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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 "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 llvm::Twine &Name) {
if (!Builder.isNamePreserving())
return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt);
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, 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 = CreateTempAlloca(ConvertType(E->getType()), "agg.tmp");
return EmitAnyExpr(E, AggLoc, IsAggLocVolatile, /*IgnoreResult=*/false,
IsInitializer);
}
RValue CodeGenFunction::EmitReferenceBindingToExpr(const Expr* E,
QualType DestType,
bool IsInitializer) {
bool ShouldDestroyTemporaries = false;
unsigned OldNumLiveTemporaries = 0;
if (const CXXExprWithTemporaries *TE = dyn_cast<CXXExprWithTemporaries>(E)) {
ShouldDestroyTemporaries = TE->shouldDestroyTemporaries();
// Keep track of the current cleanup stack depth.
if (ShouldDestroyTemporaries)
OldNumLiveTemporaries = LiveTemporaries.size();
E = TE->getSubExpr();
}
RValue Val;
if (E->isLvalue(getContext()) == Expr::LV_Valid) {
// Emit the expr as an lvalue.
LValue LV = EmitLValue(E);
if (LV.isSimple())
return RValue::get(LV.getAddress());
Val = EmitLoadOfLValue(LV, E->getType());
if (ShouldDestroyTemporaries) {
// Pop temporaries.
while (LiveTemporaries.size() > OldNumLiveTemporaries)
PopCXXTemporary();
}
} else {
const CXXRecordDecl *BaseClassDecl = 0;
const CXXRecordDecl *DerivedClassDecl = 0;
if (const CastExpr *CE =
dyn_cast<CastExpr>(E->IgnoreParenNoopCasts(getContext()))) {
if (CE->getCastKind() == CastExpr::CK_DerivedToBase) {
E = CE->getSubExpr();
BaseClassDecl =
cast<CXXRecordDecl>(CE->getType()->getAs<RecordType>()->getDecl());
DerivedClassDecl =
cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
}
}
Val = EmitAnyExprToTemp(E, /*IsAggLocVolatile=*/false,
IsInitializer);
if (ShouldDestroyTemporaries) {
// Pop temporaries.
while (LiveTemporaries.size() > OldNumLiveTemporaries)
PopCXXTemporary();
}
if (IsInitializer) {
// We might have to destroy the temporary variable.
if (const RecordType *RT = E->getType()->getAs<RecordType>()) {
if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) {
if (!ClassDecl->hasTrivialDestructor()) {
const CXXDestructorDecl *Dtor =
ClassDecl->getDestructor(getContext());
CleanupScope scope(*this);
EmitCXXDestructorCall(Dtor, Dtor_Complete, Val.getAggregateAddr());
}
}
}
}
// Check if need to perform the derived-to-base cast.
if (BaseClassDecl) {
llvm::Value *Derived = Val.getAggregateAddr();
llvm::Value *Base =
GetAddressCXXOfBaseClass(Derived, DerivedClassDecl, BaseClassDecl,
/*NullCheckValue=*/false);
return RValue::get(Base);
}
}
if (Val.isAggregate()) {
Val = RValue::get(Val.getAggregateAddr());
} else {
// Create a temporary variable that we can bind the reference to.
llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()),
"reftmp");
if (Val.isScalar())
EmitStoreOfScalar(Val.getScalarVal(), Temp, false, E->getType());
else
StoreComplexToAddr(Val.getComplexVal(), Temp, false);
Val = RValue::get(Temp);
}
return Val;
}
/// 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();
}
//===----------------------------------------------------------------------===//
// 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 LValue::MakeAddr(llvm::UndefValue::get(Ty),
MakeQualifiers(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<BinaryOperator>(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::CXXConditionDeclExprClass:
return EmitCXXConditionDeclLValue(cast<CXXConditionDeclExpr>(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::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));
case Expr::CXXZeroInitValueExprClass:
return EmitNullInitializationLValue(cast<CXXZeroInitValueExpr>(E));
}
}
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::getInt1Ty(VMContext))
V = Builder.CreateTrunc(V, llvm::Type::getInt1Ty(VMContext), "tobool");
return V;
}
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
bool Volatile, QualType Ty) {
if (Ty->isBooleanType()) {
// Bool can have different representation in memory than in registers.
const llvm::Type *SrcTy = Value->getType();
const llvm::PointerType *DstPtr = cast<llvm::PointerType>(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();
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.
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<llvm::PointerType>(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(VMContext,
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::getInt32Ty(VMContext), 1), "bf.ptr.hi");
llvm::Value *HighVal = Builder.CreateLoad(HighPtr,
LV.isVolatileQualified(),
"tmp");
// Mask off unused bits.
llvm::Constant *HighMask = llvm::ConstantInt::get(VMContext,
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->getAs<VectorType>();
if (!ExprVT) {
unsigned InIdx = getAccessedFieldNo(0, Elts);
llvm::Value *Elt = llvm::ConstantInt::get(
llvm::Type::getInt32Ty(VMContext), 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(
llvm::Type::getInt32Ty(VMContext), 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);
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(), Ty);
}
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<llvm::PointerType>(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(VMContext,
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(VMContext,
~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::getInt32Ty(VMContext), 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(VMContext, ~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->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(
llvm::Type::getInt32Ty(VMContext), 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;
const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
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);
const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
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(LV, true);
ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
LV.setBaseIvarExp(Exp->getBase());
LV.SetObjCArray(LV, 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(LV, true);
}
LV.SetObjCArray(LV, 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(LV, 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(LV, 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(LV, 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(LV, 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");
LValue LV = LValue::MakeAddr(V, CGF.MakeQualifiers(E->getType()));
setObjCGCLValueClass(CGF.getContext(), E, LV);
return LV;
}
LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
const NamedDecl *ND = E->getDecl();
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];
assert(V && "DeclRefExpr not entered in LocalDeclMap?");
Qualifiers Quals = MakeQualifiers(E->getType());
// local variables do not get their gc attribute set.
// local static?
if (NonGCable) Quals.removeObjCGCAttr();
if (VD->hasAttr<BlocksAttr>()) {
V = Builder.CreateStructGEP(V, 1, "forwarding");
V = Builder.CreateLoad(V, false);
V = Builder.CreateStructGEP(V, getByRefValueLLVMField(VD),
VD->getNameAsString());
}
if (VD->getType()->isReferenceType())
V = Builder.CreateLoad(V, "tmp");
LValue LV = LValue::MakeAddr(V, Quals);
LValue::SetObjCNonGC(LV, NonGCable);
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
llvm::Value* V = 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 =
getContext().getFunctionNoProtoType(Proto->getResultType());
NoProtoType = getContext().getPointerType(NoProtoType);
V = Builder.CreateBitCast(V, ConvertType(NoProtoType), "tmp");
}
}
return LValue::MakeAddr(V, MakeQualifiers(E->getType()));
}
if (E->getQualifier()) {
// FIXME: the qualifier check does not seem sufficient here
return EmitPointerToDataMemberLValue(cast<FieldDecl>(ND));
}
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) {
return LValue::MakeAddr(GetAddrOfBlockDecl(E), MakeQualifiers(E->getType()));
}
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");
Qualifiers Quals = MakeQualifiers(T);
Quals.setAddressSpace(ExprTy.getAddressSpace());
LValue LV = LValue::MakeAddr(EmitScalarExpr(E->getSubExpr()), Quals);
// 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())
LValue::SetObjCNonGC(LV, !E->isOBJCGCCandidate(getContext()));
return LV;
}
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"),
MakeQualifiers(ExprTy));
}
case UnaryOperator::PreInc:
case UnaryOperator::PreDec:
return EmitUnsupportedLValue(E, "pre-inc/dec expression");
}
}
LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromLiteral(E),
Qualifiers());
}
LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
return LValue::MakeAddr(CGM.GetAddrOfConstantStringFromObjCEncode(E),
Qualifiers());
}
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:
GlobalVarName = "__PRETTY_FUNCTION__.";
break;
}
llvm::StringRef FnName = CurFn->getName();
if (FnName.startswith("\01"))
FnName = FnName.substr(1);
GlobalVarName += FnName;
std::string FunctionName =
PredefinedExpr::ComputeName(getContext(), (PredefinedExpr::IdentType)Type,
CurCodeDecl);
llvm::Constant *C =
CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str());
return LValue::MakeAddr(C, Qualifiers());
}
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());
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,
llvm::Type::getInt32Ty(VMContext), IdxSigned, "vidx");
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.
unsigned IdxBitwidth = cast<llvm::IntegerType>(Idx->getType())->getBitWidth();
if (IdxBitwidth != LLVMPointerWidth)
Idx = Builder.CreateIntCast(Idx,
llvm::IntegerType::get(VMContext, LLVMPointerWidth),
IdxSigned, "idxprom");
// 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);
uint64_t BaseTypeSize = getContext().getTypeSize(BaseType) / 8;
Idx = Builder.CreateUDiv(Idx,
llvm::ConstantInt::get(Idx->getType(),
BaseTypeSize));
Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
} else if (const ObjCInterfaceType *OIT =
dyn_cast<ObjCInterfaceType>(E->getType())) {
llvm::Value *InterfaceSize =
llvm::ConstantInt::get(Idx->getType(),
getContext().getTypeSize(OIT) / 8);
Idx = Builder.CreateMul(Idx, InterfaceSize);
const llvm::Type *i8PTy = llvm::Type::getInt8PtrTy(VMContext);
Address = Builder.CreateGEP(Builder.CreateBitCast(Base, i8PTy),
Idx, "arrayidx");
Address = Builder.CreateBitCast(Address, Base->getType());
} else {
Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
}
QualType T = E->getBase()->getType()->getPointeeType();
assert(!T.isNull() &&
"CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
Qualifiers Quals = MakeQualifiers(T);
Quals.setAddressSpace(E->getBase()->getType().getAddressSpace());
LValue LV = LValue::MakeAddr(Address, Quals);
if (getContext().getLangOptions().ObjC1 &&
getContext().getLangOptions().getGCMode() != LangOptions::NonGC) {
LValue::SetObjCNonGC(LV, !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;
for (unsigned i = 0, e = Elts.size(); i != e; ++i)
CElts.push_back(llvm::ConstantInt::get(
llvm::Type::getInt32Ty(VMContext), 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()->getAs<PointerType>();
llvm::Value *Ptr = EmitScalarExpr(E->getBase());
Qualifiers Quals = MakeQualifiers(PT->getPointeeType());
Quals.removeObjCGCAttr();
Base = LValue::MakeAddr(Ptr, Quals);
}
// 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;
const llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext);
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 isUnion = false;
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>();
if (PTy->getPointeeType()->isUnionType())
isUnion = true;
BaseQuals = PTy->getPointeeType().getQualifiers();
} else if (isa<ObjCPropertyRefExpr>(BaseExpr->IgnoreParens()) ||
isa<ObjCImplicitSetterGetterRefExpr>(
BaseExpr->IgnoreParens())) {
RValue RV = EmitObjCPropertyGet(BaseExpr);
BaseValue = RV.getAggregateAddr();
if (BaseExpr->getType()->isUnionType())
isUnion = true;
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();
if (BaseTy->isUnionType())
isUnion = true;
BaseQuals = BaseTy.getQualifiers();
}
NamedDecl *ND = E->getMemberDecl();
if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) {
LValue LV = EmitLValueForField(BaseValue, Field, isUnion,
BaseQuals.getCVRQualifiers());
LValue::SetObjCNonGC(LV, isNonGC);
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
if (VarDecl *VD = dyn_cast<VarDecl>(ND))
return EmitGlobalVarDeclLValue(*this, E, VD);
assert(false && "Unhandled member declaration!");
return LValue();
}
LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value* BaseValue,
FieldDecl* Field,
unsigned CVRQualifiers) {
CodeGenTypes::BitFieldInfo Info = CGM.getTypes().getBitFieldInfo(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<llvm::PointerType>(BaseValue->getType());
unsigned AS = BaseTy->getAddressSpace();
BaseValue = Builder.CreateBitCast(BaseValue,
llvm::PointerType::get(FieldTy, AS),
"tmp");
llvm::Value *Idx =
llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), Info.FieldNo);
llvm::Value *V = Builder.CreateGEP(BaseValue, Idx, "tmp");
return LValue::MakeBitfield(V, Info.Start, Info.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<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");
Qualifiers Quals = MakeQualifiers(Field->getType());
Quals.addCVRQualifiers(CVRQualifiers);
// __weak attribute on a field is ignored.
if (Quals.getObjCGCAttr() == Qualifiers::Weak)
Quals.removeObjCGCAttr();
return LValue::MakeAddr(V, Quals);
}
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, MakeQualifiers(E->getType()));
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;
}
LValue
CodeGenFunction::EmitConditionalOperatorLValue(const ConditionalOperator* E) {
if (E->isLvalue(getContext()) == Expr::LV_Valid) {
llvm::BasicBlock *LHSBlock = createBasicBlock("cond.true");
llvm::BasicBlock *RHSBlock = createBasicBlock("cond.false");
llvm::BasicBlock *ContBlock = createBasicBlock("cond.end");
llvm::Value *Cond = EvaluateExprAsBool(E->getCond());
Builder.CreateCondBr(Cond, LHSBlock, RHSBlock);
EmitBlock(LHSBlock);
LValue LHS = EmitLValue(E->getLHS());
if (!LHS.isSimple())
return EmitUnsupportedLValue(E, "conditional operator");
llvm::Value *Temp = CreateTempAlloca(LHS.getAddress()->getType(),"condtmp");
Builder.CreateStore(LHS.getAddress(), Temp);
EmitBranch(ContBlock);
EmitBlock(RHSBlock);
LValue RHS = EmitLValue(E->getRHS());
if (!RHS.isSimple())
return EmitUnsupportedLValue(E, "conditional operator");
Builder.CreateStore(RHS.getAddress(), Temp);
EmitBranch(ContBlock);
EmitBlock(ContBlock);
Temp = Builder.CreateLoad(Temp, "lv");
return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
}
// ?: here should be an aggregate.
assert((hasAggregateLLVMType(E->getType()) &&
!E->getType()->isAnyComplexType()) &&
"Unexpected conditional operator!");
llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
EmitAggExpr(E, Temp, false);
return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
}
/// EmitCastLValue - Casts are never lvalues. 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()) {
default:
// If this is an lvalue cast, treat it as a no-op.
// FIXME: We shouldn't need to check for this explicitly!
if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E))
if (ICE->isLvalueCast())
return EmitLValue(E->getSubExpr());
assert(0 && "Unhandled cast!");
case CastExpr::CK_NoOp:
case CastExpr::CK_ConstructorConversion:
case CastExpr::CK_UserDefinedConversion:
return EmitLValue(E->getSubExpr());
case CastExpr::CK_DerivedToBase: {
const RecordType *DerivedClassTy =
E->getSubExpr()->getType()->getAs<RecordType>();
CXXRecordDecl *DerivedClassDecl =
cast<CXXRecordDecl>(DerivedClassTy->getDecl());
const RecordType *BaseClassTy = E->getType()->getAs<RecordType>();
CXXRecordDecl *BaseClassDecl = cast<CXXRecordDecl>(BaseClassTy->getDecl());
LValue LV = EmitLValue(E->getSubExpr());
// Perform the derived-to-base conversion
llvm::Value *Base =
GetAddressCXXOfBaseClass(LV.getAddress(), DerivedClassDecl,
BaseClassDecl, /*NullCheckValue=*/false);
return LValue::MakeAddr(Base, MakeQualifiers(E->getType()));
}
case CastExpr::CK_ToUnion: {
llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
EmitAnyExpr(E->getSubExpr(), Temp, false);
return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
}
}
}
LValue CodeGenFunction::EmitNullInitializationLValue(
const CXXZeroInitValueExpr *E) {
QualType Ty = E->getType();
const llvm::Type *LTy = ConvertTypeForMem(Ty);
llvm::AllocaInst *Alloc = CreateTempAlloca(LTy);
unsigned Align = getContext().getTypeAlign(Ty)/8;
Alloc->setAlignment(Align);
LValue lvalue = LValue::MakeAddr(Alloc, Qualifiers());
EmitMemSetToZero(lvalue.getAddress(), Ty);
return lvalue;
}
//===--------------------------------------------------------------------===//
// Expression Emission
//===--------------------------------------------------------------------===//
RValue CodeGenFunction::EmitCallExpr(const CallExpr *E) {
// Builtins never have block type.
if (E->getCallee()->getType()->isBlockPointerType())
return EmitBlockCallExpr(E);
if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E))
return EmitCXXMemberCallExpr(CE);
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);
if (isa<CXXPseudoDestructorExpr>(E->getCallee())) {
// 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(Callee, E->getCallee()->getType(),
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());
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());
llvm::Value *RHS = EmitScalarExpr(E->getRHS());
EmitStoreOfScalar(RHS, LV.getAddress(), LV.isVolatileQualified(),
E->getType());
return LV;
}
llvm::Value *Temp = CreateTempAlloca(ConvertType(E->getType()));
EmitAggExpr(E, Temp, false);
// FIXME: Are these qualifiers correct?
return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
}
LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
RValue RV = EmitCallExpr(E);
if (!RV.isScalar())
return LValue::MakeAddr(RV.getAggregateAddr(),MakeQualifiers(E->getType()));
assert(E->getCallReturnType()->isReferenceType() &&
"Can't have a scalar return unless the return type is a "
"reference type!");
return LValue::MakeAddr(RV.getScalarVal(), MakeQualifiers(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, MakeQualifiers(E->getType()));
}
LValue
CodeGenFunction::EmitCXXConditionDeclLValue(const CXXConditionDeclExpr *E) {
EmitLocalBlockVarDecl(*E->getVarDecl());
return EmitDeclRefLValue(E);
}
LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
llvm::Value *Temp = CreateTempAlloca(ConvertTypeForMem(E->getType()), "tmp");
EmitCXXConstructExpr(Temp, E);
return LValue::MakeAddr(Temp, MakeQualifiers(E->getType()));
}
LValue
CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
LValue LV = EmitLValue(E->getSubExpr());
PushCXXTemporary(E->getTemporary(), LV.getAddress());
return LV;
}
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(), MakeQualifiers(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);
// FIXME: can this be volatile?
return LValue::MakeAddr(RV.getAggregateAddr(), MakeQualifiers(E->getType()));
}
LValue CodeGenFunction::EmitPointerToDataMemberLValue(const FieldDecl *Field) {
const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(Field->getDeclContext());
QualType NNSpecTy =
getContext().getCanonicalType(
getContext().getTypeDeclType(const_cast<CXXRecordDecl*>(ClassDecl)));
NNSpecTy = getContext().getPointerType(NNSpecTy);
llvm::Value *V = llvm::Constant::getNullValue(ConvertType(NNSpecTy));
LValue MemExpLV = EmitLValueForField(V, const_cast<FieldDecl*>(Field),
/*isUnion*/false, /*Qualifiers*/0);
const llvm::Type *ResultType = ConvertType(getContext().getPointerDiffType());
V = Builder.CreatePtrToInt(MemExpLV.getAddress(), ResultType, "datamember");
return LValue::MakeAddr(V, MakeQualifiers(Field->getType()));
}
RValue CodeGenFunction::EmitCall(llvm::Value *Callee, QualType CalleeType,
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);
QualType FnType = cast<PointerType>(CalleeType)->getPointeeType();
QualType ResultType = cast<FunctionType>(FnType)->getResultType();
CallArgList Args;
EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd);
// FIXME: We should not need to do this, it should be part of the function
// type.
unsigned CallingConvention = 0;
if (const llvm::Function *F =
dyn_cast<llvm::Function>(Callee->stripPointerCasts()))
CallingConvention = F->getCallingConv();
return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args,
CallingConvention),
Callee, Args, TargetDecl);
}
LValue CodeGenFunction::
EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
llvm::Value *BaseV = EmitLValue(E->getLHS()).getAddress();
if (E->getOpcode() == BinaryOperator::PtrMemI)
BaseV = Builder.CreateLoad(BaseV, "indir.ptr");
const llvm::Type *i8Ty = llvm::Type::getInt8PtrTy(getLLVMContext());
BaseV = Builder.CreateBitCast(BaseV, i8Ty);
LValue RHSLV = EmitLValue(E->getRHS());
llvm::Value *OffsetV =
EmitLoadOfLValue(RHSLV, E->getRHS()->getType()).getScalarVal();
const llvm::Type* ResultType = ConvertType(getContext().getPointerDiffType());
OffsetV = Builder.CreateBitCast(OffsetV, ResultType);
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 LValue::MakeAddr(AddV, MakeQualifiers(Ty));
}
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