//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This contains code to emit Expr nodes as LLVM code. // //===----------------------------------------------------------------------===// #include "CodeGenFunction.h" #include "CodeGenModule.h" #include "CGCall.h" #include "CGObjCRuntime.h" #include "clang/AST/ASTContext.h" #include "clang/AST/DeclObjC.h" #include "llvm/Target/TargetData.h" using namespace clang; using namespace CodeGen; //===--------------------------------------------------------------------===// // Miscellaneous Helper Methods //===--------------------------------------------------------------------===// /// CreateTempAlloca - This creates a alloca and inserts it into the entry /// block. llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(const llvm::Type *Ty, const char *Name) { return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt); } /// EvaluateExprAsBool - Perform the usual unary conversions on the specified /// expression and compare the result against zero, returning an Int1Ty value. llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) { QualType BoolTy = getContext().BoolTy; if (!E->getType()->isAnyComplexType()) return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy); return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy); } /// EmitAnyExpr - Emit code to compute the specified expression which can have /// any type. The result is returned as an RValue struct. If this is an /// aggregate expression, the aggloc/agglocvolatile arguments indicate where /// the result should be returned. RValue CodeGenFunction::EmitAnyExpr(const Expr *E, llvm::Value *AggLoc, bool isAggLocVolatile) { if (!hasAggregateLLVMType(E->getType())) return RValue::get(EmitScalarExpr(E)); else if (E->getType()->isAnyComplexType()) return RValue::getComplex(EmitComplexExpr(E)); EmitAggExpr(E, AggLoc, isAggLocVolatile); return RValue::getAggregate(AggLoc); } /// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result /// will always be accessible even if no aggregate location is /// provided. RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E, llvm::Value *AggLoc, bool isAggLocVolatile) { if (!AggLoc && hasAggregateLLVMType(E->getType()) && !E->getType()->isAnyComplexType()) AggLoc = CreateTempAlloca(ConvertType(E->getType()), "agg.tmp"); return EmitAnyExpr(E, AggLoc, isAggLocVolatile); } /// getAccessedFieldNo - Given an encoded value and a result number, return /// the input field number being accessed. unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx, const llvm::Constant *Elts) { if (isa(Elts)) return 0; return cast(Elts->getOperand(Idx))->getZExtValue(); } //===----------------------------------------------------------------------===// // LValue Expression Emission //===----------------------------------------------------------------------===// RValue CodeGenFunction::GetUndefRValue(QualType Ty) { if (Ty->isVoidType()) { return RValue::get(0); } else if (const ComplexType *CTy = Ty->getAsComplexType()) { const llvm::Type *EltTy = ConvertType(CTy->getElementType()); llvm::Value *U = llvm::UndefValue::get(EltTy); return RValue::getComplex(std::make_pair(U, U)); } else if (hasAggregateLLVMType(Ty)) { const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty)); return RValue::getAggregate(llvm::UndefValue::get(LTy)); } else { return RValue::get(llvm::UndefValue::get(ConvertType(Ty))); } } RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E, const char *Name) { ErrorUnsupported(E, Name); return GetUndefRValue(E->getType()); } LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E, const char *Name) { ErrorUnsupported(E, Name); llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType())); return LValue::MakeAddr(llvm::UndefValue::get(Ty), E->getType().getCVRQualifiers(), getContext().getObjCGCAttrKind(E->getType())); } /// EmitLValue - Emit code to compute a designator that specifies the location /// of the expression. /// /// This can return one of two things: a simple address or a bitfield /// reference. In either case, the LLVM Value* in the LValue structure is /// guaranteed to be an LLVM pointer type. /// /// If this returns a bitfield reference, nothing about the pointee type of /// the LLVM value is known: For example, it may not be a pointer to an /// integer. /// /// If this returns a normal address, and if the lvalue's C type is fixed /// size, this method guarantees that the returned pointer type will point to /// an LLVM type of the same size of the lvalue's type. If the lvalue has a /// variable length type, this is not possible. /// LValue CodeGenFunction::EmitLValue(const Expr *E) { switch (E->getStmtClass()) { default: return EmitUnsupportedLValue(E, "l-value expression"); case Expr::BinaryOperatorClass: return EmitBinaryOperatorLValue(cast(E)); case Expr::CallExprClass: case Expr::CXXOperatorCallExprClass: return EmitCallExprLValue(cast(E)); case Expr::VAArgExprClass: return EmitVAArgExprLValue(cast(E)); case Expr::DeclRefExprClass: case Expr::QualifiedDeclRefExprClass: return EmitDeclRefLValue(cast(E)); case Expr::ParenExprClass:return EmitLValue(cast(E)->getSubExpr()); case Expr::PredefinedExprClass: return EmitPredefinedLValue(cast(E)); case Expr::StringLiteralClass: return EmitStringLiteralLValue(cast(E)); case Expr::CXXConditionDeclExprClass: return EmitCXXConditionDeclLValue(cast(E)); case Expr::ObjCMessageExprClass: return EmitObjCMessageExprLValue(cast(E)); case Expr::ObjCIvarRefExprClass: return EmitObjCIvarRefLValue(cast(E)); case Expr::ObjCPropertyRefExprClass: return EmitObjCPropertyRefLValue(cast(E)); case Expr::ObjCKVCRefExprClass: return EmitObjCKVCRefLValue(cast(E)); case Expr::ObjCSuperExprClass: return EmitObjCSuperExpr(cast(E)); case Expr::UnaryOperatorClass: return EmitUnaryOpLValue(cast(E)); case Expr::ArraySubscriptExprClass: return EmitArraySubscriptExpr(cast(E)); case Expr::ExtVectorElementExprClass: return EmitExtVectorElementExpr(cast(E)); case Expr::MemberExprClass: return EmitMemberExpr(cast(E)); case Expr::CompoundLiteralExprClass: return EmitCompoundLiteralLValue(cast(E)); case Expr::ChooseExprClass: // __builtin_choose_expr is the lvalue of the selected operand. if (cast(E)->isConditionTrue(getContext())) return EmitLValue(cast(E)->getLHS()); else return EmitLValue(cast(E)->getRHS()); } } llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile, QualType Ty) { llvm::Value *V = Builder.CreateLoad(Addr, Volatile, "tmp"); // Bool can have different representation in memory than in // registers. if (Ty->isBooleanType()) if (V->getType() != llvm::Type::Int1Ty) V = Builder.CreateTrunc(V, llvm::Type::Int1Ty, "tobool"); return V; } void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr, bool Volatile) { // Handle stores of types which have different representations in // memory and as LLVM values. // FIXME: We shouldn't be this loose, we should only do this // conversion when we have a type we know has a different memory // representation (e.g., bool). const llvm::Type *SrcTy = Value->getType(); const llvm::PointerType *DstPtr = cast(Addr->getType()); if (DstPtr->getElementType() != SrcTy) { const llvm::Type *MemTy = llvm::PointerType::get(SrcTy, DstPtr->getAddressSpace()); Addr = Builder.CreateBitCast(Addr, MemTy, "storetmp"); } Builder.CreateStore(Value, Addr, Volatile); } /// EmitLoadOfLValue - Given an expression that represents a value lvalue, /// this method emits the address of the lvalue, then loads the result as an /// rvalue, returning the rvalue. RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, QualType ExprType) { if (LV.isObjCWeak()) { // load of a __weak object. llvm::Value *AddrWeakObj = LV.getAddress(); llvm::Value *read_weak = CGM.getObjCRuntime().EmitObjCWeakRead(*this, AddrWeakObj); return RValue::get(read_weak); } if (LV.isSimple()) { llvm::Value *Ptr = LV.getAddress(); const llvm::Type *EltTy = cast(Ptr->getType())->getElementType(); // Simple scalar l-value. if (EltTy->isSingleValueType()) return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(), ExprType)); assert(ExprType->isFunctionType() && "Unknown scalar value"); return RValue::get(Ptr); } if (LV.isVectorElt()) { llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(), LV.isVolatileQualified(), "tmp"); return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(), "vecext")); } // If this is a reference to a subset of the elements of a vector, either // shuffle the input or extract/insert them as appropriate. if (LV.isExtVectorElt()) return EmitLoadOfExtVectorElementLValue(LV, ExprType); if (LV.isBitfield()) return EmitLoadOfBitfieldLValue(LV, ExprType); if (LV.isPropertyRef()) return EmitLoadOfPropertyRefLValue(LV, ExprType); assert(LV.isKVCRef() && "Unknown LValue type!"); return EmitLoadOfKVCRefLValue(LV, ExprType); } RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV, QualType ExprType) { unsigned StartBit = LV.getBitfieldStartBit(); unsigned BitfieldSize = LV.getBitfieldSize(); llvm::Value *Ptr = LV.getBitfieldAddr(); const llvm::Type *EltTy = cast(Ptr->getType())->getElementType(); unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy); // In some cases the bitfield may straddle two memory locations. // Currently we load the entire bitfield, then do the magic to // sign-extend it if necessary. This results in somewhat more code // than necessary for the common case (one load), since two shifts // accomplish both the masking and sign extension. unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit); llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "tmp"); // Shift to proper location. if (StartBit) Val = Builder.CreateLShr(Val, llvm::ConstantInt::get(EltTy, StartBit), "bf.lo"); // Mask off unused bits. llvm::Constant *LowMask = llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, LowBits)); Val = Builder.CreateAnd(Val, LowMask, "bf.lo.cleared"); // Fetch the high bits if necessary. if (LowBits < BitfieldSize) { unsigned HighBits = BitfieldSize - LowBits; llvm::Value *HighPtr = Builder.CreateGEP(Ptr, llvm::ConstantInt::get(llvm::Type::Int32Ty, 1), "bf.ptr.hi"); llvm::Value *HighVal = Builder.CreateLoad(HighPtr, LV.isVolatileQualified(), "tmp"); // Mask off unused bits. llvm::Constant *HighMask = llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, HighBits)); HighVal = Builder.CreateAnd(HighVal, HighMask, "bf.lo.cleared"); // Shift to proper location and or in to bitfield value. HighVal = Builder.CreateShl(HighVal, llvm::ConstantInt::get(EltTy, LowBits)); Val = Builder.CreateOr(Val, HighVal, "bf.val"); } // Sign extend if necessary. if (LV.isBitfieldSigned()) { llvm::Value *ExtraBits = llvm::ConstantInt::get(EltTy, EltTySize - BitfieldSize); Val = Builder.CreateAShr(Builder.CreateShl(Val, ExtraBits), ExtraBits, "bf.val.sext"); } // The bitfield type and the normal type differ when the storage sizes // differ (currently just _Bool). Val = Builder.CreateIntCast(Val, ConvertType(ExprType), false, "tmp"); return RValue::get(Val); } RValue CodeGenFunction::EmitLoadOfPropertyRefLValue(LValue LV, QualType ExprType) { return EmitObjCPropertyGet(LV.getPropertyRefExpr()); } RValue CodeGenFunction::EmitLoadOfKVCRefLValue(LValue LV, QualType ExprType) { return EmitObjCPropertyGet(LV.getKVCRefExpr()); } // If this is a reference to a subset of the elements of a vector, create an // appropriate shufflevector. RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV, QualType ExprType) { llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(), LV.isVolatileQualified(), "tmp"); const llvm::Constant *Elts = LV.getExtVectorElts(); // If the result of the expression is a non-vector type, we must be // extracting a single element. Just codegen as an extractelement. const VectorType *ExprVT = ExprType->getAsVectorType(); if (!ExprVT) { unsigned InIdx = getAccessedFieldNo(0, Elts); llvm::Value *Elt = llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx); return RValue::get(Builder.CreateExtractElement(Vec, Elt, "tmp")); } // Always use shuffle vector to try to retain the original program structure unsigned NumResultElts = ExprVT->getNumElements(); llvm::SmallVector Mask; for (unsigned i = 0; i != NumResultElts; ++i) { unsigned InIdx = getAccessedFieldNo(i, Elts); Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx)); } llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size()); Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()), MaskV, "tmp"); return RValue::get(Vec); } /// EmitStoreThroughLValue - Store the specified rvalue into the specified /// lvalue, where both are guaranteed to the have the same type, and that type /// is 'Ty'. void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst, QualType Ty) { if (!Dst.isSimple()) { if (Dst.isVectorElt()) { // Read/modify/write the vector, inserting the new element. llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(), Dst.isVolatileQualified(), "tmp"); Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(), Dst.getVectorIdx(), "vecins"); Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified()); return; } // If this is an update of extended vector elements, insert them as // appropriate. if (Dst.isExtVectorElt()) return EmitStoreThroughExtVectorComponentLValue(Src, Dst, Ty); if (Dst.isBitfield()) return EmitStoreThroughBitfieldLValue(Src, Dst, Ty); if (Dst.isPropertyRef()) return EmitStoreThroughPropertyRefLValue(Src, Dst, Ty); if (Dst.isKVCRef()) return EmitStoreThroughKVCRefLValue(Src, Dst, Ty); assert(0 && "Unknown LValue type"); } if (Dst.isObjCWeak()) { // load of a __weak object. llvm::Value *LvalueDst = Dst.getAddress(); llvm::Value *src = Src.getScalarVal(); CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst); return; } if (Dst.isObjCStrong()) { // load of a __strong object. llvm::Value *LvalueDst = Dst.getAddress(); llvm::Value *src = Src.getScalarVal(); #if 0 // FIXME. We cannot positively determine if we have an // 'ivar' assignment, object assignment or an unknown // assignment. For now, generate call to objc_assign_strongCast // assignment which is a safe, but consevative assumption. if (Dst.isObjCIvar()) CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, LvalueDst); else CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst); #endif CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst); return; } assert(Src.isScalar() && "Can't emit an agg store with this method"); EmitStoreOfScalar(Src.getScalarVal(), Dst.getAddress(), Dst.isVolatileQualified()); } void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst, QualType Ty, llvm::Value **Result) { unsigned StartBit = Dst.getBitfieldStartBit(); unsigned BitfieldSize = Dst.getBitfieldSize(); llvm::Value *Ptr = Dst.getBitfieldAddr(); const llvm::Type *EltTy = cast(Ptr->getType())->getElementType(); unsigned EltTySize = CGM.getTargetData().getTypeSizeInBits(EltTy); // Get the new value, cast to the appropriate type and masked to // exactly the size of the bit-field. llvm::Value *SrcVal = Src.getScalarVal(); llvm::Value *NewVal = Builder.CreateIntCast(SrcVal, EltTy, false, "tmp"); llvm::Constant *Mask = llvm::ConstantInt::get(llvm::APInt::getLowBitsSet(EltTySize, BitfieldSize)); NewVal = Builder.CreateAnd(NewVal, Mask, "bf.value"); // Return the new value of the bit-field, if requested. if (Result) { // Cast back to the proper type for result. const llvm::Type *SrcTy = SrcVal->getType(); llvm::Value *SrcTrunc = Builder.CreateIntCast(NewVal, SrcTy, false, "bf.reload.val"); // Sign extend if necessary. if (Dst.isBitfieldSigned()) { unsigned SrcTySize = CGM.getTargetData().getTypeSizeInBits(SrcTy); llvm::Value *ExtraBits = llvm::ConstantInt::get(SrcTy, SrcTySize - BitfieldSize); SrcTrunc = Builder.CreateAShr(Builder.CreateShl(SrcTrunc, ExtraBits), ExtraBits, "bf.reload.sext"); } *Result = SrcTrunc; } // In some cases the bitfield may straddle two memory locations. // Emit the low part first and check to see if the high needs to be // done. unsigned LowBits = std::min(BitfieldSize, EltTySize - StartBit); llvm::Value *LowVal = Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.prev.low"); // Compute the mask for zero-ing the low part of this bitfield. llvm::Constant *InvMask = llvm::ConstantInt::get(~llvm::APInt::getBitsSet(EltTySize, StartBit, StartBit + LowBits)); // Compute the new low part as // LowVal = (LowVal & InvMask) | (NewVal << StartBit), // with the shift of NewVal implicitly stripping the high bits. llvm::Value *NewLowVal = Builder.CreateShl(NewVal, llvm::ConstantInt::get(EltTy, StartBit), "bf.value.lo"); LowVal = Builder.CreateAnd(LowVal, InvMask, "bf.prev.lo.cleared"); LowVal = Builder.CreateOr(LowVal, NewLowVal, "bf.new.lo"); // Write back. Builder.CreateStore(LowVal, Ptr, Dst.isVolatileQualified()); // If the low part doesn't cover the bitfield emit a high part. if (LowBits < BitfieldSize) { unsigned HighBits = BitfieldSize - LowBits; llvm::Value *HighPtr = Builder.CreateGEP(Ptr, llvm::ConstantInt::get(llvm::Type::Int32Ty, 1), "bf.ptr.hi"); llvm::Value *HighVal = Builder.CreateLoad(HighPtr, Dst.isVolatileQualified(), "bf.prev.hi"); // Compute the mask for zero-ing the high part of this bitfield. llvm::Constant *InvMask = llvm::ConstantInt::get(~llvm::APInt::getLowBitsSet(EltTySize, HighBits)); // Compute the new high part as // HighVal = (HighVal & InvMask) | (NewVal lshr LowBits), // where the high bits of NewVal have already been cleared and the // shift stripping the low bits. llvm::Value *NewHighVal = Builder.CreateLShr(NewVal, llvm::ConstantInt::get(EltTy, LowBits), "bf.value.high"); HighVal = Builder.CreateAnd(HighVal, InvMask, "bf.prev.hi.cleared"); HighVal = Builder.CreateOr(HighVal, NewHighVal, "bf.new.hi"); // Write back. Builder.CreateStore(HighVal, HighPtr, Dst.isVolatileQualified()); } } void CodeGenFunction::EmitStoreThroughPropertyRefLValue(RValue Src, LValue Dst, QualType Ty) { EmitObjCPropertySet(Dst.getPropertyRefExpr(), Src); } void CodeGenFunction::EmitStoreThroughKVCRefLValue(RValue Src, LValue Dst, QualType Ty) { EmitObjCPropertySet(Dst.getKVCRefExpr(), Src); } void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst, QualType Ty) { // This access turns into a read/modify/write of the vector. Load the input // value now. llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(), Dst.isVolatileQualified(), "tmp"); const llvm::Constant *Elts = Dst.getExtVectorElts(); llvm::Value *SrcVal = Src.getScalarVal(); if (const VectorType *VTy = Ty->getAsVectorType()) { unsigned NumSrcElts = VTy->getNumElements(); unsigned NumDstElts = cast(Vec->getType())->getNumElements(); if (NumDstElts == NumSrcElts) { // Use shuffle vector is the src and destination are the same number // of elements llvm::SmallVector Mask; for (unsigned i = 0; i != NumSrcElts; ++i) { unsigned InIdx = getAccessedFieldNo(i, Elts); Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx)); } llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size()); Vec = Builder.CreateShuffleVector(SrcVal, llvm::UndefValue::get(Vec->getType()), MaskV, "tmp"); } else if (NumDstElts > NumSrcElts) { // Extended the source vector to the same length and then shuffle it // into the destination. // FIXME: since we're shuffling with undef, can we just use the indices // into that? This could be simpler. llvm::SmallVector ExtMask; unsigned i; for (i = 0; i != NumSrcElts; ++i) ExtMask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, i)); for (; i != NumDstElts; ++i) ExtMask.push_back(llvm::UndefValue::get(llvm::Type::Int32Ty)); llvm::Value *ExtMaskV = llvm::ConstantVector::get(&ExtMask[0], ExtMask.size()); llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal, llvm::UndefValue::get(SrcVal->getType()), ExtMaskV, "tmp"); // build identity llvm::SmallVector Mask; for (unsigned i = 0; i != NumDstElts; ++i) { Mask.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, i)); } // modify when what gets shuffled in for (unsigned i = 0; i != NumSrcElts; ++i) { unsigned Idx = getAccessedFieldNo(i, Elts); Mask[Idx] =llvm::ConstantInt::get(llvm::Type::Int32Ty, i+NumDstElts); } llvm::Value *MaskV = llvm::ConstantVector::get(&Mask[0], Mask.size()); Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV, "tmp"); } else { // We should never shorten the vector assert(0 && "unexpected shorten vector length"); } } else { // If the Src is a scalar (not a vector) it must be updating one element. unsigned InIdx = getAccessedFieldNo(0, Elts); llvm::Value *Elt = llvm::ConstantInt::get(llvm::Type::Int32Ty, InIdx); Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp"); } Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified()); } LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) { const VarDecl *VD = dyn_cast(E->getDecl()); if (VD && (VD->isBlockVarDecl() || isa(VD) || isa(VD))) { LValue LV; if (VD->getStorageClass() == VarDecl::Extern) { LV = LValue::MakeAddr(CGM.GetAddrOfGlobalVar(VD), E->getType().getCVRQualifiers(), getContext().getObjCGCAttrKind(E->getType())); } else { llvm::Value *V = LocalDeclMap[VD]; assert(V && "BlockVarDecl not entered in LocalDeclMap?"); // local variables do not get their gc attribute set. QualType::GCAttrTypes attr = QualType::GCNone; // local static? if (VD->getStorageClass() == VarDecl::Static) attr = getContext().getObjCGCAttrKind(E->getType()); LV = LValue::MakeAddr(V, E->getType().getCVRQualifiers(), attr); } return LV; } else if (VD && VD->isFileVarDecl()) { LValue LV = LValue::MakeAddr(CGM.GetAddrOfGlobalVar(VD), E->getType().getCVRQualifiers(), getContext().getObjCGCAttrKind(E->getType())); return LV; } else if (const FunctionDecl *FD = dyn_cast(E->getDecl())) { return LValue::MakeAddr(CGM.GetAddrOfFunction(FD), E->getType().getCVRQualifiers(), getContext().getObjCGCAttrKind(E->getType())); } else if (const ImplicitParamDecl *IPD = dyn_cast(E->getDecl())) { llvm::Value *V = LocalDeclMap[IPD]; assert(V && "BlockVarDecl not entered in LocalDeclMap?"); return LValue::MakeAddr(V, E->getType().getCVRQualifiers(), getContext().getObjCGCAttrKind(E->getType())); } assert(0 && "Unimp declref"); //an invalid LValue, but the assert will //ensure that this point is never reached. return LValue(); } LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) { // __extension__ doesn't affect lvalue-ness. if (E->getOpcode() == UnaryOperator::Extension) return EmitLValue(E->getSubExpr()); QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType()); switch (E->getOpcode()) { default: assert(0 && "Unknown unary operator lvalue!"); case UnaryOperator::Deref: { QualType T = E->getSubExpr()->getType()->getAsPointerType()->getPointeeType(); return LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()), ExprTy->getAsPointerType()->getPointeeType() .getCVRQualifiers(), getContext().getObjCGCAttrKind(T)); } case UnaryOperator::Real: case UnaryOperator::Imag: LValue LV = EmitLValue(E->getSubExpr()); unsigned Idx = E->getOpcode() == UnaryOperator::Imag; return LValue::MakeAddr(Builder.CreateStructGEP(LV.getAddress(), Idx, "idx"), ExprTy.getCVRQualifiers()); } } LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) { return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E), 0); } LValue CodeGenFunction::EmitPredefinedFunctionName(unsigned Type) { std::string GlobalVarName; switch (Type) { default: assert(0 && "Invalid type"); case PredefinedExpr::Func: GlobalVarName = "__func__."; break; case PredefinedExpr::Function: GlobalVarName = "__FUNCTION__."; break; case PredefinedExpr::PrettyFunction: // FIXME:: Demangle C++ method names GlobalVarName = "__PRETTY_FUNCTION__."; break; } std::string FunctionName; if(const FunctionDecl *FD = dyn_cast(CurFuncDecl)) { FunctionName = CGM.getMangledName(FD); } else { // Just get the mangled name. FunctionName = CurFn->getName(); } GlobalVarName += FunctionName; llvm::Constant *C = CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str()); return LValue::MakeAddr(C, 0); } LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) { switch (E->getIdentType()) { default: return EmitUnsupportedLValue(E, "predefined expression"); case PredefinedExpr::Func: case PredefinedExpr::Function: case PredefinedExpr::PrettyFunction: return EmitPredefinedFunctionName(E->getIdentType()); } } LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) { // The index must always be an integer, which is not an aggregate. Emit it. llvm::Value *Idx = EmitScalarExpr(E->getIdx()); // If the base is a vector type, then we are forming a vector element lvalue // with this subscript. if (E->getBase()->getType()->isVectorType()) { // Emit the vector as an lvalue to get its address. LValue LHS = EmitLValue(E->getBase()); assert(LHS.isSimple() && "Can only subscript lvalue vectors here!"); // FIXME: This should properly sign/zero/extend or truncate Idx to i32. return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType().getCVRQualifiers()); } // The base must be a pointer, which is not an aggregate. Emit it. llvm::Value *Base = EmitScalarExpr(E->getBase()); // Extend or truncate the index type to 32 or 64-bits. QualType IdxTy = E->getIdx()->getType(); bool IdxSigned = IdxTy->isSignedIntegerType(); unsigned IdxBitwidth = cast(Idx->getType())->getBitWidth(); if (IdxBitwidth != LLVMPointerWidth) Idx = Builder.CreateIntCast(Idx, llvm::IntegerType::get(LLVMPointerWidth), IdxSigned, "idxprom"); // We know that the pointer points to a type of the correct size, unless the // size is a VLA. if (const VariableArrayType *VAT = getContext().getAsVariableArrayType(E->getType())) { llvm::Value *VLASize = VLASizeMap[VAT]; Idx = Builder.CreateMul(Idx, VLASize); QualType BaseType = getContext().getBaseElementType(VAT); uint64_t BaseTypeSize = getContext().getTypeSize(BaseType) / 8; Idx = Builder.CreateUDiv(Idx, llvm::ConstantInt::get(Idx->getType(), BaseTypeSize)); } QualType T = E->getBase()->getType(); QualType ExprTy = getContext().getCanonicalType(T); T = T->getAsPointerType()->getPointeeType(); return LValue::MakeAddr(Builder.CreateGEP(Base, Idx, "arrayidx"), ExprTy->getAsPointerType()->getPointeeType().getCVRQualifiers(), getContext().getObjCGCAttrKind(T)); } static llvm::Constant *GenerateConstantVector(llvm::SmallVector &Elts) { llvm::SmallVector CElts; for (unsigned i = 0, e = Elts.size(); i != e; ++i) CElts.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, Elts[i])); return llvm::ConstantVector::get(&CElts[0], CElts.size()); } LValue CodeGenFunction:: EmitExtVectorElementExpr(const ExtVectorElementExpr *E) { // Emit the base vector as an l-value. LValue Base; // ExtVectorElementExpr's base can either be a vector or pointer to vector. if (!E->isArrow()) { assert(E->getBase()->getType()->isVectorType()); Base = EmitLValue(E->getBase()); } else { const PointerType *PT = E->getBase()->getType()->getAsPointerType(); llvm::Value *Ptr = EmitScalarExpr(E->getBase()); Base = LValue::MakeAddr(Ptr, PT->getPointeeType().getCVRQualifiers()); } // Encode the element access list into a vector of unsigned indices. llvm::SmallVector Indices; E->getEncodedElementAccess(Indices); if (Base.isSimple()) { llvm::Constant *CV = GenerateConstantVector(Indices); return LValue::MakeExtVectorElt(Base.getAddress(), CV, Base.getQualifiers()); } assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!"); llvm::Constant *BaseElts = Base.getExtVectorElts(); llvm::SmallVector CElts; for (unsigned i = 0, e = Indices.size(); i != e; ++i) { if (isa(BaseElts)) CElts.push_back(llvm::ConstantInt::get(llvm::Type::Int32Ty, 0)); else CElts.push_back(BaseElts->getOperand(Indices[i])); } llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size()); return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV, Base.getQualifiers()); } LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) { bool isUnion = false; bool isIvar = false; Expr *BaseExpr = E->getBase(); llvm::Value *BaseValue = NULL; unsigned CVRQualifiers=0; // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar. if (E->isArrow()) { BaseValue = EmitScalarExpr(BaseExpr); const PointerType *PTy = cast(getContext().getCanonicalType(BaseExpr->getType())); if (PTy->getPointeeType()->isUnionType()) isUnion = true; CVRQualifiers = PTy->getPointeeType().getCVRQualifiers(); } else if (isa(BaseExpr) || isa(BaseExpr)) { RValue RV = EmitObjCPropertyGet(BaseExpr); BaseValue = RV.getAggregateAddr(); if (BaseExpr->getType()->isUnionType()) isUnion = true; CVRQualifiers = BaseExpr->getType().getCVRQualifiers(); } else { LValue BaseLV = EmitLValue(BaseExpr); if (BaseLV.isObjCIvar()) isIvar = true; // FIXME: this isn't right for bitfields. BaseValue = BaseLV.getAddress(); if (BaseExpr->getType()->isUnionType()) isUnion = true; CVRQualifiers = BaseExpr->getType().getCVRQualifiers(); } FieldDecl *Field = dyn_cast(E->getMemberDecl()); // FIXME: Handle non-field member expressions assert(Field && "No code generation for non-field member references"); LValue MemExpLV = EmitLValueForField(BaseValue, Field, isUnion, CVRQualifiers); LValue::SetObjCIvar(MemExpLV, isIvar); return MemExpLV; } LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue, FieldDecl* Field, unsigned CVRQualifiers) { unsigned idx = CGM.getTypes().getLLVMFieldNo(Field); // FIXME: CodeGenTypes should expose a method to get the appropriate // type for FieldTy (the appropriate type is ABI-dependent). const llvm::Type *FieldTy = CGM.getTypes().ConvertTypeForMem(Field->getType()); const llvm::PointerType *BaseTy = cast(BaseValue->getType()); unsigned AS = BaseTy->getAddressSpace(); BaseValue = Builder.CreateBitCast(BaseValue, llvm::PointerType::get(FieldTy, AS), "tmp"); llvm::Value *V = Builder.CreateGEP(BaseValue, llvm::ConstantInt::get(llvm::Type::Int32Ty, idx), "tmp"); CodeGenTypes::BitFieldInfo bitFieldInfo = CGM.getTypes().getBitFieldInfo(Field); return LValue::MakeBitfield(V, bitFieldInfo.Begin, bitFieldInfo.Size, Field->getType()->isSignedIntegerType(), Field->getType().getCVRQualifiers()|CVRQualifiers); } LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue, FieldDecl* Field, bool isUnion, unsigned CVRQualifiers) { if (Field->isBitField()) return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers); unsigned idx = CGM.getTypes().getLLVMFieldNo(Field); llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp"); // Match union field type. if (isUnion) { const llvm::Type *FieldTy = CGM.getTypes().ConvertTypeForMem(Field->getType()); const llvm::PointerType * BaseTy = cast(BaseValue->getType()); unsigned AS = BaseTy->getAddressSpace(); V = Builder.CreateBitCast(V, llvm::PointerType::get(FieldTy, AS), "tmp"); } QualType::GCAttrTypes attr = QualType::GCNone; if (CGM.getLangOptions().ObjC1 && CGM.getLangOptions().getGCMode() != LangOptions::NonGC) { QualType Ty = Field->getType(); attr = Ty.getObjCGCAttr(); if (attr != QualType::GCNone) { // __weak attribute on a field is ignored. if (attr == QualType::Weak) attr = QualType::GCNone; } else if (getContext().isObjCObjectPointerType(Ty)) attr = QualType::Strong; } LValue LV = LValue::MakeAddr(V, Field->getType().getCVRQualifiers()|CVRQualifiers, attr); return LV; } LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E) { const llvm::Type *LTy = ConvertType(E->getType()); llvm::Value *DeclPtr = CreateTempAlloca(LTy, ".compoundliteral"); const Expr* InitExpr = E->getInitializer(); LValue Result = LValue::MakeAddr(DeclPtr, E->getType().getCVRQualifiers()); if (E->getType()->isComplexType()) { EmitComplexExprIntoAddr(InitExpr, DeclPtr, false); } else if (hasAggregateLLVMType(E->getType())) { EmitAnyExpr(InitExpr, DeclPtr, false); } else { EmitStoreThroughLValue(EmitAnyExpr(InitExpr), Result, E->getType()); } return Result; } //===--------------------------------------------------------------------===// // Expression Emission //===--------------------------------------------------------------------===// RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) { if (const ImplicitCastExpr *IcExpr = dyn_cast(E->getCallee())) if (const DeclRefExpr *DRExpr = dyn_cast(IcExpr->getSubExpr())) if (const FunctionDecl *FDecl = dyn_cast(DRExpr->getDecl())) if (unsigned builtinID = FDecl->getBuiltinID(getContext())) return EmitBuiltinExpr(FDecl, builtinID, E); if (E->getCallee()->getType()->isBlockPointerType()) return EmitBlockCallExpr(E); llvm::Value *Callee = EmitScalarExpr(E->getCallee()); return EmitCallExpr(Callee, E->getCallee()->getType(), E->arg_begin(), E->arg_end()); } RValue CodeGenFunction::EmitCallExpr(Expr *FnExpr, CallExpr::const_arg_iterator ArgBeg, CallExpr::const_arg_iterator ArgEnd) { llvm::Value *Callee = EmitScalarExpr(FnExpr); return EmitCallExpr(Callee, FnExpr->getType(), ArgBeg, ArgEnd); } LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) { // Can only get l-value for binary operator expressions which are a // simple assignment of aggregate type. if (E->getOpcode() != BinaryOperator::Assign) return EmitUnsupportedLValue(E, "binary l-value expression"); llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType())); EmitAggExpr(E, Temp, false); // FIXME: Are these qualifiers correct? return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers(), getContext().getObjCGCAttrKind(E->getType())); } LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) { // Can only get l-value for call expression returning aggregate type RValue RV = EmitCallExpr(E); return LValue::MakeAddr(RV.getAggregateAddr(), E->getType().getCVRQualifiers(), getContext().getObjCGCAttrKind(E->getType())); } LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) { // FIXME: This shouldn't require another copy. llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType())); EmitAggExpr(E, Temp, false); return LValue::MakeAddr(Temp, E->getType().getCVRQualifiers()); } LValue CodeGenFunction::EmitCXXConditionDeclLValue(const CXXConditionDeclExpr *E) { EmitLocalBlockVarDecl(*E->getVarDecl()); return EmitDeclRefLValue(E); } LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) { // Can only get l-value for message expression returning aggregate type RValue RV = EmitObjCMessageExpr(E); // FIXME: can this be volatile? return LValue::MakeAddr(RV.getAggregateAddr(), E->getType().getCVRQualifiers(), getContext().getObjCGCAttrKind(E->getType())); } llvm::Value *CodeGenFunction::EmitIvarOffset(ObjCInterfaceDecl *Interface, const ObjCIvarDecl *Ivar) { // Objective-C objects are traditionally C structures with their layout // defined at compile-time. In some implementations, their layout is not // defined until run time in order to allow instance variables to be added to // a class without recompiling all of the subclasses. If this is the case // then the CGObjCRuntime subclass must return true to LateBoundIvars and // implement the lookup itself. if (CGM.getObjCRuntime().LateBoundIVars()) assert(0 && "late-bound ivars are unsupported"); return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar); } LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy, llvm::Value *BaseValue, const ObjCIvarDecl *Ivar, const FieldDecl *Field, unsigned CVRQualifiers) { // See comment in EmitIvarOffset. if (CGM.getObjCRuntime().LateBoundIVars()) assert(0 && "late-bound ivars are unsupported"); LValue LV = CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue, Ivar, Field, CVRQualifiers); return LV; } LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) { // FIXME: A lot of the code below could be shared with EmitMemberExpr. llvm::Value *BaseValue = 0; const Expr *BaseExpr = E->getBase(); unsigned CVRQualifiers = 0; QualType ObjectTy; if (E->isArrow()) { BaseValue = EmitScalarExpr(BaseExpr); const PointerType *PTy = cast(getContext().getCanonicalType(BaseExpr->getType())); ObjectTy = PTy->getPointeeType(); CVRQualifiers = ObjectTy.getCVRQualifiers(); } else { LValue BaseLV = EmitLValue(BaseExpr); // FIXME: this isn't right for bitfields. BaseValue = BaseLV.getAddress(); ObjectTy = BaseExpr->getType(); CVRQualifiers = ObjectTy.getCVRQualifiers(); } return EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(), getContext().getFieldDecl(E), CVRQualifiers); } LValue CodeGenFunction::EmitObjCPropertyRefLValue(const ObjCPropertyRefExpr *E) { // This is a special l-value that just issues sends when we load or // store through it. return LValue::MakePropertyRef(E, E->getType().getCVRQualifiers()); } LValue CodeGenFunction::EmitObjCKVCRefLValue(const ObjCKVCRefExpr *E) { // This is a special l-value that just issues sends when we load or // store through it. return LValue::MakeKVCRef(E, E->getType().getCVRQualifiers()); } LValue CodeGenFunction::EmitObjCSuperExpr(const ObjCSuperExpr *E) { return EmitUnsupportedLValue(E, "use of super"); } RValue CodeGenFunction::EmitCallExpr(llvm::Value *Callee, QualType CalleeType, CallExpr::const_arg_iterator ArgBeg, CallExpr::const_arg_iterator ArgEnd) { // Get the actual function type. The callee type will always be a // pointer to function type or a block pointer type. QualType ResultType; if (const BlockPointerType *BPT = dyn_cast(CalleeType)) { ResultType = BPT->getPointeeType()->getAsFunctionType()->getResultType(); } else { assert(CalleeType->isFunctionPointerType() && "Call must have function pointer type!"); QualType FnType = CalleeType->getAsPointerType()->getPointeeType(); ResultType = FnType->getAsFunctionType()->getResultType(); } CallArgList Args; for (CallExpr::const_arg_iterator I = ArgBeg; I != ArgEnd; ++I) Args.push_back(std::make_pair(EmitAnyExprToTemp(*I), I->getType())); return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args), Callee, Args); }