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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 "CGCXXABI.h"
#include "CGCall.h"
#include "CGCleanup.h"
#include "CGDebugInfo.h"
#include "CGObjCRuntime.h"
#include "CGOpenMPRuntime.h"
#include "CGRecordLayout.h"
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "TargetInfo.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/Attr.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/NSAPI.h"
#include "clang/Frontend/CodeGenOptions.h"
#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/MDBuilder.h"
#include "llvm/Support/ConvertUTF.h"
#include "llvm/Support/MathExtras.h"
#include "llvm/Support/Path.h"
#include "llvm/Transforms/Utils/SanitizerStats.h"
#include <string>
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.
Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
const Twine &Name) {
auto Alloca = CreateTempAlloca(Ty, Name);
Alloca->setAlignment(Align.getQuantity());
return Address(Alloca, Align);
}
/// CreateTempAlloca - This creates a alloca and inserts it into the entry
/// block.
llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
const Twine &Name) {
return new llvm::AllocaInst(Ty, nullptr, Name, AllocaInsertPt);
}
/// CreateDefaultAlignTempAlloca - This creates an alloca with the
/// default alignment of the corresponding LLVM type, which is *not*
/// guaranteed to be related in any way to the expected alignment of
/// an AST type that might have been lowered to Ty.
Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
const Twine &Name) {
CharUnits Align =
CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
return CreateTempAlloca(Ty, Align, Name);
}
void CodeGenFunction::InitTempAlloca(Address Var, llvm::Value *Init) {
assert(isa<llvm::AllocaInst>(Var.getPointer()));
auto *Store = new llvm::StoreInst(Init, Var.getPointer());
Store->setAlignment(Var.getAlignment().getQuantity());
llvm::BasicBlock *Block = AllocaInsertPt->getParent();
Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
}
Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
CharUnits Align = getContext().getTypeAlignInChars(Ty);
return CreateTempAlloca(ConvertType(Ty), Align, Name);
}
Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name) {
// FIXME: Should we prefer the preferred type alignment here?
return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name);
}
Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
const Twine &Name) {
return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name);
}
/// 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) {
PGO.setCurrentStmt(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;
SourceLocation Loc = E->getExprLoc();
if (!E->getType()->isAnyComplexType())
return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
Loc);
}
/// 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) {
switch (getEvaluationKind(E->getType())) {
case TEK_Scalar:
return RValue::get(EmitScalarExpr(E, ignoreResult));
case TEK_Complex:
return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
case TEK_Aggregate:
if (!ignoreResult && aggSlot.isIgnored())
aggSlot = CreateAggTemp(E->getType(), "agg-temp");
EmitAggExpr(E, aggSlot);
return aggSlot.asRValue();
}
llvm_unreachable("bad evaluation kind");
}
/// 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 (hasAggregateEvaluationKind(E->getType()))
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,
Address Location,
Qualifiers Quals,
bool IsInit) {
// FIXME: This function should take an LValue as an argument.
switch (getEvaluationKind(E->getType())) {
case TEK_Complex:
EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
/*isInit*/ false);
return;
case TEK_Aggregate: {
EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
AggValueSlot::IsDestructed_t(IsInit),
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsAliased_t(!IsInit)));
return;
}
case TEK_Scalar: {
RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
LValue LV = MakeAddrLValue(Location, E->getType());
EmitStoreThroughLValue(RV, LV);
return;
}
}
llvm_unreachable("bad evaluation kind");
}
static void
pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
const Expr *E, Address ReferenceTemporary) {
// 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.
//
// FIXME: This should be looking at E, not M.
if (auto Lifetime = M->getType().getObjCLifetime()) {
switch (Lifetime) {
case Qualifiers::OCL_None:
case Qualifiers::OCL_ExplicitNone:
// Carry on to normal cleanup handling.
break;
case Qualifiers::OCL_Autoreleasing:
// Nothing to do; cleaned up by an autorelease pool.
return;
case Qualifiers::OCL_Strong:
case Qualifiers::OCL_Weak:
switch (StorageDuration Duration = M->getStorageDuration()) {
case SD_Static:
// Note: we intentionally do not register a cleanup to release
// the object on program termination.
return;
case SD_Thread:
// FIXME: We should probably register a cleanup in this case.
return;
case SD_Automatic:
case SD_FullExpression:
CodeGenFunction::Destroyer *Destroy;
CleanupKind CleanupKind;
if (Lifetime == Qualifiers::OCL_Strong) {
const ValueDecl *VD = M->getExtendingDecl();
bool Precise =
VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
CleanupKind = CGF.getARCCleanupKind();
Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
: &CodeGenFunction::destroyARCStrongImprecise;
} else {
// __weak objects always get EH cleanups; otherwise, exceptions
// could cause really nasty crashes instead of mere leaks.
CleanupKind = NormalAndEHCleanup;
Destroy = &CodeGenFunction::destroyARCWeak;
}
if (Duration == SD_FullExpression)
CGF.pushDestroy(CleanupKind, ReferenceTemporary,
M->getType(), *Destroy,
CleanupKind & EHCleanup);
else
CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
M->getType(),
*Destroy, CleanupKind & EHCleanup);
return;
case SD_Dynamic:
llvm_unreachable("temporary cannot have dynamic storage duration");
}
llvm_unreachable("unknown storage duration");
}
}
CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
if (const RecordType *RT =
E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
// Get the destructor for the reference temporary.
auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
if (!ClassDecl->hasTrivialDestructor())
ReferenceTemporaryDtor = ClassDecl->getDestructor();
}
if (!ReferenceTemporaryDtor)
return;
// Call the destructor for the temporary.
switch (M->getStorageDuration()) {
case SD_Static:
case SD_Thread: {
llvm::Constant *CleanupFn;
llvm::Constant *CleanupArg;
if (E->getType()->isArrayType()) {
CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
ReferenceTemporary, E->getType(),
CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
} else {
CleanupFn = CGF.CGM.getAddrOfCXXStructor(ReferenceTemporaryDtor,
StructorType::Complete);
CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
}
CGF.CGM.getCXXABI().registerGlobalDtor(
CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
break;
}
case SD_FullExpression:
CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
CodeGenFunction::destroyCXXObject,
CGF.getLangOpts().Exceptions);
break;
case SD_Automatic:
CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
ReferenceTemporary, E->getType(),
CodeGenFunction::destroyCXXObject,
CGF.getLangOpts().Exceptions);
break;
case SD_Dynamic:
llvm_unreachable("temporary cannot have dynamic storage duration");
}
}
static Address
createReferenceTemporary(CodeGenFunction &CGF,
const MaterializeTemporaryExpr *M, const Expr *Inner) {
switch (M->getStorageDuration()) {
case SD_FullExpression:
case SD_Automatic: {
// If we have a constant temporary array or record try to promote it into a
// constant global under the same rules a normal constant would've been
// promoted. This is easier on the optimizer and generally emits fewer
// instructions.
QualType Ty = Inner->getType();
if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
(Ty->isArrayType() || Ty->isRecordType()) &&
CGF.CGM.isTypeConstant(Ty, true))
if (llvm::Constant *Init = CGF.CGM.EmitConstantExpr(Inner, Ty, &CGF)) {
auto *GV = new llvm::GlobalVariable(
CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp");
CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
GV->setAlignment(alignment.getQuantity());
// FIXME: Should we put the new global into a COMDAT?
return Address(GV, alignment);
}
return CGF.CreateMemTemp(Ty, "ref.tmp");
}
case SD_Thread:
case SD_Static:
return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
case SD_Dynamic:
llvm_unreachable("temporary can't have dynamic storage duration");
}
llvm_unreachable("unknown storage duration");
}
LValue CodeGenFunction::
EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
const Expr *E = M->GetTemporaryExpr();
// FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
// as that will cause the lifetime adjustment to be lost for ARC
auto ownership = M->getType().getObjCLifetime();
if (ownership != Qualifiers::OCL_None &&
ownership != Qualifiers::OCL_ExplicitNone) {
Address Object = createReferenceTemporary(*this, M, E);
if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
Object = Address(llvm::ConstantExpr::getBitCast(Var,
ConvertTypeForMem(E->getType())
->getPointerTo(Object.getAddressSpace())),
Object.getAlignment());
// createReferenceTemporary will promote the temporary to a global with a
// constant initializer if it can. It can only do this to a value of
// ARC-manageable type if the value is global and therefore "immune" to
// ref-counting operations. Therefore we have no need to emit either a
// dynamic initialization or a cleanup and we can just return the address
// of the temporary.
if (Var->hasInitializer())
return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
Var->setInitializer(CGM.EmitNullConstant(E->getType()));
}
LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
AlignmentSource::Decl);
switch (getEvaluationKind(E->getType())) {
default: llvm_unreachable("expected scalar or aggregate expression");
case TEK_Scalar:
EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
break;
case TEK_Aggregate: {
EmitAggExpr(E, AggValueSlot::forAddr(Object,
E->getType().getQualifiers(),
AggValueSlot::IsDestructed,
AggValueSlot::DoesNotNeedGCBarriers,
AggValueSlot::IsNotAliased));
break;
}
}
pushTemporaryCleanup(*this, M, E, Object);
return RefTempDst;
}
SmallVector<const Expr *, 2> CommaLHSs;
SmallVector<SubobjectAdjustment, 2> Adjustments;
E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
for (const auto &Ignored : CommaLHSs)
EmitIgnoredExpr(Ignored);
if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
if (opaque->getType()->isRecordType()) {
assert(Adjustments.empty());
return EmitOpaqueValueLValue(opaque);
}
}
// Create and initialize the reference temporary.
Address Object = createReferenceTemporary(*this, M, E);
if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
Object = Address(llvm::ConstantExpr::getBitCast(
Var, ConvertTypeForMem(E->getType())->getPointerTo()),
Object.getAlignment());
// If the temporary is a global and has a constant initializer or is a
// constant temporary that we promoted to a global, we may have already
// initialized it.
if (!Var->hasInitializer()) {
Var->setInitializer(CGM.EmitNullConstant(E->getType()));
EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
}
} else {
switch (M->getStorageDuration()) {
case SD_Automatic:
case SD_FullExpression:
if (auto *Size = EmitLifetimeStart(
CGM.getDataLayout().getTypeAllocSize(Object.getElementType()),
Object.getPointer())) {
if (M->getStorageDuration() == SD_Automatic)
pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
Object, Size);
else
pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Object,
Size);
}
break;
default:
break;
}
EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
}
pushTemporaryCleanup(*this, M, E, Object);
// 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.
for (unsigned I = Adjustments.size(); I != 0; --I) {
SubobjectAdjustment &Adjustment = Adjustments[I-1];
switch (Adjustment.Kind) {
case SubobjectAdjustment::DerivedToBaseAdjustment:
Object =
GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
Adjustment.DerivedToBase.BasePath->path_begin(),
Adjustment.DerivedToBase.BasePath->path_end(),
/*NullCheckValue=*/ false, E->getExprLoc());
break;
case SubobjectAdjustment::FieldAdjustment: {
LValue LV = MakeAddrLValue(Object, E->getType(),
AlignmentSource::Decl);
LV = EmitLValueForField(LV, Adjustment.Field);
assert(LV.isSimple() &&
"materialized temporary field is not a simple lvalue");
Object = LV.getAddress();
break;
}
case SubobjectAdjustment::MemberPointerAdjustment: {
llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
Adjustment.Ptr.MPT);
break;
}
}
}
return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
}
RValue
CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
// Emit the expression as an lvalue.
LValue LV = EmitLValue(E);
assert(LV.isSimple());
llvm::Value *Value = LV.getPointer();
if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
// C++11 [dcl.ref]p5 (as amended by core issue 453):
// If a glvalue to which a reference is directly bound designates neither
// an existing object or function of an appropriate type nor a region of
// storage of suitable size and alignment to contain an object of the
// reference's type, the behavior is undefined.
QualType Ty = E->getType();
EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
}
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) {
return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
->getZExtValue();
}
/// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
llvm::Value *High) {
llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
llvm::Value *K47 = Builder.getInt64(47);
llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
return Builder.CreateMul(B1, KMul);
}
bool CodeGenFunction::sanitizePerformTypeCheck() const {
return SanOpts.has(SanitizerKind::Null) |
SanOpts.has(SanitizerKind::Alignment) |
SanOpts.has(SanitizerKind::ObjectSize) |
SanOpts.has(SanitizerKind::Vptr);
}
void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
llvm::Value *Ptr, QualType Ty,
CharUnits Alignment, bool SkipNullCheck) {
if (!sanitizePerformTypeCheck())
return;
// Don't check pointers outside the default address space. The null check
// isn't correct, the object-size check isn't supported by LLVM, and we can't
// communicate the addresses to the runtime handler for the vptr check.
if (Ptr->getType()->getPointerAddressSpace())
return;
SanitizerScope SanScope(this);
SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
llvm::BasicBlock *Done = nullptr;
bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
TCK == TCK_UpcastToVirtualBase;
if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
!SkipNullCheck) {
// The glvalue must not be an empty glvalue.
llvm::Value *IsNonNull = Builder.CreateIsNotNull(Ptr);
if (AllowNullPointers) {
// When performing pointer casts, it's OK if the value is null.
// Skip the remaining checks in that case.
Done = createBasicBlock("null");
llvm::BasicBlock *Rest = createBasicBlock("not.null");
Builder.CreateCondBr(IsNonNull, Rest, Done);
EmitBlock(Rest);
} else {
Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
}
}
if (SanOpts.has(SanitizerKind::ObjectSize) && !Ty->isIncompleteType()) {
uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
// The glvalue must refer to a large enough storage region.
// FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
// to check this.
// FIXME: Get object address space
llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
llvm::Value *Min = Builder.getFalse();
llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
llvm::Value *LargeEnough =
Builder.CreateICmpUGE(Builder.CreateCall(F, {CastAddr, Min}),
llvm::ConstantInt::get(IntPtrTy, Size));
Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
}
uint64_t AlignVal = 0;
if (SanOpts.has(SanitizerKind::Alignment)) {
AlignVal = Alignment.getQuantity();
if (!Ty->isIncompleteType() && !AlignVal)
AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
// The glvalue must be suitably aligned.
if (AlignVal) {
llvm::Value *Align =
Builder.CreateAnd(Builder.CreatePtrToInt(Ptr, IntPtrTy),
llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
llvm::Value *Aligned =
Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
}
}
if (Checks.size() > 0) {
// Make sure we're not losing information. Alignment needs to be a power of
// 2
assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
llvm::Constant *StaticData[] = {
EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
llvm::ConstantInt::get(Int8Ty, TCK)};
EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData, Ptr);
}
// If possible, check that the vptr indicates that there is a subobject of
// type Ty at offset zero within this object.
//
// C++11 [basic.life]p5,6:
// [For storage which does not refer to an object within its lifetime]
// The program has undefined behavior if:
// -- the [pointer or glvalue] is used to access a non-static data member
// or call a non-static member function
CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
if (SanOpts.has(SanitizerKind::Vptr) &&
(TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
TCK == TCK_UpcastToVirtualBase) &&
RD && RD->hasDefinition() && RD->isDynamicClass()) {
// Compute a hash of the mangled name of the type.
//
// FIXME: This is not guaranteed to be deterministic! Move to a
// fingerprinting mechanism once LLVM provides one. For the time
// being the implementation happens to be deterministic.
SmallString<64> MangledName;
llvm::raw_svector_ostream Out(MangledName);
CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
Out);
// Blacklist based on the mangled type.
if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
Out.str())) {
llvm::hash_code TypeHash = hash_value(Out.str());
// Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
Hash = Builder.CreateTrunc(Hash, IntPtrTy);
// Look the hash up in our cache.
const int CacheSize = 128;
llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
"__ubsan_vptr_type_cache");
llvm::Value *Slot = Builder.CreateAnd(Hash,
llvm::ConstantInt::get(IntPtrTy,
CacheSize-1));
llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
llvm::Value *CacheVal =
Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
getPointerAlign());
// If the hash isn't in the cache, call a runtime handler to perform the
// hard work of checking whether the vptr is for an object of the right
// type. This will either fill in the cache and return, or produce a
// diagnostic.
llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
llvm::Constant *StaticData[] = {
EmitCheckSourceLocation(Loc),
EmitCheckTypeDescriptor(Ty),
CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
llvm::ConstantInt::get(Int8Ty, TCK)
};
llvm::Value *DynamicData[] = { Ptr, Hash };
EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
SanitizerHandler::DynamicTypeCacheMiss, StaticData,
DynamicData);
}
}
if (Done) {
Builder.CreateBr(Done);
EmitBlock(Done);
}
}
/// Determine whether this expression refers to a flexible array member in a
/// struct. We disable array bounds checks for such members.
static bool isFlexibleArrayMemberExpr(const Expr *E) {
// For compatibility with existing code, we treat arrays of length 0 or
// 1 as flexible array members.
const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
if (CAT->getSize().ugt(1))
return false;
} else if (!isa<IncompleteArrayType>(AT))
return false;
E = E->IgnoreParens();
// A flexible array member must be the last member in the class.
if (const auto *ME = dyn_cast<MemberExpr>(E)) {
// FIXME: If the base type of the member expr is not FD->getParent(),
// this should not be treated as a flexible array member access.
if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
RecordDecl::field_iterator FI(
DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
return ++FI == FD->getParent()->field_end();
}
} else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
return IRE->getDecl()->getNextIvar() == nullptr;
}
return false;
}
/// If Base is known to point to the start of an array, return the length of
/// that array. Return 0 if the length cannot be determined.
static llvm::Value *getArrayIndexingBound(
CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
// For the vector indexing extension, the bound is the number of elements.
if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
IndexedType = Base->getType();
return CGF.Builder.getInt32(VT->getNumElements());
}
Base = Base->IgnoreParens();
if (const auto *CE = dyn_cast<CastExpr>(Base)) {
if (CE->getCastKind() == CK_ArrayToPointerDecay &&
!isFlexibleArrayMemberExpr(CE->getSubExpr())) {
IndexedType = CE->getSubExpr()->getType();
const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
return CGF.Builder.getInt(CAT->getSize());
else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
return CGF.getVLASize(VAT).first;
}
}
return nullptr;
}
void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
llvm::Value *Index, QualType IndexType,
bool Accessed) {
assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
"should not be called unless adding bounds checks");
SanitizerScope SanScope(this);
QualType IndexedType;
llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
if (!Bound)
return;
bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
llvm::Constant *StaticData[] = {
EmitCheckSourceLocation(E->getExprLoc()),
EmitCheckTypeDescriptor(IndexedType),
EmitCheckTypeDescriptor(IndexType)
};
llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
: Builder.CreateICmpULE(IndexVal, BoundVal);
EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
SanitizerHandler::OutOfBounds, StaticData, Index);
}
CodeGenFunction::ComplexPairTy CodeGenFunction::
EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
bool isInc, bool isPre) {
ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
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.
EmitStoreOfComplex(IncVal, LV, /*init*/ false);
// If this is a postinc, return the value read from memory, otherwise use the
// updated value.
return isPre ? IncVal : InVal;
}
void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
CodeGenFunction *CGF) {
// Bind VLAs in the cast type.
if (CGF && E->getType()->isVariablyModifiedType())
CGF->EmitVariablyModifiedType(E->getType());
if (CGDebugInfo *DI = getModuleDebugInfo())
DI->EmitExplicitCastType(E->getType());
}
//===----------------------------------------------------------------------===//
// LValue Expression Emission
//===----------------------------------------------------------------------===//
/// EmitPointerWithAlignment - Given an expression of pointer type, try to
/// derive a more accurate bound on the alignment of the pointer.
Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
AlignmentSource *Source) {
// We allow this with ObjC object pointers because of fragile ABIs.
assert(E->getType()->isPointerType() ||
E->getType()->isObjCObjectPointerType());
E = E->IgnoreParens();
// Casts:
if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
CGM.EmitExplicitCastExprType(ECE, this);
switch (CE->getCastKind()) {
// Non-converting casts (but not C's implicit conversion from void*).
case CK_BitCast:
case CK_NoOp:
if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
if (PtrTy->getPointeeType()->isVoidType())
break;
AlignmentSource InnerSource;
Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), &InnerSource);
if (Source) *Source = InnerSource;
// If this is an explicit bitcast, and the source l-value is
// opaque, honor the alignment of the casted-to type.
if (isa<ExplicitCastExpr>(CE) &&
InnerSource != AlignmentSource::Decl) {
Addr = Address(Addr.getPointer(),
getNaturalPointeeTypeAlignment(E->getType(), Source));
}
if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
CE->getCastKind() == CK_BitCast) {
if (auto PT = E->getType()->getAs<PointerType>())
EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
/*MayBeNull=*/true,
CodeGenFunction::CFITCK_UnrelatedCast,
CE->getLocStart());
}
return Builder.CreateBitCast(Addr, ConvertType(E->getType()));
}
break;
// Array-to-pointer decay.
case CK_ArrayToPointerDecay:
return EmitArrayToPointerDecay(CE->getSubExpr(), Source);
// Derived-to-base conversions.
case CK_UncheckedDerivedToBase:
case CK_DerivedToBase: {
Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), Source);
auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
return GetAddressOfBaseClass(Addr, Derived,
CE->path_begin(), CE->path_end(),
ShouldNullCheckClassCastValue(CE),
CE->getExprLoc());
}
// TODO: Is there any reason to treat base-to-derived conversions
// specially?
default:
break;
}
}
// Unary &.
if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
if (UO->getOpcode() == UO_AddrOf) {
LValue LV = EmitLValue(UO->getSubExpr());
if (Source) *Source = LV.getAlignmentSource();
return LV.getAddress();
}
}
// TODO: conditional operators, comma.
// Otherwise, use the alignment of the type.
CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), Source);
return Address(EmitScalarExpr(E), Align);
}
RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
if (Ty->isVoidType())
return RValue::get(nullptr);
switch (getEvaluationKind(Ty)) {
case TEK_Complex: {
llvm::Type *EltTy =
ConvertType(Ty->castAs<ComplexType>()->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.
case TEK_Aggregate: {
Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
return RValue::getAggregate(DestPtr);
}
case TEK_Scalar:
return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
}
llvm_unreachable("bad evaluation kind");
}
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(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
E->getType());
}
LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
LValue LV;
if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
else
LV = EmitLValue(E);
if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
E->getType(), LV.getAlignment());
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) {
ApplyDebugLocation DL(*this, 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: {
QualType Ty = E->getType();
if (const AtomicType *AT = Ty->getAs<AtomicType>())
Ty = AT->getValueType();
if (!Ty->isAnyComplexType())
return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
}
case Expr::CallExprClass:
case Expr::CXXMemberCallExprClass:
case Expr::CXXOperatorCallExprClass:
case Expr::UserDefinedLiteralClass:
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:
return EmitInitListLValue(cast<InitListExpr>(E));
case Expr::CXXTemporaryObjectExprClass:
case Expr::CXXConstructExprClass:
return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
case Expr::CXXBindTemporaryExprClass:
return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
case Expr::CXXUuidofExprClass:
return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
case Expr::LambdaExprClass:
return EmitLambdaLValue(cast<LambdaExpr>(E));
case Expr::ExprWithCleanupsClass: {
const auto *cleanups = cast<ExprWithCleanups>(E);
enterFullExpression(cleanups);
RunCleanupsScope Scope(*this);
return EmitLValue(cleanups->getSubExpr());
}
case Expr::CXXDefaultArgExprClass:
return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
case Expr::CXXDefaultInitExprClass: {
CXXDefaultInitExprScope Scope(*this);
return EmitLValue(cast<CXXDefaultInitExpr>(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::OMPArraySectionExprClass:
return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(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());
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));
}
}
/// Given an object of the given canonical type, can we safely copy a
/// value out of it based on its initializer?
static bool isConstantEmittableObjectType(QualType type) {
assert(type.isCanonical());
assert(!type->isReferenceType());
// Must be const-qualified but non-volatile.
Qualifiers qs = type.getLocalQualifiers();
if (!qs.hasConst() || qs.hasVolatile()) return false;
// Otherwise, all object types satisfy this except C++ classes with
// mutable subobjects or non-trivial copy/destroy behavior.
if (const auto *RT = dyn_cast<RecordType>(type))
if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
if (RD->hasMutableFields() || !RD->isTrivial())
return false;
return true;
}
/// Can we constant-emit a load of a reference to a variable of the
/// given type? This is different from predicates like
/// Decl::isUsableInConstantExpressions because we do want it to apply
/// in situations that don't necessarily satisfy the language's rules
/// for this (e.g. C++'s ODR-use rules). For example, we want to able
/// to do this with const float variables even if those variables
/// aren't marked 'constexpr'.
enum ConstantEmissionKind {
CEK_None,
CEK_AsReferenceOnly,
CEK_AsValueOrReference,
CEK_AsValueOnly
};
static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
type = type.getCanonicalType();
if (const auto *ref = dyn_cast<ReferenceType>(type)) {
if (isConstantEmittableObjectType(ref->getPointeeType()))
return CEK_AsValueOrReference;
return CEK_AsReferenceOnly;
}
if (isConstantEmittableObjectType(type))
return CEK_AsValueOnly;
return CEK_None;
}
/// Try to emit a reference to the given value without producing it as
/// an l-value. This is actually more than an optimization: we can't
/// produce an l-value for variables that we never actually captured
/// in a block or lambda, which means const int variables or constexpr
/// literals or similar.
CodeGenFunction::ConstantEmission
CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
ValueDecl *value = refExpr->getDecl();
// The value needs to be an enum constant or a constant variable.
ConstantEmissionKind CEK;
if (isa<ParmVarDecl>(value)) {
CEK = CEK_None;
} else if (auto *var = dyn_cast<VarDecl>(value)) {
CEK = checkVarTypeForConstantEmission(var->getType());
} else if (isa<EnumConstantDecl>(value)) {
CEK = CEK_AsValueOnly;
} else {
CEK = CEK_None;
}
if (CEK == CEK_None) return ConstantEmission();
Expr::EvalResult result;
bool resultIsReference;
QualType resultType;
// It's best to evaluate all the way as an r-value if that's permitted.
if (CEK != CEK_AsReferenceOnly &&
refExpr->EvaluateAsRValue(result, getContext())) {
resultIsReference = false;
resultType = refExpr->getType();
// Otherwise, try to evaluate as an l-value.
} else if (CEK != CEK_AsValueOnly &&
refExpr->EvaluateAsLValue(result, getContext())) {
resultIsReference = true;
resultType = value->getType();
// Failure.
} else {
return ConstantEmission();
}
// In any case, if the initializer has side-effects, abandon ship.
if (result.HasSideEffects)
return ConstantEmission();
// Emit as a constant.
llvm::Constant *C = CGM.EmitConstantValue(result.Val, resultType, this);
// Make sure we emit a debug reference to the global variable.
// This should probably fire even for
if (isa<VarDecl>(value)) {
if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
EmitDeclRefExprDbgValue(refExpr, result.Val);
} else {
assert(isa<EnumConstantDecl>(value));
EmitDeclRefExprDbgValue(refExpr, result.Val);
}
// If we emitted a reference constant, we need to dereference that.
if (resultIsReference)
return ConstantEmission::forReference(C);
return ConstantEmission::forValue(C);
}
llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
SourceLocation Loc) {
return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
lvalue.getType(), Loc, lvalue.getAlignmentSource(),
lvalue.getTBAAInfo(),
lvalue.getTBAABaseType(), lvalue.getTBAAOffset(),
lvalue.isNontemporal());
}
static bool hasBooleanRepresentation(QualType Ty) {
if (Ty->isBooleanType())
return true;
if (const EnumType *ET = Ty->getAs<EnumType>())
return ET->getDecl()->getIntegerType()->isBooleanType();
if (const AtomicType *AT = Ty->getAs<AtomicType>())
return hasBooleanRepresentation(AT->getValueType());
return false;
}
static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
llvm::APInt &Min, llvm::APInt &End,
bool StrictEnums, bool IsBool) {
const EnumType *ET = Ty->getAs<EnumType>();
bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
ET && !ET->getDecl()->isFixed();
if (!IsBool && !IsRegularCPlusPlusEnum)
return false;
if (IsBool) {
Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
} else {
const EnumDecl *ED = ET->getDecl();
llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
unsigned Bitwidth = LTy->getScalarSizeInBits();
unsigned NumNegativeBits = ED->getNumNegativeBits();
unsigned NumPositiveBits = ED->getNumPositiveBits();
if (NumNegativeBits) {
unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
assert(NumBits <= Bitwidth);
End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
Min = -End;
} else {
assert(NumPositiveBits <= Bitwidth);
End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
Min = llvm::APInt(Bitwidth, 0);
}
}
return true;
}
llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
llvm::APInt Min, End;
if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
hasBooleanRepresentation(Ty)))
return nullptr;
llvm::MDBuilder MDHelper(getLLVMContext());
return MDHelper.createRange(Min, End);
}
llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
QualType Ty,
SourceLocation Loc,
AlignmentSource AlignSource,
llvm::MDNode *TBAAInfo,
QualType TBAABaseType,
uint64_t TBAAOffset,
bool isNontemporal) {
// For better performance, handle vector loads differently.
if (Ty->isVectorType()) {
const llvm::Type *EltTy = Addr.getElementType();
const auto *VTy = cast<llvm::VectorType>(EltTy);
// Handle vectors of size 3 like size 4 for better performance.
if (VTy->getNumElements() == 3) {
// Bitcast to vec4 type.
llvm::VectorType *vec4Ty = llvm::VectorType::get(VTy->getElementType(),
4);
Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
// Now load value.
llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
// Shuffle vector to get vec3.
V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
{0, 1, 2}, "extractVec");
return EmitFromMemory(V, Ty);
}
}
// Atomic operations have to be done on integral types.
LValue AtomicLValue =
LValue::MakeAddr(Addr, Ty, getContext(), AlignSource, TBAAInfo);
if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
}
llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
if (isNontemporal) {
llvm::MDNode *Node = llvm::MDNode::get(
Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
}
if (TBAAInfo) {
llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
TBAAOffset);
if (TBAAPath)
CGM.DecorateInstructionWithTBAA(Load, TBAAPath,
false /*ConvertTypeToTag*/);
}
bool IsBool = hasBooleanRepresentation(Ty) ||
NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
bool NeedsBoolCheck = SanOpts.has(SanitizerKind::Bool) && IsBool;
bool NeedsEnumCheck =
SanOpts.has(SanitizerKind::Enum) && Ty->getAs<EnumType>();
if (NeedsBoolCheck || NeedsEnumCheck) {
SanitizerScope SanScope(this);
llvm::APInt Min, End;
if (getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool)) {
--End;
llvm::Value *Check;
if (!Min)
Check = Builder.CreateICmpULE(
Load, llvm::ConstantInt::get(getLLVMContext(), End));
else {
llvm::Value *Upper = Builder.CreateICmpSLE(
Load, llvm::ConstantInt::get(getLLVMContext(), End));
llvm::Value *Lower = Builder.CreateICmpSGE(
Load, llvm::ConstantInt::get(getLLVMContext(), Min));
Check = Builder.CreateAnd(Upper, Lower);
}
llvm::Constant *StaticArgs[] = {
EmitCheckSourceLocation(Loc),
EmitCheckTypeDescriptor(Ty)
};
SanitizerMask Kind = NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
StaticArgs, EmitCheckValue(Load));
}
} else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
return EmitFromMemory(Load, Ty);
}
llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
// Bool has a different representation in memory than in registers.
if (hasBooleanRepresentation(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, ConvertTypeForMem(Ty), "frombool");
assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
"wrong value rep of bool");
}
return Value;
}
llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
// Bool has a different representation in memory than in registers.
if (hasBooleanRepresentation(Ty)) {
assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
"wrong value rep of bool");
return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
}
return Value;
}
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
bool Volatile, QualType Ty,
AlignmentSource AlignSource,
llvm::MDNode *TBAAInfo,
bool isInit, QualType TBAABaseType,
uint64_t TBAAOffset,
bool isNontemporal) {
// Handle vectors differently to get better performance.
if (Ty->isVectorType()) {
llvm::Type *SrcTy = Value->getType();
auto *VecTy = cast<llvm::VectorType>(SrcTy);
// Handle vec3 special.
if (VecTy->getNumElements() == 3) {
// Our source is a vec3, do a shuffle vector to make it a vec4.
llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
Builder.getInt32(2),
llvm::UndefValue::get(Builder.getInt32Ty())};
llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
Value = Builder.CreateShuffleVector(Value,
llvm::UndefValue::get(VecTy),
MaskV, "extractVec");
SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
}
if (Addr.getElementType() != SrcTy) {
Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
}
}
Value = EmitToMemory(Value, Ty);
LValue AtomicLValue =
LValue::MakeAddr(Addr, Ty, getContext(), AlignSource, TBAAInfo);
if (Ty->isAtomicType() ||
(!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
return;
}
llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
if (isNontemporal) {
llvm::MDNode *Node =
llvm::MDNode::get(Store->getContext(),
llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
}
if (TBAAInfo) {
llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
TBAAOffset);
if (TBAAPath)
CGM.DecorateInstructionWithTBAA(Store, TBAAPath,
false /*ConvertTypeToTag*/);
}
}
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
bool isInit) {
EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
lvalue.getType(), lvalue.getAlignmentSource(),
lvalue.getTBAAInfo(), isInit, lvalue.getTBAABaseType(),
lvalue.getTBAAOffset(), lvalue.isNontemporal());
}
/// 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, SourceLocation Loc) {
if (LV.isObjCWeak()) {
// load of a __weak object.
Address AddrWeakObj = LV.getAddress();
return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
AddrWeakObj));
}
if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
// In MRC mode, we do a load+autorelease.
if (!getLangOpts().ObjCAutoRefCount) {
return RValue::get(EmitARCLoadWeak(LV.getAddress()));
}
// In ARC mode, we load retained and then consume the value.
llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
Object = EmitObjCConsumeObject(LV.getType(), Object);
return RValue::get(Object);
}
if (LV.isSimple()) {
assert(!LV.getType()->isFunctionType());
// Everything needs a load.
return RValue::get(EmitLoadOfScalar(LV, Loc));
}
if (LV.isVectorElt()) {
llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
LV.isVolatileQualified());
return RValue::get(Builder.CreateExtractElement(Load, 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);
// Global Register variables always invoke intrinsics
if (LV.isGlobalReg())
return EmitLoadOfGlobalRegLValue(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());
Address Ptr = LV.getBitFieldAddress();
llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
if (Info.IsSigned) {
assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
if (HighBits)
Val = Builder.CreateShl(Val, HighBits, "bf.shl");
if (Info.Offset + HighBits)
Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
} else {
if (Info.Offset)
Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
Info.Size),
"bf.clear");
}
Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
return RValue::get(Val);
}
// 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.getExtVectorAddress(),
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(SizeTy, 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)
Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
MaskV);
return RValue::get(Vec);
}
/// @brief Generates lvalue for partial ext_vector access.
Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
Address VectorAddress = LV.getExtVectorAddress();
const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
QualType EQT = ExprVT->getElementType();
llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
Address CastToPointerElement =
Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
"conv.ptr.element");
const llvm::Constant *Elts = LV.getExtVectorElts();
unsigned ix = getAccessedFieldNo(0, Elts);
Address VectorBasePtrPlusIx =
Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
getContext().getTypeSizeInChars(EQT),
"vector.elt");
return VectorBasePtrPlusIx;
}
/// @brief Load of global gamed gegisters are always calls to intrinsics.
RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
"Bad type for register variable");
llvm::MDNode *RegName = cast<llvm::MDNode>(
cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
// We accept integer and pointer types only
llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
llvm::Type *Ty = OrigTy;
if (OrigTy->isPointerTy())
Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
llvm::Type *Types[] = { Ty };
llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
llvm::Value *Call = Builder.CreateCall(
F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
if (OrigTy->isPointerTy())
Call = Builder.CreateIntToPtr(Call, OrigTy);
return RValue::get(Call);
}
/// 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.getVectorAddress(),
Dst.isVolatileQualified());
Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
Dst.getVectorIdx(), "vecins");
Builder.CreateStore(Vec, Dst.getVectorAddress(),
Dst.isVolatileQualified());
return;
}
// If this is an update of extended vector elements, insert them as
// appropriate.
if (Dst.isExtVectorElt())
return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
if (Dst.isGlobalReg())
return EmitStoreThroughGlobalRegLValue(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:
if (isInit) {
Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
break;
}
EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
return;
case Qualifiers::OCL_Weak:
if (isInit)
// Initialize and then skip the primitive store.
EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
else
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.
Address 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.
Address LvalueDst = Dst.getAddress();
llvm::Value *src = Src.getScalarVal();
if (Dst.isObjCIvar()) {
assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
llvm::Type *ResultType = IntPtrTy;
Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
llvm::Value *RHS = dst.getPointer();
RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
llvm::Value *LHS =
Builder.CreatePtrToInt(LvalueDst.getPointer(), 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();
llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
Address Ptr = Dst.getBitFieldAddress();
// Get the source value, truncated to the width of the bit-field.
llvm::Value *SrcVal = Src.getScalarVal();
// Cast the source to the storage type and shift it into place.
SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
/*IsSigned=*/false);
llvm::Value *MaskedVal = SrcVal;
// See if there are other bits in the bitfield's storage we'll need to load
// and mask together with source before storing.
if (Info.StorageSize != Info.Size) {
assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
llvm::Value *Val =
Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
// Mask the source value as needed.
if (!hasBooleanRepresentation(Dst.getType()))
SrcVal = Builder.CreateAnd(SrcVal,
llvm::APInt::getLowBitsSet(Info.StorageSize,
Info.Size),
"bf.value");
MaskedVal = SrcVal;
if (Info.Offset)
SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
// Mask out the original value.
Val = Builder.CreateAnd(Val,
~llvm::APInt::getBitsSet(Info.StorageSize,
Info.Offset,
Info.Offset + Info.Size),
"bf.clear");
// Or together the unchanged values and the source value.
SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
} else {
assert(Info.Offset == 0);
}
// Write the new value back out.
Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
// Return the new value of the bit-field, if requested.
if (Result) {
llvm::Value *ResultVal = MaskedVal;
// Sign extend the value if needed.
if (Info.IsSigned) {
assert(Info.Size <= Info.StorageSize);
unsigned HighBits = Info.StorageSize - Info.Size;
if (HighBits) {
ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
}
}
ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
"bf.result.cast");
*Result = EmitFromMemory(ResultVal, Dst.getType());
}
}
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.getExtVectorAddress(),
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 = Vec->getType()->getVectorNumElements();
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)
Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(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;
for (unsigned i = 0; i != NumSrcElts; ++i)
ExtMask.push_back(Builder.getInt32(i));
ExtMask.resize(NumDstElts, 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(Builder.getInt32(i));
// When the vector size is odd and .odd or .hi is used, the last element
// of the Elts constant array will be one past the size of the vector.
// Ignore the last element here, if it is greater than the mask size.
if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
NumSrcElts--;
// modify when what gets shuffled in
for (unsigned i = 0; i != NumSrcElts; ++i)
Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(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(SizeTy, InIdx);
Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
}
Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
Dst.isVolatileQualified());
}
/// @brief Store of global named registers are always calls to intrinsics.
void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
"Bad type for register variable");
llvm::MDNode *RegName = cast<llvm::MDNode>(
cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
assert(RegName && "Register LValue is not metadata");
// We accept integer and pointer types only
llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
llvm::Type *Ty = OrigTy;
if (OrigTy->isPointerTy())
Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
llvm::Type *Types[] = { Ty };
llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
llvm::Value *Value = Src.getScalarVal();
if (OrigTy->isPointerTy())
Value = Builder.CreatePtrToInt(Value, Ty);
Builder.CreateCall(
F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
}
// setObjCGCLValueClass - sets class of the 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.getLangOpts().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);
auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
LV.setBaseIvarExp(Exp->getBase());
LV.setObjCArray(E->getType()->isArrayType());
return;
}
if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
if (VD->hasGlobalStorage()) {
LV.setGlobalObjCRef(true);
LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
}
}
LV.setObjCArray(E->getType()->isArrayType());
return;
}
if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const auto *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 auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
return;
}
if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
return;
}
if (const auto *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 auto *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 EmitThreadPrivateVarDeclLValue(
CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
llvm::Type *RealVarTy, SourceLocation Loc) {
Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
}
Address CodeGenFunction::EmitLoadOfReference(Address Addr,
const ReferenceType *RefTy,
AlignmentSource *Source) {
llvm::Value *Ptr = Builder.CreateLoad(Addr);
return Address(Ptr, getNaturalTypeAlignment(RefTy->getPointeeType(),
Source, /*forPointee*/ true));
}
LValue CodeGenFunction::EmitLoadOfReferenceLValue(Address RefAddr,
const ReferenceType *RefTy) {
AlignmentSource Source;
Address Addr = EmitLoadOfReference(RefAddr, RefTy, &Source);
return MakeAddrLValue(Addr, RefTy->getPointeeType(), Source);
}
Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
const PointerType *PtrTy,
AlignmentSource *Source) {
llvm::Value *Addr = Builder.CreateLoad(Ptr);
return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(), Source,
/*forPointeeType=*/true));
}
LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
const PointerType *PtrTy) {
AlignmentSource Source;
Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &Source);
return MakeAddrLValue(Addr, PtrTy->getPointeeType(), Source);
}
static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
const Expr *E, const VarDecl *VD) {
QualType T = E->getType();
// If it's thread_local, emit a call to its wrapper function instead.
if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
CGF.CGM.getCXXABI().usesThreadWrapperFunction())
return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
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);
Address Addr(V, Alignment);
LValue LV;
// Emit reference to the private copy of the variable if it is an OpenMP
// threadprivate variable.
if (CGF.getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>())
return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
E->getExprLoc());
if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
LV = CGF.EmitLoadOfReferenceLValue(Addr, RefTy);
} else {
LV = CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
}
setObjCGCLValueClass(CGF.getContext(), E, LV);
return LV;
}
static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
const FunctionDecl *FD) {
if (FD->hasAttr<WeakRefAttr>()) {
ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
return aliasee.getPointer();
}
llvm::Constant *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 =
CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
NoProtoType = CGM.getContext().getPointerType(NoProtoType);
V = llvm::ConstantExpr::getBitCast(V,
CGM.getTypes().ConvertType(NoProtoType));
}
}
return V;
}
static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
const Expr *E, const FunctionDecl *FD) {
llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
return CGF.MakeAddrLValue(V, E->getType(), Alignment, AlignmentSource::Decl);
}
static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
llvm::Value *ThisValue) {
QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
return CGF.EmitLValueForField(LV, FD);
}
/// Named Registers are named metadata pointing to the register name
/// which will be read from/written to as an argument to the intrinsic
/// @llvm.read/write_register.
/// So far, only the name is being passed down, but other options such as
/// register type, allocation type or even optimization options could be
/// passed down via the metadata node.
static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
SmallString<64> Name("llvm.named.register.");
AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
assert(Asm->getLabel().size() < 64-Name.size() &&
"Register name too big");
Name.append(Asm->getLabel());
llvm::NamedMDNode *M =
CGM.getModule().getOrInsertNamedMetadata(Name);
if (M->getNumOperands() == 0) {
llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
Asm->getLabel());
llvm::Metadata *Ops[] = {Str};
M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
}
CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
llvm::Value *Ptr =
llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
}
LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
const NamedDecl *ND = E->getDecl();
QualType T = E->getType();
if (const auto *VD = dyn_cast<VarDecl>(ND)) {
// Global Named registers access via intrinsics only
if (VD->getStorageClass() == SC_Register &&
VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
return EmitGlobalNamedRegister(VD, CGM);
// A DeclRefExpr for a reference initialized by a constant expression can
// appear without being odr-used. Directly emit the constant initializer.
const Expr *Init = VD->getAnyInitializer(VD);
if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
VD->isUsableInConstantExpressions(getContext()) &&
VD->checkInitIsICE() &&
// Do not emit if it is private OpenMP variable.
!(E->refersToEnclosingVariableOrCapture() && CapturedStmtInfo &&
LocalDeclMap.count(VD))) {
llvm::Constant *Val =
CGM.EmitConstantValue(*VD->evaluateValue(), VD->getType(), this);
assert(Val && "failed to emit reference constant expression");
// FIXME: Eventually we will want to emit vector element references.
// Should we be using the alignment of the constant pointer we emitted?
CharUnits Alignment = getNaturalTypeAlignment(E->getType(), nullptr,
/*pointee*/ true);
return MakeAddrLValue(Address(Val, Alignment), T, AlignmentSource::Decl);
}
// Check for captured variables.
if (E->refersToEnclosingVariableOrCapture()) {
if (auto *FD = LambdaCaptureFields.lookup(VD))
return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
else if (CapturedStmtInfo) {
auto I = LocalDeclMap.find(VD);
if (I != LocalDeclMap.end()) {
if (auto RefTy = VD->getType()->getAs<ReferenceType>())
return EmitLoadOfReferenceLValue(I->second, RefTy);
return MakeAddrLValue(I->second, T);
}
LValue CapLVal =
EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
CapturedStmtInfo->getContextValue());
return MakeAddrLValue(
Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
CapLVal.getType(), AlignmentSource::Decl);
}
assert(isa<BlockDecl>(CurCodeDecl));
Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
return MakeAddrLValue(addr, T, AlignmentSource::Decl);
}
}
// 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 auto *VD = cast<ValueDecl>(ND);
ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
}
if (const auto *VD = dyn_cast<VarDecl>(ND)) {
// Check if this is a global variable.
if (VD->hasLinkage() || VD->isStaticDataMember())
return EmitGlobalVarDeclLValue(*this, E, VD);
Address addr = Address::invalid();
// The variable should generally be present in the local decl map.
auto iter = LocalDeclMap.find(VD);
if (iter != LocalDeclMap.end()) {
addr = iter->second;
// Otherwise, it might be static local we haven't emitted yet for
// some reason; most likely, because it's in an outer function.
} else if (VD->isStaticLocal()) {
addr = Address(CGM.getOrCreateStaticVarDecl(
*VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
getContext().getDeclAlign(VD));
// No other cases for now.
} else {
llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
}
// Check for OpenMP threadprivate variables.
if (getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
return EmitThreadPrivateVarDeclLValue(
*this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
E->getExprLoc());
}
// Drill into block byref variables.
bool isBlockByref = VD->hasAttr<BlocksAttr>();
if (isBlockByref) {
addr = emitBlockByrefAddress(addr, VD);
}
// Drill into reference types.
LValue LV;
if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
LV = EmitLoadOfReferenceLValue(addr, RefTy);
} else {
LV = MakeAddrLValue(addr, T, AlignmentSource::Decl);
}
bool isLocalStorage = VD->hasLocalStorage();
bool NonGCable = isLocalStorage &&
!VD->getType()->isReferenceType() &&
!isBlockByref;
if (NonGCable) {
LV.getQuals().removeObjCGCAttr();
LV.setNonGC(true);
}
bool isImpreciseLifetime =
(isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
if (isImpreciseLifetime)
LV.setARCPreciseLifetime(ARCImpreciseLifetime);
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
if (const auto *FD = dyn_cast<FunctionDecl>(ND))
return EmitFunctionDeclLValue(*this, E, FD);
// FIXME: While we're emitting a binding from an enclosing scope, all other
// DeclRefExprs we see should be implicitly treated as if they also refer to
// an enclosing scope.
if (const auto *BD = dyn_cast<BindingDecl>(ND))
return EmitLValue(BD->getBinding());
llvm_unreachable("Unhandled DeclRefExpr");
}
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");
AlignmentSource AlignSource;
Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &AlignSource);
LValue LV = MakeAddrLValue(Addr, T, AlignSource);
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 (getLangOpts().ObjC1 &&
getLangOpts().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");
// __real is valid on scalars. This is a faster way of testing that.
// __imag can only produce an rvalue on scalars.
if (E->getOpcode() == UO_Real &&
!LV.getAddress().getElementType()->isStructTy()) {
assert(E->getSubExpr()->getType()->isArithmeticType());
return LV;
}
QualType T = ExprTy->castAs<ComplexType>()->getElementType();
Address Component =
(E->getOpcode() == UO_Real
? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
: emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
LValue ElemLV = MakeAddrLValue(Component, T, LV.getAlignmentSource());
ElemLV.getQuals().addQualifiers(LV.getQuals());
return ElemLV;
}
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(), AlignmentSource::Decl);
}
LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
E->getType(), AlignmentSource::Decl);
}
LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
auto SL = E->getFunctionName();
assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
StringRef FnName = CurFn->getName();
if (FnName.startswith("\01"))
FnName = FnName.substr(1);
StringRef NameItems[] = {
PredefinedExpr::getIdentTypeName(E->getIdentType()), FnName};
std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
if (auto *BD = dyn_cast<BlockDecl>(CurCodeDecl)) {
std::string Name = SL->getString();
if (!Name.empty()) {
unsigned Discriminator =
CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
if (Discriminator)
Name += "_" + Twine(Discriminator + 1).str();
auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
} else {
auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
return MakeAddrLValue(C, E->getType(),