| //===--- ExprConstant.cpp - Expression Constant Evaluator -----------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the Expr constant evaluator. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/AST/APValue.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/CharUnits.h" |
| #include "clang/AST/RecordLayout.h" |
| #include "clang/AST/StmtVisitor.h" |
| #include "clang/AST/TypeLoc.h" |
| #include "clang/AST/ASTDiagnostic.h" |
| #include "clang/AST/Expr.h" |
| #include "clang/Basic/Builtins.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "llvm/ADT/SmallString.h" |
| #include <cstring> |
| |
| using namespace clang; |
| using llvm::APSInt; |
| using llvm::APFloat; |
| |
| /// EvalInfo - This is a private struct used by the evaluator to capture |
| /// information about a subexpression as it is folded. It retains information |
| /// about the AST context, but also maintains information about the folded |
| /// expression. |
| /// |
| /// If an expression could be evaluated, it is still possible it is not a C |
| /// "integer constant expression" or constant expression. If not, this struct |
| /// captures information about how and why not. |
| /// |
| /// One bit of information passed *into* the request for constant folding |
| /// indicates whether the subexpression is "evaluated" or not according to C |
| /// rules. For example, the RHS of (0 && foo()) is not evaluated. We can |
| /// evaluate the expression regardless of what the RHS is, but C only allows |
| /// certain things in certain situations. |
| struct EvalInfo { |
| ASTContext &Ctx; |
| |
| /// EvalResult - Contains information about the evaluation. |
| Expr::EvalResult &EvalResult; |
| |
| EvalInfo(ASTContext &ctx, Expr::EvalResult& evalresult) |
| : Ctx(ctx), EvalResult(evalresult) {} |
| }; |
| |
| namespace { |
| struct ComplexValue { |
| private: |
| bool IsInt; |
| |
| public: |
| APSInt IntReal, IntImag; |
| APFloat FloatReal, FloatImag; |
| |
| ComplexValue() : FloatReal(APFloat::Bogus), FloatImag(APFloat::Bogus) {} |
| |
| void makeComplexFloat() { IsInt = false; } |
| bool isComplexFloat() const { return !IsInt; } |
| APFloat &getComplexFloatReal() { return FloatReal; } |
| APFloat &getComplexFloatImag() { return FloatImag; } |
| |
| void makeComplexInt() { IsInt = true; } |
| bool isComplexInt() const { return IsInt; } |
| APSInt &getComplexIntReal() { return IntReal; } |
| APSInt &getComplexIntImag() { return IntImag; } |
| |
| void moveInto(APValue &v) { |
| if (isComplexFloat()) |
| v = APValue(FloatReal, FloatImag); |
| else |
| v = APValue(IntReal, IntImag); |
| } |
| }; |
| |
| struct LValue { |
| Expr *Base; |
| CharUnits Offset; |
| |
| Expr *getLValueBase() { return Base; } |
| CharUnits getLValueOffset() { return Offset; } |
| |
| void moveInto(APValue &v) { |
| v = APValue(Base, Offset); |
| } |
| }; |
| } |
| |
| static bool EvaluateLValue(const Expr *E, LValue &Result, EvalInfo &Info); |
| static bool EvaluatePointer(const Expr *E, LValue &Result, EvalInfo &Info); |
| static bool EvaluateInteger(const Expr *E, APSInt &Result, EvalInfo &Info); |
| static bool EvaluateIntegerOrLValue(const Expr *E, APValue &Result, |
| EvalInfo &Info); |
| static bool EvaluateFloat(const Expr *E, APFloat &Result, EvalInfo &Info); |
| static bool EvaluateComplex(const Expr *E, ComplexValue &Res, EvalInfo &Info); |
| |
| //===----------------------------------------------------------------------===// |
| // Misc utilities |
| //===----------------------------------------------------------------------===// |
| |
| static bool IsGlobalLValue(const Expr* E) { |
| if (!E) return true; |
| |
| if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) { |
| if (isa<FunctionDecl>(DRE->getDecl())) |
| return true; |
| if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) |
| return VD->hasGlobalStorage(); |
| return false; |
| } |
| |
| if (const CompoundLiteralExpr *CLE = dyn_cast<CompoundLiteralExpr>(E)) |
| return CLE->isFileScope(); |
| |
| return true; |
| } |
| |
| static bool EvalPointerValueAsBool(LValue& Value, bool& Result) { |
| const Expr* Base = Value.Base; |
| |
| // A null base expression indicates a null pointer. These are always |
| // evaluatable, and they are false unless the offset is zero. |
| if (!Base) { |
| Result = !Value.Offset.isZero(); |
| return true; |
| } |
| |
| // Require the base expression to be a global l-value. |
| if (!IsGlobalLValue(Base)) return false; |
| |
| // We have a non-null base expression. These are generally known to |
| // be true, but if it'a decl-ref to a weak symbol it can be null at |
| // runtime. |
| Result = true; |
| |
| const DeclRefExpr* DeclRef = dyn_cast<DeclRefExpr>(Base); |
| if (!DeclRef) |
| return true; |
| |
| // If it's a weak symbol, it isn't constant-evaluable. |
| const ValueDecl* Decl = DeclRef->getDecl(); |
| if (Decl->hasAttr<WeakAttr>() || |
| Decl->hasAttr<WeakRefAttr>() || |
| Decl->hasAttr<WeakImportAttr>()) |
| return false; |
| |
| return true; |
| } |
| |
| static bool HandleConversionToBool(const Expr* E, bool& Result, |
| EvalInfo &Info) { |
| if (E->getType()->isIntegralOrEnumerationType()) { |
| APSInt IntResult; |
| if (!EvaluateInteger(E, IntResult, Info)) |
| return false; |
| Result = IntResult != 0; |
| return true; |
| } else if (E->getType()->isRealFloatingType()) { |
| APFloat FloatResult(0.0); |
| if (!EvaluateFloat(E, FloatResult, Info)) |
| return false; |
| Result = !FloatResult.isZero(); |
| return true; |
| } else if (E->getType()->hasPointerRepresentation()) { |
| LValue PointerResult; |
| if (!EvaluatePointer(E, PointerResult, Info)) |
| return false; |
| return EvalPointerValueAsBool(PointerResult, Result); |
| } else if (E->getType()->isAnyComplexType()) { |
| ComplexValue ComplexResult; |
| if (!EvaluateComplex(E, ComplexResult, Info)) |
| return false; |
| if (ComplexResult.isComplexFloat()) { |
| Result = !ComplexResult.getComplexFloatReal().isZero() || |
| !ComplexResult.getComplexFloatImag().isZero(); |
| } else { |
| Result = ComplexResult.getComplexIntReal().getBoolValue() || |
| ComplexResult.getComplexIntImag().getBoolValue(); |
| } |
| return true; |
| } |
| |
| return false; |
| } |
| |
| static APSInt HandleFloatToIntCast(QualType DestType, QualType SrcType, |
| APFloat &Value, ASTContext &Ctx) { |
| unsigned DestWidth = Ctx.getIntWidth(DestType); |
| // Determine whether we are converting to unsigned or signed. |
| bool DestSigned = DestType->isSignedIntegerType(); |
| |
| // FIXME: Warning for overflow. |
| uint64_t Space[4]; |
| bool ignored; |
| (void)Value.convertToInteger(Space, DestWidth, DestSigned, |
| llvm::APFloat::rmTowardZero, &ignored); |
| return APSInt(llvm::APInt(DestWidth, 4, Space), !DestSigned); |
| } |
| |
| static APFloat HandleFloatToFloatCast(QualType DestType, QualType SrcType, |
| APFloat &Value, ASTContext &Ctx) { |
| bool ignored; |
| APFloat Result = Value; |
| Result.convert(Ctx.getFloatTypeSemantics(DestType), |
| APFloat::rmNearestTiesToEven, &ignored); |
| return Result; |
| } |
| |
| static APSInt HandleIntToIntCast(QualType DestType, QualType SrcType, |
| APSInt &Value, ASTContext &Ctx) { |
| unsigned DestWidth = Ctx.getIntWidth(DestType); |
| APSInt Result = Value; |
| // Figure out if this is a truncate, extend or noop cast. |
| // If the input is signed, do a sign extend, noop, or truncate. |
| Result.extOrTrunc(DestWidth); |
| Result.setIsUnsigned(DestType->isUnsignedIntegerType()); |
| return Result; |
| } |
| |
| static APFloat HandleIntToFloatCast(QualType DestType, QualType SrcType, |
| APSInt &Value, ASTContext &Ctx) { |
| |
| APFloat Result(Ctx.getFloatTypeSemantics(DestType), 1); |
| Result.convertFromAPInt(Value, Value.isSigned(), |
| APFloat::rmNearestTiesToEven); |
| return Result; |
| } |
| |
| namespace { |
| class HasSideEffect |
| : public StmtVisitor<HasSideEffect, bool> { |
| EvalInfo &Info; |
| public: |
| |
| HasSideEffect(EvalInfo &info) : Info(info) {} |
| |
| // Unhandled nodes conservatively default to having side effects. |
| bool VisitStmt(Stmt *S) { |
| return true; |
| } |
| |
| bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
| bool VisitDeclRefExpr(DeclRefExpr *E) { |
| if (Info.Ctx.getCanonicalType(E->getType()).isVolatileQualified()) |
| return true; |
| return false; |
| } |
| // We don't want to evaluate BlockExprs multiple times, as they generate |
| // a ton of code. |
| bool VisitBlockExpr(BlockExpr *E) { return true; } |
| bool VisitPredefinedExpr(PredefinedExpr *E) { return false; } |
| bool VisitCompoundLiteralExpr(CompoundLiteralExpr *E) |
| { return Visit(E->getInitializer()); } |
| bool VisitMemberExpr(MemberExpr *E) { return Visit(E->getBase()); } |
| bool VisitIntegerLiteral(IntegerLiteral *E) { return false; } |
| bool VisitFloatingLiteral(FloatingLiteral *E) { return false; } |
| bool VisitStringLiteral(StringLiteral *E) { return false; } |
| bool VisitCharacterLiteral(CharacterLiteral *E) { return false; } |
| bool VisitSizeOfAlignOfExpr(SizeOfAlignOfExpr *E) { return false; } |
| bool VisitArraySubscriptExpr(ArraySubscriptExpr *E) |
| { return Visit(E->getLHS()) || Visit(E->getRHS()); } |
| bool VisitChooseExpr(ChooseExpr *E) |
| { return Visit(E->getChosenSubExpr(Info.Ctx)); } |
| bool VisitCastExpr(CastExpr *E) { return Visit(E->getSubExpr()); } |
| bool VisitBinAssign(BinaryOperator *E) { return true; } |
| bool VisitCompoundAssignOperator(BinaryOperator *E) { return true; } |
| bool VisitBinaryOperator(BinaryOperator *E) |
| { return Visit(E->getLHS()) || Visit(E->getRHS()); } |
| bool VisitUnaryPreInc(UnaryOperator *E) { return true; } |
| bool VisitUnaryPostInc(UnaryOperator *E) { return true; } |
| bool VisitUnaryPreDec(UnaryOperator *E) { return true; } |
| bool VisitUnaryPostDec(UnaryOperator *E) { return true; } |
| bool VisitUnaryDeref(UnaryOperator *E) { |
| if (Info.Ctx.getCanonicalType(E->getType()).isVolatileQualified()) |
| return true; |
| return Visit(E->getSubExpr()); |
| } |
| bool VisitUnaryOperator(UnaryOperator *E) { return Visit(E->getSubExpr()); } |
| |
| // Has side effects if any element does. |
| bool VisitInitListExpr(InitListExpr *E) { |
| for (unsigned i = 0, e = E->getNumInits(); i != e; ++i) |
| if (Visit(E->getInit(i))) return true; |
| return false; |
| } |
| }; |
| |
| } // end anonymous namespace |
| |
| //===----------------------------------------------------------------------===// |
| // LValue Evaluation |
| //===----------------------------------------------------------------------===// |
| namespace { |
| class LValueExprEvaluator |
| : public StmtVisitor<LValueExprEvaluator, bool> { |
| EvalInfo &Info; |
| LValue &Result; |
| |
| bool Success(Expr *E) { |
| Result.Base = E; |
| Result.Offset = CharUnits::Zero(); |
| return true; |
| } |
| public: |
| |
| LValueExprEvaluator(EvalInfo &info, LValue &Result) : |
| Info(info), Result(Result) {} |
| |
| bool VisitStmt(Stmt *S) { |
| return false; |
| } |
| |
| bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
| bool VisitDeclRefExpr(DeclRefExpr *E); |
| bool VisitPredefinedExpr(PredefinedExpr *E) { return Success(E); } |
| bool VisitCompoundLiteralExpr(CompoundLiteralExpr *E); |
| bool VisitMemberExpr(MemberExpr *E); |
| bool VisitStringLiteral(StringLiteral *E) { return Success(E); } |
| bool VisitObjCEncodeExpr(ObjCEncodeExpr *E) { return Success(E); } |
| bool VisitArraySubscriptExpr(ArraySubscriptExpr *E); |
| bool VisitUnaryDeref(UnaryOperator *E); |
| bool VisitUnaryExtension(const UnaryOperator *E) |
| { return Visit(E->getSubExpr()); } |
| bool VisitChooseExpr(const ChooseExpr *E) |
| { return Visit(E->getChosenSubExpr(Info.Ctx)); } |
| |
| bool VisitCastExpr(CastExpr *E) { |
| switch (E->getCastKind()) { |
| default: |
| return false; |
| |
| case CK_NoOp: |
| return Visit(E->getSubExpr()); |
| } |
| } |
| // FIXME: Missing: __real__, __imag__ |
| }; |
| } // end anonymous namespace |
| |
| static bool EvaluateLValue(const Expr* E, LValue& Result, EvalInfo &Info) { |
| return LValueExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E)); |
| } |
| |
| bool LValueExprEvaluator::VisitDeclRefExpr(DeclRefExpr *E) { |
| if (isa<FunctionDecl>(E->getDecl())) { |
| return Success(E); |
| } else if (VarDecl* VD = dyn_cast<VarDecl>(E->getDecl())) { |
| if (!VD->getType()->isReferenceType()) |
| return Success(E); |
| // Reference parameters can refer to anything even if they have an |
| // "initializer" in the form of a default argument. |
| if (isa<ParmVarDecl>(VD)) |
| return false; |
| // FIXME: Check whether VD might be overridden! |
| if (const Expr *Init = VD->getAnyInitializer()) |
| return Visit(const_cast<Expr *>(Init)); |
| } |
| |
| return false; |
| } |
| |
| bool LValueExprEvaluator::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { |
| return Success(E); |
| } |
| |
| bool LValueExprEvaluator::VisitMemberExpr(MemberExpr *E) { |
| QualType Ty; |
| if (E->isArrow()) { |
| if (!EvaluatePointer(E->getBase(), Result, Info)) |
| return false; |
| Ty = E->getBase()->getType()->getAs<PointerType>()->getPointeeType(); |
| } else { |
| if (!Visit(E->getBase())) |
| return false; |
| Ty = E->getBase()->getType(); |
| } |
| |
| RecordDecl *RD = Ty->getAs<RecordType>()->getDecl(); |
| const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD); |
| |
| FieldDecl *FD = dyn_cast<FieldDecl>(E->getMemberDecl()); |
| if (!FD) // FIXME: deal with other kinds of member expressions |
| return false; |
| |
| if (FD->getType()->isReferenceType()) |
| return false; |
| |
| // FIXME: This is linear time. |
| unsigned i = 0; |
| for (RecordDecl::field_iterator Field = RD->field_begin(), |
| FieldEnd = RD->field_end(); |
| Field != FieldEnd; (void)++Field, ++i) { |
| if (*Field == FD) |
| break; |
| } |
| |
| Result.Offset += CharUnits::fromQuantity(RL.getFieldOffset(i) / 8); |
| return true; |
| } |
| |
| bool LValueExprEvaluator::VisitArraySubscriptExpr(ArraySubscriptExpr *E) { |
| if (!EvaluatePointer(E->getBase(), Result, Info)) |
| return false; |
| |
| APSInt Index; |
| if (!EvaluateInteger(E->getIdx(), Index, Info)) |
| return false; |
| |
| CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(E->getType()); |
| Result.Offset += Index.getSExtValue() * ElementSize; |
| return true; |
| } |
| |
| bool LValueExprEvaluator::VisitUnaryDeref(UnaryOperator *E) { |
| return EvaluatePointer(E->getSubExpr(), Result, Info); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Pointer Evaluation |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class PointerExprEvaluator |
| : public StmtVisitor<PointerExprEvaluator, bool> { |
| EvalInfo &Info; |
| LValue &Result; |
| |
| bool Success(Expr *E) { |
| Result.Base = E; |
| Result.Offset = CharUnits::Zero(); |
| return true; |
| } |
| public: |
| |
| PointerExprEvaluator(EvalInfo &info, LValue &Result) |
| : Info(info), Result(Result) {} |
| |
| bool VisitStmt(Stmt *S) { |
| return false; |
| } |
| |
| bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
| |
| bool VisitBinaryOperator(const BinaryOperator *E); |
| bool VisitCastExpr(CastExpr* E); |
| bool VisitUnaryExtension(const UnaryOperator *E) |
| { return Visit(E->getSubExpr()); } |
| bool VisitUnaryAddrOf(const UnaryOperator *E); |
| bool VisitObjCStringLiteral(ObjCStringLiteral *E) |
| { return Success(E); } |
| bool VisitAddrLabelExpr(AddrLabelExpr *E) |
| { return Success(E); } |
| bool VisitCallExpr(CallExpr *E); |
| bool VisitBlockExpr(BlockExpr *E) { |
| if (!E->hasBlockDeclRefExprs()) |
| return Success(E); |
| return false; |
| } |
| bool VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) |
| { return Success((Expr*)0); } |
| bool VisitConditionalOperator(ConditionalOperator *E); |
| bool VisitChooseExpr(ChooseExpr *E) |
| { return Visit(E->getChosenSubExpr(Info.Ctx)); } |
| bool VisitCXXNullPtrLiteralExpr(CXXNullPtrLiteralExpr *E) |
| { return Success((Expr*)0); } |
| // FIXME: Missing: @protocol, @selector |
| }; |
| } // end anonymous namespace |
| |
| static bool EvaluatePointer(const Expr* E, LValue& Result, EvalInfo &Info) { |
| assert(E->getType()->hasPointerRepresentation()); |
| return PointerExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E)); |
| } |
| |
| bool PointerExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { |
| if (E->getOpcode() != BO_Add && |
| E->getOpcode() != BO_Sub) |
| return false; |
| |
| const Expr *PExp = E->getLHS(); |
| const Expr *IExp = E->getRHS(); |
| if (IExp->getType()->isPointerType()) |
| std::swap(PExp, IExp); |
| |
| if (!EvaluatePointer(PExp, Result, Info)) |
| return false; |
| |
| llvm::APSInt Offset; |
| if (!EvaluateInteger(IExp, Offset, Info)) |
| return false; |
| int64_t AdditionalOffset |
| = Offset.isSigned() ? Offset.getSExtValue() |
| : static_cast<int64_t>(Offset.getZExtValue()); |
| |
| // Compute the new offset in the appropriate width. |
| |
| QualType PointeeType = |
| PExp->getType()->getAs<PointerType>()->getPointeeType(); |
| CharUnits SizeOfPointee; |
| |
| // Explicitly handle GNU void* and function pointer arithmetic extensions. |
| if (PointeeType->isVoidType() || PointeeType->isFunctionType()) |
| SizeOfPointee = CharUnits::One(); |
| else |
| SizeOfPointee = Info.Ctx.getTypeSizeInChars(PointeeType); |
| |
| if (E->getOpcode() == BO_Add) |
| Result.Offset += AdditionalOffset * SizeOfPointee; |
| else |
| Result.Offset -= AdditionalOffset * SizeOfPointee; |
| |
| return true; |
| } |
| |
| bool PointerExprEvaluator::VisitUnaryAddrOf(const UnaryOperator *E) { |
| return EvaluateLValue(E->getSubExpr(), Result, Info); |
| } |
| |
| |
| bool PointerExprEvaluator::VisitCastExpr(CastExpr* E) { |
| Expr* SubExpr = E->getSubExpr(); |
| |
| switch (E->getCastKind()) { |
| default: |
| break; |
| |
| case CK_Unknown: { |
| // FIXME: The handling for CK_Unknown is ugly/shouldn't be necessary! |
| |
| // Check for pointer->pointer cast |
| if (SubExpr->getType()->isPointerType() || |
| SubExpr->getType()->isObjCObjectPointerType() || |
| SubExpr->getType()->isNullPtrType() || |
| SubExpr->getType()->isBlockPointerType()) |
| return Visit(SubExpr); |
| |
| if (SubExpr->getType()->isIntegralOrEnumerationType()) { |
| APValue Value; |
| if (!EvaluateIntegerOrLValue(SubExpr, Value, Info)) |
| break; |
| |
| if (Value.isInt()) { |
| Value.getInt().extOrTrunc((unsigned)Info.Ctx.getTypeSize(E->getType())); |
| Result.Base = 0; |
| Result.Offset = CharUnits::fromQuantity(Value.getInt().getZExtValue()); |
| return true; |
| } else { |
| Result.Base = Value.getLValueBase(); |
| Result.Offset = Value.getLValueOffset(); |
| return true; |
| } |
| } |
| break; |
| } |
| |
| case CK_NoOp: |
| case CK_BitCast: |
| case CK_LValueBitCast: |
| case CK_AnyPointerToObjCPointerCast: |
| case CK_AnyPointerToBlockPointerCast: |
| return Visit(SubExpr); |
| |
| case CK_IntegralToPointer: { |
| APValue Value; |
| if (!EvaluateIntegerOrLValue(SubExpr, Value, Info)) |
| break; |
| |
| if (Value.isInt()) { |
| Value.getInt().extOrTrunc((unsigned)Info.Ctx.getTypeSize(E->getType())); |
| Result.Base = 0; |
| Result.Offset = CharUnits::fromQuantity(Value.getInt().getZExtValue()); |
| return true; |
| } else { |
| // Cast is of an lvalue, no need to change value. |
| Result.Base = Value.getLValueBase(); |
| Result.Offset = Value.getLValueOffset(); |
| return true; |
| } |
| } |
| case CK_ArrayToPointerDecay: |
| case CK_FunctionToPointerDecay: |
| return EvaluateLValue(SubExpr, Result, Info); |
| } |
| |
| return false; |
| } |
| |
| bool PointerExprEvaluator::VisitCallExpr(CallExpr *E) { |
| if (E->isBuiltinCall(Info.Ctx) == |
| Builtin::BI__builtin___CFStringMakeConstantString || |
| E->isBuiltinCall(Info.Ctx) == |
| Builtin::BI__builtin___NSStringMakeConstantString) |
| return Success(E); |
| return false; |
| } |
| |
| bool PointerExprEvaluator::VisitConditionalOperator(ConditionalOperator *E) { |
| bool BoolResult; |
| if (!HandleConversionToBool(E->getCond(), BoolResult, Info)) |
| return false; |
| |
| Expr* EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr(); |
| return Visit(EvalExpr); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Vector Evaluation |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class VectorExprEvaluator |
| : public StmtVisitor<VectorExprEvaluator, APValue> { |
| EvalInfo &Info; |
| APValue GetZeroVector(QualType VecType); |
| public: |
| |
| VectorExprEvaluator(EvalInfo &info) : Info(info) {} |
| |
| APValue VisitStmt(Stmt *S) { |
| return APValue(); |
| } |
| |
| APValue VisitParenExpr(ParenExpr *E) |
| { return Visit(E->getSubExpr()); } |
| APValue VisitUnaryExtension(const UnaryOperator *E) |
| { return Visit(E->getSubExpr()); } |
| APValue VisitUnaryPlus(const UnaryOperator *E) |
| { return Visit(E->getSubExpr()); } |
| APValue VisitUnaryReal(const UnaryOperator *E) |
| { return Visit(E->getSubExpr()); } |
| APValue VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) |
| { return GetZeroVector(E->getType()); } |
| APValue VisitCastExpr(const CastExpr* E); |
| APValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E); |
| APValue VisitInitListExpr(const InitListExpr *E); |
| APValue VisitConditionalOperator(const ConditionalOperator *E); |
| APValue VisitChooseExpr(const ChooseExpr *E) |
| { return Visit(E->getChosenSubExpr(Info.Ctx)); } |
| APValue VisitUnaryImag(const UnaryOperator *E); |
| // FIXME: Missing: unary -, unary ~, binary add/sub/mul/div, |
| // binary comparisons, binary and/or/xor, |
| // shufflevector, ExtVectorElementExpr |
| // (Note that these require implementing conversions |
| // between vector types.) |
| }; |
| } // end anonymous namespace |
| |
| static bool EvaluateVector(const Expr* E, APValue& Result, EvalInfo &Info) { |
| if (!E->getType()->isVectorType()) |
| return false; |
| Result = VectorExprEvaluator(Info).Visit(const_cast<Expr*>(E)); |
| return !Result.isUninit(); |
| } |
| |
| APValue VectorExprEvaluator::VisitCastExpr(const CastExpr* E) { |
| const VectorType *VTy = E->getType()->getAs<VectorType>(); |
| QualType EltTy = VTy->getElementType(); |
| unsigned NElts = VTy->getNumElements(); |
| unsigned EltWidth = Info.Ctx.getTypeSize(EltTy); |
| |
| const Expr* SE = E->getSubExpr(); |
| QualType SETy = SE->getType(); |
| APValue Result = APValue(); |
| |
| // Check for vector->vector bitcast and scalar->vector splat. |
| if (SETy->isVectorType()) { |
| return this->Visit(const_cast<Expr*>(SE)); |
| } else if (SETy->isIntegerType()) { |
| APSInt IntResult; |
| if (!EvaluateInteger(SE, IntResult, Info)) |
| return APValue(); |
| Result = APValue(IntResult); |
| } else if (SETy->isRealFloatingType()) { |
| APFloat F(0.0); |
| if (!EvaluateFloat(SE, F, Info)) |
| return APValue(); |
| Result = APValue(F); |
| } else |
| return APValue(); |
| |
| // For casts of a scalar to ExtVector, convert the scalar to the element type |
| // and splat it to all elements. |
| if (E->getType()->isExtVectorType()) { |
| if (EltTy->isIntegerType() && Result.isInt()) |
| Result = APValue(HandleIntToIntCast(EltTy, SETy, Result.getInt(), |
| Info.Ctx)); |
| else if (EltTy->isIntegerType()) |
| Result = APValue(HandleFloatToIntCast(EltTy, SETy, Result.getFloat(), |
| Info.Ctx)); |
| else if (EltTy->isRealFloatingType() && Result.isInt()) |
| Result = APValue(HandleIntToFloatCast(EltTy, SETy, Result.getInt(), |
| Info.Ctx)); |
| else if (EltTy->isRealFloatingType()) |
| Result = APValue(HandleFloatToFloatCast(EltTy, SETy, Result.getFloat(), |
| Info.Ctx)); |
| else |
| return APValue(); |
| |
| // Splat and create vector APValue. |
| llvm::SmallVector<APValue, 4> Elts(NElts, Result); |
| return APValue(&Elts[0], Elts.size()); |
| } |
| |
| // For casts of a scalar to regular gcc-style vector type, bitcast the scalar |
| // to the vector. To construct the APValue vector initializer, bitcast the |
| // initializing value to an APInt, and shift out the bits pertaining to each |
| // element. |
| APSInt Init; |
| Init = Result.isInt() ? Result.getInt() : Result.getFloat().bitcastToAPInt(); |
| |
| llvm::SmallVector<APValue, 4> Elts; |
| for (unsigned i = 0; i != NElts; ++i) { |
| APSInt Tmp = Init; |
| Tmp.extOrTrunc(EltWidth); |
| |
| if (EltTy->isIntegerType()) |
| Elts.push_back(APValue(Tmp)); |
| else if (EltTy->isRealFloatingType()) |
| Elts.push_back(APValue(APFloat(Tmp))); |
| else |
| return APValue(); |
| |
| Init >>= EltWidth; |
| } |
| return APValue(&Elts[0], Elts.size()); |
| } |
| |
| APValue |
| VectorExprEvaluator::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) { |
| return this->Visit(const_cast<Expr*>(E->getInitializer())); |
| } |
| |
| APValue |
| VectorExprEvaluator::VisitInitListExpr(const InitListExpr *E) { |
| const VectorType *VT = E->getType()->getAs<VectorType>(); |
| unsigned NumInits = E->getNumInits(); |
| unsigned NumElements = VT->getNumElements(); |
| |
| QualType EltTy = VT->getElementType(); |
| llvm::SmallVector<APValue, 4> Elements; |
| |
| // If a vector is initialized with a single element, that value |
| // becomes every element of the vector, not just the first. |
| // This is the behavior described in the IBM AltiVec documentation. |
| if (NumInits == 1) { |
| APValue InitValue; |
| if (EltTy->isIntegerType()) { |
| llvm::APSInt sInt(32); |
| if (!EvaluateInteger(E->getInit(0), sInt, Info)) |
| return APValue(); |
| InitValue = APValue(sInt); |
| } else { |
| llvm::APFloat f(0.0); |
| if (!EvaluateFloat(E->getInit(0), f, Info)) |
| return APValue(); |
| InitValue = APValue(f); |
| } |
| for (unsigned i = 0; i < NumElements; i++) { |
| Elements.push_back(InitValue); |
| } |
| } else { |
| for (unsigned i = 0; i < NumElements; i++) { |
| if (EltTy->isIntegerType()) { |
| llvm::APSInt sInt(32); |
| if (i < NumInits) { |
| if (!EvaluateInteger(E->getInit(i), sInt, Info)) |
| return APValue(); |
| } else { |
| sInt = Info.Ctx.MakeIntValue(0, EltTy); |
| } |
| Elements.push_back(APValue(sInt)); |
| } else { |
| llvm::APFloat f(0.0); |
| if (i < NumInits) { |
| if (!EvaluateFloat(E->getInit(i), f, Info)) |
| return APValue(); |
| } else { |
| f = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy)); |
| } |
| Elements.push_back(APValue(f)); |
| } |
| } |
| } |
| return APValue(&Elements[0], Elements.size()); |
| } |
| |
| APValue |
| VectorExprEvaluator::GetZeroVector(QualType T) { |
| const VectorType *VT = T->getAs<VectorType>(); |
| QualType EltTy = VT->getElementType(); |
| APValue ZeroElement; |
| if (EltTy->isIntegerType()) |
| ZeroElement = APValue(Info.Ctx.MakeIntValue(0, EltTy)); |
| else |
| ZeroElement = |
| APValue(APFloat::getZero(Info.Ctx.getFloatTypeSemantics(EltTy))); |
| |
| llvm::SmallVector<APValue, 4> Elements(VT->getNumElements(), ZeroElement); |
| return APValue(&Elements[0], Elements.size()); |
| } |
| |
| APValue VectorExprEvaluator::VisitConditionalOperator(const ConditionalOperator *E) { |
| bool BoolResult; |
| if (!HandleConversionToBool(E->getCond(), BoolResult, Info)) |
| return APValue(); |
| |
| Expr* EvalExpr = BoolResult ? E->getTrueExpr() : E->getFalseExpr(); |
| |
| APValue Result; |
| if (EvaluateVector(EvalExpr, Result, Info)) |
| return Result; |
| return APValue(); |
| } |
| |
| APValue VectorExprEvaluator::VisitUnaryImag(const UnaryOperator *E) { |
| if (!E->getSubExpr()->isEvaluatable(Info.Ctx)) |
| Info.EvalResult.HasSideEffects = true; |
| return GetZeroVector(E->getType()); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Integer Evaluation |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class IntExprEvaluator |
| : public StmtVisitor<IntExprEvaluator, bool> { |
| EvalInfo &Info; |
| APValue &Result; |
| public: |
| IntExprEvaluator(EvalInfo &info, APValue &result) |
| : Info(info), Result(result) {} |
| |
| bool Success(const llvm::APSInt &SI, const Expr *E) { |
| assert(E->getType()->isIntegralOrEnumerationType() && |
| "Invalid evaluation result."); |
| assert(SI.isSigned() == E->getType()->isSignedIntegerType() && |
| "Invalid evaluation result."); |
| assert(SI.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && |
| "Invalid evaluation result."); |
| Result = APValue(SI); |
| return true; |
| } |
| |
| bool Success(const llvm::APInt &I, const Expr *E) { |
| assert(E->getType()->isIntegralOrEnumerationType() && |
| "Invalid evaluation result."); |
| assert(I.getBitWidth() == Info.Ctx.getIntWidth(E->getType()) && |
| "Invalid evaluation result."); |
| Result = APValue(APSInt(I)); |
| Result.getInt().setIsUnsigned(E->getType()->isUnsignedIntegerType()); |
| return true; |
| } |
| |
| bool Success(uint64_t Value, const Expr *E) { |
| assert(E->getType()->isIntegralOrEnumerationType() && |
| "Invalid evaluation result."); |
| Result = APValue(Info.Ctx.MakeIntValue(Value, E->getType())); |
| return true; |
| } |
| |
| bool Error(SourceLocation L, diag::kind D, const Expr *E) { |
| // Take the first error. |
| if (Info.EvalResult.Diag == 0) { |
| Info.EvalResult.DiagLoc = L; |
| Info.EvalResult.Diag = D; |
| Info.EvalResult.DiagExpr = E; |
| } |
| return false; |
| } |
| |
| //===--------------------------------------------------------------------===// |
| // Visitor Methods |
| //===--------------------------------------------------------------------===// |
| |
| bool VisitStmt(Stmt *) { |
| assert(0 && "This should be called on integers, stmts are not integers"); |
| return false; |
| } |
| |
| bool VisitExpr(Expr *E) { |
| return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E); |
| } |
| |
| bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
| |
| bool VisitIntegerLiteral(const IntegerLiteral *E) { |
| return Success(E->getValue(), E); |
| } |
| bool VisitCharacterLiteral(const CharacterLiteral *E) { |
| return Success(E->getValue(), E); |
| } |
| bool VisitTypesCompatibleExpr(const TypesCompatibleExpr *E) { |
| // Per gcc docs "this built-in function ignores top level |
| // qualifiers". We need to use the canonical version to properly |
| // be able to strip CRV qualifiers from the type. |
| QualType T0 = Info.Ctx.getCanonicalType(E->getArgType1()); |
| QualType T1 = Info.Ctx.getCanonicalType(E->getArgType2()); |
| return Success(Info.Ctx.typesAreCompatible(T0.getUnqualifiedType(), |
| T1.getUnqualifiedType()), |
| E); |
| } |
| |
| bool CheckReferencedDecl(const Expr *E, const Decl *D); |
| bool VisitDeclRefExpr(const DeclRefExpr *E) { |
| return CheckReferencedDecl(E, E->getDecl()); |
| } |
| bool VisitMemberExpr(const MemberExpr *E) { |
| if (CheckReferencedDecl(E, E->getMemberDecl())) { |
| // Conservatively assume a MemberExpr will have side-effects |
| Info.EvalResult.HasSideEffects = true; |
| return true; |
| } |
| return false; |
| } |
| |
| bool VisitCallExpr(CallExpr *E); |
| bool VisitBinaryOperator(const BinaryOperator *E); |
| bool VisitOffsetOfExpr(const OffsetOfExpr *E); |
| bool VisitUnaryOperator(const UnaryOperator *E); |
| bool VisitConditionalOperator(const ConditionalOperator *E); |
| |
| bool VisitCastExpr(CastExpr* E); |
| bool VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E); |
| |
| bool VisitCXXBoolLiteralExpr(const CXXBoolLiteralExpr *E) { |
| return Success(E->getValue(), E); |
| } |
| |
| bool VisitGNUNullExpr(const GNUNullExpr *E) { |
| return Success(0, E); |
| } |
| |
| bool VisitCXXScalarValueInitExpr(const CXXScalarValueInitExpr *E) { |
| return Success(0, E); |
| } |
| |
| bool VisitImplicitValueInitExpr(const ImplicitValueInitExpr *E) { |
| return Success(0, E); |
| } |
| |
| bool VisitUnaryTypeTraitExpr(const UnaryTypeTraitExpr *E) { |
| return Success(E->getValue(), E); |
| } |
| |
| bool VisitChooseExpr(const ChooseExpr *E) { |
| return Visit(E->getChosenSubExpr(Info.Ctx)); |
| } |
| |
| bool VisitUnaryReal(const UnaryOperator *E); |
| bool VisitUnaryImag(const UnaryOperator *E); |
| |
| bool VisitCXXNoexceptExpr(const CXXNoexceptExpr *E); |
| |
| private: |
| CharUnits GetAlignOfExpr(const Expr *E); |
| CharUnits GetAlignOfType(QualType T); |
| static QualType GetObjectType(const Expr *E); |
| bool TryEvaluateBuiltinObjectSize(CallExpr *E); |
| // FIXME: Missing: array subscript of vector, member of vector |
| }; |
| } // end anonymous namespace |
| |
| static bool EvaluateIntegerOrLValue(const Expr* E, APValue &Result, EvalInfo &Info) { |
| assert(E->getType()->isIntegralOrEnumerationType()); |
| return IntExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E)); |
| } |
| |
| static bool EvaluateInteger(const Expr* E, APSInt &Result, EvalInfo &Info) { |
| assert(E->getType()->isIntegralOrEnumerationType()); |
| |
| APValue Val; |
| if (!EvaluateIntegerOrLValue(E, Val, Info) || !Val.isInt()) |
| return false; |
| Result = Val.getInt(); |
| return true; |
| } |
| |
| bool IntExprEvaluator::CheckReferencedDecl(const Expr* E, const Decl* D) { |
| // Enums are integer constant exprs. |
| if (const EnumConstantDecl *ECD = dyn_cast<EnumConstantDecl>(D)) |
| return Success(ECD->getInitVal(), E); |
| |
| // In C++, const, non-volatile integers initialized with ICEs are ICEs. |
| // In C, they can also be folded, although they are not ICEs. |
| if (Info.Ctx.getCanonicalType(E->getType()).getCVRQualifiers() |
| == Qualifiers::Const) { |
| |
| if (isa<ParmVarDecl>(D)) |
| return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E); |
| |
| if (const VarDecl *VD = dyn_cast<VarDecl>(D)) { |
| if (const Expr *Init = VD->getAnyInitializer()) { |
| if (APValue *V = VD->getEvaluatedValue()) { |
| if (V->isInt()) |
| return Success(V->getInt(), E); |
| return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E); |
| } |
| |
| if (VD->isEvaluatingValue()) |
| return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E); |
| |
| VD->setEvaluatingValue(); |
| |
| Expr::EvalResult EResult; |
| if (Init->Evaluate(EResult, Info.Ctx) && !EResult.HasSideEffects && |
| EResult.Val.isInt()) { |
| // Cache the evaluated value in the variable declaration. |
| Result = EResult.Val; |
| VD->setEvaluatedValue(Result); |
| return true; |
| } |
| |
| VD->setEvaluatedValue(APValue()); |
| } |
| } |
| } |
| |
| // Otherwise, random variable references are not constants. |
| return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E); |
| } |
| |
| /// EvaluateBuiltinClassifyType - Evaluate __builtin_classify_type the same way |
| /// as GCC. |
| static int EvaluateBuiltinClassifyType(const CallExpr *E) { |
| // The following enum mimics the values returned by GCC. |
| // FIXME: Does GCC differ between lvalue and rvalue references here? |
| enum gcc_type_class { |
| no_type_class = -1, |
| void_type_class, integer_type_class, char_type_class, |
| enumeral_type_class, boolean_type_class, |
| pointer_type_class, reference_type_class, offset_type_class, |
| real_type_class, complex_type_class, |
| function_type_class, method_type_class, |
| record_type_class, union_type_class, |
| array_type_class, string_type_class, |
| lang_type_class |
| }; |
| |
| // If no argument was supplied, default to "no_type_class". This isn't |
| // ideal, however it is what gcc does. |
| if (E->getNumArgs() == 0) |
| return no_type_class; |
| |
| QualType ArgTy = E->getArg(0)->getType(); |
| if (ArgTy->isVoidType()) |
| return void_type_class; |
| else if (ArgTy->isEnumeralType()) |
| return enumeral_type_class; |
| else if (ArgTy->isBooleanType()) |
| return boolean_type_class; |
| else if (ArgTy->isCharType()) |
| return string_type_class; // gcc doesn't appear to use char_type_class |
| else if (ArgTy->isIntegerType()) |
| return integer_type_class; |
| else if (ArgTy->isPointerType()) |
| return pointer_type_class; |
| else if (ArgTy->isReferenceType()) |
| return reference_type_class; |
| else if (ArgTy->isRealType()) |
| return real_type_class; |
| else if (ArgTy->isComplexType()) |
| return complex_type_class; |
| else if (ArgTy->isFunctionType()) |
| return function_type_class; |
| else if (ArgTy->isStructureOrClassType()) |
| return record_type_class; |
| else if (ArgTy->isUnionType()) |
| return union_type_class; |
| else if (ArgTy->isArrayType()) |
| return array_type_class; |
| else if (ArgTy->isUnionType()) |
| return union_type_class; |
| else // FIXME: offset_type_class, method_type_class, & lang_type_class? |
| assert(0 && "CallExpr::isBuiltinClassifyType(): unimplemented type"); |
| return -1; |
| } |
| |
| /// Retrieves the "underlying object type" of the given expression, |
| /// as used by __builtin_object_size. |
| QualType IntExprEvaluator::GetObjectType(const Expr *E) { |
| if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) { |
| if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) |
| return VD->getType(); |
| } else if (isa<CompoundLiteralExpr>(E)) { |
| return E->getType(); |
| } |
| |
| return QualType(); |
| } |
| |
| bool IntExprEvaluator::TryEvaluateBuiltinObjectSize(CallExpr *E) { |
| // TODO: Perhaps we should let LLVM lower this? |
| LValue Base; |
| if (!EvaluatePointer(E->getArg(0), Base, Info)) |
| return false; |
| |
| // If we can prove the base is null, lower to zero now. |
| const Expr *LVBase = Base.getLValueBase(); |
| if (!LVBase) return Success(0, E); |
| |
| QualType T = GetObjectType(LVBase); |
| if (T.isNull() || |
| T->isIncompleteType() || |
| T->isFunctionType() || |
| T->isVariablyModifiedType() || |
| T->isDependentType()) |
| return false; |
| |
| CharUnits Size = Info.Ctx.getTypeSizeInChars(T); |
| CharUnits Offset = Base.getLValueOffset(); |
| |
| if (!Offset.isNegative() && Offset <= Size) |
| Size -= Offset; |
| else |
| Size = CharUnits::Zero(); |
| return Success(Size.getQuantity(), E); |
| } |
| |
| bool IntExprEvaluator::VisitCallExpr(CallExpr *E) { |
| switch (E->isBuiltinCall(Info.Ctx)) { |
| default: |
| return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E); |
| |
| case Builtin::BI__builtin_object_size: { |
| if (TryEvaluateBuiltinObjectSize(E)) |
| return true; |
| |
| // If evaluating the argument has side-effects we can't determine |
| // the size of the object and lower it to unknown now. |
| if (E->getArg(0)->HasSideEffects(Info.Ctx)) { |
| if (E->getArg(1)->EvaluateAsInt(Info.Ctx).getZExtValue() <= 1) |
| return Success(-1ULL, E); |
| return Success(0, E); |
| } |
| |
| return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E); |
| } |
| |
| case Builtin::BI__builtin_classify_type: |
| return Success(EvaluateBuiltinClassifyType(E), E); |
| |
| case Builtin::BI__builtin_constant_p: |
| // __builtin_constant_p always has one operand: it returns true if that |
| // operand can be folded, false otherwise. |
| return Success(E->getArg(0)->isEvaluatable(Info.Ctx), E); |
| |
| case Builtin::BI__builtin_eh_return_data_regno: { |
| int Operand = E->getArg(0)->EvaluateAsInt(Info.Ctx).getZExtValue(); |
| Operand = Info.Ctx.Target.getEHDataRegisterNumber(Operand); |
| return Success(Operand, E); |
| } |
| |
| case Builtin::BI__builtin_expect: |
| return Visit(E->getArg(0)); |
| |
| case Builtin::BIstrlen: |
| case Builtin::BI__builtin_strlen: |
| // As an extension, we support strlen() and __builtin_strlen() as constant |
| // expressions when the argument is a string literal. |
| if (StringLiteral *S |
| = dyn_cast<StringLiteral>(E->getArg(0)->IgnoreParenImpCasts())) { |
| // The string literal may have embedded null characters. Find the first |
| // one and truncate there. |
| llvm::StringRef Str = S->getString(); |
| llvm::StringRef::size_type Pos = Str.find(0); |
| if (Pos != llvm::StringRef::npos) |
| Str = Str.substr(0, Pos); |
| |
| return Success(Str.size(), E); |
| } |
| |
| return Error(E->getLocStart(), diag::note_invalid_subexpr_in_ice, E); |
| } |
| } |
| |
| bool IntExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { |
| if (E->getOpcode() == BO_Comma) { |
| if (!Visit(E->getRHS())) |
| return false; |
| |
| // If we can't evaluate the LHS, it might have side effects; |
| // conservatively mark it. |
| if (!E->getLHS()->isEvaluatable(Info.Ctx)) |
| Info.EvalResult.HasSideEffects = true; |
| |
| return true; |
| } |
| |
| if (E->isLogicalOp()) { |
| // These need to be handled specially because the operands aren't |
| // necessarily integral |
| bool lhsResult, rhsResult; |
| |
| if (HandleConversionToBool(E->getLHS(), lhsResult, Info)) { |
| // We were able to evaluate the LHS, see if we can get away with not |
| // evaluating the RHS: 0 && X -> 0, 1 || X -> 1 |
| if (lhsResult == (E->getOpcode() == BO_LOr)) |
| return Success(lhsResult, E); |
| |
| if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) { |
| if (E->getOpcode() == BO_LOr) |
| return Success(lhsResult || rhsResult, E); |
| else |
| return Success(lhsResult && rhsResult, E); |
| } |
| } else { |
| if (HandleConversionToBool(E->getRHS(), rhsResult, Info)) { |
| // We can't evaluate the LHS; however, sometimes the result |
| // is determined by the RHS: X && 0 -> 0, X || 1 -> 1. |
| if (rhsResult == (E->getOpcode() == BO_LOr) || |
| !rhsResult == (E->getOpcode() == BO_LAnd)) { |
| // Since we weren't able to evaluate the left hand side, it |
| // must have had side effects. |
| Info.EvalResult.HasSideEffects = true; |
| |
| return Success(rhsResult, E); |
| } |
| } |
| } |
| |
| return false; |
| } |
| |
| QualType LHSTy = E->getLHS()->getType(); |
| QualType RHSTy = E->getRHS()->getType(); |
| |
| if (LHSTy->isAnyComplexType()) { |
| assert(RHSTy->isAnyComplexType() && "Invalid comparison"); |
| ComplexValue LHS, RHS; |
| |
| if (!EvaluateComplex(E->getLHS(), LHS, Info)) |
| return false; |
| |
| if (!EvaluateComplex(E->getRHS(), RHS, Info)) |
| return false; |
| |
| if (LHS.isComplexFloat()) { |
| APFloat::cmpResult CR_r = |
| LHS.getComplexFloatReal().compare(RHS.getComplexFloatReal()); |
| APFloat::cmpResult CR_i = |
| LHS.getComplexFloatImag().compare(RHS.getComplexFloatImag()); |
| |
| if (E->getOpcode() == BO_EQ) |
| return Success((CR_r == APFloat::cmpEqual && |
| CR_i == APFloat::cmpEqual), E); |
| else { |
| assert(E->getOpcode() == BO_NE && |
| "Invalid complex comparison."); |
| return Success(((CR_r == APFloat::cmpGreaterThan || |
| CR_r == APFloat::cmpLessThan || |
| CR_r == APFloat::cmpUnordered) || |
| (CR_i == APFloat::cmpGreaterThan || |
| CR_i == APFloat::cmpLessThan || |
| CR_i == APFloat::cmpUnordered)), E); |
| } |
| } else { |
| if (E->getOpcode() == BO_EQ) |
| return Success((LHS.getComplexIntReal() == RHS.getComplexIntReal() && |
| LHS.getComplexIntImag() == RHS.getComplexIntImag()), E); |
| else { |
| assert(E->getOpcode() == BO_NE && |
| "Invalid compex comparison."); |
| return Success((LHS.getComplexIntReal() != RHS.getComplexIntReal() || |
| LHS.getComplexIntImag() != RHS.getComplexIntImag()), E); |
| } |
| } |
| } |
| |
| if (LHSTy->isRealFloatingType() && |
| RHSTy->isRealFloatingType()) { |
| APFloat RHS(0.0), LHS(0.0); |
| |
| if (!EvaluateFloat(E->getRHS(), RHS, Info)) |
| return false; |
| |
| if (!EvaluateFloat(E->getLHS(), LHS, Info)) |
| return false; |
| |
| APFloat::cmpResult CR = LHS.compare(RHS); |
| |
| switch (E->getOpcode()) { |
| default: |
| assert(0 && "Invalid binary operator!"); |
| case BO_LT: |
| return Success(CR == APFloat::cmpLessThan, E); |
| case BO_GT: |
| return Success(CR == APFloat::cmpGreaterThan, E); |
| case BO_LE: |
| return Success(CR == APFloat::cmpLessThan || CR == APFloat::cmpEqual, E); |
| case BO_GE: |
| return Success(CR == APFloat::cmpGreaterThan || CR == APFloat::cmpEqual, |
| E); |
| case BO_EQ: |
| return Success(CR == APFloat::cmpEqual, E); |
| case BO_NE: |
| return Success(CR == APFloat::cmpGreaterThan |
| || CR == APFloat::cmpLessThan |
| || CR == APFloat::cmpUnordered, E); |
| } |
| } |
| |
| if (LHSTy->isPointerType() && RHSTy->isPointerType()) { |
| if (E->getOpcode() == BO_Sub || E->isEqualityOp()) { |
| LValue LHSValue; |
| if (!EvaluatePointer(E->getLHS(), LHSValue, Info)) |
| return false; |
| |
| LValue RHSValue; |
| if (!EvaluatePointer(E->getRHS(), RHSValue, Info)) |
| return false; |
| |
| // Reject any bases from the normal codepath; we special-case comparisons |
| // to null. |
| if (LHSValue.getLValueBase()) { |
| if (!E->isEqualityOp()) |
| return false; |
| if (RHSValue.getLValueBase() || !RHSValue.getLValueOffset().isZero()) |
| return false; |
| bool bres; |
| if (!EvalPointerValueAsBool(LHSValue, bres)) |
| return false; |
| return Success(bres ^ (E->getOpcode() == BO_EQ), E); |
| } else if (RHSValue.getLValueBase()) { |
| if (!E->isEqualityOp()) |
| return false; |
| if (LHSValue.getLValueBase() || !LHSValue.getLValueOffset().isZero()) |
| return false; |
| bool bres; |
| if (!EvalPointerValueAsBool(RHSValue, bres)) |
| return false; |
| return Success(bres ^ (E->getOpcode() == BO_EQ), E); |
| } |
| |
| if (E->getOpcode() == BO_Sub) { |
| QualType Type = E->getLHS()->getType(); |
| QualType ElementType = Type->getAs<PointerType>()->getPointeeType(); |
| |
| CharUnits ElementSize = CharUnits::One(); |
| if (!ElementType->isVoidType() && !ElementType->isFunctionType()) |
| ElementSize = Info.Ctx.getTypeSizeInChars(ElementType); |
| |
| CharUnits Diff = LHSValue.getLValueOffset() - |
| RHSValue.getLValueOffset(); |
| return Success(Diff / ElementSize, E); |
| } |
| bool Result; |
| if (E->getOpcode() == BO_EQ) { |
| Result = LHSValue.getLValueOffset() == RHSValue.getLValueOffset(); |
| } else { |
| Result = LHSValue.getLValueOffset() != RHSValue.getLValueOffset(); |
| } |
| return Success(Result, E); |
| } |
| } |
| if (!LHSTy->isIntegralOrEnumerationType() || |
| !RHSTy->isIntegralOrEnumerationType()) { |
| // We can't continue from here for non-integral types, and they |
| // could potentially confuse the following operations. |
| return false; |
| } |
| |
| // The LHS of a constant expr is always evaluated and needed. |
| if (!Visit(E->getLHS())) |
| return false; // error in subexpression. |
| |
| APValue RHSVal; |
| if (!EvaluateIntegerOrLValue(E->getRHS(), RHSVal, Info)) |
| return false; |
| |
| // Handle cases like (unsigned long)&a + 4. |
| if (E->isAdditiveOp() && Result.isLValue() && RHSVal.isInt()) { |
| CharUnits Offset = Result.getLValueOffset(); |
| CharUnits AdditionalOffset = CharUnits::fromQuantity( |
| RHSVal.getInt().getZExtValue()); |
| if (E->getOpcode() == BO_Add) |
| Offset += AdditionalOffset; |
| else |
| Offset -= AdditionalOffset; |
| Result = APValue(Result.getLValueBase(), Offset); |
| return true; |
| } |
| |
| // Handle cases like 4 + (unsigned long)&a |
| if (E->getOpcode() == BO_Add && |
| RHSVal.isLValue() && Result.isInt()) { |
| CharUnits Offset = RHSVal.getLValueOffset(); |
| Offset += CharUnits::fromQuantity(Result.getInt().getZExtValue()); |
| Result = APValue(RHSVal.getLValueBase(), Offset); |
| return true; |
| } |
| |
| // All the following cases expect both operands to be an integer |
| if (!Result.isInt() || !RHSVal.isInt()) |
| return false; |
| |
| APSInt& RHS = RHSVal.getInt(); |
| |
| switch (E->getOpcode()) { |
| default: |
| return Error(E->getOperatorLoc(), diag::note_invalid_subexpr_in_ice, E); |
| case BO_Mul: return Success(Result.getInt() * RHS, E); |
| case BO_Add: return Success(Result.getInt() + RHS, E); |
| case BO_Sub: return Success(Result.getInt() - RHS, E); |
| case BO_And: return Success(Result.getInt() & RHS, E); |
| case BO_Xor: return Success(Result.getInt() ^ RHS, E); |
| case BO_Or: return Success(Result.getInt() | RHS, E); |
| case BO_Div: |
| if (RHS == 0) |
| return Error(E->getOperatorLoc(), diag::note_expr_divide_by_zero, E); |
| return Success(Result.getInt() / RHS, E); |
| case BO_Rem: |
| if (RHS == 0) |
| return Error(E->getOperatorLoc(), diag::note_expr_divide_by_zero, E); |
| return Success(Result.getInt() % RHS, E); |
| case BO_Shl: { |
| // FIXME: Warn about out of range shift amounts! |
| unsigned SA = |
| (unsigned) RHS.getLimitedValue(Result.getInt().getBitWidth()-1); |
| return Success(Result.getInt() << SA, E); |
| } |
| case BO_Shr: { |
| unsigned SA = |
| (unsigned) RHS.getLimitedValue(Result.getInt().getBitWidth()-1); |
| return Success(Result.getInt() >> SA, E); |
| } |
| |
| case BO_LT: return Success(Result.getInt() < RHS, E); |
| case BO_GT: return Success(Result.getInt() > RHS, E); |
| case BO_LE: return Success(Result.getInt() <= RHS, E); |
| case BO_GE: return Success(Result.getInt() >= RHS, E); |
| case BO_EQ: return Success(Result.getInt() == RHS, E); |
| case BO_NE: return Success(Result.getInt() != RHS, E); |
| } |
| } |
| |
| bool IntExprEvaluator::VisitConditionalOperator(const ConditionalOperator *E) { |
| bool Cond; |
| if (!HandleConversionToBool(E->getCond(), Cond, Info)) |
| return false; |
| |
| return Visit(Cond ? E->getTrueExpr() : E->getFalseExpr()); |
| } |
| |
| CharUnits IntExprEvaluator::GetAlignOfType(QualType T) { |
| // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, |
| // the result is the size of the referenced type." |
| // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the |
| // result shall be the alignment of the referenced type." |
| if (const ReferenceType *Ref = T->getAs<ReferenceType>()) |
| T = Ref->getPointeeType(); |
| |
| // Get information about the alignment. |
| unsigned CharSize = Info.Ctx.Target.getCharWidth(); |
| |
| // __alignof is defined to return the preferred alignment. |
| return CharUnits::fromQuantity( |
| Info.Ctx.getPreferredTypeAlign(T.getTypePtr()) / CharSize); |
| } |
| |
| CharUnits IntExprEvaluator::GetAlignOfExpr(const Expr *E) { |
| E = E->IgnoreParens(); |
| |
| // alignof decl is always accepted, even if it doesn't make sense: we default |
| // to 1 in those cases. |
| if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) |
| return Info.Ctx.getDeclAlign(DRE->getDecl(), |
| /*RefAsPointee*/true); |
| |
| if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) |
| return Info.Ctx.getDeclAlign(ME->getMemberDecl(), |
| /*RefAsPointee*/true); |
| |
| return GetAlignOfType(E->getType()); |
| } |
| |
| |
| /// VisitSizeAlignOfExpr - Evaluate a sizeof or alignof with a result as the |
| /// expression's type. |
| bool IntExprEvaluator::VisitSizeOfAlignOfExpr(const SizeOfAlignOfExpr *E) { |
| // Handle alignof separately. |
| if (!E->isSizeOf()) { |
| if (E->isArgumentType()) |
| return Success(GetAlignOfType(E->getArgumentType()).getQuantity(), E); |
| else |
| return Success(GetAlignOfExpr(E->getArgumentExpr()).getQuantity(), E); |
| } |
| |
| QualType SrcTy = E->getTypeOfArgument(); |
| // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, |
| // the result is the size of the referenced type." |
| // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the |
| // result shall be the alignment of the referenced type." |
| if (const ReferenceType *Ref = SrcTy->getAs<ReferenceType>()) |
| SrcTy = Ref->getPointeeType(); |
| |
| // sizeof(void), __alignof__(void), sizeof(function) = 1 as a gcc |
| // extension. |
| if (SrcTy->isVoidType() || SrcTy->isFunctionType()) |
| return Success(1, E); |
| |
| // sizeof(vla) is not a constantexpr: C99 6.5.3.4p2. |
| if (!SrcTy->isConstantSizeType()) |
| return false; |
| |
| // Get information about the size. |
| return Success(Info.Ctx.getTypeSizeInChars(SrcTy).getQuantity(), E); |
| } |
| |
| bool IntExprEvaluator::VisitOffsetOfExpr(const OffsetOfExpr *E) { |
| CharUnits Result; |
| unsigned n = E->getNumComponents(); |
| OffsetOfExpr* OOE = const_cast<OffsetOfExpr*>(E); |
| if (n == 0) |
| return false; |
| QualType CurrentType = E->getTypeSourceInfo()->getType(); |
| for (unsigned i = 0; i != n; ++i) { |
| OffsetOfExpr::OffsetOfNode ON = OOE->getComponent(i); |
| switch (ON.getKind()) { |
| case OffsetOfExpr::OffsetOfNode::Array: { |
| Expr *Idx = OOE->getIndexExpr(ON.getArrayExprIndex()); |
| APSInt IdxResult; |
| if (!EvaluateInteger(Idx, IdxResult, Info)) |
| return false; |
| const ArrayType *AT = Info.Ctx.getAsArrayType(CurrentType); |
| if (!AT) |
| return false; |
| CurrentType = AT->getElementType(); |
| CharUnits ElementSize = Info.Ctx.getTypeSizeInChars(CurrentType); |
| Result += IdxResult.getSExtValue() * ElementSize; |
| break; |
| } |
| |
| case OffsetOfExpr::OffsetOfNode::Field: { |
| FieldDecl *MemberDecl = ON.getField(); |
| const RecordType *RT = CurrentType->getAs<RecordType>(); |
| if (!RT) |
| return false; |
| RecordDecl *RD = RT->getDecl(); |
| const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD); |
| unsigned i = 0; |
| // FIXME: It would be nice if we didn't have to loop here! |
| for (RecordDecl::field_iterator Field = RD->field_begin(), |
| FieldEnd = RD->field_end(); |
| Field != FieldEnd; (void)++Field, ++i) { |
| if (*Field == MemberDecl) |
| break; |
| } |
| assert(i < RL.getFieldCount() && "offsetof field in wrong type"); |
| Result += CharUnits::fromQuantity( |
| RL.getFieldOffset(i) / Info.Ctx.getCharWidth()); |
| CurrentType = MemberDecl->getType().getNonReferenceType(); |
| break; |
| } |
| |
| case OffsetOfExpr::OffsetOfNode::Identifier: |
| llvm_unreachable("dependent __builtin_offsetof"); |
| return false; |
| |
| case OffsetOfExpr::OffsetOfNode::Base: { |
| CXXBaseSpecifier *BaseSpec = ON.getBase(); |
| if (BaseSpec->isVirtual()) |
| return false; |
| |
| // Find the layout of the class whose base we are looking into. |
| const RecordType *RT = CurrentType->getAs<RecordType>(); |
| if (!RT) |
| return false; |
| RecordDecl *RD = RT->getDecl(); |
| const ASTRecordLayout &RL = Info.Ctx.getASTRecordLayout(RD); |
| |
| // Find the base class itself. |
| CurrentType = BaseSpec->getType(); |
| const RecordType *BaseRT = CurrentType->getAs<RecordType>(); |
| if (!BaseRT) |
| return false; |
| |
| // Add the offset to the base. |
| Result += CharUnits::fromQuantity( |
| RL.getBaseClassOffset(cast<CXXRecordDecl>(BaseRT->getDecl())) |
| / Info.Ctx.getCharWidth()); |
| break; |
| } |
| } |
| } |
| return Success(Result.getQuantity(), E); |
| } |
| |
| bool IntExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) { |
| if (E->getOpcode() == UO_LNot) { |
| // LNot's operand isn't necessarily an integer, so we handle it specially. |
| bool bres; |
| if (!HandleConversionToBool(E->getSubExpr(), bres, Info)) |
| return false; |
| return Success(!bres, E); |
| } |
| |
| // Only handle integral operations... |
| if (!E->getSubExpr()->getType()->isIntegralOrEnumerationType()) |
| return false; |
| |
| // Get the operand value into 'Result'. |
| if (!Visit(E->getSubExpr())) |
| return false; |
| |
| switch (E->getOpcode()) { |
| default: |
| // Address, indirect, pre/post inc/dec, etc are not valid constant exprs. |
| // See C99 6.6p3. |
| return Error(E->getOperatorLoc(), diag::note_invalid_subexpr_in_ice, E); |
| case UO_Extension: |
| // FIXME: Should extension allow i-c-e extension expressions in its scope? |
| // If so, we could clear the diagnostic ID. |
| return true; |
| case UO_Plus: |
| // The result is always just the subexpr. |
| return true; |
| case UO_Minus: |
| if (!Result.isInt()) return false; |
| return Success(-Result.getInt(), E); |
| case UO_Not: |
| if (!Result.isInt()) return false; |
| return Success(~Result.getInt(), E); |
| } |
| } |
| |
| /// HandleCast - This is used to evaluate implicit or explicit casts where the |
| /// result type is integer. |
| bool IntExprEvaluator::VisitCastExpr(CastExpr *E) { |
| Expr *SubExpr = E->getSubExpr(); |
| QualType DestType = E->getType(); |
| QualType SrcType = SubExpr->getType(); |
| |
| if (DestType->isBooleanType()) { |
| bool BoolResult; |
| if (!HandleConversionToBool(SubExpr, BoolResult, Info)) |
| return false; |
| return Success(BoolResult, E); |
| } |
| |
| // Handle simple integer->integer casts. |
| if (SrcType->isIntegralOrEnumerationType()) { |
| if (!Visit(SubExpr)) |
| return false; |
| |
| if (!Result.isInt()) { |
| // Only allow casts of lvalues if they are lossless. |
| return Info.Ctx.getTypeSize(DestType) == Info.Ctx.getTypeSize(SrcType); |
| } |
| |
| return Success(HandleIntToIntCast(DestType, SrcType, |
| Result.getInt(), Info.Ctx), E); |
| } |
| |
| // FIXME: Clean this up! |
| if (SrcType->isPointerType()) { |
| LValue LV; |
| if (!EvaluatePointer(SubExpr, LV, Info)) |
| return false; |
| |
| if (LV.getLValueBase()) { |
| // Only allow based lvalue casts if they are lossless. |
| if (Info.Ctx.getTypeSize(DestType) != Info.Ctx.getTypeSize(SrcType)) |
| return false; |
| |
| LV.moveInto(Result); |
| return true; |
| } |
| |
| APSInt AsInt = Info.Ctx.MakeIntValue(LV.getLValueOffset().getQuantity(), |
| SrcType); |
| return Success(HandleIntToIntCast(DestType, SrcType, AsInt, Info.Ctx), E); |
| } |
| |
| if (SrcType->isArrayType() || SrcType->isFunctionType()) { |
| // This handles double-conversion cases, where there's both |
| // an l-value promotion and an implicit conversion to int. |
| LValue LV; |
| if (!EvaluateLValue(SubExpr, LV, Info)) |
| return false; |
| |
| if (Info.Ctx.getTypeSize(DestType) != Info.Ctx.getTypeSize(Info.Ctx.VoidPtrTy)) |
| return false; |
| |
| LV.moveInto(Result); |
| return true; |
| } |
| |
| if (SrcType->isAnyComplexType()) { |
| ComplexValue C; |
| if (!EvaluateComplex(SubExpr, C, Info)) |
| return false; |
| if (C.isComplexFloat()) |
| return Success(HandleFloatToIntCast(DestType, SrcType, |
| C.getComplexFloatReal(), Info.Ctx), |
| E); |
| else |
| return Success(HandleIntToIntCast(DestType, SrcType, |
| C.getComplexIntReal(), Info.Ctx), E); |
| } |
| // FIXME: Handle vectors |
| |
| if (!SrcType->isRealFloatingType()) |
| return Error(E->getExprLoc(), diag::note_invalid_subexpr_in_ice, E); |
| |
| APFloat F(0.0); |
| if (!EvaluateFloat(SubExpr, F, Info)) |
| return Error(E->getExprLoc(), diag::note_invalid_subexpr_in_ice, E); |
| |
| return Success(HandleFloatToIntCast(DestType, SrcType, F, Info.Ctx), E); |
| } |
| |
| bool IntExprEvaluator::VisitUnaryReal(const UnaryOperator *E) { |
| if (E->getSubExpr()->getType()->isAnyComplexType()) { |
| ComplexValue LV; |
| if (!EvaluateComplex(E->getSubExpr(), LV, Info) || !LV.isComplexInt()) |
| return Error(E->getExprLoc(), diag::note_invalid_subexpr_in_ice, E); |
| return Success(LV.getComplexIntReal(), E); |
| } |
| |
| return Visit(E->getSubExpr()); |
| } |
| |
| bool IntExprEvaluator::VisitUnaryImag(const UnaryOperator *E) { |
| if (E->getSubExpr()->getType()->isComplexIntegerType()) { |
| ComplexValue LV; |
| if (!EvaluateComplex(E->getSubExpr(), LV, Info) || !LV.isComplexInt()) |
| return Error(E->getExprLoc(), diag::note_invalid_subexpr_in_ice, E); |
| return Success(LV.getComplexIntImag(), E); |
| } |
| |
| if (!E->getSubExpr()->isEvaluatable(Info.Ctx)) |
| Info.EvalResult.HasSideEffects = true; |
| return Success(0, E); |
| } |
| |
| bool IntExprEvaluator::VisitCXXNoexceptExpr(const CXXNoexceptExpr *E) { |
| return Success(E->getValue(), E); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Float Evaluation |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class FloatExprEvaluator |
| : public StmtVisitor<FloatExprEvaluator, bool> { |
| EvalInfo &Info; |
| APFloat &Result; |
| public: |
| FloatExprEvaluator(EvalInfo &info, APFloat &result) |
| : Info(info), Result(result) {} |
| |
| bool VisitStmt(Stmt *S) { |
| return false; |
| } |
| |
| bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
| bool VisitCallExpr(const CallExpr *E); |
| |
| bool VisitUnaryOperator(const UnaryOperator *E); |
| bool VisitBinaryOperator(const BinaryOperator *E); |
| bool VisitFloatingLiteral(const FloatingLiteral *E); |
| bool VisitCastExpr(CastExpr *E); |
| bool VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E); |
| bool VisitConditionalOperator(ConditionalOperator *E); |
| |
| bool VisitChooseExpr(const ChooseExpr *E) |
| { return Visit(E->getChosenSubExpr(Info.Ctx)); } |
| bool VisitUnaryExtension(const UnaryOperator *E) |
| { return Visit(E->getSubExpr()); } |
| bool VisitUnaryReal(const UnaryOperator *E); |
| bool VisitUnaryImag(const UnaryOperator *E); |
| |
| bool VisitDeclRefExpr(const DeclRefExpr *E); |
| |
| // FIXME: Missing: array subscript of vector, member of vector, |
| // ImplicitValueInitExpr |
| }; |
| } // end anonymous namespace |
| |
| static bool EvaluateFloat(const Expr* E, APFloat& Result, EvalInfo &Info) { |
| assert(E->getType()->isRealFloatingType()); |
| return FloatExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E)); |
| } |
| |
| static bool TryEvaluateBuiltinNaN(ASTContext &Context, |
| QualType ResultTy, |
| const Expr *Arg, |
| bool SNaN, |
| llvm::APFloat &Result) { |
| const StringLiteral *S = dyn_cast<StringLiteral>(Arg->IgnoreParenCasts()); |
| if (!S) return false; |
| |
| const llvm::fltSemantics &Sem = Context.getFloatTypeSemantics(ResultTy); |
| |
| llvm::APInt fill; |
| |
| // Treat empty strings as if they were zero. |
| if (S->getString().empty()) |
| fill = llvm::APInt(32, 0); |
| else if (S->getString().getAsInteger(0, fill)) |
| return false; |
| |
| if (SNaN) |
| Result = llvm::APFloat::getSNaN(Sem, false, &fill); |
| else |
| Result = llvm::APFloat::getQNaN(Sem, false, &fill); |
| return true; |
| } |
| |
| bool FloatExprEvaluator::VisitCallExpr(const CallExpr *E) { |
| switch (E->isBuiltinCall(Info.Ctx)) { |
| default: return false; |
| case Builtin::BI__builtin_huge_val: |
| case Builtin::BI__builtin_huge_valf: |
| case Builtin::BI__builtin_huge_vall: |
| case Builtin::BI__builtin_inf: |
| case Builtin::BI__builtin_inff: |
| case Builtin::BI__builtin_infl: { |
| const llvm::fltSemantics &Sem = |
| Info.Ctx.getFloatTypeSemantics(E->getType()); |
| Result = llvm::APFloat::getInf(Sem); |
| return true; |
| } |
| |
| case Builtin::BI__builtin_nans: |
| case Builtin::BI__builtin_nansf: |
| case Builtin::BI__builtin_nansl: |
| return TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0), |
| true, Result); |
| |
| case Builtin::BI__builtin_nan: |
| case Builtin::BI__builtin_nanf: |
| case Builtin::BI__builtin_nanl: |
| // If this is __builtin_nan() turn this into a nan, otherwise we |
| // can't constant fold it. |
| return TryEvaluateBuiltinNaN(Info.Ctx, E->getType(), E->getArg(0), |
| false, Result); |
| |
| case Builtin::BI__builtin_fabs: |
| case Builtin::BI__builtin_fabsf: |
| case Builtin::BI__builtin_fabsl: |
| if (!EvaluateFloat(E->getArg(0), Result, Info)) |
| return false; |
| |
| if (Result.isNegative()) |
| Result.changeSign(); |
| return true; |
| |
| case Builtin::BI__builtin_copysign: |
| case Builtin::BI__builtin_copysignf: |
| case Builtin::BI__builtin_copysignl: { |
| APFloat RHS(0.); |
| if (!EvaluateFloat(E->getArg(0), Result, Info) || |
| !EvaluateFloat(E->getArg(1), RHS, Info)) |
| return false; |
| Result.copySign(RHS); |
| return true; |
| } |
| } |
| } |
| |
| bool FloatExprEvaluator::VisitDeclRefExpr(const DeclRefExpr *E) { |
| const Decl *D = E->getDecl(); |
| if (!isa<VarDecl>(D) || isa<ParmVarDecl>(D)) return false; |
| const VarDecl *VD = cast<VarDecl>(D); |
| |
| // Require the qualifiers to be const and not volatile. |
| CanQualType T = Info.Ctx.getCanonicalType(E->getType()); |
| if (!T.isConstQualified() || T.isVolatileQualified()) |
| return false; |
| |
| const Expr *Init = VD->getAnyInitializer(); |
| if (!Init) return false; |
| |
| if (APValue *V = VD->getEvaluatedValue()) { |
| if (V->isFloat()) { |
| Result = V->getFloat(); |
| return true; |
| } |
| return false; |
| } |
| |
| if (VD->isEvaluatingValue()) |
| return false; |
| |
| VD->setEvaluatingValue(); |
| |
| Expr::EvalResult InitResult; |
| if (Init->Evaluate(InitResult, Info.Ctx) && !InitResult.HasSideEffects && |
| InitResult.Val.isFloat()) { |
| // Cache the evaluated value in the variable declaration. |
| Result = InitResult.Val.getFloat(); |
| VD->setEvaluatedValue(InitResult.Val); |
| return true; |
| } |
| |
| VD->setEvaluatedValue(APValue()); |
| return false; |
| } |
| |
| bool FloatExprEvaluator::VisitUnaryReal(const UnaryOperator *E) { |
| if (E->getSubExpr()->getType()->isAnyComplexType()) { |
| ComplexValue CV; |
| if (!EvaluateComplex(E->getSubExpr(), CV, Info)) |
| return false; |
| Result = CV.FloatReal; |
| return true; |
| } |
| |
| return Visit(E->getSubExpr()); |
| } |
| |
| bool FloatExprEvaluator::VisitUnaryImag(const UnaryOperator *E) { |
| if (E->getSubExpr()->getType()->isAnyComplexType()) { |
| ComplexValue CV; |
| if (!EvaluateComplex(E->getSubExpr(), CV, Info)) |
| return false; |
| Result = CV.FloatImag; |
| return true; |
| } |
| |
| if (!E->getSubExpr()->isEvaluatable(Info.Ctx)) |
| Info.EvalResult.HasSideEffects = true; |
| const llvm::fltSemantics &Sem = Info.Ctx.getFloatTypeSemantics(E->getType()); |
| Result = llvm::APFloat::getZero(Sem); |
| return true; |
| } |
| |
| bool FloatExprEvaluator::VisitUnaryOperator(const UnaryOperator *E) { |
| if (E->getOpcode() == UO_Deref) |
| return false; |
| |
| if (!EvaluateFloat(E->getSubExpr(), Result, Info)) |
| return false; |
| |
| switch (E->getOpcode()) { |
| default: return false; |
| case UO_Plus: |
| return true; |
| case UO_Minus: |
| Result.changeSign(); |
| return true; |
| } |
| } |
| |
| bool FloatExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { |
| if (E->getOpcode() == BO_Comma) { |
| if (!EvaluateFloat(E->getRHS(), Result, Info)) |
| return false; |
| |
| // If we can't evaluate the LHS, it might have side effects; |
| // conservatively mark it. |
| if (!E->getLHS()->isEvaluatable(Info.Ctx)) |
| Info.EvalResult.HasSideEffects = true; |
| |
| return true; |
| } |
| |
| // FIXME: Diagnostics? I really don't understand how the warnings |
| // and errors are supposed to work. |
| APFloat RHS(0.0); |
| if (!EvaluateFloat(E->getLHS(), Result, Info)) |
| return false; |
| if (!EvaluateFloat(E->getRHS(), RHS, Info)) |
| return false; |
| |
| switch (E->getOpcode()) { |
| default: return false; |
| case BO_Mul: |
| Result.multiply(RHS, APFloat::rmNearestTiesToEven); |
| return true; |
| case BO_Add: |
| Result.add(RHS, APFloat::rmNearestTiesToEven); |
| return true; |
| case BO_Sub: |
| Result.subtract(RHS, APFloat::rmNearestTiesToEven); |
| return true; |
| case BO_Div: |
| Result.divide(RHS, APFloat::rmNearestTiesToEven); |
| return true; |
| } |
| } |
| |
| bool FloatExprEvaluator::VisitFloatingLiteral(const FloatingLiteral *E) { |
| Result = E->getValue(); |
| return true; |
| } |
| |
| bool FloatExprEvaluator::VisitCastExpr(CastExpr *E) { |
| Expr* SubExpr = E->getSubExpr(); |
| |
| if (SubExpr->getType()->isIntegralOrEnumerationType()) { |
| APSInt IntResult; |
| if (!EvaluateInteger(SubExpr, IntResult, Info)) |
| return false; |
| Result = HandleIntToFloatCast(E->getType(), SubExpr->getType(), |
| IntResult, Info.Ctx); |
| return true; |
| } |
| if (SubExpr->getType()->isRealFloatingType()) { |
| if (!Visit(SubExpr)) |
| return false; |
| Result = HandleFloatToFloatCast(E->getType(), SubExpr->getType(), |
| Result, Info.Ctx); |
| return true; |
| } |
| // FIXME: Handle complex types |
| |
| return false; |
| } |
| |
| bool FloatExprEvaluator::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) { |
| Result = APFloat::getZero(Info.Ctx.getFloatTypeSemantics(E->getType())); |
| return true; |
| } |
| |
| bool FloatExprEvaluator::VisitConditionalOperator(ConditionalOperator *E) { |
| bool Cond; |
| if (!HandleConversionToBool(E->getCond(), Cond, Info)) |
| return false; |
| |
| return Visit(Cond ? E->getTrueExpr() : E->getFalseExpr()); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Complex Evaluation (for float and integer) |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| class ComplexExprEvaluator |
| : public StmtVisitor<ComplexExprEvaluator, bool> { |
| EvalInfo &Info; |
| ComplexValue &Result; |
| |
| public: |
| ComplexExprEvaluator(EvalInfo &info, ComplexValue &Result) |
| : Info(info), Result(Result) {} |
| |
| //===--------------------------------------------------------------------===// |
| // Visitor Methods |
| //===--------------------------------------------------------------------===// |
| |
| bool VisitStmt(Stmt *S) { |
| return false; |
| } |
| |
| bool VisitParenExpr(ParenExpr *E) { return Visit(E->getSubExpr()); } |
| |
| bool VisitImaginaryLiteral(ImaginaryLiteral *E); |
| |
| bool VisitCastExpr(CastExpr *E); |
| |
| bool VisitBinaryOperator(const BinaryOperator *E); |
| bool VisitChooseExpr(const ChooseExpr *E) |
| { return Visit(E->getChosenSubExpr(Info.Ctx)); } |
| bool VisitUnaryExtension(const UnaryOperator *E) |
| { return Visit(E->getSubExpr()); } |
| // FIXME Missing: unary +/-/~, binary div, ImplicitValueInitExpr, |
| // conditional ?:, comma |
| }; |
| } // end anonymous namespace |
| |
| static bool EvaluateComplex(const Expr *E, ComplexValue &Result, |
| EvalInfo &Info) { |
| assert(E->getType()->isAnyComplexType()); |
| return ComplexExprEvaluator(Info, Result).Visit(const_cast<Expr*>(E)); |
| } |
| |
| bool ComplexExprEvaluator::VisitImaginaryLiteral(ImaginaryLiteral *E) { |
| Expr* SubExpr = E->getSubExpr(); |
| |
| if (SubExpr->getType()->isRealFloatingType()) { |
| Result.makeComplexFloat(); |
| APFloat &Imag = Result.FloatImag; |
| if (!EvaluateFloat(SubExpr, Imag, Info)) |
| return false; |
| |
| Result.FloatReal = APFloat(Imag.getSemantics()); |
| return true; |
| } else { |
| assert(SubExpr->getType()->isIntegerType() && |
| "Unexpected imaginary literal."); |
| |
| Result.makeComplexInt(); |
| APSInt &Imag = Result.IntImag; |
| if (!EvaluateInteger(SubExpr, Imag, Info)) |
| return false; |
| |
| Result.IntReal = APSInt(Imag.getBitWidth(), !Imag.isSigned()); |
| return true; |
| } |
| } |
| |
| bool ComplexExprEvaluator::VisitCastExpr(CastExpr *E) { |
| Expr* SubExpr = E->getSubExpr(); |
| QualType EltType = E->getType()->getAs<ComplexType>()->getElementType(); |
| QualType SubType = SubExpr->getType(); |
| |
| if (SubType->isRealFloatingType()) { |
| APFloat &Real = Result.FloatReal; |
| if (!EvaluateFloat(SubExpr, Real, Info)) |
| return false; |
| |
| if (EltType->isRealFloatingType()) { |
| Result.makeComplexFloat(); |
| Real = HandleFloatToFloatCast(EltType, SubType, Real, Info.Ctx); |
| Result.FloatImag = APFloat(Real.getSemantics()); |
| return true; |
| } else { |
| Result.makeComplexInt(); |
| Result.IntReal = HandleFloatToIntCast(EltType, SubType, Real, Info.Ctx); |
| Result.IntImag = APSInt(Result.IntReal.getBitWidth(), |
| !Result.IntReal.isSigned()); |
| return true; |
| } |
| } else if (SubType->isIntegerType()) { |
| APSInt &Real = Result.IntReal; |
| if (!EvaluateInteger(SubExpr, Real, Info)) |
| return false; |
| |
| if (EltType->isRealFloatingType()) { |
| Result.makeComplexFloat(); |
| Result.FloatReal |
| = HandleIntToFloatCast(EltType, SubType, Real, Info.Ctx); |
| Result.FloatImag = APFloat(Result.FloatReal.getSemantics()); |
| return true; |
| } else { |
| Result.makeComplexInt(); |
| Real = HandleIntToIntCast(EltType, SubType, Real, Info.Ctx); |
| Result.IntImag = APSInt(Real.getBitWidth(), !Real.isSigned()); |
| return true; |
| } |
| } else if (const ComplexType *CT = SubType->getAs<ComplexType>()) { |
| if (!Visit(SubExpr)) |
| return false; |
| |
| QualType SrcType = CT->getElementType(); |
| |
| if (Result.isComplexFloat()) { |
| if (EltType->isRealFloatingType()) { |
| Result.makeComplexFloat(); |
| Result.FloatReal = HandleFloatToFloatCast(EltType, SrcType, |
| Result.FloatReal, |
| Info.Ctx); |
| Result.FloatImag = HandleFloatToFloatCast(EltType, SrcType, |
| Result.FloatImag, |
| Info.Ctx); |
| return true; |
| } else { |
| Result.makeComplexInt(); |
| Result.IntReal = HandleFloatToIntCast(EltType, SrcType, |
| Result.FloatReal, |
| Info.Ctx); |
| Result.IntImag = HandleFloatToIntCast(EltType, SrcType, |
| Result.FloatImag, |
| Info.Ctx); |
| return true; |
| } |
| } else { |
| assert(Result.isComplexInt() && "Invalid evaluate result."); |
| if (EltType->isRealFloatingType()) { |
| Result.makeComplexFloat(); |
| Result.FloatReal = HandleIntToFloatCast(EltType, SrcType, |
| Result.IntReal, |
| Info.Ctx); |
| Result.FloatImag = HandleIntToFloatCast(EltType, SrcType, |
| Result.IntImag, |
| Info.Ctx); |
| return true; |
| } else { |
| Result.makeComplexInt(); |
| Result.IntReal = HandleIntToIntCast(EltType, SrcType, |
| Result.IntReal, |
| Info.Ctx); |
| Result.IntImag = HandleIntToIntCast(EltType, SrcType, |
| Result.IntImag, |
| Info.Ctx); |
| return true; |
| } |
| } |
| } |
| |
| // FIXME: Handle more casts. |
| return false; |
| } |
| |
| bool ComplexExprEvaluator::VisitBinaryOperator(const BinaryOperator *E) { |
| if (!Visit(E->getLHS())) |
| return false; |
| |
| ComplexValue RHS; |
| if (!EvaluateComplex(E->getRHS(), RHS, Info)) |
| return false; |
| |
| assert(Result.isComplexFloat() == RHS.isComplexFloat() && |
| "Invalid operands to binary operator."); |
| switch (E->getOpcode()) { |
| default: return false; |
| case BO_Add: |
| if (Result.isComplexFloat()) { |
| Result.getComplexFloatReal().add(RHS.getComplexFloatReal(), |
| APFloat::rmNearestTiesToEven); |
| Result.getComplexFloatImag().add(RHS.getComplexFloatImag(), |
| APFloat::rmNearestTiesToEven); |
| } else { |
| Result.getComplexIntReal() += RHS.getComplexIntReal(); |
| Result.getComplexIntImag() += RHS.getComplexIntImag(); |
| } |
| break; |
| case BO_Sub: |
| if (Result.isComplexFloat()) { |
| Result.getComplexFloatReal().subtract(RHS.getComplexFloatReal(), |
| APFloat::rmNearestTiesToEven); |
| Result.getComplexFloatImag().subtract(RHS.getComplexFloatImag(), |
| APFloat::rmNearestTiesToEven); |
| } else { |
| Result.getComplexIntReal() -= RHS.getComplexIntReal(); |
| Result.getComplexIntImag() -= RHS.getComplexIntImag(); |
| } |
| break; |
| case BO_Mul: |
| if (Result.isComplexFloat()) { |
| ComplexValue LHS = Result; |
| APFloat &LHS_r = LHS.getComplexFloatReal(); |
| APFloat &LHS_i = LHS.getComplexFloatImag(); |
| APFloat &RHS_r = RHS.getComplexFloatReal(); |
| APFloat &RHS_i = RHS.getComplexFloatImag(); |
| |
| APFloat Tmp = LHS_r; |
| Tmp.multiply(RHS_r, APFloat::rmNearestTiesToEven); |
| Result.getComplexFloatReal() = Tmp; |
| Tmp = LHS_i; |
| Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven); |
| Result.getComplexFloatReal().subtract(Tmp, APFloat::rmNearestTiesToEven); |
| |
| Tmp = LHS_r; |
| Tmp.multiply(RHS_i, APFloat::rmNearestTiesToEven); |
| Result.getComplexFloatImag() = Tmp; |
| Tmp = LHS_i; |
| Tmp.multiply(RHS_r, APFloat::rmNearestTiesToEven); |
| Result.getComplexFloatImag().add(Tmp, APFloat::rmNearestTiesToEven); |
| } else { |
| ComplexValue LHS = Result; |
| Result.getComplexIntReal() = |
| (LHS.getComplexIntReal() * RHS.getComplexIntReal() - |
| LHS.getComplexIntImag() * RHS.getComplexIntImag()); |
| Result.getComplexIntImag() = |
| (LHS.getComplexIntReal() * RHS.getComplexIntImag() + |
| LHS.getComplexIntImag() * RHS.getComplexIntReal()); |
| } |
| break; |
| } |
| |
| return true; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Top level Expr::Evaluate method. |
| //===----------------------------------------------------------------------===// |
| |
| /// Evaluate - Return true if this is a constant which we can fold using |
| /// any crazy technique (that has nothing to do with language standards) that |
| /// we want to. If this function returns true, it returns the folded constant |
| /// in Result. |
| bool Expr::Evaluate(EvalResult &Result, ASTContext &Ctx) const { |
| const Expr *E = this; |
| EvalInfo Info(Ctx, Result); |
| if (E->getType()->isVectorType()) { |
| if (!EvaluateVector(E, Info.EvalResult.Val, Info)) |
| return false; |
| } else if (E->getType()->isIntegerType()) { |
| if (!IntExprEvaluator(Info, Info.EvalResult.Val).Visit(const_cast<Expr*>(E))) |
| return false; |
| if (Result.Val.isLValue() && !IsGlobalLValue(Result.Val.getLValueBase())) |
| return false; |
| } else if (E->getType()->hasPointerRepresentation()) { |
| LValue LV; |
| if (!EvaluatePointer(E, LV, Info)) |
| return false; |
| if (!IsGlobalLValue(LV.Base)) |
| return false; |
| LV.moveInto(Info.EvalResult.Val); |
| } else if (E->getType()->isRealFloatingType()) { |
| llvm::APFloat F(0.0); |
| if (!EvaluateFloat(E, F, Info)) |
| return false; |
| |
| Info.EvalResult.Val = APValue(F); |
| } else if (E->getType()->isAnyComplexType()) { |
| ComplexValue C; |
| if (!EvaluateComplex(E, C, Info)) |
| return false; |
| C.moveInto(Info.EvalResult.Val); |
| } else |
| return false; |
| |
| return true; |
| } |
| |
| bool Expr::EvaluateAsBooleanCondition(bool &Result, ASTContext &Ctx) const { |
| EvalResult Scratch; |
| EvalInfo Info(Ctx, Scratch); |
| |
| return HandleConversionToBool(this, Result, Info); |
| } |
| |
| bool Expr::EvaluateAsLValue(EvalResult &Result, ASTContext &Ctx) const { |
| EvalInfo Info(Ctx, Result); |
| |
| LValue LV; |
| if (EvaluateLValue(this, LV, Info) && |
| !Result.HasSideEffects && |
| IsGlobalLValue(LV.Base)) { |
| LV.moveInto(Result.Val); |
| return true; |
| } |
| return false; |
| } |
| |
| bool Expr::EvaluateAsAnyLValue(EvalResult &Result, ASTContext &Ctx) const { |
| EvalInfo Info(Ctx, Result); |
| |
| LValue LV; |
| if (EvaluateLValue(this, LV, Info)) { |
| LV.moveInto(Result.Val); |
| return true; |
| } |
| return false; |
| } |
| |
| /// isEvaluatable - Call Evaluate to see if this expression can be constant |
| /// folded, but discard the result. |
| bool Expr::isEvaluatable(ASTContext &Ctx) const { |
| EvalResult Result; |
| return Evaluate(Result, Ctx) && !Result.HasSideEffects; |
| } |
| |
| bool Expr::HasSideEffects(ASTContext &Ctx) const { |
| Expr::EvalResult Result; |
| EvalInfo Info(Ctx, Result); |
| return HasSideEffect(Info).Visit(const_cast<Expr*>(this)); |
| } |
| |
| APSInt Expr::EvaluateAsInt(ASTContext &Ctx) const { |
| EvalResult EvalResult; |
| bool Result = Evaluate(EvalResult, Ctx); |
| Result = Result; |
| assert(Result && "Could not evaluate expression"); |
| assert(EvalResult.Val.isInt() && "Expression did not evaluate to integer"); |
| |
| return EvalResult.Val.getInt(); |
| } |
| |
| bool Expr::EvalResult::isGlobalLValue() const { |
| assert(Val.isLValue()); |
| return IsGlobalLValue(Val.getLValueBase()); |
| } |
| |
| |
| /// isIntegerConstantExpr - this recursive routine will test if an expression is |
| /// an integer constant expression. |
| |
| /// FIXME: Pass up a reason why! Invalid operation in i-c-e, division by zero, |
| /// comma, etc |
| /// |
| /// FIXME: Handle offsetof. Two things to do: Handle GCC's __builtin_offsetof |
| /// to support gcc 4.0+ and handle the idiom GCC recognizes with a null pointer |
| /// cast+dereference. |
| |
| // CheckICE - This function does the fundamental ICE checking: the returned |
| // ICEDiag contains a Val of 0, 1, or 2, and a possibly null SourceLocation. |
| // Note that to reduce code duplication, this helper does no evaluation |
| // itself; the caller checks whether the expression is evaluatable, and |
| // in the rare cases where CheckICE actually cares about the evaluated |
| // value, it calls into Evalute. |
| // |
| // Meanings of Val: |
| // 0: This expression is an ICE if it can be evaluated by Evaluate. |
| // 1: This expression is not an ICE, but if it isn't evaluated, it's |
| // a legal subexpression for an ICE. This return value is used to handle |
| // the comma operator in C99 mode. |
| // 2: This expression is not an ICE, and is not a legal subexpression for one. |
| |
| namespace { |
| |
| struct ICEDiag { |
| unsigned Val; |
| SourceLocation Loc; |
| |
| public: |
| ICEDiag(unsigned v, SourceLocation l) : Val(v), Loc(l) {} |
| ICEDiag() : Val(0) {} |
| }; |
| |
| } |
| |
| static ICEDiag NoDiag() { return ICEDiag(); } |
| |
| static ICEDiag CheckEvalInICE(const Expr* E, ASTContext &Ctx) { |
| Expr::EvalResult EVResult; |
| if (!E->Evaluate(EVResult, Ctx) || EVResult.HasSideEffects || |
| !EVResult.Val.isInt()) { |
| return ICEDiag(2, E->getLocStart()); |
| } |
| return NoDiag(); |
| } |
| |
| static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) { |
| assert(!E->isValueDependent() && "Should not see value dependent exprs!"); |
| if (!E->getType()->isIntegralOrEnumerationType()) { |
| return ICEDiag(2, E->getLocStart()); |
| } |
| |
| switch (E->getStmtClass()) { |
| #define STMT(Node, Base) case Expr::Node##Class: |
| #define EXPR(Node, Base) |
| #include "clang/AST/StmtNodes.inc" |
| case Expr::PredefinedExprClass: |
| case Expr::FloatingLiteralClass: |
| case Expr::ImaginaryLiteralClass: |
| case Expr::StringLiteralClass: |
| case Expr::ArraySubscriptExprClass: |
| case Expr::MemberExprClass: |
| case Expr::CompoundAssignOperatorClass: |
| case Expr::CompoundLiteralExprClass: |
| case Expr::ExtVectorElementExprClass: |
| case Expr::InitListExprClass: |
| case Expr::DesignatedInitExprClass: |
| case Expr::ImplicitValueInitExprClass: |
| case Expr::ParenListExprClass: |
| case Expr::VAArgExprClass: |
| case Expr::AddrLabelExprClass: |
| case Expr::StmtExprClass: |
| case Expr::CXXMemberCallExprClass: |
| case Expr::CXXDynamicCastExprClass: |
| case Expr::CXXTypeidExprClass: |
| case Expr::CXXUuidofExprClass: |
| case Expr::CXXNullPtrLiteralExprClass: |
| case Expr::CXXThisExprClass: |
| case Expr::CXXThrowExprClass: |
| case Expr::CXXNewExprClass: |
| case Expr::CXXDeleteExprClass: |
| case Expr::CXXPseudoDestructorExprClass: |
| case Expr::UnresolvedLookupExprClass: |
| case Expr::DependentScopeDeclRefExprClass: |
| case Expr::CXXConstructExprClass: |
| case Expr::CXXBindTemporaryExprClass: |
| case Expr::CXXExprWithTemporariesClass: |
| case Expr::CXXTemporaryObjectExprClass: |
| case Expr::CXXUnresolvedConstructExprClass: |
| case Expr::CXXDependentScopeMemberExprClass: |
| case Expr::UnresolvedMemberExprClass: |
| case Expr::ObjCStringLiteralClass: |
| case Expr::ObjCEncodeExprClass: |
| case Expr::ObjCMessageExprClass: |
| case Expr::ObjCSelectorExprClass: |
| case Expr::ObjCProtocolExprClass: |
| case Expr::ObjCIvarRefExprClass: |
| case Expr::ObjCPropertyRefExprClass: |
| case Expr::ObjCImplicitSetterGetterRefExprClass: |
| case Expr::ObjCIsaExprClass: |
| case Expr::ShuffleVectorExprClass: |
| case Expr::BlockExprClass: |
| case Expr::BlockDeclRefExprClass: |
| case Expr::NoStmtClass: |
| return ICEDiag(2, E->getLocStart()); |
| |
| case Expr::GNUNullExprClass: |
| // GCC considers the GNU __null value to be an integral constant expression. |
| return NoDiag(); |
| |
| case Expr::ParenExprClass: |
| return CheckICE(cast<ParenExpr>(E)->getSubExpr(), Ctx); |
| case Expr::IntegerLiteralClass: |
| case Expr::CharacterLiteralClass: |
| case Expr::CXXBoolLiteralExprClass: |
| case Expr::CXXScalarValueInitExprClass: |
| case Expr::TypesCompatibleExprClass: |
| case Expr::UnaryTypeTraitExprClass: |
| case Expr::CXXNoexceptExprClass: |
| return NoDiag(); |
| case Expr::CallExprClass: |
| case Expr::CXXOperatorCallExprClass: { |
| const CallExpr *CE = cast<CallExpr>(E); |
| if (CE->isBuiltinCall(Ctx)) |
| return CheckEvalInICE(E, Ctx); |
| return ICEDiag(2, E->getLocStart()); |
| } |
| case Expr::DeclRefExprClass: |
| if (isa<EnumConstantDecl>(cast<DeclRefExpr>(E)->getDecl())) |
| return NoDiag(); |
| if (Ctx.getLangOptions().CPlusPlus && |
| E->getType().getCVRQualifiers() == Qualifiers::Const) { |
| const NamedDecl *D = cast<DeclRefExpr>(E)->getDecl(); |
| |
| // Parameter variables are never constants. Without this check, |
| // getAnyInitializer() can find a default argument, which leads |
| // to chaos. |
| if (isa<ParmVarDecl>(D)) |
| return ICEDiag(2, cast<DeclRefExpr>(E)->getLocation()); |
| |
| // C++ 7.1.5.1p2 |
| // A variable of non-volatile const-qualified integral or enumeration |
| // type initialized by an ICE can be used in ICEs. |
| if (const VarDecl *Dcl = dyn_cast<VarDecl>(D)) { |
| Qualifiers Quals = Ctx.getCanonicalType(Dcl->getType()).getQualifiers(); |
| if (Quals.hasVolatile() || !Quals.hasConst()) |
| return ICEDiag(2, cast<DeclRefExpr>(E)->getLocation()); |
| |
| // Look for a declaration of this variable that has an initializer. |
| const VarDecl *ID = 0; |
| const Expr *Init = Dcl->getAnyInitializer(ID); |
| if (Init) { |
| if (ID->isInitKnownICE()) { |
| // We have already checked whether this subexpression is an |
| // integral constant expression. |
| if (ID->isInitICE()) |
| return NoDiag(); |
| else |
| return ICEDiag(2, cast<DeclRefExpr>(E)->getLocation()); |
| } |
| |
| // It's an ICE whether or not the definition we found is |
| // out-of-line. See DR 721 and the discussion in Clang PR |
| // 6206 for details. |
| |
| if (Dcl->isCheckingICE()) { |
| return ICEDiag(2, cast<DeclRefExpr>(E)->getLocation()); |
| } |
| |
| Dcl->setCheckingICE(); |
| ICEDiag Result = CheckICE(Init, Ctx); |
| // Cache the result of the ICE test. |
| Dcl->setInitKnownICE(Result.Val == 0); |
| return Result; |
| } |
| } |
| } |
| return ICEDiag(2, E->getLocStart()); |
| case Expr::UnaryOperatorClass: { |
| const UnaryOperator *Exp = cast<UnaryOperator>(E); |
| switch (Exp->getOpcode()) { |
| case UO_PostInc: |
| case UO_PostDec: |
| case UO_PreInc: |
| case UO_PreDec: |
| case UO_AddrOf: |
| case UO_Deref: |
| return ICEDiag(2, E->getLocStart()); |
| case UO_Extension: |
| case UO_LNot: |
| case UO_Plus: |
| case UO_Minus: |
| case UO_Not: |
| case UO_Real: |
| case UO_Imag: |
| return CheckICE(Exp->getSubExpr(), Ctx); |
| } |
| |
| // OffsetOf falls through here. |
| } |
| case Expr::OffsetOfExprClass: { |
| // Note that per C99, offsetof must be an ICE. And AFAIK, using |
| // Evaluate matches the proposed gcc behavior for cases like |
| // "offsetof(struct s{int x[4];}, x[!.0])". This doesn't affect |
| // compliance: we should warn earlier for offsetof expressions with |
| // array subscripts that aren't ICEs, and if the array subscripts |
| // are ICEs, the value of the offsetof must be an integer constant. |
| return CheckEvalInICE(E, Ctx); |
| } |
| case Expr::SizeOfAlignOfExprClass: { |
| const SizeOfAlignOfExpr *Exp = cast<SizeOfAlignOfExpr>(E); |
| if (Exp->isSizeOf() && Exp->getTypeOfArgument()->isVariableArrayType()) |
| return ICEDiag(2, E->getLocStart()); |
| return NoDiag(); |
| } |
| case Expr::BinaryOperatorClass: { |
| const BinaryOperator *Exp = cast<BinaryOperator>(E); |
| switch (Exp->getOpcode()) { |
| case BO_PtrMemD: |
| case BO_PtrMemI: |
| case BO_Assign: |
| case BO_MulAssign: |
| case BO_DivAssign: |
| case BO_RemAssign: |
| case BO_AddAssign: |
| case BO_SubAssign: |
| case BO_ShlAssign: |
| case BO_ShrAssign: |
| case BO_AndAssign: |
| case BO_XorAssign: |
| case BO_OrAssign: |
| return ICEDiag(2, E->getLocStart()); |
| |
| case BO_Mul: |
| case BO_Div: |
| case BO_Rem: |
| case BO_Add: |
| case BO_Sub: |
| case BO_Shl: |
| case BO_Shr: |
| case BO_LT: |
| case BO_GT: |
| case BO_LE: |
| case BO_GE: |
| case BO_EQ: |
| case BO_NE: |
| case BO_And: |
| case BO_Xor: |
| case BO_Or: |
| case BO_Comma: { |
| ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx); |
| ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx); |
| if (Exp->getOpcode() == BO_Div || |
| Exp->getOpcode() == BO_Rem) { |
| // Evaluate gives an error for undefined Div/Rem, so make sure |
| // we don't evaluate one. |
| if (LHSResult.Val != 2 && RHSResult.Val != 2) { |
| llvm::APSInt REval = Exp->getRHS()->EvaluateAsInt(Ctx); |
| if (REval == 0) |
| return ICEDiag(1, E->getLocStart()); |
| if (REval.isSigned() && REval.isAllOnesValue()) { |
| llvm::APSInt LEval = Exp->getLHS()->EvaluateAsInt(Ctx); |
| if (LEval.isMinSignedValue()) |
| return ICEDiag(1, E->getLocStart()); |
| } |
| } |
| } |
| if (Exp->getOpcode() == BO_Comma) { |
| if (Ctx.getLangOptions().C99) { |
| // C99 6.6p3 introduces a strange edge case: comma can be in an ICE |
| // if it isn't evaluated. |
| if (LHSResult.Val == 0 && RHSResult.Val == 0) |
| return ICEDiag(1, E->getLocStart()); |
| } else { |
| // In both C89 and C++, commas in ICEs are illegal. |
| return ICEDiag(2, E->getLocStart()); |
| } |
| } |
| if (LHSResult.Val >= RHSResult.Val) |
| return LHSResult; |
| return RHSResult; |
| } |
| case BO_LAnd: |
| case BO_LOr: { |
| ICEDiag LHSResult = CheckICE(Exp->getLHS(), Ctx); |
| ICEDiag RHSResult = CheckICE(Exp->getRHS(), Ctx); |
| if (LHSResult.Val == 0 && RHSResult.Val == 1) { |
| // Rare case where the RHS has a comma "side-effect"; we need |
| // to actually check the condition to see whether the side |
| // with the comma is evaluated. |
| if ((Exp->getOpcode() == BO_LAnd) != |
| (Exp->getLHS()->EvaluateAsInt(Ctx) == 0)) |
| return RHSResult; |
| return NoDiag(); |
| } |
| |
| if (LHSResult.Val >= RHSResult.Val) |
| return LHSResult; |
| return RHSResult; |
| } |
| } |
| } |
| case Expr::ImplicitCastExprClass: |
| case Expr::CStyleCastExprClass: |
| case Expr::CXXFunctionalCastExprClass: |
| case Expr::CXXStaticCastExprClass: |
| case Expr::CXXReinterpretCastExprClass: |
| case Expr::CXXConstCastExprClass: { |
| const Expr *SubExpr = cast<CastExpr>(E)->getSubExpr(); |
| if (SubExpr->getType()->isIntegralOrEnumerationType()) |
| return CheckICE(SubExpr, Ctx); |
| if (isa<FloatingLiteral>(SubExpr->IgnoreParens())) |
| return NoDiag(); |
| return ICEDiag(2, E->getLocStart()); |
| } |
| case Expr::ConditionalOperatorClass: { |
| const ConditionalOperator *Exp = cast<ConditionalOperator>(E); |
| // If the condition (ignoring parens) is a __builtin_constant_p call, |
| // then only the true side is actually considered in an integer constant |
| // expression, and it is fully evaluated. This is an important GNU |
| // extension. See GCC PR38377 for discussion. |
| if (const CallExpr *CallCE |
| = dyn_cast<CallExpr>(Exp->getCond()->IgnoreParenCasts())) |
| if (CallCE->isBuiltinCall(Ctx) == Builtin::BI__builtin_constant_p) { |
| Expr::EvalResult EVResult; |
| if (!E->Evaluate(EVResult, Ctx) || EVResult.HasSideEffects || |
| !EVResult.Val.isInt()) { |
| return ICEDiag(2, E->getLocStart()); |
| } |
| return NoDiag(); |
| } |
| ICEDiag CondResult = CheckICE(Exp->getCond(), Ctx); |
| ICEDiag TrueResult = CheckICE(Exp->getTrueExpr(), Ctx); |
| ICEDiag FalseResult = CheckICE(Exp->getFalseExpr(), Ctx); |
| if (CondResult.Val == 2) |
| return CondResult; |
| if (TrueResult.Val == 2) |
| return TrueResult; |
| if (FalseResult.Val == 2) |
| return FalseResult; |
| if (CondResult.Val == 1) |
| return CondResult; |
| if (TrueResult.Val == 0 && FalseResult.Val == 0) |
| return NoDiag(); |
| // Rare case where the diagnostics depend on which side is evaluated |
| // Note that if we get here, CondResult is 0, and at least one of |
| // TrueResult and FalseResult is non-zero. |
| if (Exp->getCond()->EvaluateAsInt(Ctx) == 0) { |
| return FalseResult; |
| } |
| return TrueResult; |
| } |
| case Expr::CXXDefaultArgExprClass: |
| return CheckICE(cast<CXXDefaultArgExpr>(E)->getExpr(), Ctx); |
| case Expr::ChooseExprClass: { |
| return CheckICE(cast<ChooseExpr>(E)->getChosenSubExpr(Ctx), Ctx); |
| } |
| } |
| |
| // Silence a GCC warning |
| return ICEDiag(2, E->getLocStart()); |
| } |
| |
| bool Expr::isIntegerConstantExpr(llvm::APSInt &Result, ASTContext &Ctx, |
| SourceLocation *Loc, bool isEvaluated) const { |
| ICEDiag d = CheckICE(this, Ctx); |
| if (d.Val != 0) { |
| if (Loc) *Loc = d.Loc; |
| return false; |
| } |
| EvalResult EvalResult; |
| if (!Evaluate(EvalResult, Ctx)) |
| llvm_unreachable("ICE cannot be evaluated!"); |
| assert(!EvalResult.HasSideEffects && "ICE with side effects!"); |
| assert(EvalResult.Val.isInt() && "ICE that isn't integer!"); |
| Result = EvalResult.Val.getInt(); |
| return true; |
| } |