make case-object transitions explicit, make unknownLineInfo a const, …

…replace a few magic numbers with consts (#13170)

compiler/ast.nim

@@ -1020,6 +1020,10 @@ const
   skProcKinds* = {skProc, skFunc, skTemplate, skMacro, skIterator,
                   skMethod, skConverter}
 
+  defaultSize = -1
+  defaultAlignment = -1
+  defaultOffset = -1
+
 var ggDebug* {.deprecated.}: bool ## convenience switch for trying out things
 #var
 #  gMainPackageId*: int
@@ -1066,12 +1070,7 @@ when defined(useNodeIds):
   var gNodeId: int
 
 proc newNode*(kind: TNodeKind): PNode =
-  new(result)
-  result.kind = kind
-  #result.info = UnknownLineInfo() inlined:
-  result.info.fileIndex = InvalidFileIdx
-  result.info.col = int16(-1)
-  result.info.line = uint16(0)
+  result = PNode(kind: kind, info: unknownLineInfo)
   when defined(useNodeIds):
     result.id = gNodeId
     if result.id == nodeIdToDebug:
@@ -1091,15 +1090,8 @@ template previouslyInferred*(t: PType): PType =
 proc newSym*(symKind: TSymKind, name: PIdent, owner: PSym,
              info: TLineInfo; options: TOptions = {}): PSym =
   # generates a symbol and initializes the hash field too
-  new(result)
-  result.name = name
-  result.kind = symKind
-  result.flags = {}
-  result.info = info
-  result.options = options
-  result.owner = owner
-  result.offset = -1
-  result.id = getID()
+  result = PSym(name: name, kind: symKind, flags: {}, info: info, id: getID(),
+                options: options, owner: owner, offset: defaultOffset)
   when debugIds:
     registerId(result)
 
@@ -1193,9 +1185,7 @@ proc newSymNode*(sym: PSym, info: TLineInfo): PNode =
   result.info = info
 
 proc newNodeI*(kind: TNodeKind, info: TLineInfo): PNode =
-  new(result)
-  result.kind = kind
-  result.info = info
+  result = PNode(kind: kind, info: info)
   when defined(useNodeIds):
     result.id = gNodeId
     if result.id == nodeIdToDebug:
@@ -1204,9 +1194,7 @@ proc newNodeI*(kind: TNodeKind, info: TLineInfo): PNode =
     inc gNodeId
 
 proc newNodeI*(kind: TNodeKind, info: TLineInfo, children: int): PNode =
-  new(result)
-  result.kind = kind
-  result.info = info
+  result = PNode(kind: kind, info: info)
   if children > 0:
     newSeq(result.sons, children)
   when defined(useNodeIds):
@@ -1217,12 +1205,9 @@ proc newNodeI*(kind: TNodeKind, info: TLineInfo, children: int): PNode =
     inc gNodeId
 
 proc newNode*(kind: TNodeKind, info: TLineInfo, sons: TNodeSeq = @[],
-             typ: PType = nil): PNode =
-  new(result)
-  result.kind = kind
-  result.info = info
-  result.typ = typ
+              typ: PType = nil): PNode =
   # XXX use shallowCopy here for ownership transfer:
+  result = PNode(kind: kind, info: info, typ: typ)
   result.sons = sons
   when defined(useNodeIds):
     result.id = gNodeId
@@ -1321,14 +1306,10 @@ proc `$`*(s: PSym): string =
     result = "<nil>"
 
 proc newType*(kind: TTypeKind, owner: PSym): PType =
-  new(result)
-  result.kind = kind
-  result.owner = owner
-  result.size = -1
-  result.align = -1            # default alignment
-  result.id = getID()
-  result.uniqueId = result.id
-  result.lockLevel = UnspecifiedLockLevel
+  let id = getID()
+  result = PType(kind: kind, owner: owner, size: defaultSize,
+                 align: defaultAlignment, id: id, uniqueId: id,
+                 lockLevel: UnspecifiedLockLevel)
   when debugIds:
     registerId(result)
   when false:
@@ -1543,6 +1524,51 @@ proc copyNode*(src: PNode): PNode =
   of nkStrLit..nkTripleStrLit: result.strVal = src.strVal
   else: discard
 
+template transitionNodeKindCommon(k: TNodeKind) =
+  let obj {.inject.} = n[]
+  n[] = TNode(kind: k, typ: obj.typ, info: obj.info, flags: obj.flags,
+              comment: obj.comment)
+  when defined(useNodeIds):
+    n.id = obj.id
+
+proc transitionSonsKind*(n: PNode, kind: range[nkComesFrom..nkTupleConstr]) =
+  transitionNodeKindCommon(kind)
+  n.sons = obj.sons
+
+proc transitionIntKind*(n: PNode, kind: range[nkCharLit..nkUInt64Lit]) =
+  transitionNodeKindCommon(kind)
+  n.intVal = obj.intVal
+
+proc transitionNoneToSym*(n: PNode) =
+  transitionNodeKindCommon(nkSym)
+
+template transitionSymKindCommon*(k: TSymKind) =
+  let obj {.inject.} = s[]
+  s[] = TSym(kind: k, id: obj.id, magic: obj.magic, typ: obj.typ, name: obj.name,
+             info: obj.info, owner: obj.owner, flags: obj.flags, ast: obj.ast,
+             options: obj.options, position: obj.position, offset: obj.offset,
+             loc: obj.loc, annex: obj.annex, constraint: obj.constraint)
+  when hasFFI:
+    s.cname = obj.cname
+  when defined(nimsuggest):
+    s.allUsages = obj.allUsages
+
+proc transitionGenericParamToType*(s: PSym) =
+  transitionSymKindCommon(skType)
+  s.typeInstCache = obj.typeInstCache
+
+proc transitionRoutineSymKind*(s: PSym, kind: range[skProc..skTemplate]) =
+  transitionSymKindCommon(kind)
+  s.procInstCache = obj.procInstCache
+  s.gcUnsafetyReason = obj.gcUnsafetyReason
+  s.transformedBody = obj.transformedBody
+
+proc transitionToLet*(s: PSym) =
+  transitionSymKindCommon(skLet)
+  s.guard = obj.guard
+  s.bitsize = obj.bitsize
+  s.alignment = obj.alignment
+
 proc shallowCopy*(src: PNode): PNode =
   # does not copy its sons, but provides space for them:
   if src == nil: return nil

compiler/canonicalizer.nim

@@ -282,7 +282,7 @@ proc encodeType(w: PRodWriter, t: PType, result: var string) =
   result.add('+')
   encodeVInt(t.id, result)
   if t.n != nil:
-    encodeNode(w, unknownLineInfo(), t.n, result)
+    encodeNode(w, unknownLineInfo, t.n, result)
   if t.flags != {}:
     result.add('$')
     encodeVInt(cast[int32](t.flags), result)
@@ -364,7 +364,7 @@ proc encodeSym(w: PRodWriter, s: PSym, result: var string) =
   if s.annex != nil: encodeLib(w, s.annex, s.info, result)
   if s.constraint != nil:
     result.add('#')
-    encodeNode(w, unknownLineInfo(), s.constraint, result)
+    encodeNode(w, unknownLineInfo, s.constraint, result)
   # lazy loading will soon reload the ast lazily, so the ast needs to be
   # the last entry of a symbol:
   if s.ast != nil:

compiler/ccgexprs.nim

@@ -1457,7 +1457,7 @@ proc genArrToSeq(p: BProc, n: PNode, d: var TLoc) =
       genAssignment(p, elem, arr, {needToCopy})
   else:
     var i: TLoc
-    getTemp(p, getSysType(p.module.g.graph, unknownLineInfo(), tyInt), i)
+    getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt), i)
     linefmt(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",  [i.r, L])
     initLoc(elem, locExpr, lodeTyp elemType(skipTypes(n.typ, abstractInst)), OnHeap)
     elem.r = ropecg(p.module, "$1$3[$2]", [rdLoc(d), rdLoc(i), dataField(p)])
@@ -1847,10 +1847,10 @@ proc genSetOp(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
       initLocExpr(p, e[1], a)
       putIntoDest(p, d, e, ropecg(p.module, "#cardSet($1, $2)", [rdCharLoc(a), size]))
     of mLtSet, mLeSet:
-      getTemp(p, getSysType(p.module.g.graph, unknownLineInfo(), tyInt), i) # our counter
+      getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt), i) # our counter
       initLocExpr(p, e[1], a)
       initLocExpr(p, e[2], b)
-      if d.k == locNone: getTemp(p, getSysType(p.module.g.graph, unknownLineInfo(), tyBool), d)
+      if d.k == locNone: getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyBool), d)
       if op == mLtSet:
         linefmt(p, cpsStmts, lookupOpr[mLtSet],
            [rdLoc(i), size, rdLoc(d), rdLoc(a), rdLoc(b)])
@@ -1866,7 +1866,7 @@ proc genSetOp(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
       putIntoDest(p, d, e, ropecg(p.module, "(#nimCmpMem($1, $2, $3)==0)", [a.rdCharLoc, b.rdCharLoc, size]))
     of mMulSet, mPlusSet, mMinusSet, mSymDiffSet:
       # we inline the simple for loop for better code generation:
-      getTemp(p, getSysType(p.module.g.graph, unknownLineInfo(), tyInt), i) # our counter
+      getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt), i) # our counter
       initLocExpr(p, e[1], a)
       initLocExpr(p, e[2], b)
       if d.k == locNone: getTemp(p, setType, d)
@@ -2319,7 +2319,7 @@ proc genSetConstr(p: BProc, e: PNode, d: var TLoc) =
           [rdLoc(d), getTypeDesc(p.module, e.typ)])
       for it in e.sons:
         if it.kind == nkRange:
-          getTemp(p, getSysType(p.module.g.graph, unknownLineInfo(), tyInt), idx) # our counter
+          getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt), idx) # our counter
           initLocExpr(p, it[0], a)
           initLocExpr(p, it[1], b)
           lineF(p, cpsStmts, "for ($1 = $3; $1 <= $4; $1++) $n" &
@@ -2335,7 +2335,7 @@ proc genSetConstr(p: BProc, e: PNode, d: var TLoc) =
       lineF(p, cpsStmts, "$1 = 0;$n", [rdLoc(d)])
       for it in e.sons:
         if it.kind == nkRange:
-          getTemp(p, getSysType(p.module.g.graph, unknownLineInfo(), tyInt), idx) # our counter
+          getTemp(p, getSysType(p.module.g.graph, unknownLineInfo, tyInt), idx) # our counter
           initLocExpr(p, it[0], a)
           initLocExpr(p, it[1], b)
           lineF(p, cpsStmts, "for ($1 = $3; $1 <= $4; $1++) $n" &

compiler/ccgstmts.nim

@@ -558,7 +558,7 @@ proc genComputedGoto(p: BProc; n: PNode) =
       let it = n[j]
       if it.kind in {nkLetSection, nkVarSection}:
         let asgn = copyNode(it)
-        asgn.kind = nkAsgn
+        asgn.transitionSonsKind(nkAsgn)
         asgn.sons.setLen 2
         for sym, value in it.fieldValuePairs:
           if value.kind != nkEmpty:

compiler/ccgtrav.nim

@@ -75,7 +75,7 @@ proc genTraverseProc(c: TTraversalClosure, accessor: Rope, typ: PType) =
   of tyArray:
     let arraySize = lengthOrd(c.p.config, typ[0])
     var i: TLoc
-    getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo(), tyInt), i)
+    getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt), i)
     let oldCode = p.s(cpsStmts)
     linefmt(p, cpsStmts, "for ($1 = 0; $1 < $2; $1++) {$n",
             [i.r, arraySize])
@@ -119,7 +119,7 @@ proc genTraverseProcSeq(c: TTraversalClosure, accessor: Rope, typ: PType) =
   var p = c.p
   assert typ.kind == tySequence
   var i: TLoc
-  getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo(), tyInt), i)
+  getTemp(p, getSysType(c.p.module.g.graph, unknownLineInfo, tyInt), i)
   let oldCode = p.s(cpsStmts)
   var a: TLoc
   a.r = accessor

compiler/ccgtypes.nim

@@ -696,7 +696,7 @@ proc getTypeDescAux(m: BModule, origTyp: PType, check: var IntSet): Rope =
     var etB = et.skipTypes(abstractInst)
     if mapType(m.config, t) == ctPtrToArray:
       if etB.kind == tySet:
-        et = getSysType(m.g.graph, unknownLineInfo(), tyUInt8)
+        et = getSysType(m.g.graph, unknownLineInfo, tyUInt8)
       else:
         et = elemType(etB)
       etB = et.skipTypes(abstractInst)

compiler/cgen.nim

@@ -480,7 +480,7 @@ proc getIntTemp(p: BProc, result: var TLoc) =
   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.lode = lodeTyp getSysType(p.module.g.graph, unknownLineInfo, tyInt)
   result.flags = {}
 
 proc localVarDecl(p: BProc; n: PNode): Rope =

compiler/cgmeth.nim

@@ -230,9 +230,9 @@ proc genDispatcher(g: ModuleGraph; methods: seq[PSym], relevantCols: IntSet): PS
   var paramLen = base.typ.len
   var nilchecks = newNodeI(nkStmtList, base.info)
   var disp = newNodeI(nkIfStmt, base.info)
-  var ands = getSysMagic(g, unknownLineInfo(), "and", mAnd)
-  var iss = getSysMagic(g, unknownLineInfo(), "of", mOf)
-  let boolType = getSysType(g, unknownLineInfo(), tyBool)
+  var ands = getSysMagic(g, unknownLineInfo, "and", mAnd)
+  var iss = getSysMagic(g, unknownLineInfo, "of", mOf)
+  let boolType = getSysType(g, unknownLineInfo, tyBool)
   for col in 1..<paramLen:
     if contains(relevantCols, col):
       let param = base.typ.n[col].sym

compiler/closureiters.nim

@@ -778,7 +778,7 @@ proc lowerStmtListExprs(ctx: var Ctx, n: PNode, needsSplit: var bool): PNode =
       result = newNodeI(nkStmtListExpr, n.info)
       result.typ = n.typ
       let (st, ex) = exprToStmtList(n[1])
-      n.kind = nkBlockStmt
+      n.transitionSonsKind(nkBlockStmt)
       n.typ = nil
       n[1] = st
       result.add(n)

compiler/lambdalifting.nim

@@ -837,12 +837,12 @@ proc liftIterToProc*(g: ModuleGraph; fn: PSym; body: PNode; ptrType: PType): PNo
   # pretend 'fn' is a closure iterator for the analysis:
   let oldKind = fn.kind
   let oldCC = fn.typ.callConv
-  fn.kind = skIterator
+  fn.transitionRoutineSymKind(skIterator)
   fn.typ.callConv = ccClosure
   d.ownerToType[fn.id] = ptrType
   detectCapturedVars(body, fn, d)
   result = liftCapturedVars(body, fn, d, c)
-  fn.kind = oldKind
+  fn.transitionRoutineSymKind(oldKind)
   fn.typ.callConv = oldCC
 
 proc liftLambdas*(g: ModuleGraph; fn: PSym, body: PNode; tooEarly: var bool): PNode =
@@ -959,7 +959,7 @@ proc liftForLoop*(g: ModuleGraph; body: PNode; owner: PSym): PNode =
   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.kind = skLet
+      body[i].sym.transitionToLet()
     vpart.add body[i]
 
   vpart.add newNodeI(nkEmpty, body.info) # no explicit type

compiler/lineinfos.nim

@@ -236,11 +236,7 @@ proc raiseRecoverableError*(msg: string) {.noinline.} =
 
 const
   InvalidFileIdx* = FileIndex(-1)
-
-proc unknownLineInfo*(): TLineInfo =
-  result.line = uint16(0)
-  result.col = int16(-1)
-  result.fileIndex = InvalidFileIdx
+  unknownLineInfo* = TLineInfo(line: 0, col: -1, fileIndex: InvalidFileIdx)
 
 type
   Severity* {.pure.} = enum ## VS Code only supports these three
@@ -267,7 +263,7 @@ type
 
 proc initMsgConfig*(): MsgConfig =
   result.msgContext = @[]
-  result.lastError = unknownLineInfo()
+  result.lastError = unknownLineInfo
   result.filenameToIndexTbl = initTable[string, FileIndex]()
   result.fileInfos = @[]
   result.errorOutputs = {eStdOut, eStdErr}

compiler/lowerings.nim

@@ -323,7 +323,7 @@ proc genDeref*(n: PNode; k = nkHiddenDeref): PNode =
   result.add n
 
 proc callCodegenProc*(g: ModuleGraph; name: string;
-                      info: TLineInfo = unknownLineInfo();
+                      info: TLineInfo = unknownLineInfo;
                       arg1, arg2, arg3, optionalArgs: PNode = nil): PNode =
   result = newNodeI(nkCall, info)
   let sym = magicsys.getCompilerProc(g, name)

compiler/modulegraphs.nim

@@ -163,7 +163,7 @@ proc stopCompile*(g: ModuleGraph): bool {.inline.} =
   result = g.doStopCompile != nil and g.doStopCompile()
 
 proc createMagic*(g: ModuleGraph; name: string, m: TMagic): PSym =
-  result = newSym(skProc, getIdent(g.cache, name), nil, unknownLineInfo(), {})
+  result = newSym(skProc, getIdent(g.cache, name), nil, unknownLineInfo, {})
   result.magic = m
 
 proc newModuleGraph*(cache: IdentCache; config: ConfigRef): ModuleGraph =

compiler/modules.nim

@@ -55,16 +55,14 @@ proc partialInitModule(result: PSym; graph: ModuleGraph; fileIdx: FileIndex; fil
   strTableAdd(packSym.tab, result)
 
 proc newModule(graph: ModuleGraph; fileIdx: FileIndex): PSym =
+  let filename = AbsoluteFile toFullPath(graph.config, fileIdx)
   # We cannot call ``newSym`` here, because we have to circumvent the ID
   # mechanism, which we do in order to assign each module a persistent ID.
-  new(result)
-  result.id = -1             # for better error checking
-  result.kind = skModule
-  let filename = AbsoluteFile toFullPath(graph.config, fileIdx)
-  result.name = getIdent(graph.cache, splitFile(filename).name)
+  result = PSym(kind: skModule, id: -1, # for better error checking
+                name: getIdent(graph.cache, splitFile(filename).name),
+                info: newLineInfo(fileIdx, 1, 1))
   if not isNimIdentifier(result.name.s):
     rawMessage(graph.config, errGenerated, "invalid module name: " & result.name.s)
-  result.info = newLineInfo(fileIdx, 1, 1)
   partialInitModule(result, graph, fileIdx, filename)
 
 proc compileModule*(graph: ModuleGraph; fileIdx: FileIndex; flags: TSymFlags): PSym =