diff options
Diffstat (limited to 'lib/CodeGen/CGExprConstant.cpp')
| -rw-r--r-- | lib/CodeGen/CGExprConstant.cpp | 1237 |
1 files changed, 848 insertions, 389 deletions
diff --git a/lib/CodeGen/CGExprConstant.cpp b/lib/CodeGen/CGExprConstant.cpp index 6b72774c10a59..d1b9e13a6f937 100644 --- a/lib/CodeGen/CGExprConstant.cpp +++ b/lib/CodeGen/CGExprConstant.cpp @@ -16,6 +16,7 @@ #include "CGObjCRuntime.h" #include "CGRecordLayout.h" #include "CodeGenModule.h" +#include "ConstantEmitter.h" #include "TargetInfo.h" #include "clang/AST/APValue.h" #include "clang/AST/ASTContext.h" @@ -37,25 +38,26 @@ namespace { class ConstExprEmitter; class ConstStructBuilder { CodeGenModule &CGM; - CodeGenFunction *CGF; + ConstantEmitter &Emitter; bool Packed; CharUnits NextFieldOffsetInChars; CharUnits LLVMStructAlignment; SmallVector<llvm::Constant *, 32> Elements; public: - static llvm::Constant *BuildStruct(CodeGenModule &CGM, CodeGenFunction *CFG, - ConstExprEmitter *Emitter, + static llvm::Constant *BuildStruct(ConstantEmitter &Emitter, + ConstExprEmitter *ExprEmitter, llvm::ConstantStruct *Base, - InitListExpr *Updater); - static llvm::Constant *BuildStruct(CodeGenModule &CGM, CodeGenFunction *CGF, - InitListExpr *ILE); - static llvm::Constant *BuildStruct(CodeGenModule &CGM, CodeGenFunction *CGF, + InitListExpr *Updater, + QualType ValTy); + static llvm::Constant *BuildStruct(ConstantEmitter &Emitter, + InitListExpr *ILE, QualType StructTy); + static llvm::Constant *BuildStruct(ConstantEmitter &Emitter, const APValue &Value, QualType ValTy); private: - ConstStructBuilder(CodeGenModule &CGM, CodeGenFunction *CGF) - : CGM(CGM), CGF(CGF), Packed(false), + ConstStructBuilder(ConstantEmitter &emitter) + : CGM(emitter.CGM), Emitter(emitter), Packed(false), NextFieldOffsetInChars(CharUnits::Zero()), LLVMStructAlignment(CharUnits::One()) { } @@ -76,7 +78,7 @@ private: bool Build(InitListExpr *ILE); bool Build(ConstExprEmitter *Emitter, llvm::ConstantStruct *Base, InitListExpr *Updater); - void Build(const APValue &Val, const RecordDecl *RD, bool IsPrimaryBase, + bool Build(const APValue &Val, const RecordDecl *RD, bool IsPrimaryBase, const CXXRecordDecl *VTableClass, CharUnits BaseOffset); llvm::Constant *Finalize(QualType Ty); @@ -391,10 +393,10 @@ bool ConstStructBuilder::Build(InitListExpr *ILE) { // we just use explicit null values for them. llvm::Constant *EltInit; if (ElementNo < ILE->getNumInits()) - EltInit = CGM.EmitConstantExpr(ILE->getInit(ElementNo++), - Field->getType(), CGF); + EltInit = Emitter.tryEmitPrivateForMemory(ILE->getInit(ElementNo++), + Field->getType()); else - EltInit = CGM.EmitNullConstant(Field->getType()); + EltInit = Emitter.emitNullForMemory(Field->getType()); if (!EltInit) return false; @@ -431,7 +433,7 @@ struct BaseInfo { }; } -void ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD, +bool ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD, bool IsPrimaryBase, const CXXRecordDecl *VTableClass, CharUnits Offset) { @@ -486,8 +488,9 @@ void ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD, const APValue &FieldValue = RD->isUnion() ? Val.getUnionValue() : Val.getStructField(FieldNo); llvm::Constant *EltInit = - CGM.EmitConstantValueForMemory(FieldValue, Field->getType(), CGF); - assert(EltInit && "EmitConstantValue can't fail"); + Emitter.tryEmitPrivateForMemory(FieldValue, Field->getType()); + if (!EltInit) + return false; if (!Field->isBitField()) { // Handle non-bitfield members. @@ -498,6 +501,8 @@ void ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD, cast<llvm::ConstantInt>(EltInit)); } } + + return true; } llvm::Constant *ConstStructBuilder::Finalize(QualType Ty) { @@ -559,37 +564,37 @@ llvm::Constant *ConstStructBuilder::Finalize(QualType Ty) { return Result; } -llvm::Constant *ConstStructBuilder::BuildStruct(CodeGenModule &CGM, - CodeGenFunction *CGF, - ConstExprEmitter *Emitter, +llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter, + ConstExprEmitter *ExprEmitter, llvm::ConstantStruct *Base, - InitListExpr *Updater) { - ConstStructBuilder Builder(CGM, CGF); - if (!Builder.Build(Emitter, Base, Updater)) + InitListExpr *Updater, + QualType ValTy) { + ConstStructBuilder Builder(Emitter); + if (!Builder.Build(ExprEmitter, Base, Updater)) return nullptr; - return Builder.Finalize(Updater->getType()); + return Builder.Finalize(ValTy); } -llvm::Constant *ConstStructBuilder::BuildStruct(CodeGenModule &CGM, - CodeGenFunction *CGF, - InitListExpr *ILE) { - ConstStructBuilder Builder(CGM, CGF); +llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter, + InitListExpr *ILE, + QualType ValTy) { + ConstStructBuilder Builder(Emitter); if (!Builder.Build(ILE)) return nullptr; - return Builder.Finalize(ILE->getType()); + return Builder.Finalize(ValTy); } -llvm::Constant *ConstStructBuilder::BuildStruct(CodeGenModule &CGM, - CodeGenFunction *CGF, +llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter, const APValue &Val, QualType ValTy) { - ConstStructBuilder Builder(CGM, CGF); + ConstStructBuilder Builder(Emitter); const RecordDecl *RD = ValTy->castAs<RecordType>()->getDecl(); const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD); - Builder.Build(Val, RD, false, CD, CharUnits::Zero()); + if (!Builder.Build(Val, RD, false, CD, CharUnits::Zero())) + return nullptr; return Builder.Finalize(ValTy); } @@ -599,57 +604,86 @@ llvm::Constant *ConstStructBuilder::BuildStruct(CodeGenModule &CGM, // ConstExprEmitter //===----------------------------------------------------------------------===// +static ConstantAddress tryEmitGlobalCompoundLiteral(CodeGenModule &CGM, + CodeGenFunction *CGF, + const CompoundLiteralExpr *E) { + CharUnits Align = CGM.getContext().getTypeAlignInChars(E->getType()); + if (llvm::GlobalVariable *Addr = + CGM.getAddrOfConstantCompoundLiteralIfEmitted(E)) + return ConstantAddress(Addr, Align); + + LangAS addressSpace = E->getType().getAddressSpace(); + + ConstantEmitter emitter(CGM, CGF); + llvm::Constant *C = emitter.tryEmitForInitializer(E->getInitializer(), + addressSpace, E->getType()); + if (!C) { + assert(!E->isFileScope() && + "file-scope compound literal did not have constant initializer!"); + return ConstantAddress::invalid(); + } + + auto GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), + CGM.isTypeConstant(E->getType(), true), + llvm::GlobalValue::InternalLinkage, + C, ".compoundliteral", nullptr, + llvm::GlobalVariable::NotThreadLocal, + CGM.getContext().getTargetAddressSpace(addressSpace)); + emitter.finalize(GV); + GV->setAlignment(Align.getQuantity()); + CGM.setAddrOfConstantCompoundLiteral(E, GV); + return ConstantAddress(GV, Align); +} + /// This class only needs to handle two cases: /// 1) Literals (this is used by APValue emission to emit literals). /// 2) Arrays, structs and unions (outside C++11 mode, we don't currently /// constant fold these types). class ConstExprEmitter : - public StmtVisitor<ConstExprEmitter, llvm::Constant*> { + public StmtVisitor<ConstExprEmitter, llvm::Constant*, QualType> { CodeGenModule &CGM; - CodeGenFunction *CGF; + ConstantEmitter &Emitter; llvm::LLVMContext &VMContext; public: - ConstExprEmitter(CodeGenModule &cgm, CodeGenFunction *cgf) - : CGM(cgm), CGF(cgf), VMContext(cgm.getLLVMContext()) { + ConstExprEmitter(ConstantEmitter &emitter) + : CGM(emitter.CGM), Emitter(emitter), VMContext(CGM.getLLVMContext()) { } //===--------------------------------------------------------------------===// // Visitor Methods //===--------------------------------------------------------------------===// - llvm::Constant *VisitStmt(Stmt *S) { + llvm::Constant *VisitStmt(Stmt *S, QualType T) { return nullptr; } - llvm::Constant *VisitParenExpr(ParenExpr *PE) { - return Visit(PE->getSubExpr()); + llvm::Constant *VisitParenExpr(ParenExpr *PE, QualType T) { + return Visit(PE->getSubExpr(), T); } llvm::Constant * - VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE) { - return Visit(PE->getReplacement()); + VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE, + QualType T) { + return Visit(PE->getReplacement(), T); } - llvm::Constant *VisitGenericSelectionExpr(GenericSelectionExpr *GE) { - return Visit(GE->getResultExpr()); + llvm::Constant *VisitGenericSelectionExpr(GenericSelectionExpr *GE, + QualType T) { + return Visit(GE->getResultExpr(), T); } - llvm::Constant *VisitChooseExpr(ChooseExpr *CE) { - return Visit(CE->getChosenSubExpr()); + llvm::Constant *VisitChooseExpr(ChooseExpr *CE, QualType T) { + return Visit(CE->getChosenSubExpr(), T); } - llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { - return Visit(E->getInitializer()); + llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E, QualType T) { + return Visit(E->getInitializer(), T); } - llvm::Constant *VisitCastExpr(CastExpr* E) { + llvm::Constant *VisitCastExpr(CastExpr *E, QualType destType) { if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E)) - CGM.EmitExplicitCastExprType(ECE, CGF); + CGM.EmitExplicitCastExprType(ECE, Emitter.CGF); Expr *subExpr = E->getSubExpr(); - llvm::Constant *C = CGM.EmitConstantExpr(subExpr, subExpr->getType(), CGF); - if (!C) return nullptr; - - llvm::Type *destType = ConvertType(E->getType()); switch (E->getCastKind()) { case CK_ToUnion: { @@ -657,14 +691,22 @@ public: assert(E->getType()->isUnionType() && "Destination type is not union type!"); + auto field = E->getTargetUnionField(); + + auto C = Emitter.tryEmitPrivateForMemory(subExpr, field->getType()); + if (!C) return nullptr; + + auto destTy = ConvertType(destType); + if (C->getType() == destTy) return C; + // Build a struct with the union sub-element as the first member, - // and padded to the appropriate size + // and padded to the appropriate size. SmallVector<llvm::Constant*, 2> Elts; SmallVector<llvm::Type*, 2> Types; Elts.push_back(C); Types.push_back(C->getType()); unsigned CurSize = CGM.getDataLayout().getTypeAllocSize(C->getType()); - unsigned TotalSize = CGM.getDataLayout().getTypeAllocSize(destType); + unsigned TotalSize = CGM.getDataLayout().getTypeAllocSize(destTy); assert(CurSize <= TotalSize && "Union size mismatch!"); if (unsigned NumPadBytes = TotalSize - CurSize) { @@ -676,20 +718,26 @@ public: Types.push_back(Ty); } - llvm::StructType* STy = - llvm::StructType::get(C->getType()->getContext(), Types, false); + llvm::StructType *STy = llvm::StructType::get(VMContext, Types, false); return llvm::ConstantStruct::get(STy, Elts); } - case CK_AddressSpaceConversion: - return llvm::ConstantExpr::getAddrSpaceCast(C, destType); + case CK_AddressSpaceConversion: { + auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType()); + if (!C) return nullptr; + LangAS destAS = E->getType()->getPointeeType().getAddressSpace(); + LangAS srcAS = subExpr->getType()->getPointeeType().getAddressSpace(); + llvm::Type *destTy = ConvertType(E->getType()); + return CGM.getTargetCodeGenInfo().performAddrSpaceCast(CGM, C, srcAS, + destAS, destTy); + } case CK_LValueToRValue: case CK_AtomicToNonAtomic: case CK_NonAtomicToAtomic: case CK_NoOp: case CK_ConstructorConversion: - return C; + return Visit(subExpr, destType); case CK_IntToOCLSampler: llvm_unreachable("global sampler variables are not generated"); @@ -701,8 +749,11 @@ public: case CK_ReinterpretMemberPointer: case CK_DerivedToBaseMemberPointer: - case CK_BaseToDerivedMemberPointer: + case CK_BaseToDerivedMemberPointer: { + auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType()); + if (!C) return nullptr; return CGM.getCXXABI().EmitMemberPointerConversion(E, C); + } // These will never be supported. case CK_ObjCObjectLValueCast: @@ -759,27 +810,28 @@ public: llvm_unreachable("Invalid CastKind"); } - llvm::Constant *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { - return Visit(DAE->getExpr()); + llvm::Constant *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE, QualType T) { + return Visit(DAE->getExpr(), T); } - llvm::Constant *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) { + llvm::Constant *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE, QualType T) { // No need for a DefaultInitExprScope: we don't handle 'this' in a // constant expression. - return Visit(DIE->getExpr()); + return Visit(DIE->getExpr(), T); } - llvm::Constant *VisitExprWithCleanups(ExprWithCleanups *E) { + llvm::Constant *VisitExprWithCleanups(ExprWithCleanups *E, QualType T) { if (!E->cleanupsHaveSideEffects()) - return Visit(E->getSubExpr()); + return Visit(E->getSubExpr(), T); return nullptr; } - llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E) { - return Visit(E->GetTemporaryExpr()); + llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E, + QualType T) { + return Visit(E->GetTemporaryExpr(), T); } - llvm::Constant *EmitArrayInitialization(InitListExpr *ILE) { + llvm::Constant *EmitArrayInitialization(InitListExpr *ILE, QualType T) { llvm::ArrayType *AType = cast<llvm::ArrayType>(ConvertType(ILE->getType())); llvm::Type *ElemTy = AType->getElementType(); @@ -790,13 +842,14 @@ public: // initialise any elements that have not been initialised explicitly unsigned NumInitableElts = std::min(NumInitElements, NumElements); + QualType EltType = CGM.getContext().getAsArrayType(T)->getElementType(); + // Initialize remaining array elements. - // FIXME: This doesn't handle member pointers correctly! llvm::Constant *fillC; if (Expr *filler = ILE->getArrayFiller()) - fillC = CGM.EmitConstantExpr(filler, filler->getType(), CGF); + fillC = Emitter.tryEmitAbstractForMemory(filler, EltType); else - fillC = llvm::Constant::getNullValue(ElemTy); + fillC = Emitter.emitNullForMemory(EltType); if (!fillC) return nullptr; @@ -805,13 +858,13 @@ public: return llvm::ConstantAggregateZero::get(AType); // Copy initializer elements. - std::vector<llvm::Constant*> Elts; + SmallVector<llvm::Constant*, 16> Elts; Elts.reserve(NumInitableElts + NumElements); bool RewriteType = false; for (unsigned i = 0; i < NumInitableElts; ++i) { Expr *Init = ILE->getInit(i); - llvm::Constant *C = CGM.EmitConstantExpr(Init, Init->getType(), CGF); + llvm::Constant *C = Emitter.tryEmitPrivateForMemory(Init, EltType); if (!C) return nullptr; RewriteType |= (C->getType() != ElemTy); @@ -835,33 +888,33 @@ public: return llvm::ConstantArray::get(AType, Elts); } - llvm::Constant *EmitRecordInitialization(InitListExpr *ILE) { - return ConstStructBuilder::BuildStruct(CGM, CGF, ILE); + llvm::Constant *EmitRecordInitialization(InitListExpr *ILE, QualType T) { + return ConstStructBuilder::BuildStruct(Emitter, ILE, T); } - llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E) { - return CGM.EmitNullConstant(E->getType()); + llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E, + QualType T) { + return CGM.EmitNullConstant(T); } - llvm::Constant *VisitInitListExpr(InitListExpr *ILE) { + llvm::Constant *VisitInitListExpr(InitListExpr *ILE, QualType T) { if (ILE->isTransparent()) - return Visit(ILE->getInit(0)); + return Visit(ILE->getInit(0), T); if (ILE->getType()->isArrayType()) - return EmitArrayInitialization(ILE); + return EmitArrayInitialization(ILE, T); if (ILE->getType()->isRecordType()) - return EmitRecordInitialization(ILE); + return EmitRecordInitialization(ILE, T); return nullptr; } llvm::Constant *EmitDesignatedInitUpdater(llvm::Constant *Base, - InitListExpr *Updater) { - QualType ExprType = Updater->getType(); - - if (ExprType->isArrayType()) { - llvm::ArrayType *AType = cast<llvm::ArrayType>(ConvertType(ExprType)); + InitListExpr *Updater, + QualType destType) { + if (auto destAT = CGM.getContext().getAsArrayType(destType)) { + llvm::ArrayType *AType = cast<llvm::ArrayType>(ConvertType(destType)); llvm::Type *ElemType = AType->getElementType(); unsigned NumInitElements = Updater->getNumInits(); @@ -870,12 +923,12 @@ public: std::vector<llvm::Constant *> Elts; Elts.reserve(NumElements); - if (llvm::ConstantDataArray *DataArray = - dyn_cast<llvm::ConstantDataArray>(Base)) + QualType destElemType = destAT->getElementType(); + + if (auto DataArray = dyn_cast<llvm::ConstantDataArray>(Base)) for (unsigned i = 0; i != NumElements; ++i) Elts.push_back(DataArray->getElementAsConstant(i)); - else if (llvm::ConstantArray *Array = - dyn_cast<llvm::ConstantArray>(Base)) + else if (auto Array = dyn_cast<llvm::ConstantArray>(Base)) for (unsigned i = 0; i != NumElements; ++i) Elts.push_back(Array->getOperand(i)); else @@ -884,7 +937,7 @@ public: llvm::Constant *fillC = nullptr; if (Expr *filler = Updater->getArrayFiller()) if (!isa<NoInitExpr>(filler)) - fillC = CGM.EmitConstantExpr(filler, filler->getType(), CGF); + fillC = Emitter.tryEmitAbstractForMemory(filler, destElemType); bool RewriteType = (fillC && fillC->getType() != ElemType); for (unsigned i = 0; i != NumElements; ++i) { @@ -897,9 +950,9 @@ public: else if (!Init || isa<NoInitExpr>(Init)) ; // Do nothing. else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init)) - Elts[i] = EmitDesignatedInitUpdater(Elts[i], ChildILE); + Elts[i] = EmitDesignatedInitUpdater(Elts[i], ChildILE, destElemType); else - Elts[i] = CGM.EmitConstantExpr(Init, Init->getType(), CGF); + Elts[i] = Emitter.tryEmitPrivateForMemory(Init, destElemType); if (!Elts[i]) return nullptr; @@ -919,25 +972,24 @@ public: return llvm::ConstantArray::get(AType, Elts); } - if (ExprType->isRecordType()) - return ConstStructBuilder::BuildStruct(CGM, CGF, this, - dyn_cast<llvm::ConstantStruct>(Base), Updater); + if (destType->isRecordType()) + return ConstStructBuilder::BuildStruct(Emitter, this, + dyn_cast<llvm::ConstantStruct>(Base), Updater, destType); return nullptr; } - llvm::Constant *VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E) { - return EmitDesignatedInitUpdater( - CGM.EmitConstantExpr(E->getBase(), E->getType(), CGF), - E->getUpdater()); + llvm::Constant *VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E, + QualType destType) { + auto C = Visit(E->getBase(), destType); + if (!C) return nullptr; + return EmitDesignatedInitUpdater(C, E->getUpdater(), destType); } - llvm::Constant *VisitCXXConstructExpr(CXXConstructExpr *E) { + llvm::Constant *VisitCXXConstructExpr(CXXConstructExpr *E, QualType Ty) { if (!E->getConstructor()->isTrivial()) return nullptr; - QualType Ty = E->getType(); - // FIXME: We should not have to call getBaseElementType here. const RecordType *RT = CGM.getContext().getBaseElementType(Ty)->getAs<RecordType>(); @@ -960,26 +1012,23 @@ public: assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && "argument to copy ctor is of wrong type"); - return Visit(Arg); + return Visit(Arg, Ty); } return CGM.EmitNullConstant(Ty); } - llvm::Constant *VisitStringLiteral(StringLiteral *E) { + llvm::Constant *VisitStringLiteral(StringLiteral *E, QualType T) { return CGM.GetConstantArrayFromStringLiteral(E); } - llvm::Constant *VisitObjCEncodeExpr(ObjCEncodeExpr *E) { + llvm::Constant *VisitObjCEncodeExpr(ObjCEncodeExpr *E, QualType T) { // This must be an @encode initializing an array in a static initializer. // Don't emit it as the address of the string, emit the string data itself // as an inline array. std::string Str; CGM.getContext().getObjCEncodingForType(E->getEncodedType(), Str); - QualType T = E->getType(); - if (T->getTypeClass() == Type::TypeOfExpr) - T = cast<TypeOfExprType>(T)->getUnderlyingExpr()->getType(); - const ConstantArrayType *CAT = cast<ConstantArrayType>(T); + const ConstantArrayType *CAT = CGM.getContext().getAsConstantArrayType(T); // Resize the string to the right size, adding zeros at the end, or // truncating as needed. @@ -987,151 +1036,19 @@ public: return llvm::ConstantDataArray::getString(VMContext, Str, false); } - llvm::Constant *VisitUnaryExtension(const UnaryOperator *E) { - return Visit(E->getSubExpr()); + llvm::Constant *VisitUnaryExtension(const UnaryOperator *E, QualType T) { + return Visit(E->getSubExpr(), T); } // Utility methods llvm::Type *ConvertType(QualType T) { return CGM.getTypes().ConvertType(T); } - -public: - ConstantAddress EmitLValue(APValue::LValueBase LVBase) { - if (const ValueDecl *Decl = LVBase.dyn_cast<const ValueDecl*>()) { - if (Decl->hasAttr<WeakRefAttr>()) - return CGM.GetWeakRefReference(Decl); - if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Decl)) - return ConstantAddress(CGM.GetAddrOfFunction(FD), CharUnits::One()); - if (const VarDecl* VD = dyn_cast<VarDecl>(Decl)) { - // We can never refer to a variable with local storage. - if (!VD->hasLocalStorage()) { - CharUnits Align = CGM.getContext().getDeclAlign(VD); - if (VD->isFileVarDecl() || VD->hasExternalStorage()) - return ConstantAddress(CGM.GetAddrOfGlobalVar(VD), Align); - else if (VD->isLocalVarDecl()) { - auto Ptr = CGM.getOrCreateStaticVarDecl( - *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)); - return ConstantAddress(Ptr, Align); - } - } - } - return ConstantAddress::invalid(); - } - - Expr *E = const_cast<Expr*>(LVBase.get<const Expr*>()); - switch (E->getStmtClass()) { - default: break; - case Expr::CompoundLiteralExprClass: { - CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E); - CharUnits Align = CGM.getContext().getTypeAlignInChars(E->getType()); - if (llvm::GlobalVariable *Addr = - CGM.getAddrOfConstantCompoundLiteralIfEmitted(CLE)) - return ConstantAddress(Addr, Align); - - llvm::Constant* C = CGM.EmitConstantExpr(CLE->getInitializer(), - CLE->getType(), CGF); - // FIXME: "Leaked" on failure. - if (!C) return ConstantAddress::invalid(); - - auto GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(), - E->getType().isConstant(CGM.getContext()), - llvm::GlobalValue::InternalLinkage, - C, ".compoundliteral", nullptr, - llvm::GlobalVariable::NotThreadLocal, - CGM.getContext().getTargetAddressSpace(E->getType())); - GV->setAlignment(Align.getQuantity()); - CGM.setAddrOfConstantCompoundLiteral(CLE, GV); - return ConstantAddress(GV, Align); - } - case Expr::StringLiteralClass: - return CGM.GetAddrOfConstantStringFromLiteral(cast<StringLiteral>(E)); - case Expr::ObjCEncodeExprClass: - return CGM.GetAddrOfConstantStringFromObjCEncode(cast<ObjCEncodeExpr>(E)); - case Expr::ObjCStringLiteralClass: { - ObjCStringLiteral* SL = cast<ObjCStringLiteral>(E); - ConstantAddress C = - CGM.getObjCRuntime().GenerateConstantString(SL->getString()); - return C.getElementBitCast(ConvertType(E->getType())); - } - case Expr::PredefinedExprClass: { - unsigned Type = cast<PredefinedExpr>(E)->getIdentType(); - if (CGF) { - LValue Res = CGF->EmitPredefinedLValue(cast<PredefinedExpr>(E)); - return cast<ConstantAddress>(Res.getAddress()); - } else if (Type == PredefinedExpr::PrettyFunction) { - return CGM.GetAddrOfConstantCString("top level", ".tmp"); - } - - return CGM.GetAddrOfConstantCString("", ".tmp"); - } - case Expr::AddrLabelExprClass: { - assert(CGF && "Invalid address of label expression outside function."); - llvm::Constant *Ptr = - CGF->GetAddrOfLabel(cast<AddrLabelExpr>(E)->getLabel()); - Ptr = llvm::ConstantExpr::getBitCast(Ptr, ConvertType(E->getType())); - return ConstantAddress(Ptr, CharUnits::One()); - } - case Expr::CallExprClass: { - CallExpr* CE = cast<CallExpr>(E); - unsigned builtin = CE->getBuiltinCallee(); - if (builtin != - Builtin::BI__builtin___CFStringMakeConstantString && - builtin != - Builtin::BI__builtin___NSStringMakeConstantString) - break; - const Expr *Arg = CE->getArg(0)->IgnoreParenCasts(); - const StringLiteral *Literal = cast<StringLiteral>(Arg); - if (builtin == - Builtin::BI__builtin___NSStringMakeConstantString) { - return CGM.getObjCRuntime().GenerateConstantString(Literal); - } - // FIXME: need to deal with UCN conversion issues. - return CGM.GetAddrOfConstantCFString(Literal); - } - case Expr::BlockExprClass: { - StringRef FunctionName; - if (CGF) - FunctionName = CGF->CurFn->getName(); - else - FunctionName = "global"; - - // This is not really an l-value. - llvm::Constant *Ptr = - CGM.GetAddrOfGlobalBlock(cast<BlockExpr>(E), FunctionName); - return ConstantAddress(Ptr, CGM.getPointerAlign()); - } - case Expr::CXXTypeidExprClass: { - CXXTypeidExpr *Typeid = cast<CXXTypeidExpr>(E); - QualType T; - if (Typeid->isTypeOperand()) - T = Typeid->getTypeOperand(CGM.getContext()); - else - T = Typeid->getExprOperand()->getType(); - return ConstantAddress(CGM.GetAddrOfRTTIDescriptor(T), - CGM.getPointerAlign()); - } - case Expr::CXXUuidofExprClass: { - return CGM.GetAddrOfUuidDescriptor(cast<CXXUuidofExpr>(E)); - } - case Expr::MaterializeTemporaryExprClass: { - MaterializeTemporaryExpr *MTE = cast<MaterializeTemporaryExpr>(E); - assert(MTE->getStorageDuration() == SD_Static); - SmallVector<const Expr *, 2> CommaLHSs; - SmallVector<SubobjectAdjustment, 2> Adjustments; - const Expr *Inner = MTE->GetTemporaryExpr() - ->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments); - return CGM.GetAddrOfGlobalTemporary(MTE, Inner); - } - } - - return ConstantAddress::invalid(); - } }; } // end anonymous namespace. -bool ConstStructBuilder::Build(ConstExprEmitter *Emitter, +bool ConstStructBuilder::Build(ConstExprEmitter *ExprEmitter, llvm::ConstantStruct *Base, InitListExpr *Updater) { assert(Base && "base expression should not be empty"); @@ -1179,9 +1096,10 @@ bool ConstStructBuilder::Build(ConstExprEmitter *Emitter, if (!Init || isa<NoInitExpr>(Init)) ; // Do nothing. else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init)) - EltInit = Emitter->EmitDesignatedInitUpdater(EltInit, ChildILE); + EltInit = ExprEmitter->EmitDesignatedInitUpdater(EltInit, ChildILE, + Field->getType()); else - EltInit = CGM.EmitConstantExpr(Init, Field->getType(), CGF); + EltInit = Emitter.tryEmitPrivateForMemory(Init, Field->getType()); ++ElementNo; @@ -1200,26 +1118,294 @@ bool ConstStructBuilder::Build(ConstExprEmitter *Emitter, return true; } -llvm::Constant *CodeGenModule::EmitConstantInit(const VarDecl &D, - CodeGenFunction *CGF) { +llvm::Constant *ConstantEmitter::validateAndPopAbstract(llvm::Constant *C, + AbstractState saved) { + Abstract = saved.OldValue; + + assert(saved.OldPlaceholdersSize == PlaceholderAddresses.size() && + "created a placeholder while doing an abstract emission?"); + + // No validation necessary for now. + // No cleanup to do for now. + return C; +} + +llvm::Constant * +ConstantEmitter::tryEmitAbstractForInitializer(const VarDecl &D) { + auto state = pushAbstract(); + auto C = tryEmitPrivateForVarInit(D); + return validateAndPopAbstract(C, state); +} + +llvm::Constant * +ConstantEmitter::tryEmitAbstract(const Expr *E, QualType destType) { + auto state = pushAbstract(); + auto C = tryEmitPrivate(E, destType); + return validateAndPopAbstract(C, state); +} + +llvm::Constant * +ConstantEmitter::tryEmitAbstract(const APValue &value, QualType destType) { + auto state = pushAbstract(); + auto C = tryEmitPrivate(value, destType); + return validateAndPopAbstract(C, state); +} + +llvm::Constant * +ConstantEmitter::emitAbstract(const Expr *E, QualType destType) { + auto state = pushAbstract(); + auto C = tryEmitPrivate(E, destType); + C = validateAndPopAbstract(C, state); + if (!C) { + CGM.Error(E->getExprLoc(), + "internal error: could not emit constant value \"abstractly\""); + C = CGM.EmitNullConstant(destType); + } + return C; +} + +llvm::Constant * +ConstantEmitter::emitAbstract(SourceLocation loc, const APValue &value, + QualType destType) { + auto state = pushAbstract(); + auto C = tryEmitPrivate(value, destType); + C = validateAndPopAbstract(C, state); + if (!C) { + CGM.Error(loc, + "internal error: could not emit constant value \"abstractly\""); + C = CGM.EmitNullConstant(destType); + } + return C; +} + +llvm::Constant *ConstantEmitter::tryEmitForInitializer(const VarDecl &D) { + initializeNonAbstract(D.getType().getAddressSpace()); + return markIfFailed(tryEmitPrivateForVarInit(D)); +} + +llvm::Constant *ConstantEmitter::tryEmitForInitializer(const Expr *E, + LangAS destAddrSpace, + QualType destType) { + initializeNonAbstract(destAddrSpace); + return markIfFailed(tryEmitPrivateForMemory(E, destType)); +} + +llvm::Constant *ConstantEmitter::emitForInitializer(const APValue &value, + LangAS destAddrSpace, + QualType destType) { + initializeNonAbstract(destAddrSpace); + auto C = tryEmitPrivateForMemory(value, destType); + assert(C && "couldn't emit constant value non-abstractly?"); + return C; +} + +llvm::GlobalValue *ConstantEmitter::getCurrentAddrPrivate() { + assert(!Abstract && "cannot get current address for abstract constant"); + + + + // Make an obviously ill-formed global that should blow up compilation + // if it survives. + auto global = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, true, + llvm::GlobalValue::PrivateLinkage, + /*init*/ nullptr, + /*name*/ "", + /*before*/ nullptr, + llvm::GlobalVariable::NotThreadLocal, + CGM.getContext().getTargetAddressSpace(DestAddressSpace)); + + PlaceholderAddresses.push_back(std::make_pair(nullptr, global)); + + return global; +} + +void ConstantEmitter::registerCurrentAddrPrivate(llvm::Constant *signal, + llvm::GlobalValue *placeholder) { + assert(!PlaceholderAddresses.empty()); + assert(PlaceholderAddresses.back().first == nullptr); + assert(PlaceholderAddresses.back().second == placeholder); + PlaceholderAddresses.back().first = signal; +} + +namespace { + struct ReplacePlaceholders { + CodeGenModule &CGM; + + /// The base address of the global. + llvm::Constant *Base; + llvm::Type *BaseValueTy = nullptr; + + /// The placeholder addresses that were registered during emission. + llvm::DenseMap<llvm::Constant*, llvm::GlobalVariable*> PlaceholderAddresses; + + /// The locations of the placeholder signals. + llvm::DenseMap<llvm::GlobalVariable*, llvm::Constant*> Locations; + + /// The current index stack. We use a simple unsigned stack because + /// we assume that placeholders will be relatively sparse in the + /// initializer, but we cache the index values we find just in case. + llvm::SmallVector<unsigned, 8> Indices; + llvm::SmallVector<llvm::Constant*, 8> IndexValues; + + ReplacePlaceholders(CodeGenModule &CGM, llvm::Constant *base, + ArrayRef<std::pair<llvm::Constant*, + llvm::GlobalVariable*>> addresses) + : CGM(CGM), Base(base), + PlaceholderAddresses(addresses.begin(), addresses.end()) { + } + + void replaceInInitializer(llvm::Constant *init) { + // Remember the type of the top-most initializer. + BaseValueTy = init->getType(); + + // Initialize the stack. + Indices.push_back(0); + IndexValues.push_back(nullptr); + + // Recurse into the initializer. + findLocations(init); + + // Check invariants. + assert(IndexValues.size() == Indices.size() && "mismatch"); + assert(Indices.size() == 1 && "didn't pop all indices"); + + // Do the replacement; this basically invalidates 'init'. + assert(Locations.size() == PlaceholderAddresses.size() && + "missed a placeholder?"); + + // We're iterating over a hashtable, so this would be a source of + // non-determinism in compiler output *except* that we're just + // messing around with llvm::Constant structures, which never itself + // does anything that should be visible in compiler output. + for (auto &entry : Locations) { + assert(entry.first->getParent() == nullptr && "not a placeholder!"); + entry.first->replaceAllUsesWith(entry.second); + entry.first->eraseFromParent(); + } + } + + private: + void findLocations(llvm::Constant *init) { + // Recurse into aggregates. + if (auto agg = dyn_cast<llvm::ConstantAggregate>(init)) { + for (unsigned i = 0, e = agg->getNumOperands(); i != e; ++i) { + Indices.push_back(i); + IndexValues.push_back(nullptr); + + findLocations(agg->getOperand(i)); + + IndexValues.pop_back(); + Indices.pop_back(); + } + return; + } + + // Otherwise, check for registered constants. + while (true) { + auto it = PlaceholderAddresses.find(init); + if (it != PlaceholderAddresses.end()) { + setLocation(it->second); + break; + } + + // Look through bitcasts or other expressions. + if (auto expr = dyn_cast<llvm::ConstantExpr>(init)) { + init = expr->getOperand(0); + } else { + break; + } + } + } + + void setLocation(llvm::GlobalVariable *placeholder) { + assert(Locations.find(placeholder) == Locations.end() && + "already found location for placeholder!"); + + // Lazily fill in IndexValues with the values from Indices. + // We do this in reverse because we should always have a strict + // prefix of indices from the start. + assert(Indices.size() == IndexValues.size()); + for (size_t i = Indices.size() - 1; i != size_t(-1); --i) { + if (IndexValues[i]) { +#ifndef NDEBUG + for (size_t j = 0; j != i + 1; ++j) { + assert(IndexValues[j] && + isa<llvm::ConstantInt>(IndexValues[j]) && + cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() + == Indices[j]); + } +#endif + break; + } + + IndexValues[i] = llvm::ConstantInt::get(CGM.Int32Ty, Indices[i]); + } + + // Form a GEP and then bitcast to the placeholder type so that the + // replacement will succeed. + llvm::Constant *location = + llvm::ConstantExpr::getInBoundsGetElementPtr(BaseValueTy, + Base, IndexValues); + location = llvm::ConstantExpr::getBitCast(location, + placeholder->getType()); + + Locations.insert({placeholder, location}); + } + }; +} + +void ConstantEmitter::finalize(llvm::GlobalVariable *global) { + assert(InitializedNonAbstract && + "finalizing emitter that was used for abstract emission?"); + assert(!Finalized && "finalizing emitter multiple times"); + assert(global->getInitializer()); + + // Note that we might also be Failed. + Finalized = true; + + if (!PlaceholderAddresses.empty()) { + ReplacePlaceholders(CGM, global, PlaceholderAddresses) + .replaceInInitializer(global->getInitializer()); + PlaceholderAddresses.clear(); // satisfy + } +} + +ConstantEmitter::~ConstantEmitter() { + assert((!InitializedNonAbstract || Finalized || Failed) && + "not finalized after being initialized for non-abstract emission"); + assert(PlaceholderAddresses.empty() && "unhandled placeholders"); +} + +static QualType getNonMemoryType(CodeGenModule &CGM, QualType type) { + if (auto AT = type->getAs<AtomicType>()) { + return CGM.getContext().getQualifiedType(AT->getValueType(), + type.getQualifiers()); + } + return type; +} + +llvm::Constant *ConstantEmitter::tryEmitPrivateForVarInit(const VarDecl &D) { // Make a quick check if variable can be default NULL initialized // and avoid going through rest of code which may do, for c++11, // initialization of memory to all NULLs. if (!D.hasLocalStorage()) { - QualType Ty = D.getType(); - if (Ty->isArrayType()) - Ty = Context.getBaseElementType(Ty); + QualType Ty = CGM.getContext().getBaseElementType(D.getType()); if (Ty->isRecordType()) if (const CXXConstructExpr *E = dyn_cast_or_null<CXXConstructExpr>(D.getInit())) { const CXXConstructorDecl *CD = E->getConstructor(); if (CD->isTrivial() && CD->isDefaultConstructor()) - return EmitNullConstant(D.getType()); + return CGM.EmitNullConstant(D.getType()); } } - - if (const APValue *Value = D.evaluateValue()) - return EmitConstantValueForMemory(*Value, D.getType(), CGF); + + QualType destType = D.getType(); + + // Try to emit the initializer. Note that this can allow some things that + // are not allowed by tryEmitPrivateForMemory alone. + if (auto value = D.evaluateValue()) { + return tryEmitPrivateForMemory(*value, destType); + } // FIXME: Implement C++11 [basic.start.init]p2: if the initializer of a // reference is a constant expression, and the reference binds to a temporary, @@ -1227,42 +1413,95 @@ llvm::Constant *CodeGenModule::EmitConstantInit(const VarDecl &D, // incorrectly emit a prvalue constant in this case, and the calling code // interprets that as the (pointer) value of the reference, rather than the // desired value of the referee. - if (D.getType()->isReferenceType()) + if (destType->isReferenceType()) return nullptr; const Expr *E = D.getInit(); assert(E && "No initializer to emit"); - llvm::Constant* C = ConstExprEmitter(*this, CGF).Visit(const_cast<Expr*>(E)); - if (C && C->getType()->isIntegerTy(1)) { - llvm::Type *BoolTy = getTypes().ConvertTypeForMem(E->getType()); - C = llvm::ConstantExpr::getZExt(C, BoolTy); + auto nonMemoryDestType = getNonMemoryType(CGM, destType); + auto C = + ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), nonMemoryDestType); + return (C ? emitForMemory(C, destType) : nullptr); +} + +llvm::Constant * +ConstantEmitter::tryEmitAbstractForMemory(const Expr *E, QualType destType) { + auto nonMemoryDestType = getNonMemoryType(CGM, destType); + auto C = tryEmitAbstract(E, nonMemoryDestType); + return (C ? emitForMemory(C, destType) : nullptr); +} + +llvm::Constant * +ConstantEmitter::tryEmitAbstractForMemory(const APValue &value, + QualType destType) { + auto nonMemoryDestType = getNonMemoryType(CGM, destType); + auto C = tryEmitAbstract(value, nonMemoryDestType); + return (C ? emitForMemory(C, destType) : nullptr); +} + +llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const Expr *E, + QualType destType) { + auto nonMemoryDestType = getNonMemoryType(CGM, destType); + llvm::Constant *C = tryEmitPrivate(E, nonMemoryDestType); + return (C ? emitForMemory(C, destType) : nullptr); +} + +llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const APValue &value, + QualType destType) { + auto nonMemoryDestType = getNonMemoryType(CGM, destType); + auto C = tryEmitPrivate(value, nonMemoryDestType); + return (C ? emitForMemory(C, destType) : nullptr); +} + +llvm::Constant *ConstantEmitter::emitForMemory(CodeGenModule &CGM, + llvm::Constant *C, + QualType destType) { + // For an _Atomic-qualified constant, we may need to add tail padding. + if (auto AT = destType->getAs<AtomicType>()) { + QualType destValueType = AT->getValueType(); + C = emitForMemory(CGM, C, destValueType); + + uint64_t innerSize = CGM.getContext().getTypeSize(destValueType); + uint64_t outerSize = CGM.getContext().getTypeSize(destType); + if (innerSize == outerSize) + return C; + + assert(innerSize < outerSize && "emitted over-large constant for atomic"); + llvm::Constant *elts[] = { + C, + llvm::ConstantAggregateZero::get( + llvm::ArrayType::get(CGM.Int8Ty, (outerSize - innerSize) / 8)) + }; + return llvm::ConstantStruct::getAnon(elts); + } + + // Zero-extend bool. + if (C->getType()->isIntegerTy(1)) { + llvm::Type *boolTy = CGM.getTypes().ConvertTypeForMem(destType); + return llvm::ConstantExpr::getZExt(C, boolTy); } + return C; } -llvm::Constant *CodeGenModule::EmitConstantExpr(const Expr *E, - QualType DestType, - CodeGenFunction *CGF) { +llvm::Constant *ConstantEmitter::tryEmitPrivate(const Expr *E, + QualType destType) { Expr::EvalResult Result; bool Success = false; - if (DestType->isReferenceType()) - Success = E->EvaluateAsLValue(Result, Context); + if (destType->isReferenceType()) + Success = E->EvaluateAsLValue(Result, CGM.getContext()); else - Success = E->EvaluateAsRValue(Result, Context); + Success = E->EvaluateAsRValue(Result, CGM.getContext()); - llvm::Constant *C = nullptr; + llvm::Constant *C; if (Success && !Result.HasSideEffects) - C = EmitConstantValue(Result.Val, DestType, CGF); + C = tryEmitPrivate(Result.Val, destType); else - C = ConstExprEmitter(*this, CGF).Visit(const_cast<Expr*>(E)); + C = ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), destType); - if (C && C->getType()->isIntegerTy(1)) { - llvm::Type *BoolTy = getTypes().ConvertTypeForMem(E->getType()); - C = llvm::ConstantExpr::getZExt(C, BoolTy); - } return C; } @@ -1270,94 +1509,311 @@ llvm::Constant *CodeGenModule::getNullPointer(llvm::PointerType *T, QualType QT) return getTargetCodeGenInfo().getNullPointer(*this, T, QT); } -llvm::Constant *CodeGenModule::EmitConstantValue(const APValue &Value, - QualType DestType, - CodeGenFunction *CGF) { - // For an _Atomic-qualified constant, we may need to add tail padding. - if (auto *AT = DestType->getAs<AtomicType>()) { - QualType InnerType = AT->getValueType(); - auto *Inner = EmitConstantValue(Value, InnerType, CGF); - - uint64_t InnerSize = Context.getTypeSize(InnerType); - uint64_t OuterSize = Context.getTypeSize(DestType); - if (InnerSize == OuterSize) - return Inner; - - assert(InnerSize < OuterSize && "emitted over-large constant for atomic"); - llvm::Constant *Elts[] = { - Inner, - llvm::ConstantAggregateZero::get( - llvm::ArrayType::get(Int8Ty, (OuterSize - InnerSize) / 8)) - }; - return llvm::ConstantStruct::getAnon(Elts); - } +namespace { +/// A struct which can be used to peephole certain kinds of finalization +/// that normally happen during l-value emission. +struct ConstantLValue { + llvm::Constant *Value; + bool HasOffsetApplied; + + /*implicit*/ ConstantLValue(llvm::Constant *value, + bool hasOffsetApplied = false) + : Value(value), HasOffsetApplied(false) {} + + /*implicit*/ ConstantLValue(ConstantAddress address) + : ConstantLValue(address.getPointer()) {} +}; - switch (Value.getKind()) { - case APValue::Uninitialized: - llvm_unreachable("Constant expressions should be initialized."); - case APValue::LValue: { - llvm::Type *DestTy = getTypes().ConvertTypeForMem(DestType); - llvm::Constant *Offset = - llvm::ConstantInt::get(Int64Ty, Value.getLValueOffset().getQuantity()); - - llvm::Constant *C = nullptr; - - if (APValue::LValueBase LVBase = Value.getLValueBase()) { - // An array can be represented as an lvalue referring to the base. - if (isa<llvm::ArrayType>(DestTy)) { - assert(Offset->isNullValue() && "offset on array initializer"); - return ConstExprEmitter(*this, CGF).Visit( - const_cast<Expr*>(LVBase.get<const Expr*>())); - } +/// A helper class for emitting constant l-values. +class ConstantLValueEmitter : public ConstStmtVisitor<ConstantLValueEmitter, + ConstantLValue> { + CodeGenModule &CGM; + ConstantEmitter &Emitter; + const APValue &Value; + QualType DestType; - C = ConstExprEmitter(*this, CGF).EmitLValue(LVBase).getPointer(); + // Befriend StmtVisitorBase so that we don't have to expose Visit*. + friend StmtVisitorBase; - // Apply offset if necessary. - if (!Offset->isNullValue()) { - unsigned AS = C->getType()->getPointerAddressSpace(); - llvm::Type *CharPtrTy = Int8Ty->getPointerTo(AS); - llvm::Constant *Casted = llvm::ConstantExpr::getBitCast(C, CharPtrTy); - Casted = llvm::ConstantExpr::getGetElementPtr(Int8Ty, Casted, Offset); - C = llvm::ConstantExpr::getPointerCast(Casted, C->getType()); - } +public: + ConstantLValueEmitter(ConstantEmitter &emitter, const APValue &value, + QualType destType) + : CGM(emitter.CGM), Emitter(emitter), Value(value), DestType(destType) {} - // Convert to the appropriate type; this could be an lvalue for - // an integer. - if (isa<llvm::PointerType>(DestTy)) - return llvm::ConstantExpr::getPointerCast(C, DestTy); + llvm::Constant *tryEmit(); - return llvm::ConstantExpr::getPtrToInt(C, DestTy); - } else { - C = Offset; - - // Convert to the appropriate type; this could be an lvalue for - // an integer. - if (auto PT = dyn_cast<llvm::PointerType>(DestTy)) { - if (Value.isNullPointer()) - return getNullPointer(PT, DestType); - // Convert the integer to a pointer-sized integer before converting it - // to a pointer. - C = llvm::ConstantExpr::getIntegerCast( - C, getDataLayout().getIntPtrType(DestTy), - /*isSigned=*/false); - return llvm::ConstantExpr::getIntToPtr(C, DestTy); - } +private: + llvm::Constant *tryEmitAbsolute(llvm::Type *destTy); + ConstantLValue tryEmitBase(const APValue::LValueBase &base); + + ConstantLValue VisitStmt(const Stmt *S) { return nullptr; } + ConstantLValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E); + ConstantLValue VisitStringLiteral(const StringLiteral *E); + ConstantLValue VisitObjCEncodeExpr(const ObjCEncodeExpr *E); + ConstantLValue VisitObjCStringLiteral(const ObjCStringLiteral *E); + ConstantLValue VisitPredefinedExpr(const PredefinedExpr *E); + ConstantLValue VisitAddrLabelExpr(const AddrLabelExpr *E); + ConstantLValue VisitCallExpr(const CallExpr *E); + ConstantLValue VisitBlockExpr(const BlockExpr *E); + ConstantLValue VisitCXXTypeidExpr(const CXXTypeidExpr *E); + ConstantLValue VisitCXXUuidofExpr(const CXXUuidofExpr *E); + ConstantLValue VisitMaterializeTemporaryExpr( + const MaterializeTemporaryExpr *E); + + bool hasNonZeroOffset() const { + return !Value.getLValueOffset().isZero(); + } - // If the types don't match this should only be a truncate. - if (C->getType() != DestTy) - return llvm::ConstantExpr::getTrunc(C, DestTy); + /// Return the value offset. + llvm::Constant *getOffset() { + return llvm::ConstantInt::get(CGM.Int64Ty, + Value.getLValueOffset().getQuantity()); + } + /// Apply the value offset to the given constant. + llvm::Constant *applyOffset(llvm::Constant *C) { + if (!hasNonZeroOffset()) return C; + + llvm::Type *origPtrTy = C->getType(); + unsigned AS = origPtrTy->getPointerAddressSpace(); + llvm::Type *charPtrTy = CGM.Int8Ty->getPointerTo(AS); + C = llvm::ConstantExpr::getBitCast(C, charPtrTy); + C = llvm::ConstantExpr::getGetElementPtr(CGM.Int8Ty, C, getOffset()); + C = llvm::ConstantExpr::getPointerCast(C, origPtrTy); + return C; + } +}; + +} + +llvm::Constant *ConstantLValueEmitter::tryEmit() { + const APValue::LValueBase &base = Value.getLValueBase(); + + // Certain special array initializers are represented in APValue + // as l-values referring to the base expression which generates the + // array. This happens with e.g. string literals. These should + // probably just get their own representation kind in APValue. + if (DestType->isArrayType()) { + assert(!hasNonZeroOffset() && "offset on array initializer"); + auto expr = const_cast<Expr*>(base.get<const Expr*>()); + return ConstExprEmitter(Emitter).Visit(expr, DestType); + } + + // Otherwise, the destination type should be a pointer or reference + // type, but it might also be a cast thereof. + // + // FIXME: the chain of casts required should be reflected in the APValue. + // We need this in order to correctly handle things like a ptrtoint of a + // non-zero null pointer and addrspace casts that aren't trivially + // represented in LLVM IR. + auto destTy = CGM.getTypes().ConvertTypeForMem(DestType); + assert(isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy)); + + // If there's no base at all, this is a null or absolute pointer, + // possibly cast back to an integer type. + if (!base) { + return tryEmitAbsolute(destTy); + } + + // Otherwise, try to emit the base. + ConstantLValue result = tryEmitBase(base); + + // If that failed, we're done. + llvm::Constant *value = result.Value; + if (!value) return nullptr; + + // Apply the offset if necessary and not already done. + if (!result.HasOffsetApplied) { + value = applyOffset(value); + } + + // Convert to the appropriate type; this could be an lvalue for + // an integer. FIXME: performAddrSpaceCast + if (isa<llvm::PointerType>(destTy)) + return llvm::ConstantExpr::getPointerCast(value, destTy); + + return llvm::ConstantExpr::getPtrToInt(value, destTy); +} + +/// Try to emit an absolute l-value, such as a null pointer or an integer +/// bitcast to pointer type. +llvm::Constant * +ConstantLValueEmitter::tryEmitAbsolute(llvm::Type *destTy) { + auto offset = getOffset(); + + // If we're producing a pointer, this is easy. + if (auto destPtrTy = cast<llvm::PointerType>(destTy)) { + if (Value.isNullPointer()) { + // FIXME: integer offsets from non-zero null pointers. + return CGM.getNullPointer(destPtrTy, DestType); } + + // Convert the integer to a pointer-sized integer before converting it + // to a pointer. + // FIXME: signedness depends on the original integer type. + auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy); + llvm::Constant *C = offset; + C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy, + /*isSigned*/ false); + C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy); + return C; + } + + // Otherwise, we're basically returning an integer constant. + + // FIXME: this does the wrong thing with ptrtoint of a null pointer, + // but since we don't know the original pointer type, there's not much + // we can do about it. + + auto C = getOffset(); + C = llvm::ConstantExpr::getIntegerCast(C, destTy, /*isSigned*/ false); + return C; +} + +ConstantLValue +ConstantLValueEmitter::tryEmitBase(const APValue::LValueBase &base) { + // Handle values. + if (const ValueDecl *D = base.dyn_cast<const ValueDecl*>()) { + if (D->hasAttr<WeakRefAttr>()) + return CGM.GetWeakRefReference(D).getPointer(); + + if (auto FD = dyn_cast<FunctionDecl>(D)) + return CGM.GetAddrOfFunction(FD); + + if (auto VD = dyn_cast<VarDecl>(D)) { + // We can never refer to a variable with local storage. + if (!VD->hasLocalStorage()) { + if (VD->isFileVarDecl() || VD->hasExternalStorage()) + return CGM.GetAddrOfGlobalVar(VD); + + if (VD->isLocalVarDecl()) { + return CGM.getOrCreateStaticVarDecl( + *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)); + } + } + } + + return nullptr; + } + + // Otherwise, it must be an expression. + return Visit(base.get<const Expr*>()); +} + +ConstantLValue +ConstantLValueEmitter::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) { + return tryEmitGlobalCompoundLiteral(CGM, Emitter.CGF, E); +} + +ConstantLValue +ConstantLValueEmitter::VisitStringLiteral(const StringLiteral *E) { + return CGM.GetAddrOfConstantStringFromLiteral(E); +} + +ConstantLValue +ConstantLValueEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) { + return CGM.GetAddrOfConstantStringFromObjCEncode(E); +} + +ConstantLValue +ConstantLValueEmitter::VisitObjCStringLiteral(const ObjCStringLiteral *E) { + auto C = CGM.getObjCRuntime().GenerateConstantString(E->getString()); + return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(E->getType())); +} + +ConstantLValue +ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) { + if (auto CGF = Emitter.CGF) { + LValue Res = CGF->EmitPredefinedLValue(E); + return cast<ConstantAddress>(Res.getAddress()); + } + + auto kind = E->getIdentType(); + if (kind == PredefinedExpr::PrettyFunction) { + return CGM.GetAddrOfConstantCString("top level", ".tmp"); + } + + return CGM.GetAddrOfConstantCString("", ".tmp"); +} + +ConstantLValue +ConstantLValueEmitter::VisitAddrLabelExpr(const AddrLabelExpr *E) { + assert(Emitter.CGF && "Invalid address of label expression outside function"); + llvm::Constant *Ptr = Emitter.CGF->GetAddrOfLabel(E->getLabel()); + Ptr = llvm::ConstantExpr::getBitCast(Ptr, + CGM.getTypes().ConvertType(E->getType())); + return Ptr; +} + +ConstantLValue +ConstantLValueEmitter::VisitCallExpr(const CallExpr *E) { + unsigned builtin = E->getBuiltinCallee(); + if (builtin != Builtin::BI__builtin___CFStringMakeConstantString && + builtin != Builtin::BI__builtin___NSStringMakeConstantString) + return nullptr; + + auto literal = cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts()); + if (builtin == Builtin::BI__builtin___NSStringMakeConstantString) { + return CGM.getObjCRuntime().GenerateConstantString(literal); + } else { + // FIXME: need to deal with UCN conversion issues. + return CGM.GetAddrOfConstantCFString(literal); } +} + +ConstantLValue +ConstantLValueEmitter::VisitBlockExpr(const BlockExpr *E) { + StringRef functionName; + if (auto CGF = Emitter.CGF) + functionName = CGF->CurFn->getName(); + else + functionName = "global"; + + return CGM.GetAddrOfGlobalBlock(E, functionName); +} + +ConstantLValue +ConstantLValueEmitter::VisitCXXTypeidExpr(const CXXTypeidExpr *E) { + QualType T; + if (E->isTypeOperand()) + T = E->getTypeOperand(CGM.getContext()); + else + T = E->getExprOperand()->getType(); + return CGM.GetAddrOfRTTIDescriptor(T); +} + +ConstantLValue +ConstantLValueEmitter::VisitCXXUuidofExpr(const CXXUuidofExpr *E) { + return CGM.GetAddrOfUuidDescriptor(E); +} + +ConstantLValue +ConstantLValueEmitter::VisitMaterializeTemporaryExpr( + const MaterializeTemporaryExpr *E) { + assert(E->getStorageDuration() == SD_Static); + SmallVector<const Expr *, 2> CommaLHSs; + SmallVector<SubobjectAdjustment, 2> Adjustments; + const Expr *Inner = E->GetTemporaryExpr() + ->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments); + return CGM.GetAddrOfGlobalTemporary(E, Inner); +} + +llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value, + QualType DestType) { + switch (Value.getKind()) { + case APValue::Uninitialized: + llvm_unreachable("Constant expressions should be initialized."); + case APValue::LValue: + return ConstantLValueEmitter(*this, Value, DestType).tryEmit(); case APValue::Int: - return llvm::ConstantInt::get(VMContext, Value.getInt()); + return llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getInt()); case APValue::ComplexInt: { llvm::Constant *Complex[2]; - Complex[0] = llvm::ConstantInt::get(VMContext, + Complex[0] = llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getComplexIntReal()); - Complex[1] = llvm::ConstantInt::get(VMContext, + Complex[1] = llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getComplexIntImag()); // FIXME: the target may want to specify that this is packed. @@ -1368,18 +1824,19 @@ llvm::Constant *CodeGenModule::EmitConstantValue(const APValue &Value, case APValue::Float: { const llvm::APFloat &Init = Value.getFloat(); if (&Init.getSemantics() == &llvm::APFloat::IEEEhalf() && - !Context.getLangOpts().NativeHalfType && - !Context.getLangOpts().HalfArgsAndReturns) - return llvm::ConstantInt::get(VMContext, Init.bitcastToAPInt()); + !CGM.getContext().getLangOpts().NativeHalfType && + CGM.getContext().getTargetInfo().useFP16ConversionIntrinsics()) + return llvm::ConstantInt::get(CGM.getLLVMContext(), + Init.bitcastToAPInt()); else - return llvm::ConstantFP::get(VMContext, Init); + return llvm::ConstantFP::get(CGM.getLLVMContext(), Init); } case APValue::ComplexFloat: { llvm::Constant *Complex[2]; - Complex[0] = llvm::ConstantFP::get(VMContext, + Complex[0] = llvm::ConstantFP::get(CGM.getLLVMContext(), Value.getComplexFloatReal()); - Complex[1] = llvm::ConstantFP::get(VMContext, + Complex[1] = llvm::ConstantFP::get(CGM.getLLVMContext(), Value.getComplexFloatImag()); // FIXME: the target may want to specify that this is packed. @@ -1394,9 +1851,9 @@ llvm::Constant *CodeGenModule::EmitConstantValue(const APValue &Value, for (unsigned I = 0; I != NumElts; ++I) { const APValue &Elt = Value.getVectorElt(I); if (Elt.isInt()) - Inits[I] = llvm::ConstantInt::get(VMContext, Elt.getInt()); + Inits[I] = llvm::ConstantInt::get(CGM.getLLVMContext(), Elt.getInt()); else if (Elt.isFloat()) - Inits[I] = llvm::ConstantFP::get(VMContext, Elt.getFloat()); + Inits[I] = llvm::ConstantFP::get(CGM.getLLVMContext(), Elt.getFloat()); else llvm_unreachable("unsupported vector element type"); } @@ -1405,13 +1862,14 @@ llvm::Constant *CodeGenModule::EmitConstantValue(const APValue &Value, case APValue::AddrLabelDiff: { const AddrLabelExpr *LHSExpr = Value.getAddrLabelDiffLHS(); const AddrLabelExpr *RHSExpr = Value.getAddrLabelDiffRHS(); - llvm::Constant *LHS = EmitConstantExpr(LHSExpr, LHSExpr->getType(), CGF); - llvm::Constant *RHS = EmitConstantExpr(RHSExpr, RHSExpr->getType(), CGF); + llvm::Constant *LHS = tryEmitPrivate(LHSExpr, LHSExpr->getType()); + llvm::Constant *RHS = tryEmitPrivate(RHSExpr, RHSExpr->getType()); + if (!LHS || !RHS) return nullptr; // Compute difference - llvm::Type *ResultType = getTypes().ConvertType(DestType); - LHS = llvm::ConstantExpr::getPtrToInt(LHS, IntPtrTy); - RHS = llvm::ConstantExpr::getPtrToInt(RHS, IntPtrTy); + llvm::Type *ResultType = CGM.getTypes().ConvertType(DestType); + LHS = llvm::ConstantExpr::getPtrToInt(LHS, CGM.IntPtrTy); + RHS = llvm::ConstantExpr::getPtrToInt(RHS, CGM.IntPtrTy); llvm::Constant *AddrLabelDiff = llvm::ConstantExpr::getSub(LHS, RHS); // LLVM is a bit sensitive about the exact format of the @@ -1421,21 +1879,21 @@ llvm::Constant *CodeGenModule::EmitConstantValue(const APValue &Value, } case APValue::Struct: case APValue::Union: - return ConstStructBuilder::BuildStruct(*this, CGF, Value, DestType); + return ConstStructBuilder::BuildStruct(*this, Value, DestType); case APValue::Array: { - const ArrayType *CAT = Context.getAsArrayType(DestType); + const ArrayType *CAT = CGM.getContext().getAsArrayType(DestType); unsigned NumElements = Value.getArraySize(); unsigned NumInitElts = Value.getArrayInitializedElts(); // Emit array filler, if there is one. llvm::Constant *Filler = nullptr; if (Value.hasArrayFiller()) - Filler = EmitConstantValueForMemory(Value.getArrayFiller(), - CAT->getElementType(), CGF); + Filler = tryEmitAbstractForMemory(Value.getArrayFiller(), + CAT->getElementType()); // Emit initializer elements. llvm::Type *CommonElementType = - getTypes().ConvertType(CAT->getElementType()); + CGM.getTypes().ConvertType(CAT->getElementType()); // Try to use a ConstantAggregateZero if we can. if (Filler && Filler->isNullValue() && !NumInitElts) { @@ -1444,15 +1902,21 @@ llvm::Constant *CodeGenModule::EmitConstantValue(const APValue &Value, return llvm::ConstantAggregateZero::get(AType); } - std::vector<llvm::Constant*> Elts; + SmallVector<llvm::Constant*, 16> Elts; Elts.reserve(NumElements); for (unsigned I = 0; I < NumElements; ++I) { llvm::Constant *C = Filler; - if (I < NumInitElts) - C = EmitConstantValueForMemory(Value.getArrayInitializedElt(I), - CAT->getElementType(), CGF); - else - assert(Filler && "Missing filler for implicit elements of initializer"); + if (I < NumInitElts) { + C = tryEmitPrivateForMemory(Value.getArrayInitializedElt(I), + CAT->getElementType()); + } else if (!Filler) { + assert(Value.hasArrayFiller() && + "Missing filler for implicit elements of initializer"); + C = tryEmitPrivateForMemory(Value.getArrayFiller(), + CAT->getElementType()); + } + if (!C) return nullptr; + if (I == 0) CommonElementType = C->getType(); else if (C->getType() != CommonElementType) @@ -1466,7 +1930,8 @@ llvm::Constant *CodeGenModule::EmitConstantValue(const APValue &Value, Types.reserve(NumElements); for (unsigned i = 0, e = Elts.size(); i < e; ++i) Types.push_back(Elts[i]->getType()); - llvm::StructType *SType = llvm::StructType::get(VMContext, Types, true); + llvm::StructType *SType = + llvm::StructType::get(CGM.getLLVMContext(), Types, true); return llvm::ConstantStruct::get(SType, Elts); } @@ -1475,23 +1940,11 @@ llvm::Constant *CodeGenModule::EmitConstantValue(const APValue &Value, return llvm::ConstantArray::get(AType, Elts); } case APValue::MemberPointer: - return getCXXABI().EmitMemberPointer(Value, DestType); + return CGM.getCXXABI().EmitMemberPointer(Value, DestType); } llvm_unreachable("Unknown APValue kind"); } -llvm::Constant * -CodeGenModule::EmitConstantValueForMemory(const APValue &Value, - QualType DestType, - CodeGenFunction *CGF) { - llvm::Constant *C = EmitConstantValue(Value, DestType, CGF); - if (C->getType()->isIntegerTy(1)) { - llvm::Type *BoolTy = getTypes().ConvertTypeForMem(DestType); - C = llvm::ConstantExpr::getZExt(C, BoolTy); - } - return C; -} - llvm::GlobalVariable *CodeGenModule::getAddrOfConstantCompoundLiteralIfEmitted( const CompoundLiteralExpr *E) { return EmittedCompoundLiterals.lookup(E); @@ -1507,7 +1960,7 @@ void CodeGenModule::setAddrOfConstantCompoundLiteral( ConstantAddress CodeGenModule::GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *E) { assert(E->isFileScope() && "not a file-scope compound literal expr"); - return ConstExprEmitter(*this, nullptr).EmitLValue(E); + return tryEmitGlobalCompoundLiteral(*this, nullptr, E); } llvm::Constant * @@ -1629,6 +2082,11 @@ static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM, return EmitNullConstant(CGM, base, /*asCompleteObject=*/false); } +llvm::Constant *ConstantEmitter::emitNullForMemory(CodeGenModule &CGM, + QualType T) { + return emitForMemory(CGM, CGM.EmitNullConstant(T), T); +} + llvm::Constant *CodeGenModule::EmitNullConstant(QualType T) { if (T->getAs<PointerType>()) return getNullPointer( @@ -1643,7 +2101,8 @@ llvm::Constant *CodeGenModule::EmitNullConstant(QualType T) { QualType ElementTy = CAT->getElementType(); - llvm::Constant *Element = EmitNullConstant(ElementTy); + llvm::Constant *Element = + ConstantEmitter::emitNullForMemory(*this, ElementTy); unsigned NumElements = CAT->getSize().getZExtValue(); SmallVector<llvm::Constant *, 8> Array(NumElements, Element); return llvm::ConstantArray::get(ATy, Array); |