#
#
# The Nimrod Compiler
# (c) Copyright 2012 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 restoreOldStyleType(n: PNode) =
# XXX: semExprWithType used to return the same type
# for nodes such as (100) or (int).
# This is inappropriate. The type of the first expression
# should be "int", while the type of the second one should
# be typedesc(int).
#
# This is strictly for backward compatibility until
# the transition to types as first-class values is complete.
if n.typ.kind == tyTypeDesc and n.typ.sonsLen == 1:
n.typ = n.typ.sons[0]
proc semTemplateExpr(c: PContext, n: PNode, s: PSym, semCheck = true): PNode =
markUsed(n, s)
pushInfoContext(n.info)
result = evalTemplate(n, s, getCurrOwner())
if semCheck: result = semAfterMacroCall(c, result, s)
popInfoContext()
proc semFieldAccess(c: PContext, n: PNode, flags: TExprFlags = {}): PNode
proc newDeref(n: PNode): PNode {.inline.} =
result = newNodeIT(nkHiddenDeref, n.info, n.typ.sons[0])
addSon(result, n)
proc semExprWithType(c: PContext, n: PNode, flags: TExprFlags = {}): PNode =
result = semExpr(c, n, flags)
if result.kind == nkEmpty:
# do not produce another redundant error message:
#raiseRecoverableError("")
result = errorNode(c, n)
if result.typ != nil:
if result.typ.kind == tyVar: result = newDeref(result)
else:
LocalError(n.info, errExprXHasNoType,
renderTree(result, {renderNoComments}))
result.typ = errorType(c)
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)
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)
result.typ = s.typ
result.info = n.info
proc performProcvarCheck(c: PContext, n: PNode, s: PSym) =
# XXX this not correct; it's valid to pass to templates and macros.
# We really need another post nkCallConv check for this. Or maybe do it
# in transform().
var smoduleId = getModule(s).id
if sfProcVar notin s.flags and s.typ.callConv == ccDefault and
smoduleId != c.module.id and smoduleId != c.friendModule.id:
LocalError(n.info, errXCannotBePassedToProcVar, s.name.s)
proc semSym(c: PContext, n: PNode, s: PSym, flags: TExprFlags): PNode =
case s.kind
of skConst:
markUsed(n, s)
case skipTypes(s.typ, abstractInst).kind
of tyNil, tyChar, tyInt..tyInt64, tyFloat..tyFloat128,
tyTuple, tySet, tyUInt..tyUInt64:
result = inlineConst(n, s)
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: result = semMacroExpr(c, n, n, s)
of skTemplate: result = semTemplateExpr(c, n, s)
of skVar, skLet, skResult, skParam, skForVar:
markUsed(n, s)
# if a proc accesses a global variable, it is not side effect free:
if sfGlobal in s.flags:
incl(c.p.owner.flags, sfSideEffect)
elif s.kind == skParam and s.typ.kind == tyExpr and s.typ.n != nil:
# XXX see the hack in sigmatch.nim ...
return s.typ.n
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:
if s.ast != nil: result = semExpr(c, s.ast)
else:
InternalError(n.info, "no default for")
result = emptyNode
of skType:
markUsed(n, s)
result = newSymNode(s, n.info)
result.typ = makeTypeDesc(c, s.typ)
else:
markUsed(n, s)
result = newSymNode(s, n.info)
type
TConvStatus = enum
convOK,
convNotNeedeed,
convNotLegal
proc checkConversionBetweenObjects(castDest, src: PType): TConvStatus =
return if inheritanceDiff(castDest, src) == high(int):
convNotLegal
else:
convOK
const
IntegralTypes = {tyBool, tyEnum, tyChar, tyInt..tyUInt64}
proc checkConvertible(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)
while (d != nil) and (d.Kind in {tyPtr, tyRef}) and (d.Kind == s.Kind):
d = base(d)
s = base(s)
if d == nil:
result = convNotLegal
elif d.Kind == tyObject and s.Kind == tyObject:
result = checkConversionBetweenObjects(d, s)
elif (skipTypes(castDest, abstractVarRange).Kind in IntegralTypes) and
(skipTypes(src, abstractVarRange).Kind in IntegralTypes):
# accept conversion between integral types
else:
# we use d, s here to speed up that operation a bit:
case cmpTypes(d, s)
of isNone, isGeneric:
if not compareTypes(castDest, src, dcEqIgnoreDistinct):
result = convNotLegal
else:
nil
proc isCastable(dst, src: PType): bool =
#const
# castableTypeKinds = {tyInt, tyPtr, tyRef, tyCstring, tyString,
# tySequence, tyPointer, tyNil, tyOpenArray,
# tyProc, tySet, tyEnum, tyBool, tyChar}
var ds, ss: biggestInt
# this is very unrestrictive; cast is allowed if castDest.size >= src.size
ds = computeSize(dst)
ss = computeSize(src)
if ds < 0:
result = false
elif ss < 0:
result = false
else:
result = (ds >= ss) or
(skipTypes(dst, abstractInst).kind in IntegralTypes) or
(skipTypes(src, abstractInst).kind in IntegralTypes)
proc isSymChoice(n: PNode): bool {.inline.} =
result = n.kind in nkSymChoices
proc semConv(c: PContext, n: PNode, s: PSym): PNode =
if sonsLen(n) != 2:
LocalError(n.info, errConvNeedsOneArg)
return n
result = newNodeI(nkConv, n.info)
result.typ = semTypeNode(c, n.sons[0], nil).skipTypes({tyGenericInst})
addSon(result, copyTree(n.sons[0]))
addSon(result, semExprWithType(c, n.sons[1]))
var op = result.sons[1]
if not isSymChoice(op):
let status = checkConvertible(result.typ, op.typ)
case status
of convOK: nil
of convNotNeedeed:
Message(n.info, hintConvFromXtoItselfNotNeeded, result.typ.typeToString)
of convNotLegal:
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(result.typ, it.typ)
if status == convOK:
markUsed(n, it.sym)
markIndirect(c, it.sym)
return it
localError(n.info, errUseQualifier, op.sons[0].sym.name.s)
proc semCast(c: PContext, n: PNode): PNode =
if optSafeCode in gGlobalOptions: localError(n.info, errCastNotInSafeMode)
#incl(c.p.owner.flags, sfSideEffect)
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])
restoreOldStyleType(n.sons[1])
var typ = skipTypes(n.sons[1].typ, abstractVarRange)
case typ.Kind
of tySequence, tyString, tyOpenArray, tyVarargs:
n.typ = getSysType(tyInt)
of tyArrayConstr, tyArray:
n.typ = n.sons[1].typ.sons[0] # indextype
of tyInt..tyInt64, tyChar, tyBool, tyEnum, tyUInt8, tyUInt16, tyUInt32:
n.typ = n.sons[1].typ
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])
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])
#restoreOldStyleType(n.sons[1])
#restoreOldStyleType(n.sons[2])
let a = skipTypes(n.sons[1].typ, typedescPtrs)
let b = skipTypes(n.sons[2].typ, typedescPtrs)
let x = skipTypes(n.sons[1].typ, abstractPtrs)
let y = skipTypes(n.sons[2].typ, abstractPtrs)
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 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])
if n[1].typ.kind != tyTypeDesc:
LocalError(n[0].info, errTypeExpected)
if n[2].kind notin {nkStrLit..nkTripleStrLit}:
let t2 = semTypeNode(c, n[2], nil)
n.sons[2] = newNodeIT(nkType, n[2].info, t2)
if n[1].typ.sonsLen == 0:
# this is a typedesc variable, leave for evals
return
else:
let t1 = n[1].typ.sons[0]
# BUGFIX: don't evaluate this too early: ``T is void``
if not containsGenericType(t1): result = evalIsOp(n)
proc semOpAux(c: PContext, n: PNode) =
let 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(considerAcc(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 SymtabGet(c.Tab, 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) =
case n.kind
of nkCurly, nkBracket:
for i in countup(0, sonsLen(n) - 1):
changeType(n.sons[i], elemType(newType))
of nkPar:
if newType.kind != tyTuple:
InternalError(n.info, "changeType: no tuple type for constructor")
elif newType.n == nil: nil
elif sonsLen(n) > 0 and n.sons[0].kind == nkExprColonExpr:
for i in countup(0, sonsLen(n) - 1):
var m = n.sons[i].sons[0]
if m.kind != nkSym:
internalError(m.info, "changeType(): invalid tuple constr")
return
var f = getSymFromList(newType.n, m.sym.name)
if f == nil:
internalError(m.info, "changeType(): invalid identifier")
return
changeType(n.sons[i].sons[1], f.typ)
else:
for i in countup(0, sonsLen(n) - 1):
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, newType.sons[i])
n.sons[i] = a
else: nil
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 x = n.sons[0]
var lastIndex: biggestInt = sonsLen(n) - 1
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): 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]
addSon(result, semExprWithType(c, x))
var typ = skipTypes(result.sons[0].typ, {tyGenericInst, tyVar, tyOrdinal})
# turn any concrete typedesc into the absract typedesc type
if typ.kind == tyTypeDesc: typ.sons = nil
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]
n.sons[i] = semExprWithType(c, x)
addSon(result, fitNode(c, typ, n.sons[i]))
inc(lastIndex)
addSonSkipIntLit(result.typ, typ)
result.typ.sons[0] = makeRangeType(c, 0, sonsLen(result) - 1, n.info)
proc fixAbstractType(c: PContext, n: PNode) =
# 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)
changeType(it.sons[1], s)
n.sons[i] = it.sons[1]
of nkBracket:
# an implicitely constructed array (passed to an open array):
n.sons[i] = semArrayConstr(c, it)
else:
nil
#if (it.typ == nil):
# InternalError(it.info, "fixAbstractType: " & renderTree(it))
proc skipObjConv(n: PNode): PNode =
case n.kind
of nkHiddenStdConv, nkHiddenSubConv, nkConv:
if skipTypes(n.sons[1].typ, abstractPtrs).kind in {tyTuple, tyObject}:
result = n.sons[1]
else:
result = n
of nkObjUpConv, nkObjDownConv: result = n.sons[0]
else: result = n
proc isAssignable(c: PContext, n: PNode): TAssignableResult =
result = parampatterns.isAssignable(c.p.owner, n)
proc newHiddenAddrTaken(c: PContext, n: PNode): PNode =
if n.kind == nkHiddenDeref:
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).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).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).kind != tyVar:
if n.sons[0].kind == nkSym: incl(n.sons[0].sym.flags, sfAddrTaken)
result = newHiddenAddrTaken(c, n)
else:
result = newHiddenAddrTaken(c, n) # BUGFIX!
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}
# 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!
for i in countup(1, sonsLen(n) - 1):
if i < sonsLen(t) and t.sons[i] != nil and
skipTypes(t.sons[i], abstractInst).kind == tyVar:
if isAssignable(c, n.sons[i]) notin {arLValue, arLocalLValue}:
LocalError(n.sons[i].info, errVarForOutParamNeeded)
return
for i in countup(1, sonsLen(n) - 1):
if i < sonsLen(t) and
skipTypes(t.sons[i], abstractInst).kind == tyVar:
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
# 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:
let a = getConstExpr(c.module, n.sons[i])
if a != nil: call.add(a)
else:
allConst = false
call.add(n.sons[i])
if allConst:
result = semfold.getConstExpr(c.module, call)
if result.isNil: result = n
else: return result
result.typ = semfold.getIntervalType(callee.magic, call)
# optimization pass: not necessary for correctness of the semantic pass
if {sfNoSideEffect, sfCompileTime} * callee.flags != {} and
{sfForward, sfImportc} * callee.flags == {}:
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 not typeAllowed(n.typ, skConst): 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)
if result.isNil:
LocalError(n.info, errCannotInterpretNodeX, renderTree(call))
else:
result = evalConstExpr(c.module, call)
if result.isNil: 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)
if result.isNil:
LocalError(n.info, errCannotInterpretNodeX, renderTree(n))
proc semOverloadedCallAnalyseEffects(c: PContext, n: PNode, nOrig: PNode,
flags: TExprFlags): PNode =
if {efInTypeOf, efWantIterator} * flags != {}:
# consider 'proc p(): seq[int]; for x in p()' here and
# 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("semDirectCallAnalyseEffects")
return
let callee = result.sons[0].sym
case callee.kind
of skMacro, skTemplate: nil
else:
if (callee.kind == skIterator) and (callee.id == c.p.owner.id):
LocalError(n.info, errRecursiveDependencyX, callee.name.s)
if sfNoSideEffect notin callee.flags:
if {sfImportc, sfSideEffect} * callee.flags != {}:
incl(c.p.owner.flags, sfSideEffect)
proc semDirectCallAnalyseEffects(c: PContext, n: PNode, nOrig: PNode,
flags: TExprFlags): PNode =
result = semOverloadedCallAnalyseEffects(c, n, nOrig, flags)
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)
n.sons[0] = semFieldAccess(c, n.sons[0])
if n.sons[0].kind == nkDotCall:
# it is a static call!
result = n.sons[0]
result.kind = nkCall
for i in countup(1, sonsLen(n) - 1): addSon(result, n.sons[i])
return semExpr(c, result, flags)
else:
n.sons[0] = semExpr(c, n.sons[0])
let nOrig = n.copyTree
semOpAux(c, n)
var t: PType = nil
if (n.sons[0].typ != nil): t = skipTypes(n.sons[0].typ, abstractInst)
if (t != nil) and (t.kind == tyProc):
# This is a proc variable, apply normal overload resolution
var m: TCandidate
initCandidate(m, t)
matches(c, n, nOrig, m)
if m.state != csMatch:
if c.inCompilesContext > 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
# we assume that a procedure that calls something indirectly
# has side-effects:
if tfNoSideEffect notin t.flags: incl(c.p.owner.flags, sfSideEffect)
elif (t != nil) and t.kind == tyTypeDesc:
let destType = t.skipTypes({tyTypeDesc, tyGenericInst})
result = semConv(c, n, symFromType(destType, n.info))
return
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:
n.sons[0] = prc
nOrig.sons[0] = prc
result = semOverloadedCallAnalyseEffects(c, n, nOrig, flags)
if result == nil:
if c.inCompilesContext > 0 or gErrorCounter == 0:
LocalError(n.info, errExprXCannotBeCalled,
renderTree(n, {renderNoComments}))
return errorNode(c, n)
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 semDirectOp(c: PContext, n: PNode, flags: TExprFlags): PNode =
# this seems to be a hotspot in the compiler!
let nOrig = n.copyTree
semOpAux(c, n)
result = semOverloadedCallAnalyseEffects(c, n, nOrig, flags)
if result == nil:
result = overloadedCallOpr(c, n)
if result == nil:
NotFoundError(c, n)
return errorNode(c, n)
let callee = result.sons[0].sym
case callee.kind
of skMacro: result = semMacroExpr(c, result, nOrig, callee)
of skTemplate: result = semTemplateExpr(c, result, callee)
else:
activate(c, n)
fixAbstractType(c, result)
analyseIfAddressTakenInCall(c, result)
if callee.magic != mNone:
result = magicsAfterOverloadResolution(c, result, flags)
result = evalAtCompileTime(c, result)
proc buildStringify(c: PContext, arg: PNode): PNode =
if arg.typ != nil and skipTypes(arg.typ, abstractInst).kind == tyString:
result = arg
else:
result = newNodeI(nkCall, arg.info)
addSon(result, newIdentNode(getIdent"$", arg.info))
addSon(result, arg)
proc semEcho(c: PContext, n: PNode): PNode =
# this really is a macro
checkMinSonsLen(n, 1)
for i in countup(1, sonsLen(n) - 1):
var arg = semExprWithType(c, n.sons[i])
n.sons[i] = semExpr(c, buildStringify(c, arg))
let t = n.sons[0].typ
if tfNoSideEffect notin t.flags: incl(c.p.owner.flags, sfSideEffect)
result = n
proc buildEchoStmt(c: PContext, n: PNode): PNode =
# we MUST not check 'n' for semantics again here!
result = newNodeI(nkCall, n.info)
var e = StrTableGet(magicsys.systemModule.Tab, getIdent"echo")
if e != nil:
addSon(result, newSymNode(e))
else:
LocalError(n.info, errSystemNeeds, "echo")
addSon(result, errorNode(c, n))
var arg = buildStringify(c, n)
# problem is: implicit '$' is not checked for semantics yet. So we give up
# and check 'arg' for semantics again:
addSon(result, semExpr(c, arg))
proc discardCheck(result: PNode) =
if result.typ != nil and result.typ.kind notin {tyStmt, tyEmpty}:
if result.kind == nkNilLit:
# XXX too much work and fixing would break bootstrapping:
#Message(n.info, warnNilStatement)
result.typ = nil
elif not ImplicitelyDiscardable(result) and result.typ.kind != tyError and
gCmd != cmdInteractive:
localError(result.info, errDiscardValue)
proc semExprNoType(c: PContext, n: PNode): PNode =
result = semExpr(c, n, {efWantStmt})
discardCheck(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 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
var s = newNodeI(nkCurly, r.info)
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 = newNodeI(nkCurly, n.info)
for j in countup(0, sonsLen(it) - 2): addSon(s, copyTree(it.sons[j]))
var inExpr = newNodeI(nkCall, n.info)
addSon(inExpr, newIdentNode(getIdent("in"), n.info))
addSon(inExpr, copyTree(r.sons[0]))
addSon(inExpr, s) #writeln(output, renderTree(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 = newNodeI(nkCall, n.info)
addSon(inExpr, newIdentNode(getIdent("in"), n.info))
addSon(inExpr, copyTree(r.sons[0]))
addSon(inExpr, s)
var notExpr = newNodeI(nkCall, n.info)
addSon(notExpr, newIdentNode(getIdent("not"), n.info))
addSon(notExpr, inExpr)
addSon(check, semExpr(c, 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
result = newNodeIT(nkHiddenDeref, n.info, t.sons[0])
addSon(result, a)
t = skipTypes(t.sons[0], {tyGenericInst})
proc builtinFieldAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
## returns nil if it's not a built-in field access
checkSonsLen(n, 2)
# early exit for this; see tests/compile/tbindoverload.nim:
if isSymChoice(n.sons[1]): return
var s = qualifiedLookup(c, n, {checkAmbiguity, checkUndeclared})
if s != nil:
return semSym(c, n, s, flags)
n.sons[0] = semExprWithType(c, n.sons[0], flags)
restoreOldStyleType(n.sons[0])
var i = considerAcc(n.sons[1])
var ty = n.sons[0].typ
var f: PSym = nil
result = nil
if isTypeExpr(n.sons[0]):
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, f)
return
of tyGenericInst:
assert ty.sons[0].kind == tyGenericBody
let tbody = ty.sons[0]
for s in countup(0, tbody.len-2):
let tParam = tbody.sons[s]
assert tParam.kind == tyGenericParam
if tParam.sym.name == i:
let foundTyp = makeTypeDesc(c, ty.sons[s + 1])
return newSymNode(copySym(tParam.sym).linkTo(foundTyp), n.info)
return
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
ty = skipTypes(ty, {tyGenericInst, tyVar, tyPtr, tyRef})
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?
n.sons[0] = makeDeref(n.sons[0])
n.sons[1] = newSymNode(f) # we now have the correct field
n.typ = f.typ
markUsed(n, f)
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:
n.sons[0] = makeDeref(n.sons[0])
n.sons[1] = newSymNode(f)
n.typ = f.typ
result = n
markUsed(n, f)
proc semFieldAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
# this is difficult, because the '.' is used in many different contexts
# in Nimrod. We first allow types in the semantic checking.
result = builtinFieldAccess(c, n, flags)
if result == nil:
if isSymChoice(n.sons[1]):
result = newNodeI(nkDotCall, n.info)
addSon(result, n.sons[1])
addSon(result, copyTree(n[0]))
else:
var i = considerAcc(n.sons[1])
var f = SymTabGet(c.tab, i)
# if f != nil and f.kind == skStub: loadStub(f)
# ``loadStub`` is not correct here as we don't care for ``f`` really
if f != nil:
# BUGFIX: do not check for (f.kind in {skProc, skMethod, skIterator}) here
# This special node kind is to merge with the call handler in `semExpr`.
result = newNodeI(nkDotCall, n.info)
addSon(result, newIdentNode(i, n[1].info))
addSon(result, copyTree(n[0]))
else:
if not ContainsOrIncl(c.UnknownIdents, i.id):
LocalError(n.Info, errUndeclaredFieldX, i.s)
result = errorNode(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.sons[0]
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:
var x = semDeref(c, n)
if x == nil: return nil
result = newNodeIT(nkDerefExpr, x.info, x.typ)
result.add(x[0])
return
checkMinSonsLen(n, 2)
n.sons[0] = semExprWithType(c, n.sons[0])
var arr = skipTypes(n.sons[0].typ, {tyGenericInst, tyVar, tyPtr, tyRef})
case arr.kind
of tyArray, tyOpenArray, tyVarargs, tyArrayConstr, tySequence, tyString,
tyCString:
checkSonsLen(n, 2)
n.sons[0] = makeDeref(n.sons[0])
for i in countup(1, sonsLen(n) - 1):
n.sons[i] = semExprWithType(c, n.sons[i], flags)
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 = symNodeFromType(c, semTypeNode(c, n, nil), n.info)
of tyTuple:
checkSonsLen(n, 2)
n.sons[0] = makeDeref(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: nil
proc semArrayAccess(c: PContext, n: PNode, flags: TExprFlags): PNode =
result = semSubscript(c, n, flags)
if result == nil:
# overloaded [] operator:
result = semExpr(c, buildOverloadedSubscripts(n, getIdent"[]"))
proc propertyWriteAccess(c: PContext, n, nOrig, a: PNode): PNode =
var id = considerAcc(a[1])
let 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])])
let orig = newNode(nkCall, n.info, sons = @[setterId, aOrig[0], nOrig[1]])
result = semDirectCallAnalyseEffects(c, result, orig, {})
if result != nil:
fixAbstractType(c, result)
analyseIfAddressTakenInCall(c, result)
else:
if not ContainsOrIncl(c.UnknownIdents, id.id):
LocalError(n.Info, errUndeclaredFieldX, id.s)
result = errorNode(c, n)
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: nil
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)
proc semAsgn(c: PContext, n: PNode): 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:
return propertyWriteAccess(c, n, nOrig, n[0])
of nkBracketExpr:
# a[i] = x
# --> `[]=`(a, i, x)
a = semSubscript(c, a, {efLValue})
if a == nil:
result = buildOverloadedSubscripts(n.sons[0], getIdent"[]=")
add(result, n[1])
return semExprNoType(c, result)
of nkCurlyExpr:
# a{i} = x --> `{}=`(a, i, x)
result = buildOverloadedSubscripts(n.sons[0], getIdent"{}=")
add(result, n[1])
return semExprNoType(c, result)
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:
var
rhs = semExprWithType(c, n.sons[1])
lhs = n.sons[0]
if lhs.kind == nkSym and lhs.sym.kind == skResult and
lhs.sym.typ.kind == tyGenericParam:
if matchTypeClass(lhs.typ, rhs.typ):
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)
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.tab)
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:
nil
elif result.kind == nkNilLit or ImplicitelyDiscardable(result):
# intended semantic: if it's 'discardable' and the context allows for it,
# discard it. This is bad for chaining but nicer for C wrappers.
# ambiguous :-(
result.typ = nil
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(result)
closeScope(c.tab)
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: nil
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 restype = c.p.owner.typ.sons[0]
if restype != nil:
n.sons[0] = fitNode(c, restype, n.sons[0])
if n.sons[0].typ == nil: InternalError(n.info, "semYield")
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 = SymtabLocalGet(c.tab, i)
else:
result = SymtabGet(c.Tab, 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):
if (n.sons[1].kind == nkIdent):
var ident = n.sons[1].ident
if m == c.module:
result = StrTableGet(c.tab.stack[ModuleTablePos], ident)
else:
result = StrTableGet(m.tab, ident)
else:
LocalError(n.sons[1].info, errIdentifierExpected, "")
of nkAccQuoted:
result = lookupForDefined(c, considerAcc(n), onlyCurrentScope)
of nkSym:
result = n.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 LookUpForDefined(c, n.sons[1], onlyCurrentScope) != nil:
result.intVal = 1
elif not onlyCurrentScope and (n.sons[1].kind == nkIdent) and
condsyms.isDefined(n.sons[1].ident):
result.intVal = 1
result.info = n.info
result.typ = getSysType(tyBool)
proc setMs(n: PNode, s: PSym): PNode =
result = n
n.sons[0] = newSymNode(s)
n.sons[0].info = n.info
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($magic), GetCurrOwner(), gCodegenLineInfo)
result.magic = magic
proc newAnonSym(kind: TSymKind, info: TLineInfo,
owner = getCurrOwner()): PSym =
result = newSym(kind, idAnon, owner, info)
result.flags = { sfGenSym }
proc semExpandToAst(c: PContext, n: PNode): PNode =
var macroCall = n[1]
var expandedSym = expectMacroOrTemplateCall(c, macroCall)
macroCall.sons[0] = newSymNode(expandedSym, macroCall.info)
markUsed(n, expandedSym)
for i in countup(1, macroCall.len-1):
macroCall.sons[i] = semExprWithType(c, macroCall[i], {})
# Preserve the magic symbol in order to be handled in evals.nim
InternalAssert n.sons[0].sym.magic == mExpandToAst
n.typ = getSysSym("PNimrodNode").typ # expandedSym.getReturnType
result = n
proc semExpandToAst(c: PContext, n: PNode, magicSym: PSym,
flags: TExprFlags = {}): PNode =
if sonsLen(n) == 2:
n.sons[0] = newSymNode(magicSym, n.info)
result = semExpandToAst(c, n)
else:
result = semDirectOp(c, n, flags)
proc processQuotations(n: var PNode, op: string,
quotes: var seq[PNode],
ids: var seq[PNode]) =
template returnQuote(q) =
quotes.add q
n = newIdentNode(getIdent($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]
if not n.isAtom:
for i in 0 .. <n.len:
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
internalAssert doBlk.kind == nkDo
processQuotations(doBlk.sons[bodyPos], op, quotes, ids)
doBlk.sons[namePos] = newAnonSym(skTemplate, n.info).newSymNode
if ids.len > 0:
doBlk[paramsPos].sons.setLen(2)
doBlk[paramsPos].sons[0] = getSysSym("stmt").newSymNode # return type
ids.add getSysSym("expr").newSymNode # params type
ids.add emptyNode # no default value
doBlk[paramsPos].sons[1] = 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
inc c.InCompilesContext
inc msgs.gSilence
# do not halt after first error:
msgs.gErrorMax = high(int)
# open a scope for temporary symbol inclusions:
let oldTos = c.tab.tos
openScope(c.tab)
let oldOwnerLen = len(gOwners)
let oldGenerics = c.generics
let oldContextLen = msgs.getInfoContextLen()
let oldInGenericContext = c.InGenericContext
let oldInUnrolledContext = c.InUnrolledContext
let oldInGenericInst = c.InGenericInst
let oldProcCon = c.p
c.generics = newGenericsCache()
try:
result = semExpr(c, n, flags)
if msgs.gErrorCounter != oldErrorCount: result = nil
except ERecoverableError:
nil
# undo symbol table changes (as far as it's possible):
c.generics = oldGenerics
c.InGenericContext = oldInGenericContext
c.InUnrolledContext = oldInUnrolledContext
c.InGenericInst = oldInGenericInst
c.p = oldProcCon
msgs.setInfoContextLen(oldContextLen)
setlen(gOwners, oldOwnerLen)
while c.tab.tos > oldTos: rawCloseScope(c.tab)
dec c.InCompilesContext
dec msgs.gSilence
msgs.gErrorCounter = oldErrorCount
msgs.gErrorMax = oldErrorMax
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 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 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 mEcho: result = semEcho(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)
else: result = semDirectOp(c, n, flags)
proc semIfExpr(c: PContext, n: PNode): PNode =
result = n
checkMinSonsLen(n, 2)
var typ: PType = nil
for i in countup(0, sonsLen(n) - 1):
var it = n.sons[i]
case it.kind
of nkElifExpr:
checkSonsLen(it, 2)
it.sons[0] = forceBool(c, semExprWithType(c, it.sons[0]))
it.sons[1] = semExprWithType(c, it.sons[1])
if typ == nil: typ = it.sons[1].typ
else: it.sons[1] = fitNode(c, typ, it.sons[1])
of nkElseExpr:
checkSonsLen(it, 1)
it.sons[0] = semExprWithType(c, it.sons[0])
if typ != nil: it.sons[0] = fitNode(c, typ, it.sons[0])
else: InternalError(it.info, "semIfExpr")
else: illFormedAst(n)
result.typ = typ
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:
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): 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.sons[i].kind != nkExprColonExpr) or
not (n.sons[i].sons[0].kind in {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])
var f = newSymS(skField, n.sons[i].sons[0], c)
f.typ = skipIntLit(n.sons[i].sons[1].typ)
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): 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])
addSonSkipIntLit(typ, n.sons[i].typ)
result.typ = typ
proc semStmtListExpr(c: PContext, n: PNode): PNode =
result = n
checkMinSonsLen(n, 1)
var length = sonsLen(n)
for i in countup(0, length - 2):
n.sons[i] = semStmt(c, n.sons[i])
if length > 0:
n.sons[length - 1] = semExprWithType(c, n.sons[length - 1])
n.typ = n.sons[length - 1].typ
proc semBlockExpr(c: PContext, n: PNode): PNode =
result = n
Inc(c.p.nestedBlockCounter)
checkSonsLen(n, 2)
openScope(c.tab) # BUGFIX: label is in the scope of block!
if n.sons[0].kind notin {nkEmpty, nkSym}:
# nkSym for gensym'ed labels:
addDecl(c, newSymS(skLabel, n.sons[0], c))
n.sons[1] = semStmtListExpr(c, n.sons[1])
n.typ = n.sons[1].typ
closeScope(c.tab)
Dec(c.p.nestedBlockCounter)
proc buildCall(n: PNode): PNode =
if n.kind == nkDotExpr and n.len == 2:
# x.y --> y(x)
result = newNodeI(nkCall, n.info, 2)
result.sons[0] = n.sons[1]
result.sons[1] = n.sons[0]
elif n.kind in nkCallKinds and n.sons[0].kind == nkDotExpr:
# x.y(a) -> y(x, a)
let a = n.sons[0]
result = newNodeI(nkCall, n.info, n.len+1)
result.sons[0] = a.sons[1]
result.sons[1] = a.sons[0]
for i in 1 .. <n.len: result.sons[i+1] = n.sons[i]
else:
result = n
proc semCaseExpr(c: PContext, caseStmt: PNode): PNode =
# The case expression is simply rewritten to a StmtListExpr:
# var res {.noInit, genSym.}: type(values)
#
# case E
# of X: res = value1
# of Y: res = value2
#
# res
var
info = caseStmt.info
resVar = newSym(skVar, idAnon, getCurrOwner(), info)
resNode = newSymNode(resVar, info)
resType: PType
resVar.flags = { sfGenSym, sfNoInit }
for i in countup(1, caseStmt.len - 1):
var cs = caseStmt[i]
case cs.kind
of nkOfBranch, nkElifBranch, nkElse:
# the value is always the last son regardless of the branch kind
cs.checkMinSonsLen 1
var value = cs{-1}
if value.kind == nkStmtList: value.kind = nkStmtListExpr
value = semExprWithType(c, value)
if resType == nil:
resType = value.typ
elif not sameType(resType, value.typ):
# XXX: semeType is a bit too harsh.
# work on finding a common base type.
# this will be useful for arrays/seq too:
# [ref DerivedA, ref DerivedB, ref Base]
typeMismatch(cs, resType, value.typ)
cs{-1} = newNode(nkAsgn, cs.info, @[resNode, value])
else:
IllFormedAst(caseStmt)
result = newNode(nkStmtListExpr, info, @[
newNode(nkVarSection, info, @[
newNode(nkIdentDefs, info, @[
resNode,
symNodeFromType(c, resType, info),
emptyNode])]),
caseStmt,
resNode])
result = semStmtListExpr(c, result)
proc fixImmediateParams(n: PNode): PNode =
# XXX: Temporary work-around until we carry out
# the planned overload resolution reforms
for i in 1 .. <n.len:
if n[i].kind == nkDo: n.sons[i] = n[i][bodyPos]
result = n
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, "invalid expr for 'export': " &
renderTree(a))
while s != nil:
if s.kind in ExportableSymKinds+{skModule}:
x.add(newSymNode(s, a.info))
s = nextOverloadIter(o, c, a)
if c.module.ast.isNil:
c.module.ast = newNodeI(nkStmtList, n.info)
assert c.module.ast.kind == nkStmtList
c.module.ast.add x
result = n
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:
var s = lookUp(c, n)
semCaptureSym(s, c.p.owner)
result = semSym(c, n, s, flags)
if s.kind in {skProc, skMethod, skIterator, skConverter}:
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, errInstantiateXExplicitely, 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:
nil
of nkNilLit:
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 = getSysType(tyFloat)
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:
var typ = semTypeNode(c, n, nil).skipTypes({tyTypeDesc})
result = symNodeFromType(c, typ, n.info)
of nkCall, nkInfix, nkPrefix, nkPostfix, nkCommand, nkCallStrLit:
# check if it is an expression macro:
checkMinSonsLen(n, 1)
var s = qualifiedLookup(c, n.sons[0], {checkUndeclared})
if s != nil:
case s.kind
of skMacro:
if sfImmediate notin s.flags:
result = semDirectOp(c, n, flags)
else:
var p = fixImmediateParams(n)
result = semMacroExpr(c, p, p, s)
of skTemplate:
if sfImmediate notin s.flags:
result = semDirectOp(c, n, flags)
else:
var p = fixImmediateParams(n)
result = semTemplateExpr(c, p, s)
of skType:
# XXX think about this more (``set`` procs)
if n.len == 2:
result = semConv(c, n, s)
elif Contains(c.AmbiguousSymbols, s.id):
LocalError(n.info, errUseQualifier, s.name.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 isSymChoice(n.sons[0]) or n[0].kind == nkBracketExpr and
isSymChoice(n[0][0]):
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)
result = semExpr(c, result, flags)
of nkBracketExpr:
checkMinSonsLen(n, 1)
var s = qualifiedLookup(c, n.sons[0], {checkUndeclared})
if s != nil and s.kind in {skProc, skMethod, skConverter, skIterator}:
# type parameters: partial generic specialization
n.sons[0] = semSymGenericInstantiation(c, n.sons[0], s)
result = explicitGenericInstantiation(c, n, s)
else:
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: result = semTuplePositionsConstr(c, n)
of paTupleFields: result = semTupleFieldsConstr(c, n)
of paSingle: result = semExpr(c, n.sons[0], flags)
of nkCurly: result = semSetConstr(c, n)
of nkBracket: result = semArrayConstr(c, n)
of nkLambdaKinds: result = semLambda(c, n, flags)
of nkDerefExpr: result = semDeref(c, n)
of nkAddr:
result = n
checkSonsLen(n, 1)
n.sons[0] = semExprWithType(c, n.sons[0])
if isAssignable(c, n.sons[0]) notin {arLValue, arLocalLValue}:
LocalError(n.info, errExprHasNoAddress)
n.typ = makePtrType(c, n.sons[0].typ)
of nkHiddenAddr, nkHiddenDeref:
checkSonsLen(n, 1)
n.sons[0] = semExpr(c, n.sons[0], flags)
of nkCast: result = semCast(c, n)
of nkIfExpr: result = semIfExpr(c, n)
of nkStmtListExpr: result = semStmtListExpr(c, n)
of nkBlockExpr: result = semBlockExpr(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
of nkStaticExpr:
result = semStaticExpr(c, n)
of nkAsgn: result = semAsgn(c, n)
of nkBlockStmt: result = semBlock(c, n)
of nkStmtList: result = semStmtList(c, n)
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 nkIfStmt: result = SemIf(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:
if efWantStmt in flags: result = semCase(c, n)
else: result = semCaseExpr(c, n)
of nkReturnStmt: result = semReturn(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)
else:
LocalError(n.info, errInvalidExpressionX,
renderTree(n, {renderNoComments}))
incl(result.flags, nfSem)