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llvm-project/clang/lib/CodeGen/CGExpr.cpp

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//===--- 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 "CGRecordLayout.h"
#include "CGObjCRuntime.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "llvm/Intrinsics.h"
#include "clang/Frontend/CodeGenOptions.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 llvm::Twine &Name) {
if (!Builder.isNamePreserving())
return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt);
}
void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var,
llvm::Value *Init) {
llvm::StoreInst *Store = new llvm::StoreInst(Init, Var);
llvm::BasicBlock *Block = AllocaInsertPt->getParent();
Block->getInstList().insertAfter(&*AllocaInsertPt, Store);
}
llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty,
const llvm::Twine &Name) {
llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name);
// FIXME: Should we prefer the preferred type alignment here?
CharUnits Align = getContext().getTypeAlignInChars(Ty);
Alloc->setAlignment(Align.getQuantity());
return Alloc;
}
llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty,
const llvm::Twine &Name) {
llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name);
// FIXME: Should we prefer the preferred type alignment here?
CharUnits Align = getContext().getTypeAlignInChars(Ty);
Alloc->setAlignment(Align.getQuantity());
return Alloc;
}
/// 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()->isMemberFunctionPointerType()) {
LValue LV = EmitAggExprToLValue(E);
// Get the pointer.
llvm::Value *FuncPtr = Builder.CreateStructGEP(LV.getAddress(), 0,
"src.ptr");
FuncPtr = Builder.CreateLoad(FuncPtr);
llvm::Value *IsNotNull =
Builder.CreateICmpNE(FuncPtr,
llvm::Constant::getNullValue(FuncPtr->getType()),
"tobool");
return IsNotNull;
}
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, bool IgnoreResult,
bool IsInitializer) {
if (!hasAggregateLLVMType(E->getType()))
return RValue::get(EmitScalarExpr(E, IgnoreResult));
else if (E->getType()->isAnyComplexType())
return RValue::getComplex(EmitComplexExpr(E, false, false,
IgnoreResult, IgnoreResult));
EmitAggExpr(E, AggLoc, IsAggLocVolatile, IgnoreResult, IsInitializer);
return RValue::getAggregate(AggLoc, IsAggLocVolatile);
}
/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
/// always be accessible even if no aggregate location is provided.
RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E,
bool IsAggLocVolatile,
bool IsInitializer) {
llvm::Value *AggLoc = 0;
if (hasAggregateLLVMType(E->getType()) &&
!E->getType()->isAnyComplexType())
AggLoc = CreateMemTemp(E->getType(), "agg.tmp");
return EmitAnyExpr(E, AggLoc, IsAggLocVolatile, /*IgnoreResult=*/false,
IsInitializer);
}
/// EmitAnyExprToMem - Evaluate an expression into a given memory
/// location.
void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
llvm::Value *Location,
bool IsLocationVolatile,
bool IsInit) {
if (E->getType()->isComplexType())
EmitComplexExprIntoAddr(E, Location, IsLocationVolatile);
else if (hasAggregateLLVMType(E->getType()))
EmitAggExpr(E, Location, IsLocationVolatile, /*Ignore*/ false, IsInit);
else {
RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
LValue LV = MakeAddrLValue(Location, E->getType());
EmitStoreThroughLValue(RV, LV, E->getType());
}
}
/// \brief An adjustment to be made to the temporary created when emitting a
/// reference binding, which accesses a particular subobject of that temporary.
struct SubobjectAdjustment {
enum { DerivedToBaseAdjustment, FieldAdjustment } Kind;
union {
struct {
const CastExpr *BasePath;
const CXXRecordDecl *DerivedClass;
} DerivedToBase;
FieldDecl *Field;
};
SubobjectAdjustment(const CastExpr *BasePath,
const CXXRecordDecl *DerivedClass)
: Kind(DerivedToBaseAdjustment)
{
DerivedToBase.BasePath = BasePath;
DerivedToBase.DerivedClass = DerivedClass;
}
SubobjectAdjustment(FieldDecl *Field)
: Kind(FieldAdjustment)
{
this->Field = Field;
}
};
static llvm::Value *
CreateReferenceTemporary(CodeGenFunction& CGF, QualType Type,
const NamedDecl *InitializedDecl) {
if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
if (VD->hasGlobalStorage()) {
llvm::SmallString<256> Name;
CGF.CGM.getMangleContext().mangleReferenceTemporary(VD, Name);
const llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type);
// Create the reference temporary.
llvm::GlobalValue *RefTemp =
new llvm::GlobalVariable(CGF.CGM.getModule(),
RefTempTy, /*isConstant=*/false,
llvm::GlobalValue::InternalLinkage,
llvm::Constant::getNullValue(RefTempTy),
Name.str());
return RefTemp;
}
}
return CGF.CreateMemTemp(Type, "ref.tmp");
}
static llvm::Value *
EmitExprForReferenceBinding(CodeGenFunction& CGF, const Expr* E,
llvm::Value *&ReferenceTemporary,
const CXXDestructorDecl *&ReferenceTemporaryDtor,
const NamedDecl *InitializedDecl) {
if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
E = DAE->getExpr();
if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
CodeGenFunction::RunCleanupsScope Scope(CGF);
return EmitExprForReferenceBinding(CGF, TE->getSubExpr(),
ReferenceTemporary,
ReferenceTemporaryDtor,
InitializedDecl);
}
RValue RV;
if (E->isLvalue(CGF.getContext()) == Expr::LV_Valid) {
// Emit the expression as an lvalue.
LValue LV = CGF.EmitLValue(E);
if (LV.isSimple())
return LV.getAddress();
// We have to load the lvalue.
RV = CGF.EmitLoadOfLValue(LV, E->getType());
} else {
QualType ResultTy = E->getType();
llvm::SmallVector<SubobjectAdjustment, 2> Adjustments;
while (true) {
if (const ParenExpr *PE = dyn_cast<ParenExpr>(E)) {
E = PE->getSubExpr();
continue;
}
if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
if ((CE->getCastKind() == CastExpr::CK_DerivedToBase ||
CE->getCastKind() == CastExpr::CK_UncheckedDerivedToBase) &&
E->getType()->isRecordType()) {
E = CE->getSubExpr();
CXXRecordDecl *Derived
= cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
Adjustments.push_back(SubobjectAdjustment(CE, Derived));
continue;
}
if (CE->getCastKind() == CastExpr::CK_NoOp) {
E = CE->getSubExpr();
continue;
}
} else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
if (ME->getBase()->isLvalue(CGF.getContext()) != Expr::LV_Valid &&
ME->getBase()->getType()->isRecordType()) {
if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
E = ME->getBase();
Adjustments.push_back(SubobjectAdjustment(Field));
continue;
}
}
}
// Nothing changed.
break;
}
// Create a reference temporary if necessary.
if (CGF.hasAggregateLLVMType(E->getType()) &&
!E->getType()->isAnyComplexType())
ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
InitializedDecl);
RV = CGF.EmitAnyExpr(E, ReferenceTemporary, /*IsAggLocVolatile=*/false,
/*IgnoreResult=*/false, InitializedDecl);
if (InitializedDecl) {
// Get the destructor for the reference temporary.
if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
if (!ClassDecl->hasTrivialDestructor())
ReferenceTemporaryDtor = ClassDecl->getDestructor();
}
}
// Check if need to perform derived-to-base casts and/or field accesses, to
// get from the temporary object we created (and, potentially, for which we
// extended the lifetime) to the subobject we're binding the reference to.
if (!Adjustments.empty()) {
llvm::Value *Object = RV.getAggregateAddr();
for (unsigned I = Adjustments.size(); I != 0; --I) {
SubobjectAdjustment &Adjustment = Adjustments[I-1];
switch (Adjustment.Kind) {
case SubobjectAdjustment::DerivedToBaseAdjustment:
Object =
CGF.GetAddressOfBaseClass(Object,
Adjustment.DerivedToBase.DerivedClass,
Adjustment.DerivedToBase.BasePath->path_begin(),
Adjustment.DerivedToBase.BasePath->path_end(),
/*NullCheckValue=*/false);
break;
case SubobjectAdjustment::FieldAdjustment: {
LValue LV =
CGF.EmitLValueForField(Object, Adjustment.Field, 0);
if (LV.isSimple()) {
Object = LV.getAddress();
break;
}
// For non-simple lvalues, we actually have to create a copy of
// the object we're binding to.
QualType T = Adjustment.Field->getType().getNonReferenceType()
.getUnqualifiedType();
Object = CreateReferenceTemporary(CGF, T, InitializedDecl);
LValue TempLV = CGF.MakeAddrLValue(Object,
Adjustment.Field->getType());
CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV, T), TempLV, T);
break;
}
}
}
const llvm::Type *ResultPtrTy = CGF.ConvertType(ResultTy)->getPointerTo();
return CGF.Builder.CreateBitCast(Object, ResultPtrTy, "temp");
}
}
if (RV.isAggregate())
return RV.getAggregateAddr();
// Create a temporary variable that we can bind the reference to.
ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
InitializedDecl);
unsigned Alignment =
CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity();
if (RV.isScalar())
CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary,
/*Volatile=*/false, Alignment, E->getType());
else
CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary,
/*Volatile=*/false);
return ReferenceTemporary;
}
RValue
CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
const NamedDecl *InitializedDecl) {
llvm::Value *ReferenceTemporary = 0;
const CXXDestructorDecl *ReferenceTemporaryDtor = 0;
llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary,
ReferenceTemporaryDtor,
InitializedDecl);
if (!ReferenceTemporaryDtor)
return RValue::get(Value);
// Make sure to call the destructor for the reference temporary.
if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
if (VD->hasGlobalStorage()) {
llvm::Constant *DtorFn =
CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete);
CGF.EmitCXXGlobalDtorRegistration(DtorFn,
cast<llvm::Constant>(ReferenceTemporary));
return RValue::get(Value);
}
}
PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary);
return RValue::get(Value);
}
/// 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<llvm::ConstantAggregateZero>(Elts))
return 0;
return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue();
}
void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) {
if (!CatchUndefined)
return;
Address = Builder.CreateBitCast(Address, PtrToInt8Ty);
const llvm::Type *IntPtrT = IntPtrTy;
llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, &IntPtrT, 1);
const llvm::IntegerType *Int1Ty = llvm::Type::getInt1Ty(VMContext);
// In time, people may want to control this and use a 1 here.
llvm::Value *Arg = llvm::ConstantInt::get(Int1Ty, 0);
llvm::Value *C = Builder.CreateCall2(F, Address, Arg);
llvm::BasicBlock *Cont = createBasicBlock();
llvm::BasicBlock *Check = createBasicBlock();
llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL);
Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check);
EmitBlock(Check);
Builder.CreateCondBr(Builder.CreateICmpUGE(C,
llvm::ConstantInt::get(IntPtrTy, Size)),
Cont, getTrapBB());
EmitBlock(Cont);
}
CodeGenFunction::ComplexPairTy CodeGenFunction::
EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
bool isInc, bool isPre) {
ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(),
LV.isVolatileQualified());
llvm::Value *NextVal;
if (isa<llvm::IntegerType>(InVal.first->getType())) {
uint64_t AmountVal = isInc ? 1 : -1;
NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
// Add the inc/dec to the real part.
NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
} else {
QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
if (!isInc)
FVal.changeSign();
NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
// Add the inc/dec to the real part.
NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
}
ComplexPairTy IncVal(NextVal, InVal.second);
// Store the updated result through the lvalue.
StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified());
// If this is a postinc, return the value read from memory, otherwise use the
// updated value.
return isPre ? IncVal : InVal;
}
//===----------------------------------------------------------------------===//
// LValue Expression Emission
//===----------------------------------------------------------------------===//
RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
if (Ty->isVoidType())
return RValue::get(0);
if (const ComplexType *CTy = Ty->getAs<ComplexType>()) {
const llvm::Type *EltTy = ConvertType(CTy->getElementType());
llvm::Value *U = llvm::UndefValue::get(EltTy);
return RValue::getComplex(std::make_pair(U, U));
}
if (hasAggregateLLVMType(Ty)) {
const llvm::Type *LTy = llvm::PointerType::getUnqual(ConvertType(Ty));
return RValue::getAggregate(llvm::UndefValue::get(LTy));
}
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 MakeAddrLValue(llvm::UndefValue::get(Ty), E->getType());
}
LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) {
LValue LV = EmitLValue(E);
if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
EmitCheck(LV.getAddress(), getContext().getTypeSize(E->getType()) / 8);
return LV;
}
/// 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::ObjCSelectorExprClass:
return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
case Expr::ObjCIsaExprClass:
return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
case Expr::BinaryOperatorClass:
return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
case Expr::CompoundAssignOperatorClass:
return EmitCompoundAssignOperatorLValue(cast<CompoundAssignOperator>(E));
case Expr::CallExprClass:
case Expr::CXXMemberCallExprClass:
case Expr::CXXOperatorCallExprClass:
return EmitCallExprLValue(cast<CallExpr>(E));
case Expr::VAArgExprClass:
return EmitVAArgExprLValue(cast<VAArgExpr>(E));
case Expr::DeclRefExprClass:
return EmitDeclRefLValue(cast<DeclRefExpr>(E));
case Expr::ParenExprClass:return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
case Expr::PredefinedExprClass:
return EmitPredefinedLValue(cast<PredefinedExpr>(E));
case Expr::StringLiteralClass:
return EmitStringLiteralLValue(cast<StringLiteral>(E));
case Expr::ObjCEncodeExprClass:
return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
case Expr::BlockDeclRefExprClass:
return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E));
case Expr::CXXTemporaryObjectExprClass:
case Expr::CXXConstructExprClass:
return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
case Expr::CXXBindTemporaryExprClass:
return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
case Expr::CXXExprWithTemporariesClass:
return EmitCXXExprWithTemporariesLValue(cast<CXXExprWithTemporaries>(E));
case Expr::CXXScalarValueInitExprClass:
return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E));
case Expr::CXXDefaultArgExprClass:
return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
case Expr::CXXTypeidExprClass:
return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
case Expr::ObjCMessageExprClass:
return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
case Expr::ObjCIvarRefExprClass:
return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
case Expr::ObjCPropertyRefExprClass:
return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E));
case Expr::ObjCImplicitSetterGetterRefExprClass:
return EmitObjCKVCRefLValue(cast<ObjCImplicitSetterGetterRefExpr>(E));
case Expr::ObjCSuperExprClass:
return EmitObjCSuperExprLValue(cast<ObjCSuperExpr>(E));
case Expr::StmtExprClass:
return EmitStmtExprLValue(cast<StmtExpr>(E));
case Expr::UnaryOperatorClass:
return EmitUnaryOpLValue(cast<UnaryOperator>(E));
case Expr::ArraySubscriptExprClass:
return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
case Expr::ExtVectorElementExprClass:
return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
case Expr::MemberExprClass:
return EmitMemberExpr(cast<MemberExpr>(E));
case Expr::CompoundLiteralExprClass:
return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
case Expr::ConditionalOperatorClass:
return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
case Expr::ChooseExprClass:
return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
case Expr::ImplicitCastExprClass:
case Expr::CStyleCastExprClass:
case Expr::CXXFunctionalCastExprClass:
case Expr::CXXStaticCastExprClass:
case Expr::CXXDynamicCastExprClass:
case Expr::CXXReinterpretCastExprClass:
case Expr::CXXConstCastExprClass:
return EmitCastLValue(cast<CastExpr>(E));
}
}
llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
unsigned Alignment, QualType Ty) {
llvm::LoadInst *Load = Builder.CreateLoad(Addr, "tmp");
if (Volatile)
Load->setVolatile(true);
if (Alignment)
Load->setAlignment(Alignment);
// Bool can have different representation in memory than in registers.
llvm::Value *V = Load;
if (Ty->isBooleanType())
if (V->getType() != llvm::Type::getInt1Ty(VMContext))
V = Builder.CreateTrunc(V, llvm::Type::getInt1Ty(VMContext), "tobool");
return V;
}
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
bool Volatile, unsigned Alignment,
QualType Ty) {
if (Ty->isBooleanType()) {
// Bool can have different representation in memory than in registers.
const llvm::PointerType *DstPtr = cast<llvm::PointerType>(Addr->getType());
Value = Builder.CreateIntCast(Value, DstPtr->getElementType(), false);
}
llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
if (Alignment)
Store->setAlignment(Alignment);
}
/// 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();
return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
AddrWeakObj));
}
if (LV.isSimple()) {
llvm::Value *Ptr = LV.getAddress();
const llvm::Type *EltTy =
cast<llvm::PointerType>(Ptr->getType())->getElementType();
// Simple scalar l-value.
//
// FIXME: We shouldn't have to use isSingleValueType here.
if (EltTy->isSingleValueType())
return RValue::get(EmitLoadOfScalar(Ptr, LV.isVolatileQualified(),
LV.getAlignment(), 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) {
const CGBitFieldInfo &Info = LV.getBitFieldInfo();
// Get the output type.
const llvm::Type *ResLTy = ConvertType(ExprType);
unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
// Compute the result as an OR of all of the individual component accesses.
llvm::Value *Res = 0;
for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
// Get the field pointer.
llvm::Value *Ptr = LV.getBitFieldBaseAddr();
// Only offset by the field index if used, so that incoming values are not
// required to be structures.
if (AI.FieldIndex)
Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
// Offset by the byte offset, if used.
if (AI.FieldByteOffset) {
const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
Ptr = Builder.CreateBitCast(Ptr, i8PTy);
Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
}
// Cast to the access type.
const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
ExprType.getAddressSpace());
Ptr = Builder.CreateBitCast(Ptr, PTy);
// Perform the load.
llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
if (AI.AccessAlignment)
Load->setAlignment(AI.AccessAlignment);
// Shift out unused low bits and mask out unused high bits.
llvm::Value *Val = Load;
if (AI.FieldBitStart)
Val = Builder.CreateLShr(Load, AI.FieldBitStart);
Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth,
AI.TargetBitWidth),
"bf.clear");
// Extend or truncate to the target size.
if (AI.AccessWidth < ResSizeInBits)
Val = Builder.CreateZExt(Val, ResLTy);
else if (AI.AccessWidth > ResSizeInBits)
Val = Builder.CreateTrunc(Val, ResLTy);
// Shift into place, and OR into the result.
if (AI.TargetBitOffset)
Val = Builder.CreateShl(Val, AI.TargetBitOffset);
Res = Res ? Builder.CreateOr(Res, Val) : Val;
}
// If the bit-field is signed, perform the sign-extension.
//
// FIXME: This can easily be folded into the load of the high bits, which
// could also eliminate the mask of high bits in some situations.
if (Info.isSigned()) {
unsigned ExtraBits = ResSizeInBits - Info.getSize();
if (ExtraBits)
Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits),
ExtraBits, "bf.val.sext");
}
return RValue::get(Res);
}
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->getAs<VectorType>();
if (!ExprVT) {
unsigned InIdx = getAccessedFieldNo(0, Elts);
llvm::Value *Elt = llvm::ConstantInt::get(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<llvm::Constant*, 4> Mask;
for (unsigned i = 0; i != NumResultElts; ++i) {
unsigned InIdx = getAccessedFieldNo(i, Elts);
Mask.push_back(llvm::ConstantInt::get(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);
assert(Dst.isKVCRef() && "Unknown LValue type");
return EmitStoreThroughKVCRefLValue(Src, Dst, Ty);
}
if (Dst.isObjCWeak() && !Dst.isNonGC()) {
// 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() && !Dst.isNonGC()) {
// load of a __strong object.
llvm::Value *LvalueDst = Dst.getAddress();
llvm::Value *src = Src.getScalarVal();
if (Dst.isObjCIvar()) {
assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
const llvm::Type *ResultType = ConvertType(getContext().LongTy);
llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
llvm::Value *dst = RHS;
RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
llvm::Value *LHS =
Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
BytesBetween);
} else if (Dst.isGlobalObjCRef()) {
CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
Dst.isThreadLocalRef());
}
else
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(), Dst.getAlignment(), Ty);
}
void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
QualType Ty,
llvm::Value **Result) {
const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
// Get the output type.
const llvm::Type *ResLTy = ConvertTypeForMem(Ty);
unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
// Get the source value, truncated to the width of the bit-field.
llvm::Value *SrcVal = Src.getScalarVal();
if (Ty->isBooleanType())
SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false);
SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits,
Info.getSize()),
"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 = Src.getScalarVal()->getType();
llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false,
"bf.reload.val");
// Sign extend if necessary.
if (Info.isSigned()) {
unsigned ExtraBits = ResSizeInBits - Info.getSize();
if (ExtraBits)
ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits),
ExtraBits, "bf.reload.sext");
}
*Result = ReloadVal;
}
// Iterate over the components, writing each piece to memory.
for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) {
const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i);
// Get the field pointer.
llvm::Value *Ptr = Dst.getBitFieldBaseAddr();
// Only offset by the field index if used, so that incoming values are not
// required to be structures.
if (AI.FieldIndex)
Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field");
// Offset by the byte offset, if used.
if (AI.FieldByteOffset) {
const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
Ptr = Builder.CreateBitCast(Ptr, i8PTy);
Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset,"bf.field.offs");
}
// Cast to the access type.
const llvm::Type *PTy = llvm::Type::getIntNPtrTy(VMContext, AI.AccessWidth,
Ty.getAddressSpace());
Ptr = Builder.CreateBitCast(Ptr, PTy);
// Extract the piece of the bit-field value to write in this access, limited
// to the values that are part of this access.
llvm::Value *Val = SrcVal;
if (AI.TargetBitOffset)
Val = Builder.CreateLShr(Val, AI.TargetBitOffset);
Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits,
AI.TargetBitWidth));
// Extend or truncate to the access size.
const llvm::Type *AccessLTy =
llvm::Type::getIntNTy(VMContext, AI.AccessWidth);
if (ResSizeInBits < AI.AccessWidth)
Val = Builder.CreateZExt(Val, AccessLTy);
else if (ResSizeInBits > AI.AccessWidth)
Val = Builder.CreateTrunc(Val, AccessLTy);
// Shift into the position in memory.
if (AI.FieldBitStart)
Val = Builder.CreateShl(Val, AI.FieldBitStart);
// If necessary, load and OR in bits that are outside of the bit-field.
if (AI.TargetBitWidth != AI.AccessWidth) {
llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified());
if (AI.AccessAlignment)
Load->setAlignment(AI.AccessAlignment);
// Compute the mask for zeroing the bits that are part of the bit-field.
llvm::APInt InvMask =
~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart,
AI.FieldBitStart + AI.TargetBitWidth);
// Apply the mask and OR in to the value to write.
Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val);
}
// Write the value.
llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr,
Dst.isVolatileQualified());
if (AI.AccessAlignment)
Store->setAlignment(AI.AccessAlignment);
}
}
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->getAs<VectorType>()) {
unsigned NumSrcElts = VTy->getNumElements();
unsigned NumDstElts =
cast<llvm::VectorType>(Vec->getType())->getNumElements();
if (NumDstElts == NumSrcElts) {
// Use shuffle vector is the src and destination are the same number of
// elements and restore the vector mask since it is on the side it will be
// stored.
llvm::SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
for (unsigned i = 0; i != NumSrcElts; ++i) {
unsigned InIdx = getAccessedFieldNo(i, Elts);
Mask[InIdx] = llvm::ConstantInt::get(Int32Ty, i);
}
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<llvm::Constant*, 4> ExtMask;
unsigned i;
for (i = 0; i != NumSrcElts; ++i)
ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i));
for (; i != NumDstElts; ++i)
ExtMask.push_back(llvm::UndefValue::get(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<llvm::Constant*, 4> Mask;
for (unsigned i = 0; i != NumDstElts; ++i)
Mask.push_back(llvm::ConstantInt::get(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(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(Int32Ty, InIdx);
Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt, "tmp");
}
Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified());
}
// setObjCGCLValueClass - sets class of he lvalue for the purpose of
// generating write-barries API. It is currently a global, ivar,
// or neither.
static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
LValue &LV) {
if (Ctx.getLangOptions().getGCMode() == LangOptions::NonGC)
return;
if (isa<ObjCIvarRefExpr>(E)) {
LV.setObjCIvar(true);
ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
LV.setBaseIvarExp(Exp->getBase());
LV.setObjCArray(E->getType()->isArrayType());
return;
}
if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) {
if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
if ((VD->isBlockVarDecl() && !VD->hasLocalStorage()) ||
VD->isFileVarDecl()) {
LV.setGlobalObjCRef(true);
LV.setThreadLocalRef(VD->isThreadSpecified());
}
}
LV.setObjCArray(E->getType()->isArrayType());
return;
}
if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
return;
}
if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
if (LV.isObjCIvar()) {
// If cast is to a structure pointer, follow gcc's behavior and make it
// a non-ivar write-barrier.
QualType ExpTy = E->getType();
if (ExpTy->isPointerType())
ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
if (ExpTy->isRecordType())
LV.setObjCIvar(false);
}
return;
}
if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
return;
}
if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV);
return;
}
if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
if (LV.isObjCIvar() && !LV.isObjCArray())
// Using array syntax to assigning to what an ivar points to is not
// same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
LV.setObjCIvar(false);
else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
// Using array syntax to assigning to what global points to is not
// same as assigning to the global itself. {id *G;} G[i] = 0;
LV.setGlobalObjCRef(false);
return;
}
if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
// We don't know if member is an 'ivar', but this flag is looked at
// only in the context of LV.isObjCIvar().
LV.setObjCArray(E->getType()->isArrayType());
return;
}
}
static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
const Expr *E, const VarDecl *VD) {
assert((VD->hasExternalStorage() || VD->isFileVarDecl()) &&
"Var decl must have external storage or be a file var decl!");
llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
if (VD->getType()->isReferenceType())
V = CGF.Builder.CreateLoad(V, "tmp");
unsigned Alignment = CGF.getContext().getDeclAlign(VD).getQuantity();
LValue LV = CGF.MakeAddrLValue(V, E->getType(), Alignment);
setObjCGCLValueClass(CGF.getContext(), E, LV);
return LV;
}
static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
const Expr *E, const FunctionDecl *FD) {
llvm::Value* V = CGF.CGM.GetAddrOfFunction(FD);
if (!FD->hasPrototype()) {
if (const FunctionProtoType *Proto =
FD->getType()->getAs<FunctionProtoType>()) {
// Ugly case: for a K&R-style definition, the type of the definition
// isn't the same as the type of a use. Correct for this with a
// bitcast.
QualType NoProtoType =
CGF.getContext().getFunctionNoProtoType(Proto->getResultType());
NoProtoType = CGF.getContext().getPointerType(NoProtoType);
V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType), "tmp");
}
}
unsigned Alignment = CGF.getContext().getDeclAlign(FD).getQuantity();
return CGF.MakeAddrLValue(V, E->getType(), Alignment);
}
LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
const NamedDecl *ND = E->getDecl();
unsigned Alignment = CGF.getContext().getDeclAlign(ND).getQuantity();
if (ND->hasAttr<WeakRefAttr>()) {
const ValueDecl* VD = cast<ValueDecl>(ND);
llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD);
return MakeAddrLValue(Aliasee, E->getType(), Alignment);
}
if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
// Check if this is a global variable.
if (VD->hasExternalStorage() || VD->isFileVarDecl())
return EmitGlobalVarDeclLValue(*this, E, VD);
bool NonGCable = VD->hasLocalStorage() && !VD->hasAttr<BlocksAttr>();
llvm::Value *V = LocalDeclMap[VD];
if (!V && getContext().getLangOptions().CPlusPlus &&
VD->isStaticLocal())
V = CGM.getStaticLocalDeclAddress(VD);
assert(V && "DeclRefExpr not entered in LocalDeclMap?");
if (VD->hasAttr<BlocksAttr>()) {
V = Builder.CreateStructGEP(V, 1, "forwarding");
V = Builder.CreateLoad(V);
V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
VD->getNameAsString());
}
if (VD->getType()->isReferenceType())
V = Builder.CreateLoad(V, "tmp");
LValue LV = MakeAddrLValue(V, E->getType(), Alignment);
if (NonGCable) {
LV.getQuals().removeObjCGCAttr();
LV.setNonGC(true);
}
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
return EmitFunctionDeclLValue(*this, E, FD);
// FIXME: the qualifier check does not seem sufficient here
if (E->getQualifier()) {
const FieldDecl *FD = cast<FieldDecl>(ND);
llvm::Value *V = CGM.EmitPointerToDataMember(FD);
return MakeAddrLValue(V, FD->getType(), Alignment);
}
assert(false && "Unhandled DeclRefExpr");
// an invalid LValue, but the assert will
// ensure that this point is never reached.
return LValue();
}
LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
unsigned Alignment =
CGF.getContext().getDeclAlign(E->getDecl()).getQuantity();
return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment);
}
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()->getPointeeType();
assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
LValue LV = MakeAddrLValue(EmitScalarExpr(E->getSubExpr()), T);
LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
// We should not generate __weak write barrier on indirect reference
// of a pointer to object; as in void foo (__weak id *param); *param = 0;
// But, we continue to generate __strong write barrier on indirect write
// into a pointer to object.
if (getContext().getLangOptions().ObjC1 &&
getContext().getLangOptions().getGCMode() != LangOptions::NonGC &&
LV.isObjCWeak())
LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
return LV;
}
case UnaryOperator::Real:
case UnaryOperator::Imag: {
LValue LV = EmitLValue(E->getSubExpr());
unsigned Idx = E->getOpcode() == UnaryOperator::Imag;
return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(),
Idx, "idx"),
ExprTy);
}
case UnaryOperator::PreInc:
case UnaryOperator::PreDec: {
LValue LV = EmitLValue(E->getSubExpr());
bool isInc = E->getOpcode() == UnaryOperator::PreInc;
if (E->getType()->isAnyComplexType())
EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
else
EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
return LV;
}
}
}
LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
E->getType());
}
LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
E->getType());
}
LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
switch (E->getIdentType()) {
default:
return EmitUnsupportedLValue(E, "predefined expression");
case PredefinedExpr::Func:
case PredefinedExpr::Function:
case PredefinedExpr::PrettyFunction: {
unsigned Type = E->getIdentType();
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:
GlobalVarName = "__PRETTY_FUNCTION__.";
break;
}
llvm::StringRef FnName = CurFn->getName();
if (FnName.startswith("\01"))
FnName = FnName.substr(1);
GlobalVarName += FnName;
const Decl *CurDecl = CurCodeDecl;
if (CurDecl == 0)
CurDecl = getContext().getTranslationUnitDecl();
std::string FunctionName =
PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl);
llvm::Constant *C =
CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
return MakeAddrLValue(C, E->getType());
}
}
}
llvm::BasicBlock *CodeGenFunction::getTrapBB() {
const CodeGenOptions &GCO = CGM.getCodeGenOpts();
// If we are not optimzing, don't collapse all calls to trap in the function
// to the same call, that way, in the debugger they can see which operation
// did in fact fail. If we are optimizing, we collapse all calls to trap down
// to just one per function to save on codesize.
if (GCO.OptimizationLevel && TrapBB)
return TrapBB;
llvm::BasicBlock *Cont = 0;
if (HaveInsertPoint()) {
Cont = createBasicBlock("cont");
EmitBranch(Cont);
}
TrapBB = createBasicBlock("trap");
EmitBlock(TrapBB);
llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap, 0, 0);
llvm::CallInst *TrapCall = Builder.CreateCall(F);
TrapCall->setDoesNotReturn();
TrapCall->setDoesNotThrow();
Builder.CreateUnreachable();
if (Cont)
EmitBlock(Cont);
return TrapBB;
}
/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
/// array to pointer, return the array subexpression.
static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
// If this isn't just an array->pointer decay, bail out.
const CastExpr *CE = dyn_cast<CastExpr>(E);
if (CE == 0 || CE->getCastKind() != CastExpr::CK_ArrayToPointerDecay)
return 0;
// If this is a decay from variable width array, bail out.
const Expr *SubExpr = CE->getSubExpr();
if (SubExpr->getType()->isVariableArrayType())
return 0;
return SubExpr;
}
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());
QualType IdxTy = E->getIdx()->getType();
bool IdxSigned = IdxTy->isSignedIntegerType();
// 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!");
Idx = Builder.CreateIntCast(Idx, CGF.Int32Ty, IdxSigned, "vidx");
return LValue::MakeVectorElt(LHS.getAddress(), Idx,
E->getBase()->getType().getCVRQualifiers());
}
// Extend or truncate the index type to 32 or 64-bits.
if (!Idx->getType()->isIntegerTy(LLVMPointerWidth))
Idx = Builder.CreateIntCast(Idx, IntPtrTy,
IdxSigned, "idxprom");
// FIXME: As llvm implements the object size checking, this can come out.
if (CatchUndefined) {
if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) {
if (ICE->getCastKind() == CastExpr::CK_ArrayToPointerDecay) {
if (const ConstantArrayType *CAT
= getContext().getAsConstantArrayType(DRE->getType())) {
llvm::APInt Size = CAT->getSize();
llvm::BasicBlock *Cont = createBasicBlock("cont");
Builder.CreateCondBr(Builder.CreateICmpULE(Idx,
llvm::ConstantInt::get(Idx->getType(), Size)),
Cont, getTrapBB());
EmitBlock(Cont);
}
}
}
}
}
// We know that the pointer points to a type of the correct size, unless the
// size is a VLA or Objective-C interface.
llvm::Value *Address = 0;
if (const VariableArrayType *VAT =
getContext().getAsVariableArrayType(E->getType())) {
llvm::Value *VLASize = GetVLASize(VAT);
Idx = Builder.CreateMul(Idx, VLASize);
QualType BaseType = getContext().getBaseElementType(VAT);
CharUnits BaseTypeSize = getContext().getTypeSizeInChars(BaseType);
Idx = Builder.CreateUDiv(Idx,
llvm::ConstantInt::get(Idx->getType(),
BaseTypeSize.getQuantity()));
// The base must be a pointer, which is not an aggregate. Emit it.
llvm::Value *Base = EmitScalarExpr(E->getBase());
Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
} else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
// Indexing over an interface, as in "NSString *P; P[4];"
llvm::Value *InterfaceSize =
llvm::ConstantInt::get(Idx->getType(),
getContext().getTypeSizeInChars(OIT).getQuantity());
Idx = Builder.CreateMul(Idx, InterfaceSize);
const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
// The base must be a pointer, which is not an aggregate. Emit it.
llvm::Value *Base = EmitScalarExpr(E->getBase());
Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
Idx, "arrayidx");
Address = Builder.CreateBitCast(Address, Base->getType());
} else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
// If this is A[i] where A is an array, the frontend will have decayed the
// base to be a ArrayToPointerDecay implicit cast. While correct, it is
// inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
// "gep x, i" here. Emit one "gep A, 0, i".
assert(Array->getType()->isArrayType() &&
"Array to pointer decay must have array source type!");
llvm::Value *ArrayPtr = EmitLValue(Array).getAddress();
llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
llvm::Value *Args[] = { Zero, Idx };
Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, Args+2, "arrayidx");
} else {
// The base must be a pointer, which is not an aggregate. Emit it.
llvm::Value *Base = EmitScalarExpr(E->getBase());
Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
}
QualType T = E->getBase()->getType()->getPointeeType();
assert(!T.isNull() &&
"CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
LValue LV = MakeAddrLValue(Address, T);
LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace());
if (getContext().getLangOptions().ObjC1 &&
getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
setObjCGCLValueClass(getContext(), E, LV);
}
return LV;
}
static
llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
llvm::SmallVector<unsigned, 4> &Elts) {
llvm::SmallVector<llvm::Constant*, 4> CElts;
const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
for (unsigned i = 0, e = Elts.size(); i != e; ++i)
CElts.push_back(llvm::ConstantInt::get(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()) {
// If it is a pointer to a vector, emit the address and form an lvalue with
// it.
llvm::Value *Ptr = EmitScalarExpr(E->getBase());
const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
Base = MakeAddrLValue(Ptr, PT->getPointeeType());
Base.getQuals().removeObjCGCAttr();
} else if (E->getBase()->isLvalue(getContext()) == Expr::LV_Valid) {
// Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
// emit the base as an lvalue.
assert(E->getBase()->getType()->isVectorType());
Base = EmitLValue(E->getBase());
} else {
// Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
assert(E->getBase()->getType()->getAs<VectorType>() &&
"Result must be a vector");
llvm::Value *Vec = EmitScalarExpr(E->getBase());
// Store the vector to memory (because LValue wants an address).
llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType());
Builder.CreateStore(Vec, VecMem);
Base = MakeAddrLValue(VecMem, E->getBase()->getType());
}
// Encode the element access list into a vector of unsigned indices.
llvm::SmallVector<unsigned, 4> Indices;
E->getEncodedElementAccess(Indices);
if (Base.isSimple()) {
llvm::Constant *CV = GenerateConstantVector(VMContext, Indices);
return LValue::MakeExtVectorElt(Base.getAddress(), CV,
Base.getVRQualifiers());
}
assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
llvm::Constant *BaseElts = Base.getExtVectorElts();
llvm::SmallVector<llvm::Constant *, 4> CElts;
for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
if (isa<llvm::ConstantAggregateZero>(BaseElts))
CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0));
else
CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i])));
}
llvm::Constant *CV = llvm::ConstantVector::get(&CElts[0], CElts.size());
return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV,
Base.getVRQualifiers());
}
LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
bool isNonGC = false;
Expr *BaseExpr = E->getBase();
llvm::Value *BaseValue = NULL;
Qualifiers BaseQuals;
// 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 =
BaseExpr->getType()->getAs<PointerType>();
BaseQuals = PTy->getPointeeType().getQualifiers();
} else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
isa<ObjCImplicitSetterGetterRefExpr>(
BaseExpr->IgnoreParens())) {
RValue RV = EmitObjCPropertyGet(BaseExpr);
BaseValue = RV.getAggregateAddr();
BaseQuals = BaseExpr->getType().getQualifiers();
} else {
LValue BaseLV = EmitLValue(BaseExpr);
if (BaseLV.isNonGC())
isNonGC = true;
// FIXME: this isn't right for bitfields.
BaseValue = BaseLV.getAddress();
QualType BaseTy = BaseExpr->getType();
BaseQuals = BaseTy.getQualifiers();
}
NamedDecl *ND = E->getMemberDecl();
if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
LValue LV = EmitLValueForField(BaseValue, Field,
BaseQuals.getCVRQualifiers());
LV.setNonGC(isNonGC);
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
if (VarDecl *VD = dyn_cast<VarDecl>(ND))
return EmitGlobalVarDeclLValue(*this, E, VD);
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND))
return EmitFunctionDeclLValue(*this, E, FD);
assert(false && "Unhandled member declaration!");
return LValue();
}
LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
const FieldDecl* Field,
unsigned CVRQualifiers) {
const CGRecordLayout &RL =
CGM.getTypes().getCGRecordLayout(Field->getParent());
const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
return LValue::MakeBitfield(BaseValue, Info,
Field->getType().getCVRQualifiers()|CVRQualifiers);
}
/// EmitLValueForAnonRecordField - Given that the field is a member of
/// an anonymous struct or union buried inside a record, and given
/// that the base value is a pointer to the enclosing record, derive
/// an lvalue for the ultimate field.
LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue,
const FieldDecl *Field,
unsigned CVRQualifiers) {
llvm::SmallVector<const FieldDecl *, 8> Path;
Path.push_back(Field);
while (Field->getParent()->isAnonymousStructOrUnion()) {
const ValueDecl *VD = Field->getParent()->getAnonymousStructOrUnionObject();
if (!isa<FieldDecl>(VD)) break;
Field = cast<FieldDecl>(VD);
Path.push_back(Field);
}
llvm::SmallVectorImpl<const FieldDecl*>::reverse_iterator
I = Path.rbegin(), E = Path.rend();
while (true) {
LValue LV = EmitLValueForField(BaseValue, *I, CVRQualifiers);
if (++I == E) return LV;
assert(LV.isSimple());
BaseValue = LV.getAddress();
CVRQualifiers |= LV.getVRQualifiers();
}
}
LValue CodeGenFunction::EmitLValueForField(llvm::Value* BaseValue,
const FieldDecl* Field,
unsigned CVRQualifiers) {
if (Field->isBitField())
return EmitLValueForBitfield(BaseValue, Field, CVRQualifiers);
const CGRecordLayout &RL =
CGM.getTypes().getCGRecordLayout(Field->getParent());
unsigned idx = RL.getLLVMFieldNo(Field);
llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
// Match union field type.
if (Field->getParent()->isUnion()) {
const llvm::Type *FieldTy =
CGM.getTypes().ConvertTypeForMem(Field->getType());
const llvm::PointerType * BaseTy =
cast<llvm::PointerType>(BaseValue->getType());
unsigned AS = BaseTy->getAddressSpace();
V = Builder.CreateBitCast(V,
llvm::PointerType::get(FieldTy, AS),
"tmp");
}
if (Field->getType()->isReferenceType())
V = Builder.CreateLoad(V, "tmp");
unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
LValue LV = MakeAddrLValue(V, Field->getType(), Alignment);
LV.getQuals().addCVRQualifiers(CVRQualifiers);
// __weak attribute on a field is ignored.
if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
LV.getQuals().removeObjCGCAttr();
return LV;
}
LValue
CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value* BaseValue,
const FieldDecl* Field,
unsigned CVRQualifiers) {
QualType FieldType = Field->getType();
if (!FieldType->isReferenceType())
return EmitLValueForField(BaseValue, Field, CVRQualifiers);
const CGRecordLayout &RL =
CGM.getTypes().getCGRecordLayout(Field->getParent());
unsigned idx = RL.getLLVMFieldNo(Field);
llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx, "tmp");
assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
unsigned Alignment = getContext().getDeclAlign(Field).getQuantity();
return MakeAddrLValue(V, FieldType, Alignment);
}
LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr* E){
llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
const Expr* InitExpr = E->getInitializer();
LValue Result = MakeAddrLValue(DeclPtr, E->getType());
EmitAnyExprToMem(InitExpr, DeclPtr, /*Volatile*/ false);
return Result;
}
LValue
CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator* E) {
if (E->isLvalue(getContext()) == Expr::LV_Valid) {
if (int Cond = ConstantFoldsToSimpleInteger(E->getCond())) {
Expr *Live = Cond == 1 ? E->getLHS() : E->getRHS();
if (Live)
return EmitLValue(Live);
}
if (!E->getLHS())
return EmitUnsupportedLValue(E, "conditional operator with missing LHS");
llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock);
// Any temporaries created here are conditional.
BeginConditionalBranch();
EmitBlock(LHSBlock);
LValue LHS = EmitLValue(E->getLHS());
EndConditionalBranch();
if (!LHS.isSimple())
return EmitUnsupportedLValue(E, "conditional operator");
// FIXME: We shouldn't need an alloca for this.
llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
Builder.CreateStore(LHS.getAddress(), Temp);
EmitBranch(ContBlock);
// Any temporaries created here are conditional.
BeginConditionalBranch();
EmitBlock(RHSBlock);
LValue RHS = EmitLValue(E->getRHS());
EndConditionalBranch();
if (!RHS.isSimple())
return EmitUnsupportedLValue(E, "conditional operator");
Builder.CreateStore(RHS.getAddress(), Temp);
EmitBranch(ContBlock);
EmitBlock(ContBlock);
Temp = Builder.CreateLoad(Temp, "lv");
return MakeAddrLValue(Temp, E->getType());
}
// ?: here should be an aggregate.
assert((hasAggregateLLVMType(E->getType()) &&
!E->getType()->isAnyComplexType()) &&
"Unexpected conditional operator!");
return EmitAggExprToLValue(E);
}
/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast.
/// If the cast is a dynamic_cast, we can have the usual lvalue result,
/// otherwise if a cast is needed by the code generator in an lvalue context,
/// then it must mean that we need the address of an aggregate in order to
/// access one of its fields. This can happen for all the reasons that casts
/// are permitted with aggregate result, including noop aggregate casts, and
/// cast from scalar to union.
LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
switch (E->getCastKind()) {
case CastExpr::CK_ToVoid:
return EmitUnsupportedLValue(E, "unexpected cast lvalue");
case CastExpr::CK_NoOp:
if (E->getSubExpr()->Classify(getContext()).getKind()
!= Expr::Classification::CL_PRValue) {
LValue LV = EmitLValue(E->getSubExpr());
if (LV.isPropertyRef()) {
QualType QT = E->getSubExpr()->getType();
RValue RV = EmitLoadOfPropertyRefLValue(LV, QT);
assert(!RV.isScalar() && "EmitCastLValue-scalar cast of property ref");
llvm::Value *V = RV.getAggregateAddr();
return MakeAddrLValue(V, QT);
}
return LV;
}
// Fall through to synthesize a temporary.
case CastExpr::CK_Unknown:
case CastExpr::CK_BitCast:
case CastExpr::CK_ArrayToPointerDecay:
case CastExpr::CK_FunctionToPointerDecay:
case CastExpr::CK_NullToMemberPointer:
case CastExpr::CK_IntegralToPointer:
case CastExpr::CK_PointerToIntegral:
case CastExpr::CK_VectorSplat:
case CastExpr::CK_IntegralCast:
case CastExpr::CK_IntegralToFloating:
case CastExpr::CK_FloatingToIntegral:
case CastExpr::CK_FloatingCast:
case CastExpr::CK_DerivedToBaseMemberPointer:
case CastExpr::CK_BaseToDerivedMemberPointer:
case CastExpr::CK_MemberPointerToBoolean:
case CastExpr::CK_AnyPointerToBlockPointerCast: {
// These casts only produce lvalues when we're binding a reference to a
// temporary realized from a (converted) pure rvalue. Emit the expression
// as a value, copy it into a temporary, and return an lvalue referring to
// that temporary.
llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp");
EmitAnyExprToMem(E, V, false, false);
return MakeAddrLValue(V, E->getType());
}
case CastExpr::CK_Dynamic: {
LValue LV = EmitLValue(E->getSubExpr());
llvm::Value *V = LV.getAddress();
const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E);
return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType());
}
case CastExpr::CK_ConstructorConversion:
case CastExpr::CK_UserDefinedConversion:
case CastExpr::CK_AnyPointerToObjCPointerCast:
return EmitLValue(E->getSubExpr());
case CastExpr::CK_UncheckedDerivedToBase:
case CastExpr::CK_DerivedToBase: {
const RecordType *DerivedClassTy =
E->getSubExpr()->getType()->getAs<RecordType>();
CXXRecordDecl *DerivedClassDecl =
cast<CXXRecordDecl>(DerivedClassTy->getDecl());
LValue LV = EmitLValue(E->getSubExpr());
llvm::Value *This;
if (LV.isPropertyRef()) {
RValue RV = EmitLoadOfPropertyRefLValue(LV, E->getSubExpr()->getType());
assert (!RV.isScalar() && "EmitCastLValue");
This = RV.getAggregateAddr();
}
else
This = LV.getAddress();
// Perform the derived-to-base conversion
llvm::Value *Base =
GetAddressOfBaseClass(This, DerivedClassDecl,
E->path_begin(), E->path_end(),
/*NullCheckValue=*/false);
return MakeAddrLValue(Base, E->getType());
}
case CastExpr::CK_ToUnion:
return EmitAggExprToLValue(E);
case CastExpr::CK_BaseToDerived: {
const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
CXXRecordDecl *DerivedClassDecl =
cast<CXXRecordDecl>(DerivedClassTy->getDecl());
LValue LV = EmitLValue(E->getSubExpr());
// Perform the base-to-derived conversion
llvm::Value *Derived =
GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
E->path_begin(), E->path_end(),
/*NullCheckValue=*/false);
return MakeAddrLValue(Derived, E->getType());
}
case CastExpr::CK_LValueBitCast: {
// This must be a reinterpret_cast (or c-style equivalent).
const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E);
LValue LV = EmitLValue(E->getSubExpr());
llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
ConvertType(CE->getTypeAsWritten()));
return MakeAddrLValue(V, E->getType());
}
case CastExpr::CK_ObjCObjectLValueCast: {
LValue LV = EmitLValue(E->getSubExpr());
QualType ToType = getContext().getLValueReferenceType(E->getType());
llvm::Value *V = Builder.CreateBitCast(LV.getAddress(),
ConvertType(ToType));
return MakeAddrLValue(V, E->getType());
}
}
llvm_unreachable("Unhandled lvalue cast kind?");
}
LValue CodeGenFunction::EmitNullInitializationLValue(
const CXXScalarValueInitExpr *E) {
QualType Ty = E->getType();
LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty);
EmitNullInitialization(LV.getAddress(), Ty);
return LV;
}
//===--------------------------------------------------------------------===//
// Expression Emission
//===--------------------------------------------------------------------===//
RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
ReturnValueSlot ReturnValue) {
// Builtins never have block type.
if (E->getCallee()->getType()->isBlockPointerType())
return EmitBlockCallExpr(E, ReturnValue);
if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
return EmitCXXMemberCallExpr(CE, ReturnValue);
const Decl *TargetDecl = 0;
if (const ImplicitCastExpr *CE = dyn_cast<ImplicitCastExpr>(E->getCallee())) {
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(CE->getSubExpr())) {
TargetDecl = DRE->getDecl();
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(TargetDecl))
if (unsigned builtinID = FD->getBuiltinID())
return EmitBuiltinExpr(FD, builtinID, E);
}
}
if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E))
if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
if (isa<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
// C++ [expr.pseudo]p1:
// The result shall only be used as the operand for the function call
// operator (), and the result of such a call has type void. The only
// effect is the evaluation of the postfix-expression before the dot or
// arrow.
EmitScalarExpr(E->getCallee());
return RValue::get(0);
}
llvm::Value *Callee = EmitScalarExpr(E->getCallee());
return EmitCall(E->getCallee()->getType(), Callee, ReturnValue,
E->arg_begin(), E->arg_end(), TargetDecl);
}
LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
// Comma expressions just emit their LHS then their RHS as an l-value.
if (E->getOpcode() == BinaryOperator::Comma) {
EmitAnyExpr(E->getLHS());
EnsureInsertPoint();
return EmitLValue(E->getRHS());
}
if (E->getOpcode() == BinaryOperator::PtrMemD ||
E->getOpcode() == BinaryOperator::PtrMemI)
return EmitPointerToDataMemberBinaryExpr(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");
if (!hasAggregateLLVMType(E->getType())) {
// Emit the LHS as an l-value.
LValue LV = EmitLValue(E->getLHS());
// Store the value through the l-value.
EmitStoreThroughLValue(EmitAnyExpr(E->getRHS()), LV, E->getType());
return LV;
}
return EmitAggExprToLValue(E);
}
LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
RValue RV = EmitCallExpr(E);
if (!RV.isScalar())
return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
assert(E->getCallReturnType()->isReferenceType() &&
"Can't have a scalar return unless the return type is a "
"reference type!");
return MakeAddrLValue(RV.getScalarVal(), E->getType());
}
LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
// FIXME: This shouldn't require another copy.
return EmitAggExprToLValue(E);
}
LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
llvm::Value *Temp = CreateMemTemp(E->getType(), "tmp");
EmitCXXConstructExpr(Temp, E);
return MakeAddrLValue(Temp, E->getType());
}
LValue
CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType());
}
LValue
CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
LValue LV = EmitLValue(E->getSubExpr());
EmitCXXTemporary(E->getTemporary(), LV.getAddress());
return LV;
}
LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
RValue RV = EmitObjCMessageExpr(E);
if (!RV.isScalar())
return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
assert(E->getMethodDecl()->getResultType()->isReferenceType() &&
"Can't have a scalar return unless the return type is a "
"reference type!");
return MakeAddrLValue(RV.getScalarVal(), E->getType());
}
LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
llvm::Value *V =
CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true);
return MakeAddrLValue(V, E->getType());
}
llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar) {
return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
}
LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
llvm::Value *BaseValue,
const ObjCIvarDecl *Ivar,
unsigned CVRQualifiers) {
return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
Ivar, CVRQualifiers);
}
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();
Qualifiers BaseQuals;
QualType ObjectTy;
if (E->isArrow()) {
BaseValue = EmitScalarExpr(BaseExpr);
ObjectTy = BaseExpr->getType()->getPointeeType();
BaseQuals = ObjectTy.getQualifiers();
} else {
LValue BaseLV = EmitLValue(BaseExpr);
// FIXME: this isn't right for bitfields.
BaseValue = BaseLV.getAddress();
ObjectTy = BaseExpr->getType();
BaseQuals = ObjectTy.getQualifiers();
}
LValue LV =
EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
BaseQuals.getCVRQualifiers());
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
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 ObjCImplicitSetterGetterRefExpr *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::EmitObjCSuperExprLValue(const ObjCSuperExpr *E) {
return EmitUnsupportedLValue(E, "use of super");
}
LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
// Can only get l-value for message expression returning aggregate type
RValue RV = EmitAnyExprToTemp(E);
return MakeAddrLValue(RV.getAggregateAddr(), E->getType());
}
RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
ReturnValueSlot ReturnValue,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd,
const Decl *TargetDecl) {
// Get the actual function type. The callee type will always be a pointer to
// function type or a block pointer type.
assert(CalleeType->isFunctionPointerType() &&
"Call must have function pointer type!");
CalleeType = getContext().getCanonicalType(CalleeType);
const FunctionType *FnType
= cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
QualType ResultType = FnType->getResultType();
CallArgList Args;
EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
return EmitCall(CGM.getTypes().getFunctionInfo(Args, FnType),
Callee, ReturnValue, Args, TargetDecl);
}
LValue CodeGenFunction::
EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
llvm::Value *BaseV;
if (E->getOpcode() == BinaryOperator::PtrMemI)
BaseV = EmitScalarExpr(E->getLHS());
else
BaseV = EmitLValue(E->getLHS()).getAddress();
const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(getLLVMContext());
BaseV = Builder.CreateBitCast(BaseV, i8Ty);
llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
llvm::Value *AddV = Builder.CreateInBoundsGEP(BaseV, OffsetV, "add.ptr");
QualType Ty = E->getRHS()->getType();
Ty = Ty->getAs<MemberPointerType>()->getPointeeType();
const llvm::Type *PType = ConvertType(getContext().getPointerType(Ty));
AddV = Builder.CreateBitCast(AddV, PType);
return MakeAddrLValue(AddV, Ty);
}
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