TStorageLoc) {.inline.} =
   # fills the loc if it is not already initialized
@@ -264,24 +272,28 @@ proc safeLineNm(info: TLineInfo): int =
   result = toLinenumber(info)
   if result < 0: result = 0 # negative numbers are not allowed in #line
 
-proc genCLineDir(r: var Rope, filename: string, line: int; conf: ConfigRef) =
+proc genPostprocessDir(field1, field2, field3: string): string =
+  result = postprocessDirStart & field1 & postprocessDirSep & field2 & postprocessDirSep & field3 & postprocessDirEnd
+
+proc genCLineDir(r: var Rope, fileIdx: FileIndex, line: int; conf: ConfigRef) =
   assert line >= 0
   if optLineDir in conf.options and line > 0:
-    r.addf("\n#line $2 $1\n",
-        [rope(makeSingleLineCString(filename)), rope(line)])
+    if fileIdx == InvalidFileIdx:
+      r.add(rope("\n#line " & $line & " \"generated_not_to_break_here\"\n"))
+    else:
+      r.add(rope("\n#line " & $line & " FX_" & $fileIdx.int32 & "\n"))
 
-proc genCLineDir(r: var Rope, filename: string, line: int; p: BProc; info: TLineInfo; lastFileIndex: FileIndex) =
+proc genCLineDir(r: var Rope, fileIdx: FileIndex, line: int; p: BProc; info: TLineInfo; lastFileIndex: FileIndex) =
   assert line >= 0
   if optLineDir in p.config.options and line > 0:
-    if lastFileIndex == info.fileIndex:
-        r.addf("\n#line $1\n", [rope(line)])
+    if fileIdx == InvalidFileIdx:
+      r.add(rope("\n#line " & $line & " \"generated_not_to_break_here\"\n"))
     else:
-      r.addf("\n#line $2 $1\n",
-        [rope(makeSingleLineCString(filename)), rope(line)])
+      r.add(rope("\n#line " & $line & " FX_" & $fileIdx.int32 & "\n"))
 
 proc genCLineDir(r: var Rope, info: TLineInfo; conf: ConfigRef) =
   if optLineDir in conf.options:
-    genCLineDir(r, toFullPath(conf, info), info.safeLineNm, conf)
+    genCLineDir(r, info.fileIndex, info.safeLineNm, conf)
 
 proc freshLineInfo(p: BProc; info: TLineInfo): bool =
   if p.lastLineInfo.line != info.line or
@@ -289,17 +301,14 @@ proc freshLineInfo(p: BProc; info: TLineInfo): bool =
     p.lastLineInfo.line = info.line
     p.lastLineInfo.fileIndex = info.fileIndex
     result = true
-  else:
-    result = false
 
 proc genCLineDir(r: var Rope, p: BProc, info: TLineInfo; conf: ConfigRef) =
   if optLineDir in conf.options:
     let lastFileIndex = p.lastLineInfo.fileIndex
     if freshLineInfo(p, info):
-      genCLineDir(r, toFullPath(conf, info), info.safeLineNm, p, info, lastFileIndex)
+      genCLineDir(r, info.fileIndex, 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:
@@ -307,16 +316,11 @@ proc genLineDir(p: BProc, t: PNode) =
   let lastFileIndex = p.lastLineInfo.fileIndex
   let freshLine = freshLineInfo(p, t.info)
   if freshLine:
-    genCLineDir(p.s(cpsStmts), toFullPath(p.config, t.info), line, p, t.info, lastFileIndex)
+    genCLineDir(p.s(cpsStmts), t.info.fileIndex, line, p, t.info, lastFileIndex)
   if ({optLineTrace, optStackTrace} * p.options == {optLineTrace, optStackTrace}) and
       (p.prc == nil or sfPure notin p.prc.flags) and t.info.fileIndex != InvalidFileIdx:
       if freshLine:
-        if lastFileIndex == t.info.fileIndex:
-          linefmt(p, cpsStmts, "nimln_($1);",
-              [line])
-        else:
-          linefmt(p, cpsStmts, "nimlf_($1, $2);",
-              [line, quotedFilename(p.config, t.info)])
+        line(p, cpsStmts, genPostprocessDir("nimln", $line, $t.info.fileIndex.int32))
 
 proc accessThreadLocalVar(p: BProc, s: PSym)
 proc emulatedThreadVars(conf: ConfigRef): bool {.inline.}
@@ -402,6 +406,8 @@ proc rdCharLoc(a: TLoc): Rope =
 type
   TAssignmentFlag = enum
     needToCopy
+    needToCopySinkParam
+    needTempForOpenArray
   TAssignmentFlags = set[TAssignmentFlag]
 
 proc genObjConstr(p: BProc, e: PNode, d: var TLoc)
@@ -433,7 +439,7 @@ 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 = default(TLoc)
+      var tmp: TLoc
       if mode == constructRefObj:
         let objType = t.skipTypes(abstractInst+{tyRef})
         rawConstExpr(p, newNodeIT(nkType, a.lode.info, objType), tmp)
@@ -481,7 +487,8 @@ proc resetLoc(p: BProc, loc: var TLoc) =
       linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
   elif not isComplexValueType(typ):
     if containsGcRef:
-      var nilLoc: TLoc = initLoc(locTemp, loc.lode, OnStack)
+      var nilLoc: TLoc
+      initLoc(nilLoc, locTemp, loc.lode, OnStack)
       nilLoc.r = rope("NIM_NIL")
       genRefAssign(p, loc, nilLoc)
     else:
@@ -511,7 +518,8 @@ proc constructLoc(p: BProc, loc: var TLoc, isTemp = false) =
     linefmt(p, cpsStmts, "$1.len = 0; $1.p = NIM_NIL;$n", [rdLoc(loc)])
   elif not isComplexValueType(typ):
     if containsGarbageCollectedRef(loc.t):
-      var nilLoc: TLoc = initLoc(locTemp, loc.lode, OnStack)
+      var nilLoc: TLoc
+      initLoc(nilLoc, locTemp, loc.lode, OnStack)
       nilLoc.r = rope("NIM_NIL")
       genRefAssign(p, loc, nilLoc)
     else:
@@ -538,14 +546,17 @@ proc initLocalVar(p: BProc, v: PSym, immediateAsgn: bool) =
     if not immediateAsgn:
       constructLoc(p, v.loc)
 
-proc getTemp(p: BProc, t: PType, needsInit=false): TLoc =
+proc getTemp(p: BProc, t: PType, result: var TLoc; needsInit=false) =
   inc(p.labels)
-  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp, lode: lodeTyp t,
-                storage: OnStack, flags: {})
+  result.r = "T" & rope(p.labels) & "_"
   if p.module.compileToCpp and isOrHasImportedCppType(t):
     linefmt(p, cpsLocals, "$1 $2{};$n", [getTypeDesc(p.module, t, dkVar), result.r])
   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.
@@ -556,21 +567,25 @@ proc getTemp(p: BProc, t: PType, needsInit=false): TLoc =
         echo "ENORMOUS TEMPORARY! ", p.config $ p.lastLineInfo
       writeStackTrace()
 
-proc getTempCpp(p: BProc, t: PType, value: Rope): TLoc =
+proc getTempCpp(p: BProc, t: PType, result: var TLoc; value: Rope) =
   inc(p.labels)
-  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp, lode: lodeTyp t,
-                storage: OnStack, flags: {})
+  result.r = "T" & rope(p.labels) & "_"
   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): TLoc =
+proc getIntTemp(p: BProc, result: var TLoc) =
   inc(p.labels)
-  result = TLoc(r: "T" & rope(p.labels) & "_", k: locTemp,
-                storage: OnStack, lode: lodeTyp getSysType(p.module.g.graph, unknownLineInfo, tyInt),
-                flags: {})
+  result.r = "T" & rope(p.labels) & "_"
   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)
@@ -638,7 +653,7 @@ 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
@@ -727,12 +742,12 @@ proc genLiteral(p: BProc, n: PNode; result: var Rope)
 proc genOtherArg(p: BProc; ri: PNode; i: int; typ: PType; result: var Rope; argsCounter: var int)
 proc raiseExit(p: BProc)
 
-proc initLocExpr(p: BProc, e: PNode, flags: TLocFlags = {}): TLoc =
-  result = initLoc(locNone, e, OnUnknown, flags)
+proc initLocExpr(p: BProc, e: PNode, result: var TLoc, flags: TLocFlags = {}) =
+  initLoc(result, locNone, e, OnUnknown, flags)
   expr(p, e, result)
 
-proc initLocExprSingleUse(p: BProc, e: PNode): TLoc =
-  result = initLoc(locNone, e, OnUnknown)
+proc initLocExprSingleUse(p: BProc, e: PNode, result: var TLoc) =
+  initLoc(result, 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"
@@ -823,7 +838,8 @@ proc loadDynamicLib(m: BModule, lib: PLib) =
       var p = newProc(nil, m)
       p.options.excl optStackTrace
       p.flags.incl nimErrorFlagDisabled
-      var dest: TLoc = initLoc(locTemp, lib.path, OnStack)
+      var dest: TLoc
+      initLoc(dest, locTemp, lib.path, OnStack)
       dest.r = getTempName(m)
       appcg(m, m.s[cfsDynLibInit],"$1 $2;$n",
            [getTypeDesc(m, lib.path.typ, dkVar), rdLoc(dest)])
@@ -858,10 +874,11 @@ proc symInDynamicLib(m: BModule, sym: PSym) =
   inc(m.labels, 2)
   if isCall:
     let n = lib.path
-    var a: TLoc = initLocExpr(m.initProc, n[0])
+    var a: TLoc
+    initLocExpr(m.initProc, n[0], a)
     var params = rdLoc(a) & "("
     for i in 1..<n.len-1:
-      a = initLocExpr(m.initProc, n[i])
+      initLocExpr(m.initProc, n[i], a)
       params.add(rdLoc(a))
       params.add(", ")
     let load = "\t$1 = ($2) ($3$4));$n" %
@@ -976,11 +993,19 @@ 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
@@ -988,12 +1013,7 @@ 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
@@ -1012,7 +1032,7 @@ proc easyResultAsgn(n: PNode): PNode =
 type
   InitResultEnum = enum Unknown, InitSkippable, InitRequired
 
-proc allPathsAsgnResult(n: PNode): InitResultEnum =
+proc allPathsAsgnResult(p: BProc; n: PNode): InitResultEnum =
   # Exceptions coming from calls don't have not be considered here:
   #
   # proc bar(): string = raise newException(...)
@@ -1027,7 +1047,7 @@ proc allPathsAsgnResult(n: PNode): InitResultEnum =
   #   echo "a was not written to"
   #
   template allPathsInBranch(it) =
-    let a = allPathsAsgnResult(it)
+    let a = allPathsAsgnResult(p, it)
     case a
     of InitRequired: return InitRequired
     of InitSkippable: discard
@@ -1039,7 +1059,7 @@ proc allPathsAsgnResult(n: PNode): InitResultEnum =
   case n.kind
   of nkStmtList, nkStmtListExpr:
     for it in n:
-      result = allPathsAsgnResult(it)
+      result = allPathsAsgnResult(p, it)
       if result != Unknown: return result
   of nkAsgn, nkFastAsgn, nkSinkAsgn:
     if n[0].kind == nkSym and n[0].sym.kind == skResult:
@@ -1047,6 +1067,8 @@ proc allPathsAsgnResult(n: PNode): InitResultEnum =
       else: result = InitRequired
     elif containsResult(n):
       result = InitRequired
+    else:
+      result = allPathsAsgnResult(p, n[1])
   of nkReturnStmt:
     if n.len > 0:
       if n[0].kind == nkEmpty and result != InitSkippable:
@@ -1055,7 +1077,7 @@ proc allPathsAsgnResult(n: PNode): InitResultEnum =
         # initialized. This avoids cases like #9286 where this heuristic lead to
         # wrong code being generated.
         result = InitRequired
-      else: result = allPathsAsgnResult(n[0])
+      else: result = allPathsAsgnResult(p, n[0])
   of nkIfStmt, nkIfExpr:
     var exhaustive = false
     result = InitSkippable
@@ -1081,9 +1103,9 @@ proc allPathsAsgnResult(n: PNode): InitResultEnum =
   of nkWhileStmt:
     # some dubious code can assign the result in the 'while'
     # condition and that would be fine. Everything else isn't:
-    result = allPathsAsgnResult(n[0])
+    result = allPathsAsgnResult(p, n[0])
     if result == Unknown:
-      result = allPathsAsgnResult(n[1])
+      result = allPathsAsgnResult(p, n[1])
       # we cannot assume that the 'while' loop is really executed at least once:
       if result == InitSkippable: result = Unknown
   of harmless:
@@ -1108,9 +1130,17 @@ proc allPathsAsgnResult(n: PNode): InitResultEnum =
     allPathsInBranch(n[0])
     for i in 1..<n.len:
       if n[i].kind == nkFinally:
-        result = allPathsAsgnResult(n[i].lastSon)
+        result = allPathsAsgnResult(p, n[i].lastSon)
       else:
         allPathsInBranch(n[i].lastSon)
+  of nkCallKinds:
+    if canRaiseDisp(p, n[0]):
+      result = InitRequired
+    else:
+      for i in 0..<n.safeLen:
+        allPathsInBranch(n[i])
+  of nkRaiseStmt:
+    result = InitRequired
   else:
     for i in 0..<n.safeLen:
       allPathsInBranch(n[i])
@@ -1118,7 +1148,7 @@ 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]
@@ -1136,8 +1166,7 @@ proc isNoReturn(m: BModule; s: PSym): bool {.inline.} =
 proc genProcAux*(m: BModule, prc: PSym) =
   var p = newProc(prc, m)
   var header = newRopeAppender()
-  let isCppMember = m.config.backend == backendCpp and sfCppMember * prc.flags != {}
-  if isCppMember:
+  if m.config.backend == backendCpp and {sfVirtual, sfConstructor} * prc.flags != {}:
     genMemberProcHeader(m, prc, header)
   else:
     genProcHeader(m, prc, header)
@@ -1160,13 +1189,20 @@ 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)
+        var a: TLoc
+        initLocExprSingleUse(p, val, a)
         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(p, procBody) == InitSkippable:
+          # In an ideal world the codegen could rely on injectdestructors doing its job properly
+          # and then the analysis step would not be required.
+          discard "result init optimized out"
+        else:
+          initLocalVar(p, res, immediateAsgn=false)
       returnStmt = ropecg(p.module, "\treturn $1;$n", [rdLoc(res.loc)])
     elif sfConstructor in prc.flags:
       fillLoc(resNode.sym.loc, locParam, resNode, "this", OnHeap)
@@ -1180,7 +1216,7 @@ proc genProcAux*(m: BModule, prc: PSym) =
       # global is either 'nil' or points to valid memory and so the RC operation
       # succeeds without touching not-initialized memory.
       if sfNoInit in prc.flags: discard
-      elif allPathsAsgnResult(procBody) == InitSkippable: discard
+      elif allPathsAsgnResult(p, procBody) == InitSkippable: discard
       else:
         resetLoc(p, res.loc)
       if skipTypes(res.typ, abstractInst).kind == tyArray:
@@ -1196,13 +1232,13 @@ 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 and not isCppMember:
+    if hasDeclspec in extccomp.CC[p.config.cCompiler].props:
       header = "__declspec(noreturn) " & header
   if sfPure in prc.flags:
-    if hasDeclspec in extccomp.CC[p.config.cCompiler].props and not isCppMember:
+    if hasDeclspec in extccomp.CC[p.config.cCompiler].props:
       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)])
@@ -1247,7 +1283,7 @@ proc requiresExternC(m: BModule; sym: PSym): bool {.inline.} =
 
 proc genProcPrototype(m: BModule, sym: PSym) =
   useHeader(m, sym)
-  if lfNoDecl in sym.loc.flags or sfCppMember * sym.flags != {}: return
+  if lfNoDecl in sym.loc.flags or {sfVirtual, sfConstructor} * sym.flags != {}: return
   if lfDynamicLib in sym.loc.flags:
     if sym.itemId.module != m.module.position and
         not containsOrIncl(m.declaredThings, sym.id):
@@ -1426,21 +1462,17 @@ 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 =
@@ -1459,10 +1491,10 @@ 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)
@@ -1486,7 +1518,7 @@ 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"
@@ -1770,7 +1802,7 @@ proc genDatInitCode(m: BModule) =
 
   # we don't want to break into such init code - could happen if a line
   # directive from a function written by the user spills after itself
-  genCLineDir(prc, "generated_not_to_break_here", 999999, m.config)
+  genCLineDir(prc, InvalidFileIdx, 999999, m.config)
 
   for i in cfsTypeInit1..cfsDynLibInit:
     if m.s[i].len != 0:
@@ -1811,7 +1843,7 @@ proc genInitCode(m: BModule) =
     [rope(if m.hcrOn: "N_LIB_EXPORT" else: "N_LIB_PRIVATE"), initname]
   # we don't want to break into such init code - could happen if a line
   # directive from a function written by the user spills after itself
-  genCLineDir(prc, "generated_not_to_break_here", 999999, m.config)
+  genCLineDir(prc, InvalidFileIdx, 999999, m.config)
   if m.typeNodes > 0:
     if m.hcrOn:
       appcg(m, m.s[cfsTypeInit1], "\t#TNimNode* $1;$N", [m.typeNodesName])
@@ -1926,6 +1958,40 @@ proc genInitCode(m: BModule) =
 
   registerModuleToMain(m.g, m)
 
+proc postprocessCode(conf: ConfigRef, r: var Rope) =
+  # find the first directive
+  var f = r.find(postprocessDirStart)
+  if f == -1:
+    return
+
+  var
+    nimlnDirLastF = ""
+
+  var res: Rope = r.substr(0, f - 1)
+  while f != -1:
+    var
+      e = r.find(postprocessDirEnd, f + 1)
+      dir = r.substr(f + 1, e - 1).split(postprocessDirSep)
+    case dir[0]
+    of "nimln":
+      if dir[2] == nimlnDirLastF:
+        res.add("nimln_(" & dir[1] & ");")
+      else:
+        res.add("nimlf_(" & dir[1] & ", " & quotedFilename(conf, dir[2].parseInt.FileIndex) & ");")
+        nimlnDirLastF = dir[2]
+    else:
+      raiseAssert "unexpected postprocess directive"
+
+    # find the next directive
+    f = r.find(postprocessDirStart, e + 1)
+    # copy the code until the next directive
+    if f != -1:
+      res.add(r.substr(e + 1, f - 1))
+    else:
+      res.add(r.substr(e + 1))
+
+  r = res
+
 proc genModule(m: BModule, cfile: Cfile): Rope =
   var moduleIsEmpty = true
 
@@ -1954,9 +2020,17 @@ proc genModule(m: BModule, cfile: Cfile): Rope =
   if m.config.cppCustomNamespace.len > 0:
     closeNamespaceNim(result)
 
+  if optLineDir in m.config.options:
+    var srcFileDefs = ""
+    for fi in 0..m.config.m.fileInfos.high:
+      srcFileDefs.add("#define FX_" & $fi & " " & makeSingleLineCString(toFullPath(m.config, fi.FileIndex)) & "\n")
+    result = srcFileDefs & result
+
   if moduleIsEmpty:
     result = ""
 
+  postprocessCode(m.config, result)
+
 proc initProcOptions(m: BModule): TOptions =
   let opts = m.config.options
   if sfSystemModule in m.module.flags: opts-{optStackTrace} else: opts
@@ -1981,7 +2055,7 @@ 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
-  result.dataCache = initNodeTable()
+  initNodeTable(result.dataCache)
   result.typeStack = @[]
   result.typeNodesName = getTempName(result)
   result.nimTypesName = getTempName(result)
@@ -2158,7 +2232,6 @@ proc updateCachedModule(m: BModule) =
 
 proc finalCodegenActions*(graph: ModuleGraph; m: BModule; n: PNode): PNode =
   ## Also called from IC.
-  result = nil
   if sfMainModule in m.module.flags:
     # phase ordering problem here: We need to announce this
     # dependency to 'nimTestErrorFlag' before system.c has been written to disk.

compiler/cgendata.nim

@@ -135,6 +135,7 @@ type
                             # unconditionally...
                             # nimtvDeps is VERY hard to cache because it's
                             # not a list of IDs nor can it be made to be one.
+    mangledPrcs*: HashSet[string]
 
   TCGen = object of PPassContext # represents a C source file
     s*: TCFileSections        # sections of the C file
@@ -148,7 +149,7 @@ type
     typeABICache*: HashSet[SigHash] # cache for ABI checks; reusing typeCache
                               # would be ideal but for some reason enums
                               # don't seem to get cached so it'd generate
-                              # 1 ABI check per occurence in code
+                              # 1 ABI check per occurrence in code
     forwTypeCache*: TypeCache # cache for forward declarations of types
     declaredThings*: IntSet   # things we have declared in this .c file
     declaredProtos*: IntSet   # prototypes we have declared in this .c file

compiler/cgmeth.nim

@@ -44,8 +44,6 @@ 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
@@ -64,7 +62,6 @@ 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
@@ -98,7 +95,8 @@ 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]
@@ -152,7 +150,7 @@ proc fixupDispatcher(meth, disp: PSym; conf: ConfigRef) =
     disp.ast[resultPos] = copyTree(meth.ast[resultPos])
 
 proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
-  var witness: PSym = nil
+  var witness: PSym
   for i in 0..<g.methods.len:
     let disp = g.methods[i].dispatcher
     case sameMethodBucket(disp, s, multimethods = optMultiMethods in g.config.globalOptions)
@@ -181,7 +179,6 @@ proc methodDef*(g: ModuleGraph; idgen: IdGenerator; s: PSym) =
 
 proc relevantCol(methods: seq[PSym], col: int): bool =
   # returns true iff the position is relevant
-  result = false
   var t = methods[0].typ[col].skipTypes(skipPtrs)
   if t.kind == tyObject:
     for i in 1..high(methods):
@@ -190,7 +187,6 @@ 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)

compiler/closureiters.nim

@@ -258,9 +258,8 @@ proc hasYields(n: PNode): bool =
   of nkYieldStmt:
     result = true
   of nkSkip:
-    result = false
+    discard
   else:
-    result = false
     for c in n:
       if c.hasYields:
         result = true
@@ -326,7 +325,7 @@ proc collectExceptState(ctx: var Ctx, n: PNode): PNode {.inline.} =
       var ifBranch: PNode
 
       if c.len > 1:
-        var cond: PNode = nil
+        var cond: PNode
         for i in 0..<c.len - 1:
           assert(c[i].kind == nkType)
           let nextCond = newTree(nkCall,
@@ -389,22 +388,19 @@ proc getFinallyNode(ctx: var Ctx, n: PNode): PNode =
 proc hasYieldsInExpressions(n: PNode): bool =
   case n.kind
   of nkSkip:
-    result = false
+    discard
   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
@@ -499,7 +495,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
 
     if ns:
       needsSplit = true
-      var tmp: PSym = nil
+      var tmp: PSym
       let isExpr = not isEmptyType(n.typ)
       if isExpr:
         tmp = ctx.newTempVar(n.typ)
@@ -1365,7 +1361,6 @@ 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

@@ -55,6 +55,11 @@ proc loadConfigsAndProcessCmdLine*(self: NimProg, cache: IdentCache; conf: Confi
   if conf.cmd == cmdNimscript:
     incl(conf.globalOptions, optWasNimscript)
   loadConfigs(DefaultConfig, cache, conf, graph.idgen) # load all config files
+  # restores `conf.notes` after loading config files
+  # because it has overwrites the notes when compiling the system module which
+  # is a foreign module compared to the project
+  if conf.cmd in cmdBackends:
+    conf.notes = conf.mainPackageNotes
 
   if not self.suggestMode:
     let scriptFile = conf.projectFull.changeFileExt("nims")

compiler/commands.nim

@@ -184,7 +184,7 @@ proc processSpecificNote*(arg: string, state: TSpecialWord, pass: TCmdLinePass,
                          info: TLineInfo; orig: string; conf: ConfigRef) =
   var id = ""  # arg = key or [key] or key:val or [key]:val;  with val=on|off
   var i = 0
-  var notes: set[TMsgKind] = {}
+  var notes: set[TMsgKind]
   var isBracket = false
   if i < arg.len and arg[i] == '[':
     isBracket = true
@@ -205,7 +205,11 @@ 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}
@@ -263,17 +267,13 @@ 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:
-      result = false
-      localError(conf, info, errNoneBoehmRefcExpectedButXFound % arg)
+    else: 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:
-      result = false
-      localError(conf, info, errNoneSpeedOrSizeExpectedButXFound % arg)
+    else: localError(conf, info, errNoneSpeedOrSizeExpectedButXFound % arg)
   of "verbosity": result = $conf.verbosity == arg
   of "app":
     case arg.normalize
@@ -283,9 +283,7 @@ 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:
-      result = false
-      localError(conf, info, errGuiConsoleOrLibExpectedButXFound % arg)
+    else: localError(conf, info, errGuiConsoleOrLibExpectedButXFound % arg)
   of "dynliboverride":
     result = isDynlibOverride(conf, arg)
   of "exceptions":
@@ -294,12 +292,8 @@ 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:
-      result = false
-      localError(conf, info, errInvalidExceptionSystem % arg)
-  else:
-    result = false
-    invalidCmdLineOption(conf, passCmd1, switch, info)
+    else: localError(conf, info, errInvalidExceptionSystem % arg)
+  else: invalidCmdLineOption(conf, passCmd1, switch, info)
 
 proc testCompileOption*(conf: ConfigRef; switch: string, info: TLineInfo): bool =
   case switch.normalize
@@ -345,14 +339,10 @@ 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)
-    result = false
+  of "nilseqs", "nilchecks", "taintmode": warningOptionNoop(switch)
   of "panics": result = contains(conf.globalOptions, optPanics)
   of "jsbigint64": result = contains(conf.globalOptions, optJsBigInt64)
-  else:
-    result = false
-    invalidCmdLineOption(conf, passCmd1, switch, info)
+  else: invalidCmdLineOption(conf, passCmd1, switch, info)
 
 proc processPath(conf: ConfigRef; path: string, info: TLineInfo,
                  notRelativeToProj = false): AbsoluteDir =
@@ -394,8 +384,7 @@ 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: int = 0
-  var col: int = 0
+  var ln, col: int
   if parseUtils.parseInt(line, ln) <= 0:
     localError(conf, info, errInvalidNumber % line)
   if parseUtils.parseInt(column, col) <= 0:
@@ -606,8 +595,8 @@ proc processMemoryManagementOption(switch, arg: string, pass: TCmdLinePass,
 
 proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
                     conf: ConfigRef) =
-  var key = ""
-  var val = ""
+  var
+    key, val: string
   case switch.normalize
   of "eval":
     expectArg(conf, switch, arg, pass, info)
@@ -622,7 +611,8 @@ 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":
+  of "nimblepath", "babelpath":
+    if switch.normalize == "babelpath": deprecatedAlias(switch, "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)
@@ -632,7 +622,8 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
         nimblePath(conf, path, info)
         path = nimbleDir / RelativeDir"pkgs"
       nimblePath(conf, path, info)
-  of "nonimblepath":
+  of "nonimblepath", "nobabelpath":
+    if switch.normalize == "nobabelpath": deprecatedAlias(switch, "nonimblepath")
     expectNoArg(conf, switch, arg, pass, info)
     disableNimblePath(conf)
   of "clearnimblepath":
@@ -1122,8 +1113,7 @@ 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 = ""
-  var arg = ""
+  var cmd, arg: string
   splitSwitch(config, switch, cmd, arg, pass, gCmdLineInfo)
   processSwitch(cmd, arg, pass, gCmdLineInfo, config)
 
@@ -1150,10 +1140,7 @@ proc processArgument*(pass: TCmdLinePass; p: OptParser;
       config.projectName = unixToNativePath(p.key)
       config.arguments = cmdLineRest(p)
       result = true
-    elif pass != passCmd2:
-      setCommandEarly(config, p.key)
-      result = false
-    else: result = false
+    elif pass != passCmd2: setCommandEarly(config, p.key)
   else:
     if pass == passCmd1: config.commandArgs.add p.key
     if argsCount == 1:
@@ -1164,6 +1151,4 @@ 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

@@ -121,11 +121,8 @@ 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:
@@ -159,17 +156,15 @@ 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[0], a[0], m)
+      result = matchType(c, f.sons[0], a.sons[0], m)
     elif m.magic == mArrPut:
-      result = matchType(c, f[0], a, m)
+      result = matchType(c, f.sons[0], a, m)
     else:
       result = false
   of tyEnum, tyObject, tyDistinct:
@@ -190,7 +185,6 @@ 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:
@@ -215,7 +209,6 @@ 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!
@@ -264,7 +257,7 @@ 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[0], candidate.typ[0], m):
+  if not matchReturnType(c, n[0].sym.typ.sons[0], candidate.typ.sons[0], m):
     m.inferred.setLen oldLen
     return false
 
@@ -321,7 +314,7 @@ proc conceptMatchNode(c: PContext; n: PNode; m: var MatchCon): bool =
 
 proc conceptMatch*(c: PContext; concpt, arg: PType; bindings: var TIdTable; invocation: PType): bool =
   ## Entry point from sigmatch. 'concpt' is the concept we try to match (here still a PType but
-  ## we extract its AST via 'concpt.n.lastSon'). 'arg' is the type that might fullfill the
+  ## we extract its AST via 'concpt.n.lastSon'). 'arg' is the type that might fulfill the
   ## concept's requirements. If so, we return true and fill the 'bindings' with pairs of
   ## (typeVar, instance) pairs. ('typeVar' is usually simply written as a generic 'T'.)
   ## 'invocation' can be nil for atomic concepts. For non-atomic concepts, it contains the

compiler/condsyms.nim

@@ -158,6 +158,6 @@ proc initDefines*(symbols: StringTableRef) =
   defineSymbol("nimAllowNonVarDestructor")
   defineSymbol("nimHasQuirky")
   defineSymbol("nimHasEnsureMove")
+  defineSymbol("nimHasNoReturnError")
 
-  defineSymbol("nimUseStrictDefs")
-  defineSymbol("nimHasNolineTooLong")
+  defineSymbol("nimHasCastExtendedVm")

compiler/depends.nim

@@ -42,7 +42,7 @@ proc toNimblePath(s: string, isStdlib: bool): string =
     let sub = "lib/"
     var start = s.find(sub)
     if start < 0:
-      raiseAssert "unreachable"
+      doAssert false
     else:
       start += sub.len
       let base = s[start..^1]
@@ -105,6 +105,11 @@ proc generateDot*(graph: ModuleGraph; project: AbsoluteFile) =
             changeFileExt(project, "dot"))
 
 proc setupDependPass*(graph: ModuleGraph; module: PSym; idgen: IdGenerator): PPassContext =
-  result = PGen(module: module, config: graph.config, graph: graph)
+  var g: PGen
+  new(g)
+  g.module = module
+  g.config = graph.config
+  g.graph = graph
   if graph.backend == nil:
     graph.backend = Backend(dotGraph: "")
+  result = g

compiler/dfa.nim

@@ -60,7 +60,6 @@ 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:
@@ -112,7 +111,7 @@ 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])
@@ -264,7 +263,7 @@ 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):
@@ -470,7 +469,7 @@ 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: raiseAssert "dfa construction pass requires the elimination of 'defer'"
+  of nkDefer: doAssert false, "dfa construction pass requires the elimination of 'defer'"
   else: discard
 
 when false:

compiler/docgen.nim

@@ -170,7 +170,6 @@ 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"
 
@@ -216,16 +215,12 @@ 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])
@@ -348,7 +343,7 @@ proc newDocumentor*(filename: AbsoluteFile; cache: IdentCache; conf: ConfigRef,
 
   if conf.configVars.hasKey("doc.googleAnalytics") and
       conf.configVars.hasKey("doc.plausibleAnalytics"):
-    raiseAssert "Either use googleAnalytics or plausibleAnalytics"
+    doAssert false, "Either use googleAnalytics or plausibleAnalytics"
 
   if conf.configVars.hasKey("doc.googleAnalytics"):
     result.analytics = """
@@ -373,7 +368,7 @@ proc newDocumentor*(filename: AbsoluteFile; cache: IdentCache; conf: ConfigRef,
   result.seenSymbols = newStringTable(modeCaseInsensitive)
   result.id = 100
   result.jEntriesFinal = newJArray()
-  result.types = initStrTable()
+  initStrTable result.types
   result.onTestSnippet =
     proc (gen: var RstGenerator; filename, cmd: string; status: int; content: string) {.gcsafe.} =
       if conf.docCmd == docCmdSkip: return
@@ -440,8 +435,6 @@ 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
@@ -476,7 +469,6 @@ 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
@@ -492,8 +484,9 @@ proc externalDep(d: PDoc; module: PSym): string =
 proc nodeToHighlightedHtml(d: PDoc; n: PNode; result: var string;
                            renderFlags: TRenderFlags = {};
                            procLink: string) =
-  var r: TSrcGen = initTokRender(n, renderFlags)
+  var r: TSrcGen
   var literal = ""
+  initTokRender(r, n, renderFlags)
   var kind = tkEof
   var tokenPos = 0
   var procTokenPos = 0
@@ -607,9 +600,7 @@ 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 = ""
-  result.addQuoted(a)
+proc quoted(a: string): string = result.addQuoted(a)
 
 proc toInstantiationInfo(conf: ConfigRef, info: TLineInfo): (string, int, int) =
   # xxx expose in compiler/lineinfos.nim
@@ -735,7 +726,7 @@ 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
@@ -951,17 +942,14 @@ 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:
-    raiseAssert "unreachable"
+    doAssert false
 
 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(), '/')
@@ -1003,7 +991,7 @@ 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:
@@ -1028,7 +1016,8 @@ proc toLangSymbol(k: TSymKind, n: PNode, baseName: string): LangSymbol =
         genNode = n[miscPos][1]   # FIXME: what is index 1?
     if genNode != nil:
       var literal = ""
-      var r: TSrcGen = initTokRender(genNode, {renderNoBody, renderNoComments,
+      var r: TSrcGen
+      initTokRender(r, genNode, {renderNoBody, renderNoComments,
         renderNoPragmas, renderNoProcDefs, renderExpandUsing})
       var kind = tkEof
       while true:
@@ -1049,14 +1038,15 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
   var result = ""
   var literal, plainName = ""
   var kind = tkEof
-  var comm: ItemPre = default(ItemPre)
+  var comm: 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.
-  var r: TSrcGen = initTokRender(n, {renderNoBody, renderNoComments, renderDocComments,
+  initTokRender(r, n, {renderNoBody, renderNoComments, renderDocComments,
     renderNoPragmas, renderNoProcDefs, renderExpandUsing})
   while true:
     getNextTok(r, kind, literal)
@@ -1164,7 +1154,7 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
     renderFlags = {renderNoBody, renderNoComments, renderDocComments, renderExpandUsing}
   if nonExports:
     renderFlags.incl renderNonExportedFields
-  r = initTokRender(n, renderFlags)
+  initTokRender(r, n, renderFlags)
   result.json = %{ "name": %name, "type": %($k), "line": %n.info.line.int,
                    "col": %n.info.col}
   if comm != nil:
@@ -1196,9 +1186,9 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
       result.json["signature"]["genericParams"] = newJArray()
       for genericParam in n[genericParamsPos]:
         var param = %{"name": %($genericParam)}
-        if genericParam.sym.typ.len > 0:
+        if genericParam.sym.typ.sons.len > 0:
           param["types"] = newJArray()
-        for kind in genericParam.sym.typ:
+        for kind in genericParam.sym.typ.sons:
           param["types"].add %($kind)
         result.json["signature"]["genericParams"].add param
   if optGenIndex in d.conf.globalOptions:
@@ -1293,8 +1283,6 @@ 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)
@@ -1317,8 +1305,6 @@ 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
@@ -1332,8 +1318,6 @@ 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
@@ -1407,7 +1391,7 @@ 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 = default(ItemPre)
+    var comm: ItemPre
     getAllRunnableExamples(d, n, comm)
     if comm.len != 0: d.modDescPre.add(comm)
   else: discard
@@ -1516,7 +1500,7 @@ 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") % (
@@ -1542,7 +1526,7 @@ 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
@@ -1657,7 +1641,7 @@ 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") % [
@@ -1688,7 +1672,7 @@ 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 = ""
@@ -1797,7 +1781,7 @@ 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,
@@ -1809,7 +1793,7 @@ proc writeOutputJson*(d: PDoc, useWarning = false) =
   else:
     let dir = d.destFile.splitFile.dir
     createDir(dir)
-    var f: File = default(File)
+    var f: File
     if open(f, d.destFile, fmWrite):
       write(f, $content)
       close(f)

compiler/docgen2.nim

@@ -39,12 +39,10 @@ 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

@@ -56,7 +56,6 @@ 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

compiler/evalffi.nim

@@ -11,7 +11,7 @@
 
 import ast, types, options, tables, dynlib, msgs, lineinfos
 from os import getAppFilename
-import libffi/libffi
+import pkg/libffi
 
 when defined(windows):
   const libcDll = "msvcrt.dll"
@@ -37,10 +37,9 @@ 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)
@@ -62,7 +61,7 @@ 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 = nil
+    var theAddr: pointer
     if (lib.isNil or lib.kind == libHeader) and not gExeHandle.isNil:
       libPathMsg = "current exe: " & getAppFilename() & " nor libc: " & libcDll
       # first try this exe itself:
@@ -109,7 +108,6 @@ 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))[]
@@ -134,8 +132,6 @@ 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
 
@@ -144,7 +140,6 @@ 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
@@ -159,8 +154,7 @@ 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: result = nil
-  else: result = nil
+  else: discard
 
 proc packObject(conf: ConfigRef, x: PNode, typ: PType, res: pointer) =
   internalAssert conf, x.kind in {nkObjConstr, nkPar, nkTupleConstr}
@@ -362,7 +356,6 @@ 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))
@@ -388,7 +381,6 @@ 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)
@@ -406,7 +398,6 @@ 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 =
@@ -433,7 +424,7 @@ proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =
   internalAssert conf, call[0].kind == nkPtrLit
 
   var cif: TCif
-  var sig: ParamList = default(ParamList)
+  var sig: ParamList
   # use the arguments' types for varargs support:
   for i in 1..<call.len:
     sig[i-1] = mapType(conf, call[i].typ)
@@ -445,7 +436,7 @@ proc callForeignFunction*(conf: ConfigRef, call: PNode): PNode =
               mapType(conf, typ[0]), sig) != OK:
     globalError(conf, call.info, "error in FFI call")
 
-  var args: ArgList = default(ArgList)
+  var args: ArgList
   let fn = cast[pointer](call[0].intVal)
   for i in 1..<call.len:
     var t = call[i].typ
@@ -473,7 +464,7 @@ proc callForeignFunction*(conf: ConfigRef, fn: PNode, fntyp: PType,
   internalAssert conf, fn.kind == nkPtrLit
 
   var cif: TCif
-  var sig: ParamList = default(ParamList)
+  var sig: ParamList
   for i in 0..len-1:
     var aTyp = args[i+start].typ
     if aTyp.isNil:
@@ -487,7 +478,7 @@ proc callForeignFunction*(conf: ConfigRef, fn: PNode, fntyp: PType,
               mapType(conf, fntyp[0]), sig) != OK:
     globalError(conf, info, "error in FFI call")
 
-  var cargs: ArgList = default(ArgList)
+  var cargs: ArgList
   let fn = cast[pointer](fn.intVal)
   for i in 0..len-1:
     let t = args[i+start].typ

compiler/evaltempl.nim

@@ -56,6 +56,7 @@ proc evalTemplateAux(templ, actual: PNode, c: var TemplCtx, result: PNode) =
           #  internalAssert c.config, false
           idTablePut(c.mapping, s, x)
         if sfGenSym in s.flags:
+          # TODO: getIdent(c.ic, "`" & x.name.s & "`gensym" & $c.instID)
           result.add newIdentNode(getIdent(c.ic, x.name.s & "`gensym" & $c.instID),
             if c.instLines: actual.info else: templ.info)
         else:
@@ -187,7 +188,7 @@ proc evalTemplate*(n: PNode, tmpl, genSymOwner: PSym;
   ctx.genSymOwner = genSymOwner
   ctx.config = conf
   ctx.ic = ic
-  ctx.mapping = initIdTable()
+  initIdTable(ctx.mapping)
   ctx.instID = instID[]
   ctx.idgen = idgen
 

compiler/extccomp.nim

@@ -19,7 +19,7 @@ import std/[os, osproc, streams, sequtils, times, strtabs, json, jsonutils, suga
 import std / strutils except addf
 
 when defined(nimPreviewSlimSystem):
-  import std/syncio
+  import std/[syncio, assertions]
 
 import ../dist/checksums/src/checksums/sha1
 
@@ -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:
@@ -486,10 +487,6 @@ 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 & " "
@@ -538,7 +535,7 @@ 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 = 0
+      var major: int
       discard parseInt(s, major)
       result = major >= 5
   else:
@@ -648,7 +645,7 @@ 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 = default(File)
+  var f: File
   if open(f, hashFile.string, fmRead):
     let oldHash = parseSecureHash(f.readLine())
     close(f)
@@ -783,7 +780,6 @@ 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
@@ -866,7 +862,6 @@ 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)
@@ -889,15 +884,15 @@ 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 = default(TStringSeq)
-  var prettyCmds: TStringSeq = default(TStringSeq)
+  var cmds: TStringSeq
+  var prettyCmds: TStringSeq
   let prettyCb = proc (idx: int) = writePrettyCmdsStderr(prettyCmds[idx])
 
   for idx, it in conf.toCompile:
@@ -998,7 +993,7 @@ type BuildCache = object
   depfiles: seq[(string, string)]
   nimexe: string
 
-proc writeJsonBuildInstructions*(conf: ConfigRef) =
+proc writeJsonBuildInstructions*(conf: ConfigRef; deps: StringTableRef) =
   var linkFiles = collect(for it in conf.externalToLink:
     var it = it
     if conf.noAbsolutePaths: it = it.extractFilename
@@ -1019,18 +1014,21 @@ proc writeJsonBuildInstructions*(conf: ConfigRef) =
     currentDir: getCurrentDir())
   if optRun in conf.globalOptions or isDefined(conf, "nimBetterRun"):
     bcache.cmdline = conf.commandLine
-    bcache.depfiles = collect(for it in conf.m.fileInfos:
+    for it in conf.m.fileInfos:
       let path = it.fullPath.string
       if isAbsolute(path): # TODO: else?
-        (path, $secureHashFile(path)))
+        if path in deps:
+          bcache.depfiles.add (path, deps[path])
+        else: # backup for configs etc.
+          bcache.depfiles.add (path, $secureHashFile(path))
+
     bcache.nimexe = hashNimExe()
   conf.jsonBuildFile = conf.jsonBuildInstructionsFile
   conf.jsonBuildFile.string.writeFile(bcache.toJson.pretty)
 
 proc changeDetectedViaJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile): bool =
-  result = false
   if not fileExists(jsonFile) or not fileExists(conf.absOutFile): return true
-  var bcache: BuildCache = default(BuildCache)
+  var bcache: BuildCache
   try: bcache.fromJson(jsonFile.string.parseFile)
   except IOError, OSError, ValueError:
     stderr.write "Warning: JSON processing failed for: $#\n" % jsonFile.string
@@ -1046,7 +1044,7 @@ proc changeDetectedViaJsonBuildInstructions*(conf: ConfigRef; jsonFile: Absolute
     if $secureHashFile(file) != hash: return true
 
 proc runJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile) =
-  var bcache: BuildCache = default(BuildCache)
+  var bcache: BuildCache
   try: bcache.fromJson(jsonFile.string.parseFile)
   except ValueError, KeyError, JsonKindError:
     let e = getCurrentException()
@@ -1059,8 +1057,7 @@ 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: TStringSeq = default(TStringSeq)
-  var prettyCmds: TStringSeq= default(TStringSeq)
+  var cmds, prettyCmds: TStringSeq
   let prettyCb = proc (idx: int) = writePrettyCmdsStderr(prettyCmds[idx])
   for (name, cmd) in bcache.compile:
     cmds.add cmd
@@ -1070,7 +1067,6 @@ proc runJsonBuildInstructions*(conf: ConfigRef; jsonFile: AbsoluteFile) =
   for cmd in bcache.extraCmds: execExternalProgram(conf, cmd, hintExecuting)
 
 proc genMappingFiles(conf: ConfigRef; list: CfileList): Rope =
-  result = ""
   for it in list:
     result.addf("--file:r\"$1\"$N", [rope(it.cname.string)])
 

compiler/filter_tmpl.nim

@@ -201,15 +201,17 @@ proc parseLine(p: var TTmplParser) =
 
 proc filterTmpl*(conf: ConfigRef, stdin: PLLStream, filename: AbsoluteFile,
                  call: PNode): PLLStream =
-  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)
-                )
+  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)
   # do not process the first line which contains the directive:
   if llStreamReadLine(p.inp, p.x):
     inc p.info.line

compiler/filters.nim

@@ -29,30 +29,23 @@ 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:
-    result = default(char)
-    invalidPragma(conf, n)
+  else: 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:
-    result = ""
-    invalidPragma(conf, n)
+  else: 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:
-    result = false
-    invalidPragma(conf, n)
+  else: invalidPragma(conf, n)
 
 proc filterStrip*(conf: ConfigRef; stdin: PLLStream, filename: AbsoluteFile, call: PNode): PLLStream =
   var pattern = strArg(conf, call, "startswith", 1, "")

compiler/gorgeimpl.nim

@@ -29,11 +29,10 @@ 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 = default(File)
+    var f: File
     if optForceFullMake notin conf.globalOptions and open(f, filename):
       result = (f.readAll, 0)
       f.close

compiler/guards.nim

@@ -51,10 +51,6 @@ 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
@@ -140,8 +136,6 @@ 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)
@@ -336,8 +330,6 @@ 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'
@@ -345,18 +337,12 @@ 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)
@@ -370,14 +356,10 @@ 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...
@@ -394,8 +376,6 @@ 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
@@ -404,12 +384,8 @@ 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
@@ -475,9 +451,8 @@ proc hasSubTree(n, x: PNode): bool =
     of nkEmpty..nkNilLit:
       result = n.sameTree(x)
     of nkFormalParams:
-      result = false
+      discard
     else:
-      result = false
       for i in 0..<n.len:
         if hasSubTree(n[i], x): return true
 
@@ -508,8 +483,6 @@ 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)
@@ -520,26 +493,16 @@ 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
-    else:
-      result = impUnknown
-  of mNot, mOr, mAnd:
-    result = impUnknown
-    assert(false, "impliesEq")
-  else: result = impUnknown
+  of mNot, mOr, mAnd: assert(false, "impliesEq")
+  else: discard
 
 proc leImpliesIn(x, c, aSet: PNode): TImplication =
   if c.kind in {nkCharLit..nkUInt64Lit}:
@@ -549,19 +512,13 @@ 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 = 0
+      var i, pos, neg: int
       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}:
@@ -572,23 +529,17 @@ 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 = 0
+      var i, pos, neg: int
       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
@@ -599,32 +550,22 @@ 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)
-    else:
-      result = impUnknown
-  of mNot, mOr, mAnd:
-    result = impUnknown
-    assert(false, "impliesIn")
-  else: result = impUnknown
+  of mNot, mOr, mAnd: assert(false, "impliesIn")
+  else: discard
 
 proc valueIsNil(n: PNode): TImplication =
   if n.kind == nkNilLit: impYes
@@ -636,19 +577,13 @@ 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)
-    else:
-      result = impUnknown
-  of mNot, mOr, mAnd:
-    result = impUnknown
-    assert(false, "impliesIsNil")
-  else: result = impUnknown
+  of mNot, mOr, mAnd: assert(false, "impliesIsNil")
+  else: discard
 
 proc impliesGe(fact, x, c: PNode): TImplication =
   assert isLocation(x)
@@ -659,57 +594,32 @@ 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
-        else: result = impUnknown
-      else:
-        result = impUnknown
-    else:
-      result = impUnknown
-  of mNot, mOr, mAnd:
-    result = impUnknown
-    assert(false, "impliesGe")
-  else: result = impUnknown
+  of mNot, mOr, mAnd: assert(false, "impliesGe")
+  else: discard
 
 proc impliesLe(fact, x, c: PNode): TImplication =
   if not isLocation(x):
@@ -724,59 +634,35 @@ 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:
-    result = impUnknown
-    assert(false, "impliesLe")
-  else: result = impUnknown
+  of mNot, mOr, mAnd: assert(false, "impliesLe")
+  else: discard
 
 proc impliesLt(fact, x, c: PNode): TImplication =
   # x < 3  same as x <= 2:
@@ -788,8 +674,6 @@ 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
@@ -841,7 +725,6 @@ 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:
@@ -1017,7 +900,6 @@ 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:
@@ -1099,7 +981,7 @@ proc addFactLt*(m: var TModel; a, b: PNode) =
 
 proc settype(n: PNode): PType =
   result = newType(tySet, ItemId(module: -1, item: -1), n.typ.owner)
-  var idgen: IdGenerator = nil
+  var idgen: IdGenerator
   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 =
@@ -20,11 +17,9 @@ 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):
-      renderTree(n, {renderNoComments})
-    else:
-      ""
+  var rule: string
+  if c.config.hasHint(hintPattern):
+    rule = renderTree(n, {renderNoComments})
   let s = n[0].sym
   case s.kind
   of skMacro:
@@ -75,7 +70,7 @@ 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} * n[0].sym.flags == {sfGlobal, sfPure}:
       # do not optimize 'var g {.global} = re(...)' again!
       return n
     result = applyPatterns(c, n)

compiler/ic/cbackend.nim

@@ -101,7 +101,7 @@ proc aliveSymsChanged(config: ConfigRef; position: int; alive: AliveSyms): bool
   var f2 = rodfiles.open(asymFile.string)
   f2.loadHeader()
   f2.loadSection aliveSymsSection
-  var oldData: seq[int32] = @[]
+  var oldData: seq[int32]
   f2.loadSeq(oldData)
   f2.close
   if f2.err == ok and oldData == s:

compiler/ic/dce.nim

@@ -40,14 +40,10 @@ proc isExportedToC(c: var AliveContext; g: PackedModuleGraph; symId: int32): boo
     if ({sfExportc, sfCompilerProc} * flags != {}) or
         (symPtr.kind == skMethod):
       result = true
-    else:
-      result = false
       # XXX: This used to be a condition to:
       #  (sfExportc in prc.flags and lfExportLib in prc.loc.flags) or
     if sfCompilerProc in flags:
       c.compilerProcs[g[c.thisModule].fromDisk.strings[symPtr.name]] = (c.thisModule, symId)
-  else:
-    result = false
 
 template isNotGeneric(n: NodePos): bool = ithSon(tree, n, genericParamsPos).kind == nkEmpty
 

compiler/ic/ic.nim

@@ -359,7 +359,7 @@ proc storeType(t: PType; c: var PackedEncoder; m: var PackedModule): PackedItemI
       paddingAtEnd: t.paddingAtEnd)
     storeNode(p, t, n)
     p.typeInst = t.typeInst.storeType(c, m)
-    for kid in items t:
+    for kid in items t.sons:
       p.types.add kid.storeType(c, m)
     c.addMissing t.sym
     p.sym = t.sym.safeItemId(c, m)
@@ -421,7 +421,7 @@ proc addModuleRef(n: PNode; ir: var PackedTree; c: var PackedEncoder; m: var Pac
   ## 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)
+                          typeId: storeTypeLater(n.typ, c, m), info: info, flags: n.flags)
   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,
@@ -813,7 +813,6 @@ 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:
@@ -917,7 +916,7 @@ proc typeBodyFromPacked(c: var PackedDecoder; g: var PackedModuleGraph;
       result.attachedOps[op] = loadSym(c, g, si, item)
   result.typeInst = loadType(c, g, si, t.typeInst)
   for son in items t.types:
-    result.addSon loadType(c, g, si, son)
+    result.sons.add loadType(c, g, si, son)
   loadAstBody(t, n)
   when false:
     for gen, id in items t.methods:
@@ -1148,8 +1147,6 @@ 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 =
@@ -1167,15 +1164,11 @@ 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;
@@ -1208,7 +1201,7 @@ proc searchForCompilerproc*(m: LoadedModule; name: string): int32 =
 # ------------------------- .rod file viewer ---------------------------------
 
 proc rodViewer*(rodfile: AbsoluteFile; config: ConfigRef, cache: IdentCache) =
-  var m: PackedModule = PackedModule()
+  var m: PackedModule
   let err = loadRodFile(rodfile, m, config, ignoreConfig=true)
   if err != ok:
     config.quitOrRaise "Error: could not load: " & $rodfile.string & " reason: " & $err

compiler/ic/navigator.nim

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

compiler/ic/packed_ast.nim

@@ -305,7 +305,6 @@ proc sons3*(tree: PackedTree; n: NodePos): (NodePos, NodePos, NodePos) =
   result = (NodePos a, NodePos b, NodePos c)
 
 proc ithSon*(tree: PackedTree; n: NodePos; i: int): NodePos =
-  result = default(NodePos)
   if tree.nodes[n.int].kind > nkNilLit:
     var count = 0
     for child in sonsReadonly(tree, n):

compiler/ic/rodfiles.nim

@@ -215,7 +215,7 @@ proc storeHeader*(f: var RodFile) =
 proc loadHeader*(f: var RodFile) =
   ## Loads the header which is described by `cookie`.
   if f.err != ok: return
-  var thisCookie: array[cookie.len, byte] = default(array[cookie.len, byte])
+  var thisCookie: array[cookie.len, byte]
   if f.f.readBytes(thisCookie, 0, thisCookie.len) != thisCookie.len:
     setError f, ioFailure
   elif thisCookie != cookie:
@@ -231,14 +231,13 @@ 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 = default(RodSection)
+  var s: 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
 
@@ -246,6 +245,5 @@ proc close*(f: var RodFile) = close(f.f)
 
 proc open*(filename: string): RodFile =
   ## open the file for reading
-  result = default(RodFile)
   if not open(result.f, filename, fmRead):
     setError result, cannotOpen

compiler/importer.nim

@@ -113,7 +113,6 @@ 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]
@@ -305,11 +304,17 @@ proc myImportModule(c: PContext, n: var PNode, importStmtResult: PNode): PSym =
       var prefix = ""
       if realModule.constraint != nil: prefix = realModule.constraint.strVal & "; "
       message(c.config, n.info, warnDeprecated, prefix & realModule.name.s & " is deprecated")
-    suggestSym(c.graph, n.info, result, c.graph.usageSym, false)
+
+    proc suggestMod(n: PNode; s: PSym) =
+      if n.kind == nkImportAs:
+        suggestMod(n[0], realModule)
+      elif n.kind == nkInfix:
+        suggestMod(n[2], s)
+      else:
+        suggestSym(c.graph, n.info, s, c.graph.usageSym, false)
+    suggestMod(n, result)
     importStmtResult.add newSymNode(result, n.info)
     #newStrNode(toFullPath(c.config, f), n.info)
-  else:
-    result = nil
 
 proc afterImport(c: PContext, m: PSym) =
   # fixes bug #17510, for re-exported symbols
@@ -347,9 +352,11 @@ proc evalImport*(c: PContext, n: PNode): PNode =
           imp[lastPos] = x[1]
           impAs[1] = imp
           impAs[2] = x[2]
+          impAs.info = x[2].info
           impMod(c, impAs, result)
         else:
           imp[lastPos] = x
+          imp.info = x.info
           impMod(c, imp, result)
     else:
       impMod(c, it, result)

compiler/injectdestructors.nim

@@ -161,7 +161,8 @@ proc isLastReadImpl(n: PNode; c: var Con; scope: var Scope): bool =
     result = false
 
 proc isLastRead(n: PNode; c: var Con; s: var Scope): bool =
-  if not hasDestructor(c, n.typ): return true
+  # bug #23354; an object type could have a non-trival assignements when it is passed to a sink parameter
+  if not hasDestructor(c, n.typ) and (n.typ.kind != tyObject or isTrival(getAttachedOp(c.graph, n.typ, attachedAsgn))): return true
 
   let m = skipConvDfa(n)
   result = (m.kind == nkSym and sfSingleUsedTemp in m.sym.flags) or
@@ -295,7 +296,7 @@ proc genSink(c: var Con; s: var Scope; dest, ri: PNode; flags: set[MoveOrCopyFla
 proc isCriticalLink(dest: PNode): bool {.inline.} =
   #[
   Lins's idea that only "critical" links can introduce a cycle. This is
-  critical for the performance gurantees that we strive for: If you
+  critical for the performance guarantees that we strive for: If you
   traverse a data structure, no tracing will be performed at all.
   ORC is about this promise: The GC only touches the memory that the
   mutator touches too.
@@ -314,7 +315,7 @@ proc isCriticalLink(dest: PNode): bool {.inline.} =
 
 proc finishCopy(c: var Con; result, dest: PNode; isFromSink: bool) =
   if c.graph.config.selectedGC == gcOrc:
-    let t = dest.typ.skipTypes({tyGenericInst, tyAlias, tySink, tyDistinct})
+    let t = dest.typ.skipTypes(tyUserTypeClasses + {tyGenericInst, tyAlias, tySink, tyDistinct})
     if cyclicType(c.graph, t):
       result.add boolLit(c.graph, result.info, isFromSink or isCriticalLink(dest))
 
@@ -407,7 +408,10 @@ proc genDefaultCall(t: PType; c: Con; info: TLineInfo): PNode =
 proc destructiveMoveVar(n: PNode; c: var Con; s: var Scope): PNode =
   # generate: (let tmp = v; reset(v); tmp)
   if (not hasDestructor(c, n.typ)) and c.inEnsureMove == 0:
-    assert n.kind != nkSym or not hasDestructor(c, n.sym.typ)
+    assert n.kind != nkSym or not hasDestructor(c, n.sym.typ) or
+          (n.typ.kind == tyPtr and n.sym.typ.kind == tyRef)
+      # bug #23505; transformed by `transf`: addr (deref ref) -> ptr
+      # we know it's really a pointer; so here we assign it directly
     result = copyTree(n)
   else:
     result = newNodeIT(nkStmtListExpr, n.info, n.typ)
@@ -434,22 +438,22 @@ proc destructiveMoveVar(n: PNode; c: var Con; s: var Scope): PNode =
 proc isCapturedVar(n: PNode): bool =
   let root = getRoot(n)
   if root != nil: result = root.name.s[0] == ':'
-  else: result = false
 
 proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
   result = newNodeIT(nkStmtListExpr, n.info, n.typ)
-  let tmp = c.getTemp(s, n.typ, n.info)
-  if hasDestructor(c, n.typ):
-    let typ = n.typ.skipTypes({tyGenericInst, tyAlias, tySink})
+  let nTyp = n.typ.skipTypes(tyUserTypeClasses)
+  let tmp = c.getTemp(s, nTyp, n.info)
+  if hasDestructor(c, nTyp):
+    let typ = nTyp.skipTypes({tyGenericInst, tyAlias, tySink})
     let op = getAttachedOp(c.graph, typ, attachedDup)
     if op != nil and tfHasOwned notin typ.flags:
       if sfError in op.flags:
-        c.checkForErrorPragma(n.typ, n, "=dup")
+        c.checkForErrorPragma(nTyp, n, "=dup")
       else:
         let copyOp = getAttachedOp(c.graph, typ, attachedAsgn)
         if copyOp != nil and sfError in copyOp.flags and
            sfOverridden notin op.flags:
-          c.checkForErrorPragma(n.typ, n, "=dup", inferredFromCopy = true)
+          c.checkForErrorPragma(nTyp, n, "=dup", inferredFromCopy = true)
 
       let src = p(n, c, s, normal)
       var newCall = newTreeIT(nkCall, src.info, src.typ,
@@ -466,7 +470,7 @@ proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
       m.add p(n, c, s, normal)
       c.finishCopy(m, n, isFromSink = true)
       result.add m
-    if isLValue(n) and not isCapturedVar(n) and n.typ.skipTypes(abstractInst).kind != tyRef and c.inSpawn == 0:
+    if isLValue(n) and not isCapturedVar(n) and nTyp.skipTypes(abstractInst).kind != tyRef and c.inSpawn == 0:
       message(c.graph.config, n.info, hintPerformance,
         ("passing '$1' to a sink parameter introduces an implicit copy; " &
         "if possible, rearrange your program's control flow to prevent it") % $n)
@@ -475,8 +479,8 @@ proc passCopyToSink(n: PNode; c: var Con; s: var Scope): PNode =
         ("cannot move '$1', passing '$1' to a sink parameter introduces an implicit copy") % $n)
   else:
     if c.graph.config.selectedGC in {gcArc, gcOrc, gcAtomicArc}:
-      assert(not containsManagedMemory(n.typ))
-    if n.typ.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
+      assert(not containsManagedMemory(nTyp))
+    if nTyp.skipTypes(abstractInst).kind in {tyOpenArray, tyVarargs}:
       localError(c.graph.config, n.info, "cannot create an implicit openArray copy to be passed to a sink parameter")
     result.add newTree(nkAsgn, tmp, p(n, c, s, normal))
   # Since we know somebody will take over the produced copy, there is
@@ -590,7 +594,9 @@ template processScopeExpr(c: var Con; s: var Scope; ret: PNode, processCall: unt
   # tricky because you would have to intercept moveOrCopy at a certain point
   let tmp = c.getTemp(s.parent[], ret.typ, ret.info)
   tmp.sym.flags = tmpFlags
-  let cpy = if hasDestructor(c, ret.typ):
+  let cpy = if hasDestructor(c, ret.typ) and
+                ret.typ.kind notin {tyOpenArray, tyVarargs}:
+                # bug #23247 we don't own the data, so it's harmful to destroy it
               s.parent[].final.add c.genDestroy(tmp)
               moveOrCopy(tmp, ret, c, s, {IsDecl})
             else:
@@ -736,9 +742,7 @@ template handleNestedTempl(n, processCall: untyped, willProduceStmt = false,
     result[^1] = maybeVoid(n[^1], s)
     dec c.inUncheckedAssignSection, inUncheckedAssignSection
 
-  else:
-    result = nil
-    assert(false)
+  else: 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:
@@ -765,6 +769,18 @@ proc pRaiseStmt(n: PNode, c: var Con; s: var Scope): PNode =
       result.add copyNode(n[0])
   s.needsTry = true
 
+template isCustomDestructor(c: Con, t: PType): bool =
+  hasDestructor(c, t) and
+          getAttachedOp(c.graph, t, attachedDestructor) != nil and
+          sfOverridden in getAttachedOp(c.graph, t, attachedDestructor).flags
+
+proc hasCustomDestructor(c: Con, t: PType): bool =
+  result = isCustomDestructor(c, t)
+  var obj = t
+  while obj.len > 0 and obj[0] != nil:
+    obj = skipTypes(obj[0], abstractPtrs)
+    result = result or isCustomDestructor(c, obj)
+
 proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSingleUsedTemp}; inReturn = false): PNode =
   if n.kind in {nkStmtList, nkStmtListExpr, nkBlockStmt, nkBlockExpr, nkIfStmt,
                 nkIfExpr, nkCaseStmt, nkWhen, nkWhileStmt, nkParForStmt, nkTryStmt, nkPragmaBlock}:
@@ -855,7 +871,7 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
             result[i][1] = p(n[i][1], c, s, m)
         else:
           result[i] = p(n[i], c, s, m)
-      if mode == normal and isRefConstr:
+      if mode == normal and (isRefConstr or hasCustomDestructor(c, t)):
         result = ensureDestruction(result, n, c, s)
     of nkCallKinds:
       if n[0].kind == nkSym and n[0].sym.magic == mEnsureMove:
@@ -901,7 +917,10 @@ proc p(n: PNode; c: var Con; s: var Scope; mode: ProcessMode; tmpFlags = {sfSing
         result[0] = p(n[0], c, s, normal)
       if canRaise(n[0]): s.needsTry = true
       if mode == normal:
-        result = ensureDestruction(result, n, c, s)
+        if result.typ != nil and result.typ.kind notin {tyOpenArray, tyVarargs}:
+          # Returns of openarray types shouldn't be destroyed
+          # bug #19435; # bug #23247
+          result = ensureDestruction(result, n, c, s)
     of nkDiscardStmt: # Small optimization
       result = shallowCopy(n)
       if n[0].kind != nkEmpty:
@@ -1049,7 +1068,6 @@ 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 =
@@ -1161,8 +1179,7 @@ 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) and
-          not ({sfGlobal, sfPure} <= ri.sym.flags):
+          isLastRead(ri, c, s) and canBeMoved(c, dest.typ) and not isCursor(ri):
         # 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

@@ -10,7 +10,7 @@ Platforms: """
   macosx: i386;amd64;powerpc64;arm64
   solaris: i386;amd64;sparc;sparc64
   freebsd: i386;amd64;powerpc64;arm;arm64;riscv64;sparc64;mips;mipsel;mips64;mips64el;powerpc;powerpc64el
-  netbsd: i386;amd64
+  netbsd: i386;amd64;arm64
   openbsd: i386;amd64;arm;arm64
   dragonfly: i386;amd64
   crossos: amd64

compiler/int128.nim

@@ -171,7 +171,6 @@ 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) =
@@ -331,8 +330,8 @@ proc `*`*(a: Int128, b: int32): Int128 =
   if b < 0:
     result = -result
 
-proc `*=`(a: var Int128, b: int32) =
-  a = a * b
+proc `*=`*(a: var Int128, b: int32): Int128 =
+  result = result * b
 
 proc makeInt128(high, low: uint64): Int128 =
   result.udata[0] = cast[uint32](low)
@@ -361,7 +360,6 @@ proc `*=`*(a: var Int128, b: Int128) =
 import bitops
 
 proc fastLog2*(a: Int128): int =
-  result = 0
   if a.udata[3] != 0:
     return 96 + fastLog2(a.udata[3])
   if a.udata[2] != 0:

compiler/isolation_check.nim

@@ -21,7 +21,6 @@ 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
@@ -37,7 +36,7 @@ proc canAliasN(arg: PType; n: PNode; marker: var IntSet): bool =
       else: discard
   of nkSym:
     result = canAlias(arg, n.sym.typ, marker)
-  else: result = false
+  else: discard
 
 proc canAlias(arg, ret: PType; marker: var IntSet): bool =
   if containsOrIncl(marker, ret.id):
@@ -57,7 +56,6 @@ 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
@@ -186,12 +184,10 @@ 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
@@ -201,7 +197,6 @@ 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

@@ -32,7 +32,7 @@ import
   ast, trees, magicsys, options,
   nversion, msgs, idents, types,
   ropes, ccgutils, wordrecg, renderer,
-  cgmeth, lowerings, sighashes, modulegraphs, lineinfos,
+  cgmeth, lowerings, sighashes, modulegraphs, lineinfos, rodutils,
   transf, injectdestructors, sourcemap, astmsgs, backendpragmas
 
 import pipelineutils
@@ -43,7 +43,6 @@ import strutils except addf
 when defined(nimPreviewSlimSystem):
   import std/[assertions, syncio]
 
-import std/formatfloat
 
 type
   TJSGen = object of PPassContext
@@ -138,15 +137,17 @@ template nested(p, body) =
   dec p.extraIndent
 
 proc newGlobals(): PGlobals =
-  result = PGlobals(forwarded: @[],
-        generatedSyms: initIntSet(),
-        typeInfoGenerated: initIntSet()
-        )
+  new(result)
+  result.forwarded = @[]
+  result.generatedSyms = initIntSet()
+  result.typeInfoGenerated = initIntSet()
 
-proc initCompRes(): TCompRes =
-  result = TCompRes(address: "", res: "",
-    tmpLoc: "", typ: etyNone, kind: resNone
-  )
+proc initCompRes(r: var TCompRes) =
+  r.address = ""
+  r.res = ""
+  r.tmpLoc = ""
+  r.typ = etyNone
+  r.kind = resNone
 
 proc rdLoc(a: TCompRes): Rope {.inline.} =
   if a.typ != etyBaseIndex:
@@ -218,8 +219,7 @@ proc mapType(typ: PType): TJSTypeKind =
     else: result = etyNone
   of tyProc: result = etyProc
   of tyCstring: result = etyString
-  of tyConcept, tyIterable:
-    raiseAssert "unreachable"
+  of tyConcept, tyIterable: doAssert false
 
 proc mapType(p: PProc; typ: PType): TJSTypeKind =
   result = mapType(typ)
@@ -348,7 +348,8 @@ proc isSimpleExpr(p: PProc; n: PNode): bool =
       if n[i].kind notin {nkCommentStmt, nkEmpty}: return false
     result = isSimpleExpr(p, n.lastSon)
   else:
-    result = n.isAtom
+    if n.isAtom:
+      result = true
 
 proc getTemp(p: PProc, defineInLocals: bool = true): Rope =
   inc(p.unique)
@@ -358,7 +359,7 @@ 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 = default(TCompRes)
+  var x, y: TCompRes
   if p.isSimpleExpr(a) and p.isSimpleExpr(b):
     gen(p, a, x)
     gen(p, b, y)
@@ -385,7 +386,7 @@ 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 = default(TCompRes)
+  var x, y: TCompRes
   if p.isSimpleExpr(a) and p.isSimpleExpr(b):
     gen(p, a, x)
     gen(p, b, y)
@@ -473,7 +474,6 @@ 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:
@@ -509,8 +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 = default(TCompRes)
-        first: Int128 = Zero
+        address, index: TCompRes
+        first: Int128
       gen(p, n[0], address)
       gen(p, n[1], index)
       let (m1, tmp1) = maybeMakeTemp(p, n[0], address)
@@ -542,7 +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 = default(TCompRes)
+  var x, y: TCompRes
   useMagic(p, magic)
   gen(p, n[1], x)
   gen(p, n[2], y)
@@ -572,7 +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 = default(TCompRes)
+  var x, y: TCompRes
   gen(p, n[1], x)
   gen(p, n[2], y)
   let size = n[1].typ.skipTypes(abstractRange).size
@@ -611,8 +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 = default(TCompRes)
-    xLoc, yLoc: Rope = ""
+    x, y: TCompRes
+    xLoc, yLoc: Rope
   let i = ord(optOverflowCheck notin p.options)
   useMagic(p, jsMagics[op][i])
   if n.len > 2:
@@ -676,38 +676,8 @@ 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:
-    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 mSucc: applyFormat("addInt($1, $2)", "($1 + $2)")
+  of mPred: applyFormat("subInt($1, $2)", "($1 - $2)")
   of mAddF64: applyFormat("($1 + $2)", "($1 + $2)")
   of mSubF64: applyFormat("($1 - $2)", "($1 - $2)")
   of mMulF64: applyFormat("($1 * $2)", "($1 * $2)")
@@ -833,7 +803,7 @@ proc arith(p: PProc, n: PNode, r: var TCompRes, op: TMagic) =
     if mapType(n[1].typ) != etyBaseIndex:
       arithAux(p, n, r, op)
     else:
-      var x, y: TCompRes = default(TCompRes)
+      var x, y: TCompRes
       gen(p, n[1], x)
       gen(p, n[2], y)
       r.res = "($# == $# && $# == $#)" % [x.address, y.address, x.res, y.res]
@@ -866,7 +836,7 @@ proc genLineDir(p: PProc, n: PNode) =
       p.previousFileName = currentFileName
 
 proc genWhileStmt(p: PProc, n: PNode) =
-  var cond: TCompRes = default(TCompRes)
+  var cond: TCompRes
   internalAssert p.config, isEmptyType(n.typ)
   genLineDir(p, n)
   inc(p.unique)
@@ -961,7 +931,6 @@ 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("||")
@@ -1002,7 +971,7 @@ proc genTry(p: PProc, n: PNode, r: var TCompRes) =
 
 proc genRaiseStmt(p: PProc, n: PNode) =
   if n[0].kind != nkEmpty:
-    var a: TCompRes = default(TCompRes)
+    var a: TCompRes
     gen(p, n[0], a)
     let typ = skipTypes(n[0].typ, abstractPtrs)
     genLineDir(p, n)
@@ -1016,7 +985,7 @@ proc genRaiseStmt(p: PProc, n: PNode) =
 
 proc genCaseJS(p: PProc, n: PNode, r: var TCompRes) =
   var
-    a, b, cond, stmt: TCompRes = default(TCompRes)
+    a, b, cond, stmt: TCompRes
   genLineDir(p, n)
   gen(p, n[0], cond)
   let typeKind = skipTypes(n[0].typ, abstractVar).kind
@@ -1150,7 +1119,7 @@ proc genAsmOrEmitStmt(p: PProc, n: PNode) =
       if false:
         discard
       else:
-        var r = default(TCompRes)
+        var r: TCompRes
         gen(p, it, r)
 
         if it.typ.kind == tyPointer:
@@ -1166,13 +1135,13 @@ proc genAsmOrEmitStmt(p: PProc, n: PNode) =
 
         p.body.add(r.rdLoc)
     else:
-      var r: TCompRes = default(TCompRes)
+      var r: 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 = default(TCompRes)
+  var cond, stmt: TCompRes
   var toClose = 0
   if not isEmptyType(n.typ):
     r.kind = resVal
@@ -1209,7 +1178,6 @@ 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
@@ -1230,10 +1198,10 @@ proc needsNoCopy(p: PProc; y: PNode): bool =
   return y.kind in nodeKindsNeedNoCopy or
         ((mapType(y.typ) != etyBaseIndex or (y.kind == nkSym and y.sym.kind == skParam)) and
           (skipTypes(y.typ, abstractInst).kind in
-            {tyRef, tyPtr, tyLent, tyVar, tyCstring, tyProc, tyOwned} + IntegralTypes))
+            {tyRef, tyPtr, tyLent, tyVar, tyCstring, tyProc, tyOwned, tyOpenArray} + IntegralTypes))
 
 proc genAsgnAux(p: PProc, x, y: PNode, noCopyNeeded: bool) =
-  var a, b: TCompRes = default(TCompRes)
+  var a, b: TCompRes
   var xtyp = mapType(p, x.typ)
 
   # disable `[]=` for cstring
@@ -1312,7 +1280,7 @@ proc genFastAsgn(p: PProc, n: PNode) =
   genAsgnAux(p, n[0], n[1], noCopyNeeded=noCopy)
 
 proc genSwap(p: PProc, n: PNode) =
-  var a, b: TCompRes = default(TCompRes)
+  var a, b: TCompRes
   gen(p, n[1], a)
   gen(p, n[2], b)
   var tmp = p.getTemp(false)
@@ -1330,12 +1298,10 @@ proc getFieldPosition(p: PProc; f: PNode): int =
   case f.kind
   of nkIntLit..nkUInt64Lit: result = int(f.intVal)
   of nkSym: result = f.sym.position
-  else:
-    result = 0
-    internalError(p.config, f.info, "genFieldPosition")
+  else: internalError(p.config, f.info, "genFieldPosition")
 
 proc genFieldAddr(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes = default(TCompRes)
+  var a: TCompRes
   r.typ = etyBaseIndex
   let b = if n.kind == nkHiddenAddr: n[0] else: n
   gen(p, b[0], a)
@@ -1399,10 +1365,10 @@ 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 = default(TCompRes)
+  var setx: TCompRes
   gen(p, checkExpr[1], setx)
 
-  var obj: TCompRes = default(TCompRes)
+  var obj: TCompRes
   gen(p, accessExpr[0], obj)
   # Avoid evaluating the LHS twice (one to read the discriminant and one to read
   # the field)
@@ -1428,8 +1394,8 @@ proc genCheckedFieldOp(p: PProc, n: PNode, addrTyp: PType, r: var TCompRes) =
 
 proc genArrayAddr(p: PProc, n: PNode, r: var TCompRes) =
   var
-    a, b: TCompRes = default(TCompRes)
-    first: Int128 = Zero
+    a, b: TCompRes
+    first: Int128
   r.typ = etyBaseIndex
   let m = if n.kind == nkHiddenAddr: n[0] else: n
   gen(p, m[0], a)
@@ -1676,7 +1642,7 @@ 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 = default(TCompRes)
+    var a: TCompRes
     gen(p, it, a)
     r.kind = a.kind
     r.typ = mapType(p, n.typ)
@@ -1693,7 +1659,7 @@ 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 = default(TCompRes)
+  var a: TCompRes
   gen(p, n, a)
   if a.typ == etyBaseIndex:
     r.res.add(a.address)
@@ -1703,7 +1669,7 @@ 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 = default(TCompRes)
+  var a: TCompRes
   gen(p, n, a)
   if skipTypes(param.typ, abstractVar).kind in {tyOpenArray, tyVarargs} and
       a.typ == etyBaseIndex:
@@ -1827,7 +1793,7 @@ proc genInfixCall(p: PProc, n: PNode, r: var TCompRes) =
       r.address = ""
       r.typ = etyNone
     r.res.add(".")
-  var op: TCompRes = default(TCompRes)
+  var op: TCompRes
   gen(p, n[0], op)
   r.res.add(op.res)
   genArgs(p, n, r, 2)
@@ -1975,7 +1941,7 @@ 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]
@@ -1986,7 +1952,7 @@ proc createVar(p: PProc, typ: PType, indirect: bool): Rope =
       result = putToSeq("null", indirect)
   of tySequence, tyString:
     result = putToSeq("[]", indirect)
-  of tyCstring, tyProc:
+  of tyCstring, tyProc, tyOpenArray:
     result = putToSeq("null", indirect)
   of tyStatic:
     if t.n != nil:
@@ -2002,7 +1968,7 @@ template returnType: untyped = ""
 
 proc genVarInit(p: PProc, v: PSym, n: PNode) =
   var
-    a: TCompRes = default(TCompRes)
+    a: TCompRes
     s: Rope
     varCode: string
     varName = mangleName(p.module, v)
@@ -2103,7 +2069,7 @@ proc genConstant(p: PProc, c: PSym) =
     p.body = oldBody
 
 proc genNew(p: PProc, n: PNode) =
-  var a: TCompRes = default(TCompRes)
+  var a: TCompRes
   gen(p, n[1], a)
   var t = skipTypes(n[1].typ, abstractVar)[0]
   if mapType(t) == etyObject:
@@ -2114,7 +2080,7 @@ 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 = default(TCompRes)
+  var x, y: TCompRes
   gen(p, n[1], x)
   gen(p, n[2], y)
   let t = skipTypes(n[1].typ, abstractVar)[0]
@@ -2132,7 +2098,7 @@ 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 = default(TCompRes)
+  var a: TCompRes
 
   gen(p, n[1], a)
   r.kind = resExpr
@@ -2157,7 +2123,7 @@ 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 = default(TCompRes)
+  var a: TCompRes
 
   gen(p, n[1], a)
   if magic == "reprAny":
@@ -2204,7 +2170,7 @@ proc genRepr(p: PProc, n: PNode, r: var TCompRes) =
   r.kind = resExpr
 
 proc genOf(p: PProc, n: PNode, r: var TCompRes) =
-  var x: TCompRes = default(TCompRes)
+  var x: TCompRes
   let t = skipTypes(n[2].typ,
                     abstractVarRange+{tyRef, tyPtr, tyLent, tyTypeDesc, tyOwned})
   gen(p, n[1], x)
@@ -2220,7 +2186,7 @@ proc genDefault(p: PProc, n: PNode; r: var TCompRes) =
   r.kind = resExpr
 
 proc genReset(p: PProc, n: PNode) =
-  var x: TCompRes = default(TCompRes)
+  var x: TCompRes
   useMagic(p, "genericReset")
   gen(p, n[1], x)
   if x.typ == etyBaseIndex:
@@ -2231,7 +2197,7 @@ proc genReset(p: PProc, n: PNode) =
                   genTypeInfo(p, n[1].typ), tmp])
 
 proc genMove(p: PProc; n: PNode; r: var TCompRes) =
-  var a: TCompRes = default(TCompRes)
+  var a: TCompRes
   r.kind = resVal
   r.res = p.getTemp()
   gen(p, n[1], a)
@@ -2240,14 +2206,14 @@ 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 = default(TCompRes)
+  var a: 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 = default(TCompRes)
+  var a: TCompRes
   r.res = rope("[")
   r.kind = resExpr
   for i in 0 ..< n.len:
@@ -2278,7 +2244,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
     binaryExpr(p, n, r, "addChar",
         "addChar($1, $2);")
   of mAppendStrStr:
-    var lhs, rhs: TCompRes = default(TCompRes)
+    var lhs, rhs: TCompRes
     gen(p, n[1], lhs)
     gen(p, n[2], rhs)
 
@@ -2291,7 +2257,7 @@ 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 = default(TCompRes)
+    var x, y: TCompRes
     gen(p, n[1], x)
     gen(p, n[2], y)
     if mapType(n[2].typ) == etyBaseIndex:
@@ -2319,7 +2285,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
     if mapType(n[1].typ) != etyBaseIndex:
       unaryExpr(p, n, r, "", "($1 == null)")
     else:
-      var x: TCompRes = default(TCompRes)
+      var x: TCompRes
       gen(p, n[1], x)
       r.res = "($# == null && $# === 0)" % [x.address, x.res]
   of mEnumToStr: genRepr(p, n, r)
@@ -2330,7 +2296,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
     if n[1].kind == nkBracket:
       genJSArrayConstr(p, n[1], r)
     else:
-      var x: TCompRes = default(TCompRes)
+      var x: TCompRes
       gen(p, n[1], x)
       useMagic(p, "nimCopy")
       r.res = "nimCopy(null, $1, $2)" % [x.rdLoc, genTypeInfo(p, n.typ)]
@@ -2339,7 +2305,7 @@ 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 = default(TCompRes)
+    var x: TCompRes
     gen(p, n[1], x)
     if skipTypes(n[1].typ, abstractInst).kind == tyCstring:
       let (a, tmp) = maybeMakeTemp(p, n[1], x)
@@ -2348,7 +2314,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
       r.res = "($1).length" % [x.rdLoc]
     r.kind = resExpr
   of mHigh:
-    var x: TCompRes = default(TCompRes)
+    var x: TCompRes
     gen(p, n[1], x)
     if skipTypes(n[1].typ, abstractInst).kind == tyCstring:
       let (a, tmp) = maybeMakeTemp(p, n[1], x)
@@ -2380,7 +2346,7 @@ 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)
@@ -2393,7 +2359,7 @@ 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 = default(TCompRes)
+    var x, y: TCompRes
     gen(p, n[1], x)
     gen(p, n[2], y)
     let t = skipTypes(n[1].typ, abstractVar)[0]
@@ -2432,7 +2398,7 @@ 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 = default(TCompRes)
+    var x, y, z: TCompRes
     gen(p, n[1], x)
     gen(p, n[2], y)
     gen(p, n[3], z)
@@ -2450,7 +2416,7 @@ proc genMagic(p: PProc, n: PNode, r: var TCompRes) =
 
 proc genSetConstr(p: PProc, n: PNode, r: var TCompRes) =
   var
-    a, b: TCompRes = default(TCompRes)
+    a, b: TCompRes
   useMagic(p, "setConstr")
   r.res = rope("setConstr(")
   r.kind = resExpr
@@ -2487,7 +2453,7 @@ 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 = default(TCompRes)
+    var a: TCompRes
     r.res = "new $1([" % [rope(jsTyp)]
     r.kind = resExpr
     for i in 0 ..< n.len:
@@ -2499,7 +2465,7 @@ 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 = default(TCompRes)
+  var a: TCompRes
   r.res = rope("{")
   r.kind = resExpr
   for i in 0..<n.len:
@@ -2518,9 +2484,9 @@ proc genTupleConstr(p: PProc, n: PNode, r: var TCompRes) =
   r.res.add("}")
 
 proc genObjConstr(p: PProc, n: PNode, r: var TCompRes) =
-  var a: TCompRes = default(TCompRes)
+  var a: 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:
@@ -2594,23 +2560,16 @@ 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 = default(TCompRes)
+  var a, b: TCompRes
   gen(p, n[0], r)
   let src = skipTypes(n[0].typ, abstractVarRange)
   let dest = skipTypes(n.typ, abstractVarRange)
-  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]
+  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"
   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")
@@ -2687,10 +2646,9 @@ proc optionalLine(p: Rope): Rope =
 
 proc genProc(oldProc: PProc, prc: PSym): Rope =
   ## Generate a JS procedure ('function').
-  result = ""
   var
     resultSym: PSym
-    a: TCompRes = default(TCompRes)
+    a: TCompRes
   #if gVerbosity >= 3:
   #  echo "BEGIN generating code for: " & prc.name.s
   var p = newProc(oldProc.g, oldProc.module, prc.ast, prc.options)
@@ -2770,7 +2728,7 @@ proc genProc(oldProc: PProc, prc: PSym): Rope =
   #  echo "END   generated code for: " & prc.name.s
 
 proc genStmt(p: PProc, n: PNode) =
-  var r: TCompRes = default(TCompRes)
+  var r: TCompRes
   gen(p, n, r)
   if r.res != "": lineF(p, "$#;$n", [r.res])
 
@@ -2901,11 +2859,7 @@ proc gen(p: PProc, n: PNode, r: var TCompRes) =
       r.res = rope"Infinity"
     of fcNegInf:
       r.res = rope"-Infinity"
-    else:
-      if n.typ.skipTypes(abstractVarRange).kind == tyFloat32:
-        r.res.addFloatRoundtrip(f.float32)
-      else:
-        r.res.addFloatRoundtrip(f)
+    else: r.res = rope(f.toStrMaxPrecision)
     r.kind = resExpr
   of nkCallKinds:
     if isEmptyType(n.typ):
@@ -3006,11 +2960,13 @@ 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 = BModule(module: module, sigConflicts: initCountTable[SigHash](),
-                   graph: g, config: g.config
-  )
+  result.graph = g
+  result.config = g.config
   if sfSystemModule in module.flags:
     PGlobals(g.backend).inSystem = true
 

compiler/lambdalifting.nim

@@ -187,8 +187,6 @@ 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
@@ -201,8 +199,6 @@ 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
@@ -262,8 +258,7 @@ proc liftIterSym*(g: ModuleGraph; n: PNode; idgen: IdGenerator; owner: PSym): PN
   let iter = n.sym
   assert iter.isIterator
 
-  result = newNodeIT(nkStmtListExpr, n.info, n.typ)
-
+  result = newNodeIT(nkStmtListExpr, n.info, iter.typ)
   let hp = getHiddenParam(g, iter)
   var env: PNode
   if owner.isIterator:
@@ -316,14 +311,17 @@ type
     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 = DetectionPass(processed: toIntSet([fn.id]),
-    capturedVars: initIntSet(), ownerToType: initTable[int, PType](),
-    graph: g, idgen: idgen
-  )
+  result.processed = initIntSet()
+  result.capturedVars = initIntSet()
+  result.ownerToType = initTable[int, PType]()
+  result.processed.incl(fn.id)
+  result.graph = g
+  result.idgen = idgen
 
 discard """
 proc outer =
@@ -417,6 +415,9 @@ 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
@@ -455,7 +456,8 @@ proc detectCapturedVars(n: PNode; owner: PSym; c: var DetectionPass) =
         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})
 
@@ -481,10 +483,12 @@ 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:
@@ -516,9 +520,14 @@ 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
@@ -528,8 +537,9 @@ type
     unownedEnvVars: Table[int, PNode] # only required for --newruntime
 
 proc initLiftingPass(fn: PSym): LiftingPass =
-  result = LiftingPass(processed: toIntSet([fn.id]),
-                envVars: initTable[int, PNode]())
+  result.processed = initIntSet()
+  result.processed.incl(fn.id)
+  result.envVars = initTable[int, PNode]()
 
 proc accessViaEnvParam(g: ModuleGraph; n: PNode; owner: PSym): PNode =
   let s = n.sym
@@ -716,7 +726,6 @@ 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;
@@ -798,6 +807,8 @@ proc liftCapturedVars(n: PNode; owner: PSym; d: var DetectionPass;
   of nkTypeOfExpr:
     result = n
   else:
+    if n.isCallExpr and n[0].isTypeOf:
+      return
     if owner.isIterator:
       if nfLL in n.flags:
         # special case 'when nimVm' due to bug #3636:
@@ -942,7 +953,7 @@ proc liftForLoop*(g: ModuleGraph; body: PNode; idgen: IdGenerator; owner: PSym):
   result = newNodeI(nkStmtList, body.info)
 
   # static binding?
-  var env: PSym = nil
+  var env: PSym
   let op = call[0]
   if op.kind == nkSym and op.sym.isIterator:
     # createClosure()
@@ -977,12 +988,15 @@ proc liftForLoop*(g: ModuleGraph; body: PNode; idgen: IdGenerator; owner: PSym):
   # gather vars in a tuple:
   var v2 = newNodeI(nkLetSection, body.info)
   var vpart = newNodeI(if body.len == 3: nkIdentDefs else: nkVarTuple, body.info)
-  for i in 0..<body.len-2:
-    if body[i].kind == nkSym:
-      body[i].sym.transitionToLet()
-    vpart.add body[i]
+  if body.len == 3 and body[0].kind == nkVarTuple:
+    vpart = body[0] # fixes for (i,j) in walk() # bug #15924
+  else:
+    for i in 0..<body.len-2:
+      if body[i].kind == nkSym:
+        body[i].sym.transitionToLet()
+      vpart.add body[i]
 
-  vpart.add newNodeI(nkEmpty, body.info) # no explicit type
+    vpart.add newNodeI(nkEmpty, body.info) # no explicit type
   if not env.isNil:
     call[0] = makeClosure(g, idgen, call[0].sym, env.newSymNode, body.info)
   vpart.add call

compiler/lexer.nim

@@ -148,11 +148,9 @@ 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 false
+      if i < sLen and s[i] notin SymChars: return
       inc(i)
     result = true
-  else:
-    result = false
 
 proc `$`*(tok: Token): string =
   case tok.tokType
@@ -539,8 +537,8 @@ proc getNumber(L: var Lexer, result: var Token) =
         of floatTypes:
           result.fNumber = parseFloat(result.literal)
         of tkUInt64Lit, tkUIntLit:
-          var iNumber: uint64 = uint64(0)
-          var len: int = 0
+          var iNumber: uint64
+          var len: int
           try:
             len = parseBiggestUInt(result.literal, iNumber)
           except ValueError:
@@ -549,8 +547,8 @@ proc getNumber(L: var Lexer, result: var Token) =
             raise newException(ValueError, "invalid integer: " & result.literal)
           result.iNumber = cast[int64](iNumber)
         else:
-          var iNumber: int64 = int64(0)
-          var len: int = 0
+          var iNumber: int64
+          var len: int
           try:
             len = parseBiggestInt(result.literal, iNumber)
           except ValueError:
@@ -1009,7 +1007,6 @@ proc getPrecedence*(tok: Token): int =
   else: return -10
 
 proc newlineFollows*(L: Lexer): bool =
-  result = false
   var pos = L.bufpos
   while true:
     case L.buf[pos]
@@ -1397,9 +1394,8 @@ proc rawGetTok*(L: var Lexer, tok: var Token) =
 
 proc getIndentWidth*(fileIdx: FileIndex, inputstream: PLLStream;
                      cache: IdentCache; config: ConfigRef): int =
-  result = 0
-  var lex: Lexer = default(Lexer)
-  var tok: Token = default(Token)
+  var lex: Lexer
+  var tok: Token
   initToken(tok)
   openLexer(lex, fileIdx, inputstream, cache, config)
   var prevToken = tkEof

compiler/liftdestructors.nim

@@ -39,7 +39,7 @@ template asink*(t: PType): PSym = getAttachedOp(c.g, t, attachedSink)
 
 proc fillBody(c: var TLiftCtx; t: PType; body, x, y: PNode)
 proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator): PSym
+              info: TLineInfo; idgen: IdGenerator; isDistinct = false): PSym
 
 proc createTypeBoundOps*(g: ModuleGraph; c: PContext; orig: PType; info: TLineInfo;
                          idgen: IdGenerator)
@@ -156,17 +156,18 @@ proc genWasMovedCall(c: var TLiftCtx; op: PSym; x: PNode): PNode =
   result.add(newSymNode(op))
   result.add genAddr(c, x)
 
-proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool) =
+proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool, enforceWasMoved = false) =
   case n.kind
   of nkSym:
     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:
+      if enforceWasMoved:
+        body.add genBuiltin(c, mWasMoved, "`=wasMoved`", x.dotField(f))
       fillBody(c, f.typ, body, x.dotField(f), b)
   of nkNilLit: discard
   of nkRecCase:
@@ -205,7 +206,7 @@ proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool)
       branch[^1] = newNodeI(nkStmtList, c.info)
 
       fillBodyObj(c, n[i].lastSon, branch[^1], x, y,
-                  enforceDefaultOp = localEnforceDefaultOp)
+                  enforceDefaultOp = localEnforceDefaultOp, enforceWasMoved = c.kind == attachedAsgn)
       if branch[^1].len == 0: inc emptyBranches
       caseStmt.add(branch)
     if emptyBranches != n.len-1:
@@ -216,13 +217,16 @@ proc fillBodyObj(c: var TLiftCtx; n, body, x, y: PNode; enforceDefaultOp: bool)
       fillBodyObj(c, n[0], body, x, y, enforceDefaultOp = false)
     c.filterDiscriminator = oldfilterDiscriminator
   of nkRecList:
-    for t in items(n): fillBodyObj(c, t, body, x, y, enforceDefaultOp)
+    for t in items(n): fillBodyObj(c, t, body, x, y, enforceDefaultOp, enforceWasMoved)
   else:
     illFormedAstLocal(n, c.g.config)
 
 proc fillBodyObjTImpl(c: var TLiftCtx; t: PType, body, x, y: PNode) =
   if t.len > 0 and t[0] != nil:
-    fillBody(c, skipTypes(t[0], abstractPtrs), body, x, y)
+    let obj = newNodeIT(nkHiddenSubConv, c.info, t[0])
+    obj.add newNodeI(nkEmpty, c.info)
+    obj.add x
+    fillBody(c, skipTypes(t[0], abstractPtrs), body, obj, y)
   fillBodyObj(c, t.n, body, x, y, enforceDefaultOp = false)
 
 proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
@@ -279,6 +283,7 @@ proc fillBodyObjT(c: var TLiftCtx; t: PType, body, x, y: PNode) =
     c.kind = attachedDestructor
     fillBodyObjTImpl(c, t, body, blob, y)
     c.kind = prevKind
+
   else:
     fillBodyObjTImpl(c, t, body, x, y)
 
@@ -302,7 +307,7 @@ 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[1].kind == tyVar:
+  if op.typ.sons[1].kind == tyVar:
     result.add genAddr(c, x)
   else:
     result.add x
@@ -367,8 +372,6 @@ 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):
@@ -398,8 +401,6 @@ 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})
@@ -439,8 +440,6 @@ 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)
@@ -461,8 +460,6 @@ 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)
@@ -477,8 +474,6 @@ 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)
@@ -493,8 +488,6 @@ 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)
@@ -554,6 +547,14 @@ 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:
@@ -561,10 +562,13 @@ 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:
@@ -1024,7 +1028,7 @@ 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: raiseAssert "unreachable"
+  of tyConcept, tyIterable: doAssert false
 
 proc produceSymDistinctType(g: ModuleGraph; c: PContext; typ: PType;
                             kind: TTypeAttachedOp; info: TLineInfo;
@@ -1032,7 +1036,9 @@ proc produceSymDistinctType(g: ModuleGraph; c: PContext; typ: PType;
   assert typ.kind == tyDistinct
   let baseType = typ[0]
   if getAttachedOp(g, baseType, kind) == nil:
-    discard produceSym(g, c, baseType, kind, info, idgen)
+    # TODO: fixme `isDistinct` is a fix for #23552; remove it after
+    # `-d:nimPreviewNonVarDestructor` becomes the default
+    discard produceSym(g, c, baseType, kind, info, idgen, isDistinct = true)
   result = getAttachedOp(g, baseType, kind)
   setAttachedOp(g, idgen.module, typ, kind, result)
 
@@ -1071,7 +1077,7 @@ 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; isDistinct = false): PSym =
   if kind == attachedDup:
     return symDupPrototype(g, typ, owner, kind, info, idgen)
 
@@ -1081,7 +1087,7 @@ 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 typ.kind in {tyRef, tyString, tySequence} and g.config.selectedGC in {gcArc, gcOrc, gcAtomicArc} and not isDistinct:
     dest.typ = typ
   else:
     dest.typ = makeVarType(typ.owner, typ, idgen)
@@ -1123,13 +1129,13 @@ proc genTypeFieldCopy(c: var TLiftCtx; t: PType; body, x, y: PNode) =
   body.add newAsgnStmt(xx, yy)
 
 proc produceSym(g: ModuleGraph; c: PContext; typ: PType; kind: TTypeAttachedOp;
-              info: TLineInfo; idgen: IdGenerator): PSym =
+              info: TLineInfo; idgen: IdGenerator; isDistinct = false): PSym =
   if typ.kind == tyDistinct:
     return produceSymDistinctType(g, c, typ, kind, info, idgen)
 
   result = getAttachedOp(g, typ, kind)
   if result == nil:
-    result = symPrototype(g, typ, typ.owner, kind, info, idgen)
+    result = symPrototype(g, typ, typ.owner, kind, info, idgen, isDistinct = isDistinct)
 
   var a = TLiftCtx(info: info, g: g, kind: kind, c: c, asgnForType: typ, idgen: idgen,
                    fn: result)
@@ -1226,7 +1232,7 @@ proc inst(g: ModuleGraph; c: PContext; t: PType; kind: TTypeAttachedOp; idgen: I
     else:
       localError(g.config, info, "unresolved generic parameter")
 
-proc isTrival(s: PSym): bool {.inline.} =
+proc isTrival*(s: PSym): bool {.inline.} =
   s == nil or (s.ast != nil and s.ast[bodyPos].len == 0)
 
 proc createTypeBoundOps(g: ModuleGraph; c: PContext; orig: PType; info: TLineInfo;
@@ -1261,7 +1267,7 @@ 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] = default(array[attachedWasMoved..attachedTrace, bool])
+  var generics: array[attachedWasMoved..attachedTrace, bool]
   for k in attachedWasMoved..lastAttached:
     generics[k] = getAttachedOp(g, canon, k) != nil
     if not generics[k]:

compiler/liftlocals.nim

@@ -49,7 +49,6 @@ proc liftLocals(n: PNode; i: int; c: var Ctx) =
       liftLocals(it, i, c)
 
 proc lookupParam(params, dest: PNode): PSym =
-  result = nil
   if dest.kind != nkIdent: return nil
   for i in 1..<params.len:
     if params[i].kind == nkSym and params[i].sym.name.id == dest.ident.id:

compiler/lineinfos.nim

@@ -7,8 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
-## This module contains the `TMsgKind` enum as well as the
-## `TLineInfo` object.
+## This module contains the ``TMsgKind`` enum as well as the
+## ``TLineInfo`` object.
 
 import ropes, tables, pathutils, hashes
 
@@ -91,6 +91,7 @@ type
     warnStmtListLambda = "StmtListLambda",
     warnBareExcept = "BareExcept",
     warnImplicitDefaultValue = "ImplicitDefaultValue",
+    warnGenericsIgnoredInjection = "GenericsIgnoredInjection",
     warnUser = "User",
     # hints
     hintSuccess = "Success", hintSuccessX = "SuccessX",
@@ -108,6 +109,7 @@ type
     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",
+    warnGenericsIgnoredInjection: "$1",
     warnUser: "$1",
     hintSuccess: "operation successful: $#",
     # keep in sync with `testament.isSuccess`
@@ -231,6 +234,7 @@ const
     hintExtendedContext: "$1",
     hintMsgOrigin: "$1",
     hintDeclaredLoc: "$1",
+    hintUnknownHint: "unknown hint: $1"
   ]
 
 const
@@ -248,7 +252,6 @@ type
   TNoteKinds* = set[TNoteKind]
 
 proc computeNotesVerbosity(): array[0..3, TNoteKinds] =
-  result = default(array[0..3, TNoteKinds])
   result[3] = {low(TNoteKind)..high(TNoteKind)} - {warnObservableStores, warnResultUsed, warnAnyEnumConv, warnBareExcept}
   result[2] = result[3] - {hintStackTrace, hintExtendedContext, hintDeclaredLoc, hintProcessingStmt}
   result[1] = result[2] - {warnProveField, warnProveIndex,
@@ -311,7 +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, noreturn.} =
+proc raiseRecoverableError*(msg: string) {.noinline.} =
   raise newException(ERecoverableError, msg)
 
 const
@@ -342,8 +345,9 @@ type
 
 
 proc initMsgConfig*(): MsgConfig =
-  result = MsgConfig(msgContext: @[], lastError: unknownLineInfo,
-                     filenameToIndexTbl: initTable[string, FileIndex](),
-                     fileInfos: @[], errorOutputs: {eStdOut, eStdErr}
-  )
+  result.msgContext = @[]
+  result.lastError = unknownLineInfo
+  result.filenameToIndexTbl = initTable[string, FileIndex]()
+  result.fileInfos = @[]
+  result.errorOutputs = {eStdOut, eStdErr}
   result.filenameToIndexTbl["???"] = FileIndex(-1)

compiler/linter.nim

@@ -19,12 +19,10 @@ 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

@@ -40,22 +40,33 @@ type
 
   PLLStream* = ref TLLStream
 
-proc llStreamOpen*(data: sink string): PLLStream =
-  PLLStream(kind: llsString, s: data)
+proc llStreamOpen*(data: string): PLLStream =
+  new(result)
+  result.s = data
+  result.kind = llsString
 
 proc llStreamOpen*(f: File): PLLStream =
-  PLLStream(kind: llsFile, f: f)
+  new(result)
+  result.f = f
+  result.kind = llsFile
 
 proc llStreamOpen*(filename: AbsoluteFile, mode: FileMode): PLLStream =
-  result = PLLStream(kind: llsFile)
+  new(result)
+  result.kind = llsFile
   if not open(result.f, filename.string, mode): result = nil
 
 proc llStreamOpen*(): PLLStream =
-  PLLStream(kind: llsNone)
+  new(result)
+  result.kind = llsNone
 
 proc llReadFromStdin(s: PLLStream, buf: pointer, bufLen: int): int
 proc llStreamOpenStdIn*(r: TLLRepl = llReadFromStdin, onPrompt: OnPrompt = nil): PLLStream =
-  PLLStream(kind: llsStdIn, s: "", lineOffset: -1, repl: r, onPrompt: onPrompt)
+  new(result)
+  result.kind = llsStdIn
+  result.s = ""
+  result.lineOffset = -1
+  result.repl = r
+  result.onPrompt = onPrompt
 
 proc llStreamClose*(s: PLLStream) =
   case s.kind
@@ -78,8 +89,6 @@ 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 = {'+', '-', '*', '/', '\\', '<', '>', '!', '?', '^',
@@ -95,7 +104,6 @@ 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

@@ -72,7 +72,7 @@ proc addUniqueSym*(scope: PScope, s: PSym): PSym =
 
 proc openScope*(c: PContext): PScope {.discardable.} =
   result = PScope(parent: c.currentScope,
-                  symbols: initStrTable(),
+                  symbols: newStrTable(),
                   depthLevel: c.scopeDepth + 1)
   c.currentScope = result
 
@@ -254,6 +254,41 @@ proc searchInScopesFilterBy*(c: PContext, s: PIdent, filter: TSymKinds): seq[PSy
         if s.kind in filter:
           result.add s
 
+proc isAmbiguous*(c: PContext, s: PIdent, filter: TSymKinds, sym: var PSym): bool =
+  result = false
+  block outer:
+    for scope in allScopes(c.currentScope):
+      var ti: TIdentIter
+      var candidate = initIdentIter(ti, scope.symbols, s)
+      var scopeHasCandidate = false
+      while candidate != nil:
+        if candidate.kind in filter:
+          if scopeHasCandidate:
+            # 2 candidates in same scope, ambiguous
+            return true
+          else:
+            scopeHasCandidate = true
+            sym = candidate
+        candidate = nextIdentIter(ti, scope.symbols)
+      if scopeHasCandidate:
+        # scope had a candidate but wasn't ambiguous
+        return false
+
+  var importsHaveCandidate = false
+  var marked = initIntSet()
+  for im in c.imports.mitems:
+    for s in symbols(im, marked, s, c.graph):
+      if s.kind in filter:
+        if importsHaveCandidate:
+          # 2 candidates among imports, ambiguous
+          return true
+        else:
+          importsHaveCandidate = true
+          sym = s
+  if importsHaveCandidate:
+    # imports had a candidate but wasn't ambiguous
+    return false
+
 proc errorSym*(c: PContext, n: PNode): PSym =
   ## creates an error symbol to avoid cascading errors (for IDE support)
   var m = n
@@ -298,7 +333,7 @@ proc ensureNoMissingOrUnusedSymbols(c: PContext; scope: PScope) =
   var it: TTabIter
   var s = initTabIter(it, scope.symbols)
   var missingImpls = 0
-  var unusedSyms: seq[tuple[sym: PSym, key: string]] = @[]
+  var unusedSyms: seq[tuple[sym: PSym, key: string]]
   while s != nil:
     if sfForward in s.flags and s.kind notin {skType, skModule}:
       # too many 'implementation of X' errors are annoying
@@ -404,7 +439,7 @@ proc openShadowScope*(c: PContext) =
   ## opens a shadow scope, just like any other scope except the depth is the
   ## same as the parent -- see `isShadowScope`.
   c.currentScope = PScope(parent: c.currentScope,
-                          symbols: initStrTable(),
+                          symbols: newStrTable(),
                           depthLevel: c.scopeDepth)
 
 proc closeShadowScope*(c: PContext) =
@@ -458,7 +493,7 @@ proc fixSpelling(c: PContext, n: PNode, ident: PIdent, result: var string) =
   for (sym, depth, isLocal) in allSyms(c):
     let depth = -depth - 1
     let dist = editDistance(name0, sym.name.s.nimIdentNormalize)
-    var msg: string = ""
+    var msg: string
     msg.add "\n ($1, $2): '$3'" % [$dist, $depth, sym.name.s]
     list.push SpellCandidate(dist: dist, depth: depth, msg: msg, sym: sym)
 
@@ -488,7 +523,6 @@ 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"
@@ -532,7 +566,11 @@ proc errorUndeclaredIdentifier*(c: PContext; info: TLineInfo; name: string, extr
   if name == "_":
     err = "the special identifier '_' is ignored in declarations and cannot be used"
   else:
-    err = "undeclared identifier: '" & name & "'" & extra
+    err = "undeclared identifier: '" & name & "'"
+    if "`gensym" in name:
+      err.add "; if declared in a template, this identifier may be inconsistently marked inject or gensym"
+    if extra.len != 0:
+      err.add extra
     if c.recursiveDep.len > 0:
       err.add "\nThis might be caused by a recursive module dependency:\n"
       err.add c.recursiveDep
@@ -587,8 +625,6 @@ 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:
@@ -644,7 +680,6 @@ 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
@@ -668,7 +703,6 @@ 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:
@@ -698,7 +732,7 @@ proc initOverloadIter*(o: var TOverloadIter, c: PContext, n: PNode): PSym =
     o.symChoiceIndex = 1
     o.marked = initIntSet()
     incl(o.marked, result.id)
-  else: result = nil
+  else: discard
   when false:
     if result != nil and result.kind == skStub: loadStub(result)
 
@@ -713,7 +747,6 @@ 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
@@ -726,7 +759,6 @@ 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)
@@ -789,8 +821,6 @@ 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)
@@ -814,16 +844,13 @@ 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 =
-  result = nil
-  var o: TOverloadIter = default(TOverloadIter)
+  var o: 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 :-(

compiler/magicsys.nim

@@ -30,7 +30,6 @@ proc getSysSym*(g: ModuleGraph; info: TLineInfo; name: string): PSym =
     result.typ = newType(tyError, nextTypeId(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:
@@ -81,8 +80,8 @@ proc getSysType*(g: ModuleGraph; info: TLineInfo; kind: TTypeKind): PType =
 
 proc resetSysTypes*(g: ModuleGraph) =
   g.systemModule = nil
-  g.compilerprocs = initStrTable()
-  g.exposed = initStrTable()
+  initStrTable(g.compilerprocs)
+  initStrTable(g.exposed)
   for i in low(g.sysTypes)..high(g.sysTypes):
     g.sysTypes[i] = nil
 
@@ -100,7 +99,7 @@ proc skipIntLit*(t: PType; id: IdGenerator): PType {.inline.} =
 
 proc addSonSkipIntLit*(father, son: PType; id: IdGenerator) =
   let s = son.skipIntLit(id)
-  father.add(s)
+  father.sons.add(s)
   propagateToOwner(father, s)
 
 proc getCompilerProc*(g: ModuleGraph; name: string): PSym =
@@ -124,7 +123,7 @@ proc registerNimScriptSymbol*(g: ModuleGraph; s: PSym) =
 proc getNimScriptSymbol*(g: ModuleGraph; name: string): PSym =
   strTableGet(g.exposed, getIdent(g.cache, name))
 
-proc resetNimScriptSymbols*(g: ModuleGraph) = g.exposed = initStrTable()
+proc resetNimScriptSymbols*(g: ModuleGraph) = initStrTable(g.exposed)
 
 proc getMagicEqSymForType*(g: ModuleGraph; t: PType; info: TLineInfo): PSym =
   case t.kind
@@ -146,7 +145,6 @@ proc getMagicEqSymForType*(g: ModuleGraph; t: PType; info: TLineInfo): PSym =
   of tyProc:
     result = getSysMagic(g, info, "==", mEqProc)
   else:
-    result = nil
     globalError(g.config, info,
       "can't find magic equals operator for type kind " & $t.kind)
 

compiler/main.nim

@@ -56,7 +56,7 @@ 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 = default(File)
+  var fl: File
   var prevset = initCountTable[string]()
   if open(fl, fname.string, fmRead):
     for line in fl.lines: prevset.inc(line)
@@ -115,7 +115,7 @@ when not defined(leanCompiler):
       setPipeLinePass(graph, Docgen2JsonPass)
     of HtmlExt:
       setPipeLinePass(graph, Docgen2Pass)
-    else: raiseAssert $ext
+    else: doAssert false, $ext
     compilePipelineProject(graph)
 
 proc commandCompileToC(graph: ModuleGraph) =
@@ -151,7 +151,7 @@ proc commandCompileToC(graph: ModuleGraph) =
     extccomp.callCCompiler(conf)
     # for now we do not support writing out a .json file with the build instructions when HCR is on
     if not conf.hcrOn:
-      extccomp.writeJsonBuildInstructions(conf)
+      extccomp.writeJsonBuildInstructions(conf, graph.cachedFiles)
     if optGenScript in graph.config.globalOptions:
       writeDepsFile(graph)
     if optGenCDeps in graph.config.globalOptions:
@@ -196,7 +196,7 @@ proc commandScan(cache: IdentCache, config: ConfigRef) =
   if stream != nil:
     var
       L: Lexer
-      tok: Token = default(Token)
+      tok: Token
     initToken(tok)
     openLexer(L, f, stream, cache, config)
     while true:
@@ -267,7 +267,7 @@ proc mainCommand*(graph: ModuleGraph) =
         # and it has added this define implictly, so we must undo that here.
         # A better solution might be to fix system.nim
         undefSymbol(conf.symbols, "useNimRtl")
-    of backendInvalid: raiseAssert "unreachable"
+    of backendInvalid: doAssert false
 
   proc compileToBackend() =
     customizeForBackend(conf.backend)
@@ -277,7 +277,7 @@ proc mainCommand*(graph: ModuleGraph) =
     of backendCpp: commandCompileToC(graph)
     of backendObjc: commandCompileToC(graph)
     of backendJs: commandCompileToJS(graph)
-    of backendInvalid: raiseAssert "unreachable"
+    of backendInvalid: doAssert false
 
   template docLikeCmd(body) =
     when defined(leanCompiler):

compiler/modulegraphs.nim

@@ -11,7 +11,7 @@
 ## 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, strtabs]
 import ../dist/checksums/src/checksums/md5
 import ast, astalgo, options, lineinfos,idents, btrees, ropes, msgs, pathutils, packages
 import ic / [packed_ast, ic]
@@ -57,6 +57,7 @@ type
   SymInfoPair* = object
     sym*: PSym
     info*: TLineInfo
+    isDecl*: bool
 
   PipelinePass* = enum
     NonePass
@@ -128,6 +129,8 @@ type
     idgen*: IdGenerator
     operators*: Operators
 
+    cachedFiles*: StringTableRef
+
   TPassContext* = object of RootObj # the pass's context
     idgen*: IdGenerator
   PPassContext* = ref TPassContext
@@ -142,7 +145,7 @@ type
                  isFrontend: bool]
 
 proc resetForBackend*(g: ModuleGraph) =
-  g.compilerprocs = initStrTable()
+  initStrTable(g.compilerprocs)
   g.typeInstCache.clear()
   g.procInstCache.clear()
   for a in mitems(g.attachedOps):
@@ -196,8 +199,8 @@ template semtabAll*(g: ModuleGraph, m: PSym): TStrTable =
   g.ifaces[m.position].interfHidden
 
 proc initStrTables*(g: ModuleGraph, m: PSym) =
-  semtab(g, m) = initStrTable()
-  semtabAll(g, m) = initStrTable()
+  initStrTable(semtab(g, m))
+  initStrTable(semtabAll(g, m))
 
 proc strTableAdds*(g: ModuleGraph, m: PSym, s: PSym) =
   strTableAdd(semtab(g, m), s)
@@ -368,7 +371,6 @@ 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:
@@ -459,7 +461,7 @@ 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)
-  result.packageSyms = initStrTable()
+  initStrTable(result.packageSyms)
   result.deps = initIntSet()
   result.importDeps = initTable[FileIndex, seq[FileIndex]]()
   result.ifaces = @[]
@@ -469,9 +471,9 @@ proc initModuleGraphFields(result: ModuleGraph) =
   result.suggestSymbols = initTable[FileIndex, seq[SymInfoPair]]()
   result.suggestErrors = initTable[FileIndex, seq[Suggest]]()
   result.methods = @[]
-  result.compilerprocs = initStrTable()
-  result.exposed = initStrTable()
-  result.packageTypes = initStrTable()
+  initStrTable(result.compilerprocs)
+  initStrTable(result.exposed)
+  initStrTable(result.packageTypes)
   result.emptyNode = newNode(nkEmpty)
   result.cacheSeqs = initTable[string, PNode]()
   result.cacheCounters = initTable[string, BiggestInt]()
@@ -480,6 +482,7 @@ proc initModuleGraphFields(result: ModuleGraph) =
   result.symBodyHashes = initTable[int, SigHash]()
   result.operators = initOperators(result)
   result.emittedTypeInfo = initTable[string, FileIndex]()
+  result.cachedFiles = newStringTable()
 
 proc newModuleGraph*(cache: IdentCache; config: ConfigRef): ModuleGraph =
   result = ModuleGraph()
@@ -488,7 +491,7 @@ proc newModuleGraph*(cache: IdentCache; config: ConfigRef): ModuleGraph =
   initModuleGraphFields(result)
 
 proc resetAllModules*(g: ModuleGraph) =
-  g.packageSyms = initStrTable()
+  initStrTable(g.packageSyms)
   g.deps = initIntSet()
   g.ifaces = @[]
   g.importStack = @[]
@@ -496,12 +499,11 @@ proc resetAllModules*(g: ModuleGraph) =
   g.usageSym = nil
   g.owners = @[]
   g.methods = @[]
-  g.compilerprocs = initStrTable()
-  g.exposed = initStrTable()
+  initStrTable(g.compilerprocs)
+  initStrTable(g.exposed)
   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
@@ -607,7 +609,6 @@ 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:
@@ -615,7 +616,6 @@ 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
@@ -637,8 +637,6 @@ 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

@@ -36,11 +36,18 @@ proc getModuleName*(conf: ConfigRef; n: PNode): string =
           localError(n.info, "only '/' supported with $package notation")
           result = ""
     else:
-      let modname = getModuleName(conf, n[2])
-      # hacky way to implement 'x / y /../ z':
-      result = getModuleName(conf, n1)
-      result.add renderTree(n0, {renderNoComments}).replace(" ")
-      result.add modname
+      if n0.kind in nkIdentKinds:
+        let ident = n0.getPIdent
+        if ident != nil and ident.s[0] == '/':
+          let modname = getModuleName(conf, n[2])
+          # hacky way to implement 'x / y /../ z':
+          result = getModuleName(conf, n1)
+          result.add renderTree(n0, {renderNoComments}).replace(" ")
+          result.add modname
+        else:
+          result = ""
+      else:
+        result = ""
   of nkPrefix:
     when false:
       if n[0].kind == nkIdent and n[0].ident.s == "$":

compiler/modules.nim

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

compiler/msgs.nim

@@ -294,11 +294,9 @@ 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)
@@ -410,7 +408,7 @@ proc getMessageStr(msg: TMsgKind, arg: string): string = msgKindToString(msg) %
 type TErrorHandling* = enum doNothing, doAbort, doRaise
 
 proc log*(s: string) =
-  var f: File = default(File)
+  var f: File
   if open(f, getHomeDir() / "nimsuggest.log", fmAppend):
     f.writeLine(s)
     close(f)
@@ -431,7 +429,8 @@ To create a stacktrace, rerun compilation with './koch temp $1 <file>', see $2 f
 proc handleError(conf: ConfigRef; msg: TMsgKind, eh: TErrorHandling, s: string, ignoreMsg: bool) =
   if msg in fatalMsgs:
     if conf.cmd == cmdIdeTools: log(s)
-    quit(conf, msg)
+    if conf.cmd != cmdIdeTools or msg != errFatal:
+      quit(conf, msg)
   if msg >= errMin and msg <= errMax or
       (msg in warnMin..hintMax and msg in conf.warningAsErrors and not ignoreMsg):
     inc(conf.errorCounter)
@@ -439,7 +438,11 @@ proc handleError(conf: ConfigRef; msg: TMsgKind, eh: TErrorHandling, s: string,
     if conf.errorCounter >= conf.errorMax:
       # only really quit when we're not in the new 'nim check --def' mode:
       if conf.ideCmd == ideNone:
-        quit(conf, msg)
+        when defined(nimsuggest):
+          #we need to inform the user that something went wrong when initializing NimSuggest
+          raiseRecoverableError(s)
+        else:
+          quit(conf, msg)
     elif eh == doAbort and conf.cmd != cmdIdeTools:
       quit(conf, msg)
     elif eh == doRaise:
@@ -504,8 +507,6 @@ 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
@@ -557,9 +558,10 @@ proc liMessage*(conf: ConfigRef; info: TLineInfo, msg: TMsgKind, arg: string,
     ignoreMsg = not conf.hasHint(msg)
     if not ignoreMsg and msg in conf.warningAsErrors:
       title = ErrorTitle
+      color = ErrorColor
     else:
       title = HintTitle
-    color = HintColor
+      color = HintColor
     inc(conf.hintCounter)
 
   let s = if isRaw: arg else: getMessageStr(msg, arg)
@@ -647,13 +649,16 @@ template lintReport*(conf: ConfigRef; info: TLineInfo, beau, got: string, extraM
   let msg = if optStyleError in conf.globalOptions: errGenerated else: hintName
   liMessage(conf, info, msg, m, doNothing, instLoc())
 
-proc quotedFilename*(conf: ConfigRef; i: TLineInfo): Rope =
-  if i.fileIndex.int32 < 0:
+proc quotedFilename*(conf: ConfigRef; fi: FileIndex): Rope =
+  if fi.int32 < 0:
     result = makeCString "???"
   elif optExcessiveStackTrace in conf.globalOptions:
-    result = conf.m.fileInfos[i.fileIndex.int32].quotedFullName
+    result = conf.m.fileInfos[fi.int32].quotedFullName
   else:
-    result = conf.m.fileInfos[i.fileIndex.int32].quotedName
+    result = conf.m.fileInfos[fi.int32].quotedName
+
+proc quotedFilename*(conf: ConfigRef; i: TLineInfo): Rope =
+  quotedFilename(conf, i.fileIndex)
 
 template listMsg(title, r) =
   msgWriteln(conf, title, {msgNoUnitSep})

compiler/nilcheck.nim

@@ -309,7 +309,6 @@ 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:
@@ -417,7 +416,7 @@ proc moveOut(ctx: NilCheckerContext, map: NilMap, target: PNode) =
   if targetSetIndex != noSetIndex:
     var targetSet = map.sets[targetSetIndex]
     if targetSet.len > 1:
-      var other: ExprIndex = default(ExprIndex)
+      var other: ExprIndex
 
       for element in targetSet:
         if element.ExprIndex != targetIndex:
@@ -562,7 +561,7 @@ 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 = ""
@@ -766,7 +765,7 @@ 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 = nil
+  var afterLayer: NilMap
   # the result nilability for expressions
   var nilability = Safe
 
@@ -863,10 +862,9 @@ 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 = nil
-    var mapR: NilMap = nil
+    var mapL: NilMap
+    var mapR: NilMap
     if n[0].sym.magic notin {mAnd, mEqRef}:
       mapL = checkCondition(n[1], ctx, map, false, false)
       mapR = checkCondition(n[2], ctx, map, false, false)
@@ -949,7 +947,7 @@ proc checkCase(n, ctx, map): Check =
   let base = n[0]
   result.map = map.copyMap()
   result.nilability = Safe
-  var a: PNode = nil
+  var a: PNode
   for child in n:
     case child.kind:
     of nkOfBranch:
@@ -1224,7 +1222,7 @@ 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:
@@ -1335,7 +1333,7 @@ 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 = initIntSet() # set[ExprIndex]
+  var emptySet: IntSet # set[ExprIndex]
   ctx.dependants = SeqOfDistinct[ExprIndex, IntSet](@[emptySet])
   for i, arg in s.typ.n.sons:
     if i > 0:

compiler/nim.cfg

@@ -43,11 +43,3 @@ define:useStdoutAsStdmsg
 @if nimHasWarnBareExcept:
   warningAserror[BareExcept]:on
 @end
-
-
-@if nimUseStrictDefs:
-  experimental:strictDefs
-  warningAsError[Uninit]:on
-  warningAsError[ProveInit]:on
-@end
-

compiler/nim.nim

@@ -91,9 +91,6 @@ proc getNimRunExe(conf: ConfigRef): string =
   if conf.isDefined("mingw"):
     if conf.isDefined("i386"): result = "wine"
     elif conf.isDefined("amd64"): result = "wine64"
-    else: result = ""
-  else:
-    result = ""
 
 proc handleCmdLine(cache: IdentCache; conf: ConfigRef) =
   let self = NimProg(
@@ -140,7 +137,7 @@ 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: raiseAssert $conf.backend
+      else: doAssert false, $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

@@ -37,16 +37,11 @@ proc isSpecial(ver: Version): bool =
 
 proc isValidVersion(v: string): bool =
   if v.len > 0:
-    if v[0] in {'#'} + Digits:
-      result = true
-    else:
-      result = false
-  else:
-    result = false
+    if v[0] in {'#'} + Digits: return true
 
 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":
@@ -150,7 +145,7 @@ 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 = initTable[string, tuple[version, checksum: string]]()
+  var packages: PackageInfo
   var pos = dir.len-1
   if dir[pos] in {DirSep, AltSep}: inc(pos)
   for k,p in os.walkDir(dir):

compiler/nimconf.nim

@@ -214,7 +214,7 @@ proc parseAssignment(L: var Lexer, tok: var Token;
 proc readConfigFile*(filename: AbsoluteFile; cache: IdentCache;
                     config: ConfigRef): bool =
   var
-    L: Lexer = default(Lexer)
+    L: Lexer
     tok: Token
     stream: PLLStream
   stream = llStreamOpen(filename, fmRead)
@@ -228,8 +228,6 @@ proc readConfigFile*(filename: AbsoluteFile; cache: IdentCache;
     if condStack.len > 0: lexMessage(L, errGenerated, "expected @end")
     closeLexer(L)
     return true
-  else:
-    result = false
 
 proc getUserConfigPath*(filename: RelativeFile): AbsoluteFile =
   result = getConfigDir().AbsoluteDir / RelativeDir"nim" / filename
@@ -252,7 +250,7 @@ proc loadConfigs*(cfg: RelativeFile; cache: IdentCache; conf: ConfigRef; idgen:
 
   template runNimScriptIfExists(path: AbsoluteFile, isMain = false) =
     let p = path # eval once
-    var s: PLLStream = nil
+    var s: PLLStream
     if isMain and optWasNimscript in conf.globalOptions:
       if conf.projectIsStdin: s = stdin.llStreamOpen
       elif conf.projectIsCmd: s = llStreamOpen(conf.cmdInput)

compiler/nimsets.nim

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

compiler/optimizer.nim

@@ -279,7 +279,7 @@ proc optimize*(n: PNode): PNode =
 
     Now assume 'use' raises, then we shouldn't do the 'wasMoved(s)'
   ]#
-  var c: Con = Con()
+  var c: Con
   var b: BasicBlock
   analyse(c, b, n)
   if c.somethingTodo:

compiler/options.nim

@@ -195,7 +195,7 @@ type
   IdeCmd* = enum
     ideNone, ideSug, ideCon, ideDef, ideUse, ideDus, ideChk, ideChkFile, ideMod,
     ideHighlight, ideOutline, ideKnown, ideMsg, ideProject, ideGlobalSymbols,
-    ideRecompile, ideChanged, ideType, ideDeclaration, ideExpand
+    ideRecompile, ideChanged, ideType, ideDeclaration, ideExpand, ideInlayHints
 
   Feature* = enum  ## experimental features; DO NOT RENAME THESE!
     dotOperators,
@@ -209,7 +209,7 @@ type
     codeReordering,
     compiletimeFFI,
       ## This requires building nim with `-d:nimHasLibFFI`
-      ## which itself requires `koch installdeps libffi`, see #10150
+      ## which itself requires `nimble install libffi`, see #10150
       ## Note: this feature can't be localized with {.push.}
     vmopsDanger,
     strictFuncs,
@@ -221,8 +221,7 @@ type
     flexibleOptionalParams,
     strictDefs,
     strictCaseObjects,
-    inferGenericTypes
-    noforwardDecl
+    genericsOpenSym
 
   LegacyFeature* = enum
     allowSemcheckedAstModification,
@@ -282,9 +281,24 @@ type
     version*: int
     endLine*: uint16
     endCol*: int
+    inlayHintInfo*: SuggestInlayHint
 
   Suggestions* = seq[Suggest]
 
+  SuggestInlayHintKind* = enum
+    sihkType = "Type",
+    sihkParameter = "Parameter"
+
+  SuggestInlayHint* = ref object
+    kind*: SuggestInlayHintKind
+    line*: int                   # Starts at 1
+    column*: int                 # Starts at 0
+    label*: string
+    paddingLeft*: bool
+    paddingRight*: bool
+    allowInsert*: bool
+    tooltip*: string
+
   ProfileInfo* = object
     time*: float
     count*: int
@@ -419,10 +433,11 @@ type
     expandNodeResult*: string
     expandPosition*: TLineInfo
 
+    clientProcessId*: int
+
 
 proc parseNimVersion*(a: string): NimVer =
   # could be moved somewhere reusable
-  result = default(NimVer)
   if a.len > 0:
     let b = a.split(".")
     assert b.len == 3, a
@@ -659,12 +674,12 @@ proc isDefined*(conf: ConfigRef; symbol: string): bool =
     of "nimrawsetjmp":
       result = conf.target.targetOS in {osSolaris, osNetbsd, osFreebsd, osOpenbsd,
                             osDragonfly, osMacosx}
-    else: result = false
+    else: discard
 
 template quitOrRaise*(conf: ConfigRef, msg = "") =
   # xxx in future work, consider whether to also intercept `msgQuit` calls
   if conf.isDefined("nimDebug"):
-    raiseAssert msg
+    doAssert false, msg
   else:
     quit(msg) # quits with QuitFailure
 
@@ -885,7 +900,6 @@ const
   stdPrefix = "std/"
 
 proc getRelativePathFromConfigPath*(conf: ConfigRef; f: AbsoluteFile, isTitle = false): RelativeFile =
-  result = RelativeFile("")
   let f = $f
   if isTitle:
     for dir in stdlibDirs:
@@ -921,7 +935,6 @@ proc findModule*(conf: ConfigRef; modulename, currentModule: string): AbsoluteFi
     result = findFile(conf, m.substr(pkgPrefix.len), suppressStdlib = true)
   else:
     if m.startsWith(stdPrefix):
-      result = AbsoluteFile("")
       let stripped = m.substr(stdPrefix.len)
       for candidate in stdlibDirs:
         let path = (conf.libpath.string / candidate / stripped)
@@ -1062,6 +1075,7 @@ proc `$`*(c: IdeCmd): string =
   of ideRecompile: "recompile"
   of ideChanged: "changed"
   of ideType: "type"
+  of ideInlayHints: "inlayHints"
 
 proc floatInt64Align*(conf: ConfigRef): int16 =
   ## Returns either 4 or 8 depending on reasons.

compiler/packagehandling.nim

@@ -17,7 +17,6 @@ iterator myParentDirs(p: string): string =
 
 proc getNimbleFile*(conf: ConfigRef; path: string): string =
   ## returns absolute path to nimble file, e.g.: /pathto/cligen.nimble
-  result = ""
   var parents = 0
   block packageSearch:
     for d in myParentDirs(path):

compiler/parampatterns.nim

@@ -184,7 +184,6 @@ type
     arStrange                 # it is a strange beast like 'typedesc[var T]'
 
 proc exprRoot*(n: PNode; allowCalls = true): PSym =
-  result = nil
   var it = n
   while true:
     case it.kind

compiler/parser.nim

@@ -1177,7 +1177,6 @@ proc optPragmas(p: var Parser): PNode =
 
 proc parseDoBlock(p: var Parser; info: TLineInfo): PNode =
   #| doBlock = 'do' paramListArrow pragma? colcom stmt
-  result = nil
   var params = parseParamList(p, retColon=false)
   let pragmas = optPragmas(p)
   colcom(p, result)
@@ -1431,7 +1430,7 @@ proc parseTypeDesc(p: var Parser, fullExpr = false): PNode =
       result = newNodeP(nkObjectTy, p)
       getTok(p)
     of tkConcept:
-      result = nil
+      result = p.emptyNode
       parMessage(p, "the 'concept' keyword is only valid in 'type' sections")
     of tkVar: result = parseTypeDescKAux(p, nkVarTy, pmTypeDesc)
     of tkOut: result = parseTypeDescKAux(p, nkOutTy, pmTypeDesc)
@@ -2287,7 +2286,7 @@ proc parseTypeDef(p: var Parser): PNode =
   setEndInfo()
 
 proc parseVarTuple(p: var Parser): PNode =
-  #| varTupleLhs = '(' optInd (identWithPragma / varTupleLhs) ^+ comma optPar ')'
+  #| varTupleLhs = '(' optInd (identWithPragma / varTupleLhs) ^+ comma optPar ')' (':' optInd typeDescExpr)?
   #| varTuple = varTupleLhs '=' optInd expr
   result = newNodeP(nkVarTuple, p)
   getTok(p)                   # skip '('
@@ -2304,9 +2303,14 @@ proc parseVarTuple(p: var Parser): PNode =
     if p.tok.tokType != tkComma: break
     getTok(p)
     skipComment(p, a)
-  result.add(p.emptyNode)         # no type desc
   optPar(p)
   eat(p, tkParRi)
+  if p.tok.tokType == tkColon:
+    getTok(p)
+    optInd(p, result)
+    result.add(parseTypeDesc(p, fullExpr = true))
+  else:
+    result.add(p.emptyNode)         # no type desc
   setEndInfo()
 
 proc parseVariable(p: var Parser): PNode =
@@ -2513,22 +2517,6 @@ proc parseStmt(p: var Parser): PNode =
           if err and p.tok.tokType == tkEof: break
   setEndInfo()
 
-proc parseAll(p: var Parser): PNode =
-  ## Parses the rest of the input stream held by the parser into a PNode.
-  result = newNodeP(nkStmtList, p)
-  while p.tok.tokType != tkEof:
-    p.hasProgress = false
-    var a = complexOrSimpleStmt(p)
-    if a.kind != nkEmpty and p.hasProgress:
-      result.add(a)
-    else:
-      parMessage(p, errExprExpected, p.tok)
-      # bugfix: consume a token here to prevent an endless loop:
-      getTok(p)
-    if p.tok.indent != 0:
-      parMessage(p, errInvalidIndentation)
-  setEndInfo()
-
 proc checkFirstLineIndentation*(p: var Parser) =
   if p.tok.indent != 0 and tsLeading in p.tok.spacing:
     parMessage(p, errInvalidIndentation)
@@ -2563,6 +2551,16 @@ proc parseTopLevelStmt(p: var Parser): PNode =
       break
   setEndInfo()
 
+proc parseAll*(p: var Parser): PNode =
+  ## Parses the rest of the input stream held by the parser into a PNode.
+  result = newNodeP(nkStmtList, p)
+  while true:
+    let nextStmt = p.parseTopLevelStmt()
+    if nextStmt.kind == nkEmpty:
+      break
+    result &= nextStmt
+  setEndInfo()
+
 proc parseString*(s: string; cache: IdentCache; config: ConfigRef;
                   filename: string = ""; line: int = 0;
                   errorHandler: ErrorHandler = nil): PNode =

compiler/patterns.nim

@@ -29,8 +29,6 @@ type
 proc getLazy(c: PPatternContext, sym: PSym): PNode =
   if c.mappingIsFull:
     result = c.mapping[sym.position]
-  else:
-    result = nil
 
 proc putLazy(c: PPatternContext, sym: PSym, n: PNode) =
   if not c.mappingIsFull:
@@ -67,21 +65,14 @@ proc sameTrees*(a, b: PNode): bool =
         for i in 0..<a.len:
           if not sameTrees(a[i], b[i]): return
         result = true
-      else:
-        result = false
-  else:
-    result = false
 
 proc inSymChoice(sc, x: PNode): bool =
   if sc.kind == nkClosedSymChoice:
-    result = false
     for i in 0..<sc.len:
       if sc[i].sym == x.sym: return true
   elif sc.kind == nkOpenSymChoice:
     # same name suffices for open sym choices!
     result = sc[0].sym.name.id == x.sym.name.id
-  else:
-    result = false
 
 proc checkTypes(c: PPatternContext, p: PSym, n: PNode): bool =
   # check param constraints first here as this is quite optimized:
@@ -97,7 +88,6 @@ proc isPatternParam(c: PPatternContext, p: PNode): bool {.inline.} =
   result = p.kind == nkSym and p.sym.kind == skParam and p.sym.owner == c.owner
 
 proc matchChoice(c: PPatternContext, p, n: PNode): bool =
-  result = false
   for i in 1..<p.len:
     if matches(c, p[i], n): return true
 
@@ -109,8 +99,6 @@ proc bindOrCheck(c: PPatternContext, param: PSym, n: PNode): bool =
   elif n.kind == nkArgList or checkTypes(c, param, n):
     putLazy(c, param, n)
     result = true
-  else:
-    result = false
 
 proc gather(c: PPatternContext, param: PSym, n: PNode) =
   var pp = getLazy(c, param)
@@ -144,10 +132,6 @@ proc matchNested(c: PPatternContext, p, n: PNode, rpn: bool): bool =
     var arglist = newNodeI(nkArgList, n.info)
     if matchStarAux(c, p, n, arglist, rpn):
       result = bindOrCheck(c, p[2].sym, arglist)
-    else:
-      result = false
-  else:
-    result = false
 
 proc matches(c: PPatternContext, p, n: PNode): bool =
   let n = skipHidden(n)
@@ -163,7 +147,6 @@ proc matches(c: PPatternContext, p, n: PNode): bool =
     # try both:
     if p.kind == nkSym: result = p.sym == n.sym
     elif matches(c, p, n.sym.astdef): result = true
-    else: result = false
   elif p.kind == nkPattern:
     # pattern operators: | *
     let opr = p[0].ident.s
@@ -172,9 +155,7 @@ proc matches(c: PPatternContext, p, n: PNode): bool =
     of "*": result = matchNested(c, p, n, rpn=false)
     of "**": result = matchNested(c, p, n, rpn=true)
     of "~": result = not matches(c, p[1], n)
-    else:
-      result = false
-      doAssert(false, "invalid pattern")
+    else: doAssert(false, "invalid pattern")
     # template {add(a, `&` * b)}(a: string{noalias}, b: varargs[string]) =
     #   a.add(b)
   elif p.kind == nkCurlyExpr:
@@ -182,14 +163,10 @@ proc matches(c: PPatternContext, p, n: PNode): bool =
       if matches(c, p[0], n):
         gather(c, p[1][1].sym, n)
         result = true
-      else:
-        result = false
     else:
       assert isPatternParam(c, p[1])
       if matches(c, p[0], n):
         result = bindOrCheck(c, p[1].sym, n)
-      else:
-        result = false
   elif sameKinds(p, n):
     case p.kind
     of nkSym: result = p.sym == n.sym
@@ -202,7 +179,6 @@ proc matches(c: PPatternContext, p, n: PNode): bool =
     else:
       # special rule for p(X) ~ f(...); this also works for stuff like
       # partial case statements, etc! - Not really ... :-/
-      result = false
       let v = lastSon(p)
       if isPatternParam(c, v) and v.sym.typ.kind == tyVarargs:
         var arglist: PNode
@@ -231,8 +207,6 @@ proc matches(c: PPatternContext, p, n: PNode): bool =
         for i in 0..<p.len:
           if not matches(c, p[i], n[i]): return
         result = true
-  else:
-    result = false
 
 proc matchStmtList(c: PPatternContext, p, n: PNode): PNode =
   proc matchRange(c: PPatternContext, p, n: PNode, i: int): bool =
@@ -245,7 +219,6 @@ proc matchStmtList(c: PPatternContext, p, n: PNode): PNode =
     result = true
 
   if p.kind == nkStmtList and n.kind == p.kind and p.len < n.len:
-    result = nil
     let n = flattenStmts(n)
     # no need to flatten 'p' here as that has already been done
     for i in 0..n.len - p.len:
@@ -258,11 +231,8 @@ proc matchStmtList(c: PPatternContext, p, n: PNode): PNode =
         break
   elif matches(c, p, n):
     result = n
-  else:
-    result = nil
 
 proc aliasAnalysisRequested(params: PNode): bool =
-  result = false
   if params.len >= 2:
     for i in 1..<params.len:
       let param = params[i].sym
@@ -288,11 +258,9 @@ proc applyRule*(c: PContext, s: PSym, n: PNode): PNode =
   result.add(newSymNode(s, n.info))
   let params = s.typ.n
   let requiresAA = aliasAnalysisRequested(params)
-  var args: PNode =
-    if requiresAA:
-      newNodeI(nkArgList, n.info)
-    else:
-      nil
+  var args: PNode
+  if requiresAA:
+    args = newNodeI(nkArgList, n.info)
   for i in 1..<params.len:
     let param = params[i].sym
     let x = getLazy(ctx, param)

compiler/pipelines.nim

@@ -5,10 +5,12 @@ import sem, cgen, modulegraphs, ast, llstream, parser, msgs,
 
 import pipelineutils
 
+import ../dist/checksums/src/checksums/sha1
+
 when not defined(leanCompiler):
   import jsgen, docgen2
 
-import std/[syncio, objectdollar, assertions, tables, strutils]
+import std/[syncio, objectdollar, assertions, tables, strutils, strtabs]
 import renderer
 import ic/replayer
 
@@ -25,8 +27,6 @@ proc processPipeline(graph: ModuleGraph; semNode: PNode; bModule: PPassContext):
   of JSgenPass:
     when not defined(leanCompiler):
       result = processJSCodeGen(bModule, semNode)
-    else:
-      result = nil
   of GenDependPass:
     result = addDotDependency(bModule, semNode)
   of SemPass:
@@ -34,17 +34,13 @@ proc processPipeline(graph: ModuleGraph; semNode: PNode; bModule: PPassContext):
   of Docgen2Pass, Docgen2TexPass:
     when not defined(leanCompiler):
       result = processNode(bModule, semNode)
-    else:
-      result = nil
   of Docgen2JsonPass:
     when not defined(leanCompiler):
       result = processNodeJson(bModule, semNode)
-    else:
-      result = nil
   of EvalPass, InterpreterPass:
     result = interpreterCode(bModule, semNode)
   of NonePass:
-    raiseAssert "use setPipeLinePass to set a proper PipelinePass"
+    doAssert false, "use setPipeLinePass to set a proper PipelinePass"
 
 proc processImplicitImports(graph: ModuleGraph; implicits: seq[string], nodeKind: TNodeKind,
                       m: PSym, ctx: PContext, bModule: PPassContext, idgen: IdGenerator,
@@ -81,9 +77,9 @@ proc prePass(c: PContext; n: PNode) =
             of nkStrLit, nkRStrLit, nkTripleStrLit:
               try:
                 let feature = parseEnum[Feature](name.strVal)
-                # if feature == codeReordering:
-                c.features.incl feature
-                c.module.flags.incl sfReorder
+                if feature == codeReordering:
+                  c.features.incl feature
+                  c.module.flags.incl sfReorder
               except ValueError:
                 discard
             else:
@@ -132,7 +128,8 @@ proc processPipelineModule*(graph: ModuleGraph; module: PSym; idgen: IdGenerator
     of SemPass:
       nil
     of NonePass:
-      raiseAssert "use setPipeLinePass to set a proper PipelinePass"
+      doAssert false, "use setPipeLinePass to set a proper PipelinePass"
+      nil
 
   if stream == nil:
     let filename = toFullPathConsiderDirty(graph.config, fileIdx)
@@ -206,7 +203,7 @@ proc processPipelineModule*(graph: ModuleGraph; module: PSym; idgen: IdGenerator
     when not defined(leanCompiler):
       discard closeJson(graph, bModule, finalNode)
   of NonePass:
-    raiseAssert "use setPipeLinePass to set a proper PipelinePass"
+    doAssert false, "use setPipeLinePass to set a proper PipelinePass"
 
   if graph.config.backend notin {backendC, backendCpp, backendObjc}:
     # We only write rod files here if no C-like backend is active.
@@ -222,15 +219,18 @@ proc compilePipelineModule*(graph: ModuleGraph; fileIdx: FileIndex; flags: TSymF
 
   template processModuleAux(moduleStatus) =
     onProcessing(graph, fileIdx, moduleStatus, fromModule = fromModule)
-    var s: PLLStream = nil
+    var s: PLLStream
     if sfMainModule in flags:
       if graph.config.projectIsStdin: s = stdin.llStreamOpen
       elif graph.config.projectIsCmd: s = llStreamOpen(graph.config.cmdInput)
     discard processPipelineModule(graph, result, idGeneratorFromModule(result), s)
   if result == nil:
-    var cachedModules: seq[FileIndex] = @[]
+    var cachedModules: seq[FileIndex]
     result = moduleFromRodFile(graph, fileIdx, cachedModules)
-    let filename = AbsoluteFile toFullPath(graph.config, fileIdx)
+    let path = toFullPath(graph.config, fileIdx)
+    let filename = AbsoluteFile path
+    if fileExists(filename): # it could be a stdinfile
+      graph.cachedFiles[path] = $secureHashFile(path)
     if result == nil:
       result = newModule(graph, fileIdx)
       result.flags.incl flags

compiler/platform.nim

@@ -277,7 +277,6 @@ proc nameToOS*(name: string): TSystemOS =
   result = osNone
 
 proc listOSnames*(): seq[string] =
-  result = @[]
   for i in succ(osNone)..high(TSystemOS):
     result.add OS[i].name
 
@@ -288,7 +287,6 @@ proc nameToCPU*(name: string): TSystemCPU =
   result = cpuNone
 
 proc listCPUnames*(): seq[string] =
-  result = @[]
   for i in succ(cpuNone)..high(TSystemCPU):
     result.add CPU[i].name
 

compiler/pragmas.nim

@@ -34,7 +34,7 @@ const
     wAsmNoStackFrame, wDiscardable, wNoInit, wCodegenDecl,
     wGensym, wInject, wRaises, wEffectsOf, wTags, wForbids, wLocks, wDelegator, wGcSafe,
     wConstructor, wLiftLocals, wStackTrace, wLineTrace, wNoDestroy,
-    wRequires, wEnsures, wEnforceNoRaises, wSystemRaisesDefect, wVirtual, wQuirky, wMember}
+    wRequires, wEnsures, wEnforceNoRaises, wSystemRaisesDefect, wVirtual, wQuirky}
   converterPragmas* = procPragmas
   methodPragmas* = procPragmas+{wBase}-{wImportCpp}
   templatePragmas* = {wDeprecated, wError, wGensym, wInject, wDirty,
@@ -94,7 +94,6 @@ const
   enumFieldPragmas* = {wDeprecated}
 
 proc getPragmaVal*(procAst: PNode; name: TSpecialWord): PNode =
-  result = nil
   let p = procAst[pragmasPos]
   if p.kind == nkEmpty: return nil
   for it in p:
@@ -140,9 +139,9 @@ proc pragmaEnsures(c: PContext, n: PNode) =
   else:
     openScope(c)
     let o = getCurrOwner(c)
-    if o.kind in routineKinds and o.typ != nil and o.typ[0] != nil:
+    if o.kind in routineKinds and o.typ != nil and o.typ.sons[0] != nil:
       var s = newSym(skResult, getIdent(c.cache, "result"), c.idgen, o, n.info)
-      s.typ = o.typ[0]
+      s.typ = o.typ.sons[0]
       incl(s.flags, sfUsed)
       addDecl(c, s)
     n[1] = c.semExpr(c, n[1])
@@ -232,7 +231,6 @@ proc expectStrLit(c: PContext, n: PNode): string =
   result = getStrLitNode(c, n).strVal
 
 proc expectIntLit(c: PContext, n: PNode): int =
-  result = 0
   if n.kind notin nkPragmaCallKinds or n.len != 2:
     localError(c.config, n.info, errIntLiteralExpected)
   else:
@@ -245,10 +243,10 @@ proc getOptionalStr(c: PContext, n: PNode, defaultStr: string): string =
   if n.kind in nkPragmaCallKinds: result = expectStrLit(c, n)
   else: result = defaultStr
 
-proc processVirtual(c: PContext, n: PNode, s: PSym, flag: TSymFlag) =
+proc processVirtual(c: PContext, n: PNode, s: PSym) =
   s.constraint = newEmptyStrNode(c, n, getOptionalStr(c, n, "$1"))
   s.constraint.strVal = s.constraint.strVal % s.name.s
-  s.flags.incl {flag, sfInfixCall, sfExportc, sfMangleCpp}
+  s.flags.incl {sfVirtual, sfInfixCall, sfExportc, sfMangleCpp}
 
   s.typ.callConv = ccNoConvention
   incl c.config.globalOptions, optMixedMode
@@ -278,7 +276,6 @@ proc wordToCallConv(sw: TSpecialWord): TCallingConvention =
   TCallingConvention(ord(ccNimCall) + ord(sw) - ord(wNimcall))
 
 proc isTurnedOn(c: PContext, n: PNode): bool =
-  result = false
   if n.kind in nkPragmaCallKinds and n.len == 2:
     let x = c.semConstBoolExpr(c, n[1])
     n[1] = x
@@ -333,7 +330,7 @@ proc expectDynlibNode(c: PContext, n: PNode): PNode =
     # {.dynlib: myGetProcAddr(...).}
     result = c.semExpr(c, n[1])
     if result.kind == nkSym and result.sym.kind == skConst:
-      result = result.sym.astdef # look it up
+      result = c.semConstExpr(c, result) # fold const
     if result.typ == nil or result.typ.kind notin {tyPointer, tyString, tyProc}:
       localError(c.config, n.info, errStringLiteralExpected)
       result = newEmptyStrNode(c, n)
@@ -471,6 +468,18 @@ proc processOption(c: PContext, n: PNode, resOptions: var TOptions) =
     # calling conventions (boring...):
     localError(c.config, n.info, "option expected")
 
+proc checkPushedPragma(c: PContext, n: PNode) =
+  let keyDeep = n.kind in nkPragmaCallKinds and n.len > 1
+  var key = if keyDeep: n[0] else: n
+  if key.kind in nkIdentKinds:
+    let ident = considerQuotedIdent(c, key)
+    var userPragma = strTableGet(c.userPragmas, ident)
+    if userPragma == nil:
+      let k = whichKeyword(ident)
+      # TODO: might as well make a list which is not accepted by `push`: emit, cast etc.
+      if k == wEmit:
+        localError(c.config, n.info, "an 'emit' pragma cannot be pushed")
+
 proc processPush(c: PContext, n: PNode, start: int) =
   if n[start-1].kind in nkPragmaCallKinds:
     localError(c.config, n.info, "'push' cannot have arguments")
@@ -478,6 +487,7 @@ proc processPush(c: PContext, n: PNode, start: int) =
   for i in start..<n.len:
     if not tryProcessOption(c, n[i], c.config.options):
       # simply store it somewhere:
+      checkPushedPragma(c, n[i])
       if x.otherPragmas.isNil:
         x.otherPragmas = newNodeI(nkPragma, n.info)
       x.otherPragmas.add n[i]
@@ -827,7 +837,6 @@ proc processEffectsOf(c: PContext, n: PNode; owner: PSym) =
 proc singlePragma(c: PContext, sym: PSym, n: PNode, i: var int,
                   validPragmas: TSpecialWords,
                   comesFromPush, isStatement: bool): bool =
-  result = false
   var it = n[i]
   let keyDeep = it.kind in nkPragmaCallKinds and it.len > 1
   var key = if keyDeep: it[0] else: it
@@ -1116,13 +1125,20 @@ proc singlePragma(c: PContext, sym: PSym, n: PNode, i: var int,
       of wFatal: fatal(c.config, it.info, expectStrLit(c, it))
       of wDefine: processDefine(c, it, sym)
       of wUndef: processUndef(c, it)
-      of wCompile: processCompile(c, it)
+      of wCompile:
+        let m = sym.getModule()
+        incl(m.flags, sfUsed)
+        processCompile(c, it)
       of wLink: processLink(c, it)
       of wPassl:
+        let m = sym.getModule()
+        incl(m.flags, sfUsed)
         let s = expectStrLit(c, it)
         extccomp.addLinkOption(c.config, s)
         recordPragma(c, it, "passl", s)
       of wPassc:
+        let m = sym.getModule()
+        incl(m.flags, sfUsed)
         let s = expectStrLit(c, it)
         extccomp.addCompileOption(c.config, s)
         recordPragma(c, it, "passc", s)
@@ -1284,9 +1300,7 @@ proc singlePragma(c: PContext, sym: PSym, n: PNode, i: var int,
       of wSystemRaisesDefect:
         sym.flags.incl sfSystemRaisesDefect
       of wVirtual:
-        processVirtual(c, it, sym, sfVirtual)
-      of wMember:
-        processVirtual(c, it, sym, sfMember)
+        processVirtual(c, it, sym)
 
       else: invalidPragma(c, it)
     elif comesFromPush and whichKeyword(ident) != wInvalid:

compiler/procfind.nim

@@ -34,7 +34,7 @@ proc searchForProcAux(c: PContext, scope: PScope, fn: PSym): PSym =
   var it: TIdentIter
   result = initIdentIter(it, scope.symbols, fn.name)
   while result != nil:
-    if result.kind == fn.kind and result.typ != nil: #and sameType(result.typ, fn.typ, flags):
+    if result.kind == fn.kind: #and sameType(result.typ, fn.typ, flags):
       case equalParams(result.typ.n, fn.typ.n)
       of paramsEqual:
         if (sfExported notin result.flags) and (sfExported in fn.flags):

compiler/renderer.nim

@@ -14,7 +14,7 @@
 {.used.}
 
 import
-  lexer, options, idents, strutils, ast, msgs, lineinfos
+  lexer, options, idents, strutils, ast, msgs, lineinfos, wordrecg
 
 when defined(nimPreviewSlimSystem):
   import std/[syncio, assertions, formatfloat]
@@ -76,8 +76,6 @@ proc isKeyword*(i: PIdent): bool =
   if (i.id >= ord(tokKeywordLow) - ord(tkSymbol)) and
       (i.id <= ord(tokKeywordHigh) - ord(tkSymbol)):
     result = true
-  else:
-    result = false
 
 proc isExported(n: PNode): bool =
   ## Checks if an ident is exported.
@@ -145,13 +143,19 @@ const
   MaxLineLen = 80
   LineCommentColumn = 30
 
-proc initSrcGen(renderFlags: TRenderFlags; config: ConfigRef): TSrcGen =
-  result = TSrcGen(comStack: @[], tokens: @[], indent: 0,
-                   lineLen: 0, pos: 0, idx: 0, buf: "",
-                   flags: renderFlags, pendingNL: -1,
-                   pendingWhitespace: -1, inside: {},
-                   config: config
-                   )
+proc initSrcGen(g: var TSrcGen, renderFlags: TRenderFlags; config: ConfigRef) =
+  g.comStack = @[]
+  g.tokens = @[]
+  g.indent = 0
+  g.lineLen = 0
+  g.pos = 0
+  g.idx = 0
+  g.buf = ""
+  g.flags = renderFlags
+  g.pendingNL = -1
+  g.pendingWhitespace = -1
+  g.inside = {}
+  g.config = config
 
 proc addTok(g: var TSrcGen, kind: TokType, s: string; sym: PSym = nil) =
   g.tokens.add TRenderTok(kind: kind, length: int16(s.len), sym: sym)
@@ -270,7 +274,6 @@ proc putComment(g: var TSrcGen, s: string) =
   optNL(g)
 
 proc maxLineLength(s: string): int =
-  result = 0
   if s.len == 0: return 0
   var i = 0
   let hi = s.len - 1
@@ -368,7 +371,6 @@ proc litAux(g: TSrcGen; n: PNode, x: BiggestInt, size: int): string =
                           tyLent, tyDistinct, tyOrdinal, tyAlias, tySink}:
       result = lastSon(result)
 
-  result = ""
   let typ = n.typ.skip
   if typ != nil and typ.kind in {tyBool, tyEnum}:
     if sfPure in typ.sym.flags:
@@ -486,7 +488,6 @@ proc referencesUsing(n: PNode): bool =
 
 proc lsub(g: TSrcGen; n: PNode): int =
   # computes the length of a tree
-  result = 0
   if isNil(n): return 0
   if shouldRenderComment(g, n): return MaxLineLen + 1
   case n.kind
@@ -624,12 +625,14 @@ type
 const
   emptyContext: TContext = (spacing: 0, flags: {})
 
-proc initContext(): TContext =
-  result = (spacing: 0, flags: {})
+proc initContext(c: var TContext) =
+  c.spacing = 0
+  c.flags = {}
 
 proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false)
 proc gsub(g: var TSrcGen, n: PNode, fromStmtList = false) =
-  var c: TContext = initContext()
+  var c: TContext
+  initContext(c)
   gsub(g, n, c, fromStmtList = fromStmtList)
 
 proc hasCom(n: PNode): bool =
@@ -759,8 +762,9 @@ proc gcond(g: var TSrcGen, n: PNode) =
     put(g, tkParRi, ")")
 
 proc gif(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
   gcond(g, n[0][0])
+  initContext(c)
   putWithSpace(g, tkColon, ":")
   if longMode(g, n) or (lsub(g, n[0][1]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
@@ -771,18 +775,20 @@ proc gif(g: var TSrcGen, n: PNode) =
     gsub(g, n[i], c)
 
 proc gwhile(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
   putWithSpace(g, tkWhile, "while")
   gcond(g, n[0])
   putWithSpace(g, tkColon, ":")
+  initContext(c)
   if longMode(g, n) or (lsub(g, n[1]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
   gstmts(g, n[1], c)
 
 proc gpattern(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
   put(g, tkCurlyLe, "{")
+  initContext(c)
   if longMode(g, n) or (lsub(g, n[0]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
@@ -790,18 +796,20 @@ proc gpattern(g: var TSrcGen, n: PNode) =
   put(g, tkCurlyRi, "}")
 
 proc gpragmaBlock(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
   gsub(g, n[0])
   putWithSpace(g, tkColon, ":")
+  initContext(c)
   if longMode(g, n) or (lsub(g, n[1]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
   gstmts(g, n[1], c)
 
 proc gtry(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
   put(g, tkTry, "try")
   putWithSpace(g, tkColon, ":")
+  initContext(c)
   if longMode(g, n) or (lsub(g, n[0]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
@@ -809,8 +817,9 @@ proc gtry(g: var TSrcGen, n: PNode) =
   gsons(g, n, c, 1)
 
 proc gfor(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
   putWithSpace(g, tkFor, "for")
+  initContext(c)
   if longMode(g, n) or
       (lsub(g, n[^1]) + lsub(g, n[^2]) + 6 + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
@@ -823,7 +832,8 @@ proc gfor(g: var TSrcGen, n: PNode) =
   gstmts(g, n[^1], c)
 
 proc gcase(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
+  initContext(c)
   if n.len == 0: return
   var last = if n[^1].kind == nkElse: -2 else: -1
   if longMode(g, n, 0, last): incl(c.flags, rfLongMode)
@@ -833,17 +843,17 @@ proc gcase(g: var TSrcGen, n: PNode) =
   optNL(g)
   gsons(g, n, c, 1, last)
   if last == - 2:
-    c = initContext()
+    initContext(c)
     if longMode(g, n[^1]): incl(c.flags, rfLongMode)
     gsub(g, n[^1], c)
 
 proc genSymSuffix(result: var string, s: PSym) {.inline.} =
-  if sfGenSym in s.flags:
+  if sfGenSym in s.flags and s.name.id != ord(wUnderscore):
     result.add '_'
     result.addInt s.id
 
 proc gproc(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
   if n[namePos].kind == nkSym:
     let s = n[namePos].sym
     var ret = renderDefinitionName(s)
@@ -864,13 +874,13 @@ proc gproc(g: var TSrcGen, n: PNode) =
   if renderNoPragmas notin g.flags:
     gsub(g, n[pragmasPos])
   if renderNoBody notin g.flags:
-    if n[bodyPos].kind != nkEmpty:
+    if n.len > bodyPos and n[bodyPos].kind != nkEmpty:
       put(g, tkSpaces, Space)
       putWithSpace(g, tkEquals, "=")
       indentNL(g)
       gcoms(g)
       dedent(g)
-      c = initContext()
+      initContext(c)
       gstmts(g, n[bodyPos], c)
       putNL(g)
     else:
@@ -879,7 +889,8 @@ proc gproc(g: var TSrcGen, n: PNode) =
       dedent(g)
 
 proc gTypeClassTy(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
+  initContext(c)
   putWithSpace(g, tkConcept, "concept")
   gsons(g, n[0], c) # arglist
   gsub(g, n[1]) # pragmas
@@ -898,7 +909,8 @@ proc gblock(g: var TSrcGen, n: PNode) =
   if n.len == 0:
     return
 
-  var c: TContext = initContext()
+  var c: TContext
+  initContext(c)
 
   if n[0].kind != nkEmpty:
     putWithSpace(g, tkBlock, "block")
@@ -918,9 +930,10 @@ proc gblock(g: var TSrcGen, n: PNode) =
   gstmts(g, n[1], c)
 
 proc gstaticStmt(g: var TSrcGen, n: PNode) =
-  var c: TContext = initContext()
+  var c: TContext
   putWithSpace(g, tkStatic, "static")
   putWithSpace(g, tkColon, ":")
+  initContext(c)
   if longMode(g, n) or (lsub(g, n[0]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
@@ -958,7 +971,9 @@ proc gident(g: var TSrcGen, n: PNode) =
       s.addInt localId
     if sfCursor in n.sym.flags:
       s.add "_cursor"
-  elif n.kind == nkSym and (renderIds in g.flags or sfGenSym in n.sym.flags or n.sym.kind == skTemp):
+  elif n.kind == nkSym and (renderIds in g.flags or
+      (sfGenSym in n.sym.flags and n.sym.name.id != ord(wUnderscore)) or
+      n.sym.kind == skTemp):
     s.add '_'
     s.addInt n.sym.id
     when defined(debugMagics):
@@ -992,7 +1007,6 @@ proc bracketKind*(g: TSrcGen, n: PNode): BracketKind =
     case n.kind
     of nkClosedSymChoice, nkOpenSymChoice:
       if n.len > 0: result = bracketKind(g, n[0])
-      else: result = bkNone
     of nkSym:
       result = case n.sym.name.s
         of "[]": bkBracket
@@ -1001,8 +1015,6 @@ proc bracketKind*(g: TSrcGen, n: PNode): BracketKind =
         of "{}=": bkCurlyAsgn
         else: bkNone
     else: result = bkNone
-  else:
-    result = bkNone
 
 proc skipHiddenNodes(n: PNode): PNode =
   result = n
@@ -1075,13 +1087,11 @@ proc isCustomLit(n: PNode): bool =
   if n.len == 2 and n[0].kind == nkRStrLit:
     let ident = n[1].getPIdent
     result = ident != nil and ident.s.startsWith('\'')
-  else:
-    result = false
 
 proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
   if isNil(n): return
   var
-    a: TContext = default(TContext)
+    a: TContext
   if shouldRenderComment(g, n): pushCom(g, n)
   case n.kind                 # atoms:
   of nkTripleStrLit: put(g, tkTripleStrLit, atom(g, n))
@@ -1429,8 +1439,6 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
         if n.kind in {nkIdent, nkSym}:
           let tmp = n.getPIdent.s
           result = tmp.len > 0 and tmp[0] in {'a'..'z', 'A'..'Z'}
-        else:
-          result = false
       var useSpace = false
       if i == 1 and n[0].kind == nkIdent and n[0].ident.s in ["=", "'"]:
         if not n[1].isAlpha: # handle `=destroy`, `'big'
@@ -1518,17 +1526,16 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
         gsub(g, n[0])
         gsub(g, n[1])
         gcoms(g)
+        indentNL(g)
         gsub(g, n[2])
+        dedent(g)
     else:
       put(g, tkObject, "object")
   of nkRecList:
-    indentNL(g)
     for i in 0..<n.len:
       optNL(g)
       gsub(g, n[i], c)
       gcoms(g)
-    dedent(g)
-    putNL(g)
   of nkOfInherit:
     putWithSpace(g, tkOf, "of")
     gsub(g, n, 0)
@@ -1613,7 +1620,7 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
   of nkTypeSection:
     gsection(g, n, emptyContext, tkType, "type")
   of nkConstSection:
-    a = initContext()
+    initContext(a)
     incl(a.flags, rfInConstExpr)
     gsection(g, n, a, tkConst, "const")
   of nkVarSection, nkLetSection, nkUsingStmt:
@@ -1781,11 +1788,13 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
     gsub(g, n, 0)
     put(g, tkParRi, ")")
   of nkGotoState:
-    var c: TContext = initContext()
+    var c: TContext
+    initContext c
     putWithSpace g, tkSymbol, "goto"
     gsons(g, n, c)
   of nkState:
-    var c: TContext = initContext()
+    var c: TContext
+    initContext c
     putWithSpace g, tkSymbol, "state"
     gsub(g, n[0], c)
     putWithSpace(g, tkColon, ":")
@@ -1809,7 +1818,8 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
 
 proc renderTree*(n: PNode, renderFlags: TRenderFlags = {}): string =
   if n == nil: return "<nil tree>"
-  var g: TSrcGen = initSrcGen(renderFlags, newPartialConfigRef())
+  var g: TSrcGen
+  initSrcGen(g, renderFlags, newPartialConfigRef())
   # do not indent the initial statement list so that
   # writeFile("file.nim", repr n)
   # produces working Nim code:
@@ -1826,8 +1836,9 @@ proc renderModule*(n: PNode, outfile: string,
                    fid = FileIndex(-1);
                    conf: ConfigRef = nil) =
   var
-    f: File = default(File)
-    g: TSrcGen = initSrcGen(renderFlags, conf)
+    f: File
+    g: TSrcGen
+  initSrcGen(g, renderFlags, conf)
   g.fid = fid
   for i in 0..<n.len:
     gsub(g, n[i])
@@ -1843,9 +1854,9 @@ proc renderModule*(n: PNode, outfile: string,
   else:
     rawMessage(g.config, errGenerated, "cannot open file: " & outfile)
 
-proc initTokRender*(n: PNode, renderFlags: TRenderFlags = {}): TSrcGen =
-  result = initSrcGen(renderFlags, newPartialConfigRef())
-  gsub(result, n)
+proc initTokRender*(r: var TSrcGen, n: PNode, renderFlags: TRenderFlags = {}) =
+  initSrcGen(r, renderFlags, newPartialConfigRef())
+  gsub(r, n)
 
 proc getNextTok*(r: var TSrcGen, kind: var TokType, literal: var string) =
   if r.idx < r.tokens.len:

compiler/renderverbatim.nim

@@ -40,7 +40,6 @@ type LineData = object
 
 proc tripleStrLitStartsAtNextLine(conf: ConfigRef, n: PNode): bool =
   # enabling TLineInfo.offsetA,offsetB would probably make this easier
-  result = false
   const tripleQuote = "\"\"\""
   let src = sourceLine(conf, n.info)
   let col = n.info.col

compiler/reorder.nim

@@ -25,11 +25,17 @@ when defined(nimDebugReorder):
   var idNames = newTable[int, string]()
 
 proc newDepN(id: int, pnode: PNode): DepN =
-  result = DepN(id: id, pnode: pnode, idx: -1,
-                lowLink: -1, onStack: false,
-                kids: @[], hAQ: -1, hIS: -1,
-                hB: -1, hCmd: -1
-  )
+  new(result)
+  result.id = id
+  result.pnode = pnode
+  result.idx = -1
+  result.lowLink = -1
+  result.onStack = false
+  result.kids = @[]
+  result.hAQ = -1
+  result.hIS = -1
+  result.hB = -1
+  result.hCmd = -1
   when defined(nimDebugReorder):
     result.expls = @[]
 
@@ -108,8 +114,7 @@ proc computeDeps(cache: IdentCache; n: PNode, declares, uses: var IntSet; topLev
     # XXX: for callables, this technically adds the return type dep before args
     for i in 0..<n.safeLen: deps(n[i])
 
-proc hasIncludes(n: PNode): bool =
-  result = false
+proc hasIncludes(n:PNode): bool =
   for a in n:
     if a.kind == nkIncludeStmt:
       return true
@@ -229,9 +234,8 @@ proc hasImportStmt(n: PNode): bool =
   # i it contains one
   case n.kind
   of nkImportStmt, nkFromStmt, nkImportExceptStmt:
-    result = true
+    return true
   of nkStmtList, nkStmtListExpr, nkWhenStmt, nkElifBranch, nkElse, nkStaticStmt:
-    result = false
     for a in n:
       if a.hasImportStmt:
         return true
@@ -264,7 +268,6 @@ proc hasCommand(n: DepN): bool =
   result = bool(n.hCmd)
 
 proc hasAccQuoted(n: PNode): bool =
-  result = false
   if n.kind == nkAccQuoted:
     return true
   for a in n:
@@ -280,7 +283,6 @@ proc hasAccQuotedDef(n: PNode): bool =
   of extendedProcDefs:
     result = n[0].hasAccQuoted
   of nkStmtList, nkStmtListExpr, nkWhenStmt, nkElifBranch, nkElse, nkStaticStmt:
-    result = false
     for a in n:
       if hasAccQuotedDef(a):
         return true
@@ -301,7 +303,6 @@ proc hasBody(n: PNode): bool =
   of extendedProcDefs:
     result = n[^1].kind == nkStmtList
   of nkStmtList, nkStmtListExpr, nkWhenStmt, nkElifBranch, nkElse, nkStaticStmt:
-    result = false
     for a in n:
       if a.hasBody:
         return true
@@ -314,7 +315,6 @@ proc hasBody(n: DepN): bool =
   result = bool(n.hB)
 
 proc intersects(s1, s2: IntSet): bool =
-  result = false
   for a in s1:
     if s2.contains(a):
       return true
@@ -393,7 +393,6 @@ proc strongConnect(v: var DepN, idx: var int, s: var seq[DepN],
 proc getStrongComponents(g: var DepG): seq[seq[DepN]] =
   ## Tarjan's algorithm. Performs a topological sort
   ## and detects strongly connected components.
-  result = @[]
   var s: seq[DepN]
   var idx = 0
   for v in g.mitems:
@@ -403,7 +402,6 @@ proc getStrongComponents(g: var DepG): seq[seq[DepN]] =
 proc hasForbiddenPragma(n: PNode): bool =
   # Checks if the tree node has some pragmas that do not
   # play well with reordering, like the push/pop pragma
-  result = false
   for a in n:
     if a.kind == nkPragma and a[0].kind == nkIdent and
         a[0].ident.s == "push":

compiler/rodutils.nim

@@ -61,7 +61,6 @@ proc toStrMaxPrecision*(f: BiggestFloat | float32): string =
   of fcNegInf:
     result = "-INF"
   else:
-    result = ""
     result.addFloatRoundtrip(f)
     result.add literalPostfix
 

compiler/ropes.nim

@@ -43,7 +43,7 @@ proc writeRope*(f: File, r: Rope) =
   write(f, r)
 
 proc writeRope*(head: Rope, filename: AbsoluteFile): bool =
-  var f: File = default(File)
+  var f: File
   if open(f, filename.string, fmWrite):
     writeRope(f, head)
     close(f)
@@ -76,7 +76,7 @@ proc runtimeFormat*(frmt: FormatStr, args: openArray[Rope]): Rope =
           if i >= frmt.len or frmt[i] notin {'0'..'9'}: break
         num = j
         if j > high(args) + 1:
-          raiseAssert "invalid format string: " & frmt
+          doAssert false, "invalid format string: " & frmt
         else:
           result.add(args[j-1])
       of '{':
@@ -88,10 +88,10 @@ proc runtimeFormat*(frmt: FormatStr, args: openArray[Rope]): Rope =
         num = j
         if frmt[i] == '}': inc(i)
         else:
-          raiseAssert "invalid format string: " & frmt
+          doAssert false, "invalid format string: " & frmt
 
         if j > high(args) + 1:
-          raiseAssert "invalid format string: " & frmt
+          doAssert false, "invalid format string: " & frmt
         else:
           result.add(args[j-1])
       of 'n':
@@ -101,7 +101,7 @@ proc runtimeFormat*(frmt: FormatStr, args: openArray[Rope]): Rope =
         result.add("\n")
         inc(i)
       else:
-        raiseAssert "invalid format string: " & frmt
+        doAssert false, "invalid format string: " & frmt
     else:
       result.add(frmt[i])
       inc(i)
@@ -119,7 +119,7 @@ const
 proc equalsFile*(s: Rope, f: File): bool =
   ## returns true if the contents of the file `f` equal `r`.
   var
-    buf: array[bufSize, char] = default(array[bufSize, char])
+    buf: array[bufSize, char]
     bpos = buf.len
     blen = buf.len
     btotal = 0
@@ -151,7 +151,7 @@ proc equalsFile*(s: Rope, f: File): bool =
 proc equalsFile*(r: Rope, filename: AbsoluteFile): bool =
   ## returns true if the contents of the file `f` equal `r`. If `f` does not
   ## exist, false is returned.
-  var f: File = default(File)
+  var f: File
   result = open(f, filename.string)
   if result:
     result = equalsFile(r, f)

compiler/scriptconfig.nim

@@ -240,7 +240,7 @@ proc runNimScript*(cache: IdentCache; scriptName: AbsoluteFile;
     of gcAtomicArc:
       defineSymbol(conf.symbols, "gcatomicarc")
     else:
-      raiseAssert "unreachable"
+      doAssert false, "unreachable"
 
   # ensure we load 'system.nim' again for the real non-config stuff!
   resetSystemArtifacts(graph)

compiler/sem.nim

@@ -26,7 +26,10 @@ when not defined(leanCompiler):
   import spawn
 
 when defined(nimPreviewSlimSystem):
-  import std/formatfloat
+  import std/[
+    formatfloat,
+    assertions,
+  ]
 
 # implementation
 
@@ -96,7 +99,6 @@ proc fitNode(c: PContext, formal: PType, arg: PNode; info: TLineInfo): PNode =
     result.typ = formal
   elif arg.kind in nkSymChoices and formal.skipTypes(abstractInst).kind == tyEnum:
     # Pick the right 'sym' from the sym choice by looking at 'formal' type:
-    result = nil
     for ch in arg:
       if sameType(ch.typ, formal):
         return getConstExpr(c.module, ch, c.idgen, c.graph)
@@ -150,7 +152,7 @@ proc commonType*(c: PContext; x, y: PType): PType =
     let idx = ord(b.kind == tyArray)
     if a[idx].kind == tyEmpty: return y
   elif a.kind == tyTuple and b.kind == tyTuple and a.len == b.len:
-    var nt: PType = nil
+    var nt: PType
     for i in 0..<a.len:
       let aEmpty = isEmptyContainer(a[i])
       let bEmpty = isEmptyContainer(b[i])
@@ -206,13 +208,78 @@ proc commonType*(c: PContext; x, y: PType): PType =
         result = newType(k, nextTypeId(c.idgen), r.owner)
         result.addSonSkipIntLit(r, c.idgen)
 
+const shouldChckCovered = {tyInt..tyInt64, tyChar, tyEnum, tyUInt..tyUInt64, tyBool}
+proc shouldCheckCaseCovered(caseTyp: PType): bool =
+  result = false
+  case caseTyp.kind
+  of shouldChckCovered:
+    result = true
+  of tyRange:
+    if skipTypes(caseTyp[0], abstractInst).kind in shouldChckCovered:
+      result = true
+  else:
+    discard
+
 proc endsInNoReturn(n: PNode): bool =
-  # check if expr ends in raise exception or call of noreturn proc
+  ## check if expr ends the block like raising or call of noreturn procs do
+  result = false # assume it does return
+
+  template checkBranch(branch) =
+    if not endsInNoReturn(branch):
+      # proved a branch returns
+      return false
+
   var it = n
+  # skip these beforehand, no special handling needed
   while it.kind in {nkStmtList, nkStmtListExpr} and it.len > 0:
     it = it.lastSon
-  result = it.kind in nkLastBlockStmts or
-    it.kind in nkCallKinds and it[0].kind == nkSym and sfNoReturn in it[0].sym.flags
+
+  case it.kind
+  of nkIfStmt:
+    var hasElse = false
+    for branch in it:
+      checkBranch:
+        if branch.len == 2:
+          branch[1]
+        elif branch.len == 1:
+          hasElse = true
+          branch[0]
+        else:
+          raiseAssert "Malformed `if` statement during endsInNoReturn"
+    # none of the branches returned
+    result = hasElse # Only truly a no-return when it's exhaustive
+  of nkCaseStmt:
+    let caseTyp = skipTypes(it[0].typ, abstractVar-{tyTypeDesc})
+    # semCase should already have checked for exhaustiveness in this case
+    # effectively the same as having an else
+    var hasElse = caseTyp.shouldCheckCaseCovered()
+
+    # actual noreturn checks
+    for i in 1 ..< it.len:
+      let branch = it[i]
+      checkBranch:
+        case branch.kind
+        of nkOfBranch:
+          branch[^1]
+        of nkElifBranch:
+          branch[1]
+        of nkElse:
+          hasElse = true
+          branch[0]
+        else:
+          raiseAssert "Malformed `case` statement in endsInNoReturn"
+    # Can only guarantee a noreturn if there is an else or it's exhaustive
+    result = hasElse
+  of nkTryStmt:
+    checkBranch(it[0])
+    for i in 1 ..< it.len:
+      let branch = it[i]
+      checkBranch(branch[^1])
+    # none of the branches returned
+    result = true
+  else:
+    result = it.kind in nkLastBlockStmts or
+      it.kind in nkCallKinds and it[0].kind == nkSym and sfNoReturn in it[0].sym.flags
 
 proc commonType*(c: PContext; x: PType, y: PNode): PType =
   # ignore exception raising branches in case/if expressions
@@ -244,6 +311,8 @@ proc newSymG*(kind: TSymKind, n: PNode, c: PContext): PSym =
     result.owner = getCurrOwner(c)
   else:
     result = newSym(kind, considerQuotedIdent(c, n), c.idgen, getCurrOwner(c), n.info)
+    if find(result.name.s, '`') >= 0:
+      result.flags.incl sfWasGenSym
   #if kind in {skForVar, skLet, skVar} and result.owner.kind == skModule:
   #  incl(result.flags, sfGlobal)
   when defined(nimsuggest):
@@ -253,7 +322,7 @@ proc semIdentVis(c: PContext, kind: TSymKind, n: PNode,
                  allowed: TSymFlags): PSym
   # identifier with visibility
 proc semIdentWithPragma(c: PContext, kind: TSymKind, n: PNode,
-                        allowed: TSymFlags): PSym
+                        allowed: TSymFlags, fromTopLevel = false): PSym
 
 proc typeAllowedCheck(c: PContext; info: TLineInfo; typ: PType; kind: TSymKind;
                       flags: TTypeAllowedFlags = {}) =
@@ -306,7 +375,6 @@ when false:
       result = isOpImpl(c, n)
 
 proc hasCycle(n: PNode): bool =
-  result = false
   incl n.flags, nfNone
   for i in 0..<n.safeLen:
     if nfNone in n[i].flags or hasCycle(n[i]):
@@ -471,9 +539,15 @@ proc semAfterMacroCall(c: PContext, call, macroResult: PNode,
         # e.g. template foo(T: typedesc): seq[T]
         # We will instantiate the return type here, because
         # we now know the supplied arguments
-        var paramTypes = initIdTable()
+        var paramTypes = newIdTable()
         for param, value in genericParamsInMacroCall(s, call):
-          idTablePut(paramTypes, param.typ, value.typ)
+          var givenType = value.typ
+          # the sym nodes used for the supplied generic arguments for
+          # templates and macros leave type nil so regular sem can handle it
+          # in this case, get the type directly from the sym
+          if givenType == nil and value.kind == nkSym and value.sym.typ != nil:
+            givenType = value.sym.typ
+          idTablePut(paramTypes, param.typ, givenType)
 
         retType = generateTypeInstance(c, paramTypes,
                                        macroResult.info, retType)
@@ -550,7 +624,6 @@ proc setGenericParamsMisc(c: PContext; n: PNode) =
     n[miscPos][1] = orig
 
 proc caseBranchMatchesExpr(branch, matched: PNode): bool =
-  result = false
   for i in 0 ..< branch.len-1:
     if branch[i].kind == nkRange:
       if overlap(branch[i], matched): return true
@@ -558,7 +631,6 @@ proc caseBranchMatchesExpr(branch, matched: PNode): bool =
       return true
 
 proc pickCaseBranchIndex(caseExpr, matched: PNode): int =
-  result = 0
   let endsWithElse = caseExpr[^1].kind == nkElse
   for i in 1..<caseExpr.len - endsWithElse.int:
     if caseExpr[i].caseBranchMatchesExpr(matched):
@@ -573,7 +645,6 @@ proc defaultNodeField(c: PContext, a: PNode, checkDefault: bool): PNode
 const defaultFieldsSkipTypes = {tyGenericInst, tyAlias, tySink}
 
 proc defaultFieldsForTuple(c: PContext, recNode: PNode, hasDefault: var bool, checkDefault: bool): seq[PNode] =
-  result = @[]
   case recNode.kind
   of nkRecList:
     for field in recNode:
@@ -603,10 +674,9 @@ proc defaultFieldsForTuple(c: PContext, recNode: PNode, hasDefault: var bool, ch
       asgnExpr.typ = recNode.typ
       result.add newTree(nkExprColonExpr, recNode, asgnExpr)
   else:
-    raiseAssert "unreachable"
+    doAssert false
 
 proc defaultFieldsForTheUninitialized(c: PContext, recNode: PNode, checkDefault: bool): seq[PNode] =
-  result = @[]
   case recNode.kind
   of nkRecList:
     for field in recNode:
@@ -639,7 +709,7 @@ proc defaultFieldsForTheUninitialized(c: PContext, recNode: PNode, checkDefault:
         asgnExpr.flags.incl nfSkipFieldChecking
         result.add newTree(nkExprColonExpr, recNode, asgnExpr)
   else:
-    raiseAssert "unreachable"
+    doAssert false
 
 proc defaultNodeField(c: PContext, a: PNode, aTyp: PType, checkDefault: bool): PNode =
   let aTypSkip = aTyp.skipTypes(defaultFieldsSkipTypes)
@@ -650,8 +720,6 @@ proc defaultNodeField(c: PContext, a: PNode, aTyp: PType, checkDefault: bool): P
       asgnExpr.typ = aTyp
       asgnExpr.sons.add child
       result = semExpr(c, asgnExpr)
-    else:
-      result = nil
   elif aTypSkip.kind == tyArray:
     let child = defaultNodeField(c, a, aTypSkip[1], checkDefault)
 
@@ -663,8 +731,6 @@ proc defaultNodeField(c: PContext, a: PNode, aTyp: PType, checkDefault: bool): P
               node
                 ))
       result.typ = aTyp
-    else:
-      result = nil
   elif aTypSkip.kind == tyTuple:
     var hasDefault = false
     if aTypSkip.n != nil:
@@ -674,12 +740,6 @@ proc defaultNodeField(c: PContext, a: PNode, aTyp: PType, checkDefault: bool): P
         result.typ = aTyp
         result.sons.add children
         result = semExpr(c, result)
-      else:
-        result = nil
-    else:
-      result = nil
-  else:
-    result = nil
 
 proc defaultNodeField(c: PContext, a: PNode, checkDefault: bool): PNode =
   result = defaultNodeField(c, a, a.typ, checkDefault)
@@ -739,19 +799,17 @@ proc isImportSystemStmt(g: ModuleGraph; n: PNode): bool =
         break
   case n.kind
   of nkImportStmt:
-    result = false
     for x in n:
       if x.kind == nkIdent:
         let f = checkModuleName(g.config, x, false)
         if f == g.systemModule.info.fileIndex:
           return true
   of nkImportExceptStmt, nkFromStmt:
-    result = false
     if n[0].kind == nkIdent:
       let f = checkModuleName(g.config, n[0], false)
       if f == g.systemModule.info.fileIndex:
         return true
-  else: result = false
+  else: discard
 
 proc isEmptyTree(n: PNode): bool =
   case n.kind
@@ -762,58 +820,6 @@ proc isEmptyTree(n: PNode): bool =
   of nkEmpty, nkCommentStmt: result = true
   else: result = false
 
-proc decl(c: PContext, n: PNode, kind: TSymKind): PNode =
-  if n[0].kind == nkIdent:
-    var s = newSym(kind, n[0].ident, c.idgen, getCurrOwner(c), n.info)
-    s.flags.incl sfToplevelDecl
-    # pragmaCallable(c, s, n, allRoutinePragmas)
-
-    result = n
-    if n[^1].kind != nkEmpty:
-      if s.kind in OverloadableSyms:
-        addInterfaceOverloadableSymAt(c, c.currentScope, s)
-      else:
-        addInterfaceDeclAt(c, c.currentScope, s)
-
-    result[0] = newSymNode(s)
-  else:
-    result = n
-
-import reorder
-
-proc semSignature(c: PContext, n: PNode): PNode =
-  case n.kind
-  of nkProcDef:
-    result = decl(c, n, skProc)
-  of nkMethodDef:
-    result = decl(c, n, skMethod)
-  of nkConverterDef:
-    result = decl(c, n, skConverter)
-  of nkMacroDef:
-    result = decl(c, n, skMacro)
-  of nkTemplateDef:
-    result = decl(c, n, skTemplate)
-  of nkIteratorDef:
-    result = decl(c, n, skIterator)
-  of nkIncludeStmt:
-    result = n
-    for i in 0..<n.len:
-      var f = checkModuleName(c.config, n[i])
-      if f != InvalidFileIdx:
-        if containsOrIncl(c.includedFiles, f.int):
-          localError(c.config, n[i].info, "recursive dependency: '$1'" %
-            toMsgFilename(c.config, f))
-        else:
-          let nn = includeModule(c.graph, c.module, f)
-          result = semSignature(c, nn)
-          excl(c.includedFiles, f.int)
-  of nkStmtList:
-    result = copyNode(n)
-    for i in 0..<n.len:
-      result.add semSignature(c, n[i])
-  else:
-    result = n
-
 proc semStmtAndGenerateGenerics(c: PContext, n: PNode): PNode =
   if c.topStmts == 0 and not isImportSystemStmt(c.graph, n):
     if sfSystemModule notin c.module.flags and not isEmptyTree(n):
@@ -827,9 +833,6 @@ proc semStmtAndGenerateGenerics(c: PContext, n: PNode): PNode =
     result = semAllTypeSections(c, n)
   else:
     result = n
-  # if noforwardDecl in c.features:
-  #   debug result
-  result = semSignature(c, result)
   result = semStmt(c, result, {})
   when false:
     # Code generators are lazy now and can deal with undeclared procs, so these

compiler/semcall.nim

@@ -82,7 +82,7 @@ proc pickBestCandidate(c: PContext, headSymbol: PNode,
 
   # starts at 1 because 0 is already done with setup, only needs checking
   var nextSymIndex = 1
-  var z: TCandidate = default(TCandidate) # current candidate
+  var z: TCandidate # current candidate
   while true:
     determineType(c, sym)
     initCandidate(c, z, sym, initialBinding, scope, diagnosticsFlag)
@@ -215,7 +215,7 @@ proc presentFailedCandidates(c: PContext, n: PNode, errors: CandidateErrors):
 
   var maybeWrongSpace = false
 
-  var candidatesAll: seq[string] = @[]
+  var candidatesAll: seq[string]
   var candidates = ""
   var skipped = 0
   for err in errors:
@@ -236,44 +236,89 @@ proc presentFailedCandidates(c: PContext, n: PNode, errors: CandidateErrors):
     candidates.add("\n")
     let nArg = if err.firstMismatch.arg < n.len: n[err.firstMismatch.arg] else: nil
     let nameParam = if err.firstMismatch.formal != nil: err.firstMismatch.formal.name.s else: ""
-    if n.len > 1 and verboseTypeMismatch in c.config.legacyFeatures:
-      candidates.add("  first type mismatch at position: " & $err.firstMismatch.arg)
-      # candidates.add "\n  reason: " & $err.firstMismatch.kind # for debugging
-      case err.firstMismatch.kind
-      of kUnknownNamedParam:
-        if nArg == nil:
-          candidates.add("\n  unknown named parameter")
-        else:
-          candidates.add("\n  unknown named parameter: " & $nArg[0])
-      of kAlreadyGiven: candidates.add("\n  named param already provided: " & $nArg[0])
-      of kPositionalAlreadyGiven: candidates.add("\n  positional param was already given as named param")
-      of kExtraArg: candidates.add("\n  extra argument given")
-      of kMissingParam: candidates.add("\n  missing parameter: " & nameParam)
-      of kTypeMismatch, kVarNeeded:
-        doAssert nArg != nil
-        let wanted = err.firstMismatch.formal.typ
-        doAssert err.firstMismatch.formal != nil
-        candidates.add("\n  required type for " & nameParam &  ": ")
-        candidates.addTypeDeclVerboseMaybe(c.config, wanted)
-        candidates.add "\n  but expression '"
-        if err.firstMismatch.kind == kVarNeeded:
+    if n.len > 1:
+      if verboseTypeMismatch notin c.config.legacyFeatures:
+        case err.firstMismatch.kind
+        of kUnknownNamedParam:
+          if nArg == nil:
+            candidates.add("  unknown named parameter")
+          else:
+            candidates.add("  unknown named parameter: " & $nArg[0])
+          candidates.add "\n"
+        of kAlreadyGiven:
+          candidates.add("  named param already provided: " & $nArg[0])
+          candidates.add "\n"
+        of kPositionalAlreadyGiven:
+          candidates.add("  positional param was already given as named param")
+          candidates.add "\n"
+        of kExtraArg:
+          candidates.add("  extra argument given")
+          candidates.add "\n"
+        of kMissingParam:
+          candidates.add("  missing parameter: " & nameParam)
+          candidates.add "\n"
+        of kVarNeeded:
+          doAssert nArg != nil
+          doAssert err.firstMismatch.formal != nil
+          candidates.add "  expression '"
           candidates.add renderNotLValue(nArg)
           candidates.add "' is immutable, not 'var'"
-        else:
-          candidates.add renderTree(nArg)
-          candidates.add "' is of type: "
-          let got = nArg.typ
-          candidates.addTypeDeclVerboseMaybe(c.config, got)
+          candidates.add "\n"
+        of kTypeMismatch:
+          doAssert nArg != nil
+          let wanted = err.firstMismatch.formal.typ
+          doAssert err.firstMismatch.formal != nil
           doAssert wanted != nil
-          if got != nil:
-            if got.kind == tyProc and wanted.kind == tyProc:
-              # These are proc mismatches so,
-              # add the extra explict detail of the mismatch
-              candidates.addPragmaAndCallConvMismatch(wanted, got, c.config)
+          let got = nArg.typ
+          if got != nil and got.kind == tyProc and wanted.kind == tyProc:
+            # These are proc mismatches so,
+            # add the extra explict detail of the mismatch
+            candidates.add "  expression '"
+            candidates.add renderTree(nArg)
+            candidates.add "' is of type: "
+            candidates.addTypeDeclVerboseMaybe(c.config, got)
+            candidates.addPragmaAndCallConvMismatch(wanted, got, c.config)
             effectProblem(wanted, got, candidates, c)
+            candidates.add "\n"
+        of kUnknown: discard "do not break 'nim check'"
+      else:
+        candidates.add("  first type mismatch at position: " & $err.firstMismatch.arg)
+        # candidates.add "\n  reason: " & $err.firstMismatch.kind # for debugging
+        case err.firstMismatch.kind
+        of kUnknownNamedParam:
+          if nArg == nil:
+            candidates.add("\n  unknown named parameter")
+          else:
+            candidates.add("\n  unknown named parameter: " & $nArg[0])
+        of kAlreadyGiven: candidates.add("\n  named param already provided: " & $nArg[0])
+        of kPositionalAlreadyGiven: candidates.add("\n  positional param was already given as named param")
+        of kExtraArg: candidates.add("\n  extra argument given")
+        of kMissingParam: candidates.add("\n  missing parameter: " & nameParam)
+        of kTypeMismatch, kVarNeeded:
+          doAssert nArg != nil
+          let wanted = err.firstMismatch.formal.typ
+          doAssert err.firstMismatch.formal != nil
+          candidates.add("\n  required type for " & nameParam &  ": ")
+          candidates.addTypeDeclVerboseMaybe(c.config, wanted)
+          candidates.add "\n  but expression '"
+          if err.firstMismatch.kind == kVarNeeded:
+            candidates.add renderNotLValue(nArg)
+            candidates.add "' is immutable, not 'var'"
+          else:
+            candidates.add renderTree(nArg)
+            candidates.add "' is of type: "
+            let got = nArg.typ
+            candidates.addTypeDeclVerboseMaybe(c.config, got)
+            doAssert wanted != nil
+            if got != nil:
+              if got.kind == tyProc and wanted.kind == tyProc:
+                # These are proc mismatches so,
+                # add the extra explict detail of the mismatch
+                candidates.addPragmaAndCallConvMismatch(wanted, got, c.config)
+              effectProblem(wanted, got, candidates, c)
 
-      of kUnknown: discard "do not break 'nim check'"
-      candidates.add "\n"
+        of kUnknown: discard "do not break 'nim check'"
+        candidates.add "\n"
       if err.firstMismatch.arg == 1 and nArg.kind == nkTupleConstr and
           n.kind == nkCommand:
         maybeWrongSpace = true
@@ -370,7 +415,6 @@ proc bracketNotFoundError(c: PContext; n: PNode) =
     notFoundError(c, n, errors)
 
 proc getMsgDiagnostic(c: PContext, flags: TExprFlags, n, f: PNode): string =
-  result = ""
   if c.compilesContextId > 0:
     # we avoid running more diagnostic when inside a `compiles(expr)`, to
     # errors while running diagnostic (see test D20180828T234921), and
@@ -406,9 +450,8 @@ proc resolveOverloads(c: PContext, n, orig: PNode,
                       filter: TSymKinds, flags: TExprFlags,
                       errors: var CandidateErrors,
                       errorsEnabled: bool): TCandidate =
-  result = default(TCandidate)
   var initialBinding: PNode
-  var alt: TCandidate = default(TCandidate)
+  var alt: TCandidate
   var f = n[0]
   if f.kind == nkBracketExpr:
     # fill in the bindings:
@@ -564,64 +607,8 @@ proc getCallLineInfo(n: PNode): TLineInfo =
     discard
   result = n.info
 
-proc inheritBindings(c: PContext, x: var TCandidate, expectedType: PType) =
-  ## Helper proc to inherit bound generic parameters from expectedType into x.
-  ## Does nothing if 'inferGenericTypes' isn't in c.features.
-  if inferGenericTypes notin c.features: return
-  if expectedType == nil or x.callee[0] == nil: return # required for inference
-
-  var
-    flatUnbound: seq[PType] = @[]
-    flatBound: seq[PType] = @[]
-  # seq[(result type, expected type)]
-  var typeStack = newSeq[(PType, PType)]()
-
-  template stackPut(a, b) =
-    ## skips types and puts the skipped version on stack
-    # It might make sense to skip here one by one. It's not part of the main
-    #  type reduction because the right side normally won't be skipped
-    const toSkip = { tyVar, tyLent, tyStatic, tyCompositeTypeClass, tySink }
-    let
-      x = a.skipTypes(toSkip)
-      y = if a.kind notin toSkip: b
-          else: b.skipTypes(toSkip)
-    typeStack.add((x, y))
-
-  stackPut(x.callee[0], expectedType)
-
-  while typeStack.len() > 0:
-    let (t, u) = typeStack.pop()
-    if t == u or t == nil or u == nil or t.kind == tyAnything or u.kind == tyAnything:
-      continue
-    case t.kind
-    of ConcreteTypes, tyGenericInvocation, tyUncheckedArray:
-      # nested, add all the types to stack
-      let
-        startIdx = if u.kind in ConcreteTypes: 0 else: 1
-        endIdx = min(u.len() - startIdx, t.len())
-
-      for i in startIdx ..< endIdx:
-        # early exit with current impl
-        if t[i] == nil or u[i] == nil: return
-        stackPut(t[i], u[i])
-    of tyGenericParam:
-      let prebound = x.bindings.idTableGet(t).PType
-      if prebound != nil:
-        continue # Skip param, already bound
-
-      # fully reduced generic param, bind it
-      if t notin flatUnbound:
-        flatUnbound.add(t)
-        flatBound.add(u)
-    else:
-      discard
-  # update bindings
-  for i in 0 ..< flatUnbound.len():
-    x.bindings.idTablePut(flatUnbound[i], flatBound[i])
-
-proc semResolvedCall(c: PContext, x: var TCandidate,
-                     n: PNode, flags: TExprFlags;
-                     expectedType: PType = nil): PNode =
+proc semResolvedCall(c: PContext, x: TCandidate,
+                     n: PNode, flags: TExprFlags): PNode =
   assert x.state == csMatch
   var finalCallee = x.calleeSym
   let info = getCallLineInfo(n)
@@ -641,12 +628,10 @@ proc semResolvedCall(c: PContext, x: var TCandidate,
       if x.calleeSym.magic in {mArrGet, mArrPut}:
         finalCallee = x.calleeSym
       else:
-        c.inheritBindings(x, expectedType)
         finalCallee = generateInstance(c, x.calleeSym, x.bindings, n.info)
     else:
       # For macros and templates, the resolved generic params
       # are added as normal params.
-      c.inheritBindings(x, expectedType)
       for s in instantiateGenericParamList(c, gp, x.bindings):
         case s.kind
         of skConst:
@@ -655,7 +640,12 @@ proc semResolvedCall(c: PContext, x: var TCandidate,
           else:
             x.call.add c.graph.emptyNode
         of skType:
-          x.call.add newSymNode(s, n.info)
+          var tn = newSymNode(s, n.info)
+          # this node will be used in template substitution,
+          # pretend this is an untyped node and let regular sem handle the type
+          # to prevent problems where a generic parameter is treated as a value
+          tn.typ = nil
+          x.call.add tn
         else:
           internalAssert c.config, false
 
@@ -675,8 +665,7 @@ proc tryDeref(n: PNode): PNode =
   result.add n
 
 proc semOverloadedCall(c: PContext, n, nOrig: PNode,
-                       filter: TSymKinds, flags: TExprFlags;
-                       expectedType: PType = nil): PNode =
+                       filter: TSymKinds, flags: TExprFlags): PNode =
   var errors: CandidateErrors = @[] # if efExplain in flags: @[] else: nil
   var r = resolveOverloads(c, n, nOrig, filter, flags, errors, efExplain in flags)
   if r.state == csMatch:
@@ -686,7 +675,7 @@ proc semOverloadedCall(c: PContext, n, nOrig: PNode,
       message(c.config, n.info, hintUserRaw,
               "Non-matching candidates for " & renderTree(n) & "\n" &
               candidates)
-    result = semResolvedCall(c, r, n, flags, expectedType)
+    result = semResolvedCall(c, r, n, flags)
   else:
     if efDetermineType in flags and c.inGenericContext > 0 and c.matchedConcept == nil:
       result = semGenericStmt(c, n)
@@ -696,10 +685,7 @@ proc semOverloadedCall(c: PContext, n, nOrig: PNode,
       # this time enabling all the diagnostic output (this should fail again)
       result = semOverloadedCall(c, n, nOrig, filter, flags + {efExplain})
     elif efNoUndeclared notin flags:
-      result = nil
       notFoundError(c, n, errors)
-    else:
-      result = nil
 
 proc explicitGenericInstError(c: PContext; n: PNode): PNode =
   localError(c.config, getCallLineInfo(n), errCannotInstantiateX % renderTree(n))
@@ -717,7 +703,8 @@ proc explicitGenericSym(c: PContext, n: PNode, s: PSym): PNode =
     if formal.kind == tyStatic and arg.kind != tyStatic:
       let evaluated = c.semTryConstExpr(c, n[i])
       if evaluated != nil:
-        arg = newTypeS(tyStatic, c, sons = @[evaluated.typ])
+        arg = newTypeS(tyStatic, c)
+        arg.sons = @[evaluated.typ]
         arg.n = evaluated
     let tm = typeRel(m, formal, arg)
     if tm in {isNone, isConvertible}: return nil
@@ -728,14 +715,18 @@ proc explicitGenericSym(c: PContext, n: PNode, s: PSym): PNode =
   onUse(info, s)
   result = newSymNode(newInst, info)
 
-proc explicitGenericInstantiation(c: PContext, n: PNode, s: PSym): PNode =
-  assert n.kind == nkBracketExpr
+proc setGenericParams(c: PContext, n: PNode) =
+  ## sems generic params in subscript expression
   for i in 1..<n.len:
     let e = semExprWithType(c, n[i])
     if e.typ == nil:
       n[i].typ = errorType(c)
     else:
       n[i].typ = e.typ.skipTypes({tyTypeDesc})
+
+proc explicitGenericInstantiation(c: PContext, n: PNode, s: PSym): PNode =
+  assert n.kind == nkBracketExpr
+  setGenericParams(c, n)
   var s = s
   var a = n[0]
   if a.kind == nkSym:
@@ -818,7 +809,7 @@ proc searchForBorrowProc(c: PContext, startScope: PScope, fn: PSym): tuple[s: PS
     if resolved != nil:
       result.s = resolved[0].sym
       result.state = bsMatch
-      if not compareTypes(result.s.typ[0], fn.typ[0], dcEqIgnoreDistinct):
+      if not compareTypes(result.s.typ[0], fn.typ[0], dcEqIgnoreDistinct, {IgnoreFlags}):
         result.state = bsReturnNotMatch
       elif result.s.magic in {mArrPut, mArrGet}:
         # cannot borrow these magics for now

compiler/semdata.nim

@@ -135,7 +135,7 @@ type
     semOperand*: proc (c: PContext, n: PNode, flags: TExprFlags = {}): PNode {.nimcall.}
     semConstBoolExpr*: proc (c: PContext, n: PNode): PNode {.nimcall.} # XXX bite the bullet
     semOverloadedCall*: proc (c: PContext, n, nOrig: PNode,
-                              filter: TSymKinds, flags: TExprFlags, expectedType: PType = nil): PNode {.nimcall.}
+                              filter: TSymKinds, flags: TExprFlags): PNode {.nimcall.}
     semTypeNode*: proc(c: PContext, n: PNode, prev: PType): PType {.nimcall.}
     semInferredLambda*: proc(c: PContext, pt: TIdTable, n: PNode): PNode
     semGenerateInstance*: proc (c: PContext, fn: PSym, pt: TIdTable,
@@ -168,7 +168,7 @@ type
     sideEffects*: Table[int, seq[(TLineInfo, PSym)]] # symbol.id index
     inUncheckedAssignSection*: int
     importModuleLookup*: Table[int, seq[int]] # (module.ident.id, [module.id])
-    skipTypes*: seq[PNode] # used to skip types between passes in type section. So far only used for inheritance and sets.
+    skipTypes*: seq[PNode] # used to skip types between passes in type section. So far only used for inheritance, sets and generic bodies.
   TBorrowState* = enum
     bsNone, bsReturnNotMatch, bsNoDistinct, bsGeneric, bsNotSupported, bsMatch
 
@@ -251,7 +251,7 @@ proc popProcCon*(c: PContext) {.inline.} = c.p = c.p.next
 
 proc put*(p: PProcCon; key, val: PSym) =
   if not p.mappingExists:
-    p.mapping = initIdTable()
+    initIdTable(p.mapping)
     p.mappingExists = true
   #echo "put into table ", key.info
   p.mapping.idTablePut(key, val)
@@ -317,13 +317,13 @@ proc newContext*(graph: ModuleGraph; module: PSym): PContext =
   result.converters = @[]
   result.patterns = @[]
   result.includedFiles = initIntSet()
-  result.pureEnumFields = initStrTable()
-  result.userPragmas = initStrTable()
+  initStrTable(result.pureEnumFields)
+  initStrTable(result.userPragmas)
   result.generics = @[]
   result.unknownIdents = initIntSet()
   result.cache = graph.cache
   result.graph = graph
-  result.signatures = initStrTable()
+  initStrTable(result.signatures)
   result.features = graph.config.features
   if graph.config.symbolFiles != disabledSf:
     let id = module.position
@@ -388,15 +388,15 @@ proc reexportSym*(c: PContext; s: PSym) =
 
 proc newLib*(kind: TLibKind): PLib =
   new(result)
-  result.kind = kind          #result.syms = initObjectSet()
+  result.kind = kind          #initObjectSet(result.syms)
 
 proc addToLib*(lib: PLib, sym: PSym) =
   #if sym.annex != nil and not isGenericRoutine(sym):
   #  LocalError(sym.info, errInvalidPragma)
   sym.annex = lib
 
-proc newTypeS*(kind: TTypeKind, c: PContext, sons: seq[PType] = @[]): PType =
-  result = newType(kind, nextTypeId(c.idgen), getCurrOwner(c), sons = sons)
+proc newTypeS*(kind: TTypeKind, c: PContext): PType =
+  result = newType(kind, nextTypeId(c.idgen), getCurrOwner(c))
 
 proc makePtrType*(owner: PSym, baseType: PType; idgen: IdGenerator): PType =
   result = newType(tyPtr, nextTypeId(idgen), owner)
@@ -446,15 +446,13 @@ proc makeTypeFromExpr*(c: PContext, n: PNode): PType =
 
 proc newTypeWithSons*(owner: PSym, kind: TTypeKind, sons: seq[PType];
                       idgen: IdGenerator): PType =
-  result = newType(kind, nextTypeId(idgen), owner, sons = sons)
+  result = newType(kind, nextTypeId(idgen), owner)
+  result.sons = sons
 
 proc newTypeWithSons*(c: PContext, kind: TTypeKind,
                       sons: seq[PType]): PType =
-  result = newType(kind, nextTypeId(c.idgen), getCurrOwner(c), sons = sons)
-
-proc newTypeWithSons*(c: PContext, kind: TTypeKind,
-                      parent: PType): PType =
-  result = newType(kind, nextTypeId(c.idgen), getCurrOwner(c), parent = parent)
+  result = newType(kind, nextTypeId(c.idgen), getCurrOwner(c))
+  result.sons = sons
 
 proc makeStaticExpr*(c: PContext, n: PNode): PNode =
   result = newNodeI(nkStaticExpr, n.info)
@@ -463,21 +461,21 @@ proc makeStaticExpr*(c: PContext, n: PNode): PNode =
                else: newTypeWithSons(c, tyStatic, @[n.typ])
 
 proc makeAndType*(c: PContext, t1, t2: PType): PType =
-  result = newTypeS(tyAnd, c, sons = @[t1, t2])
+  result = newTypeS(tyAnd, c)
+  result.sons = @[t1, t2]
   propagateToOwner(result, t1)
   propagateToOwner(result, t2)
   result.flags.incl((t1.flags + t2.flags) * {tfHasStatic})
   result.flags.incl tfHasMeta
 
 proc makeOrType*(c: PContext, t1, t2: PType): PType =
-  
+  result = newTypeS(tyOr, c)
   if t1.kind != tyOr and t2.kind != tyOr:
-    result = newTypeS(tyOr, c, sons = @[t1, t2])
+    result.sons = @[t1, t2]
   else:
-    result = newTypeS(tyOr, c)
     template addOr(t1) =
       if t1.kind == tyOr:
-        for x in t1: result.rawAddSon x
+        for x in t1.sons: result.rawAddSon x
       else:
         result.rawAddSon t1
     addOr(t1)
@@ -488,7 +486,8 @@ proc makeOrType*(c: PContext, t1, t2: PType): PType =
   result.flags.incl tfHasMeta
 
 proc makeNotType*(c: PContext, t1: PType): PType =
-  result = newTypeS(tyNot, c, sons = @[t1])
+  result = newTypeS(tyNot, c)
+  result.sons = @[t1]
   propagateToOwner(result, t1)
   result.flags.incl(t1.flags * {tfHasStatic})
   result.flags.incl tfHasMeta
@@ -499,7 +498,8 @@ proc nMinusOne(c: PContext; n: PNode): PNode =
 # Remember to fix the procs below this one when you make changes!
 proc makeRangeWithStaticExpr*(c: PContext, n: PNode): PType =
   let intType = getSysType(c.graph, n.info, tyInt)
-  result = newTypeS(tyRange, c, sons = @[intType])
+  result = newTypeS(tyRange, c)
+  result.sons = @[intType]
   if n.typ != nil and n.typ.n == nil:
     result.flags.incl tfUnresolved
   result.n = newTreeI(nkRange, n.info, newIntTypeNode(0, intType),

compiler/semexprs.nim

@@ -54,17 +54,6 @@ proc semOperand(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
   # same as 'semExprWithType' but doesn't check for proc vars
   result = semExpr(c, n, flags + {efOperand})
   if result.typ != nil:
-    # XXX tyGenericInst here?
-    if result.typ.kind == tyProc and hasUnresolvedParams(result, {efOperand}):
-      #and tfUnresolved in result.typ.flags:
-      let owner = result.typ.owner
-      let err =
-        # consistent error message with evaltempl/semMacroExpr
-        if owner != nil and owner.kind in {skTemplate, skMacro}:
-          errMissingGenericParamsForTemplate % n.renderTree
-        else:
-          errProcHasNoConcreteType % n.renderTree
-      localError(c.config, n.info, err)
     if result.typ.kind in {tyVar, tyLent}: result = newDeref(result)
   elif {efWantStmt, efAllowStmt} * flags != {}:
     result.typ = newTypeS(tyVoid, c)
@@ -92,7 +81,10 @@ proc semExprCheck(c: PContext, n: PNode, flags: TExprFlags, expectedType: PType
 
 proc ambiguousSymChoice(c: PContext, orig, n: PNode): PNode =
   let first = n[0].sym
-  if first.kind == skEnumField:
+  var foundSym: PSym = nil
+  if first.kind == skEnumField and
+      not isAmbiguous(c, first.name, {skEnumField}, foundSym) and
+      foundSym == first:
     # choose the first resolved enum field, i.e. the latest in scope
     # to mirror behavior before overloadable enums
     if hintAmbiguousEnum in c.config.notes:
@@ -389,7 +381,8 @@ proc semConv(c: PContext, n: PNode; flags: TExprFlags = {}, expectedType: PType
       elif op.kind in {nkPar, nkTupleConstr} and targetType.kind == tyTuple:
         op = fitNode(c, targetType, op, result.info)
     of convNotNeedeed:
-      message(c.config, n.info, hintConvFromXtoItselfNotNeeded, result.typ.typeToString)
+      if efNoSem2Check notin flags:
+        message(c.config, n.info, hintConvFromXtoItselfNotNeeded, result.typ.typeToString)
     of convNotLegal:
       result = fitNode(c, result.typ, result[1], result.info)
       if result == nil:
@@ -519,8 +512,9 @@ proc isOpImpl(c: PContext, n: PNode, flags: TExprFlags): PNode =
   result.typ = n.typ
 
 proc semIs(c: PContext, n: PNode, flags: TExprFlags): PNode =
-  if n.len != 3:
+  if n.len != 3 or n[2].kind == nkEmpty:
     localError(c.config, n.info, "'is' operator takes 2 arguments")
+    return errorNode(c, n)
 
   let boolType = getSysType(c.graph, n.info, tyBool)
   result = n
@@ -620,7 +614,7 @@ proc changeType(c: PContext; n: PNode, newType: PType, check: bool) =
           a.add m
           changeType(m, tup[i], check)
   of nkCharLit..nkUInt64Lit:
-    if check and n.kind != nkUInt64Lit and not sameType(n.typ, newType):
+    if check and n.kind != nkUInt64Lit and not sameTypeOrNil(n.typ, newType):
       let value = n.intVal
       if value < firstOrd(c.config, newType) or value > lastOrd(c.config, newType):
         localError(c.config, n.info, "cannot convert " & $value &
@@ -657,7 +651,7 @@ proc semArrayConstr(c: PContext, n: PNode, flags: TExprFlags; expectedType: PTyp
     else: discard
   rawAddSon(result.typ, nil)     # index type
   var
-    firstIndex, lastIndex: Int128 = Zero
+    firstIndex, lastIndex: Int128
     indexType = getSysType(c.graph, n.info, tyInt)
     lastValidIndex = lastOrd(c.config, indexType)
   if n.len == 0:
@@ -957,17 +951,17 @@ proc semStaticExpr(c: PContext, n: PNode; expectedType: PType = nil): PNode =
     result = fixupTypeAfterEval(c, result, a)
 
 proc semOverloadedCallAnalyseEffects(c: PContext, n: PNode, nOrig: PNode,
-                                     flags: TExprFlags; expectedType: PType = nil): PNode =
+                                     flags: TExprFlags): PNode =
   if flags*{efInTypeof, efWantIterator, efWantIterable} != {}:
     # consider: 'for x in pReturningArray()' --> we don't want the restriction
     # to 'skIterator' anymore; skIterator is preferred in sigmatch already
     # for typeof support.
     # for ``typeof(countup(1,3))``, see ``tests/ttoseq``.
     result = semOverloadedCall(c, n, nOrig,
-      {skProc, skFunc, skMethod, skConverter, skMacro, skTemplate, skIterator}, flags, expectedType)
+      {skProc, skFunc, skMethod, skConverter, skMacro, skTemplate, skIterator}, flags)
   else:
     result = semOverloadedCall(c, n, nOrig,
-      {skProc, skFunc, skMethod, skConverter, skMacro, skTemplate}, flags, expectedType)
+      {skProc, skFunc, skMethod, skConverter, skMacro, skTemplate}, flags)
 
   if result != nil:
     if result[0].kind != nkSym:
@@ -992,7 +986,6 @@ proc semOverloadedCallAnalyseEffects(c: PContext, n: PNode, nOrig: PNode,
 
 proc resolveIndirectCall(c: PContext; n, nOrig: PNode;
                          t: PType): TCandidate =
-  result = default(TCandidate)
   initCandidate(c, result, t)
   matches(c, n, nOrig, result)
 
@@ -1001,12 +994,34 @@ proc bracketedMacro(n: PNode): PSym =
     result = n[0].sym
     if result.kind notin {skMacro, skTemplate}:
       result = nil
-  else:
-    result = nil
 
-proc setGenericParams(c: PContext, n: PNode) =
-  for i in 1..<n.len:
-    n[i].typ = semTypeNode(c, n[i], nil)
+proc finishOperand(c: PContext, a: PNode): PNode =
+  if a.typ.isNil:
+    result = c.semOperand(c, a, {efDetermineType})
+  else:
+    result = a
+  # XXX tyGenericInst here?
+  if result.typ.kind == tyProc and hasUnresolvedParams(result, {efOperand}):
+    #and tfUnresolved in result.typ.flags:
+    let owner = result.typ.owner
+    let err =
+      # consistent error message with evaltempl/semMacroExpr
+      if owner != nil and owner.kind in {skTemplate, skMacro}:
+        errMissingGenericParamsForTemplate % a.renderTree
+      else:
+        errProcHasNoConcreteType % a.renderTree
+    localError(c.config, a.info, err)
+  considerGenSyms(c, result)
+
+proc semFinishOperands(c: PContext; n: PNode; isBracketExpr = false) =
+  # this needs to be called to ensure that after overloading resolution every
+  # argument has been sem'checked
+
+  # skip the first argument for operands of `[]` since it may be an unresolved
+  # generic proc, which is handled in semMagic
+  let start = 1 + ord(isBracketExpr)
+  for i in start..<n.len:
+    n[i] = finishOperand(c, n[i])
 
 proc afterCallActions(c: PContext; n, orig: PNode, flags: TExprFlags; expectedType: PType = nil): PNode =
   if efNoSemCheck notin flags and n.typ != nil and n.typ.kind == tyError:
@@ -1028,7 +1043,7 @@ proc afterCallActions(c: PContext; n, orig: PNode, flags: TExprFlags; expectedTy
   of skMacro: result = semMacroExpr(c, result, orig, callee, flags, expectedType)
   of skTemplate: result = semTemplateExpr(c, result, callee, flags, expectedType)
   else:
-    semFinishOperands(c, result)
+    semFinishOperands(c, result, isBracketExpr = callee.magic in {mArrGet, mArrPut})
     activate(c, result)
     fixAbstractType(c, result)
     analyseIfAddressTakenInCall(c, result)
@@ -1114,7 +1129,6 @@ proc semIndirectOp(c: PContext, n: PNode, flags: TExprFlags; expectedType: PType
           msg.addDeclaredLocMaybe(c.config, typ)
           localError(c.config, n.info, msg)
         return errorNode(c, n)
-      result = nil
     else:
       result = m.call
       instGenericConvertersSons(c, result, m)
@@ -1146,7 +1160,7 @@ proc semDirectOp(c: PContext, n: PNode, flags: TExprFlags; expectedType: PType =
   # this seems to be a hotspot in the compiler!
   let nOrig = n.copyTree
   #semLazyOpAux(c, n)
-  result = semOverloadedCallAnalyseEffects(c, n, nOrig, flags, expectedType)
+  result = semOverloadedCallAnalyseEffects(c, n, nOrig, flags)
   if result != nil: result = afterCallActions(c, result, nOrig, flags, expectedType)
   else: result = errorNode(c, n)
 
@@ -1287,7 +1301,6 @@ proc readTypeParameter(c: PContext, typ: PType,
   return nil
 
 proc semSym(c: PContext, n: PNode, sym: PSym, flags: TExprFlags): PNode =
-  result = nil
   assert n.kind in nkIdentKinds + {nkDotExpr}
   let s = getGenSym(c, sym)
   case s.kind
@@ -1412,10 +1425,9 @@ proc tryReadingGenericParam(c: PContext, n: PNode, i: PIdent, t: PType): PNode =
     n.typ = makeTypeFromExpr(c, copyTree(n))
     result = n
   else:
-    result = nil
+    discard
 
 proc tryReadingTypeField(c: PContext, n: PNode, i: PIdent, ty: PType): PNode =
-  result = nil
   var ty = ty.skipTypes(tyDotOpTransparent)
   case ty.kind
   of tyEnum:
@@ -1424,7 +1436,7 @@ proc tryReadingTypeField(c: PContext, n: PNode, i: PIdent, ty: PType): PNode =
     while ty != nil:
       f = getSymFromList(ty.n, i)
       if f != nil: break
-      ty = ty[0]         # enum inheritance
+      ty = ty.sons[0]         # enum inheritance
     if f != nil:
       result = newSymNode(f)
       result.info = n.info
@@ -1613,7 +1625,6 @@ proc maybeInstantiateGeneric(c: PContext, n: PNode, s: PSym): PNode =
 proc semSubscript(c: PContext, n: PNode, flags: TExprFlags): PNode =
   ## returns nil if not a built-in subscript operator; also called for the
   ## checking of assignments
-  result = nil
   if n.len == 1:
     let x = semDeref(c, n)
     if x == nil: return nil
@@ -1828,6 +1839,39 @@ proc goodLineInfo(arg: PNode): TLineInfo =
   else:
     arg.info
 
+proc makeTupleAssignments(c: PContext; n: PNode): PNode =
+  ## expand tuple unpacking assignment into series of assignments
+  ## 
+  ## mirrored with semstmts.makeVarTupleSection
+  let lhs = n[0]
+  let value = semExprWithType(c, n[1], {efTypeAllowed})
+  if value.typ.kind != tyTuple:
+    localError(c.config, n[1].info, errTupleUnpackingTupleExpected %
+      [typeToString(value.typ, preferDesc)])
+  elif lhs.len != value.typ.len:
+    localError(c.config, n.info, errTupleUnpackingDifferentLengths %
+      [$lhs.len, typeToString(value.typ, preferDesc), $value.typ.len])
+  result = newNodeI(nkStmtList, n.info)
+
+  let temp = newSym(skTemp, getIdent(c.cache, "tmpTupleAsgn"), c.idgen, getCurrOwner(c), n.info)
+  temp.typ = value.typ
+  temp.flags.incl(sfGenSym)
+  var v = newNodeI(nkLetSection, value.info)
+  let tempNode = newSymNode(temp) #newIdentNode(getIdent(genPrefix & $temp.id), value.info)
+  var vpart = newNodeI(nkIdentDefs, v.info, 3)
+  vpart[0] = tempNode
+  vpart[1] = c.graph.emptyNode
+  vpart[2] = value
+  v.add vpart
+  result.add(v)
+
+  for i in 0..<lhs.len:
+    if lhs[i].kind == nkIdent and lhs[i].ident.id == ord(wUnderscore):
+      # skip _ assignments if we are using a temp as they are already evaluated
+      discard
+    else:
+      result.add newAsgnStmt(lhs[i], newTupleAccessRaw(tempNode, i))
+
 proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
   checkSonsLen(n, 2, c.config)
   var a = n[0]
@@ -1856,7 +1900,7 @@ proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
       result.add(n[1])
       if mode == noOverloadedSubscript:
         bracketNotFoundError(c, result)
-        return n
+        return errorNode(c, n)
       else:
         result = semExprNoType(c, result)
         return result
@@ -1870,7 +1914,7 @@ proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
       # unfortunately we need to rewrite ``(x, y) = foo()`` already here so
       # that overloading of the assignment operator still works. Usually we
       # prefer to do these rewritings in transf.nim:
-      return semStmt(c, lowerTupleUnpackingForAsgn(c.graph, n, c.idgen, c.p.owner), {})
+      return semStmt(c, makeTupleAssignments(c, n), {})
     else:
       a = semExprWithType(c, a, {efLValue})
   else:
@@ -2119,6 +2163,7 @@ proc expectString(c: PContext, n: PNode): string =
   if n.kind in nkStrKinds:
     return n.strVal
   else:
+    result = ""
     localError(c.config, n.info, errStringLiteralExpected)
 
 proc newAnonSym(c: PContext; kind: TSymKind, info: TLineInfo): PSym =
@@ -2255,7 +2300,7 @@ proc semQuoteAst(c: PContext, n: PNode): PNode =
     for i in 1..<ids.len:
       let exp = semExprWithType(c, quotes[i+1], {})
       let typ = exp.typ
-      if tfTriggersCompileTime notin typ.flags and exp.kind == nkSym and exp.sym.kind notin routineKinds + {skType}:
+      if tfTriggersCompileTime notin typ.flags and typ.kind != tyStatic and exp.kind == nkSym and exp.sym.kind notin routineKinds + {skType}:
         dummyTemplate[paramsPos].add newTreeI(nkIdentDefs, n.info, ids[i], newNodeIT(nkType, n.info, typ), c.graph.emptyNode)
       else:
         dummyTemplate[paramsPos].add newTreeI(nkIdentDefs, n.info, ids[i], getSysSym(c.graph, n.info, "typed").newSymNode, c.graph.emptyNode)
@@ -2314,7 +2359,7 @@ proc tryExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
     if c.config.errorCounter != oldErrorCount:
       result = nil
   except ERecoverableError:
-    result = nil
+    discard
   # undo symbol table changes (as far as it's possible):
   c.compilesContextId = oldCompilesId
   c.generics = oldGenerics
@@ -2363,7 +2408,8 @@ proc instantiateCreateFlowVarCall(c: PContext; t: PType;
   let sym = magicsys.getCompilerProc(c.graph, "nimCreateFlowVar")
   if sym == nil:
     localError(c.config, info, "system needs: nimCreateFlowVar")
-  var bindings: TIdTable = initIdTable()
+  var bindings: TIdTable
+  initIdTable(bindings)
   bindings.idTablePut(sym.ast[genericParamsPos][0].typ, t)
   result = c.semGenerateInstance(c, sym, bindings, info)
   # since it's an instantiation, we unmark it as a compilerproc. Otherwise
@@ -2522,9 +2568,10 @@ proc semWhen(c: PContext, n: PNode, semCheck = true): PNode =
   # If semCheck is set to false, ``when`` will return the verbatim AST of
   # the correct branch. Otherwise the AST will be passed through semStmt.
   result = nil
+  let flags = if semCheck: {efWantStmt} else: {}
 
   template setResult(e: untyped) =
-    if semCheck: result = semExpr(c, e) # do not open a new scope!
+    if semCheck: result = semExpr(c, e, flags) # do not open a new scope!
     else: result = e
 
   # Check if the node is "when nimvm"
@@ -2550,7 +2597,7 @@ proc semWhen(c: PContext, n: PNode, semCheck = true): PNode =
       checkSonsLen(it, 2, c.config)
       if whenNimvm:
         if semCheck:
-          it[1] = semExpr(c, it[1])
+          it[1] = semExpr(c, it[1], flags)
           typ = commonType(c, typ, it[1].typ)
         result = n # when nimvm is not elimited until codegen
       else:
@@ -2566,7 +2613,7 @@ proc semWhen(c: PContext, n: PNode, semCheck = true): PNode =
       checkSonsLen(it, 1, c.config)
       if result == nil or whenNimvm:
         if semCheck:
-          it[0] = semExpr(c, it[0])
+          it[0] = semExpr(c, it[0], flags)
           typ = commonType(c, typ, it[0].typ)
         if result == nil:
           result = it[0]
@@ -2829,7 +2876,7 @@ proc semExport(c: PContext, n: PNode): PNode =
 
 proc semTupleConstr(c: PContext, n: PNode, flags: TExprFlags; expectedType: PType = nil): PNode =
   var tupexp = semTuplePositionsConstr(c, n, flags, expectedType)
-  var isTupleType: bool = false
+  var isTupleType: bool
   if tupexp.len > 0: # don't interpret () as type
     isTupleType = tupexp[0].typ.kind == tyTypeDesc
     # check if either everything or nothing is tyTypeDesc
@@ -2844,7 +2891,6 @@ proc semTupleConstr(c: PContext, n: PNode, flags: TExprFlags; expectedType: PTyp
     result = tupexp
 
 proc shouldBeBracketExpr(n: PNode): bool =
-  result = false
   assert n.kind in nkCallKinds
   let a = n[0]
   if a.kind in nkCallKinds:
@@ -2862,8 +2908,6 @@ proc asBracketExpr(c: PContext; n: PNode): PNode =
     if n.kind in {nkIdent, nkAccQuoted}:
       let s = qualifiedLookUp(c, n, {})
       result = s != nil and isGenericRoutineStrict(s)
-    else:
-      result = false
 
   assert n.kind in nkCallKinds
   if n.len > 1 and isGeneric(c, n[1]):
@@ -2876,6 +2920,18 @@ proc asBracketExpr(c: PContext; n: PNode): PNode =
           return result
   return nil
 
+proc isOpenArraySym(x: PNode): bool =
+  var x = x
+  while true:
+    case x.kind
+    of {nkAddr, nkHiddenAddr}:
+      x = x[0]
+    of {nkHiddenStdConv, nkHiddenDeref}:
+      x = x[1]
+    else:
+      break
+  result = x.kind == nkSym
+
 proc hoistParamsUsedInDefault(c: PContext, call, letSection, defExpr: var PNode) =
   # This takes care of complicated signatures such as:
   # proc foo(a: int, b = a)
@@ -2896,7 +2952,10 @@ proc hoistParamsUsedInDefault(c: PContext, call, letSection, defExpr: var PNode)
   if defExpr.kind == nkSym and defExpr.sym.kind == skParam and defExpr.sym.owner == call[0].sym:
     let paramPos = defExpr.sym.position + 1
 
-    if call[paramPos].kind != nkSym:
+    if call[paramPos].skipAddr.kind != nkSym and not (
+      skipTypes(call[paramPos].typ, abstractVar).kind in {tyOpenArray, tyVarargs} and
+      isOpenArraySym(call[paramPos])
+    ):
       let hoistedVarSym = newSym(skLet, getIdent(c.graph.cache, genPrefix), c.idgen,
                                  c.p.owner, letSection.info, c.p.owner.options)
       hoistedVarSym.typ = call[paramPos].typ
@@ -2922,7 +2981,7 @@ proc getNilType(c: PContext): PType =
     result.align = c.config.target.ptrSize.int16
     c.nilTypeCache = result
 
-proc enumFieldSymChoice(c: PContext, n: PNode, s: PSym): PNode =
+proc enumFieldSymChoice(c: PContext, n: PNode, s: PSym; flags: TExprFlags): PNode =
   var o: TOverloadIter
   var i = 0
   var a = initOverloadIter(o, c, n)
@@ -2935,7 +2994,7 @@ proc enumFieldSymChoice(c: PContext, n: PNode, s: PSym): PNode =
   if i <= 1:
     if sfGenSym notin s.flags:
       result = newSymNode(s, info)
-      markUsed(c, info, s)
+      markUsed(c, info, s, efInCall notin flags)
       onUse(info, s)
     else:
       result = n
@@ -2993,7 +3052,7 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType
   if nfSem in n.flags: return
   case n.kind
   of nkIdent, nkAccQuoted:
-    var s: PSym = nil
+    var s: PSym
     if expectedType != nil and (
         let expected = expectedType.skipTypes(abstractRange-{tyDistinct});
         expected.kind == tyEnum):
@@ -3025,7 +3084,7 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType
       if optOwnedRefs in c.config.globalOptions:
         result.typ = makeVarType(c, result.typ, tyOwned)
     of skEnumField:
-      result = enumFieldSymChoice(c, n, s)
+      result = enumFieldSymChoice(c, n, s, flags)
     else:
       result = semSym(c, n, s, flags)
     if expectedType != nil and isSymChoice(result):
@@ -3033,9 +3092,32 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType
       if result.kind == nkSym:
         result = semSym(c, result, result.sym, flags)
   of nkSym:
+    let s = n.sym
+    if nfOpenSym in n.flags:
+      let id = newIdentNode(s.name, n.info)
+      c.isAmbiguous = false
+      let s2 = qualifiedLookUp(c, id, {})
+      if s2 != nil and s2 != s and not c.isAmbiguous:
+        # only consider symbols defined under current proc:
+        var o = s2.owner
+        while o != nil:
+          if o == c.p.owner:
+            if genericsOpenSym in c.features:
+              result = semExpr(c, id, flags, expectedType)
+              return
+            else:
+              message(c.config, n.info, warnGenericsIgnoredInjection,
+                "a new symbol '" & s.name.s & "' has been injected during " &
+                "instantiation of " & c.p.owner.name.s & ", " &
+                "however " & getSymRepr(c.config, s) & " captured at " &
+                "the proc declaration will be used instead; " &
+                "either enable --experimental:genericsOpenSym to use the " &
+                "injected symbol or `bind` this captured symbol explicitly")
+              break
+          o = o.owner
     # because of the changed symbol binding, this does not mean that we
     # don't have to check the symbol for semantics here again!
-    result = semSym(c, n, n.sym, flags)
+    result = semSym(c, n, s, flags)
   of nkEmpty, nkNone, nkCommentStmt, nkType:
     discard
   of nkNilLit:
@@ -3053,7 +3135,6 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType
           expected.kind in {tyInt..tyInt64,
             tyUInt..tyUInt64,
             tyFloat..tyFloat128}):
-        result.typ = expected
         if expected.kind in {tyFloat..tyFloat128}:
           n.transitionIntToFloatKind(nkFloatLit)
         changeType(c, result, expectedType, check=true)
@@ -3133,7 +3214,7 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType
         elif s.magic == mNone: result = semDirectOp(c, n, flags, expectedType)
         else: result = semMagic(c, n, s, flags, expectedType)
       of skProc, skFunc, skMethod, skConverter, skIterator:
-        if s.magic == mNone: result = semDirectOp(c, n, flags, expectedType)
+        if s.magic == mNone: result = semDirectOp(c, n, flags)
         else: result = semMagic(c, n, s, flags, expectedType)
       else:
         #liMessage(n.info, warnUser, renderTree(n));

compiler/semfold.nim

@@ -65,34 +65,24 @@ proc foldAdd(a, b: Int128, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode
   let res = a + b
   if checkInRange(g.config, n, res):
     result = newIntNodeT(res, n, idgen, g)
-  else:
-    result = nil
 
 proc foldSub(a, b: Int128, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode =
   let res = a - b
   if checkInRange(g.config, n, res):
     result = newIntNodeT(res, n, idgen, g)
-  else:
-    result = nil
 
 proc foldUnarySub(a: Int128, n: PNode; idgen: IdGenerator, g: ModuleGraph): PNode =
   if a != firstOrd(g.config, n.typ):
     result = newIntNodeT(-a, n, idgen, g)
-  else:
-    result = nil
 
 proc foldAbs(a: Int128, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode =
   if a != firstOrd(g.config, n.typ):
     result = newIntNodeT(abs(a), n, idgen, g)
-  else:
-    result = nil
 
 proc foldMul(a, b: Int128, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode =
   let res = a * b
   if checkInRange(g.config, n, res):
     return newIntNodeT(res, n, idgen, g)
-  else:
-    result = nil
 
 proc ordinalValToString*(a: PNode; g: ModuleGraph): string =
   # because $ has the param ordinal[T], `a` is not necessarily an enum, but an
@@ -104,7 +94,6 @@ proc ordinalValToString*(a: PNode; g: ModuleGraph): string =
   of tyChar:
     result = $chr(toInt64(x) and 0xff)
   of tyEnum:
-    result = ""
     var n = t.n
     for i in 0..<n.len:
       if n[i].kind != nkSym: internalError(g.config, a.info, "ordinalValToString")
@@ -241,7 +230,13 @@ proc evalOp(m: TMagic, n, a, b, c: PNode; idgen: IdGenerator; g: ModuleGraph): P
   of mMulF64: result = newFloatNodeT(getFloat(a) * getFloat(b), n, g)
   of mDivF64:
     result = newFloatNodeT(getFloat(a) / getFloat(b), n, g)
-  of mIsNil: result = newIntNodeT(toInt128(ord(a.kind == nkNilLit)), n, idgen, g)
+  of mIsNil:
+    let val = a.kind == nkNilLit or
+      # nil closures have the value (nil, nil)
+      (a.typ != nil and skipTypes(a.typ, abstractRange).kind == tyProc and
+        a.kind == nkTupleConstr and a.len == 2 and
+        a[0].kind == nkNilLit and a[1].kind == nkNilLit)
+    result = newIntNodeT(toInt128(ord(val)), n, idgen, g)
   of mLtI, mLtB, mLtEnum, mLtCh:
     result = newIntNodeT(toInt128(ord(getOrdValue(a) < getOrdValue(b))), n, idgen, g)
   of mLeI, mLeB, mLeEnum, mLeCh:
@@ -357,7 +352,7 @@ proc magicCall(m: PSym, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode =
 
   var s = n[0].sym
   var a = getConstExpr(m, n[1], idgen, g)
-  var b, c: PNode = nil
+  var b, c: PNode
   if a == nil: return
   if n.len > 2:
     b = getConstExpr(m, n[2], idgen, g)
@@ -407,8 +402,7 @@ proc foldConv(n, a: PNode; idgen: IdGenerator; g: ModuleGraph; check = false): P
     of tyBool, tyEnum: # xxx shouldn't we disallow `tyEnum`?
       result = a
       result.typ = n.typ
-    else:
-      raiseAssert $srcTyp.kind
+    else: doAssert false, $srcTyp.kind
   of tyInt..tyInt64, tyUInt..tyUInt64:
     case srcTyp.kind
     of tyFloat..tyFloat64:
@@ -432,7 +426,7 @@ proc foldConv(n, a: PNode; idgen: IdGenerator; g: ModuleGraph; check = false): P
       result = a
       result.typ = n.typ
   of tyOpenArray, tyVarargs, tyProc, tyPointer:
-    result = nil
+    discard
   else:
     result = a
     result.typ = n.typ
@@ -459,25 +453,21 @@ proc foldArrayAccess(m: PSym, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNo
       result = x.sons[idx]
       if result.kind == nkExprColonExpr: result = result[1]
     else:
-      result = nil
       localError(g.config, n.info, formatErrorIndexBound(idx, x.len-1) & $n)
   of nkBracket:
     idx -= toInt64(firstOrd(g.config, x.typ))
     if idx >= 0 and idx < x.len: result = x[int(idx)]
-    else:
-      result = nil
-      localError(g.config, n.info, formatErrorIndexBound(idx, x.len-1) & $n)
+    else: localError(g.config, n.info, formatErrorIndexBound(idx, x.len-1) & $n)
   of nkStrLit..nkTripleStrLit:
     result = newNodeIT(nkCharLit, x.info, n.typ)
     if idx >= 0 and idx < x.strVal.len:
       result.intVal = ord(x.strVal[int(idx)])
     else:
       localError(g.config, n.info, formatErrorIndexBound(idx, x.strVal.len-1) & $n)
-  else: result = nil
+  else: discard
 
 proc foldFieldAccess(m: PSym, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode =
   # a real field access; proc calls have already been transformed
-  result = nil
   if n[1].kind != nkSym: return nil
   var x = getConstExpr(m, n[0], idgen, g)
   if x == nil or x.kind notin {nkObjConstr, nkPar, nkTupleConstr}: return
@@ -512,7 +502,6 @@ proc newSymNodeTypeDesc*(s: PSym; idgen: IdGenerator; info: TLineInfo): PNode =
     result.typ = s.typ
 
 proc foldDefine(m, s: PSym, n: PNode; idgen: IdGenerator; g: ModuleGraph): PNode =
-  result = nil
   var name = s.name.s
   let prag = extractPragma(s)
   if prag != nil:

compiler/semgnrc.nim

@@ -56,10 +56,12 @@ template isMixedIn(sym): bool =
                                s.magic == mNone and
                                s.kind in OverloadableSyms)
 
+template canOpenSym(s): bool =
+  {withinMixin, withinConcept} * flags == {withinMixin} and s.id notin ctx.toBind
+
 proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym,
                           ctx: var GenericCtx; flags: TSemGenericFlags,
                           fromDotExpr=false): PNode =
-  result = nil
   semIdeForTemplateOrGenericCheck(c.config, n, ctx.cursorInBody)
   incl(s.flags, sfUsed)
   template maybeDotChoice(c: PContext, n: PNode, s: PSym, fromDotExpr: bool) =
@@ -69,6 +71,9 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym,
         result.transitionSonsKind(nkClosedSymChoice)
     else:
       result = symChoice(c, n, s, scOpen)
+      if result.kind == nkSym and canOpenSym(result.sym):
+        result.flags.incl nfOpenSym
+        result.typ = nil
   case s.kind
   of skUnknown:
     # Introduced in this pass! Leave it as an identifier.
@@ -96,6 +101,9 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym,
         result = n
     else:
       result = newSymNodeTypeDesc(s, c.idgen, n.info)
+      if canOpenSym(result.sym):
+        result.flags.incl nfOpenSym
+        result.typ = nil
     onUse(n.info, s)
   of skParam:
     result = n
@@ -104,11 +112,17 @@ proc semGenericStmtSymbol(c: PContext, n: PNode, s: PSym,
     if (s.typ != nil) and
        (s.typ.flags * {tfGenericTypeParam, tfImplicitTypeParam} == {}):
       result = newSymNodeTypeDesc(s, c.idgen, n.info)
+      if canOpenSym(result.sym):
+        result.flags.incl nfOpenSym
+        result.typ = nil
     else:
       result = n
     onUse(n.info, s)
   else:
     result = newSymNode(s, n.info)
+    if canOpenSym(result.sym):
+      result.flags.incl nfOpenSym
+      result.typ = nil
     onUse(n.info, s)
 
 proc lookup(c: PContext, n: PNode, flags: TSemGenericFlags,
@@ -148,6 +162,7 @@ proc fuzzyLookup(c: PContext, n: PNode, flags: TSemGenericFlags,
 
   var s = qualifiedLookUp(c, n, luf)
   if s != nil:
+    isMacro = s.kind in {skTemplate, skMacro}
     result = semGenericStmtSymbol(c, n, s, ctx, flags)
   else:
     n[0] = semGenericStmt(c, n[0], flags, ctx)
@@ -188,6 +203,18 @@ proc addTempDecl(c: PContext; n: PNode; kind: TSymKind) =
   styleCheckDef(c, n.info, s, kind)
   onDef(n.info, s)
 
+proc addTempDeclToIdents(c: PContext; n: PNode; kind: TSymKind; inCall: bool) =
+  case n.kind 
+  of nkIdent:
+    if inCall:
+      addTempDecl(c, n, kind)
+  of nkCallKinds:
+    for s in n:
+      addTempDeclToIdents(c, s, kind, true)  
+  else:
+    for s in n:
+      addTempDeclToIdents(c, s, kind, inCall)
+
 proc semGenericStmt(c: PContext, n: PNode,
                     flags: TSemGenericFlags, ctx: var GenericCtx): PNode =
   result = n
@@ -360,7 +387,9 @@ proc semGenericStmt(c: PContext, n: PNode,
       var a = n[i]
       checkMinSonsLen(a, 1, c.config)
       for j in 0..<a.len-1:
-        a[j] = semGenericStmt(c, a[j], flags, ctx)
+        a[j] = semGenericStmt(c, a[j], flags+{withinMixin}, ctx)
+        addTempDeclToIdents(c, a[j], skVar, false)
+
       a[^1] = semGenericStmtScope(c, a[^1], flags, ctx)
     closeScope(c)
   of nkForStmt, nkParForStmt:
@@ -451,14 +480,53 @@ proc semGenericStmt(c: PContext, n: PNode,
       if n[0].kind != nkEmpty:
         n[0] = semGenericStmt(c, n[0], flags+{withinTypeDesc}, ctx)
       for i in 1..<n.len:
-        var a: PNode = nil
+        var a: PNode
         case n[i].kind
         of nkEnumFieldDef: a = n[i][0]
         of nkIdent: a = n[i]
         else: illFormedAst(n, c.config)
         addDecl(c, newSymS(skUnknown, getIdentNode(c, a), c))
-  of nkObjectTy, nkTupleTy, nkTupleClassTy:
-    discard
+  of nkTupleTy:
+    for i in 0..<n.len:
+      var a = n[i]
+      case a.kind:
+      of nkCommentStmt, nkNilLit, nkSym, nkEmpty: continue
+      of nkIdentDefs:
+        checkMinSonsLen(a, 3, c.config)
+        a[^2] = semGenericStmt(c, a[^2], flags+{withinTypeDesc}, ctx)
+        a[^1] = semGenericStmt(c, a[^1], flags, ctx)
+        for j in 0..<a.len-2:
+          addTempDecl(c, getIdentNode(c, a[j]), skField)
+      else:
+        illFormedAst(a, c.config)
+  of nkObjectTy:
+    if n.len > 0:
+      openScope(c)
+      for i in 0..<n.len:
+        result[i] = semGenericStmt(c, n[i], flags, ctx)
+      closeScope(c)
+  of nkRecList:
+    for i in 0..<n.len:
+      var a = n[i]
+      case a.kind:
+      of nkCommentStmt, nkNilLit, nkSym, nkEmpty: continue
+      of nkIdentDefs:
+        checkMinSonsLen(a, 3, c.config)
+        a[^2] = semGenericStmt(c, a[^2], flags+{withinTypeDesc}, ctx)
+        a[^1] = semGenericStmt(c, a[^1], flags, ctx)
+        for j in 0..<a.len-2:
+          addTempDecl(c, getIdentNode(c, a[j]), skField)
+      of nkRecCase, nkRecWhen:
+        n[i] = semGenericStmt(c, a, flags, ctx)
+      else:
+        illFormedAst(a, c.config)
+  of nkRecCase:
+    checkSonsLen(n[0], 3, c.config)
+    n[0][^2] = semGenericStmt(c, n[0][^2], flags+{withinTypeDesc}, ctx)
+    n[0][^1] = semGenericStmt(c, n[0][^1], flags, ctx)
+    addTempDecl(c, getIdentNode(c, n[0][0]), skField)
+    for i in 1..<n.len:
+      n[i] = semGenericStmt(c, n[i], flags, ctx)
   of nkFormalParams:
     checkMinSonsLen(n, 1, c.config)
     for i in 1..<n.len: