#
#
# The Nim Compiler
# (c) Copyright 2013 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
# this module does the semantic checking for expressions
# included from sem.nim
proc semTemplateExpr(c: PContext, n: PNode, s: PSym,
flags: TExprFlags = {}): PNode =
markUsed(n.info, s)
styleCheckUse(n.info, s)
pushInfoContext(n.info)
result = evalTemplate(n, s, getCurrOwner(), efFromHlo in flags)
if efNoSemCheck notin flags: result = semAfterMacroCall(c, result, s, flags)
popInfoContext()
proc semFieldAccess(c: PContext, n: PNode, flags: TExprFlags = {}): PNode
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.kind == nkEmpty and result.typ.isNil:
# do not produce another redundant error message:
#raiseRecoverableError("")
# result = errorNode(c, n)
if result.typ != nil:
# XXX tyGenericInst here?
if result.typ.kind == tyVar: result = newDeref(result)
elif {efWantStmt, efAllowStmt} * flags != {}:
result.typ = newTypeS(tyVoid, c)
else:
localError(n.info, errExprXHasNoType,
renderTree(result, {renderNoComments}))
result.typ = errorType(c)
proc semExprWithType(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
result = semExpr(c, n, flags+{efWantValue})
if result.isNil or result.kind == nkEmpty:
# do not produce another redundant error message:
#raiseRecoverableError("")
result = errorNode(c, n)
if result.typ == nil or result.typ == enforceVoidContext:
# we cannot check for 'void' in macros ...
localError(n.info, errExprXHasNoType,
renderTree(result, {renderNoComments}))
result.typ = errorType(c)
else:
if efNoProcvarCheck notin flags: semProcvarCheck(c, result)
if result.typ.kind == tyVar: result = newDeref(result)
semDestructorCheck(c, result, flags)
proc semExprNoDeref(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
result = semExpr(c, n, flags)
if result.kind == nkEmpty:
# do not produce another redundant error message:
result = errorNode(c, n)
if result.typ == nil:
localError(n.info, errExprXHasNoType,
renderTree(result, {renderNoComments}))
result.typ = errorType(c)
else:
semProcvarCheck(c, result)
semDestructorCheck(c, result, flags)
proc semSymGenericInstantiation(c: PContext, n: PNode, s: PSym): PNode =
result = symChoice(c, n, s, scClosed)
proc inlineConst(n: PNode, s: PSym): PNode {.inline.} =
result = copyTree(s.ast)
if result.isNil:
localError(n.info, "constant of type '" & typeToString(s.typ) & "' has no value")
result = newSymNode(s)
else:
result.typ = s.typ
result.info = n.info
type
TConvStatus = enum
convOK,
convNotNeedeed,
convNotLegal
proc checkConversionBetweenObjects(castDest, src: PType; pointers: int): TConvStatus =
let diff = inheritanceDiff(castDest, src)
return if diff == high(int) or (pointers > 1 and diff != 0):
convNotLegal
else:
convOK
const
IntegralTypes = {tyBool, tyEnum, tyChar, tyInt..tyUInt64}
proc checkConvertible(c: PContext, castDest, src: PType): TConvStatus =
result = convOK
if sameType(castDest, src) and castDest.sym == src.sym:
# don't annoy conversions that may be needed on another processor:
if castDest.kind notin IntegralTypes+{tyRange}:
result = convNotNeedeed
return
var d = skipTypes(castDest, abstractVar)
var s = skipTypes(src, abstractVar-{tyTypeDesc})
var pointers = 0
while (d != nil) and (d.kind in {tyPtr, tyRef}) and (d.kind == s.kind):
d = d.lastSon
s = s.lastSon
inc pointers
if d == nil:
result = convNotLegal
elif d.kind == tyObject and s.kind == tyObject:
result = checkConversionBetweenObjects(d, s, pointers)
elif (skipTypes(castDest, abstractVarRange).kind in IntegralTypes) and
(skipTypes(src, abstractVarRange-{tyTypeDesc}).kind in IntegralTypes):
# accept conversion between integral types
discard
else:
# we use d, s here to speed up that operation a bit:
case cmpTypes(c, d, s)
of isNone, isGeneric:
if not compareTypes(castDest, src, dcEqIgnoreDistinct):
result = convNotLegal
else:
discard
proc isCastable(dst, src: PType): bool =
## Checks whether the source type can be casted to the destination type.
## Casting is very unrestrictive; casts are allowed as long as
## castDest.size >= src.size, and typeAllowed(dst, skParam)
#const
# castableTypeKinds = {tyInt, tyPtr, tyRef, tyCstring, tyString,
# tySequence, tyPointer, tyNil, tyOpenArray,
# tyProc, tySet, tyEnum, tyBool, tyChar}
if skipTypes(dst, abstractInst-{tyOpenArray}).kind == tyOpenArray:
return false
var dstSize, srcSize: BiggestInt
dstSize = computeSize(dst)
srcSize = computeSize(src)
if dstSize < 0:
result = false
elif srcSize < 0:
result = false
elif typeAllowed(dst, skParam) != nil:
result = false
else:
result = (dstSize >= srcSize) or
(skipTypes(dst, abstractInst).kind in IntegralTypes) or
(skipTypes(src, abstractInst-{tyTypeDesc}).kind in IntegralTypes)
if result and src.kind == tyNil:
result = dst.size <= platform.ptrSize
proc isSymChoice(n: PNode): bool {.inline.} =
result = n.kind in nkSymChoices
proc maybeLiftType(t: var PType, c: PContext, info: TLineInfo) =
# XXX: liftParamType started to perform addDecl
# we could do that instead in semTypeNode by snooping for added
# gnrc. params, then it won't be necessary to open a new scope here
openScope(c)
var lifted = liftParamType(c, skType, newNodeI(nkArgList, info),
t, ":anon", info)
closeScope(c)
if lifted != nil: t = lifted
proc semConv(c: PContext, n: PNode): PNode =
if sonsLen(n) != 2:
localError(n.info, errConvNeedsOneArg)
return n
result = newNodeI(nkConv, n.info)
var targetType = semTypeNode(c, n.sons[0], nil).skipTypes({tyTypeDesc})
maybeLiftType(targetType, c, n[0].info)
result.addSon copyTree(n.sons[0])
var op = semExprWithType(c, n.sons[1])
if targetType.isMetaType:
let final = inferWithMetatype(c, targetType, op, true)
result.addSon final
result.typ = final.typ
return
result.typ = targetType
addSon(result, op)
if not isSymChoice(op):
let status = checkConvertible(c, result.typ, op.typ)
case status
of convOK:
# handle SomeProcType(SomeGenericProc)
if op.kind == nkSym and op.sym.isGenericRoutine:
result.sons[1] = fitNode(c, result.typ, result.sons[1])
elif op.kind == nkPar and targetType.kind == tyTuple:
op = fitNode(c, targetType, op)
of convNotNeedeed:
message(n.info, hintConvFromXtoItselfNotNeeded, result.typ.typeToString)
of convNotLegal:
result = fitNode(c, result.typ, result.sons[1])
if result == nil:
localError(n.info, errGenerated, msgKindToString(errIllegalConvFromXtoY)%
[op.typ.typeToString, result.typ.typeToString])
else:
for i in countup(0, sonsLen(op) - 1):
let it = op.sons[i]
let status = checkConvertible(c, result.typ, it.typ)
if status in {convOK, convNotNeedeed}:
markUsed(n.info, it.sym)
styleCheckUse(n.info, it.sym)
markIndirect(c, it.sym)
return it
errorUseQualifier(c, n.info, op.sons[0].sym)
proc semCast(c: PContext, n: PNode): PNode =
## Semantically analyze a casting ("cast[type](param)")
checkSonsLen(n, 2)
result = newNodeI(nkCast, n.info)
result.typ = semTypeNode(c, n.sons[0], nil)
addSon(result, copyTree(n.sons[0]))
addSon(result, semExprWithType(c, n.sons[1]))
if not isCastable(result.typ, result.sons[1].typ):
localError(result.info, errExprCannotBeCastedToX,
typeToString(result.typ))
proc semLowHigh(c: PContext, n: PNode, m: TMagic): PNode =
const
opToStr: array[mLow..mHigh, string] = ["low", "high"]
if sonsLen(n) != 2:
localError(n.info, errXExpectsTypeOrValue, opToStr[m])
else:
n.sons[1] = semExprWithType(c, n.sons[1], {efDetermineType})
var typ = skipTypes(n.sons[1].typ, abstractVarRange +
{tyTypeDesc, tyFieldAccessor})
case typ.kind
of tySequence, tyString, tyCString, tyOpenArray, tyVarargs:
n.typ = getSysType(tyInt)
of tyArrayConstr, tyArray:
n.typ = typ.sons[0] # indextype
of tyInt..tyInt64, tyChar, tyBool, tyEnum, tyUInt8, tyUInt16, tyUInt32:
# do not skip the range!
n.typ = n.sons[1].typ.skipTypes(abstractVar + {tyFieldAccessor})
of tyGenericParam:
# prepare this for resolving in semtypinst:
# we must use copyTree here in order to avoid creating a cycle
# that could easily turn into an infinite recursion in semtypinst
n.typ = makeTypeFromExpr(c, n.copyTree)
else:
localError(n.info, errInvalidArgForX, opToStr[m])
result = n
proc semSizeof(c: PContext, n: PNode): PNode =
if sonsLen(n) != 2:
localError(n.info, errXExpectsTypeOrValue, "sizeof")
else:
n.sons[1] = semExprWithType(c, n.sons[1], {efDetermineType})
#restoreOldStyleType(n.sons[1])
n.typ = getSysType(tyInt)
result = n
proc semOf(c: PContext, n: PNode): PNode =
if sonsLen(n) == 3:
n.sons[1] = semExprWithType(c, n.sons[1])
n.sons[2] = semExprWithType(c, n.sons[2], {efDetermineType})
#restoreOldStyleType(n.sons[1])
#restoreOldStyleType(n.sons[2])
let a = skipTypes(n.sons[1].typ, abstractPtrs)
let b = skipTypes(n.sons[2].typ, abstractPtrs)
let x = skipTypes(n.sons[1].typ, abstractPtrs-{tyTypeDesc})
let y = skipTypes(n.sons[2].typ, abstractPtrs-{tyTypeDesc})
if x.kind == tyTypeDesc or y.kind != tyTypeDesc:
localError(n.info, errXExpectsObjectTypes, "of")
elif b.kind != tyObject or a.kind != tyObject:
localError(n.info, errXExpectsObjectTypes, "of")
else:
let diff = inheritanceDiff(a, b)
# | returns: 0 iff `a` == `b`
# | returns: -x iff `a` is the x'th direct superclass of `b`
# | returns: +x iff `a` is the x'th direct subclass of `b`
# | returns: `maxint` iff `a` and `b` are not compatible at all
if diff <= 0:
# optimize to true:
message(n.info, hintConditionAlwaysTrue, renderTree(n))
result = newIntNode(nkIntLit, 1)
result.info = n.info
result.typ = getSysType(tyBool)
return result
elif diff == high(int):
localError(n.info, errXcanNeverBeOfThisSubtype, typeToString(a))
else:
localError(n.info, errXExpectsTwoArguments, "of")
n.typ = getSysType(tyBool)
result = n
proc isOpImpl(c: PContext, n: PNode): PNode =
internalAssert n.sonsLen == 3 and
n[1].typ != nil and n[1].typ.kind == tyTypeDesc and
n[2].kind in {nkStrLit..nkTripleStrLit, nkType}
let t1 = n[1].typ.skipTypes({tyTypeDesc, tyFieldAccessor})
if n[2].kind in {nkStrLit..nkTripleStrLit}:
case n[2].strVal.normalize
of "closure":
let t = skipTypes(t1, abstractRange)
result = newIntNode(nkIntLit, ord(t.kind == tyProc and
t.callConv == ccClosure and
tfIterator notin t.flags))
else:
result = newIntNode(nkIntLit, 0)
else:
var t2 = n[2].typ.skipTypes({tyTypeDesc})
maybeLiftType(t2, c, n.info)
var m: TCandidate
initCandidate(c, m, t2)
let match = typeRel(m, t2, t1) >= isSubtype # isNone
result = newIntNode(nkIntLit, ord(match))
result.typ = n.typ
proc semIs(c: PContext, n: PNode): PNode =
if sonsLen(n) != 3:
localError(n.info, errXExpectsTwoArguments, "is")
result = n
n.typ = getSysType(tyBool)
n.sons[1] = semExprWithType(c, n[1], {efDetermineType, efWantIterator})
if n[2].kind notin {nkStrLit..nkTripleStrLit}:
let t2 = semTypeNode(c, n[2], nil)
n.sons[2] = newNodeIT(nkType, n[2].info, t2)
let lhsType = n[1].typ
if lhsType.kind != tyTypeDesc:
n.sons[1] = makeTypeSymNode(c, lhsType, n[1].info)
elif lhsType.base.kind == tyNone:
# this is a typedesc variable, leave for evals
return
# BUGFIX: don't evaluate this too early: ``T is void``
if not n[1].typ.base.containsGenericType: result = isOpImpl(c, n)
proc semOpAux(c: PContext, n: PNode) =
const flags = {efDetermineType}
for i in countup(1, n.sonsLen-1):
var a = n.sons[i]
if a.kind == nkExprEqExpr and sonsLen(a) == 2:
var info = a.sons[0].info
a.sons[0] = newIdentNode(considerQuotedIdent(a.sons[0]), info)
a.sons[1] = semExprWithType(c, a.sons[1], flags)
a.typ = a.sons[1].typ
else:
n.sons[i] = semExprWithType(c, a, flags)
proc overloadedCallOpr(c: PContext, n: PNode): PNode =
# quick check if there is *any* () operator overloaded:
var par = getIdent("()")
if searchInScopes(c, par) == nil:
result = nil
else:
result = newNodeI(nkCall, n.info)
addSon(result, newIdentNode(par, n.info))
for i in countup(0, sonsLen(n) - 1): addSon(result, n.sons[i])
result = semExpr(c, result)
proc changeType(n: PNode, newType: PType, check: bool) =
case n.kind
of nkCurly, nkBracket:
for i in countup(0, sonsLen(n) - 1):
changeType(n.sons[i], elemType(newType), check)
of nkPar:
let tup = newType.skipTypes({tyGenericInst})
if tup.kind != tyTuple:
if tup.kind == tyObject: return
globalError(n.info, "no tuple type for constructor")
elif sonsLen(n) > 0 and n.sons[0].kind == nkExprColonExpr:
# named tuple?
for i in countup(0, sonsLen(n) - 1):
var m = n.sons[i].sons[0]
if m.kind != nkSym:
globalError(m.info, "invalid tuple constructor")
return
if tup.n != nil:
var f = getSymFromList(tup.n, m.sym.name)
if f == nil:
globalError(m.info, "unknown identifier: " & m.sym.name.s)
return
changeType(n.sons[i].sons[1], f.typ, check)
else:
changeType(n.sons[i].sons[1], tup.sons[i], check)
else:
for i in countup(0, sonsLen(n) - 1):
changeType(n.sons[i], tup.sons[i], check)
when false:
var m = n.sons[i]
var a = newNodeIT(nkExprColonExpr, m.info, newType.sons[i])
addSon(a, newSymNode(newType.n.sons[i].sym))
addSon(a, m)
changeType(m, tup.sons[i], check)
of nkCharLit..nkUInt64Lit:
if check and n.kind != nkUInt64Lit:
let value = n.intVal
if value < firstOrd(newType) or value > lastOrd(newType):
localError(n.info, errGenerated, "cannot convert " & $value &
" to " & typeToString(newType))
else: discard
n.typ = newType
proc arrayConstrType(c: PContext, n: PNode): PType =
var typ = newTypeS(tyArrayConstr, c)
rawAddSon(typ, nil) # index type
if sonsLen(n) == 0:
rawAddSon(typ, newTypeS(tyEmpty, c)) # needs an empty basetype!
else:
var t = skipTypes(n.sons[0].typ, {tyGenericInst, tyVar, tyOrdinal})
addSonSkipIntLit(typ, t)
typ.sons[0] = makeRangeType(c, 0, sonsLen(n) - 1, n.info)
result = typ
proc semArrayConstr(c: PContext, n: PNode, flags: TExprFlags): PNode =
result = newNodeI(nkBracket, n.info)
result.typ = newTypeS(tyArrayConstr, c)
rawAddSon(result.typ, nil) # index type
if sonsLen(n) == 0:
rawAddSon(result.typ, newTypeS(tyEmpty, c)) # needs an empty basetype!
else:
var x = n.sons[0]
var lastIndex: BiggestInt = 0
var indexType = getSysType(tyInt)
if x.kind == nkExprColonExpr and sonsLen(x) == 2:
var idx = semConstExpr(c, x.sons[0])
lastIndex = getOrdValue(idx)
indexType = idx.typ
x = x.sons[1]
let yy = semExprWithType(c, x)
var typ = yy.typ
addSon(result, yy)
#var typ = skipTypes(result.sons[0].typ, {tyGenericInst, tyVar, tyOrdinal})
for i in countup(1, sonsLen(n) - 1):
x = n.sons[i]
if x.kind == nkExprColonExpr and sonsLen(x) == 2:
var idx = semConstExpr(c, x.sons[0])
idx = fitNode(c, indexType, idx)
if lastIndex+1 != getOrdValue(idx):
localError(x.info, errInvalidOrderInArrayConstructor)
x = x.sons[1]
let xx = semExprWithType(c, x, flags*{efAllowDestructor})
result.add xx
typ = commonType(typ, xx.typ)
#n.sons[i] = semExprWithType(c, x, flags*{efAllowDestructor})
#addSon(result, fitNode(c, typ, n.sons[i]))
inc(lastIndex)
addSonSkipIntLit(result.typ, typ)
for i in 0 .. <result.len:
result.sons[i] = fitNode(c, typ, result.sons[i])
result.typ.sons[0] = makeRangeType(c, 0, sonsLen(result) - 1, n.info)
proc fixAbstractType(c: PContext, n: PNode) =
for i in 1 .. < n.len:
let it = n.sons[i]
# do not get rid of nkHiddenSubConv for OpenArrays, the codegen needs it:
if it.kind == nkHiddenSubConv and
skipTypes(it.typ, abstractVar).kind notin {tyOpenArray, tyVarargs}:
if skipTypes(it.sons[1].typ, abstractVar).kind in
{tyNil, tyArrayConstr, tyTuple, tySet}:
var s = skipTypes(it.typ, abstractVar)
if s.kind != tyExpr:
changeType(it.sons[1], s, check=true)
n.sons[i] = it.sons[1]
when false:
# XXX finally rewrite that crap!
for i in countup(1, sonsLen(n) - 1):
var it = n.sons[i]
case it.kind
of nkHiddenStdConv, nkHiddenSubConv:
if it.sons[1].kind == nkBracket:
it.sons[1].typ = arrayConstrType(c, it.sons[1])
#it.sons[1] = semArrayConstr(c, it.sons[1])
if skipTypes(it.typ, abstractVar).kind in {tyOpenArray, tyVarargs}:
#if n.sons[0].kind == nkSym and IdentEq(n.sons[0].sym.name, "[]="):
# debug(n)
var s = skipTypes(it.sons[1].typ, abstractVar)
if s.kind == tyArrayConstr and s.sons[1].kind == tyEmpty:
s = copyType(s, getCurrOwner(), false)
skipTypes(s, abstractVar).sons[1] = elemType(
skipTypes(it.typ, abstractVar))
it.sons[1].typ = s
elif s.kind == tySequence and s.sons[0].kind == tyEmpty:
s = copyType(s, getCurrOwner(), false)
skipTypes(s, abstractVar).sons[0] = elemType(
skipTypes(it.typ, abstractVar))
it.sons[1].typ = s
elif skipTypes(it.sons[1].typ, abstractVar).kind in
{tyNil, tyArrayConstr, tyTuple, tySet}:
var s = skipTypes(it.typ, abstractVar)
if s.kind != tyExpr:
changeType(it.sons[1], s, check=true)
n.sons[i] = it.sons[1]
of nkBracket:
# an implicitly constructed array (passed to an open array):
n.sons[i] = semArrayConstr(c, it, {})
else:
discard
#if (it.typ == nil):
# InternalError(it.info, "fixAbstractType: " & renderTree(it))
proc isAssignable(c: PContext, n: PNode; isUnsafeAddr=false): TAssignableResult =
result = parampatterns.isAssignable(c.p.owner, n, isUnsafeAddr)
proc newHiddenAddrTaken(c: PContext, n: PNode): PNode =
if n.kind == nkHiddenDeref and not (gCmd == cmdCompileToCpp or
sfCompileToCpp in c.module.flags):
checkSonsLen(n, 1)
result = n.sons[0]
else:
result = newNodeIT(nkHiddenAddr, n.info, makeVarType(c, n.typ))
addSon(result, n)
if isAssignable(c, n) notin {arLValue, arLocalLValue}:
localError(n.info, errVarForOutParamNeeded)
proc analyseIfAddressTaken(c: PContext, n: PNode): PNode =
result = n
case n.kind
of nkSym:
# n.sym.typ can be nil in 'check' mode ...
if n.sym.typ != nil and
skipTypes(n.sym.typ, abstractInst-{tyTypeDesc}).kind != tyVar:
incl(n.sym.flags, sfAddrTaken)
result = newHiddenAddrTaken(c, n)
of nkDotExpr:
checkSonsLen(n, 2)
if n.sons[1].kind != nkSym:
internalError(n.info, "analyseIfAddressTaken")
return
if skipTypes(n.sons[1].sym.typ, abstractInst-{tyTypeDesc}).kind != tyVar:
incl(n.sons[1].sym.flags, sfAddrTaken)
result = newHiddenAddrTaken(c, n)
of nkBracketExpr:
checkMinSonsLen(n, 1)
if skipTypes(n.sons[0].typ, abstractInst-{tyTypeDesc}).kind != tyVar:
if n.sons[0].kind == nkSym: incl(n.sons[0].sym.flags, sfAddrTaken)
result = newHiddenAddrTaken(c, n)
else:
result = newHiddenAddrTaken(c, n)
proc analyseIfAddressTakenInCall(c: PContext, n: PNode) =
checkMinSonsLen(n, 1)
const
FakeVarParams = {mNew, mNewFinalize, mInc, ast.mDec, mIncl, mExcl,
mSetLengthStr, mSetLengthSeq, mAppendStrCh, mAppendStrStr, mSwap,
mAppendSeqElem, mNewSeq, mReset, mShallowCopy, mDeepCopy}
# get the real type of the callee
# it may be a proc var with a generic alias type, so we skip over them
var t = n.sons[0].typ.skipTypes({tyGenericInst})
if n.sons[0].kind == nkSym and n.sons[0].sym.magic in FakeVarParams:
# BUGFIX: check for L-Value still needs to be done for the arguments!
# note sometimes this is eval'ed twice so we check for nkHiddenAddr here:
for i in countup(1, sonsLen(n) - 1):
if i < sonsLen(t) and t.sons[i] != nil and
skipTypes(t.sons[i], abstractInst-{tyTypeDesc}).kind == tyVar:
if isAssignable(c, n.sons[i]) notin {arLValue, arLocalLValue}:
if n.sons[i].kind != nkHiddenAddr:
localError(n.sons[i].info, errVarForOutParamNeeded)
return
for i in countup(1, sonsLen(n) - 1):
if n.sons[i].kind == nkHiddenCallConv:
# we need to recurse explicitly here as converters can create nested
# calls and then they wouldn't be analysed otherwise
analyseIfAddressTakenInCall(c, n.sons[i])
semProcvarCheck(c, n.sons[i])
if i < sonsLen(t) and
skipTypes(t.sons[i], abstractInst-{tyTypeDesc}).kind == tyVar:
if n.sons[i].kind != nkHiddenAddr:
n.sons[i] = analyseIfAddressTaken(c, n.sons[i])
include semmagic
proc evalAtCompileTime(c: PContext, n: PNode): PNode =
result = n
if n.kind notin nkCallKinds or n.sons[0].kind != nkSym: return
var callee = n.sons[0].sym
# workaround for bug #537 (overly aggressive inlining leading to
# wrong NimNode semantics):
if n.typ != nil and tfTriggersCompileTime in n.typ.flags: return
# constant folding that is necessary for correctness of semantic pass:
if callee.magic != mNone and callee.magic in ctfeWhitelist and n.typ != nil:
var call = newNodeIT(nkCall, n.info, n.typ)
call.add(n.sons[0])
var allConst = true
for i in 1 .. < n.len:
var a = getConstExpr(c.module, n.sons[i])
if a == nil:
allConst = false
a = n.sons[i]
if a.kind == nkHiddenStdConv: a = a.sons[1]
call.add(a)
if allConst:
result = semfold.getConstExpr(c.module, call)
if result.isNil: result = n
else: return result
result.typ = semfold.getIntervalType(callee.magic, call)
block maybeLabelAsStatic:
# XXX: temporary work-around needed for tlateboundstatic.
# This is certainly not correct, but it will get the job
# done until we have a more robust infrastructure for
# implicit statics.
if n.len > 1:
for i in 1 .. <n.len:
# see bug #2113, it's possible that n[i].typ for errornous code:
if n[i].typ.isNil or n[i].typ.kind != tyStatic or
tfUnresolved notin n[i].typ.flags:
break maybeLabelAsStatic
n.typ = newTypeWithSons(c, tyStatic, @[n.typ])
n.typ.flags.incl tfUnresolved
# optimization pass: not necessary for correctness of the semantic pass
if {sfNoSideEffect, sfCompileTime} * callee.flags != {} and
{sfForward, sfImportc} * callee.flags == {} and n.typ != nil:
if sfCompileTime notin callee.flags and
optImplicitStatic notin gOptions: return
if callee.magic notin ctfeWhitelist: return
if callee.kind notin {skProc, skConverter} or callee.isGenericRoutine:
return
if n.typ != nil and typeAllowed(n.typ, skConst) != nil: return
var call = newNodeIT(nkCall, n.info, n.typ)
call.add(n.sons[0])
for i in 1 .. < n.len:
let a = getConstExpr(c.module, n.sons[i])
if a == nil: return n
call.add(a)
#echo "NOW evaluating at compile time: ", call.renderTree
if sfCompileTime in callee.flags:
result = evalStaticExpr(c.module, call, c.p.owner)
if result.isNil:
localError(n.info, errCannotInterpretNodeX, renderTree(call))
else: result = fixupTypeAfterEval(c, result, n)
else:
result = evalConstExpr(c.module, call)
if result.isNil: result = n
else: result = fixupTypeAfterEval(c, result, n)
#if result != n:
# echo "SUCCESS evaluated at compile time: ", call.renderTree
proc semStaticExpr(c: PContext, n: PNode): PNode =
let a = semExpr(c, n.sons[0])
result = evalStaticExpr(c.module, a, c.p.owner)
if result.isNil:
localError(n.info, errCannotInterpretNodeX, renderTree(n))
result = emptyNode
else:
result = fixupTypeAfterEval(c, result, a)
proc semOverloadedCallAnalyseEffects(c: PContext, n: PNode, nOrig: PNode,
flags: TExprFlags): PNode =
if flags*{efInTypeof, efWantIterator} != {}:
# consider: 'for x in pReturningArray()' --> we don't want the restriction
# to 'skIterator' anymore; skIterator is preferred in sigmatch already
# for typeof support.
# for ``type(countup(1,3))``, see ``tests/ttoseq``.
result = semOverloadedCall(c, n, nOrig,
{skProc, skMethod, skConverter, skMacro, skTemplate, skIterator})
else:
result = semOverloadedCall(c, n, nOrig,
{skProc, skMethod, skConverter, skMacro, skTemplate})
if result != nil:
if result.sons[0].kind != nkSym:
internalError("semOverloadedCallAnalyseEffects")
return
let callee = result.sons[0].sym
case callee.kind
of skMacro, skTemplate: discard
else:
if callee.kind == skIterator and callee.id == c.p.owner.id:
localError(n.info, errRecursiveDependencyX, callee.name.s)
# error correction, prevents endless for loop elimination in transf.
# See bug #2051:
result.sons[0] = newSymNode(errorSym(c, n))
proc semObjConstr(c: PContext, n: PNode, flags: TExprFlags): PNode
proc resolveIndirectCall(c: PContext; n, nOrig: PNode;
t: PType): TCandidate =
initCandidate(c, result, t)
matches(c, n, nOrig, result)
if result.state != csMatch:
# try to deref the first argument:
if experimentalMode(c) and canDeref(n):
n.sons[1] = n.sons[1].tryDeref
initCandidate(c, result, t)
matches(c, n, nOrig, result)
proc bracketedMacro(n: PNode): PSym =
if n.len >= 1 and n[0].kind == nkSym:
result = n[0].sym
if result.kind notin {skMacro, skTemplate}:
result = nil
proc semBracketedMacro(c: PContext; outer, inner: PNode; s: PSym;
flags: TExprFlags): PNode =
# We received untransformed bracket expression coming from macroOrTmpl[].
# Transform it to macro or template call, where first come normal
# arguments, next come generic template arguments.
var sons = newSeq[PNode]()
sons.add inner.sons[0]
# Normal arguments:
for i in 1..<outer.len:
sons.add outer.sons[i]
# Generic template arguments from bracket expression:
for i in 1..<inner.len:
sons.add inner.sons[i]
shallowCopy(outer.sons, sons)
# FIXME: Shouldn't we check sfImmediate and call semDirectOp?
# However passing to semDirectOp doesn't work here.
case s.kind
of skMacro: result = semMacroExpr(c, outer, outer, s, flags)
of skTemplate: result = semTemplateExpr(c, outer, s, flags)
else: assert(false)
return
proc semIndirectOp(c: PContext, n: PNode, flags: TExprFlags): PNode =
result = nil
checkMinSonsLen(n, 1)
var prc = n.sons[0]
if n.sons[0].kind == nkDotExpr:
checkSonsLen(n.sons[0], 2)
let n0 = semFieldAccess(c, n.sons[0])
if n0.kind == nkDotCall:
# it is a static call!
result = n0
result.kind = nkCall
result.flags.incl nfExplicitCall
for i in countup(1, sonsLen(n) - 1): addSon(result, n.sons[i])
return semExpr(c, result, flags)
else:
n.sons[0] = n0
else:
n.sons[0] = semExpr(c, n.sons[0], {efInCall})
let t = n.sons[0].typ
if t != nil and t.kind == tyVar:
n.sons[0] = newDeref(n.sons[0])
elif n.sons[0].kind == nkBracketExpr:
let s = bracketedMacro(n.sons[0])
if s != nil:
return semBracketedMacro(c, n, n.sons[0], s, flags)
let nOrig = n.copyTree
semOpAux(c, n)
var t: PType = nil
if n.sons[0].typ != nil:
t = skipTypes(n.sons[0].typ, abstractInst-{tyTypeDesc})
if t != nil and t.kind == tyProc:
# This is a proc variable, apply normal overload resolution
let m = resolveIndirectCall(c, n, nOrig, t)
if m.state != csMatch:
if c.compilesContextId > 0:
# speed up error generation:
globalError(n.info, errTypeMismatch, "")
return emptyNode
else:
var hasErrorType = false
var msg = msgKindToString(errTypeMismatch)
for i in countup(1, sonsLen(n) - 1):
if i > 1: add(msg, ", ")
let nt = n.sons[i].typ
add(msg, typeToString(nt))
if nt.kind == tyError:
hasErrorType = true
break
if not hasErrorType:
add(msg, ")\n" & msgKindToString(errButExpected) & "\n" &
typeToString(n.sons[0].typ))
localError(n.info, errGenerated, msg)
return errorNode(c, n)
result = nil
else:
result = m.call
instGenericConvertersSons(c, result, m)
elif t != nil and t.kind == tyTypeDesc:
if n.len == 1: return semObjConstr(c, n, flags)
return semConv(c, n)
else:
result = overloadedCallOpr(c, n)
# Now that nkSym does not imply an iteration over the proc/iterator space,
# the old ``prc`` (which is likely an nkIdent) has to be restored:
if result == nil:
# XXX: hmm, what kind of symbols will end up here?
# do we really need to try the overload resolution?
n.sons[0] = prc
nOrig.sons[0] = prc
n.flags.incl nfExprCall
result = semOverloadedCallAnalyseEffects(c, n, nOrig, flags)
if result == nil: return errorNode(c, n)
elif result.kind notin nkCallKinds:
# the semExpr() in overloadedCallOpr can even break this condition!
# See bug #904 of how to trigger it:
return result
#result = afterCallActions(c, result, nOrig, flags)
fixAbstractType(c, result)
analyseIfAddressTakenInCall(c, result)
if result.sons[0].kind == nkSym and result.sons[0].sym.magic != mNone:
result = magicsAfterOverloadResolution(c, result, flags)
result = evalAtCompileTime(c, result)
proc afterCallActions(c: PContext; n, orig: PNode, flags: TExprFlags): PNode =
result = n
let callee = result.sons[0].sym
case callee.kind
of skMacro: result = semMacroExpr(c, result, orig, callee, flags)
of skTemplate: result = semTemplateExpr(c, result, callee, flags)
else:
semFinishOperands(c, result)
activate(c, result)
fixAbstractType(c, result)
analyseIfAddressTakenInCall(c, result)
if callee.magic != mNone:
result = magicsAfterOverloadResolution(c, result, flags)
if c.inTypeClass == 0:
result = evalAtCompileTime(c, result)
proc semDirectOp(c: PContext, n: PNode, flags: TExprFlags): PNode =
# this seems to be a hotspot in the compiler!
let nOrig = n.copyTree
#semLazyOpAux(c, n)
result = semOverloadedCallAnalyseEffects(c, n, nOrig, flags)
if result != nil: result = afterCallActions(c, result, nOrig, flags)
else: result = errorNode(c, n)
proc buildEchoStmt(c: PContext, n: PNode): PNode =
# we MUST not check 'n' for semantics again here! But for now we give up:
result = newNodeI(nkCall, n.info)
var e = strTableGet(magicsys.systemModule.tab, getIdent"echo")
if e != nil:
add(result, newSymNode(e))
else:
localError(n.info, errSystemNeeds, "echo")
add(result, errorNode(c, n))
add(result, n)
result = semExpr(c, result)
proc semExprNoType(c: PContext, n: PNode): PNode =
result = semExpr(c, n, {efWantStmt})
discardCheck(c, result)
proc isTypeExpr(n: PNode): bool =
case n.kind
of nkType, nkTypeOfExpr: result = true
of nkSym: result = n.sym.kind == skType
else: result = false
proc createSetType(c: PContext; baseType: PType): PType =
assert baseType != nil
result = newTypeS(tySet, c)
rawAddSon(result, baseType)
proc lookupInRecordAndBuildCheck(c: PContext, n, r: PNode, field: PIdent,
check: var PNode): PSym =
# transform in a node that contains the runtime check for the
# field, if it is in a case-part...
result = nil
case r.kind
of nkRecList:
for i in countup(0, sonsLen(r) - 1):
result = lookupInRecordAndBuildCheck(c, n, r.sons[i], field, check)
if result != nil: return
of nkRecCase:
checkMinSonsLen(r, 2)
if (r.sons[0].kind != nkSym): illFormedAst(r)
result = lookupInRecordAndBuildCheck(c, n, r.sons[0], field, check)
if result != nil: return
let setType = createSetType(c, r.sons[0].typ)
var s = newNodeIT(nkCurly, r.info, setType)
for i in countup(1, sonsLen(r) - 1):
var it = r.sons[i]
case it.kind
of nkOfBranch:
result = lookupInRecordAndBuildCheck(c, n, lastSon(it), field, check)
if result == nil:
for j in 0..sonsLen(it)-2: addSon(s, copyTree(it.sons[j]))
else:
if check == nil:
check = newNodeI(nkCheckedFieldExpr, n.info)
addSon(check, ast.emptyNode) # make space for access node
s = newNodeIT(nkCurly, n.info, setType)
for j in countup(0, sonsLen(it) - 2): addSon(s, copyTree(it.sons[j]))
var inExpr = newNodeIT(nkCall, n.info, getSysType(tyBool))
addSon(inExpr, newSymNode(ast.opContains, n.info))
addSon(inExpr, s)
addSon(inExpr, copyTree(r.sons[0]))
addSon(check, inExpr)
#addSon(check, semExpr(c, inExpr))
return
of nkElse:
result = lookupInRecordAndBuildCheck(c, n, lastSon(it), field, check)
if result != nil:
if check == nil:
check = newNodeI(nkCheckedFieldExpr, n.info)
addSon(check, ast.emptyNode) # make space for access node
var inExpr = newNodeIT(nkCall, n.info, getSysType(tyBool))
addSon(inExpr, newSymNode(ast.opContains, n.info))
addSon(inExpr, s)
addSon(inExpr, copyTree(r.sons[0]))
var notExpr = newNodeIT(nkCall, n.info, getSysType(tyBool))
addSon(notExpr, newSymNode(ast.opNot, n.info))
addSon(notExpr, inExpr)
addSon(check, notExpr)
return
else: illFormedAst(it)
of nkSym:
if r.sym.name.id == field.id: result = r.sym
else: illFormedAst(n)
proc makeDeref(n: PNode): PNode =
var t = skipTypes(n.typ, {tyGenericInst})
result = n
if t.kind == tyVar:
result = newNodeIT(nkHiddenDeref, n.info, t.sons[0])
addSon(result, n)
t = skipTypes(t.sons[0], {tyGenericInst})
while t.kind in {tyPtr, tyRef}:
var a = result
let baseTyp = t.lastSon
result = newNodeIT(nkHiddenDeref, n.info, baseTyp)
addSon(result, a)
t = skipTypes(baseTyp, {tyGenericInst})
const
tyTypeParamsHolders = {tyGenericInst, tyCompositeTypeClass}
tyDotOpTransparent = {tyVar, tyPtr, tyRef}
proc readTypeParameter(c: PContext, typ: PType,
paramName: PIdent, info: TLineInfo): PNode =
let ty = if typ.kind == tyGenericInst: typ.skipGenericAlias
else: (internalAssert(typ.kind == tyCompositeTypeClass);
typ.sons[1].skipGenericAlias)
let tbody = ty.sons[0]
for s in countup(0, tbody.len-2):
let tParam = tbody.sons[s]
if tParam.sym.name.id == paramName.id:
let rawTyp = ty.sons[s + 1]
if rawTyp.kind == tyStatic:
return rawTyp.n
else:
let foundTyp = makeTypeDesc(c, rawTyp)
return newSymNode(copySym(tParam.sym).linkTo(foundTyp), info)
#echo "came here: returned nil"
proc semSym(c: PContext, n: PNode, s: PSym, flags: TExprFlags): PNode =
case s.kind
of skConst:
markUsed(n.info, s)
styleCheckUse(n.info, s)
case skipTypes(s.typ, abstractInst-{tyTypeDesc}).kind
of tyNil, tyChar, tyInt..tyInt64, tyFloat..tyFloat128,
tyTuple, tySet, tyUInt..tyUInt64:
if s.magic == mNone: result = inlineConst(n, s)
else: result = newSymNode(s, n.info)
of tyArrayConstr, tySequence:
# Consider::
# const x = []
# proc p(a: openarray[int])
# proc q(a: openarray[char])
# p(x)
# q(x)
#
# It is clear that ``[]`` means two totally different things. Thus, we
# copy `x`'s AST into each context, so that the type fixup phase can
# deal with two different ``[]``.
if s.ast.len == 0: result = inlineConst(n, s)
else: result = newSymNode(s, n.info)
else:
result = newSymNode(s, n.info)
of skMacro:
if efNoEvaluateGeneric in flags and s.ast[genericParamsPos].len > 0:
markUsed(n.info, s)
styleCheckUse(n.info, s)
result = newSymNode(s, n.info)
else:
result = semMacroExpr(c, n, n, s, flags)
of skTemplate:
if efNoEvaluateGeneric in flags and s.ast[genericParamsPos].len > 0:
markUsed(n.info, s)
styleCheckUse(n.info, s)
result = newSymNode(s, n.info)
else:
result = semTemplateExpr(c, n, s, flags)
of skParam:
markUsed(n.info, s)
styleCheckUse(n.info, s)
if s.typ.kind == tyStatic and s.typ.n != nil:
# XXX see the hack in sigmatch.nim ...
return s.typ.n
elif sfGenSym in s.flags:
if c.p.wasForwarded:
# gensym'ed parameters that nevertheless have been forward declared
# need a special fixup:
let realParam = c.p.owner.typ.n[s.position+1]
internalAssert realParam.kind == nkSym and realParam.sym.kind == skParam
return newSymNode(c.p.owner.typ.n[s.position+1].sym, n.info)
elif c.p.owner.kind == skMacro:
# gensym'ed macro parameters need a similar hack (see bug #1944):
var u = searchInScopes(c, s.name)
internalAssert u != nil and u.kind == skParam and u.owner == s.owner
return newSymNode(u, n.info)
result = newSymNode(s, n.info)
of skVar, skLet, skResult, skForVar:
if s.magic == mNimvm:
localError(n.info, "illegal context for 'nimvm' magic")
markUsed(n.info, s)
styleCheckUse(n.info, s)
result = newSymNode(s, n.info)
# We cannot check for access to outer vars for example because it's still
# not sure the symbol really ends up being used:
# var len = 0 # but won't be called
# genericThatUsesLen(x) # marked as taking a closure?
of skGenericParam:
styleCheckUse(n.info, s)
if s.typ.kind == tyStatic:
result = newSymNode(s, n.info)
result.typ = s.typ
elif s.ast != nil:
result = semExpr(c, s.ast)
else:
n.typ = s.typ
return n
of skType:
markUsed(n.info, s)
styleCheckUse(n.info, s)
if s.typ.kind == tyStatic and s.typ.n != nil:
return s.typ.n
result = newSymNode(s, n.info)
result.typ = makeTypeDesc(c, s.typ)
of skField:
var p = c.p
while p != nil and p.selfSym == nil:
p = p.next
if p != nil and p.selfSym != nil:
var ty = skipTypes(p.selfSym.typ, {tyGenericInst, tyVar, tyPtr, tyRef})
while tfBorrowDot in ty.flags: ty = ty.skipTypes({tyDistinct})
var check: PNode = nil
if ty.kind == tyObject:
while true:
check = nil
let f = lookupInRecordAndBuildCheck(c, n, ty.n, s.name, check)
if f != nil and fieldVisible(c, f):
# is the access to a public field or in the same module or in a friend?
doAssert f == s
markUsed(n.info, f)
styleCheckUse(n.info, f)
result = newNodeIT(nkDotExpr, n.info, f.typ)
result.add makeDeref(newSymNode(p.selfSym))
result.add newSymNode(f) # we now have the correct field
if check != nil:
check.sons[0] = result
check.typ = result.typ
result = check
return result
if ty.sons[0] == nil: break
ty = skipTypes(ty.sons[0], {tyGenericInst})
# old code, not sure if it's live code:
markUsed(n.info, s)
styleCheckUse(n.info, s)
result = newSymNode(s, n.info)
else:
markUsed(n.info, s)
styleCheckUse(n.info, s)
result = newSymNode(s, n.info)
proc builtinFieldAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
## returns nil if it's not a built-in field access
checkSonsLen(n, 2)
# tests/bind/tbindoverload.nim wants an early exit here, but seems to
# work without now. template/tsymchoicefield doesn't like an early exit
# here at all!
#if isSymChoice(n.sons[1]): return
var s = qualifiedLookUp(c, n, {checkAmbiguity, checkUndeclared, checkModule})
if s != nil:
if s.kind in OverloadableSyms:
result = symChoice(c, n, s, scClosed)
if result.kind == nkSym: result = semSym(c, n, s, flags)
else:
markUsed(n.sons[1].info, s)
result = semSym(c, n, s, flags)
styleCheckUse(n.sons[1].info, s)
return
n.sons[0] = semExprWithType(c, n.sons[0], flags+{efDetermineType})
#restoreOldStyleType(n.sons[0])
var i = considerQuotedIdent(n.sons[1])
var ty = n.sons[0].typ
var f: PSym = nil
result = nil
if isTypeExpr(n.sons[0]) or (ty.kind == tyTypeDesc and ty.base.kind != tyNone):
if ty.kind == tyTypeDesc: ty = ty.base
ty = ty.skipTypes(tyDotOpTransparent)
case ty.kind
of tyEnum:
# look up if the identifier belongs to the enum:
while ty != nil:
f = getSymFromList(ty.n, i)
if f != nil: break
ty = ty.sons[0] # enum inheritance
if f != nil:
result = newSymNode(f)
result.info = n.info
result.typ = ty
markUsed(n.info, f)
styleCheckUse(n.info, f)
return
of tyTypeParamsHolders:
return readTypeParameter(c, ty, i, n.info)
of tyObject, tyTuple:
if ty.n != nil and ty.n.kind == nkRecList:
for field in ty.n:
if field.sym.name == i:
n.typ = newTypeWithSons(c, tyFieldAccessor, @[ty, field.sym.typ])
n.typ.n = copyTree(n)
return n
else:
# echo "TYPE FIELD ACCESS"
# debug ty
return
# XXX: This is probably not relevant any more
# reset to prevent 'nil' bug: see "tests/reject/tenumitems.nim":
ty = n.sons[0].typ
return nil
ty = skipTypes(ty, {tyGenericInst, tyVar, tyPtr, tyRef})
while tfBorrowDot in ty.flags: ty = ty.skipTypes({tyDistinct})
var check: PNode = nil
if ty.kind == tyObject:
while true:
check = nil
f = lookupInRecordAndBuildCheck(c, n, ty.n, i, check)
if f != nil: break
if ty.sons[0] == nil: break
ty = skipTypes(ty.sons[0], {tyGenericInst})
if f != nil:
if fieldVisible(c, f):
# is the access to a public field or in the same module or in a friend?
markUsed(n.sons[1].info, f)
styleCheckUse(n.sons[1].info, f)
n.sons[0] = makeDeref(n.sons[0])
n.sons[1] = newSymNode(f) # we now have the correct field
n.typ = f.typ
if check == nil:
result = n
else:
check.sons[0] = n
check.typ = n.typ
result = check
elif ty.kind == tyTuple and ty.n != nil:
f = getSymFromList(ty.n, i)
if f != nil:
markUsed(n.sons[1].info, f)
styleCheckUse(n.sons[1].info, f)
n.sons[0] = makeDeref(n.sons[0])
n.sons[1] = newSymNode(f)
n.typ = f.typ
result = n
# we didn't find any field, let's look for a generic param
if result == nil:
let t = n.sons[0].typ.skipTypes(tyDotOpTransparent)
if t.kind in tyTypeParamsHolders:
result = readTypeParameter(c, t, i, n.info)
proc dotTransformation(c: PContext, n: PNode): PNode =
if isSymChoice(n.sons[1]):
result = newNodeI(nkDotCall, n.info)
addSon(result, n.sons[1])
addSon(result, copyTree(n[0]))
else:
var i = considerQuotedIdent(n.sons[1])
result = newNodeI(nkDotCall, n.info)
result.flags.incl nfDotField
addSon(result, newIdentNode(i, n[1].info))
addSon(result, copyTree(n[0]))
proc semFieldAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
# this is difficult, because the '.' is used in many different contexts
# in Nim. We first allow types in the semantic checking.
result = builtinFieldAccess(c, n, flags)
if result == nil:
result = dotTransformation(c, n)
proc buildOverloadedSubscripts(n: PNode, ident: PIdent): PNode =
result = newNodeI(nkCall, n.info)
result.add(newIdentNode(ident, n.info))
for i in 0 .. n.len-1: result.add(n[i])
proc semDeref(c: PContext, n: PNode): PNode =
checkSonsLen(n, 1)
n.sons[0] = semExprWithType(c, n.sons[0])
result = n
var t = skipTypes(n.sons[0].typ, {tyGenericInst, tyVar})
case t.kind
of tyRef, tyPtr: n.typ = t.lastSon
else: result = nil
#GlobalError(n.sons[0].info, errCircumNeedsPointer)
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
if sonsLen(n) == 1:
let x = semDeref(c, n)
if x == nil: return nil
result = newNodeIT(nkDerefExpr, x.info, x.typ)
result.add(x[0])
return
checkMinSonsLen(n, 2)
# make sure we don't evaluate generic macros/templates
n.sons[0] = semExprWithType(c, n.sons[0],
{efNoProcvarCheck, efNoEvaluateGeneric})
let arr = skipTypes(n.sons[0].typ, {tyGenericInst, tyVar, tyPtr, tyRef})
case arr.kind
of tyArray, tyOpenArray, tyVarargs, tyArrayConstr, tySequence, tyString,
tyCString:
if n.len != 2: return nil
n.sons[0] = makeDeref(n.sons[0])
c.p.bracketExpr = n.sons[0]
for i in countup(1, sonsLen(n) - 1):
n.sons[i] = semExprWithType(c, n.sons[i],
flags*{efInTypeof, efDetermineType})
var indexType = if arr.kind == tyArray: arr.sons[0] else: getSysType(tyInt)
var arg = indexTypesMatch(c, indexType, n.sons[1].typ, n.sons[1])
if arg != nil:
n.sons[1] = arg
result = n
result.typ = elemType(arr)
#GlobalError(n.info, errIndexTypesDoNotMatch)
of tyTypeDesc:
# The result so far is a tyTypeDesc bound
# a tyGenericBody. The line below will substitute
# it with the instantiated type.
result = n
result.typ = makeTypeDesc(c, semTypeNode(c, n, nil))
#result = symNodeFromType(c, semTypeNode(c, n, nil), n.info)
of tyTuple:
checkSonsLen(n, 2)
n.sons[0] = makeDeref(n.sons[0])
c.p.bracketExpr = n.sons[0]
# [] operator for tuples requires constant expression:
n.sons[1] = semConstExpr(c, n.sons[1])
if skipTypes(n.sons[1].typ, {tyGenericInst, tyRange, tyOrdinal}).kind in
{tyInt..tyInt64}:
var idx = getOrdValue(n.sons[1])
if idx >= 0 and idx < sonsLen(arr): n.typ = arr.sons[int(idx)]
else: localError(n.info, errInvalidIndexValueForTuple)
else:
localError(n.info, errIndexTypesDoNotMatch)
result = n
else:
let s = if n.sons[0].kind == nkSym: n.sons[0].sym
elif n[0].kind in nkSymChoices: n.sons[0][0].sym
else: nil
if s != nil:
case s.kind
of skProc, skMethod, skConverter, skIterator:
# type parameters: partial generic specialization
n.sons[0] = semSymGenericInstantiation(c, n.sons[0], s)
result = explicitGenericInstantiation(c, n, s)
of skMacro, skTemplate:
if efInCall in flags:
# We are processing macroOrTmpl[] in macroOrTmpl[](...) call.
# Return as is, so it can be transformed into complete macro or
# template call in semIndirectOp caller.
result = n
else:
# We are processing macroOrTmpl[] not in call. Transform it to the
# macro or template call with generic arguments here.
n.kind = nkCall
case s.kind
of skMacro: result = semMacroExpr(c, n, n, s, flags)
of skTemplate: result = semTemplateExpr(c, n, s, flags)
else: discard
of skType:
result = symNodeFromType(c, semTypeNode(c, n, nil), n.info)
else:
c.p.bracketExpr = n.sons[0]
else:
c.p.bracketExpr = n.sons[0]
proc semArrayAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
let oldBracketExpr = c.p.bracketExpr
result = semSubscript(c, n, flags)
if result == nil:
# overloaded [] operator:
result = semExpr(c, buildOverloadedSubscripts(n, getIdent"[]"))
c.p.bracketExpr = oldBracketExpr
proc propertyWriteAccess(c: PContext, n, nOrig, a: PNode): PNode =
var id = considerQuotedIdent(a[1])
var setterId = newIdentNode(getIdent(id.s & '='), n.info)
# a[0] is already checked for semantics, that does ``builtinFieldAccess``
# this is ugly. XXX Semantic checking should use the ``nfSem`` flag for
# nodes?
let aOrig = nOrig[0]
result = newNode(nkCall, n.info, sons = @[setterId, a[0], semExpr(c, n[1])])
result.flags.incl nfDotSetter
let orig = newNode(nkCall, n.info, sons = @[setterId, aOrig[0], nOrig[1]])
result = semOverloadedCallAnalyseEffects(c, result, orig, {})
if result != nil:
result = afterCallActions(c, result, nOrig, {})
#fixAbstractType(c, result)
#analyseIfAddressTakenInCall(c, result)
proc takeImplicitAddr(c: PContext, n: PNode): PNode =
case n.kind
of nkHiddenAddr, nkAddr: return n
of nkHiddenDeref, nkDerefExpr: return n.sons[0]
of nkBracketExpr:
if len(n) == 1: return n.sons[0]
else: discard
var valid = isAssignable(c, n)
if valid != arLValue:
if valid == arLocalLValue:
localError(n.info, errXStackEscape, renderTree(n, {renderNoComments}))
else:
localError(n.info, errExprHasNoAddress)
result = newNodeIT(nkHiddenAddr, n.info, makePtrType(c, n.typ))
result.add(n)
proc asgnToResultVar(c: PContext, n, le, ri: PNode) {.inline.} =
if le.kind == nkHiddenDeref:
var x = le.sons[0]
if x.typ.kind == tyVar and x.kind == nkSym and x.sym.kind == skResult:
n.sons[0] = x # 'result[]' --> 'result'
n.sons[1] = takeImplicitAddr(c, ri)
x.typ.flags.incl tfVarIsPtr
template resultTypeIsInferrable(typ: PType): untyped =
typ.isMetaType and typ.kind != tyTypeDesc
proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode =
checkSonsLen(n, 2)
var a = n.sons[0]
case a.kind
of nkDotExpr:
# r.f = x
# --> `f=` (r, x)
let nOrig = n.copyTree
a = builtinFieldAccess(c, a, {efLValue})
if a == nil:
a = propertyWriteAccess(c, n, nOrig, n[0])
if a != nil: return a
# we try without the '='; proc that return 'var' or macros are still
# possible:
a = dotTransformation(c, n[0])
if a.kind == nkDotCall:
a.kind = nkCall
a = semExprWithType(c, a, {efLValue})
of nkBracketExpr:
# a[i] = x
# --> `[]=`(a, i, x)
let oldBracketExpr = c.p.bracketExpr
a = semSubscript(c, a, {efLValue})
if a == nil:
result = buildOverloadedSubscripts(n.sons[0], getIdent"[]=")
add(result, n[1])
if mode == noOverloadedSubscript:
bracketNotFoundError(c, result)
return n
else:
result = semExprNoType(c, result)
c.p.bracketExpr = oldBracketExpr
return result
c.p.bracketExpr = oldBracketExpr
of nkCurlyExpr:
# a{i} = x --> `{}=`(a, i, x)
result = buildOverloadedSubscripts(n.sons[0], getIdent"{}=")
add(result, n[1])
return semExprNoType(c, result)
of nkPar:
if a.len >= 2:
# 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(n, c.p.owner))
else:
a = semExprWithType(c, a, {efLValue})
else:
a = semExprWithType(c, a, {efLValue})
n.sons[0] = a
# a = b # both are vars, means: a[] = b[]
# a = b # b no 'var T' means: a = addr(b)
var le = a.typ
if skipTypes(le, {tyGenericInst}).kind != tyVar and
isAssignable(c, a) == arNone:
# Direct assignment to a discriminant is allowed!
localError(a.info, errXCannotBeAssignedTo,
renderTree(a, {renderNoComments}))
else:
let
lhs = n.sons[0]
lhsIsResult = lhs.kind == nkSym and lhs.sym.kind == skResult
var
rhs = semExprWithType(c, n.sons[1],
if lhsIsResult: {efAllowDestructor} else: {})
if lhsIsResult:
n.typ = enforceVoidContext
if c.p.owner.kind != skMacro and resultTypeIsInferrable(lhs.sym.typ):
if cmpTypes(c, lhs.typ, rhs.typ) == isGeneric:
internalAssert c.p.resultSym != nil
lhs.typ = rhs.typ
c.p.resultSym.typ = rhs.typ
c.p.owner.typ.sons[0] = rhs.typ
else:
typeMismatch(n, lhs.typ, rhs.typ)
n.sons[1] = fitNode(c, le, rhs)
if tfHasAsgn in lhs.typ.flags and not lhsIsResult and
mode != noOverloadedAsgn:
return overloadedAsgn(c, lhs, n.sons[1])
fixAbstractType(c, n)
asgnToResultVar(c, n, n.sons[0], n.sons[1])
result = n
proc semReturn(c: PContext, n: PNode): PNode =
result = n
checkSonsLen(n, 1)
if c.p.owner.kind in {skConverter, skMethod, skProc, skMacro} or (
c.p.owner.kind == skIterator and c.p.owner.typ.callConv == ccClosure):
if n.sons[0].kind != nkEmpty:
# transform ``return expr`` to ``result = expr; return``
if c.p.resultSym != nil:
var a = newNodeI(nkAsgn, n.sons[0].info)
addSon(a, newSymNode(c.p.resultSym))
addSon(a, n.sons[0])
n.sons[0] = semAsgn(c, a)
# optimize away ``result = result``:
if n[0][1].kind == nkSym and n[0][1].sym == c.p.resultSym:
n.sons[0] = ast.emptyNode
else:
localError(n.info, errNoReturnTypeDeclared)
else:
localError(n.info, errXNotAllowedHere, "\'return\'")
proc semProcBody(c: PContext, n: PNode): PNode =
openScope(c)
result = semExpr(c, n)
if c.p.resultSym != nil and not isEmptyType(result.typ):
# transform ``expr`` to ``result = expr``, but not if the expr is already
# ``result``:
if result.kind == nkSym and result.sym == c.p.resultSym:
discard
elif result.kind == nkNilLit:
# or ImplicitlyDiscardable(result):
# new semantic: 'result = x' triggers the void context
result.typ = nil
elif result.kind == nkStmtListExpr and result.typ.kind == tyNil:
# to keep backwards compatibility bodies like:
# nil
# # comment
# are not expressions:
fixNilType(result)
else:
var a = newNodeI(nkAsgn, n.info, 2)
a.sons[0] = newSymNode(c.p.resultSym)
a.sons[1] = result
result = semAsgn(c, a)
else:
discardCheck(c, result)
if c.p.owner.kind notin {skMacro, skTemplate} and
c.p.resultSym != nil and c.p.resultSym.typ.isMetaType:
if isEmptyType(result.typ):
# we inferred a 'void' return type:
c.p.resultSym.typ = errorType(c)
c.p.owner.typ.sons[0] = nil
else:
localError(c.p.resultSym.info, errCannotInferReturnType)
closeScope(c)
proc semYieldVarResult(c: PContext, n: PNode, restype: PType) =
var t = skipTypes(restype, {tyGenericInst})
case t.kind
of tyVar:
n.sons[0] = takeImplicitAddr(c, n.sons[0])
of tyTuple:
for i in 0.. <t.sonsLen:
var e = skipTypes(t.sons[i], {tyGenericInst})
if e.kind == tyVar:
if n.sons[0].kind == nkPar:
n.sons[0].sons[i] = takeImplicitAddr(c, n.sons[0].sons[i])
elif n.sons[0].kind in {nkHiddenStdConv, nkHiddenSubConv} and
n.sons[0].sons[1].kind == nkPar:
var a = n.sons[0].sons[1]
a.sons[i] = takeImplicitAddr(c, a.sons[i])
else:
localError(n.sons[0].info, errXExpected, "tuple constructor")
else: discard
proc semYield(c: PContext, n: PNode): PNode =
result = n
checkSonsLen(n, 1)
if c.p.owner == nil or c.p.owner.kind != skIterator:
localError(n.info, errYieldNotAllowedHere)
elif c.p.inTryStmt > 0 and c.p.owner.typ.callConv != ccInline:
localError(n.info, errYieldNotAllowedInTryStmt)
elif n.sons[0].kind != nkEmpty:
n.sons[0] = semExprWithType(c, n.sons[0]) # check for type compatibility:
var iterType = c.p.owner.typ
let restype = iterType.sons[0]
if restype != nil:
if restype.kind != tyExpr:
n.sons[0] = fitNode(c, restype, n.sons[0])
if n.sons[0].typ == nil: internalError(n.info, "semYield")
if resultTypeIsInferrable(restype):
let inferred = n.sons[0].typ
iterType.sons[0] = inferred
semYieldVarResult(c, n, restype)
else:
localError(n.info, errCannotReturnExpr)
elif c.p.owner.typ.sons[0] != nil:
localError(n.info, errGenerated, "yield statement must yield a value")
proc lookUpForDefined(c: PContext, i: PIdent, onlyCurrentScope: bool): PSym =
if onlyCurrentScope:
result = localSearchInScope(c, i)
else:
result = searchInScopes(c, i) # no need for stub loading
proc lookUpForDefined(c: PContext, n: PNode, onlyCurrentScope: bool): PSym =
case n.kind
of nkIdent:
result = lookUpForDefined(c, n.ident, onlyCurrentScope)
of nkDotExpr:
result = nil
if onlyCurrentScope: return
checkSonsLen(n, 2)
var m = lookUpForDefined(c, n.sons[0], onlyCurrentScope)
if m != nil and m.kind == skModule:
let ident = considerQuotedIdent(n[1])
if m == c.module:
result = strTableGet(c.topLevelScope.symbols, ident)
else:
result = strTableGet(m.tab, ident)
of nkAccQuoted:
result = lookUpForDefined(c, considerQuotedIdent(n), onlyCurrentScope)
of nkSym:
result = n.sym
of nkOpenSymChoice, nkClosedSymChoice:
result = n.sons[0].sym
else:
localError(n.info, errIdentifierExpected, renderTree(n))
result = nil
proc semDefined(c: PContext, n: PNode, onlyCurrentScope: bool): PNode =
checkSonsLen(n, 2)
# we replace this node by a 'true' or 'false' node:
result = newIntNode(nkIntLit, 0)
if not onlyCurrentScope and considerQuotedIdent(n[0]).s == "defined":
if n.sons[1].kind != nkIdent:
localError(n.info, "obsolete usage of 'defined', use 'declared' instead")
elif condsyms.isDefined(n.sons[1].ident):
result.intVal = 1
elif lookUpForDefined(c, n.sons[1], onlyCurrentScope) != nil:
result.intVal = 1
result.info = n.info
result.typ = getSysType(tyBool)
proc expectMacroOrTemplateCall(c: PContext, n: PNode): PSym =
## The argument to the proc should be nkCall(...) or similar
## Returns the macro/template symbol
if isCallExpr(n):
var expandedSym = qualifiedLookUp(c, n[0], {checkUndeclared})
if expandedSym == nil:
localError(n.info, errUndeclaredIdentifier, n[0].renderTree)
return errorSym(c, n[0])
if expandedSym.kind notin {skMacro, skTemplate}:
localError(n.info, errXisNoMacroOrTemplate, expandedSym.name.s)
return errorSym(c, n[0])
result = expandedSym
else:
localError(n.info, errXisNoMacroOrTemplate, n.renderTree)
result = errorSym(c, n)
proc expectString(c: PContext, n: PNode): string =
var n = semConstExpr(c, n)
if n.kind in nkStrKinds:
return n.strVal
else:
localError(n.info, errStringLiteralExpected)
proc getMagicSym(magic: TMagic): PSym =
result = newSym(skProc, getIdent($magic), systemModule, gCodegenLineInfo)
result.magic = magic
proc newAnonSym(kind: TSymKind, info: TLineInfo,
owner = getCurrOwner()): PSym =
result = newSym(kind, idAnon, owner, info)
result.flags = {sfGenSym}
proc semExpandToAst(c: PContext, n: PNode): PNode =
let macroCall = n[1]
let expandedSym = expectMacroOrTemplateCall(c, macroCall)
if expandedSym.kind == skError: return n
macroCall.sons[0] = newSymNode(expandedSym, macroCall.info)
markUsed(n.info, expandedSym)
styleCheckUse(n.info, expandedSym)
for i in countup(1, macroCall.len-1):
#if macroCall.sons[0].typ.sons[i].kind != tyExpr:
macroCall.sons[i] = semExprWithType(c, macroCall[i], {})
# Preserve the magic symbol in order to be handled in evals.nim
internalAssert n.sons[0].sym.magic == mExpandToAst
#n.typ = getSysSym("NimNode").typ # expandedSym.getReturnType
n.typ = if getCompilerProc("NimNode") != nil: sysTypeFromName"NimNode"
else: sysTypeFromName"PNimrodNode"
result = n
proc semExpandToAst(c: PContext, n: PNode, magicSym: PSym,
flags: TExprFlags = {}): PNode =
if sonsLen(n) == 2:
n.sons[0] = newSymNode(magicSym, n.info)
result = semExpandToAst(c, n)
else:
result = semDirectOp(c, n, flags)
proc processQuotations(n: var PNode, op: string,
quotes: var seq[PNode],
ids: var seq[PNode]) =
template returnQuote(q) =
quotes.add q
n = newIdentNode(getIdent($quotes.len), n.info)
ids.add n
return
if n.kind == nkPrefix:
checkSonsLen(n, 2)
if n[0].kind == nkIdent:
var examinedOp = n[0].ident.s
if examinedOp == op:
returnQuote n[1]
elif examinedOp.startsWith(op):
n.sons[0] = newIdentNode(getIdent(examinedOp.substr(op.len)), n.info)
elif n.kind == nkAccQuoted and op == "``":
returnQuote n[0]
for i in 0 .. <n.safeLen:
processQuotations(n.sons[i], op, quotes, ids)
proc semQuoteAst(c: PContext, n: PNode): PNode =
internalAssert n.len == 2 or n.len == 3
# We transform the do block into a template with a param for
# each interpolation. We'll pass this template to getAst.
var
doBlk = n{-1}
op = if n.len == 3: expectString(c, n[1]) else: "``"
quotes = newSeq[PNode](1)
# the quotes will be added to a nkCall statement
# leave some room for the callee symbol
ids = newSeq[PNode]()
# this will store the generated param names
if doBlk.kind != nkDo:
localError(n.info, errXExpected, "block")
processQuotations(doBlk.sons[bodyPos], op, quotes, ids)
doBlk.sons[namePos] = newAnonSym(skTemplate, n.info).newSymNode
if ids.len > 0:
doBlk.sons[paramsPos] = newNodeI(nkFormalParams, n.info)
doBlk[paramsPos].add getSysSym("stmt").newSymNode # return type
ids.add getSysSym("expr").newSymNode # params type
ids.add emptyNode # no default value
doBlk[paramsPos].add newNode(nkIdentDefs, n.info, ids)
var tmpl = semTemplateDef(c, doBlk)
quotes[0] = tmpl[namePos]
result = newNode(nkCall, n.info, @[
getMagicSym(mExpandToAst).newSymNode,
newNode(nkCall, n.info, quotes)])
result = semExpandToAst(c, result)
proc tryExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
# watch out, hacks ahead:
let oldErrorCount = msgs.gErrorCounter
let oldErrorMax = msgs.gErrorMax
let oldCompilesId = c.compilesContextId
inc c.compilesContextIdGenerator
c.compilesContextId = c.compilesContextIdGenerator
# do not halt after first error:
msgs.gErrorMax = high(int)
# open a scope for temporary symbol inclusions:
let oldScope = c.currentScope
openScope(c)
let oldOwnerLen = len(gOwners)
let oldGenerics = c.generics
let oldErrorOutputs = errorOutputs
errorOutputs = {}
let oldContextLen = msgs.getInfoContextLen()
let oldInGenericContext = c.inGenericContext
let oldInUnrolledContext = c.inUnrolledContext
let oldInGenericInst = c.inGenericInst
let oldProcCon = c.p
c.generics = @[]
var err: string
try:
result = semExpr(c, n, flags)
if msgs.gErrorCounter != oldErrorCount: result = nil
except ERecoverableError:
if optReportConceptFailures in gGlobalOptions:
err = getCurrentExceptionMsg()
# undo symbol table changes (as far as it's possible):
c.compilesContextId = oldCompilesId
c.generics = oldGenerics
c.inGenericContext = oldInGenericContext
c.inUnrolledContext = oldInUnrolledContext
c.inGenericInst = oldInGenericInst
c.p = oldProcCon
msgs.setInfoContextLen(oldContextLen)
setLen(gOwners, oldOwnerLen)
c.currentScope = oldScope
errorOutputs = oldErrorOutputs
msgs.gErrorCounter = oldErrorCount
msgs.gErrorMax = oldErrorMax
if optReportConceptFailures in gGlobalOptions and not err.isNil:
localError(n.info, err)
proc semCompiles(c: PContext, n: PNode, flags: TExprFlags): PNode =
# we replace this node by a 'true' or 'false' node:
if sonsLen(n) != 2: return semDirectOp(c, n, flags)
result = newIntNode(nkIntLit, ord(tryExpr(c, n[1], flags) != nil))
result.info = n.info
result.typ = getSysType(tyBool)
proc semShallowCopy(c: PContext, n: PNode, flags: TExprFlags): PNode =
if sonsLen(n) == 3:
# XXX ugh this is really a hack: shallowCopy() can be overloaded only
# with procs that take not 2 parameters:
result = newNodeI(nkFastAsgn, n.info)
result.add(n[1])
result.add(n[2])
result = semAsgn(c, result)
else:
result = semDirectOp(c, n, flags)
proc createFlowVar(c: PContext; t: PType; info: TLineInfo): PType =
result = newType(tyGenericInvocation, c.module)
addSonSkipIntLit(result, magicsys.getCompilerProc("FlowVar").typ)
addSonSkipIntLit(result, t)
result = instGenericContainer(c, info, result, allowMetaTypes = false)
proc instantiateCreateFlowVarCall(c: PContext; t: PType;
info: TLineInfo): PSym =
let sym = magicsys.getCompilerProc("nimCreateFlowVar")
if sym == nil:
localError(info, errSystemNeeds, "nimCreateFlowVar")
var bindings: TIdTable
initIdTable(bindings)
bindings.idTablePut(sym.ast[genericParamsPos].sons[0].typ, t)
result = c.semGenerateInstance(c, sym, bindings, info)
# since it's an instantiation, we unmark it as a compilerproc. Otherwise
# codegen would fail:
if sfCompilerProc in result.flags:
result.flags = result.flags - {sfCompilerProc, sfExportC, sfImportC}
result.loc.r = nil
proc setMs(n: PNode, s: PSym): PNode =
result = n
n.sons[0] = newSymNode(s)
n.sons[0].info = n.info
proc semMagic(c: PContext, n: PNode, s: PSym, flags: TExprFlags): PNode =
# this is a hotspot in the compiler!
# DON'T forget to update ast.SpecialSemMagics if you add a magic here!
result = n
case s.magic # magics that need special treatment
of mAddr:
checkSonsLen(n, 2)
result = semAddr(c, n.sons[1], s.name.s == "unsafeAddr")
of mTypeOf:
checkSonsLen(n, 2)
result = semTypeOf(c, n.sons[1])
#of mArrGet: result = semArrGet(c, n, flags)
#of mArrPut: result = semArrPut(c, n, flags)
#of mAsgn: result = semAsgnOpr(c, n)
of mDefined: result = semDefined(c, setMs(n, s), false)
of mDefinedInScope: result = semDefined(c, setMs(n, s), true)
of mCompiles: result = semCompiles(c, setMs(n, s), flags)
of mLow: result = semLowHigh(c, setMs(n, s), mLow)
of mHigh: result = semLowHigh(c, setMs(n, s), mHigh)
of mSizeOf: result = semSizeof(c, setMs(n, s))
of mIs: result = semIs(c, setMs(n, s))
of mOf: result = semOf(c, setMs(n, s))
of mShallowCopy: result = semShallowCopy(c, n, flags)
of mExpandToAst: result = semExpandToAst(c, n, s, flags)
of mQuoteAst: result = semQuoteAst(c, n)
of mAstToStr:
checkSonsLen(n, 2)
result = newStrNodeT(renderTree(n[1], {renderNoComments}), n)
result.typ = getSysType(tyString)
of mParallel:
if not experimentalMode(c):
localError(n.info, "use the {.experimental.} pragma to enable 'parallel'")
result = setMs(n, s)
var x = n.lastSon
if x.kind == nkDo: x = x.sons[bodyPos]
inc c.inParallelStmt
result.sons[1] = semStmt(c, x)
dec c.inParallelStmt
of mSpawn:
result = setMs(n, s)
for i in 1 .. <n.len:
result.sons[i] = semExpr(c, n.sons[i])
let typ = result[^1].typ
if not typ.isEmptyType:
if spawnResult(typ, c.inParallelStmt > 0) == srFlowVar:
result.typ = createFlowVar(c, typ, n.info)
else:
result.typ = typ
result.add instantiateCreateFlowVarCall(c, typ, n.info).newSymNode
else:
result.add emptyNode
of mProcCall:
result = setMs(n, s)
result.sons[1] = semExpr(c, n.sons[1])
result.typ = n[1].typ
of mPlugin:
# semDirectOp with conditional 'afterCallActions':
let nOrig = n.copyTree
#semLazyOpAux(c, n)
result = semOverloadedCallAnalyseEffects(c, n, nOrig, flags)
if result == nil:
result = errorNode(c, n)
else:
let callee = result.sons[0].sym
if callee.magic == mNone:
semFinishOperands(c, result)
activate(c, result)
fixAbstractType(c, result)
analyseIfAddressTakenInCall(c, result)
if callee.magic != mNone:
result = magicsAfterOverloadResolution(c, result, flags)
else:
result = semDirectOp(c, n, flags)
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
template setResult(e: untyped) =
if semCheck: result = semExpr(c, e) # do not open a new scope!
else: result = e
# Check if the node is "when nimvm"
# when nimvm:
# ...
# else:
# ...
var whenNimvm = false
var typ = commonTypeBegin
if n.sons.len == 2 and n.sons[0].kind == nkElifBranch and
n.sons[1].kind == nkElse:
let exprNode = n.sons[0].sons[0]
if exprNode.kind == nkIdent:
whenNimvm = lookUp(c, exprNode).magic == mNimvm
elif exprNode.kind == nkSym:
whenNimvm = exprNode.sym.magic == mNimvm
if whenNimvm: n.flags.incl nfLL
for i in countup(0, sonsLen(n) - 1):
var it = n.sons[i]
case it.kind
of nkElifBranch, nkElifExpr:
checkSonsLen(it, 2)
if whenNimvm:
if semCheck:
it.sons[1] = semExpr(c, it.sons[1])
typ = commonType(typ, it.sons[1].typ)
result = n # when nimvm is not elimited until codegen
else:
var e = semConstExpr(c, it.sons[0])
if e.kind != nkIntLit:
# can happen for cascading errors, assume false
# InternalError(n.info, "semWhen")
discard
elif e.intVal != 0 and result == nil:
setResult(it.sons[1])
of nkElse, nkElseExpr:
checkSonsLen(it, 1)
if result == nil or whenNimvm:
if semCheck:
it.sons[0] = semExpr(c, it.sons[0])
typ = commonType(typ, it.sons[0].typ)
if result == nil:
result = it.sons[0]
else: illFormedAst(n)
if result == nil:
result = newNodeI(nkEmpty, n.info)
if whenNimvm: result.typ = typ
# The ``when`` statement implements the mechanism for platform dependent
# code. Thus we try to ensure here consistent ID allocation after the
# ``when`` statement.
idSynchronizationPoint(200)
proc semSetConstr(c: PContext, n: PNode): PNode =
result = newNodeI(nkCurly, n.info)
result.typ = newTypeS(tySet, c)
if sonsLen(n) == 0:
rawAddSon(result.typ, newTypeS(tyEmpty, c))
else:
# only semantic checking for all elements, later type checking:
var typ: PType = nil
for i in countup(0, sonsLen(n) - 1):
if isRange(n.sons[i]):
checkSonsLen(n.sons[i], 3)
n.sons[i].sons[1] = semExprWithType(c, n.sons[i].sons[1])
n.sons[i].sons[2] = semExprWithType(c, n.sons[i].sons[2])
if typ == nil:
typ = skipTypes(n.sons[i].sons[1].typ,
{tyGenericInst, tyVar, tyOrdinal})
n.sons[i].typ = n.sons[i].sons[2].typ # range node needs type too
elif n.sons[i].kind == nkRange:
# already semchecked
if typ == nil:
typ = skipTypes(n.sons[i].sons[0].typ,
{tyGenericInst, tyVar, tyOrdinal})
else:
n.sons[i] = semExprWithType(c, n.sons[i])
if typ == nil:
typ = skipTypes(n.sons[i].typ, {tyGenericInst, tyVar, tyOrdinal})
if not isOrdinalType(typ):
localError(n.info, errOrdinalTypeExpected)
typ = makeRangeType(c, 0, MaxSetElements-1, n.info)
elif lengthOrd(typ) > MaxSetElements:
typ = makeRangeType(c, 0, MaxSetElements-1, n.info)
addSonSkipIntLit(result.typ, typ)
for i in countup(0, sonsLen(n) - 1):
var m: PNode
if isRange(n.sons[i]):
m = newNodeI(nkRange, n.sons[i].info)
addSon(m, fitNode(c, typ, n.sons[i].sons[1]))
addSon(m, fitNode(c, typ, n.sons[i].sons[2]))
elif n.sons[i].kind == nkRange: m = n.sons[i] # already semchecked
else:
m = fitNode(c, typ, n.sons[i])
addSon(result, m)
proc semTableConstr(c: PContext, n: PNode): PNode =
# we simply transform ``{key: value, key2, key3: value}`` to
# ``[(key, value), (key2, value2), (key3, value2)]``
result = newNodeI(nkBracket, n.info)
var lastKey = 0
for i in 0..n.len-1:
var x = n.sons[i]
if x.kind == nkExprColonExpr and sonsLen(x) == 2:
for j in countup(lastKey, i-1):
var pair = newNodeI(nkPar, x.info)
pair.add(n.sons[j])
pair.add(x[1])
result.add(pair)
var pair = newNodeI(nkPar, x.info)
pair.add(x[0])
pair.add(x[1])
result.add(pair)
lastKey = i+1
if lastKey != n.len: illFormedAst(n)
result = semExpr(c, result)
type
TParKind = enum
paNone, paSingle, paTupleFields, paTuplePositions
proc checkPar(n: PNode): TParKind =
var length = sonsLen(n)
if length == 0:
result = paTuplePositions # ()
elif length == 1:
if n.sons[0].kind == nkExprColonExpr: result = paTupleFields
else: result = paSingle # (expr)
else:
if n.sons[0].kind == nkExprColonExpr: result = paTupleFields
else: result = paTuplePositions
for i in countup(0, length - 1):
if result == paTupleFields:
if (n.sons[i].kind != nkExprColonExpr) or
not (n.sons[i].sons[0].kind in {nkSym, nkIdent}):
localError(n.sons[i].info, errNamedExprExpected)
return paNone
else:
if n.sons[i].kind == nkExprColonExpr:
localError(n.sons[i].info, errNamedExprNotAllowed)
return paNone
proc semTupleFieldsConstr(c: PContext, n: PNode, flags: TExprFlags): PNode =
result = newNodeI(nkPar, n.info)
var typ = newTypeS(tyTuple, c)
typ.n = newNodeI(nkRecList, n.info) # nkIdentDefs
var ids = initIntSet()
for i in countup(0, sonsLen(n) - 1):
if n[i].kind != nkExprColonExpr or n[i][0].kind notin {nkSym, nkIdent}:
illFormedAst(n.sons[i])
var id: PIdent
if n.sons[i].sons[0].kind == nkIdent: id = n.sons[i].sons[0].ident
else: id = n.sons[i].sons[0].sym.name
if containsOrIncl(ids, id.id):
localError(n.sons[i].info, errFieldInitTwice, id.s)
n.sons[i].sons[1] = semExprWithType(c, n.sons[i].sons[1],
flags*{efAllowDestructor})
var f = newSymS(skField, n.sons[i].sons[0], c)
f.typ = skipIntLit(n.sons[i].sons[1].typ)
f.position = i
rawAddSon(typ, f.typ)
addSon(typ.n, newSymNode(f))
n.sons[i].sons[0] = newSymNode(f)
addSon(result, n.sons[i])
result.typ = typ
proc semTuplePositionsConstr(c: PContext, n: PNode, flags: TExprFlags): PNode =
result = n # we don't modify n, but compute the type:
var typ = newTypeS(tyTuple, c) # leave typ.n nil!
for i in countup(0, sonsLen(n) - 1):
n.sons[i] = semExprWithType(c, n.sons[i], flags*{efAllowDestructor})
addSonSkipIntLit(typ, n.sons[i].typ)
result.typ = typ
proc isTupleType(n: PNode): bool =
if n.len == 0:
return false # don't interpret () as type
for i in countup(0, n.len - 1):
if n[i].typ == nil or n[i].typ.kind != tyTypeDesc:
return false
return true
proc checkInitialized(n: PNode, ids: IntSet, info: TLineInfo) =
case n.kind
of nkRecList:
for i in countup(0, sonsLen(n) - 1):
checkInitialized(n.sons[i], ids, info)
of nkRecCase:
if (n.sons[0].kind != nkSym): internalError(info, "checkInitialized")
checkInitialized(n.sons[0], ids, info)
when false:
# XXX we cannot check here, as we don't know the branch!
for i in countup(1, sonsLen(n) - 1):
case n.sons[i].kind
of nkOfBranch, nkElse: checkInitialized(lastSon(n.sons[i]), ids, info)
else: internalError(info, "checkInitialized")
of nkSym:
if {tfNotNil, tfNeedsInit} * n.sym.typ.flags != {} and
n.sym.name.id notin ids:
message(info, errGenerated, "field not initialized: " & n.sym.name.s)
else: internalError(info, "checkInitialized")
proc semObjConstr(c: PContext, n: PNode, flags: TExprFlags): PNode =
var t = semTypeNode(c, n.sons[0], nil)
result = n
result.typ = t
result.kind = nkObjConstr
t = skipTypes(t, {tyGenericInst})
if t.kind == tyRef: t = skipTypes(t.sons[0], {tyGenericInst})
if t.kind != tyObject:
localError(n.info, errGenerated, "object constructor needs an object type")
return
var objType = t
var ids = initIntSet()
for i in 1.. <n.len:
let it = n.sons[i]
if it.kind != nkExprColonExpr:
localError(n.info, errNamedExprExpected)
break
let id = considerQuotedIdent(it.sons[0])
if containsOrIncl(ids, id.id):
localError(it.info, errFieldInitTwice, id.s)
var e = semExprWithType(c, it.sons[1], flags*{efAllowDestructor})
var
check: PNode = nil
f: PSym
t = objType
while true:
check = nil
f = lookupInRecordAndBuildCheck(c, it, t.n, id, check)
if f != nil: break
if t.sons[0] == nil: break
t = skipTypes(t.sons[0], {tyGenericInst})
if f != nil and fieldVisible(c, f):
it.sons[0] = newSymNode(f)
e = fitNode(c, f.typ, e)
# small hack here in a nkObjConstr the ``nkExprColonExpr`` node can have
# 3 children the last being the field check
if check != nil:
check.sons[0] = it.sons[0]
it.add(check)
else:
localError(it.info, errUndeclaredFieldX, id.s)
it.sons[1] = e
# XXX object field name check for 'case objects' if the kind is static?
if tfNeedsInit in objType.flags:
while true:
checkInitialized(objType.n, ids, n.info)
if objType.sons[0] == nil: break
objType = skipTypes(objType.sons[0], {tyGenericInst})
proc semBlock(c: PContext, n: PNode): PNode =
result = n
inc(c.p.nestedBlockCounter)
checkSonsLen(n, 2)
openScope(c) # BUGFIX: label is in the scope of block!
if n.sons[0].kind != nkEmpty:
var labl = newSymG(skLabel, n.sons[0], c)
if sfGenSym notin labl.flags:
addDecl(c, labl)
n.sons[0] = newSymNode(labl, n.sons[0].info)
suggestSym(n.sons[0].info, labl)
styleCheckDef(labl)
n.sons[1] = semExpr(c, n.sons[1])
n.typ = n.sons[1].typ
if isEmptyType(n.typ): n.kind = nkBlockStmt
else: n.kind = nkBlockExpr
closeScope(c)
dec(c.p.nestedBlockCounter)
proc semExport(c: PContext, n: PNode): PNode =
var x = newNodeI(n.kind, n.info)
#let L = if n.kind == nkExportExceptStmt: L = 1 else: n.len
for i in 0.. <n.len:
let a = n.sons[i]
var o: TOverloadIter
var s = initOverloadIter(o, c, a)
if s == nil:
localError(a.info, errGenerated, "cannot export: " & renderTree(a))
elif s.kind == skModule:
# forward everything from that module:
strTableAdd(c.module.tab, s)
x.add(newSymNode(s, a.info))
var ti: TTabIter
var it = initTabIter(ti, s.tab)
while it != nil:
if it.kind in ExportableSymKinds+{skModule}:
strTableAdd(c.module.tab, it)
it = nextIter(ti, s.tab)
else:
while s != nil:
if s.kind in ExportableSymKinds+{skModule}:
x.add(newSymNode(s, a.info))
strTableAdd(c.module.tab, s)
s = nextOverloadIter(o, c, a)
result = n
proc shouldBeBracketExpr(n: PNode): bool =
assert n.kind in nkCallKinds
let a = n.sons[0]
if a.kind in nkCallKinds:
let b = a[0]
if b.kind in nkSymChoices:
for i in 0..<b.len:
if b[i].sym.magic == mArrGet:
let be = newNodeI(nkBracketExpr, n.info)
for i in 1..<a.len: be.add(a[i])
n.sons[0] = be
return true
proc setGenericParams(c: PContext, n: PNode) =
for i in 1 .. <n.len:
n[i].typ = semTypeNode(c, n[i], nil)
proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
result = n
if gCmd == cmdIdeTools: suggestExpr(c, n)
if nfSem in n.flags: return
case n.kind
of nkIdent, nkAccQuoted:
let checks = if efNoEvaluateGeneric in flags: {checkUndeclared}
else: {checkUndeclared, checkModule, checkAmbiguity}
var s = qualifiedLookUp(c, n, checks)
if c.inTypeClass == 0: semCaptureSym(s, c.p.owner)
result = semSym(c, n, s, flags)
if s.kind in {skProc, skMethod, skConverter, skIterator}:
#performProcvarCheck(c, n, s)
result = symChoice(c, n, s, scClosed)
if result.kind == nkSym:
markIndirect(c, result.sym)
# if isGenericRoutine(result.sym):
# localError(n.info, errInstantiateXExplicitly, s.name.s)
of nkSym:
# 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)
of nkEmpty, nkNone, nkCommentStmt:
discard
of nkNilLit:
if result.typ == nil: result.typ = getSysType(tyNil)
of nkIntLit:
if result.typ == nil: setIntLitType(result)
of nkInt8Lit:
if result.typ == nil: result.typ = getSysType(tyInt8)
of nkInt16Lit:
if result.typ == nil: result.typ = getSysType(tyInt16)
of nkInt32Lit:
if result.typ == nil: result.typ = getSysType(tyInt32)
of nkInt64Lit:
if result.typ == nil: result.typ = getSysType(tyInt64)
of nkUIntLit:
if result.typ == nil: result.typ = getSysType(tyUInt)
of nkUInt8Lit:
if result.typ == nil: result.typ = getSysType(tyUInt8)
of nkUInt16Lit:
if result.typ == nil: result.typ = getSysType(tyUInt16)
of nkUInt32Lit:
if result.typ == nil: result.typ = getSysType(tyUInt32)
of nkUInt64Lit:
if result.typ == nil: result.typ = getSysType(tyUInt64)
of nkFloatLit:
if result.typ == nil: result.typ = getFloatLitType(result)
of nkFloat32Lit:
if result.typ == nil: result.typ = getSysType(tyFloat32)
of nkFloat64Lit:
if result.typ == nil: result.typ = getSysType(tyFloat64)
of nkFloat128Lit:
if result.typ == nil: result.typ = getSysType(tyFloat128)
of nkStrLit..nkTripleStrLit:
if result.typ == nil: result.typ = getSysType(tyString)
of nkCharLit:
if result.typ == nil: result.typ = getSysType(tyChar)
of nkDotExpr:
result = semFieldAccess(c, n, flags)
if result.kind == nkDotCall:
result.kind = nkCall
result = semExpr(c, result, flags)
of nkBind:
message(n.info, warnDeprecated, "bind")
result = semExpr(c, n.sons[0], flags)
of nkTypeOfExpr, nkTupleTy, nkTupleClassTy, nkRefTy..nkEnumTy, nkStaticTy:
var typ = semTypeNode(c, n, nil).skipTypes({tyTypeDesc})
result.typ = makeTypeDesc(c, typ)
#result = symNodeFromType(c, typ, n.info)
of nkCall, nkInfix, nkPrefix, nkPostfix, nkCommand, nkCallStrLit:
# check if it is an expression macro:
checkMinSonsLen(n, 1)
let mode = if nfDotField in n.flags: {} else: {checkUndeclared}
var s = qualifiedLookUp(c, n.sons[0], mode)
if s != nil:
#if gCmd == cmdPretty and n.sons[0].kind == nkDotExpr:
# pretty.checkUse(n.sons[0].sons[1].info, s)
case s.kind
of skMacro:
if sfImmediate notin s.flags:
result = semDirectOp(c, n, flags)
else:
result = semMacroExpr(c, n, n, s, flags)
of skTemplate:
if sfImmediate notin s.flags:
result = semDirectOp(c, n, flags)
else:
result = semTemplateExpr(c, n, s, flags)
of skType:
# XXX think about this more (``set`` procs)
if n.len == 2:
result = semConv(c, n)
elif n.len == 1:
result = semObjConstr(c, n, flags)
elif contains(c.ambiguousSymbols, s.id):
errorUseQualifier(c, n.info, s)
elif s.magic == mNone: result = semDirectOp(c, n, flags)
else: result = semMagic(c, n, s, flags)
of skProc, skMethod, skConverter, skIterator:
if s.magic == mNone: result = semDirectOp(c, n, flags)
else: result = semMagic(c, n, s, flags)
else:
#liMessage(n.info, warnUser, renderTree(n));
result = semIndirectOp(c, n, flags)
elif (n[0].kind == nkBracketExpr or shouldBeBracketExpr(n)) and
isSymChoice(n[0][0]):
# indirectOp can deal with explicit instantiations; the fixes
# the 'newSeq[T](x)' bug
setGenericParams(c, n.sons[0])
result = semDirectOp(c, n, flags)
elif isSymChoice(n.sons[0]) or nfDotField in n.flags:
result = semDirectOp(c, n, flags)
else:
result = semIndirectOp(c, n, flags)
of nkWhen:
if efWantStmt in flags:
result = semWhen(c, n, true)
else:
result = semWhen(c, n, false)
if result == n:
# This is a "when nimvm" stmt.
result = semWhen(c, n, true)
else:
result = semExpr(c, result, flags)
of nkBracketExpr:
checkMinSonsLen(n, 1)
result = semArrayAccess(c, n, flags)
of nkCurlyExpr:
result = semExpr(c, buildOverloadedSubscripts(n, getIdent"{}"), flags)
of nkPragmaExpr:
# which pragmas are allowed for expressions? `likely`, `unlikely`
internalError(n.info, "semExpr() to implement") # XXX: to implement
of nkPar:
case checkPar(n)
of paNone: result = errorNode(c, n)
of paTuplePositions:
var tupexp = semTuplePositionsConstr(c, n, flags)
if isTupleType(tupexp):
# reinterpret as type
var typ = semTypeNode(c, n, nil).skipTypes({tyTypeDesc})
result.typ = makeTypeDesc(c, typ)
else:
result = tupexp
of paTupleFields: result = semTupleFieldsConstr(c, n, flags)
of paSingle: result = semExpr(c, n.sons[0], flags)
of nkCurly: result = semSetConstr(c, n)
of nkBracket: result = semArrayConstr(c, n, flags)
of nkObjConstr: result = semObjConstr(c, n, flags)
of nkLambda: result = semLambda(c, n, flags)
of nkDo: result = semDo(c, n, flags)
of nkDerefExpr: result = semDeref(c, n)
of nkAddr:
result = n
checkSonsLen(n, 1)
result = semAddr(c, n.sons[0])
of nkHiddenAddr, nkHiddenDeref:
checkSonsLen(n, 1)
n.sons[0] = semExpr(c, n.sons[0], flags)
of nkCast: result = semCast(c, n)
of nkIfExpr, nkIfStmt: result = semIf(c, n)
of nkHiddenStdConv, nkHiddenSubConv, nkConv, nkHiddenCallConv:
checkSonsLen(n, 2)
of nkStringToCString, nkCStringToString, nkObjDownConv, nkObjUpConv:
checkSonsLen(n, 1)
of nkChckRangeF, nkChckRange64, nkChckRange:
checkSonsLen(n, 3)
of nkCheckedFieldExpr:
checkMinSonsLen(n, 2)
of nkTableConstr:
result = semTableConstr(c, n)
of nkClosedSymChoice, nkOpenSymChoice:
# handling of sym choices is context dependent
# the node is left intact for now
discard
of nkStaticExpr:
result = semStaticExpr(c, n)
of nkAsgn: result = semAsgn(c, n)
of nkBlockStmt, nkBlockExpr: result = semBlock(c, n)
of nkStmtList, nkStmtListExpr: result = semStmtList(c, n, flags)
of nkRaiseStmt: result = semRaise(c, n)
of nkVarSection: result = semVarOrLet(c, n, skVar)
of nkLetSection: result = semVarOrLet(c, n, skLet)
of nkConstSection: result = semConst(c, n)
of nkTypeSection: result = semTypeSection(c, n)
of nkDiscardStmt: result = semDiscard(c, n)
of nkWhileStmt: result = semWhile(c, n)
of nkTryStmt: result = semTry(c, n)
of nkBreakStmt, nkContinueStmt: result = semBreakOrContinue(c, n)
of nkForStmt, nkParForStmt: result = semFor(c, n)
of nkCaseStmt: result = semCase(c, n)
of nkReturnStmt: result = semReturn(c, n)
of nkUsingStmt: result = semUsing(c, n)
of nkAsmStmt: result = semAsm(c, n)
of nkYieldStmt: result = semYield(c, n)
of nkPragma: pragma(c, c.p.owner, n, stmtPragmas)
of nkIteratorDef: result = semIterator(c, n)
of nkProcDef: result = semProc(c, n)
of nkMethodDef: result = semMethod(c, n)
of nkConverterDef: result = semConverterDef(c, n)
of nkMacroDef: result = semMacroDef(c, n)
of nkTemplateDef: result = semTemplateDef(c, n)
of nkImportStmt:
if not isTopLevel(c): localError(n.info, errXOnlyAtModuleScope, "import")
result = evalImport(c, n)
of nkImportExceptStmt:
if not isTopLevel(c): localError(n.info, errXOnlyAtModuleScope, "import")
result = evalImportExcept(c, n)
of nkFromStmt:
if not isTopLevel(c): localError(n.info, errXOnlyAtModuleScope, "from")
result = evalFrom(c, n)
of nkIncludeStmt:
#if not isTopLevel(c): localError(n.info, errXOnlyAtModuleScope, "include")
result = evalInclude(c, n)
of nkExportStmt, nkExportExceptStmt:
if not isTopLevel(c): localError(n.info, errXOnlyAtModuleScope, "export")
result = semExport(c, n)
of nkPragmaBlock:
result = semPragmaBlock(c, n)
of nkStaticStmt:
result = semStaticStmt(c, n)
of nkDefer:
n.sons[0] = semExpr(c, n.sons[0])
if not n.sons[0].typ.isEmptyType and not implicitlyDiscardable(n.sons[0]):
localError(n.info, errGenerated, "'defer' takes a 'void' expression")
#localError(n.info, errGenerated, "'defer' not allowed in this context")
else:
localError(n.info, errInvalidExpressionX,
renderTree(n, {renderNoComments}))
if result != nil: incl(result.flags, nfSem)