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llvm-project/clang/lib/CodeGen/CGExpr.cpp
Saleem Abdulrasool 05b8fde8ee CodeGen: ubsan is built static on windows, give handlers local storage 
The UBSAN runtime is built static on Windows.  This requires that we give local
storage always.  This impacts Windows where the linker would otherwise have to
generate a thunk to access the symbol via the IAT.  This should repair the
windows clang build bots.

llvm-svn: 289829
2016-12-15 16:30:20 +00:00

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170 KiB
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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) {
llvm::Constant *StaticData[] = {
EmitCheckSourceLocation(Loc),
EmitCheckTypeDescriptor(Ty),
llvm::ConstantInt::get(SizeTy, AlignVal),
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(), AlignmentSource::Decl);
}
}
auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
}
/// Emit a type description suitable for use by a runtime sanitizer library. The
/// format of a type descriptor is
///
/// \code
/// { i16 TypeKind, i16 TypeInfo }
/// \endcode
///
/// followed by an array of i8 containing the type name. TypeKind is 0 for an
/// integer, 1 for a floating point value, and -1 for anything else.
llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
// Only emit each type's descriptor once.
if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
return C;
uint16_t TypeKind = -1;
uint16_t TypeInfo = 0;
if (T->isIntegerType()) {
TypeKind = 0;
TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
(T->isSignedIntegerType() ? 1 : 0);
} else if (T->isFloatingType()) {
TypeKind = 1;
TypeInfo = getContext().getTypeSize(T);
}
// Format the type name as if for a diagnostic, including quotes and
// optionally an 'aka'.
SmallString<32> Buffer;
CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
(intptr_t)T.getAsOpaquePtr(),
StringRef(), StringRef(), None, Buffer,
None);
llvm::Constant *Components[] = {
Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
};
llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
auto *GV = new llvm::GlobalVariable(
CGM.getModule(), Descriptor->getType(),
/*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
// Remember the descriptor for this type.
CGM.setTypeDescriptorInMap(T, GV);
return GV;
}
llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
llvm::Type *TargetTy = IntPtrTy;
// Floating-point types which fit into intptr_t are bitcast to integers
// and then passed directly (after zero-extension, if necessary).
if (V->getType()->isFloatingPointTy()) {
unsigned Bits = V->getType()->getPrimitiveSizeInBits();
if (Bits <= TargetTy->getIntegerBitWidth())
V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
Bits));
}
// Integers which fit in intptr_t are zero-extended and passed directly.
if (V->getType()->isIntegerTy() &&
V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
return Builder.CreateZExt(V, TargetTy);
// Pointers are passed directly, everything else is passed by address.
if (!V->getType()->isPointerTy()) {
Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
Builder.CreateStore(V, Ptr);
V = Ptr.getPointer();
}
return Builder.CreatePtrToInt(V, TargetTy);
}
/// \brief Emit a representation of a SourceLocation for passing to a handler
/// in a sanitizer runtime library. The format for this data is:
/// \code
/// struct SourceLocation {
/// const char *Filename;
/// int32_t Line, Column;
/// };
/// \endcode
/// For an invalid SourceLocation, the Filename pointer is null.
llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
llvm::Constant *Filename;
int Line, Column;
PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
if (PLoc.isValid()) {
StringRef FilenameString = PLoc.getFilename();
int PathComponentsToStrip =
CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
if (PathComponentsToStrip < 0) {
assert(PathComponentsToStrip != INT_MIN);
int PathComponentsToKeep = -PathComponentsToStrip;
auto I = llvm::sys::path::rbegin(FilenameString);
auto E = llvm::sys::path::rend(FilenameString);
while (I != E && --PathComponentsToKeep)
++I;
FilenameString = FilenameString.substr(I - E);
} else if (PathComponentsToStrip > 0) {
auto I = llvm::sys::path::begin(FilenameString);
auto E = llvm::sys::path::end(FilenameString);
while (I != E && PathComponentsToStrip--)
++I;
if (I != E)
FilenameString =
FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
else
FilenameString = llvm::sys::path::filename(FilenameString);
}
auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
Filename = FilenameGV.getPointer();
Line = PLoc.getLine();
Column = PLoc.getColumn();
} else {
Filename = llvm::Constant::getNullValue(Int8PtrTy);
Line = Column = 0;
}
llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
Builder.getInt32(Column)};
return llvm::ConstantStruct::getAnon(Data);
}
namespace {
/// \brief Specify under what conditions this check can be recovered
enum class CheckRecoverableKind {
/// Always terminate program execution if this check fails.
Unrecoverable,
/// Check supports recovering, runtime has both fatal (noreturn) and
/// non-fatal handlers for this check.
Recoverable,
/// Runtime conditionally aborts, always need to support recovery.
AlwaysRecoverable
};
}
static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
assert(llvm::countPopulation(Kind) == 1);
switch (Kind) {
case SanitizerKind::Vptr:
return CheckRecoverableKind::AlwaysRecoverable;
case SanitizerKind::Return:
case SanitizerKind::Unreachable:
return CheckRecoverableKind::Unrecoverable;
default:
return CheckRecoverableKind::Recoverable;
}
}
namespace {
struct SanitizerHandlerInfo {
char const *const Name;
unsigned Version;
};
}
const SanitizerHandlerInfo SanitizerHandlers[] = {
#define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
LIST_SANITIZER_CHECKS
#undef SANITIZER_CHECK
};
static void emitCheckHandlerCall(CodeGenFunction &CGF,
llvm::FunctionType *FnType,
ArrayRef<llvm::Value *> FnArgs,
SanitizerHandler CheckHandler,
CheckRecoverableKind RecoverKind, bool IsFatal,
llvm::BasicBlock *ContBB) {
assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
bool NeedsAbortSuffix =
IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
const StringRef CheckName = CheckInfo.Name;
std::string FnName =
("__ubsan_handle_" + CheckName +
(CheckInfo.Version ? "_v" + llvm::utostr(CheckInfo.Version) : "") +
(NeedsAbortSuffix ? "_abort" : ""))
.str();
bool MayReturn =
!IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
llvm::AttrBuilder B;
if (!MayReturn) {
B.addAttribute(llvm::Attribute::NoReturn)
.addAttribute(llvm::Attribute::NoUnwind);
}
B.addAttribute(llvm::Attribute::UWTable);
llvm::Value *Fn = CGF.CGM.CreateRuntimeFunction(
FnType, FnName,
llvm::AttributeSet::get(CGF.getLLVMContext(),
llvm::AttributeSet::FunctionIndex, B),
/*Local=*/true);
llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
if (!MayReturn) {
HandlerCall->setDoesNotReturn();
CGF.Builder.CreateUnreachable();
} else {
CGF.Builder.CreateBr(ContBB);
}
}
void CodeGenFunction::EmitCheck(
ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
ArrayRef<llvm::Value *> DynamicArgs) {
assert(IsSanitizerScope);
assert(Checked.size() > 0);
assert(CheckHandler >= 0 &&
CheckHandler < sizeof(SanitizerHandlers) / sizeof(*SanitizerHandlers));
const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
llvm::Value *FatalCond = nullptr;
llvm::Value *RecoverableCond = nullptr;
llvm::Value *TrapCond = nullptr;
for (int i = 0, n = Checked.size(); i < n; ++i) {
llvm::Value *Check = Checked[i].first;
// -fsanitize-trap= overrides -fsanitize-recover=.
llvm::Value *&Cond =
CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
? TrapCond
: CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
? RecoverableCond
: FatalCond;
Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
}
if (TrapCond)
EmitTrapCheck(TrapCond);
if (!FatalCond && !RecoverableCond)
return;
llvm::Value *JointCond;
if (FatalCond && RecoverableCond)
JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
else
JointCond = FatalCond ? FatalCond : RecoverableCond;
assert(JointCond);
CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
assert(SanOpts.has(Checked[0].second));
#ifndef NDEBUG
for (int i = 1, n = Checked.size(); i < n; ++i) {
assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
"All recoverable kinds in a single check must be same!");
assert(SanOpts.has(Checked[i].second));
}
#endif
llvm::BasicBlock *Cont = createBasicBlock("cont");
llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
// Give hint that we very much don't expect to execute the handler
// Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
llvm::MDBuilder MDHelper(getLLVMContext());
llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
EmitBlock(Handlers);
// Handler functions take an i8* pointing to the (handler-specific) static
// information block, followed by a sequence of intptr_t arguments
// representing operand values.
SmallVector<llvm::Value *, 4> Args;
SmallVector<llvm::Type *, 4> ArgTypes;
Args.reserve(DynamicArgs.size() + 1);
ArgTypes.reserve(DynamicArgs.size() + 1);
// Emit handler arguments and create handler function type.
if (!StaticArgs.empty()) {
llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
auto *InfoPtr =
new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
llvm::GlobalVariable::PrivateLinkage, Info);
InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
ArgTypes.push_back(Int8PtrTy);
}
for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
Args.push_back(EmitCheckValue(DynamicArgs[i]));
ArgTypes.push_back(IntPtrTy);
}
llvm::FunctionType *FnType =
llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
if (!FatalCond || !RecoverableCond) {
// Simple case: we need to generate a single handler call, either
// fatal, or non-fatal.
emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
(FatalCond != nullptr), Cont);
} else {
// Emit two handler calls: first one for set of unrecoverable checks,
// another one for recoverable.
llvm::BasicBlock *NonFatalHandlerBB =
createBasicBlock("non_fatal." + CheckName);
llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
EmitBlock(FatalHandlerBB);
emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
NonFatalHandlerBB);
EmitBlock(NonFatalHandlerBB);
emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
Cont);
}
EmitBlock(Cont);
}
void CodeGenFunction::EmitCfiSlowPathCheck(
SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
llvm::MDBuilder MDHelper(getLLVMContext());
llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
EmitBlock(CheckBB);
bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
llvm::CallInst *CheckCall;
if (WithDiag) {
llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
auto *InfoPtr =
new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
llvm::GlobalVariable::PrivateLinkage, Info);
InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
llvm::Constant *SlowPathDiagFn = CGM.getModule().getOrInsertFunction(
"__cfi_slowpath_diag",
llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
false));
CheckCall = Builder.CreateCall(
SlowPathDiagFn,
{TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
} else {
llvm::Constant *SlowPathFn = CGM.getModule().getOrInsertFunction(
"__cfi_slowpath",
llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
}
CheckCall->setDoesNotThrow();
EmitBlock(Cont);
}
// This function is basically a switch over the CFI failure kind, which is
// extracted from CFICheckFailData (1st function argument). Each case is either
// llvm.trap or a call to one of the two runtime handlers, based on
// -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
// failure kind) traps, but this should really never happen. CFICheckFailData
// can be nullptr if the calling module has -fsanitize-trap behavior for this
// check kind; in this case __cfi_check_fail traps as well.
void CodeGenFunction::EmitCfiCheckFail() {
SanitizerScope SanScope(this);
FunctionArgList Args;
ImplicitParamDecl ArgData(getContext(), nullptr, SourceLocation(), nullptr,
getContext().VoidPtrTy);
ImplicitParamDecl ArgAddr(getContext(), nullptr, SourceLocation(), nullptr,
getContext().VoidPtrTy);
Args.push_back(&ArgData);
Args.push_back(&ArgAddr);
const CGFunctionInfo &FI =
CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
llvm::Function *F = llvm::Function::Create(
llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
F->setVisibility(llvm::GlobalValue::HiddenVisibility);
StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
SourceLocation());
llvm::Value *Data =
EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
CGM.getContext().VoidPtrTy, ArgData.getLocation());
llvm::Value *Addr =
EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
// Data == nullptr means the calling module has trap behaviour for this check.
llvm::Value *DataIsNotNullPtr =
Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
EmitTrapCheck(DataIsNotNullPtr);
llvm::StructType *SourceLocationTy =
llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty, nullptr);
llvm::StructType *CfiCheckFailDataTy =
llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy, nullptr);
llvm::Value *V = Builder.CreateConstGEP2_32(
CfiCheckFailDataTy,
Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
0);
Address CheckKindAddr(V, getIntAlign());
llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
llvm::Value *AllVtables = llvm::MetadataAsValue::get(
CGM.getLLVMContext(),
llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
llvm::Value *ValidVtable = Builder.CreateZExt(
Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
{Addr, AllVtables}),
IntPtrTy);
const std::pair<int, SanitizerMask> CheckKinds[] = {
{CFITCK_VCall, SanitizerKind::CFIVCall},
{CFITCK_NVCall, SanitizerKind::CFINVCall},
{CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
{CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
{CFITCK_ICall, SanitizerKind::CFIICall}};
SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
for (auto CheckKindMaskPair : CheckKinds) {
int Kind = CheckKindMaskPair.first;
SanitizerMask Mask = CheckKindMaskPair.second;
llvm::Value *Cond =
Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
if (CGM.getLangOpts().Sanitize.has(Mask))
EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
{Data, Addr, ValidVtable});
else
EmitTrapCheck(Cond);
}
FinishFunction();
// The only reference to this function will be created during LTO link.
// Make sure it survives until then.
CGM.addUsedGlobal(F);
}
void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
llvm::BasicBlock *Cont = createBasicBlock("cont");
// If we're optimizing, collapse all calls to trap down to just one per
// function to save on code size.
if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
TrapBB = createBasicBlock("trap");
Builder.CreateCondBr(Checked, Cont, TrapBB);
EmitBlock(TrapBB);
llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
TrapCall->setDoesNotReturn();
TrapCall->setDoesNotThrow();
Builder.CreateUnreachable();
} else {
Builder.CreateCondBr(Checked, Cont, TrapBB);
}
EmitBlock(Cont);
}
llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
CGM.getCodeGenOpts().TrapFuncName);
TrapCall->addAttribute(llvm::AttributeSet::FunctionIndex, A);
}
return TrapCall;
}
Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
AlignmentSource *AlignSource) {
assert(E->getType()->isArrayType() &&
"Array to pointer decay must have array source type!");
// Expressions of array type can't be bitfields or vector elements.
LValue LV = EmitLValue(E);
Address Addr = LV.getAddress();
if (AlignSource) *AlignSource = LV.getAlignmentSource();
// If the array type was an incomplete type, we need to make sure
// the decay ends up being the right type.
llvm::Type *NewTy = ConvertType(E->getType());
Addr = Builder.CreateElementBitCast(Addr, NewTy);
// Note that VLA pointers are always decayed, so we don't need to do
// anything here.
if (!E->getType()->isVariableArrayType()) {
assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
"Expected pointer to array");
Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
}
QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
}
/// 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 auto *CE = dyn_cast<CastExpr>(E);
if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
return nullptr;
// If this is a decay from variable width array, bail out.
const Expr *SubExpr = CE->getSubExpr();
if (SubExpr->getType()->isVariableArrayType())
return nullptr;
return SubExpr;
}
static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
llvm::Value *ptr,
ArrayRef<llvm::Value*> indices,
bool inbounds,
const llvm::Twine &name = "arrayidx") {
if (inbounds) {
return CGF.Builder.CreateInBoundsGEP(ptr, indices, name);
} else {
return CGF.Builder.CreateGEP(ptr, indices, name);
}
}
static CharUnits getArrayElementAlign(CharUnits arrayAlign,
llvm::Value *idx,
CharUnits eltSize) {
// If we have a constant index, we can use the exact offset of the
// element we're accessing.
if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
CharUnits offset = constantIdx->getZExtValue() * eltSize;
return arrayAlign.alignmentAtOffset(offset);
// Otherwise, use the worst-case alignment for any element.
} else {
return arrayAlign.alignmentOfArrayElement(eltSize);
}
}
static QualType getFixedSizeElementType(const ASTContext &ctx,
const VariableArrayType *vla) {
QualType eltType;
do {
eltType = vla->getElementType();
} while ((vla = ctx.getAsVariableArrayType(eltType)));
return eltType;
}
static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
ArrayRef<llvm::Value*> indices,
QualType eltType, bool inbounds,
const llvm::Twine &name = "arrayidx") {
// All the indices except that last must be zero.
#ifndef NDEBUG
for (auto idx : indices.drop_back())
assert(isa<llvm::ConstantInt>(idx) &&
cast<llvm::ConstantInt>(idx)->isZero());
#endif
// Determine the element size of the statically-sized base. This is
// the thing that the indices are expressed in terms of.
if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
eltType = getFixedSizeElementType(CGF.getContext(), vla);
}
// We can use that to compute the best alignment of the element.
CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
CharUnits eltAlign =
getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
llvm::Value *eltPtr =
emitArraySubscriptGEP(CGF, addr.getPointer(), indices, inbounds, name);
return Address(eltPtr, eltAlign);
}
LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
bool Accessed) {
// The index must always be an integer, which is not an aggregate. Emit it
// in lexical order (this complexity is, sadly, required by C++17).
llvm::Value *IdxPre =
(E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
auto *Idx = IdxPre;
if (E->getLHS() != E->getIdx()) {
assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
Idx = EmitScalarExpr(E->getIdx());
}
QualType IdxTy = E->getIdx()->getType();
bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
if (SanOpts.has(SanitizerKind::ArrayBounds))
EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
// Extend or truncate the index type to 32 or 64-bits.
if (Promote && Idx->getType() != IntPtrTy)
Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
return Idx;
};
IdxPre = nullptr;
// If the base is a vector type, then we are forming a vector element lvalue
// with this subscript.
if (E->getBase()->getType()->isVectorType() &&
!isa<ExtVectorElementExpr>(E->getBase())) {
// Emit the vector as an lvalue to get its address.
LValue LHS = EmitLValue(E->getBase());
auto *Idx = EmitIdxAfterBase(/*Promote*/false);
assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
return LValue::MakeVectorElt(LHS.getAddress(), Idx,
E->getBase()->getType(),
LHS.getAlignmentSource());
}
// All the other cases basically behave like simple offsetting.
// Handle the extvector case we ignored above.
if (isa<ExtVectorElementExpr>(E->getBase())) {
LValue LV = EmitLValue(E->getBase());
auto *Idx = EmitIdxAfterBase(/*Promote*/true);
Address Addr = EmitExtVectorElementLValue(LV);
QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true);
return MakeAddrLValue(Addr, EltType, LV.getAlignmentSource());
}
AlignmentSource AlignSource;
Address Addr = Address::invalid();
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.
Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
auto *Idx = EmitIdxAfterBase(/*Promote*/true);
// 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 (getLangOpts().isSignedOverflowDefined()) {
Idx = Builder.CreateMul(Idx, numElements);
} else {
Idx = Builder.CreateNSWMul(Idx, numElements);
}
Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
!getLangOpts().isSignedOverflowDefined());
} else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
// Indexing over an interface, as in "NSString *P; P[4];"
// Emit the base pointer.
Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
auto *Idx = EmitIdxAfterBase(/*Promote*/true);
CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
llvm::Value *InterfaceSizeVal =
llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
// We don't necessarily build correct LLVM struct types for ObjC
// interfaces, so we can't rely on GEP to do this scaling
// correctly, so we need to cast to i8*. FIXME: is this actually
// true? A lot of other things in the fragile ABI would break...
llvm::Type *OrigBaseTy = Addr.getType();
Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
// Do the GEP.
CharUnits EltAlign =
getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
llvm::Value *EltPtr =
emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false);
Addr = Address(EltPtr, EltAlign);
// Cast back.
Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
} 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;
// For simple multidimensional array indexing, set the 'accessed' flag for
// better bounds-checking of the base expression.
if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
else
ArrayLV = EmitLValue(Array);
auto *Idx = EmitIdxAfterBase(/*Promote*/true);
// Propagate the alignment from the array itself to the result.
Addr = emitArraySubscriptGEP(*this, ArrayLV.getAddress(),
{CGM.getSize(CharUnits::Zero()), Idx},
E->getType(),
!getLangOpts().isSignedOverflowDefined());
AlignSource = ArrayLV.getAlignmentSource();
} else {
// The base must be a pointer; emit it with an estimate of its alignment.
Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
auto *Idx = EmitIdxAfterBase(/*Promote*/true);
Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
!getLangOpts().isSignedOverflowDefined());
}
LValue LV = MakeAddrLValue(Addr, E->getType(), AlignSource);
// TODO: Preserve/extend path TBAA metadata?
if (getLangOpts().ObjC1 &&
getLangOpts().getGC() != LangOptions::NonGC) {
LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
setObjCGCLValueClass(getContext(), E, LV);
}
return LV;
}
static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
AlignmentSource &AlignSource,
QualType BaseTy, QualType ElTy,
bool IsLowerBound) {
LValue BaseLVal;
if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
if (BaseTy->isArrayType()) {
Address Addr = BaseLVal.getAddress();
AlignSource = BaseLVal.getAlignmentSource();
// If the array type was an incomplete type, we need to make sure
// the decay ends up being the right type.
llvm::Type *NewTy = CGF.ConvertType(BaseTy);
Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
// Note that VLA pointers are always decayed, so we don't need to do
// anything here.
if (!BaseTy->isVariableArrayType()) {
assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
"Expected pointer to array");
Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
"arraydecay");
}
return CGF.Builder.CreateElementBitCast(Addr,
CGF.ConvertTypeForMem(ElTy));
}
CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &AlignSource);
return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
}
return CGF.EmitPointerWithAlignment(Base, &AlignSource);
}
LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
bool IsLowerBound) {
QualType BaseTy;
if (auto *ASE =
dyn_cast<OMPArraySectionExpr>(E->getBase()->IgnoreParenImpCasts()))
BaseTy = OMPArraySectionExpr::getBaseOriginalType(ASE);
else
BaseTy = E->getBase()->getType();
QualType ResultExprTy;
if (auto *AT = getContext().getAsArrayType(BaseTy))
ResultExprTy = AT->getElementType();
else
ResultExprTy = BaseTy->getPointeeType();
llvm::Value *Idx = nullptr;
if (IsLowerBound || E->getColonLoc().isInvalid()) {
// Requesting lower bound or upper bound, but without provided length and
// without ':' symbol for the default length -> length = 1.
// Idx = LowerBound ?: 0;
if (auto *LowerBound = E->getLowerBound()) {
Idx = Builder.CreateIntCast(
EmitScalarExpr(LowerBound), IntPtrTy,
LowerBound->getType()->hasSignedIntegerRepresentation());
} else
Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
} else {
// Try to emit length or lower bound as constant. If this is possible, 1
// is subtracted from constant length or lower bound. Otherwise, emit LLVM
// IR (LB + Len) - 1.
auto &C = CGM.getContext();
auto *Length = E->getLength();
llvm::APSInt ConstLength;
if (Length) {
// Idx = LowerBound + Length - 1;
if (Length->isIntegerConstantExpr(ConstLength, C)) {
ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
Length = nullptr;
}
auto *LowerBound = E->getLowerBound();
llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
LowerBound = nullptr;
}
if (!Length)
--ConstLength;
else if (!LowerBound)
--ConstLowerBound;
if (Length || LowerBound) {
auto *LowerBoundVal =
LowerBound
? Builder.CreateIntCast(
EmitScalarExpr(LowerBound), IntPtrTy,
LowerBound->getType()->hasSignedIntegerRepresentation())
: llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
auto *LengthVal =
Length
? Builder.CreateIntCast(
EmitScalarExpr(Length), IntPtrTy,
Length->getType()->hasSignedIntegerRepresentation())
: llvm::ConstantInt::get(IntPtrTy, ConstLength);
Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
/*HasNUW=*/false,
!getLangOpts().isSignedOverflowDefined());
if (Length && LowerBound) {
Idx = Builder.CreateSub(
Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
/*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
}
} else
Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
} else {
// Idx = ArraySize - 1;
QualType ArrayTy = BaseTy->isPointerType()
? E->getBase()->IgnoreParenImpCasts()->getType()
: BaseTy;
if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
Length = VAT->getSizeExpr();
if (Length->isIntegerConstantExpr(ConstLength, C))
Length = nullptr;
} else {
auto *CAT = C.getAsConstantArrayType(ArrayTy);
ConstLength = CAT->getSize();
}
if (Length) {
auto *LengthVal = Builder.CreateIntCast(
EmitScalarExpr(Length), IntPtrTy,
Length->getType()->hasSignedIntegerRepresentation());
Idx = Builder.CreateSub(
LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
/*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
} else {
ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
--ConstLength;
Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
}
}
}
assert(Idx);
Address EltPtr = Address::invalid();
AlignmentSource AlignSource;
if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
// 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 Base =
emitOMPArraySectionBase(*this, E->getBase(), AlignSource, BaseTy,
VLA->getElementType(), IsLowerBound);
// 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 (getLangOpts().isSignedOverflowDefined())
Idx = Builder.CreateMul(Idx, NumElements);
else
Idx = Builder.CreateNSWMul(Idx, NumElements);
EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
!getLangOpts().isSignedOverflowDefined());
} 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;
// For simple multidimensional array indexing, set the 'accessed' flag for
// better bounds-checking of the base expression.
if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
else
ArrayLV = EmitLValue(Array);
// Propagate the alignment from the array itself to the result.
EltPtr = emitArraySubscriptGEP(
*this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
ResultExprTy, !getLangOpts().isSignedOverflowDefined());
AlignSource = ArrayLV.getAlignmentSource();
} else {
Address Base = emitOMPArraySectionBase(*this, E->getBase(), AlignSource,
BaseTy, ResultExprTy, IsLowerBound);
EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
!getLangOpts().isSignedOverflowDefined());
}
return MakeAddrLValue(EltPtr, ResultExprTy, AlignSource);
}
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.
AlignmentSource AlignSource;
Address Ptr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
Base = MakeAddrLValue(Ptr, PT->getPointeeType(), AlignSource);
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).
Address VecMem = CreateMemTemp(E->getBase()->getType());
Builder.CreateStore(Vec, VecMem);
Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
AlignmentSource::Decl);
}
QualType type =
E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
// Encode the element access list into a vector of unsigned indices.
SmallVector<uint32_t, 4> Indices;
E->getEncodedElementAccess(Indices);
if (Base.isSimple()) {
llvm::Constant *CV =
llvm::ConstantDataVector::get(getLLVMContext(), Indices);
return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
Base.getAlignmentSource());
}
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)
CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
llvm::Constant *CV = llvm::ConstantVector::get(CElts);
return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
Base.getAlignmentSource());
}
LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
Expr *BaseExpr = E->getBase();
// If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
LValue BaseLV;
if (E->isArrow()) {
AlignmentSource AlignSource;
Address Addr = EmitPointerWithAlignment(BaseExpr, &AlignSource);
QualType PtrTy = BaseExpr->getType()->getPointeeType();
EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy);
BaseLV = MakeAddrLValue(Addr, PtrTy, AlignSource);
} else
BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
NamedDecl *ND = E->getMemberDecl();
if (auto *Field = dyn_cast<FieldDecl>(ND)) {
LValue LV = EmitLValueForField(BaseLV, Field);
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
if (auto *VD = dyn_cast<VarDecl>(ND))
return EmitGlobalVarDeclLValue(*this, E, VD);
if (const auto *FD = dyn_cast<FunctionDecl>(ND))
return EmitFunctionDeclLValue(*this, E, FD);
llvm_unreachable("Unhandled member declaration!");
}
/// Given that we are currently emitting a lambda, emit an l-value for
/// one of its members.
LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
QualType LambdaTagType =
getContext().getTagDeclType(Field->getParent());
LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
return EmitLValueForField(LambdaLV, Field);
}
/// Drill down to the storage of a field without walking into
/// reference types.
///
/// The resulting address doesn't necessarily have the right type.
static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
const FieldDecl *field) {
const RecordDecl *rec = field->getParent();
unsigned idx =
CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
CharUnits offset;
// Adjust the alignment down to the given offset.
// As a special case, if the LLVM field index is 0, we know that this
// is zero.
assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
.getFieldOffset(field->getFieldIndex()) == 0) &&
"LLVM field at index zero had non-zero offset?");
if (idx != 0) {
auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
}
return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
}
LValue CodeGenFunction::EmitLValueForField(LValue base,
const FieldDecl *field) {
AlignmentSource fieldAlignSource =
getFieldAlignmentSource(base.getAlignmentSource());
if (field->isBitField()) {
const CGRecordLayout &RL =
CGM.getTypes().getCGRecordLayout(field->getParent());
const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
Address Addr = base.getAddress();
unsigned Idx = RL.getLLVMFieldNo(field);
if (Idx != 0)
// For structs, we GEP to the field that the record layout suggests.
Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
field->getName());
// Get the access type.
llvm::Type *FieldIntTy =
llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
if (Addr.getElementType() != FieldIntTy)
Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
QualType fieldType =
field->getType().withCVRQualifiers(base.getVRQualifiers());
return LValue::MakeBitfield(Addr, Info, fieldType, fieldAlignSource);
}
const RecordDecl *rec = field->getParent();
QualType type = field->getType();
bool mayAlias = rec->hasAttr<MayAliasAttr>();
Address addr = base.getAddress();
unsigned cvr = base.getVRQualifiers();
bool TBAAPath = CGM.getCodeGenOpts().StructPathTBAA;
if (rec->isUnion()) {
// For unions, there is no pointer adjustment.
assert(!type->isReferenceType() && "union has reference member");
// TODO: handle path-aware TBAA for union.
TBAAPath = false;
} else {
// For structs, we GEP to the field that the record layout suggests.
addr = emitAddrOfFieldStorage(*this, addr, field);
// 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);
// Loading the reference will disable path-aware TBAA.
TBAAPath = false;
if (CGM.shouldUseTBAA()) {
llvm::MDNode *tbaa;
if (mayAlias)
tbaa = CGM.getTBAAInfo(getContext().CharTy);
else
tbaa = CGM.getTBAAInfo(type);
if (tbaa)
CGM.DecorateInstructionWithTBAA(load, tbaa);
}
mayAlias = false;
type = refType->getPointeeType();
CharUnits alignment =
getNaturalTypeAlignment(type, &fieldAlignSource, /*pointee*/ true);
addr = Address(load, alignment);
// Qualifiers on the struct don't apply to the referencee, and
// we'll pick up CVR from the actual type later, so reset these
// additional qualifiers now.
cvr = 0;
}
}
// 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 = Builder.CreateElementBitCast(addr,
CGM.getTypes().ConvertTypeForMem(type),
field->getName());
if (field->hasAttr<AnnotateAttr>())
addr = EmitFieldAnnotations(field, addr);
LValue LV = MakeAddrLValue(addr, type, fieldAlignSource);
LV.getQuals().addCVRQualifiers(cvr);
if (TBAAPath) {
const ASTRecordLayout &Layout =
getContext().getASTRecordLayout(field->getParent());
// Set the base type to be the base type of the base LValue and
// update offset to be relative to the base type.
LV.setTBAABaseType(mayAlias ? getContext().CharTy : base.getTBAABaseType());
LV.setTBAAOffset(mayAlias ? 0 : base.getTBAAOffset() +
Layout.getFieldOffset(field->getFieldIndex()) /
getContext().getCharWidth());
}
// __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(LValue Base,
const FieldDecl *Field) {
QualType FieldType = Field->getType();
if (!FieldType->isReferenceType())
return EmitLValueForField(Base, Field);
Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
// Make sure that the address is pointing to the right type.
llvm::Type *llvmType = ConvertTypeForMem(FieldType);
V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
// TODO: access-path TBAA?
auto FieldAlignSource = getFieldAlignmentSource(Base.getAlignmentSource());
return MakeAddrLValue(V, FieldType, FieldAlignSource);
}
LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
if (E->isFileScope()) {
ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
}
if (E->getType()->isVariablyModifiedType())
// make sure to emit the VLA size.
EmitVariablyModifiedType(E->getType());
Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
const Expr *InitExpr = E->getInitializer();
LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
/*Init*/ true);
return Result;
}
LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
if (!E->isGLValue())
// Initializing an aggregate temporary in C++11: T{...}.
return EmitAggExprToLValue(E);
// An lvalue initializer list must be initializing a reference.
assert(E->isTransparent() && "non-transparent glvalue init list");
return EmitLValue(E->getInit(0));
}
/// Emit the operand of a glvalue conditional operator. This is either a glvalue
/// or a (possibly-parenthesized) throw-expression. If this is a throw, no
/// LValue is returned and the current block has been terminated.
static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
const Expr *Operand) {
if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
return None;
}
return CGF.EmitLValue(Operand);
}
LValue CodeGenFunction::
EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
if (!expr->isGLValue()) {
// ?: here should be an aggregate.
assert(hasAggregateEvaluationKind(expr->getType()) &&
"Unexpected conditional operator!");
return EmitAggExprToLValue(expr);
}
OpaqueValueMapping binding(*this, 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)) {
// If the true case is live, we need to track its region.
if (CondExprBool)
incrementProfileCounter(expr);
return EmitLValue(live);
}
}
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, getProfileCount(expr));
// Any temporaries created here are conditional.
EmitBlock(lhsBlock);
incrementProfileCounter(expr);
eval.begin(*this);
Optional<LValue> lhs =
EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
eval.end(*this);
if (lhs && !lhs->isSimple())
return EmitUnsupportedLValue(expr, "conditional operator");
lhsBlock = Builder.GetInsertBlock();
if (lhs)
Builder.CreateBr(contBlock);
// Any temporaries created here are conditional.
EmitBlock(rhsBlock);
eval.begin(*this);
Optional<LValue> rhs =
EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
eval.end(*this);
if (rhs && !rhs->isSimple())
return EmitUnsupportedLValue(expr, "conditional operator");
rhsBlock = Builder.GetInsertBlock();
EmitBlock(contBlock);
if (lhs && rhs) {
llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
2, "cond-lvalue");
phi->addIncoming(lhs->getPointer(), lhsBlock);
phi->addIncoming(rhs->getPointer(), rhsBlock);
Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
AlignmentSource alignSource =
std::max(lhs->getAlignmentSource(), rhs->getAlignmentSource());
return MakeAddrLValue(result, expr->getType(), alignSource);
} else {
assert((lhs || rhs) &&
"both operands of glvalue conditional are throw-expressions?");
return lhs ? *lhs : *rhs;
}
}
/// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
/// type. If the cast is to a reference, 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 members. 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:
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_BooleanToSignedIntegral:
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_ReinterpretMemberPointer:
case CK_AnyPointerToBlockPointerCast:
case CK_ARCProduceObject:
case CK_ARCConsumeObject:
case CK_ARCReclaimReturnedObject:
case CK_ARCExtendBlockObject:
case CK_CopyAndAutoreleaseBlockObject:
case CK_AddressSpaceConversion:
case CK_IntToOCLSampler:
return EmitUnsupportedLValue(E, "unexpected cast lvalue");
case CK_Dependent:
llvm_unreachable("dependent cast kind in IR gen!");
case CK_BuiltinFnToFnPtr:
llvm_unreachable("builtin functions are handled elsewhere");
// These are never l-values; just use the aggregate emission code.
case CK_NonAtomicToAtomic:
case CK_AtomicToNonAtomic:
return EmitAggExprToLValue(E);
case CK_Dynamic: {
LValue LV = EmitLValue(E->getSubExpr());
Address V = LV.getAddress();
const auto *DCE = cast<CXXDynamicCastExpr>(E);
return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
}
case CK_ConstructorConversion:
case CK_UserDefinedConversion:
case CK_CPointerToObjCPointerCast:
case CK_BlockPointerToObjCPointerCast:
case CK_NoOp:
case CK_LValueToRValue:
return EmitLValue(E->getSubExpr());
case CK_UncheckedDerivedToBase:
case CK_DerivedToBase: {
const RecordType *DerivedClassTy =
E->getSubExpr()->getType()->getAs<RecordType>();
auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
LValue LV = EmitLValue(E->getSubExpr());
Address This = LV.getAddress();
// Perform the derived-to-base conversion
Address Base = GetAddressOfBaseClass(
This, DerivedClassDecl, E->path_begin(), E->path_end(),
/*NullCheckValue=*/false, E->getExprLoc());
return MakeAddrLValue(Base, E->getType(), LV.getAlignmentSource());
}
case CK_ToUnion:
return EmitAggExprToLValue(E);
case CK_BaseToDerived: {
const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
LValue LV = EmitLValue(E->getSubExpr());
// Perform the base-to-derived conversion
Address Derived =
GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
E->path_begin(), E->path_end(),
/*NullCheckValue=*/false);
// C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
// performed and the object is not of the derived type.
if (sanitizePerformTypeCheck())
EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
Derived.getPointer(), E->getType());
if (SanOpts.has(SanitizerKind::CFIDerivedCast))
EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
/*MayBeNull=*/false,
CFITCK_DerivedCast, E->getLocStart());
return MakeAddrLValue(Derived, E->getType(), LV.getAlignmentSource());
}
case CK_LValueBitCast: {
// This must be a reinterpret_cast (or c-style equivalent).
const auto *CE = cast<ExplicitCastExpr>(E);
CGM.EmitExplicitCastExprType(CE, this);
LValue LV = EmitLValue(E->getSubExpr());
Address V = Builder.CreateBitCast(LV.getAddress(),
ConvertType(CE->getTypeAsWritten()));
if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
/*MayBeNull=*/false,
CFITCK_UnrelatedCast, E->getLocStart());
return MakeAddrLValue(V, E->getType(), LV.getAlignmentSource());
}
case CK_ObjCObjectLValueCast: {
LValue LV = EmitLValue(E->getSubExpr());
Address V = Builder.CreateElementBitCast(LV.getAddress(),
ConvertType(E->getType()));
return MakeAddrLValue(V, E->getType(), LV.getAlignmentSource());
}
case CK_ZeroToOCLEvent:
llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
}
llvm_unreachable("Unhandled lvalue cast kind?");
}
LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
assert(OpaqueValueMappingData::shouldBindAsLValue(e));
return getOpaqueLValueMapping(e);
}
RValue CodeGenFunction::EmitRValueForField(LValue LV,
const FieldDecl *FD,
SourceLocation Loc) {
QualType FT = FD->getType();
LValue FieldLV = EmitLValueForField(LV, FD);
switch (getEvaluationKind(FT)) {
case TEK_Complex:
return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
case TEK_Aggregate:
return FieldLV.asAggregateRValue();
case TEK_Scalar:
// This routine is used to load fields one-by-one to perform a copy, so
// don't load reference fields.
if (FD->getType()->isReferenceType())
return RValue::get(FieldLV.getPointer());
return EmitLoadOfLValue(FieldLV, Loc);
}
llvm_unreachable("bad evaluation kind");
}
//===--------------------------------------------------------------------===//
// Expression Emission
//===--------------------------------------------------------------------===//
RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
ReturnValueSlot ReturnValue) {
// Builtins never have block type.
if (E->getCallee()->getType()->isBlockPointerType())
return EmitBlockCallExpr(E, ReturnValue);
if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
return EmitCXXMemberCallExpr(CE, ReturnValue);
if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
return EmitCUDAKernelCallExpr(CE, ReturnValue);
if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
if (const CXXMethodDecl *MD =
dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
CGCallee callee = EmitCallee(E->getCallee());
if (callee.isBuiltin()) {
return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
E, ReturnValue);
}
if (callee.isPseudoDestructor()) {
return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
}
return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
}
/// Emit a CallExpr without considering whether it might be a subclass.
RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
ReturnValueSlot ReturnValue) {
CGCallee Callee = EmitCallee(E->getCallee());
return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
}
static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
if (auto builtinID = FD->getBuiltinID()) {
return CGCallee::forBuiltin(builtinID, FD);
}
llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
return CGCallee::forDirect(calleePtr, FD);
}
CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
E = E->IgnoreParens();
// Look through function-to-pointer decay.
if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
return EmitCallee(ICE->getSubExpr());
}
// Resolve direct calls.
} else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
return EmitDirectCallee(*this, FD);
}
} else if (auto ME = dyn_cast<MemberExpr>(E)) {
if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
EmitIgnoredExpr(ME->getBase());
return EmitDirectCallee(*this, FD);
}
// Look through template substitutions.
} else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
return EmitCallee(NTTP->getReplacement());
// Treat pseudo-destructor calls differently.
} else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
return CGCallee::forPseudoDestructor(PDE);
}
// Otherwise, we have an indirect reference.
llvm::Value *calleePtr;
QualType functionType;
if (auto ptrType = E->getType()->getAs<PointerType>()) {
calleePtr = EmitScalarExpr(E);
functionType = ptrType->getPointeeType();
} else {
functionType = E->getType();
calleePtr = EmitLValue(E).getPointer();
}
assert(functionType->isFunctionType());
CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(),
E->getReferencedDeclOfCallee());
CGCallee callee(calleeInfo, calleePtr);
return callee;
}
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.
switch (getEvaluationKind(E->getType())) {
case TEK_Scalar: {
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 = EmitCheckedLValue(E->getLHS(), TCK_Store);
EmitStoreThroughLValue(RV, LV);
return LV;
}
case TEK_Complex:
return EmitComplexAssignmentLValue(E);
case TEK_Aggregate:
return EmitAggExprToLValue(E);
}
llvm_unreachable("bad evaluation kind");
}
LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
RValue RV = EmitCallExpr(E);
if (!RV.isScalar())
return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
AlignmentSource::Decl);
assert(E->getCallReturnType(getContext())->isReferenceType() &&
"Can't have a scalar return unless the return type is a "
"reference type!");
return MakeNaturalAlignPointeeAddrLValue(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.getAddress(), E->getType(),
AlignmentSource::Decl);
}
LValue
CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
}
Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
ConvertType(E->getType()));
}
LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
AlignmentSource::Decl);
}
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.getAddress());
return MakeAddrLValue(Slot.getAddress(), E->getType(),
AlignmentSource::Decl);
}
LValue
CodeGenFunction::EmitLambdaLValue(const LambdaExpr *E) {
AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
EmitLambdaExpr(E, Slot);
return MakeAddrLValue(Slot.getAddress(), E->getType(),
AlignmentSource::Decl);
}
LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
RValue RV = EmitObjCMessageExpr(E);
if (!RV.isScalar())
return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
AlignmentSource::Decl);
assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
"Can't have a scalar return unless the return type is a "
"reference type!");
return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
}
LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
Address V =
CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
}
llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
const ObjCIvarDecl *Ivar) {
return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
}
LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
llvm::Value *BaseValue,
const ObjCIvarDecl *Ivar,
unsigned CVRQualifiers) {
return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
Ivar, CVRQualifiers);
}
LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
// FIXME: A lot of the code below could be shared with EmitMemberExpr.
llvm::Value *BaseValue = nullptr;
const Expr *BaseExpr = E->getBase();
Qualifiers BaseQuals;
QualType ObjectTy;
if (E->isArrow()) {
BaseValue = EmitScalarExpr(BaseExpr);
ObjectTy = BaseExpr->getType()->getPointeeType();
BaseQuals = ObjectTy.getQualifiers();
} else {
LValue BaseLV = EmitLValue(BaseExpr);
BaseValue = BaseLV.getPointer();
ObjectTy = BaseExpr->getType();
BaseQuals = ObjectTy.getQualifiers();
}
LValue LV =
EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
BaseQuals.getCVRQualifiers());
setObjCGCLValueClass(getContext(), E, LV);
return LV;
}
LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
// Can only get l-value for message expression returning aggregate type
RValue RV = EmitAnyExprToTemp(E);
return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
AlignmentSource::Decl);
}
RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
const CallExpr *E, ReturnValueSlot ReturnValue,
llvm::Value *Chain) {
// Get the actual function type. The callee type will always be a pointer to
// function type or a block pointer type.
assert(CalleeType->isFunctionPointerType() &&
"Call must have function pointer type!");
const Decl *TargetDecl = OrigCallee.getAbstractInfo().getCalleeDecl();
if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
// We can only guarantee that a function is called from the correct
// context/function based on the appropriate target attributes,
// so only check in the case where we have both always_inline and target
// since otherwise we could be making a conditional call after a check for
// the proper cpu features (and it won't cause code generation issues due to
// function based code generation).
if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
TargetDecl->hasAttr<TargetAttr>())
checkTargetFeatures(E, FD);
CalleeType = getContext().getCanonicalType(CalleeType);
const auto *FnType =
cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
CGCallee Callee = OrigCallee;
if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
(!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
if (llvm::Constant *PrefixSig =
CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
SanitizerScope SanScope(this);
llvm::Constant *FTRTTIConst =
CGM.GetAddrOfRTTIDescriptor(QualType(FnType, 0), /*ForEH=*/true);
llvm::Type *PrefixStructTyElems[] = {
PrefixSig->getType(),
FTRTTIConst->getType()
};
llvm::StructType *PrefixStructTy = llvm::StructType::get(
CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
llvm::Value *CalleePtr = Callee.getFunctionPointer();
llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
llvm::Value *CalleeSigPtr =
Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
llvm::Value *CalleeSig =
Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
llvm::BasicBlock *Cont = createBasicBlock("cont");
llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
EmitBlock(TypeCheck);
llvm::Value *CalleeRTTIPtr =
Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
llvm::Value *CalleeRTTI =
Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
llvm::Value *CalleeRTTIMatch =
Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
llvm::Constant *StaticData[] = {
EmitCheckSourceLocation(E->getLocStart()),
EmitCheckTypeDescriptor(CalleeType)
};
EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
Builder.CreateBr(Cont);
EmitBlock(Cont);
}
}
// If we are checking indirect calls and this call is indirect, check that the
// function pointer is a member of the bit set for the function type.
if (SanOpts.has(SanitizerKind::CFIICall) &&
(!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
SanitizerScope SanScope(this);
EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
llvm::Value *CalleePtr = Callee.getFunctionPointer();
llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
llvm::Value *TypeTest = Builder.CreateCall(
CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
llvm::Constant *StaticData[] = {
llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
EmitCheckSourceLocation(E->getLocStart()),
EmitCheckTypeDescriptor(QualType(FnType, 0)),
};
if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
CastedCallee, StaticData);
} else {
EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
SanitizerHandler::CFICheckFail, StaticData,
{CastedCallee, llvm::UndefValue::get(IntPtrTy)});
}
}
CallArgList Args;
if (Chain)
Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
CGM.getContext().VoidPtrTy);
// C++17 requires that we evaluate arguments to a call using assignment syntax
// right-to-left, and that we evaluate arguments to certain other operators
// left-to-right. Note that we allow this to override the order dictated by
// the calling convention on the MS ABI, which means that parameter
// destruction order is not necessarily reverse construction order.
// FIXME: Revisit this based on C++ committee response to unimplementability.
EvaluationOrder Order = EvaluationOrder::Default;
if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
if (OCE->isAssignmentOp())
Order = EvaluationOrder::ForceRightToLeft;
else {
switch (OCE->getOperator()) {
case OO_LessLess:
case OO_GreaterGreater:
case OO_AmpAmp:
case OO_PipePipe:
case OO_Comma:
case OO_ArrowStar:
Order = EvaluationOrder::ForceLeftToRight;
break;
default:
break;
}
}
}
EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
Args, FnType, /*isChainCall=*/Chain);
// C99 6.5.2.2p6:
// If the expression that denotes the called function has a type
// that does not include a prototype, [the default argument
// promotions are performed]. If the number of arguments does not
// equal the number of parameters, the behavior is undefined. If
// the function is defined with a type that includes a prototype,
// and either the prototype ends with an ellipsis (, ...) or the
// types of the arguments after promotion are not compatible with
// the types of the parameters, the behavior is undefined. If the
// function is defined with a type that does not include a
// prototype, and the types of the arguments after promotion are
// not compatible with those of the parameters after promotion,
// the behavior is undefined [except in some trivial cases].
// That is, in the general case, we should assume that a call
// through an unprototyped function type works like a *non-variadic*
// call. The way we make this work is to cast to the exact type
// of the promoted arguments.
//
// Chain calls use this same code path to add the invisible chain parameter
// to the function type.
if (isa<FunctionNoProtoType>(FnType) || Chain) {
llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
CalleeTy = CalleeTy->getPointerTo();
llvm::Value *CalleePtr = Callee.getFunctionPointer();
CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
Callee.setFunctionPointer(CalleePtr);
}
return EmitCall(FnInfo, Callee, ReturnValue, Args);
}
LValue CodeGenFunction::
EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
Address BaseAddr = Address::invalid();
if (E->getOpcode() == BO_PtrMemI) {
BaseAddr = EmitPointerWithAlignment(E->getLHS());
} else {
BaseAddr = EmitLValue(E->getLHS()).getAddress();
}
llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
const MemberPointerType *MPT
= E->getRHS()->getType()->getAs<MemberPointerType>();
AlignmentSource AlignSource;
Address MemberAddr =
EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT,
&AlignSource);
return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), AlignSource);
}
/// Given the address of a temporary variable, produce an r-value of
/// its type.
RValue CodeGenFunction::convertTempToRValue(Address addr,
QualType type,
SourceLocation loc) {
LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
switch (getEvaluationKind(type)) {
case TEK_Complex:
return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
case TEK_Aggregate:
return lvalue.asAggregateRValue();
case TEK_Scalar:
return RValue::get(EmitLoadOfScalar(lvalue, loc));
}
llvm_unreachable("bad evaluation kind");
}
void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
assert(Val->getType()->isFPOrFPVectorTy());
if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
return;
llvm::MDBuilder MDHelper(getLLVMContext());
llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
}
namespace {
struct LValueOrRValue {
LValue LV;
RValue RV;
};
}
static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
const PseudoObjectExpr *E,
bool forLValue,
AggValueSlot slot) {
SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
// Find the result expression, if any.
const Expr *resultExpr = E->getResultExpr();
LValueOrRValue result;
for (PseudoObjectExpr::const_semantics_iterator
i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
const Expr *semantic = *i;
// If this semantic expression is an opaque value, bind it
// to the result of its source expression.
if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
// If this is the result expression, we may need to evaluate
// directly into the slot.
typedef CodeGenFunction::OpaqueValueMappingData OVMA;
OVMA opaqueData;
if (ov == resultExpr && ov->isRValue() && !forLValue &&
CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
CGF.EmitAggExpr(ov->getSourceExpr(), slot);
LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
AlignmentSource::Decl);
opaqueData = OVMA::bind(CGF, ov, LV);
result.RV = slot.asRValue();
// Otherwise, emit as normal.
} else {
opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
// If this is the result, also evaluate the result now.
if (ov == resultExpr) {
if (forLValue)
result.LV = CGF.EmitLValue(ov);
else
result.RV = CGF.EmitAnyExpr(ov, slot);
}
}
opaques.push_back(opaqueData);
// Otherwise, if the expression is the result, evaluate it
// and remember the result.
} else if (semantic == resultExpr) {
if (forLValue)
result.LV = CGF.EmitLValue(semantic);
else
result.RV = CGF.EmitAnyExpr(semantic, slot);
// Otherwise, evaluate the expression in an ignored context.
} else {
CGF.EmitIgnoredExpr(semantic);
}
}
// Unbind all the opaques now.
for (unsigned i = 0, e = opaques.size(); i != e; ++i)
opaques[i].unbind(CGF);
return result;
}
RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
AggValueSlot slot) {
return emitPseudoObjectExpr(*this, E, false, slot).RV;
}
LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;
}
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