1 //===--- ExprConstant.cpp - Expression Constant Evaluator -----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the Expr constant evaluator.
12 //===----------------------------------------------------------------------===//
14 #include "clang/AST/APValue.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/CharUnits.h"
17 #include "clang/AST/RecordLayout.h"
18 #include "clang/AST/StmtVisitor.h"
19 #include "clang/AST/TypeLoc.h"
20 #include "clang/AST/ASTDiagnostic.h"
21 #include "clang/AST/Expr.h"
22 #include "clang/Basic/Builtins.h"
23 #include "clang/Basic/TargetInfo.h"
24 #include "llvm/ADT/SmallString.h"
27 using namespace clang;
31 /// EvalInfo - This is a private struct used by the evaluator to capture
32 /// information about a subexpression as it is folded. It retains information
33 /// about the AST context, but also maintains information about the folded
36 /// If an expression could be evaluated, it is still possible it is not a C
37 /// "integer constant expression" or constant expression. If not, this struct
38 /// captures information about how and why not.
40 /// One bit of information passed *into* the request for constant folding
41 /// indicates whether the subexpression is "evaluated" or not according to C
42 /// rules. For example, the RHS of (0 && foo()) is not evaluated. We can
43 /// evaluate the expression regardless of what the RHS is, but C only allows
44 /// certain things in certain situations.
47 const ASTContext &Ctx;
49 /// EvalResult - Contains information about the evaluation.
50 Expr::EvalResult &EvalResult;
52 typedef llvm::DenseMap<const OpaqueValueExpr*, APValue> MapTy;
54 const APValue *getOpaqueValue(const OpaqueValueExpr *e) const {
55 MapTy::const_iterator i = OpaqueValues.find(e);
56 if (i == OpaqueValues.end()) return 0;
60 EvalInfo(const ASTContext &ctx, Expr::EvalResult &evalresult)
61 : Ctx(ctx), EvalResult(evalresult) {}
63 const LangOptions &getLangOpts() { return Ctx.getLangOptions(); }
71 APSInt IntReal, IntImag;
72 APFloat FloatReal, FloatImag;
74 ComplexValue() : FloatReal(APFloat::Bogus), FloatImag(APFloat::Bogus) {}
76 void makeComplexFloat() { IsInt = false; }
77 bool isComplexFloat() const { return !IsInt; }
78 APFloat &getComplexFloatReal() { return FloatReal; }
79 APFloat &getComplexFloatImag() { return FloatImag; }
81 void makeComplexInt() { IsInt = true; }
82 bool isComplexInt() const { return IsInt; }
83 APSInt &getComplexIntReal() { return IntReal; }
84 APSInt &getComplexIntImag() { return IntImag; }
86 void moveInto(APValue &v) const {
88 v = APValue(FloatReal, FloatImag);
90 v = APValue(IntReal, IntImag);
92 void setFrom(const APValue &v) {
93 assert(v.isComplexFloat() || v.isComplexInt());
94 if (v.isComplexFloat()) {
96 FloatReal = v.getComplexFloatReal();
97 FloatImag = v.getComplexFloatImag();
100 IntReal = v.getComplexIntReal();
101 IntImag = v.getComplexIntImag();
110 const Expr *getLValueBase() { return Base; }
111 CharUnits getLValueOffset() { return Offset; }
113 void moveInto(APValue &v) const {
114 v = APValue(Base, Offset);
116 void setFrom(const APValue &v) {
117 assert(v.isLValue());
118 Base = v.getLValueBase();
119 Offset = v.getLValueOffset();
124 static bool Evaluate(EvalInfo &info, const Expr *E);
125 static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info);
126 static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info);
127 static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info);
128 static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result,
130 static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info);
131 static bool EvaluateComplex(const Expr *E, ComplexValue &Res, EvalInfo &Info);
133 //===----------------------------------------------------------------------===//
135 //===----------------------------------------------------------------------===//
137 static bool IsGlobalLValue(const Expr* E) {
140 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
141 if (isa<FunctionDecl>(DRE->getDecl()))
143 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
144 return VD->hasGlobalStorage();
148 if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(E))
149 return CLE->isFileScope();
154 static bool EvalPointerValueAsBool(LValue& Value, bool& Result) {
155 const Expr* Base = Value.Base;
157 // A null base expression indicates a null pointer. These are always
158 // evaluatable, and they are false unless the offset is zero.
160 Result = !Value.Offset.isZero();
164 // Require the base expression to be a global l-value.
165 if (!IsGlobalLValue(Base)) return false;
167 // We have a non-null base expression. These are generally known to
168 // be true, but if it'a decl-ref to a weak symbol it can be null at
172 const DeclRefExpr* DeclRef = dyn_cast<DeclRefExpr>(Base);
176 // If it's a weak symbol, it isn't constant-evaluable.
177 const ValueDecl* Decl = DeclRef->getDecl();
178 if (Decl->hasAttr<WeakAttr>() ||
179 Decl->hasAttr<WeakRefAttr>() ||
180 Decl->isWeakImported())
186 static bool HandleConversionToBool(const Expr* E, bool& Result,
188 if (E->getType()->isIntegralOrEnumerationType()) {
190 if (!EvaluateInteger(E, IntResult, Info))
192 Result = IntResult != 0;
194 } else if (E->getType()->isRealFloatingType()) {
195 APFloat FloatResult(0.0);
196 if (!EvaluateFloat(E, FloatResult, Info))
198 Result = !FloatResult.isZero();
200 } else if (E->getType()->hasPointerRepresentation()) {
201 LValue PointerResult;
202 if (!EvaluatePointer(E, PointerResult, Info))
204 return EvalPointerValueAsBool(PointerResult, Result);
205 } else if (E->getType()->isAnyComplexType()) {
206 ComplexValue ComplexResult;
207 if (!EvaluateComplex(E, ComplexResult, Info))
209 if (ComplexResult.isComplexFloat()) {
210 Result = !ComplexResult.getComplexFloatReal().isZero() ||
211 !ComplexResult.getComplexFloatImag().isZero();
213 Result = ComplexResult.getComplexIntReal().getBoolValue() ||
214 ComplexResult.getComplexIntImag().getBoolValue();
222 static APSInt HandleFloatToIntCast(QualType DestType, QualType SrcType,
223 APFloat &Value, const ASTContext &Ctx) {
224 unsigned DestWidth = Ctx.getIntWidth(DestType);
225 // Determine whether we are converting to unsigned or signed.
226 bool DestSigned = DestType->isSignedIntegerOrEnumerationType();
228 // FIXME: Warning for overflow.
229 APSInt Result(DestWidth, !DestSigned);
231 (void)Value.convertToInteger(Result, llvm::APFloat::rmTowardZero, &ignored);
235 static APFloat HandleFloatToFloatCast(QualType DestType, QualType SrcType,
236 APFloat &Value, const ASTContext &Ctx) {
238 APFloat Result = Value;
239 Result.convert(Ctx.getFloatTypeSemantics(DestType),
240 APFloat::rmNearestTiesToEven, &ignored);
244 static APSInt HandleIntToIntCast(QualType DestType, QualType SrcType,
245 APSInt &Value, const ASTContext &Ctx) {
246 unsigned DestWidth = Ctx.getIntWidth(DestType);
247 APSInt Result = Value;
248 // Figure out if this is a truncate, extend or noop cast.
249 // If the input is signed, do a sign extend, noop, or truncate.
250 Result = Result.extOrTrunc(DestWidth);
251 Result.setIsUnsigned(DestType->isUnsignedIntegerOrEnumerationType());
255 static APFloat HandleIntToFloatCast(QualType DestType, QualType SrcType,
256 APSInt &Value, const ASTContext &Ctx) {
258 APFloat Result(Ctx.getFloatTypeSemantics(DestType), 1);
259 Result.convertFromAPInt(Value, Value.isSigned(),
260 APFloat::rmNearestTiesToEven);
266 : public ConstStmtVisitor<HasSideEffect, bool> {
270 HasSideEffect(EvalInfo &info) : Info(info) {}
272 // Unhandled nodes conservatively default to having side effects.
273 bool VisitStmt(const Stmt *S) {
277 bool VisitParenExpr(const ParenExpr *E) { return Visit(E->getSubExpr()); }
278 bool VisitGenericSelectionExpr(const GenericSelectionExpr *E) {
279 return Visit(E->getResultExpr());
281 bool VisitDeclRefExpr(const DeclRefExpr *E) {
282 if (Info.Ctx.getCanonicalType(E->getType()).isVolatileQualified())
286 bool VisitObjCIvarRefExpr(const ObjCIvarRefExpr *E) {
287 if (Info.Ctx.getCanonicalType(E->getType()).isVolatileQualified())
291 bool VisitBlockDeclRefExpr (const BlockDeclRefExpr *E) {
292 if (Info.Ctx.getCanonicalType(E->getType()).isVolatileQualified())
297 // We don't want to evaluate BlockExprs multiple times, as they generate
299 bool VisitBlockExpr(const BlockExpr *E) { return true; }
300 bool VisitPredefinedExpr(const PredefinedExpr *E) { return false; }
301 bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E)
302 { return Visit(E->getInitializer()); }
303 bool VisitMemberExpr(const MemberExpr *E) { return Visit(E->getBase()); }
304 bool VisitIntegerLiteral(const IntegerLiteral *E) { return false; }
305 bool VisitFloatingLiteral(const FloatingLiteral *E) { return false; }
306 bool VisitStringLiteral(const StringLiteral *E) { return false; }
307 bool VisitCharacterLiteral(const CharacterLiteral *E) { return false; }
308 bool VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E)
310 bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E)
311 { return Visit(E->getLHS()) || Visit(E->getRHS()); }
312 bool VisitChooseExpr(const ChooseExpr *E)
313 { return Visit(E->getChosenSubExpr(Info.Ctx)); }
314 bool VisitCastExpr(const CastExpr *E) { return Visit(E->getSubExpr()); }
315 bool VisitBinAssign(const BinaryOperator *E) { return true; }
316 bool VisitCompoundAssignOperator(const BinaryOperator *E) { return true; }
317 bool VisitBinaryOperator(const BinaryOperator *E)
318 { return Visit(E->getLHS()) || Visit(E->getRHS()); }
319 bool VisitUnaryPreInc(const UnaryOperator *E) { return true; }
320 bool VisitUnaryPostInc(const UnaryOperator *E) { return true; }
321 bool VisitUnaryPreDec(const UnaryOperator *E) { return true; }
322 bool VisitUnaryPostDec(const UnaryOperator *E) { return true; }
323 bool VisitUnaryDeref(const UnaryOperator *E) {
324 if (Info.Ctx.getCanonicalType(E->getType()).isVolatileQualified())
326 return Visit(E->getSubExpr());
328 bool VisitUnaryOperator(const UnaryOperator *E) { return Visit(E->getSubExpr()); }
330 // Has side effects if any element does.
331 bool VisitInitListExpr(const InitListExpr *E) {
332 for (unsigned i = 0, e = E->getNumInits(); i != e; ++i)
333 if (Visit(E->getInit(i))) return true;
334 if (const Expr *filler = E->getArrayFiller())
335 return Visit(filler);
339 bool VisitSizeOfPackExpr(const SizeOfPackExpr *) { return false; }
342 class OpaqueValueEvaluation {
344 OpaqueValueExpr *opaqueValue;
347 OpaqueValueEvaluation(EvalInfo &info, OpaqueValueExpr *opaqueValue,
349 : info(info), opaqueValue(opaqueValue) {
351 // If evaluation fails, fail immediately.
352 if (!Evaluate(info, value)) {
353 this->opaqueValue = 0;
356 info.OpaqueValues[opaqueValue] = info.EvalResult.Val;
359 bool hasError() const { return opaqueValue == 0; }
361 ~OpaqueValueEvaluation() {
362 if (opaqueValue) info.OpaqueValues.erase(opaqueValue);
366 } // end anonymous namespace
368 //===----------------------------------------------------------------------===//
369 // Generic Evaluation
370 //===----------------------------------------------------------------------===//
373 template <class Derived, typename RetTy=void>
374 class ExprEvaluatorBase
375 : public ConstStmtVisitor<Derived, RetTy> {
377 RetTy DerivedSuccess(const APValue &V, const Expr *E) {
378 return static_cast<Derived*>(this)->Success(V, E);
380 RetTy DerivedError(const Expr *E) {
381 return static_cast<Derived*>(this)->Error(E);
383 RetTy DerivedValueInitialization(const Expr *E) {
384 return static_cast<Derived*>(this)->ValueInitialization(E);
389 typedef ConstStmtVisitor<Derived, RetTy> StmtVisitorTy;
390 typedef ExprEvaluatorBase ExprEvaluatorBaseTy;
392 RetTy ValueInitialization(const Expr *E) { return DerivedError(E); }
395 ExprEvaluatorBase(EvalInfo &Info) : Info(Info) {}
397 RetTy VisitStmt(const Stmt *) {
398 llvm_unreachable("Expression evaluator should not be called on stmts");
400 RetTy VisitExpr(const Expr *E) {
401 return DerivedError(E);
404 RetTy VisitParenExpr(const ParenExpr *E)
405 { return StmtVisitorTy::Visit(E->getSubExpr()); }
406 RetTy VisitUnaryExtension(const UnaryOperator *E)
407 { return StmtVisitorTy::Visit(E->getSubExpr()); }
408 RetTy VisitUnaryPlus(const UnaryOperator *E)
409 { return StmtVisitorTy::Visit(E->getSubExpr()); }
410 RetTy VisitChooseExpr(const ChooseExpr *E)
411 { return StmtVisitorTy::Visit(E->getChosenSubExpr(Info.Ctx)); }
412 RetTy VisitGenericSelectionExpr(const GenericSelectionExpr *E)
413 { return StmtVisitorTy::Visit(E->getResultExpr()); }
414 RetTy VisitSubstNonTypeTemplateParmExpr(const SubstNonTypeTemplateParmExpr *E)
415 { return StmtVisitorTy::Visit(E->getReplacement()); }
417 RetTy VisitBinaryConditionalOperator(const BinaryConditionalOperator *E) {
418 OpaqueValueEvaluation opaque(Info, E->getOpaqueValue(), E->getCommon());
419 if (opaque.hasError())
420 return DerivedError(E);
423 if (!HandleConversionToBool(E->getCond(), cond, Info))
424 return DerivedError(E);
426 return StmtVisitorTy::Visit(cond ? E->getTrueExpr() : E->getFalseExpr());
429 RetTy VisitConditionalOperator(const ConditionalOperator *E) {
431 if (!HandleConversionToBool(E->getCond(), BoolResult, Info))
432 return DerivedError(E);
434 Expr* EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr();
435 return StmtVisitorTy::Visit(EvalExpr);
438 RetTy VisitOpaqueValueExpr(const OpaqueValueExpr *E) {
439 const APValue *value = Info.getOpaqueValue(E);
441 return (E->getSourceExpr() ? StmtVisitorTy::Visit(E->getSourceExpr())
443 return DerivedSuccess(*value, E);
446 RetTy VisitInitListExpr(const InitListExpr *E) {
447 if (Info.getLangOpts().CPlusPlus0x) {
448 if (E->getNumInits() == 0)
449 return DerivedValueInitialization(E);
450 if (E->getNumInits() == 1)
451 return StmtVisitorTy::Visit(E->getInit(0));
453 return DerivedError(E);
455 RetTy VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) {
456 return DerivedValueInitialization(E);
458 RetTy VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) {
459 return DerivedValueInitialization(E);
466 //===----------------------------------------------------------------------===//
468 //===----------------------------------------------------------------------===//
470 class LValueExprEvaluator
471 : public ExprEvaluatorBase<LValueExprEvaluator, bool> {
473 const Decl *PrevDecl;
475 bool Success(const Expr *E) {
477 Result.Offset = CharUnits::Zero();
482 LValueExprEvaluator(EvalInfo &info, LValue &Result) :
483 ExprEvaluatorBaseTy(info), Result(Result), PrevDecl(0) {}
485 bool Success(const APValue &V, const Expr *E) {
489 bool Error(const Expr *E) {
493 bool VisitDeclRefExpr(const DeclRefExpr *E);
494 bool VisitPredefinedExpr(const PredefinedExpr *E) { return Success(E); }
495 bool VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
496 bool VisitMemberExpr(const MemberExpr *E);
497 bool VisitStringLiteral(const StringLiteral *E) { return Success(E); }
498 bool VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { return Success(E); }
499 bool VisitArraySubscriptExpr(const ArraySubscriptExpr *E);
500 bool VisitUnaryDeref(const UnaryOperator *E);
502 bool VisitCastExpr(const CastExpr *E) {
503 switch (E->getCastKind()) {
508 case CK_LValueBitCast:
509 return Visit(E->getSubExpr());
511 // FIXME: Support CK_DerivedToBase and friends.
515 // FIXME: Missing: __real__, __imag__
518 } // end anonymous namespace
520 static bool EvaluateLValue(const Expr* E, LValue& Result, EvalInfo &Info) {
521 return LValueExprEvaluator(Info, Result).Visit(E);
524 bool LValueExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
525 if (isa<FunctionDecl>(E->getDecl())) {
527 } else if (const VarDecl* VD = dyn_cast<VarDecl>(E->getDecl())) {
528 if (!VD->getType()->isReferenceType())
530 // Reference parameters can refer to anything even if they have an
531 // "initializer" in the form of a default argument.
532 if (!isa<ParmVarDecl>(VD)) {
533 // FIXME: Check whether VD might be overridden!
535 // Check for recursive initializers of references.
539 if (const Expr *Init = VD->getAnyInitializer())
544 return ExprEvaluatorBaseTy::VisitDeclRefExpr(E);
548 LValueExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
552 bool LValueExprEvaluator::VisitMemberExpr(const MemberExpr *E) {
555 if (!EvaluatePointer(E->getBase(), Result, Info))
557 Ty = E->getBase()->getType()->getAs<PointerType>()->getPointeeType();
559 if (!Visit(E->getBase()))
561 Ty = E->getBase()->getType();
564 const RecordDecl *RD = Ty->getAs<RecordType>()->getDecl();
565 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
567 const FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl());
568 if (!FD) // FIXME: deal with other kinds of member expressions
571 if (FD->getType()->isReferenceType())
574 unsigned i = FD->getFieldIndex();
575 Result.Offset += Info.Ctx.toCharUnitsFromBits(RL.getFieldOffset(i));
579 bool LValueExprEvaluator::VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
580 if (!EvaluatePointer(E->getBase(), Result, Info))
584 if (!EvaluateInteger(E->getIdx(), Index, Info))
587 CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(E->getType());
588 Result.Offset += Index.getSExtValue() * ElementSize;
592 bool LValueExprEvaluator::VisitUnaryDeref(const UnaryOperator *E) {
593 return EvaluatePointer(E->getSubExpr(), Result, Info);
596 //===----------------------------------------------------------------------===//
597 // Pointer Evaluation
598 //===----------------------------------------------------------------------===//
601 class PointerExprEvaluator
602 : public ExprEvaluatorBase<PointerExprEvaluator, bool> {
605 bool Success(const Expr *E) {
607 Result.Offset = CharUnits::Zero();
612 PointerExprEvaluator(EvalInfo &info, LValue &Result)
613 : ExprEvaluatorBaseTy(info), Result(Result) {}
615 bool Success(const APValue &V, const Expr *E) {
619 bool Error(const Stmt *S) {
622 bool ValueInitialization(const Expr *E) {
623 return Success((Expr*)0);
626 bool VisitBinaryOperator(const BinaryOperator *E);
627 bool VisitCastExpr(const CastExpr* E);
628 bool VisitUnaryAddrOf(const UnaryOperator *E);
629 bool VisitObjCStringLiteral(const ObjCStringLiteral *E)
630 { return Success(E); }
631 bool VisitAddrLabelExpr(const AddrLabelExpr *E)
632 { return Success(E); }
633 bool VisitCallExpr(const CallExpr *E);
634 bool VisitBlockExpr(const BlockExpr *E) {
635 if (!E->getBlockDecl()->hasCaptures())
639 bool VisitCXXNullPtrLiteralExpr(const CXXNullPtrLiteralExpr *E)
640 { return ValueInitialization(E); }
642 // FIXME: Missing: @protocol, @selector
644 } // end anonymous namespace
646 static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info) {
647 assert(E->getType()->hasPointerRepresentation());
648 return PointerExprEvaluator(Info, Result).Visit(E);
651 bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
652 if (E->getOpcode() != BO_Add &&
653 E->getOpcode() != BO_Sub)
656 const Expr *PExp = E->getLHS();
657 const Expr *IExp = E->getRHS();
658 if (IExp->getType()->isPointerType())
659 std::swap(PExp, IExp);
661 if (!EvaluatePointer(PExp, Result, Info))
665 if (!EvaluateInteger(IExp, Offset, Info))
667 int64_t AdditionalOffset
668 = Offset.isSigned() ? Offset.getSExtValue()
669 : static_cast<int64_t>(Offset.getZExtValue());
671 // Compute the new offset in the appropriate width.
673 QualType PointeeType =
674 PExp->getType()->getAs<PointerType>()->getPointeeType();
675 CharUnits SizeOfPointee;
677 // Explicitly handle GNU void* and function pointer arithmetic extensions.
678 if (PointeeType->isVoidType() || PointeeType->isFunctionType())
679 SizeOfPointee = CharUnits::One();
681 SizeOfPointee = Info.Ctx.getTypeSizeInChars(PointeeType);
683 if (E->getOpcode() == BO_Add)
684 Result.Offset += AdditionalOffset * SizeOfPointee;
686 Result.Offset -= AdditionalOffset * SizeOfPointee;
691 bool PointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) {
692 return EvaluateLValue(E->getSubExpr(), Result, Info);
696 bool PointerExprEvaluator::VisitCastExpr(const CastExpr* E) {
697 const Expr* SubExpr = E->getSubExpr();
699 switch (E->getCastKind()) {
705 case CK_CPointerToObjCPointerCast:
706 case CK_BlockPointerToObjCPointerCast:
707 case CK_AnyPointerToBlockPointerCast:
708 return Visit(SubExpr);
710 case CK_DerivedToBase:
711 case CK_UncheckedDerivedToBase: {
713 if (!EvaluatePointer(E->getSubExpr(), BaseLV, Info))
716 // Now figure out the necessary offset to add to the baseLV to get from
717 // the derived class to the base class.
718 CharUnits Offset = CharUnits::Zero();
720 QualType Ty = E->getSubExpr()->getType();
721 const CXXRecordDecl *DerivedDecl =
722 Ty->getAs<PointerType>()->getPointeeType()->getAsCXXRecordDecl();
724 for (CastExpr::path_const_iterator PathI = E->path_begin(),
725 PathE = E->path_end(); PathI != PathE; ++PathI) {
726 const CXXBaseSpecifier *Base = *PathI;
728 // FIXME: If the base is virtual, we'd need to determine the type of the
729 // most derived class and we don't support that right now.
730 if (Base->isVirtual())
733 const CXXRecordDecl *BaseDecl = Base->getType()->getAsCXXRecordDecl();
734 const ASTRecordLayout &Layout = Info.Ctx.getASTRecordLayout(DerivedDecl);
736 Offset += Layout.getBaseClassOffset(BaseDecl);
737 DerivedDecl = BaseDecl;
740 Result.Base = BaseLV.getLValueBase();
741 Result.Offset = BaseLV.getLValueOffset() + Offset;
745 case CK_NullToPointer: {
747 Result.Offset = CharUnits::Zero();
751 case CK_IntegralToPointer: {
753 if (!EvaluateIntegerOrLValue(SubExpr, Value, Info))
757 Value.getInt() = Value.getInt().extOrTrunc((unsigned)Info.Ctx.getTypeSize(E->getType()));
759 Result.Offset = CharUnits::fromQuantity(Value.getInt().getZExtValue());
762 // Cast is of an lvalue, no need to change value.
763 Result.Base = Value.getLValueBase();
764 Result.Offset = Value.getLValueOffset();
768 case CK_ArrayToPointerDecay:
769 case CK_FunctionToPointerDecay:
770 return EvaluateLValue(SubExpr, Result, Info);
776 bool PointerExprEvaluator::VisitCallExpr(const CallExpr *E) {
777 if (E->isBuiltinCall(Info.Ctx) ==
778 Builtin::BI__builtin___CFStringMakeConstantString ||
779 E->isBuiltinCall(Info.Ctx) ==
780 Builtin::BI__builtin___NSStringMakeConstantString)
783 return ExprEvaluatorBaseTy::VisitCallExpr(E);
786 //===----------------------------------------------------------------------===//
788 //===----------------------------------------------------------------------===//
791 class VectorExprEvaluator
792 : public ExprEvaluatorBase<VectorExprEvaluator, APValue> {
793 APValue GetZeroVector(QualType VecType);
796 VectorExprEvaluator(EvalInfo &info) : ExprEvaluatorBaseTy(info) {}
798 APValue Success(const APValue &V, const Expr *E) { return V; }
799 APValue Error(const Expr *E) { return APValue(); }
800 APValue ValueInitialization(const Expr *E)
801 { return GetZeroVector(E->getType()); }
803 APValue VisitUnaryReal(const UnaryOperator *E)
804 { return Visit(E->getSubExpr()); }
805 APValue VisitCastExpr(const CastExpr* E);
806 APValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
807 APValue VisitInitListExpr(const InitListExpr *E);
808 APValue VisitUnaryImag(const UnaryOperator *E);
809 // FIXME: Missing: unary -, unary ~, binary add/sub/mul/div,
810 // binary comparisons, binary and/or/xor,
811 // shufflevector, ExtVectorElementExpr
812 // (Note that these require implementing conversions
813 // between vector types.)
815 } // end anonymous namespace
817 static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) {
818 if (!E->getType()->isVectorType())
820 Result = VectorExprEvaluator(Info).Visit(E);
821 return !Result.isUninit();
824 APValue VectorExprEvaluator::VisitCastExpr(const CastExpr* E) {
825 const VectorType *VTy = E->getType()->getAs<VectorType>();
826 QualType EltTy = VTy->getElementType();
827 unsigned NElts = VTy->getNumElements();
828 unsigned EltWidth = Info.Ctx.getTypeSize(EltTy);
830 const Expr* SE = E->getSubExpr();
831 QualType SETy = SE->getType();
833 switch (E->getCastKind()) {
834 case CK_VectorSplat: {
835 APValue Result = APValue();
836 if (SETy->isIntegerType()) {
838 if (!EvaluateInteger(SE, IntResult, Info))
840 Result = APValue(IntResult);
841 } else if (SETy->isRealFloatingType()) {
843 if (!EvaluateFloat(SE, F, Info))
850 // Splat and create vector APValue.
851 SmallVector<APValue, 4> Elts(NElts, Result);
852 return APValue(&Elts[0], Elts.size());
855 if (SETy->isVectorType())
858 if (!SETy->isIntegerType())
862 if (!EvaluateInteger(SE, Init, Info))
865 assert((EltTy->isIntegerType() || EltTy->isRealFloatingType()) &&
866 "Vectors must be composed of ints or floats");
868 SmallVector<APValue, 4> Elts;
869 for (unsigned i = 0; i != NElts; ++i) {
870 APSInt Tmp = Init.extOrTrunc(EltWidth);
872 if (EltTy->isIntegerType())
873 Elts.push_back(APValue(Tmp));
875 Elts.push_back(APValue(APFloat(Tmp)));
879 return APValue(&Elts[0], Elts.size());
881 case CK_LValueToRValue:
890 VectorExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
891 return this->Visit(E->getInitializer());
895 VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) {
896 const VectorType *VT = E->getType()->getAs<VectorType>();
897 unsigned NumInits = E->getNumInits();
898 unsigned NumElements = VT->getNumElements();
900 QualType EltTy = VT->getElementType();
901 SmallVector<APValue, 4> Elements;
903 // If a vector is initialized with a single element, that value
904 // becomes every element of the vector, not just the first.
905 // This is the behavior described in the IBM AltiVec documentation.
908 // Handle the case where the vector is initialized by a another
909 // vector (OpenCL 6.1.6).
910 if (E->getInit(0)->getType()->isVectorType())
911 return this->Visit(const_cast<Expr*>(E->getInit(0)));
914 if (EltTy->isIntegerType()) {
915 llvm::APSInt sInt(32);
916 if (!EvaluateInteger(E->getInit(0), sInt, Info))
918 InitValue = APValue(sInt);
920 llvm::APFloat f(0.0);
921 if (!EvaluateFloat(E->getInit(0), f, Info))
923 InitValue = APValue(f);
925 for (unsigned i = 0; i < NumElements; i++) {
926 Elements.push_back(InitValue);
929 for (unsigned i = 0; i < NumElements; i++) {
930 if (EltTy->isIntegerType()) {
931 llvm::APSInt sInt(32);
933 if (!EvaluateInteger(E->getInit(i), sInt, Info))
936 sInt = Info.Ctx.MakeIntValue(0, EltTy);
938 Elements.push_back(APValue(sInt));
940 llvm::APFloat f(0.0);
942 if (!EvaluateFloat(E->getInit(i), f, Info))
945 f = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy));
947 Elements.push_back(APValue(f));
951 return APValue(&Elements[0], Elements.size());
955 VectorExprEvaluator::GetZeroVector(QualType T) {
956 const VectorType *VT = T->getAs<VectorType>();
957 QualType EltTy = VT->getElementType();
959 if (EltTy->isIntegerType())
960 ZeroElement = APValue(Info.Ctx.MakeIntValue(0, EltTy));
963 APValue(APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy)));
965 SmallVector<APValue, 4> Elements(VT->getNumElements(), ZeroElement);
966 return APValue(&Elements[0], Elements.size());
969 APValue VectorExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
970 if (!E->getSubExpr()->isEvaluatable(Info.Ctx))
971 Info.EvalResult.HasSideEffects = true;
972 return GetZeroVector(E->getType());
975 //===----------------------------------------------------------------------===//
976 // Integer Evaluation
977 //===----------------------------------------------------------------------===//
980 class IntExprEvaluator
981 : public ExprEvaluatorBase<IntExprEvaluator, bool> {
984 IntExprEvaluator(EvalInfo &info, APValue &result)
985 : ExprEvaluatorBaseTy(info), Result(result) {}
987 bool Success(const llvm::APSInt &SI, const Expr *E) {
988 assert(E->getType()->isIntegralOrEnumerationType() &&
989 "Invalid evaluation result.");
990 assert(SI.isSigned() == E->getType()->isSignedIntegerOrEnumerationType() &&
991 "Invalid evaluation result.");
992 assert(SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
993 "Invalid evaluation result.");
994 Result = APValue(SI);
998 bool Success(const llvm::APInt &I, const Expr *E) {
999 assert(E->getType()->isIntegralOrEnumerationType() &&
1000 "Invalid evaluation result.");
1001 assert(I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) &&
1002 "Invalid evaluation result.");
1003 Result = APValue(APSInt(I));
1004 Result.getInt().setIsUnsigned(
1005 E->getType()->isUnsignedIntegerOrEnumerationType());
1009 bool Success(uint64_t Value, const Expr *E) {
1010 assert(E->getType()->isIntegralOrEnumerationType() &&
1011 "Invalid evaluation result.");
1012 Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType()));
1016 bool Success(CharUnits Size, const Expr *E) {
1017 return Success(Size.getQuantity(), E);
1021 bool Error(SourceLocation L, diag::kind D, const Expr *E) {
1022 // Take the first error.
1023 if (Info.EvalResult.Diag == 0) {
1024 Info.EvalResult.DiagLoc = L;
1025 Info.EvalResult.Diag = D;
1026 Info.EvalResult.DiagExpr = E;
1031 bool Success(const APValue &V, const Expr *E) {
1032 return Success(V.getInt(), E);
1034 bool Error(const Expr *E) {
1035 return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
1038 bool ValueInitialization(const Expr *E) { return Success(0, E); }
1040 //===--------------------------------------------------------------------===//
1042 //===--------------------------------------------------------------------===//
1044 bool VisitIntegerLiteral(const IntegerLiteral *E) {
1045 return Success(E->getValue(), E);
1047 bool VisitCharacterLiteral(const CharacterLiteral *E) {
1048 return Success(E->getValue(), E);
1051 bool CheckReferencedDecl(const Expr *E, const Decl *D);
1052 bool VisitDeclRefExpr(const DeclRefExpr *E) {
1053 if (CheckReferencedDecl(E, E->getDecl()))
1056 return ExprEvaluatorBaseTy::VisitDeclRefExpr(E);
1058 bool VisitMemberExpr(const MemberExpr *E) {
1059 if (CheckReferencedDecl(E, E->getMemberDecl())) {
1060 // Conservatively assume a MemberExpr will have side-effects
1061 Info.EvalResult.HasSideEffects = true;
1065 return ExprEvaluatorBaseTy::VisitMemberExpr(E);
1068 bool VisitCallExpr(const CallExpr *E);
1069 bool VisitBinaryOperator(const BinaryOperator *E);
1070 bool VisitOffsetOfExpr(const OffsetOfExpr *E);
1071 bool VisitUnaryOperator(const UnaryOperator *E);
1073 bool VisitCastExpr(const CastExpr* E);
1074 bool VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *E);
1076 bool VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) {
1077 return Success(E->getValue(), E);
1080 // Note, GNU defines __null as an integer, not a pointer.
1081 bool VisitGNUNullExpr(const GNUNullExpr *E) {
1082 return ValueInitialization(E);
1085 bool VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) {
1086 return Success(E->getValue(), E);
1089 bool VisitBinaryTypeTraitExpr(const BinaryTypeTraitExpr *E) {
1090 return Success(E->getValue(), E);
1093 bool VisitArrayTypeTraitExpr(const ArrayTypeTraitExpr *E) {
1094 return Success(E->getValue(), E);
1097 bool VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
1098 return Success(E->getValue(), E);
1101 bool VisitUnaryReal(const UnaryOperator *E);
1102 bool VisitUnaryImag(const UnaryOperator *E);
1104 bool VisitCXXNoexceptExpr(const CXXNoexceptExpr *E);
1105 bool VisitSizeOfPackExpr(const SizeOfPackExpr *E);
1108 CharUnits GetAlignOfExpr(const Expr *E);
1109 CharUnits GetAlignOfType(QualType T);
1110 static QualType GetObjectType(const Expr *E);
1111 bool TryEvaluateBuiltinObjectSize(const CallExpr *E);
1112 // FIXME: Missing: array subscript of vector, member of vector
1114 } // end anonymous namespace
1116 static bool EvaluateIntegerOrLValue(const Expr* E, APValue &Result, EvalInfo &Info) {
1117 assert(E->getType()->isIntegralOrEnumerationType());
1118 return IntExprEvaluator(Info, Result).Visit(E);
1121 static bool EvaluateInteger(const Expr* E, APSInt &Result, EvalInfo &Info) {
1122 assert(E->getType()->isIntegralOrEnumerationType());
1125 if (!EvaluateIntegerOrLValue(E, Val, Info) || !Val.isInt())
1127 Result = Val.getInt();
1131 bool IntExprEvaluator::CheckReferencedDecl(const Expr* E, const Decl* D) {
1132 // Enums are integer constant exprs.
1133 if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) {
1134 // Check for signedness/width mismatches between E type and ECD value.
1135 bool SameSign = (ECD->getInitVal().isSigned()
1136 == E->getType()->isSignedIntegerOrEnumerationType());
1137 bool SameWidth = (ECD->getInitVal().getBitWidth()
1138 == Info.Ctx.getIntWidth(E->getType()));
1139 if (SameSign && SameWidth)
1140 return Success(ECD->getInitVal(), E);
1142 // Get rid of mismatch (otherwise Success assertions will fail)
1143 // by computing a new value matching the type of E.
1144 llvm::APSInt Val = ECD->getInitVal();
1146 Val.setIsSigned(!ECD->getInitVal().isSigned());
1148 Val = Val.extOrTrunc(Info.Ctx.getIntWidth(E->getType()));
1149 return Success(Val, E);
1153 // In C++, const, non-volatile integers initialized with ICEs are ICEs.
1154 // In C, they can also be folded, although they are not ICEs.
1155 if (Info.Ctx.getCanonicalType(E->getType()).getCVRQualifiers()
1156 == Qualifiers::Const) {
1158 if (isa<ParmVarDecl>(D))
1161 if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
1162 if (const Expr *Init = VD->getAnyInitializer()) {
1163 if (APValue *V = VD->getEvaluatedValue()) {
1165 return Success(V->getInt(), E);
1169 if (VD->isEvaluatingValue())
1172 VD->setEvaluatingValue();
1174 Expr::EvalResult EResult;
1175 if (Init->Evaluate(EResult, Info.Ctx) && !EResult.HasSideEffects &&
1176 EResult.Val.isInt()) {
1177 // Cache the evaluated value in the variable declaration.
1178 Result = EResult.Val;
1179 VD->setEvaluatedValue(Result);
1183 VD->setEvaluatedValue(APValue());
1188 // Otherwise, random variable references are not constants.
1192 /// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way
1194 static int EvaluateBuiltinClassifyType(const CallExpr *E) {
1195 // The following enum mimics the values returned by GCC.
1196 // FIXME: Does GCC differ between lvalue and rvalue references here?
1197 enum gcc_type_class {
1199 void_type_class, integer_type_class, char_type_class,
1200 enumeral_type_class, boolean_type_class,
1201 pointer_type_class, reference_type_class, offset_type_class,
1202 real_type_class, complex_type_class,
1203 function_type_class, method_type_class,
1204 record_type_class, union_type_class,
1205 array_type_class, string_type_class,
1209 // If no argument was supplied, default to "no_type_class". This isn't
1210 // ideal, however it is what gcc does.
1211 if (E->getNumArgs() == 0)
1212 return no_type_class;
1214 QualType ArgTy = E->getArg(0)->getType();
1215 if (ArgTy->isVoidType())
1216 return void_type_class;
1217 else if (ArgTy->isEnumeralType())
1218 return enumeral_type_class;
1219 else if (ArgTy->isBooleanType())
1220 return boolean_type_class;
1221 else if (ArgTy->isCharType())
1222 return string_type_class; // gcc doesn't appear to use char_type_class
1223 else if (ArgTy->isIntegerType())
1224 return integer_type_class;
1225 else if (ArgTy->isPointerType())
1226 return pointer_type_class;
1227 else if (ArgTy->isReferenceType())
1228 return reference_type_class;
1229 else if (ArgTy->isRealType())
1230 return real_type_class;
1231 else if (ArgTy->isComplexType())
1232 return complex_type_class;
1233 else if (ArgTy->isFunctionType())
1234 return function_type_class;
1235 else if (ArgTy->isStructureOrClassType())
1236 return record_type_class;
1237 else if (ArgTy->isUnionType())
1238 return union_type_class;
1239 else if (ArgTy->isArrayType())
1240 return array_type_class;
1241 else if (ArgTy->isUnionType())
1242 return union_type_class;
1243 else // FIXME: offset_type_class, method_type_class, & lang_type_class?
1244 llvm_unreachable("CallExpr::isBuiltinClassifyType(): unimplemented type");
1248 /// Retrieves the "underlying object type" of the given expression,
1249 /// as used by __builtin_object_size.
1250 QualType IntExprEvaluator::GetObjectType(const Expr *E) {
1251 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
1252 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
1253 return VD->getType();
1254 } else if (isa<CompoundLiteralExpr>(E)) {
1255 return E->getType();
1261 bool IntExprEvaluator::TryEvaluateBuiltinObjectSize(const CallExpr *E) {
1262 // TODO: Perhaps we should let LLVM lower this?
1264 if (!EvaluatePointer(E->getArg(0), Base, Info))
1267 // If we can prove the base is null, lower to zero now.
1268 const Expr *LVBase = Base.getLValueBase();
1269 if (!LVBase) return Success(0, E);
1271 QualType T = GetObjectType(LVBase);
1273 T->isIncompleteType() ||
1274 T->isFunctionType() ||
1275 T->isVariablyModifiedType() ||
1276 T->isDependentType())
1279 CharUnits Size = Info.Ctx.getTypeSizeInChars(T);
1280 CharUnits Offset = Base.getLValueOffset();
1282 if (!Offset.isNegative() && Offset <= Size)
1285 Size = CharUnits::Zero();
1286 return Success(Size, E);
1289 bool IntExprEvaluator::VisitCallExpr(const CallExpr *E) {
1290 switch (E->isBuiltinCall(Info.Ctx)) {
1292 return ExprEvaluatorBaseTy::VisitCallExpr(E);
1294 case Builtin::BI__builtin_object_size: {
1295 if (TryEvaluateBuiltinObjectSize(E))
1298 // If evaluating the argument has side-effects we can't determine
1299 // the size of the object and lower it to unknown now.
1300 if (E->getArg(0)->HasSideEffects(Info.Ctx)) {
1301 if (E->getArg(1)->EvaluateKnownConstInt(Info.Ctx).getZExtValue() <= 1)
1302 return Success(-1ULL, E);
1303 return Success(0, E);
1306 return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
1309 case Builtin::BI__builtin_classify_type:
1310 return Success(EvaluateBuiltinClassifyType(E), E);
1312 case Builtin::BI__builtin_constant_p:
1313 // __builtin_constant_p always has one operand: it returns true if that
1314 // operand can be folded, false otherwise.
1315 return Success(E->getArg(0)->isEvaluatable(Info.Ctx), E);
1317 case Builtin::BI__builtin_eh_return_data_regno: {
1318 int Operand = E->getArg(0)->EvaluateKnownConstInt(Info.Ctx).getZExtValue();
1319 Operand = Info.Ctx.getTargetInfo().getEHDataRegisterNumber(Operand);
1320 return Success(Operand, E);
1323 case Builtin::BI__builtin_expect:
1324 return Visit(E->getArg(0));
1326 case Builtin::BIstrlen:
1327 case Builtin::BI__builtin_strlen:
1328 // As an extension, we support strlen() and __builtin_strlen() as constant
1329 // expressions when the argument is a string literal.
1330 if (const StringLiteral *S
1331 = dyn_cast<StringLiteral>(E->getArg(0)->IgnoreParenImpCasts())) {
1332 // The string literal may have embedded null characters. Find the first
1333 // one and truncate there.
1334 StringRef Str = S->getString();
1335 StringRef::size_type Pos = Str.find(0);
1336 if (Pos != StringRef::npos)
1337 Str = Str.substr(0, Pos);
1339 return Success(Str.size(), E);
1342 return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E);
1346 bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
1347 if (E->getOpcode() == BO_Comma) {
1348 if (!Visit(E->getRHS()))
1351 // If we can't evaluate the LHS, it might have side effects;
1352 // conservatively mark it.
1353 if (!E->getLHS()->isEvaluatable(Info.Ctx))
1354 Info.EvalResult.HasSideEffects = true;
1359 if (E->isLogicalOp()) {
1360 // These need to be handled specially because the operands aren't
1361 // necessarily integral
1362 bool lhsResult, rhsResult;
1364 if (HandleConversionToBool(E->getLHS(), lhsResult, Info)) {
1365 // We were able to evaluate the LHS, see if we can get away with not
1366 // evaluating the RHS: 0 && X -> 0, 1 || X -> 1
1367 if (lhsResult == (E->getOpcode() == BO_LOr))
1368 return Success(lhsResult, E);
1370 if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) {
1371 if (E->getOpcode() == BO_LOr)
1372 return Success(lhsResult || rhsResult, E);
1374 return Success(lhsResult && rhsResult, E);
1377 if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) {
1378 // We can't evaluate the LHS; however, sometimes the result
1379 // is determined by the RHS: X && 0 -> 0, X || 1 -> 1.
1380 if (rhsResult == (E->getOpcode() == BO_LOr) ||
1381 !rhsResult == (E->getOpcode() == BO_LAnd)) {
1382 // Since we weren't able to evaluate the left hand side, it
1383 // must have had side effects.
1384 Info.EvalResult.HasSideEffects = true;
1386 return Success(rhsResult, E);
1394 QualType LHSTy = E->getLHS()->getType();
1395 QualType RHSTy = E->getRHS()->getType();
1397 if (LHSTy->isAnyComplexType()) {
1398 assert(RHSTy->isAnyComplexType() && "Invalid comparison");
1399 ComplexValue LHS, RHS;
1401 if (!EvaluateComplex(E->getLHS(), LHS, Info))
1404 if (!EvaluateComplex(E->getRHS(), RHS, Info))
1407 if (LHS.isComplexFloat()) {
1408 APFloat::cmpResult CR_r =
1409 LHS.getComplexFloatReal().compare(RHS.getComplexFloatReal());
1410 APFloat::cmpResult CR_i =
1411 LHS.getComplexFloatImag().compare(RHS.getComplexFloatImag());
1413 if (E->getOpcode() == BO_EQ)
1414 return Success((CR_r == APFloat::cmpEqual &&
1415 CR_i == APFloat::cmpEqual), E);
1417 assert(E->getOpcode() == BO_NE &&
1418 "Invalid complex comparison.");
1419 return Success(((CR_r == APFloat::cmpGreaterThan ||
1420 CR_r == APFloat::cmpLessThan ||
1421 CR_r == APFloat::cmpUnordered) ||
1422 (CR_i == APFloat::cmpGreaterThan ||
1423 CR_i == APFloat::cmpLessThan ||
1424 CR_i == APFloat::cmpUnordered)), E);
1427 if (E->getOpcode() == BO_EQ)
1428 return Success((LHS.getComplexIntReal() == RHS.getComplexIntReal() &&
1429 LHS.getComplexIntImag() == RHS.getComplexIntImag()), E);
1431 assert(E->getOpcode() == BO_NE &&
1432 "Invalid compex comparison.");
1433 return Success((LHS.getComplexIntReal() != RHS.getComplexIntReal() ||
1434 LHS.getComplexIntImag() != RHS.getComplexIntImag()), E);
1439 if (LHSTy->isRealFloatingType() &&
1440 RHSTy->isRealFloatingType()) {
1441 APFloat RHS(0.0), LHS(0.0);
1443 if (!EvaluateFloat(E->getRHS(), RHS, Info))
1446 if (!EvaluateFloat(E->getLHS(), LHS, Info))
1449 APFloat::cmpResult CR = LHS.compare(RHS);
1451 switch (E->getOpcode()) {
1453 llvm_unreachable("Invalid binary operator!");
1455 return Success(CR == APFloat::cmpLessThan, E);
1457 return Success(CR == APFloat::cmpGreaterThan, E);
1459 return Success(CR == APFloat::cmpLessThan || CR == APFloat::cmpEqual, E);
1461 return Success(CR == APFloat::cmpGreaterThan || CR == APFloat::cmpEqual,
1464 return Success(CR == APFloat::cmpEqual, E);
1466 return Success(CR == APFloat::cmpGreaterThan
1467 || CR == APFloat::cmpLessThan
1468 || CR == APFloat::cmpUnordered, E);
1472 if (LHSTy->isPointerType() && RHSTy->isPointerType()) {
1473 if (E->getOpcode() == BO_Sub || E->isEqualityOp()) {
1475 if (!EvaluatePointer(E->getLHS(), LHSValue, Info))
1479 if (!EvaluatePointer(E->getRHS(), RHSValue, Info))
1482 // Reject any bases from the normal codepath; we special-case comparisons
1484 if (LHSValue.getLValueBase()) {
1485 if (!E->isEqualityOp())
1487 if (RHSValue.getLValueBase() || !RHSValue.getLValueOffset().isZero())
1490 if (!EvalPointerValueAsBool(LHSValue, bres))
1492 return Success(bres ^ (E->getOpcode() == BO_EQ), E);
1493 } else if (RHSValue.getLValueBase()) {
1494 if (!E->isEqualityOp())
1496 if (LHSValue.getLValueBase() || !LHSValue.getLValueOffset().isZero())
1499 if (!EvalPointerValueAsBool(RHSValue, bres))
1501 return Success(bres ^ (E->getOpcode() == BO_EQ), E);
1504 if (E->getOpcode() == BO_Sub) {
1505 QualType Type = E->getLHS()->getType();
1506 QualType ElementType = Type->getAs<PointerType>()->getPointeeType();
1508 CharUnits ElementSize = CharUnits::One();
1509 if (!ElementType->isVoidType() && !ElementType->isFunctionType())
1510 ElementSize = Info.Ctx.getTypeSizeInChars(ElementType);
1512 CharUnits Diff = LHSValue.getLValueOffset() -
1513 RHSValue.getLValueOffset();
1514 return Success(Diff / ElementSize, E);
1517 if (E->getOpcode() == BO_EQ) {
1518 Result = LHSValue.getLValueOffset() == RHSValue.getLValueOffset();
1520 Result = LHSValue.getLValueOffset() != RHSValue.getLValueOffset();
1522 return Success(Result, E);
1525 if (!LHSTy->isIntegralOrEnumerationType() ||
1526 !RHSTy->isIntegralOrEnumerationType()) {
1527 // We can't continue from here for non-integral types, and they
1528 // could potentially confuse the following operations.
1532 // The LHS of a constant expr is always evaluated and needed.
1533 if (!Visit(E->getLHS()))
1534 return false; // error in subexpression.
1537 if (!EvaluateIntegerOrLValue(E->getRHS(), RHSVal, Info))
1540 // Handle cases like (unsigned long)&a + 4.
1541 if (E->isAdditiveOp() && Result.isLValue() && RHSVal.isInt()) {
1542 CharUnits Offset = Result.getLValueOffset();
1543 CharUnits AdditionalOffset = CharUnits::fromQuantity(
1544 RHSVal.getInt().getZExtValue());
1545 if (E->getOpcode() == BO_Add)
1546 Offset += AdditionalOffset;
1548 Offset -= AdditionalOffset;
1549 Result = APValue(Result.getLValueBase(), Offset);
1553 // Handle cases like 4 + (unsigned long)&a
1554 if (E->getOpcode() == BO_Add &&
1555 RHSVal.isLValue() && Result.isInt()) {
1556 CharUnits Offset = RHSVal.getLValueOffset();
1557 Offset += CharUnits::fromQuantity(Result.getInt().getZExtValue());
1558 Result = APValue(RHSVal.getLValueBase(), Offset);
1562 // All the following cases expect both operands to be an integer
1563 if (!Result.isInt() || !RHSVal.isInt())
1566 APSInt& RHS = RHSVal.getInt();
1568 switch (E->getOpcode()) {
1570 return Error(E->getOperatorLoc(), diag::note_invalid_subexpr_in_ice, E);
1571 case BO_Mul: return Success(Result.getInt() * RHS, E);
1572 case BO_Add: return Success(Result.getInt() + RHS, E);
1573 case BO_Sub: return Success(Result.getInt() - RHS, E);
1574 case BO_And: return Success(Result.getInt() & RHS, E);
1575 case BO_Xor: return Success(Result.getInt() ^ RHS, E);
1576 case BO_Or: return Success(Result.getInt() | RHS, E);
1579 return Error(E->getOperatorLoc(), diag::note_expr_divide_by_zero, E);
1580 return Success(Result.getInt() / RHS, E);
1583 return Error(E->getOperatorLoc(), diag::note_expr_divide_by_zero, E);
1584 return Success(Result.getInt() % RHS, E);
1586 // During constant-folding, a negative shift is an opposite shift.
1587 if (RHS.isSigned() && RHS.isNegative()) {
1594 = (unsigned) RHS.getLimitedValue(Result.getInt().getBitWidth()-1);
1595 return Success(Result.getInt() << SA, E);
1598 // During constant-folding, a negative shift is an opposite shift.
1599 if (RHS.isSigned() && RHS.isNegative()) {
1606 (unsigned) RHS.getLimitedValue(Result.getInt().getBitWidth()-1);
1607 return Success(Result.getInt() >> SA, E);
1610 case BO_LT: return Success(Result.getInt() < RHS, E);
1611 case BO_GT: return Success(Result.getInt() > RHS, E);
1612 case BO_LE: return Success(Result.getInt() <= RHS, E);
1613 case BO_GE: return Success(Result.getInt() >= RHS, E);
1614 case BO_EQ: return Success(Result.getInt() == RHS, E);
1615 case BO_NE: return Success(Result.getInt() != RHS, E);
1619 CharUnits IntExprEvaluator::GetAlignOfType(QualType T) {
1620 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
1621 // the result is the size of the referenced type."
1622 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the
1623 // result shall be the alignment of the referenced type."
1624 if (const ReferenceType *Ref = T->getAs<ReferenceType>())
1625 T = Ref->getPointeeType();
1627 // __alignof is defined to return the preferred alignment.
1628 return Info.Ctx.toCharUnitsFromBits(
1629 Info.Ctx.getPreferredTypeAlign(T.getTypePtr()));
1632 CharUnits IntExprEvaluator::GetAlignOfExpr(const Expr *E) {
1633 E = E->IgnoreParens();
1635 // alignof decl is always accepted, even if it doesn't make sense: we default
1636 // to 1 in those cases.
1637 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
1638 return Info.Ctx.getDeclAlign(DRE->getDecl(),
1639 /*RefAsPointee*/true);
1641 if (const MemberExpr *ME = dyn_cast<MemberExpr>(E))
1642 return Info.Ctx.getDeclAlign(ME->getMemberDecl(),
1643 /*RefAsPointee*/true);
1645 return GetAlignOfType(E->getType());
1649 /// VisitUnaryExprOrTypeTraitExpr - Evaluate a sizeof, alignof or vec_step with
1650 /// a result as the expression's type.
1651 bool IntExprEvaluator::VisitUnaryExprOrTypeTraitExpr(
1652 const UnaryExprOrTypeTraitExpr *E) {
1653 switch(E->getKind()) {
1654 case UETT_AlignOf: {
1655 if (E->isArgumentType())
1656 return Success(GetAlignOfType(E->getArgumentType()), E);
1658 return Success(GetAlignOfExpr(E->getArgumentExpr()), E);
1661 case UETT_VecStep: {
1662 QualType Ty = E->getTypeOfArgument();
1664 if (Ty->isVectorType()) {
1665 unsigned n = Ty->getAs<VectorType>()->getNumElements();
1667 // The vec_step built-in functions that take a 3-component
1668 // vector return 4. (OpenCL 1.1 spec 6.11.12)
1672 return Success(n, E);
1674 return Success(1, E);
1678 QualType SrcTy = E->getTypeOfArgument();
1679 // C++ [expr.sizeof]p2: "When applied to a reference or a reference type,
1680 // the result is the size of the referenced type."
1681 // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the
1682 // result shall be the alignment of the referenced type."
1683 if (const ReferenceType *Ref = SrcTy->getAs<ReferenceType>())
1684 SrcTy = Ref->getPointeeType();
1686 // sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc
1688 if (SrcTy->isVoidType() || SrcTy->isFunctionType())
1689 return Success(1, E);
1691 // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2.
1692 if (!SrcTy->isConstantSizeType())
1695 // Get information about the size.
1696 return Success(Info.Ctx.getTypeSizeInChars(SrcTy), E);
1700 llvm_unreachable("unknown expr/type trait");
1704 bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *OOE) {
1706 unsigned n = OOE->getNumComponents();
1709 QualType CurrentType = OOE->getTypeSourceInfo()->getType();
1710 for (unsigned i = 0; i != n; ++i) {
1711 OffsetOfExpr::OffsetOfNode ON = OOE->getComponent(i);
1712 switch (ON.getKind()) {
1713 case OffsetOfExpr::OffsetOfNode::Array: {
1714 const Expr *Idx = OOE->getIndexExpr(ON.getArrayExprIndex());
1716 if (!EvaluateInteger(Idx, IdxResult, Info))
1718 const ArrayType *AT = Info.Ctx.getAsArrayType(CurrentType);
1721 CurrentType = AT->getElementType();
1722 CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(CurrentType);
1723 Result += IdxResult.getSExtValue() * ElementSize;
1727 case OffsetOfExpr::OffsetOfNode::Field: {
1728 FieldDecl *MemberDecl = ON.getField();
1729 const RecordType *RT = CurrentType->getAs<RecordType>();
1732 RecordDecl *RD = RT->getDecl();
1733 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
1734 unsigned i = MemberDecl->getFieldIndex();
1735 assert(i < RL.getFieldCount() && "offsetof field in wrong type");
1736 Result += Info.Ctx.toCharUnitsFromBits(RL.getFieldOffset(i));
1737 CurrentType = MemberDecl->getType().getNonReferenceType();
1741 case OffsetOfExpr::OffsetOfNode::Identifier:
1742 llvm_unreachable("dependent __builtin_offsetof");
1745 case OffsetOfExpr::OffsetOfNode::Base: {
1746 CXXBaseSpecifier *BaseSpec = ON.getBase();
1747 if (BaseSpec->isVirtual())
1750 // Find the layout of the class whose base we are looking into.
1751 const RecordType *RT = CurrentType->getAs<RecordType>();
1754 RecordDecl *RD = RT->getDecl();
1755 const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD);
1757 // Find the base class itself.
1758 CurrentType = BaseSpec->getType();
1759 const RecordType *BaseRT = CurrentType->getAs<RecordType>();
1763 // Add the offset to the base.
1764 Result += RL.getBaseClassOffset(cast<CXXRecordDecl>(BaseRT->getDecl()));
1769 return Success(Result, OOE);
1772 bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
1773 if (E->getOpcode() == UO_LNot) {
1774 // LNot's operand isn't necessarily an integer, so we handle it specially.
1776 if (!HandleConversionToBool(E->getSubExpr(), bres, Info))
1778 return Success(!bres, E);
1781 // Only handle integral operations...
1782 if (!E->getSubExpr()->getType()->isIntegralOrEnumerationType())
1785 // Get the operand value into 'Result'.
1786 if (!Visit(E->getSubExpr()))
1789 switch (E->getOpcode()) {
1791 // Address, indirect, pre/post inc/dec, etc are not valid constant exprs.
1793 return Error(E->getOperatorLoc(), diag::note_invalid_subexpr_in_ice, E);
1795 // FIXME: Should extension allow i-c-e extension expressions in its scope?
1796 // If so, we could clear the diagnostic ID.
1799 // The result is always just the subexpr.
1802 if (!Result.isInt()) return false;
1803 return Success(-Result.getInt(), E);
1805 if (!Result.isInt()) return false;
1806 return Success(~Result.getInt(), E);
1810 /// HandleCast - This is used to evaluate implicit or explicit casts where the
1811 /// result type is integer.
1812 bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
1813 const Expr *SubExpr = E->getSubExpr();
1814 QualType DestType = E->getType();
1815 QualType SrcType = SubExpr->getType();
1817 switch (E->getCastKind()) {
1818 case CK_BaseToDerived:
1819 case CK_DerivedToBase:
1820 case CK_UncheckedDerivedToBase:
1823 case CK_ArrayToPointerDecay:
1824 case CK_FunctionToPointerDecay:
1825 case CK_NullToPointer:
1826 case CK_NullToMemberPointer:
1827 case CK_BaseToDerivedMemberPointer:
1828 case CK_DerivedToBaseMemberPointer:
1829 case CK_ConstructorConversion:
1830 case CK_IntegralToPointer:
1832 case CK_VectorSplat:
1833 case CK_IntegralToFloating:
1834 case CK_FloatingCast:
1835 case CK_CPointerToObjCPointerCast:
1836 case CK_BlockPointerToObjCPointerCast:
1837 case CK_AnyPointerToBlockPointerCast:
1838 case CK_ObjCObjectLValueCast:
1839 case CK_FloatingRealToComplex:
1840 case CK_FloatingComplexToReal:
1841 case CK_FloatingComplexCast:
1842 case CK_FloatingComplexToIntegralComplex:
1843 case CK_IntegralRealToComplex:
1844 case CK_IntegralComplexCast:
1845 case CK_IntegralComplexToFloatingComplex:
1846 llvm_unreachable("invalid cast kind for integral value");
1850 case CK_GetObjCProperty:
1851 case CK_LValueBitCast:
1852 case CK_UserDefinedConversion:
1853 case CK_ARCProduceObject:
1854 case CK_ARCConsumeObject:
1855 case CK_ARCReclaimReturnedObject:
1856 case CK_ARCExtendBlockObject:
1859 case CK_LValueToRValue:
1861 return Visit(E->getSubExpr());
1863 case CK_MemberPointerToBoolean:
1864 case CK_PointerToBoolean:
1865 case CK_IntegralToBoolean:
1866 case CK_FloatingToBoolean:
1867 case CK_FloatingComplexToBoolean:
1868 case CK_IntegralComplexToBoolean: {
1870 if (!HandleConversionToBool(SubExpr, BoolResult, Info))
1872 return Success(BoolResult, E);
1875 case CK_IntegralCast: {
1876 if (!Visit(SubExpr))
1879 if (!Result.isInt()) {
1880 // Only allow casts of lvalues if they are lossless.
1881 return Info.Ctx.getTypeSize(DestType) == Info.Ctx.getTypeSize(SrcType);
1884 return Success(HandleIntToIntCast(DestType, SrcType,
1885 Result.getInt(), Info.Ctx), E);
1888 case CK_PointerToIntegral: {
1890 if (!EvaluatePointer(SubExpr, LV, Info))
1893 if (LV.getLValueBase()) {
1894 // Only allow based lvalue casts if they are lossless.
1895 if (Info.Ctx.getTypeSize(DestType) != Info.Ctx.getTypeSize(SrcType))
1898 LV.moveInto(Result);
1902 APSInt AsInt = Info.Ctx.MakeIntValue(LV.getLValueOffset().getQuantity(),
1904 return Success(HandleIntToIntCast(DestType, SrcType, AsInt, Info.Ctx), E);
1907 case CK_IntegralComplexToReal: {
1909 if (!EvaluateComplex(SubExpr, C, Info))
1911 return Success(C.getComplexIntReal(), E);
1914 case CK_FloatingToIntegral: {
1916 if (!EvaluateFloat(SubExpr, F, Info))
1919 return Success(HandleFloatToIntCast(DestType, SrcType, F, Info.Ctx), E);
1923 llvm_unreachable("unknown cast resulting in integral value");
1927 bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
1928 if (E->getSubExpr()->getType()->isAnyComplexType()) {
1930 if (!EvaluateComplex(E->getSubExpr(), LV, Info) || !LV.isComplexInt())
1931 return Error(E->getExprLoc(), diag::note_invalid_subexpr_in_ice, E);
1932 return Success(LV.getComplexIntReal(), E);
1935 return Visit(E->getSubExpr());
1938 bool IntExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
1939 if (E->getSubExpr()->getType()->isComplexIntegerType()) {
1941 if (!EvaluateComplex(E->getSubExpr(), LV, Info) || !LV.isComplexInt())
1942 return Error(E->getExprLoc(), diag::note_invalid_subexpr_in_ice, E);
1943 return Success(LV.getComplexIntImag(), E);
1946 if (!E->getSubExpr()->isEvaluatable(Info.Ctx))
1947 Info.EvalResult.HasSideEffects = true;
1948 return Success(0, E);
1951 bool IntExprEvaluator::VisitSizeOfPackExpr(const SizeOfPackExpr *E) {
1952 return Success(E->getPackLength(), E);
1955 bool IntExprEvaluator::VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) {
1956 return Success(E->getValue(), E);
1959 //===----------------------------------------------------------------------===//
1961 //===----------------------------------------------------------------------===//
1964 class FloatExprEvaluator
1965 : public ExprEvaluatorBase<FloatExprEvaluator, bool> {
1968 FloatExprEvaluator(EvalInfo &info, APFloat &result)
1969 : ExprEvaluatorBaseTy(info), Result(result) {}
1971 bool Success(const APValue &V, const Expr *e) {
1972 Result = V.getFloat();
1975 bool Error(const Stmt *S) {
1979 bool ValueInitialization(const Expr *E) {
1980 Result = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(E->getType()));
1984 bool VisitCallExpr(const CallExpr *E);
1986 bool VisitUnaryOperator(const UnaryOperator *E);
1987 bool VisitBinaryOperator(const BinaryOperator *E);
1988 bool VisitFloatingLiteral(const FloatingLiteral *E);
1989 bool VisitCastExpr(const CastExpr *E);
1991 bool VisitUnaryReal(const UnaryOperator *E);
1992 bool VisitUnaryImag(const UnaryOperator *E);
1994 bool VisitDeclRefExpr(const DeclRefExpr *E);
1996 // FIXME: Missing: array subscript of vector, member of vector,
1997 // ImplicitValueInitExpr
1999 } // end anonymous namespace
2001 static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) {
2002 assert(E->getType()->isRealFloatingType());
2003 return FloatExprEvaluator(Info, Result).Visit(E);
2006 static bool TryEvaluateBuiltinNaN(const ASTContext &Context,
2010 llvm::APFloat &Result) {
2011 const StringLiteral *S = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts());
2012 if (!S) return false;
2014 const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(ResultTy);
2018 // Treat empty strings as if they were zero.
2019 if (S->getString().empty())
2020 fill = llvm::APInt(32, 0);
2021 else if (S->getString().getAsInteger(0, fill))
2025 Result = llvm::APFloat::getSNaN(Sem, false, &fill);
2027 Result = llvm::APFloat::getQNaN(Sem, false, &fill);
2031 bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) {
2032 switch (E->isBuiltinCall(Info.Ctx)) {
2034 return ExprEvaluatorBaseTy::VisitCallExpr(E);
2036 case Builtin::BI__builtin_huge_val:
2037 case Builtin::BI__builtin_huge_valf:
2038 case Builtin::BI__builtin_huge_vall:
2039 case Builtin::BI__builtin_inf:
2040 case Builtin::BI__builtin_inff:
2041 case Builtin::BI__builtin_infl: {
2042 const llvm::fltSemantics &Sem =
2043 Info.Ctx.getFloatTypeSemantics(E->getType());
2044 Result = llvm::APFloat::getInf(Sem);
2048 case Builtin::BI__builtin_nans:
2049 case Builtin::BI__builtin_nansf:
2050 case Builtin::BI__builtin_nansl:
2051 return TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
2054 case Builtin::BI__builtin_nan:
2055 case Builtin::BI__builtin_nanf:
2056 case Builtin::BI__builtin_nanl:
2057 // If this is __builtin_nan() turn this into a nan, otherwise we
2058 // can't constant fold it.
2059 return TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0),
2062 case Builtin::BI__builtin_fabs:
2063 case Builtin::BI__builtin_fabsf:
2064 case Builtin::BI__builtin_fabsl:
2065 if (!EvaluateFloat(E->getArg(0), Result, Info))
2068 if (Result.isNegative())
2069 Result.changeSign();
2072 case Builtin::BI__builtin_copysign:
2073 case Builtin::BI__builtin_copysignf:
2074 case Builtin::BI__builtin_copysignl: {
2076 if (!EvaluateFloat(E->getArg(0), Result, Info) ||
2077 !EvaluateFloat(E->getArg(1), RHS, Info))
2079 Result.copySign(RHS);
2085 bool FloatExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) {
2086 if (ExprEvaluatorBaseTy::VisitDeclRefExpr(E))
2089 const Decl *D = E->getDecl();
2090 if (!isa<VarDecl>(D) || isa<ParmVarDecl>(D)) return false;
2091 const VarDecl *VD = cast<VarDecl>(D);
2093 // Require the qualifiers to be const and not volatile.
2094 CanQualType T = Info.Ctx.getCanonicalType(E->getType());
2095 if (!T.isConstQualified() || T.isVolatileQualified())
2098 const Expr *Init = VD->getAnyInitializer();
2099 if (!Init) return false;
2101 if (APValue *V = VD->getEvaluatedValue()) {
2103 Result = V->getFloat();
2109 if (VD->isEvaluatingValue())
2112 VD->setEvaluatingValue();
2114 Expr::EvalResult InitResult;
2115 if (Init->Evaluate(InitResult, Info.Ctx) && !InitResult.HasSideEffects &&
2116 InitResult.Val.isFloat()) {
2117 // Cache the evaluated value in the variable declaration.
2118 Result = InitResult.Val.getFloat();
2119 VD->setEvaluatedValue(InitResult.Val);
2123 VD->setEvaluatedValue(APValue());
2127 bool FloatExprEvaluator::VisitUnaryReal(const UnaryOperator *E) {
2128 if (E->getSubExpr()->getType()->isAnyComplexType()) {
2130 if (!EvaluateComplex(E->getSubExpr(), CV, Info))
2132 Result = CV.FloatReal;
2136 return Visit(E->getSubExpr());
2139 bool FloatExprEvaluator::VisitUnaryImag(const UnaryOperator *E) {
2140 if (E->getSubExpr()->getType()->isAnyComplexType()) {
2142 if (!EvaluateComplex(E->getSubExpr(), CV, Info))
2144 Result = CV.FloatImag;
2148 if (!E->getSubExpr()->isEvaluatable(Info.Ctx))
2149 Info.EvalResult.HasSideEffects = true;
2150 const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(E->getType());
2151 Result = llvm::APFloat::getZero(Sem);
2155 bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
2156 if (E->getOpcode() == UO_Deref)
2159 if (!EvaluateFloat(E->getSubExpr(), Result, Info))
2162 switch (E->getOpcode()) {
2163 default: return false;
2167 Result.changeSign();
2172 bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
2173 if (E->getOpcode() == BO_Comma) {
2174 if (!EvaluateFloat(E->getRHS(), Result, Info))
2177 // If we can't evaluate the LHS, it might have side effects;
2178 // conservatively mark it.
2179 if (!E->getLHS()->isEvaluatable(Info.Ctx))
2180 Info.EvalResult.HasSideEffects = true;
2185 // We can't evaluate pointer-to-member operations.
2186 if (E->isPtrMemOp())
2189 // FIXME: Diagnostics? I really don't understand how the warnings
2190 // and errors are supposed to work.
2192 if (!EvaluateFloat(E->getLHS(), Result, Info))
2194 if (!EvaluateFloat(E->getRHS(), RHS, Info))
2197 switch (E->getOpcode()) {
2198 default: return false;
2200 Result.multiply(RHS, APFloat::rmNearestTiesToEven);
2203 Result.add(RHS, APFloat::rmNearestTiesToEven);
2206 Result.subtract(RHS, APFloat::rmNearestTiesToEven);
2209 Result.divide(RHS, APFloat::rmNearestTiesToEven);
2214 bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) {
2215 Result = E->getValue();
2219 bool FloatExprEvaluator::VisitCastExpr(const CastExpr *E) {
2220 const Expr* SubExpr = E->getSubExpr();
2222 switch (E->getCastKind()) {
2226 case CK_LValueToRValue:
2228 return Visit(SubExpr);
2230 case CK_IntegralToFloating: {
2232 if (!EvaluateInteger(SubExpr, IntResult, Info))
2234 Result = HandleIntToFloatCast(E->getType(), SubExpr->getType(),
2235 IntResult, Info.Ctx);
2239 case CK_FloatingCast: {
2240 if (!Visit(SubExpr))
2242 Result = HandleFloatToFloatCast(E->getType(), SubExpr->getType(),
2247 case CK_FloatingComplexToReal: {
2249 if (!EvaluateComplex(SubExpr, V, Info))
2251 Result = V.getComplexFloatReal();
2259 //===----------------------------------------------------------------------===//
2260 // Complex Evaluation (for float and integer)
2261 //===----------------------------------------------------------------------===//
2264 class ComplexExprEvaluator
2265 : public ExprEvaluatorBase<ComplexExprEvaluator, bool> {
2266 ComplexValue &Result;
2269 ComplexExprEvaluator(EvalInfo &info, ComplexValue &Result)
2270 : ExprEvaluatorBaseTy(info), Result(Result) {}
2272 bool Success(const APValue &V, const Expr *e) {
2276 bool Error(const Expr *E) {
2280 //===--------------------------------------------------------------------===//
2282 //===--------------------------------------------------------------------===//
2284 bool VisitImaginaryLiteral(const ImaginaryLiteral *E);
2286 bool VisitCastExpr(const CastExpr *E);
2288 bool VisitBinaryOperator(const BinaryOperator *E);
2289 bool VisitUnaryOperator(const UnaryOperator *E);
2290 // FIXME Missing: ImplicitValueInitExpr, InitListExpr
2292 } // end anonymous namespace
2294 static bool EvaluateComplex(const Expr *E, ComplexValue &Result,
2296 assert(E->getType()->isAnyComplexType());
2297 return ComplexExprEvaluator(Info, Result).Visit(E);
2300 bool ComplexExprEvaluator::VisitImaginaryLiteral(const ImaginaryLiteral *E) {
2301 const Expr* SubExpr = E->getSubExpr();
2303 if (SubExpr->getType()->isRealFloatingType()) {
2304 Result.makeComplexFloat();
2305 APFloat &Imag = Result.FloatImag;
2306 if (!EvaluateFloat(SubExpr, Imag, Info))
2309 Result.FloatReal = APFloat(Imag.getSemantics());
2312 assert(SubExpr->getType()->isIntegerType() &&
2313 "Unexpected imaginary literal.");
2315 Result.makeComplexInt();
2316 APSInt &Imag = Result.IntImag;
2317 if (!EvaluateInteger(SubExpr, Imag, Info))
2320 Result.IntReal = APSInt(Imag.getBitWidth(), !Imag.isSigned());
2325 bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
2327 switch (E->getCastKind()) {
2329 case CK_BaseToDerived:
2330 case CK_DerivedToBase:
2331 case CK_UncheckedDerivedToBase:
2334 case CK_ArrayToPointerDecay:
2335 case CK_FunctionToPointerDecay:
2336 case CK_NullToPointer:
2337 case CK_NullToMemberPointer:
2338 case CK_BaseToDerivedMemberPointer:
2339 case CK_DerivedToBaseMemberPointer:
2340 case CK_MemberPointerToBoolean:
2341 case CK_ConstructorConversion:
2342 case CK_IntegralToPointer:
2343 case CK_PointerToIntegral:
2344 case CK_PointerToBoolean:
2346 case CK_VectorSplat:
2347 case CK_IntegralCast:
2348 case CK_IntegralToBoolean:
2349 case CK_IntegralToFloating:
2350 case CK_FloatingToIntegral:
2351 case CK_FloatingToBoolean:
2352 case CK_FloatingCast:
2353 case CK_CPointerToObjCPointerCast:
2354 case CK_BlockPointerToObjCPointerCast:
2355 case CK_AnyPointerToBlockPointerCast:
2356 case CK_ObjCObjectLValueCast:
2357 case CK_FloatingComplexToReal:
2358 case CK_FloatingComplexToBoolean:
2359 case CK_IntegralComplexToReal:
2360 case CK_IntegralComplexToBoolean:
2361 case CK_ARCProduceObject:
2362 case CK_ARCConsumeObject:
2363 case CK_ARCReclaimReturnedObject:
2364 case CK_ARCExtendBlockObject:
2365 llvm_unreachable("invalid cast kind for complex value");
2367 case CK_LValueToRValue:
2369 return Visit(E->getSubExpr());
2372 case CK_GetObjCProperty:
2373 case CK_LValueBitCast:
2374 case CK_UserDefinedConversion:
2377 case CK_FloatingRealToComplex: {
2378 APFloat &Real = Result.FloatReal;
2379 if (!EvaluateFloat(E->getSubExpr(), Real, Info))
2382 Result.makeComplexFloat();
2383 Result.FloatImag = APFloat(Real.getSemantics());
2387 case CK_FloatingComplexCast: {
2388 if (!Visit(E->getSubExpr()))
2391 QualType To = E->getType()->getAs<ComplexType>()->getElementType();
2393 = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
2396 = HandleFloatToFloatCast(To, From, Result.FloatReal, Info.Ctx);
2398 = HandleFloatToFloatCast(To, From, Result.FloatImag, Info.Ctx);
2402 case CK_FloatingComplexToIntegralComplex: {
2403 if (!Visit(E->getSubExpr()))
2406 QualType To = E->getType()->getAs<ComplexType>()->getElementType();
2408 = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
2409 Result.makeComplexInt();
2410 Result.IntReal = HandleFloatToIntCast(To, From, Result.FloatReal, Info.Ctx);
2411 Result.IntImag = HandleFloatToIntCast(To, From, Result.FloatImag, Info.Ctx);
2415 case CK_IntegralRealToComplex: {
2416 APSInt &Real = Result.IntReal;
2417 if (!EvaluateInteger(E->getSubExpr(), Real, Info))
2420 Result.makeComplexInt();
2421 Result.IntImag = APSInt(Real.getBitWidth(), !Real.isSigned());
2425 case CK_IntegralComplexCast: {
2426 if (!Visit(E->getSubExpr()))
2429 QualType To = E->getType()->getAs<ComplexType>()->getElementType();
2431 = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
2433 Result.IntReal = HandleIntToIntCast(To, From, Result.IntReal, Info.Ctx);
2434 Result.IntImag = HandleIntToIntCast(To, From, Result.IntImag, Info.Ctx);
2438 case CK_IntegralComplexToFloatingComplex: {
2439 if (!Visit(E->getSubExpr()))
2442 QualType To = E->getType()->getAs<ComplexType>()->getElementType();
2444 = E->getSubExpr()->getType()->getAs<ComplexType>()->getElementType();
2445 Result.makeComplexFloat();
2446 Result.FloatReal = HandleIntToFloatCast(To, From, Result.IntReal, Info.Ctx);
2447 Result.FloatImag = HandleIntToFloatCast(To, From, Result.IntImag, Info.Ctx);
2452 llvm_unreachable("unknown cast resulting in complex value");
2456 bool ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) {
2457 if (E->getOpcode() == BO_Comma) {
2458 if (!Visit(E->getRHS()))
2461 // If we can't evaluate the LHS, it might have side effects;
2462 // conservatively mark it.
2463 if (!E->getLHS()->isEvaluatable(Info.Ctx))
2464 Info.EvalResult.HasSideEffects = true;
2468 if (!Visit(E->getLHS()))
2472 if (!EvaluateComplex(E->getRHS(), RHS, Info))
2475 assert(Result.isComplexFloat() == RHS.isComplexFloat() &&
2476 "Invalid operands to binary operator.");
2477 switch (E->getOpcode()) {
2478 default: return false;
2480 if (Result.isComplexFloat()) {
2481 Result.getComplexFloatReal().add(RHS.getComplexFloatReal(),
2482 APFloat::rmNearestTiesToEven);
2483 Result.getComplexFloatImag().add(RHS.getComplexFloatImag(),
2484 APFloat::rmNearestTiesToEven);
2486 Result.getComplexIntReal() += RHS.getComplexIntReal();
2487 Result.getComplexIntImag() += RHS.getComplexIntImag();
2491 if (Result.isComplexFloat()) {
2492 Result.getComplexFloatReal().subtract(RHS.getComplexFloatReal(),
2493 APFloat::rmNearestTiesToEven);
2494 Result.getComplexFloatImag().subtract(RHS.getComplexFloatImag(),
2495 APFloat::rmNearestTiesToEven);
2497 Result.getComplexIntReal() -= RHS.getComplexIntReal();
2498 Result.getComplexIntImag() -= RHS.getComplexIntImag();
2502 if (Result.isComplexFloat()) {
2503 ComplexValue LHS = Result;
2504 APFloat &LHS_r = LHS.getComplexFloatReal();
2505 APFloat &LHS_i = LHS.getComplexFloatImag();
2506 APFloat &RHS_r = RHS.getComplexFloatReal();
2507 APFloat &RHS_i = RHS.getComplexFloatImag();
2509 APFloat Tmp = LHS_r;
2510 Tmp.multiply(RHS_r, APFloat::rmNearestTiesToEven);
2511 Result.getComplexFloatReal() = Tmp;
2513 Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven);
2514 Result.getComplexFloatReal().subtract(Tmp, APFloat::rmNearestTiesToEven);
2517 Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven);
2518 Result.getComplexFloatImag() = Tmp;
2520 Tmp.multiply(RHS_r, APFloat::rmNearestTiesToEven);
2521 Result.getComplexFloatImag().add(Tmp, APFloat::rmNearestTiesToEven);
2523 ComplexValue LHS = Result;
2524 Result.getComplexIntReal() =
2525 (LHS.getComplexIntReal() * RHS.getComplexIntReal() -
2526 LHS.getComplexIntImag() * RHS.getComplexIntImag());
2527 Result.getComplexIntImag() =
2528 (LHS.getComplexIntReal() * RHS.getComplexIntImag() +
2529 LHS.getComplexIntImag() * RHS.getComplexIntReal());
2533 if (Result.isComplexFloat()) {
2534 ComplexValue LHS = Result;
2535 APFloat &LHS_r = LHS.getComplexFloatReal();
2536 APFloat &LHS_i = LHS.getComplexFloatImag();
2537 APFloat &RHS_r = RHS.getComplexFloatReal();
2538 APFloat &RHS_i = RHS.getComplexFloatImag();
2539 APFloat &Res_r = Result.getComplexFloatReal();
2540 APFloat &Res_i = Result.getComplexFloatImag();
2542 APFloat Den = RHS_r;
2543 Den.multiply(RHS_r, APFloat::rmNearestTiesToEven);
2544 APFloat Tmp = RHS_i;
2545 Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven);
2546 Den.add(Tmp, APFloat::rmNearestTiesToEven);
2549 Res_r.multiply(RHS_r, APFloat::rmNearestTiesToEven);
2551 Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven);
2552 Res_r.add(Tmp, APFloat::rmNearestTiesToEven);
2553 Res_r.divide(Den, APFloat::rmNearestTiesToEven);
2556 Res_i.multiply(RHS_r, APFloat::rmNearestTiesToEven);
2558 Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven);
2559 Res_i.subtract(Tmp, APFloat::rmNearestTiesToEven);
2560 Res_i.divide(Den, APFloat::rmNearestTiesToEven);
2562 if (RHS.getComplexIntReal() == 0 && RHS.getComplexIntImag() == 0) {
2563 // FIXME: what about diagnostics?
2566 ComplexValue LHS = Result;
2567 APSInt Den = RHS.getComplexIntReal() * RHS.getComplexIntReal() +
2568 RHS.getComplexIntImag() * RHS.getComplexIntImag();
2569 Result.getComplexIntReal() =
2570 (LHS.getComplexIntReal() * RHS.getComplexIntReal() +
2571 LHS.getComplexIntImag() * RHS.getComplexIntImag()) / Den;
2572 Result.getComplexIntImag() =
2573 (LHS.getComplexIntImag() * RHS.getComplexIntReal() -
2574 LHS.getComplexIntReal() * RHS.getComplexIntImag()) / Den;
2582 bool ComplexExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) {
2583 // Get the operand value into 'Result'.
2584 if (!Visit(E->getSubExpr()))
2587 switch (E->getOpcode()) {
2589 // FIXME: what about diagnostics?
2594 // The result is always just the subexpr.
2597 if (Result.isComplexFloat()) {
2598 Result.getComplexFloatReal().changeSign();
2599 Result.getComplexFloatImag().changeSign();
2602 Result.getComplexIntReal() = -Result.getComplexIntReal();
2603 Result.getComplexIntImag() = -Result.getComplexIntImag();
2607 if (Result.isComplexFloat())
2608 Result.getComplexFloatImag().changeSign();
2610 Result.getComplexIntImag() = -Result.getComplexIntImag();
2615 //===----------------------------------------------------------------------===//
2616 // Top level Expr::Evaluate method.
2617 //===----------------------------------------------------------------------===//
2619 static bool Evaluate(EvalInfo &Info, const Expr *E) {
2620 if (E->getType()->isVectorType()) {
2621 if (!EvaluateVector(E, Info.EvalResult.Val, Info))
2623 } else if (E->getType()->isIntegralOrEnumerationType()) {
2624 if (!IntExprEvaluator(Info, Info.EvalResult.Val).Visit(E))
2626 if (Info.EvalResult.Val.isLValue() &&
2627 !IsGlobalLValue(Info.EvalResult.Val.getLValueBase()))
2629 } else if (E->getType()->hasPointerRepresentation()) {
2631 if (!EvaluatePointer(E, LV, Info))
2633 if (!IsGlobalLValue(LV.Base))
2635 LV.moveInto(Info.EvalResult.Val);
2636 } else if (E->getType()->isRealFloatingType()) {
2637 llvm::APFloat F(0.0);
2638 if (!EvaluateFloat(E, F, Info))
2641 Info.EvalResult.Val = APValue(F);
2642 } else if (E->getType()->isAnyComplexType()) {
2644 if (!EvaluateComplex(E, C, Info))
2646 C.moveInto(Info.EvalResult.Val);
2653 /// Evaluate - Return true if this is a constant which we can fold using
2654 /// any crazy technique (that has nothing to do with language standards) that
2655 /// we want to. If this function returns true, it returns the folded constant
2657 bool Expr::Evaluate(EvalResult &Result, const ASTContext &Ctx) const {
2658 EvalInfo Info(Ctx, Result);
2659 return ::Evaluate(Info, this);
2662 bool Expr::EvaluateAsBooleanCondition(bool &Result,
2663 const ASTContext &Ctx) const {
2665 EvalInfo Info(Ctx, Scratch);
2667 return HandleConversionToBool(this, Result, Info);
2670 bool Expr::EvaluateAsInt(APSInt &Result, const ASTContext &Ctx) const {
2672 EvalInfo Info(Ctx, Scratch);
2674 return EvaluateInteger(this, Result, Info) && !Scratch.HasSideEffects;
2677 bool Expr::EvaluateAsLValue(EvalResult &Result, const ASTContext &Ctx) const {
2678 EvalInfo Info(Ctx, Result);
2681 if (EvaluateLValue(this, LV, Info) &&
2682 !Result.HasSideEffects &&
2683 IsGlobalLValue(LV.Base)) {
2684 LV.moveInto(Result.Val);
2690 bool Expr::EvaluateAsAnyLValue(EvalResult &Result,
2691 const ASTContext &Ctx) const {
2692 EvalInfo Info(Ctx, Result);
2695 if (EvaluateLValue(this, LV, Info)) {
2696 LV.moveInto(Result.Val);
2702 /// isEvaluatable - Call Evaluate to see if this expression can be constant
2703 /// folded, but discard the result.
2704 bool Expr::isEvaluatable(const ASTContext &Ctx) const {
2706 return Evaluate(Result, Ctx) && !Result.HasSideEffects;
2709 bool Expr::HasSideEffects(const ASTContext &Ctx) const {
2710 Expr::EvalResult Result;
2711 EvalInfo Info(Ctx, Result);
2712 return HasSideEffect(Info).Visit(this);
2715 APSInt Expr::EvaluateKnownConstInt(const ASTContext &Ctx) const {
2716 EvalResult EvalResult;
2717 bool Result = Evaluate(EvalResult, Ctx);
2719 assert(Result && "Could not evaluate expression");
2720 assert(EvalResult.Val.isInt() && "Expression did not evaluate to integer");
2722 return EvalResult.Val.getInt();
2725 bool Expr::EvalResult::isGlobalLValue() const {
2726 assert(Val.isLValue());
2727 return IsGlobalLValue(Val.getLValueBase());
2731 /// isIntegerConstantExpr - this recursive routine will test if an expression is
2732 /// an integer constant expression.
2734 /// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero,
2737 /// FIXME: Handle offsetof. Two things to do: Handle GCC's __builtin_offsetof
2738 /// to support gcc 4.0+ and handle the idiom GCC recognizes with a null pointer
2739 /// cast+dereference.
2741 // CheckICE - This function does the fundamental ICE checking: the returned
2742 // ICEDiag contains a Val of 0, 1, or 2, and a possibly null SourceLocation.
2743 // Note that to reduce code duplication, this helper does no evaluation
2744 // itself; the caller checks whether the expression is evaluatable, and
2745 // in the rare cases where CheckICE actually cares about the evaluated
2746 // value, it calls into Evalute.
2749 // 0: This expression is an ICE if it can be evaluated by Evaluate.
2750 // 1: This expression is not an ICE, but if it isn't evaluated, it's
2751 // a legal subexpression for an ICE. This return value is used to handle
2752 // the comma operator in C99 mode.
2753 // 2: This expression is not an ICE, and is not a legal subexpression for one.
2762 ICEDiag(unsigned v, SourceLocation l) : Val(v), Loc(l) {}
2763 ICEDiag() : Val(0) {}
2768 static ICEDiag NoDiag() { return ICEDiag(); }
2770 static ICEDiag CheckEvalInICE(const Expr* E, ASTContext &Ctx) {
2771 Expr::EvalResult EVResult;
2772 if (!E->Evaluate(EVResult, Ctx) || EVResult.HasSideEffects ||
2773 !EVResult.Val.isInt()) {
2774 return ICEDiag(2, E->getLocStart());
2779 static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
2780 assert(!E->isValueDependent() && "Should not see value dependent exprs!");
2781 if (!E->getType()->isIntegralOrEnumerationType()) {
2782 return ICEDiag(2, E->getLocStart());
2785 switch (E->getStmtClass()) {
2786 #define ABSTRACT_STMT(Node)
2787 #define STMT(Node, Base) case Expr::Node##Class:
2788 #define EXPR(Node, Base)
2789 #include "clang/AST/StmtNodes.inc"
2790 case Expr::PredefinedExprClass:
2791 case Expr::FloatingLiteralClass:
2792 case Expr::ImaginaryLiteralClass:
2793 case Expr::StringLiteralClass:
2794 case Expr::ArraySubscriptExprClass:
2795 case Expr::MemberExprClass:
2796 case Expr::CompoundAssignOperatorClass:
2797 case Expr::CompoundLiteralExprClass:
2798 case Expr::ExtVectorElementExprClass:
2799 case Expr::DesignatedInitExprClass:
2800 case Expr::ImplicitValueInitExprClass:
2801 case Expr::ParenListExprClass:
2802 case Expr::VAArgExprClass:
2803 case Expr::AddrLabelExprClass:
2804 case Expr::StmtExprClass:
2805 case Expr::CXXMemberCallExprClass:
2806 case Expr::CUDAKernelCallExprClass:
2807 case Expr::CXXDynamicCastExprClass:
2808 case Expr::CXXTypeidExprClass:
2809 case Expr::CXXUuidofExprClass:
2810 case Expr::CXXNullPtrLiteralExprClass:
2811 case Expr::CXXThisExprClass:
2812 case Expr::CXXThrowExprClass:
2813 case Expr::CXXNewExprClass:
2814 case Expr::CXXDeleteExprClass:
2815 case Expr::CXXPseudoDestructorExprClass:
2816 case Expr::UnresolvedLookupExprClass:
2817 case Expr::DependentScopeDeclRefExprClass:
2818 case Expr::CXXConstructExprClass:
2819 case Expr::CXXBindTemporaryExprClass:
2820 case Expr::ExprWithCleanupsClass:
2821 case Expr::CXXTemporaryObjectExprClass:
2822 case Expr::CXXUnresolvedConstructExprClass:
2823 case Expr::CXXDependentScopeMemberExprClass:
2824 case Expr::UnresolvedMemberExprClass:
2825 case Expr::ObjCStringLiteralClass:
2826 case Expr::ObjCEncodeExprClass:
2827 case Expr::ObjCMessageExprClass:
2828 case Expr::ObjCSelectorExprClass:
2829 case Expr::ObjCProtocolExprClass:
2830 case Expr::ObjCIvarRefExprClass:
2831 case Expr::ObjCPropertyRefExprClass:
2832 case Expr::ObjCIsaExprClass:
2833 case Expr::ShuffleVectorExprClass:
2834 case Expr::BlockExprClass:
2835 case Expr::BlockDeclRefExprClass:
2836 case Expr::NoStmtClass:
2837 case Expr::OpaqueValueExprClass:
2838 case Expr::PackExpansionExprClass:
2839 case Expr::SubstNonTypeTemplateParmPackExprClass:
2840 case Expr::AsTypeExprClass:
2841 case Expr::ObjCIndirectCopyRestoreExprClass:
2842 case Expr::MaterializeTemporaryExprClass:
2843 case Expr::AtomicExprClass:
2844 return ICEDiag(2, E->getLocStart());
2846 case Expr::InitListExprClass:
2847 if (Ctx.getLangOptions().CPlusPlus0x) {
2848 const InitListExpr *ILE = cast<InitListExpr>(E);
2849 if (ILE->getNumInits() == 0)
2851 if (ILE->getNumInits() == 1)
2852 return CheckICE(ILE->getInit(0), Ctx);
2853 // Fall through for more than 1 expression.
2855 return ICEDiag(2, E->getLocStart());
2857 case Expr::SizeOfPackExprClass:
2858 case Expr::GNUNullExprClass:
2859 // GCC considers the GNU __null value to be an integral constant expression.
2862 case Expr::SubstNonTypeTemplateParmExprClass:
2864 CheckICE(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(), Ctx);
2866 case Expr::ParenExprClass:
2867 return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx);
2868 case Expr::GenericSelectionExprClass:
2869 return CheckICE(cast<GenericSelectionExpr>(E)->getResultExpr(), Ctx);
2870 case Expr::IntegerLiteralClass:
2871 case Expr::CharacterLiteralClass:
2872 case Expr::CXXBoolLiteralExprClass:
2873 case Expr::CXXScalarValueInitExprClass:
2874 case Expr::UnaryTypeTraitExprClass:
2875 case Expr::BinaryTypeTraitExprClass:
2876 case Expr::ArrayTypeTraitExprClass:
2877 case Expr::ExpressionTraitExprClass:
2878 case Expr::CXXNoexceptExprClass:
2880 case Expr::CallExprClass:
2881 case Expr::CXXOperatorCallExprClass: {
2882 const CallExpr *CE = cast<CallExpr>(E);
2883 if (CE->isBuiltinCall(Ctx))
2884 return CheckEvalInICE(E, Ctx);
2885 return ICEDiag(2, E->getLocStart());
2887 case Expr::DeclRefExprClass:
2888 if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl()))
2890 if (Ctx.getLangOptions().CPlusPlus &&
2891 E->getType().getCVRQualifiers() == Qualifiers::Const) {
2892 const NamedDecl *D = cast<DeclRefExpr>(E)->getDecl();
2894 // Parameter variables are never constants. Without this check,
2895 // getAnyInitializer() can find a default argument, which leads
2897 if (isa<ParmVarDecl>(D))
2898 return ICEDiag(2, cast<DeclRefExpr>(E)->getLocation());
2901 // A variable of non-volatile const-qualified integral or enumeration
2902 // type initialized by an ICE can be used in ICEs.
2903 if (const VarDecl *Dcl = dyn_cast<VarDecl>(D)) {
2904 Qualifiers Quals = Ctx.getCanonicalType(Dcl->getType()).getQualifiers();
2905 if (Quals.hasVolatile() || !Quals.hasConst())
2906 return ICEDiag(2, cast<DeclRefExpr>(E)->getLocation());
2908 // Look for a declaration of this variable that has an initializer.
2909 const VarDecl *ID = 0;
2910 const Expr *Init = Dcl->getAnyInitializer(ID);
2912 if (ID->isInitKnownICE()) {
2913 // We have already checked whether this subexpression is an
2914 // integral constant expression.
2915 if (ID->isInitICE())
2918 return ICEDiag(2, cast<DeclRefExpr>(E)->getLocation());
2921 // It's an ICE whether or not the definition we found is
2922 // out-of-line. See DR 721 and the discussion in Clang PR
2923 // 6206 for details.
2925 if (Dcl->isCheckingICE()) {
2926 return ICEDiag(2, cast<DeclRefExpr>(E)->getLocation());
2929 Dcl->setCheckingICE();
2930 ICEDiag Result = CheckICE(Init, Ctx);
2931 // Cache the result of the ICE test.
2932 Dcl->setInitKnownICE(Result.Val == 0);
2937 return ICEDiag(2, E->getLocStart());
2938 case Expr::UnaryOperatorClass: {
2939 const UnaryOperator *Exp = cast<UnaryOperator>(E);
2940 switch (Exp->getOpcode()) {
2947 return ICEDiag(2, E->getLocStart());
2955 return CheckICE(Exp->getSubExpr(), Ctx);
2958 // OffsetOf falls through here.
2960 case Expr::OffsetOfExprClass: {
2961 // Note that per C99, offsetof must be an ICE. And AFAIK, using
2962 // Evaluate matches the proposed gcc behavior for cases like
2963 // "offsetof(struct s{int x[4];}, x[!.0])". This doesn't affect
2964 // compliance: we should warn earlier for offsetof expressions with
2965 // array subscripts that aren't ICEs, and if the array subscripts
2966 // are ICEs, the value of the offsetof must be an integer constant.
2967 return CheckEvalInICE(E, Ctx);
2969 case Expr::UnaryExprOrTypeTraitExprClass: {
2970 const UnaryExprOrTypeTraitExpr *Exp = cast<UnaryExprOrTypeTraitExpr>(E);
2971 if ((Exp->getKind() == UETT_SizeOf) &&
2972 Exp->getTypeOfArgument()->isVariableArrayType())
2973 return ICEDiag(2, E->getLocStart());
2976 case Expr::BinaryOperatorClass: {
2977 const BinaryOperator *Exp = cast<BinaryOperator>(E);
2978 switch (Exp->getOpcode()) {
2992 return ICEDiag(2, E->getLocStart());
3011 ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
3012 ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
3013 if (Exp->getOpcode() == BO_Div ||
3014 Exp->getOpcode() == BO_Rem) {
3015 // Evaluate gives an error for undefined Div/Rem, so make sure
3016 // we don't evaluate one.
3017 if (LHSResult.Val == 0 && RHSResult.Val == 0) {
3018 llvm::APSInt REval = Exp->getRHS()->EvaluateKnownConstInt(Ctx);
3020 return ICEDiag(1, E->getLocStart());
3021 if (REval.isSigned() && REval.isAllOnesValue()) {
3022 llvm::APSInt LEval = Exp->getLHS()->EvaluateKnownConstInt(Ctx);
3023 if (LEval.isMinSignedValue())
3024 return ICEDiag(1, E->getLocStart());
3028 if (Exp->getOpcode() == BO_Comma) {
3029 if (Ctx.getLangOptions().C99) {
3030 // C99 6.6p3 introduces a strange edge case: comma can be in an ICE
3031 // if it isn't evaluated.
3032 if (LHSResult.Val == 0 && RHSResult.Val == 0)
3033 return ICEDiag(1, E->getLocStart());
3035 // In both C89 and C++, commas in ICEs are illegal.
3036 return ICEDiag(2, E->getLocStart());
3039 if (LHSResult.Val >= RHSResult.Val)
3045 ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx);
3047 // C++0x [expr.const]p2:
3048 // [...] subexpressions of logical AND (5.14), logical OR
3049 // (5.15), and condi- tional (5.16) operations that are not
3050 // evaluated are not considered.
3051 if (Ctx.getLangOptions().CPlusPlus0x && LHSResult.Val == 0) {
3052 if (Exp->getOpcode() == BO_LAnd &&
3053 Exp->getLHS()->EvaluateKnownConstInt(Ctx) == 0)
3056 if (Exp->getOpcode() == BO_LOr &&
3057 Exp->getLHS()->EvaluateKnownConstInt(Ctx) != 0)
3061 ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx);
3062 if (LHSResult.Val == 0 && RHSResult.Val == 1) {
3063 // Rare case where the RHS has a comma "side-effect"; we need
3064 // to actually check the condition to see whether the side
3065 // with the comma is evaluated.
3066 if ((Exp->getOpcode() == BO_LAnd) !=
3067 (Exp->getLHS()->EvaluateKnownConstInt(Ctx) == 0))
3072 if (LHSResult.Val >= RHSResult.Val)
3078 case Expr::ImplicitCastExprClass:
3079 case Expr::CStyleCastExprClass:
3080 case Expr::CXXFunctionalCastExprClass:
3081 case Expr::CXXStaticCastExprClass:
3082 case Expr::CXXReinterpretCastExprClass:
3083 case Expr::CXXConstCastExprClass:
3084 case Expr::ObjCBridgedCastExprClass: {
3085 const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr();
3086 switch (cast<CastExpr>(E)->getCastKind()) {
3087 case CK_LValueToRValue:
3089 case CK_IntegralToBoolean:
3090 case CK_IntegralCast:
3091 return CheckICE(SubExpr, Ctx);
3093 if (isa<FloatingLiteral>(SubExpr->IgnoreParens()))
3095 return ICEDiag(2, E->getLocStart());
3098 case Expr::BinaryConditionalOperatorClass: {
3099 const BinaryConditionalOperator *Exp = cast<BinaryConditionalOperator>(E);
3100 ICEDiag CommonResult = CheckICE(Exp->getCommon(), Ctx);
3101 if (CommonResult.Val == 2) return CommonResult;
3102 ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
3103 if (FalseResult.Val == 2) return FalseResult;
3104 if (CommonResult.Val == 1) return CommonResult;
3105 if (FalseResult.Val == 1 &&
3106 Exp->getCommon()->EvaluateKnownConstInt(Ctx) == 0) return NoDiag();
3109 case Expr::ConditionalOperatorClass: {
3110 const ConditionalOperator *Exp = cast<ConditionalOperator>(E);
3111 // If the condition (ignoring parens) is a __builtin_constant_p call,
3112 // then only the true side is actually considered in an integer constant
3113 // expression, and it is fully evaluated. This is an important GNU
3114 // extension. See GCC PR38377 for discussion.
3115 if (const CallExpr *CallCE
3116 = dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts()))
3117 if (CallCE->isBuiltinCall(Ctx) == Builtin::BI__builtin_constant_p) {
3118 Expr::EvalResult EVResult;
3119 if (!E->Evaluate(EVResult, Ctx) || EVResult.HasSideEffects ||
3120 !EVResult.Val.isInt()) {
3121 return ICEDiag(2, E->getLocStart());
3125 ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx);
3126 if (CondResult.Val == 2)
3129 // C++0x [expr.const]p2:
3130 // subexpressions of [...] conditional (5.16) operations that
3131 // are not evaluated are not considered
3132 bool TrueBranch = Ctx.getLangOptions().CPlusPlus0x
3133 ? Exp->getCond()->EvaluateKnownConstInt(Ctx) != 0
3135 ICEDiag TrueResult = NoDiag();
3136 if (!Ctx.getLangOptions().CPlusPlus0x || TrueBranch)
3137 TrueResult = CheckICE(Exp->getTrueExpr(), Ctx);
3138 ICEDiag FalseResult = NoDiag();
3139 if (!Ctx.getLangOptions().CPlusPlus0x || !TrueBranch)
3140 FalseResult = CheckICE(Exp->getFalseExpr(), Ctx);
3142 if (TrueResult.Val == 2)
3144 if (FalseResult.Val == 2)
3146 if (CondResult.Val == 1)
3148 if (TrueResult.Val == 0 && FalseResult.Val == 0)
3150 // Rare case where the diagnostics depend on which side is evaluated
3151 // Note that if we get here, CondResult is 0, and at least one of
3152 // TrueResult and FalseResult is non-zero.
3153 if (Exp->getCond()->EvaluateKnownConstInt(Ctx) == 0) {
3158 case Expr::CXXDefaultArgExprClass:
3159 return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx);
3160 case Expr::ChooseExprClass: {
3161 return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(Ctx), Ctx);
3165 // Silence a GCC warning
3166 return ICEDiag(2, E->getLocStart());
3169 bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx,
3170 SourceLocation *Loc, bool isEvaluated) const {
3171 ICEDiag d = CheckICE(this, Ctx);
3173 if (Loc) *Loc = d.Loc;
3176 EvalResult EvalResult;
3177 if (!Evaluate(EvalResult, Ctx))
3178 llvm_unreachable("ICE cannot be evaluated!");
3179 assert(!EvalResult.HasSideEffects && "ICE with side effects!");
3180 assert(EvalResult.Val.isInt() && "ICE that isn't integer!");
3181 Result = EvalResult.Val.getInt();