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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 "CGCXXABI.h"
#include "CGDebugInfo.h"
#include "CGRecordLayout.h"
#include "CGObjCRuntime.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "llvm/Intrinsics.h"
#include "llvm/LLVMContext.h"
#include "llvm/Target/TargetData.h"
using namespace clang;
using namespace CodeGen;
//===--------------------------------------------------------------------===//
// Miscellaneous Helper Methods
//===--------------------------------------------------------------------===//
llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
unsigned addressSpace =
cast<llvm::PointerType>(value->getType())->getAddressSpace();
llvm::PointerType *destType = Int8PtrTy;
if (addressSpace)
destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
if (value->getType() == destType) return value;
return Builder.CreateBitCast(value, destType);
}
/// CreateTempAlloca - This creates a alloca and inserts it into the entry
/// block.
llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
const 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 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 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) {
if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
llvm::Value *MemPtr = EmitScalarExpr(E);
return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
}
QualType BoolTy = getContext().BoolTy;
if (!E->getType()->isAnyComplexType())
return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy);
return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy);
}
/// EmitIgnoredExpr - Emit code to compute the specified expression,
/// ignoring the result.
void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
if (E->isRValue())
return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
// Just emit it as an l-value and drop the result.
EmitLValue(E);
}
/// 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, AggSlot indicates where the
/// result should be returned.
RValue CodeGenFunction::EmitAnyExpr(const Expr *E, AggValueSlot AggSlot,
bool IgnoreResult) {
if (!hasAggregateLLVMType(E->getType()))
return RValue::get(EmitScalarExpr(E, IgnoreResult));
else if (E->getType()->isAnyComplexType())
return RValue::getComplex(EmitComplexExpr(E, IgnoreResult, IgnoreResult));
EmitAggExpr(E, AggSlot, IgnoreResult);
return AggSlot.asRValue();
}
/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
/// always be accessible even if no aggregate location is provided.
RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
AggValueSlot AggSlot = AggValueSlot::ignored();
if (hasAggregateLLVMType(E->getType()) &&
!E->getType()->isAnyComplexType())
AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
return EmitAnyExpr(E, AggSlot);
}
/// EmitAnyExprToMem - Evaluate an expression into a given memory
/// location.
void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
llvm::Value *Location,
Qualifiers Quals,
bool IsInit) {
// FIXME: This function should take an LValue as an argument.
if (E->getType()->isAnyComplexType()) {
EmitComplexExprIntoAddr(E, Location, Quals.hasVolatile());
} else if (hasAggregateLLVMType(E->getType())) {
CharUnits Alignment = getContext().getTypeAlignInChars(E->getType());
EmitAggExpr(E, AggValueSlot::forAddr(Location, Alignment, Quals,
AggValueSlot::IsDestructed_t(IsInit),
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsAliased_t(!IsInit)));
} else {
RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
LValue LV = MakeAddrLValue(Location, E->getType());
EmitStoreThroughLValue(RV, LV);
}
}
namespace {
/// \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;
llvm::raw_svector_ostream Out(Name);
CGF.CGM.getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out);
Out.flush();
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,
QualType &ObjCARCReferenceLifetimeType,
const NamedDecl *InitializedDecl) {
// Look through single-element init lists that claim to be lvalues. They're
// just syntactic wrappers in this case.
if (const InitListExpr *ILE = dyn_cast<InitListExpr>(E)) {
if (ILE->getNumInits() == 1 && ILE->isGLValue())
E = ILE->getInit(0);
}
// Look through expressions for materialized temporaries (for now).
if (const MaterializeTemporaryExpr *M
= dyn_cast<MaterializeTemporaryExpr>(E)) {
// Objective-C++ ARC:
// If we are binding a reference to a temporary that has ownership, we
// need to perform retain/release operations on the temporary.
if (CGF.getContext().getLangOptions().ObjCAutoRefCount &&
E->getType()->isObjCLifetimeType() &&
(E->getType().getObjCLifetime() == Qualifiers::OCL_Strong ||
E->getType().getObjCLifetime() == Qualifiers::OCL_Weak ||
E->getType().getObjCLifetime() == Qualifiers::OCL_Autoreleasing))
ObjCARCReferenceLifetimeType = E->getType();
E = M->GetTemporaryExpr();
}
if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E))
E = DAE->getExpr();
if (const ExprWithCleanups *EWC = dyn_cast<ExprWithCleanups>(E)) {
CGF.enterFullExpression(EWC);
CodeGenFunction::RunCleanupsScope Scope(CGF);
return EmitExprForReferenceBinding(CGF, EWC->getSubExpr(),
ReferenceTemporary,
ReferenceTemporaryDtor,
ObjCARCReferenceLifetimeType,
InitializedDecl);
}
RValue RV;
if (E->isGLValue()) {
// 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);
} else {
if (!ObjCARCReferenceLifetimeType.isNull()) {
ReferenceTemporary = CreateReferenceTemporary(CGF,
ObjCARCReferenceLifetimeType,
InitializedDecl);
LValue RefTempDst = CGF.MakeAddrLValue(ReferenceTemporary,
ObjCARCReferenceLifetimeType);
CGF.EmitScalarInit(E, dyn_cast_or_null<ValueDecl>(InitializedDecl),
RefTempDst, false);
bool ExtendsLifeOfTemporary = false;
if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(InitializedDecl)) {
if (Var->extendsLifetimeOfTemporary())
ExtendsLifeOfTemporary = true;
} else if (InitializedDecl && isa<FieldDecl>(InitializedDecl)) {
ExtendsLifeOfTemporary = true;
}
if (!ExtendsLifeOfTemporary) {
// Since the lifetime of this temporary isn't going to be extended,
// we need to clean it up ourselves at the end of the full expression.
switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) {
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
case Qualifiers::OCL_Autoreleasing:
break;
case Qualifiers::OCL_Strong: {
assert(!ObjCARCReferenceLifetimeType->isArrayType());
CleanupKind cleanupKind = CGF.getARCCleanupKind();
CGF.pushDestroy(cleanupKind,
ReferenceTemporary,
ObjCARCReferenceLifetimeType,
CodeGenFunction::destroyARCStrongImprecise,
cleanupKind & EHCleanup);
break;
}
case Qualifiers::OCL_Weak:
assert(!ObjCARCReferenceLifetimeType->isArrayType());
CGF.pushDestroy(NormalAndEHCleanup,
ReferenceTemporary,
ObjCARCReferenceLifetimeType,
CodeGenFunction::destroyARCWeak,
/*useEHCleanupForArray*/ true);
break;
}
ObjCARCReferenceLifetimeType = QualType();
}
return ReferenceTemporary;
}
SmallVector<SubobjectAdjustment, 2> Adjustments;
while (true) {
E = E->IgnoreParens();
if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
if ((CE->getCastKind() == CK_DerivedToBase ||
CE->getCastKind() == 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() == CK_NoOp) {
E = CE->getSubExpr();
continue;
}
} else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
if (!ME->isArrow() && ME->getBase()->isRValue()) {
assert(ME->getBase()->getType()->isRecordType());
if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
E = ME->getBase();
Adjustments.push_back(SubobjectAdjustment(Field));
continue;
}
}
}
if (const OpaqueValueExpr *opaque = dyn_cast<OpaqueValueExpr>(E))
if (opaque->getType()->isRecordType())
return CGF.EmitOpaqueValueLValue(opaque).getAddress();
// Nothing changed.
break;
}
// Create a reference temporary if necessary.
AggValueSlot AggSlot = AggValueSlot::ignored();
if (CGF.hasAggregateLLVMType(E->getType()) &&
!E->getType()->isAnyComplexType()) {
ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(),
InitializedDecl);
CharUnits Alignment = CGF.getContext().getTypeAlignInChars(E->getType());
AggValueSlot::IsDestructed_t isDestructed
= AggValueSlot::IsDestructed_t(InitializedDecl != 0);
AggSlot = AggValueSlot::forAddr(ReferenceTemporary, Alignment,
Qualifiers(), isDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased);
}
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();
}
}
RV = CGF.EmitAnyExpr(E, AggSlot);
// 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), TempLV);
break;
}
}
}
return Object;
}
}
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;
QualType ObjCARCReferenceLifetimeType;
llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary,
ReferenceTemporaryDtor,
ObjCARCReferenceLifetimeType,
InitializedDecl);
if (!ReferenceTemporaryDtor && ObjCARCReferenceLifetimeType.isNull())
return RValue::get(Value);
// Make sure to call the destructor for the reference temporary.
const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl);
if (VD && VD->hasGlobalStorage()) {
if (ReferenceTemporaryDtor) {
llvm::Constant *DtorFn =
CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete);
EmitCXXGlobalDtorRegistration(DtorFn,
cast<llvm::Constant>(ReferenceTemporary));
} else {
assert(!ObjCARCReferenceLifetimeType.isNull());
// Note: We intentionally do not register a global "destructor" to
// release the object.
}
return RValue::get(Value);
}
if (ReferenceTemporaryDtor)
PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary);
else {
switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) {
case Qualifiers::OCL_None:
llvm_unreachable(
"Not a reference temporary that needs to be deallocated");
case Qualifiers::OCL_ExplicitNone:
case Qualifiers::OCL_Autoreleasing:
// Nothing to do.
break;
case Qualifiers::OCL_Strong: {
bool precise = VD && VD->hasAttr<ObjCPreciseLifetimeAttr>();
CleanupKind cleanupKind = getARCCleanupKind();
// This local is a GCC and MSVC compiler workaround.
Destroyer *destroyer = precise ? &destroyARCStrongPrecise :
&destroyARCStrongImprecise;
pushDestroy(cleanupKind, ReferenceTemporary, ObjCARCReferenceLifetimeType,
*destroyer, cleanupKind & EHCleanup);
break;
}
case Qualifiers::OCL_Weak: {
// This local is a GCC and MSVC compiler workaround.
Destroyer *destroyer = &destroyARCWeak;
// __weak objects always get EH cleanups; otherwise, exceptions
// could cause really nasty crashes instead of mere leaks.
pushDestroy(NormalAndEHCleanup, ReferenceTemporary,
ObjCARCReferenceLifetimeType, *destroyer, true);
break;
}
}
}
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;
// This needs to be to the standard address space.
Address = Builder.CreateBitCast(Address, Int8PtrTy);
llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, IntPtrTy);
// In time, people may want to control this and use a 1 here.
llvm::Value *Arg = Builder.getFalse();
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>()) {
llvm::Type *EltTy = ConvertType(CTy->getElementType());
llvm::Value *U = llvm::UndefValue::get(EltTy);
return RValue::getComplex(std::make_pair(U, U));
}
// If this is a use of an undefined aggregate type, the aggregate must have an
// identifiable address. Just because the contents of the value are undefined
// doesn't mean that the address can't be taken and compared.
if (hasAggregateLLVMType(Ty)) {
llvm::Value *DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
return RValue::getAggregate(DestPtr);
}
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().getTypeSizeInChars(E->getType()).getQuantity());
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::ObjCPropertyRefExprClass:
llvm_unreachable("cannot emit a property reference directly");
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:
if (!E->getType()->isAnyComplexType())
return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
return EmitComplexCompoundAssignmentLValue(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::GenericSelectionExprClass:
return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
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::PseudoObjectExprClass:
return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
case Expr::InitListExprClass:
assert(cast<InitListExpr>(E)->getNumInits() == 1 &&
"Only single-element init list can be lvalue.");
return EmitLValue(cast<InitListExpr>(E)->getInit(0));
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::ExprWithCleanupsClass: {
const ExprWithCleanups *cleanups = cast<ExprWithCleanups>(E);
enterFullExpression(cleanups);
RunCleanupsScope Scope(*this);
return EmitLValue(cleanups->getSubExpr());
}
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::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::BinaryConditionalOperatorClass:
return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
case Expr::ChooseExprClass:
return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext()));
case Expr::OpaqueValueExprClass:
return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
case Expr::SubstNonTypeTemplateParmExprClass:
return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
case Expr::ImplicitCastExprClass:
case Expr::CStyleCastExprClass:
case Expr::CXXFunctionalCastExprClass:
case Expr::CXXStaticCastExprClass:
case Expr::CXXDynamicCastExprClass:
case Expr::CXXReinterpretCastExprClass:
case Expr::CXXConstCastExprClass:
case Expr::ObjCBridgedCastExprClass:
return EmitCastLValue(cast<CastExpr>(E));
case Expr::MaterializeTemporaryExprClass:
return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
}
}
llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue) {
return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
lvalue.getAlignment().getQuantity(),
lvalue.getType(), lvalue.getTBAAInfo());
}
llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
unsigned Alignment, QualType Ty,
llvm::MDNode *TBAAInfo) {
llvm::LoadInst *Load = Builder.CreateLoad(Addr);
if (Volatile)
Load->setVolatile(true);
if (Alignment)
Load->setAlignment(Alignment);
if (TBAAInfo)
CGM.DecorateInstruction(Load, TBAAInfo);
// If this is an atomic type, all normal reads must be atomic
if (Ty->isAtomicType())
Load->setAtomic(llvm::SequentiallyConsistent);
return EmitFromMemory(Load, Ty);
}
static bool isBooleanUnderlyingType(QualType Ty) {
if (const EnumType *ET = dyn_cast<EnumType>(Ty))
return ET->getDecl()->getIntegerType()->isBooleanType();
return false;
}
llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
// Bool has a different representation in memory than in registers.
if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
// This should really always be an i1, but sometimes it's already
// an i8, and it's awkward to track those cases down.
if (Value->getType()->isIntegerTy(1))
return Builder.CreateZExt(Value, Builder.getInt8Ty(), "frombool");
assert(Value->getType()->isIntegerTy(8) && "value rep of bool not i1/i8");
}
return Value;
}
llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
// Bool has a different representation in memory than in registers.
if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) {
assert(Value->getType()->isIntegerTy(8) && "memory rep of bool not i8");
return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
}
return Value;
}
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
bool Volatile, unsigned Alignment,
QualType Ty,
llvm::MDNode *TBAAInfo,
bool isInit) {
Value = EmitToMemory(Value, Ty);
llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
if (Alignment)
Store->setAlignment(Alignment);
if (TBAAInfo)
CGM.DecorateInstruction(Store, TBAAInfo);
if (!isInit && Ty->isAtomicType())
Store->setAtomic(llvm::SequentiallyConsistent);
}
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
bool isInit) {
EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
lvalue.getAlignment().getQuantity(), lvalue.getType(),
lvalue.getTBAAInfo(), isInit);
}
/// 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) {
if (LV.isObjCWeak()) {
// load of a __weak object.
llvm::Value *AddrWeakObj = LV.getAddress();
return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
AddrWeakObj));
}
if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak)
return RValue::get(EmitARCLoadWeak(LV.getAddress()));
if (LV.isSimple()) {
assert(!LV.getType()->isFunctionType());
// Everything needs a load.
return RValue::get(EmitLoadOfScalar(LV));
}
if (LV.isVectorElt()) {
llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(),
LV.isVolatileQualified());
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);
assert(LV.isBitField() && "Unknown LValue type!");
return EmitLoadOfBitfieldLValue(LV);
}
RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV) {
const CGBitFieldInfo &Info = LV.getBitFieldInfo();
// Get the output type.
llvm::Type *ResLTy = ConvertType(LV.getType());
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.isZero()) {
Ptr = EmitCastToVoidPtr(Ptr);
Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(),
"bf.field.offs");
}
// Cast to the access type.
llvm::Type *PTy = llvm::Type::getIntNPtrTy(getLLVMContext(),
AI.AccessWidth,
CGM.getContext().getTargetAddressSpace(LV.getType()));
Ptr = Builder.CreateBitCast(Ptr, PTy);
// Perform the load.
llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified());
if (!AI.AccessAlignment.isZero())
Load->setAlignment(AI.AccessAlignment.getQuantity());
// 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);
}
// If this is a reference to a subset of the elements of a vector, create an
// appropriate shufflevector.
RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(),
LV.isVolatileQualified());
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 = LV.getType()->getAs<VectorType>();
if (!ExprVT) {
unsigned InIdx = getAccessedFieldNo(0, Elts);
llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx);
return RValue::get(Builder.CreateExtractElement(Vec, Elt));
}
// Always use shuffle vector to try to retain the original program structure
unsigned NumResultElts = ExprVT->getNumElements();
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);
Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
MaskV);
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, bool isInit) {
if (!Dst.isSimple()) {
if (Dst.isVectorElt()) {
// Read/modify/write the vector, inserting the new element.
llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(),
Dst.isVolatileQualified());
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);
assert(Dst.isBitField() && "Unknown LValue type");
return EmitStoreThroughBitfieldLValue(Src, Dst);
}
// There's special magic for assigning into an ARC-qualified l-value.
if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
switch (Lifetime) {
case Qualifiers::OCL_None:
llvm_unreachable("present but none");
case Qualifiers::OCL_ExplicitNone:
// nothing special
break;
case Qualifiers::OCL_Strong:
EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
return;
case Qualifiers::OCL_Weak:
EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
return;
case Qualifiers::OCL_Autoreleasing:
Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
Src.getScalarVal()));
// fall into the normal path
break;
}
}
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");
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, isInit);
}
void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
llvm::Value **Result) {
const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
// Get the output type.
llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy);
// Get the source value, truncated to the width of the bit-field.
llvm::Value *SrcVal = Src.getScalarVal();
if (Dst.getType()->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.
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();
unsigned addressSpace =
cast<llvm::PointerType>(Ptr->getType())->getAddressSpace();
// 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.isZero()) {
Ptr = EmitCastToVoidPtr(Ptr);
Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(),
"bf.field.offs");
}
// Cast to the access type.
llvm::Type *AccessLTy =
llvm::Type::getIntNTy(getLLVMContext(), AI.AccessWidth);
llvm::Type *PTy = AccessLTy->getPointerTo(addressSpace);
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.
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.isZero())
Load->setAlignment(AI.AccessAlignment.getQuantity());
// 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.isZero())
Store->setAlignment(AI.AccessAlignment.getQuantity());
}
}
void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
LValue Dst) {
// 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());
const llvm::Constant *Elts = Dst.getExtVectorElts();
llvm::Value *SrcVal = Src.getScalarVal();
if (const VectorType *VTy = Dst.getType()->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.
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);
Vec = Builder.CreateShuffleVector(SrcVal,
llvm::UndefValue::get(Vec->getType()),
MaskV);
} 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.
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);
llvm::Value *ExtSrcVal =
Builder.CreateShuffleVector(SrcVal,
llvm::UndefValue::get(SrcVal->getType()),
ExtMaskV);
// build identity
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);
Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
} else {
// We should never shorten the vector
llvm_unreachable("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);
}
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,
bool IsMemberAccess=false) {
if (Ctx.getLangOptions().getGC() == LangOptions::NonGC)
return;
if (isa<ObjCIvarRefExpr>(E)) {
QualType ExpTy = E->getType();
if (IsMemberAccess && ExpTy->isPointerType()) {
// If ivar is a structure pointer, assigning to field of
// this struct follows gcc's behavior and makes it a non-ivar
// writer-barrier conservatively.
ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
if (ExpTy->isRecordType()) {
LV.setObjCIvar(false);
return;
}
}
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->hasGlobalStorage()) {
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, IsMemberAccess);
return;
}
if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
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 GenericSelectionExpr *Exp = dyn_cast<GenericSelectionExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
return;
}
if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const ObjCBridgedCastExpr *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
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, true);
// 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 llvm::Value *
EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
llvm::Value *V, llvm::Type *IRType,
StringRef Name = StringRef()) {
unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
}
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);
llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
QualType T = E->getType();
LValue LV;
if (VD->getType()->isReferenceType()) {
llvm::LoadInst *LI = CGF.Builder.CreateLoad(V);
LI->setAlignment(Alignment.getQuantity());
V = LI;
LV = CGF.MakeNaturalAlignAddrLValue(V, T);
} else {
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));
}
}
CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
return CGF.MakeAddrLValue(V, E->getType(), Alignment);
}
LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
const NamedDecl *ND = E->getDecl();
CharUnits Alignment = getContext().getDeclAlign(ND);
QualType T = E->getType();
// FIXME: We should be able to assert this for FunctionDecls as well!
// FIXME: We should be able to assert this for all DeclRefExprs, not just
// those with a valid source location.
assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
!E->getLocation().isValid()) &&
"Should not use decl without marking it used!");
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->getType()->isReferenceType() &&
!VD->hasAttr<BlocksAttr>();
llvm::Value *V = LocalDeclMap[VD];
if (!V && VD->isStaticLocal())
V = CGM.getStaticLocalDeclAddress(VD);
assert(V && "DeclRefExpr not entered in LocalDeclMap?");
if (VD->hasAttr<BlocksAttr>())
V = BuildBlockByrefAddress(V, VD);
LValue LV;
if (VD->getType()->isReferenceType()) {
llvm::LoadInst *LI = Builder.CreateLoad(V);
LI->setAlignment(Alignment.getQuantity());
V = LI;
LV = MakeNaturalAlignAddrLValue(V, T);
} else {
LV = MakeAddrLValue(V, T, Alignment);
}
if (NonGCable) {
LV.getQuals().removeObjCGCAttr();
LV.setNonGC(true);
}
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
if (const FunctionDecl *fn = dyn_cast<FunctionDecl>(ND))
return EmitFunctionDeclLValue(*this, E, fn);
llvm_unreachable("Unhandled DeclRefExpr");
}
LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) {
CharUnits Alignment = getContext().getDeclAlign(E->getDecl());
return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment);
}
LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
// __extension__ doesn't affect lvalue-ness.
if (E->getOpcode() == UO_Extension)
return EmitLValue(E->getSubExpr());
QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
switch (E->getOpcode()) {
default: llvm_unreachable("Unknown unary operator lvalue!");
case UO_Deref: {
QualType T = E->getSubExpr()->getType()->getPointeeType();
assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
LValue LV = MakeNaturalAlignAddrLValue(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().getGC() != LangOptions::NonGC &&
LV.isObjCWeak())
LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
return LV;
}
case UO_Real:
case UO_Imag: {
LValue LV = EmitLValue(E->getSubExpr());
assert(LV.isSimple() && "real/imag on non-ordinary l-value");
llvm::Value *Addr = LV.getAddress();
// real and imag are valid on scalars. This is a faster way of
// testing that.
if (!cast<llvm::PointerType>(Addr->getType())
->getElementType()->isStructTy()) {
assert(E->getSubExpr()->getType()->isArithmeticType());
return LV;
}
assert(E->getSubExpr()->getType()->isAnyComplexType());
unsigned Idx = E->getOpcode() == UO_Imag;
return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(),
Idx, "idx"),
ExprTy);
}
case UO_PreInc:
case UO_PreDec: {
LValue LV = EmitLValue(E->getSubExpr());
bool isInc = E->getOpcode() == UO_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: llvm_unreachable("Invalid type");
case PredefinedExpr::Func:
GlobalVarName = "__func__.";
break;
case PredefinedExpr::Function:
GlobalVarName = "__FUNCTION__.";
break;
case PredefinedExpr::PrettyFunction:
GlobalVarName = "__PRETTY_FUNCTION__.";
break;
}
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 =
(isa<BlockDecl>(CurDecl)
? FnName.str()
: 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);
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() != 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->isSignedIntegerOrEnumerationType();
// 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, Int32Ty, IdxSigned, "vidx");
return LValue::MakeVectorElt(LHS.getAddress(), Idx,
E->getBase()->getType());
}
// Extend or truncate the index type to 32 or 64-bits.
if (Idx->getType() != IntPtrTy)
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() == 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;
CharUnits ArrayAlignment;
if (const VariableArrayType *vla =
getContext().getAsVariableArrayType(E->getType())) {
// The base must be a pointer, which is not an aggregate. Emit
// it. It needs to be emitted first in case it's what captures
// the VLA bounds.
Address = EmitScalarExpr(E->getBase());
// The element count here is the total number of non-VLA elements.
llvm::Value *numElements = getVLASize(vla).first;
// Effectively, the multiply by the VLA size is part of the GEP.
// GEP indexes are signed, and scaling an index isn't permitted to
// signed-overflow, so we use the same semantics for our explicit
// multiply. We suppress this if overflow is not undefined behavior.
if (getLangOptions().isSignedOverflowDefined()) {
Idx = Builder.CreateMul(Idx, numElements);
Address = Builder.CreateGEP(Address, Idx, "arrayidx");
} else {
Idx = Builder.CreateNSWMul(Idx, numElements);
Address = Builder.CreateInBoundsGEP(Address, 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);
// The base must be a pointer, which is not an aggregate. Emit it.
llvm::Value *Base = EmitScalarExpr(E->getBase());
Address = EmitCastToVoidPtr(Base);
Address = Builder.CreateGEP(Address, 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!");
LValue ArrayLV = EmitLValue(Array);
llvm::Value *ArrayPtr = ArrayLV.getAddress();
llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0);
llvm::Value *Args[] = { Zero, Idx };
// Propagate the alignment from the array itself to the result.
ArrayAlignment = ArrayLV.getAlignment();
if (getContext().getLangOptions().isSignedOverflowDefined())
Address = Builder.CreateGEP(ArrayPtr, Args, "arrayidx");
else
Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, "arrayidx");
} else {
// The base must be a pointer, which is not an aggregate. Emit it.
llvm::Value *Base = EmitScalarExpr(E->getBase());
if (getContext().getLangOptions().isSignedOverflowDefined())
Address = Builder.CreateGEP(Base, Idx, "arrayidx");
else
Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx");
}
QualType T = E->getBase()->getType()->getPointeeType();
assert(!T.isNull() &&
"CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type");
// Limit the alignment to that of the result type.
LValue LV;
if (!ArrayAlignment.isZero()) {
CharUnits Align = getContext().getTypeAlignInChars(T);
ArrayAlignment = std::min(Align, ArrayAlignment);
LV = MakeAddrLValue(Address, T, ArrayAlignment);
} else {
LV = MakeNaturalAlignAddrLValue(Address, T);
}
LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace());
if (getContext().getLangOptions().ObjC1 &&
getContext().getLangOptions().getGC() != LangOptions::NonGC) {
LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
setObjCGCLValueClass(getContext(), E, LV);
}
return LV;
}
static
llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext,
SmallVector<unsigned, 4> &Elts) {
SmallVector<llvm::Constant*, 4> CElts;
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);
}
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()->isGLValue()) {
// 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()->isVectorType() &&
"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());
}
QualType type =
E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
// Encode the element access list into a vector of unsigned indices.
SmallVector<unsigned, 4> Indices;
E->getEncodedElementAccess(Indices);
if (Base.isSimple()) {
llvm::Constant *CV = GenerateConstantVector(getLLVMContext(), Indices);
return LValue::MakeExtVectorElt(Base.getAddress(), CV, type);
}
assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
llvm::Constant *BaseElts = Base.getExtVectorElts();
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);
return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV, type);
}
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 {
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);
llvm_unreachable("Unhandled member declaration!");
}
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().withCVRQualifiers(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 IndirectFieldDecl *Field,
unsigned CVRQualifiers) {
IndirectFieldDecl::chain_iterator I = Field->chain_begin(),
IEnd = Field->chain_end();
while (true) {
LValue LV = EmitLValueForField(BaseValue, cast<FieldDecl>(*I),
CVRQualifiers);
if (++I == IEnd) return LV;
assert(LV.isSimple());
BaseValue = LV.getAddress();
CVRQualifiers |= LV.getVRQualifiers();
}
}
LValue CodeGenFunction::EmitLValueForField(llvm::Value *baseAddr,
const FieldDecl *field,
unsigned cvr) {
if (field->isBitField())
return EmitLValueForBitfield(baseAddr, field, cvr);
const RecordDecl *rec = field->getParent();
QualType type = field->getType();
CharUnits alignment = getContext().getDeclAlign(field);
bool mayAlias = rec->hasAttr<MayAliasAttr>();
llvm::Value *addr = baseAddr;
if (rec->isUnion()) {
// For unions, there is no pointer adjustment.
assert(!type->isReferenceType() && "union has reference member");
} else {
// For structs, we GEP to the field that the record layout suggests.
unsigned idx = CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
addr = Builder.CreateStructGEP(addr, idx, field->getName());
// If this is a reference field, load the reference right now.
if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
if (cvr & Qualifiers::Volatile) load->setVolatile(true);
load->setAlignment(alignment.getQuantity());
if (CGM.shouldUseTBAA()) {
llvm::MDNode *tbaa;
if (mayAlias)
tbaa = CGM.getTBAAInfo(getContext().CharTy);
else
tbaa = CGM.getTBAAInfo(type);
CGM.DecorateInstruction(load, tbaa);
}
addr = load;
mayAlias = false;
type = refType->getPointeeType();
if (type->isIncompleteType())
alignment = CharUnits();
else
alignment = getContext().getTypeAlignInChars(type);
cvr = 0; // qualifiers don't recursively apply to referencee
}
}
// Make sure that the address is pointing to the right type. This is critical
// for both unions and structs. A union needs a bitcast, a struct element
// will need a bitcast if the LLVM type laid out doesn't match the desired
// type.
addr = EmitBitCastOfLValueToProperType(*this, addr,
CGM.getTypes().ConvertTypeForMem(type),
field->getName());
if (field->hasAttr<AnnotateAttr>())
addr = EmitFieldAnnotations(field, addr);
LValue LV = MakeAddrLValue(addr, type, alignment);
LV.getQuals().addCVRQualifiers(cvr);
// __weak attribute on a field is ignored.
if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
LV.getQuals().removeObjCGCAttr();
// Fields of may_alias structs act like 'char' for TBAA purposes.
// FIXME: this should get propagated down through anonymous structs
// and unions.
if (mayAlias && LV.getTBAAInfo())
LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
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);
assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs");
// Make sure that the address is pointing to the right type. This is critical
// for both unions and structs. A union needs a bitcast, a struct element
// will need a bitcast if the LLVM type laid out doesn't match the desired
// type.
llvm::Type *llvmType = ConvertTypeForMem(FieldType);
unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
V = Builder.CreateBitCast(V, llvmType->getPointerTo(AS));
CharUnits Alignment = getContext().getDeclAlign(Field);
return MakeAddrLValue(V, FieldType, Alignment);
}
LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
if (E->isFileScope()) {
llvm::Value *GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
return MakeAddrLValue(GlobalPtr, E->getType());
}
llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
const Expr *InitExpr = E->getInitializer();
LValue Result = MakeAddrLValue(DeclPtr, E->getType());
EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
/*Init*/ true);
return Result;
}
LValue CodeGenFunction::
EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
if (!expr->isGLValue()) {
// ?: here should be an aggregate.
assert((hasAggregateLLVMType(expr->getType()) &&
!expr->getType()->isAnyComplexType()) &&
"Unexpected conditional operator!");
return EmitAggExprToLValue(expr);
}
const Expr *condExpr = expr->getCond();
bool CondExprBool;
if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
if (!CondExprBool) std::swap(live, dead);
if (!ContainsLabel(dead))
return EmitLValue(live);
}
OpaqueValueMapping binding(*this, expr);
llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
ConditionalEvaluation eval(*this);
EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock);
// Any temporaries created here are conditional.
EmitBlock(lhsBlock);
eval.begin(*this);
LValue lhs = EmitLValue(expr->getTrueExpr());
eval.end(*this);
if (!lhs.isSimple())
return EmitUnsupportedLValue(expr, "conditional operator");
lhsBlock = Builder.GetInsertBlock();
Builder.CreateBr(contBlock);
// Any temporaries created here are conditional.
EmitBlock(rhsBlock);
eval.begin(*this);
LValue rhs = EmitLValue(expr->getFalseExpr());
eval.end(*this);
if (!rhs.isSimple())
return EmitUnsupportedLValue(expr, "conditional operator");
rhsBlock = Builder.GetInsertBlock();
EmitBlock(contBlock);
llvm::PHINode *phi = Builder.CreatePHI(lhs.getAddress()->getType(), 2,
"cond-lvalue");
phi->addIncoming(lhs.getAddress(), lhsBlock);
phi->addIncoming(rhs.getAddress(), rhsBlock);
return MakeAddrLValue(phi, expr->getType());
}
/// 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 CK_ToVoid:
return EmitUnsupportedLValue(E, "unexpected cast lvalue");
case CK_Dependent:
llvm_unreachable("dependent cast kind in IR gen!");
// These two casts are currently treated as no-ops, although they could
// potentially be real operations depending on the target's ABI.
case CK_NonAtomicToAtomic:
case CK_AtomicToNonAtomic:
case CK_NoOp:
case CK_LValueToRValue:
if (!E->getSubExpr()->Classify(getContext()).isPRValue()
|| E->getType()->isRecordType())
return EmitLValue(E->getSubExpr());
// Fall through to synthesize a temporary.
case CK_BitCast:
case CK_ArrayToPointerDecay:
case CK_FunctionToPointerDecay:
case CK_NullToMemberPointer:
case CK_NullToPointer:
case CK_IntegralToPointer:
case CK_PointerToIntegral:
case CK_PointerToBoolean:
case CK_VectorSplat:
case CK_IntegralCast:
case CK_IntegralToBoolean:
case CK_IntegralToFloating:
case CK_FloatingToIntegral:
case CK_FloatingToBoolean:
case CK_FloatingCast:
case CK_FloatingRealToComplex:
case CK_FloatingComplexToReal:
case CK_FloatingComplexToBoolean:
case CK_FloatingComplexCast:
case CK_FloatingComplexToIntegralComplex:
case CK_IntegralRealToComplex:
case CK_IntegralComplexToReal:
case CK_IntegralComplexToBoolean:
case CK_IntegralComplexCast:
case CK_IntegralComplexToFloatingComplex:
case CK_DerivedToBaseMemberPointer:
case CK_BaseToDerivedMemberPointer:
case CK_MemberPointerToBoolean:
case CK_AnyPointerToBlockPointerCast:
case CK_ARCProduceObject:
case CK_ARCConsumeObject:
case CK_ARCReclaimReturnedObject:
case CK_ARCExtendBlockObject: {
// 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, E->getType().getQualifiers(), false);
return MakeAddrLValue(V, E->getType());
}
case 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 CK_ConstructorConversion:
case CK_UserDefinedConversion:
case CK_CPointerToObjCPointerCast:
case CK_BlockPointerToObjCPointerCast:
return EmitLValue(E->getSubExpr());
case CK_UncheckedDerivedToBase:
case CK_DerivedToBase: {
const RecordType *DerivedClassTy =
E->getSubExpr()->getType()->getAs<RecordType>();
CXXRecordDecl *DerivedClassDecl =
cast<CXXRecordDecl>(DerivedClassTy->getDecl());
LValue LV = EmitLValue(E->getSubExpr());
llvm::Value *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 CK_ToUnion:
return EmitAggExprToLValue(E);
case 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 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 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;
}
LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
assert(OpaqueValueMappingData::shouldBindAsLValue(e));
return getOpaqueLValueMapping(e);
}
LValue CodeGenFunction::EmitMaterializeTemporaryExpr(
const MaterializeTemporaryExpr *E) {
RValue RV = EmitReferenceBindingToExpr(E, /*InitializedDecl=*/0);
return MakeAddrLValue(RV.getScalarVal(), E->getType());
}
//===--------------------------------------------------------------------===//
// Expression Emission
//===--------------------------------------------------------------------===//
RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
ReturnValueSlot ReturnValue) {
if (CGDebugInfo *DI = getDebugInfo())
DI->EmitLocation(Builder, E->getLocStart());
// 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);
if (const CUDAKernelCallExpr *CE = dyn_cast<CUDAKernelCallExpr>(E))
return EmitCUDAKernelCallExpr(CE, ReturnValue);
const Decl *TargetDecl = E->getCalleeDecl();
if (const FunctionDecl *FD = dyn_cast_or_null<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 (const CXXPseudoDestructorExpr *PseudoDtor
= dyn_cast<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
QualType DestroyedType = PseudoDtor->getDestroyedType();
if (getContext().getLangOptions().ObjCAutoRefCount &&
DestroyedType->isObjCLifetimeType() &&
(DestroyedType.getObjCLifetime() == Qualifiers::OCL_Strong ||
DestroyedType.getObjCLifetime() == Qualifiers::OCL_Weak)) {
// Automatic Reference Counting:
// If the pseudo-expression names a retainable object with weak or
// strong lifetime, the object shall be released.
Expr *BaseExpr = PseudoDtor->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 (PseudoDtor->isArrow()) {
BaseValue = EmitScalarExpr(BaseExpr);
const PointerType *PTy = BaseExpr->getType()->getAs<PointerType>();
BaseQuals = PTy->getPointeeType().getQualifiers();
} else {
LValue BaseLV = EmitLValue(BaseExpr);
BaseValue = BaseLV.getAddress();
QualType BaseTy = BaseExpr->getType();
BaseQuals = BaseTy.getQualifiers();
}
switch (PseudoDtor->getDestroyedType().getObjCLifetime()) {
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
case Qualifiers::OCL_Autoreleasing:
break;
case Qualifiers::OCL_Strong:
EmitARCRelease(Builder.CreateLoad(BaseValue,
PseudoDtor->getDestroyedType().isVolatileQualified()),
/*precise*/ true);
break;
case Qualifiers::OCL_Weak:
EmitARCDestroyWeak(BaseValue);
break;
}
} else {
// 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() == BO_Comma) {
EmitIgnoredExpr(E->getLHS());
EnsureInsertPoint();
return EmitLValue(E->getRHS());
}
if (E->getOpcode() == BO_PtrMemD ||
E->getOpcode() == BO_PtrMemI)
return EmitPointerToDataMemberBinaryExpr(E);
assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
// Note that in all of these cases, __block variables need the RHS
// evaluated first just in case the variable gets moved by the RHS.
if (!hasAggregateLLVMType(E->getType())) {
switch (E->getLHS()->getType().getObjCLifetime()) {
case Qualifiers::OCL_Strong:
return EmitARCStoreStrong(E, /*ignored*/ false).first;
case Qualifiers::OCL_Autoreleasing:
return EmitARCStoreAutoreleasing(E).first;
// No reason to do any of these differently.
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
case Qualifiers::OCL_Weak:
break;
}
RValue RV = EmitAnyExpr(E->getRHS());
LValue LV = EmitLValue(E->getLHS());
EmitStoreThroughLValue(RV, LV);
return LV;
}
if (E->getType()->isAnyComplexType())
return EmitComplexAssignmentLValue(E);
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) {
assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
&& "binding l-value to type which needs a temporary");
AggValueSlot Slot = CreateAggTemp(E->getType());
EmitCXXConstructExpr(E, Slot);
return MakeAddrLValue(Slot.getAddr(), E->getType());
}
LValue
CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType());
}
LValue
CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
Slot.setExternallyDestructed();
EmitAggExpr(E->getSubExpr(), Slot);
EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddr());
return MakeAddrLValue(Slot.getAddr(), E->getType());
}
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) {