1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code to emit Expr nodes as LLVM code.
12 //===----------------------------------------------------------------------===//
16 #include "CGCleanup.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "CGOpenMPRuntime.h"
20 #include "CGRecordLayout.h"
21 #include "CodeGenFunction.h"
22 #include "CodeGenModule.h"
23 #include "TargetInfo.h"
24 #include "clang/AST/ASTContext.h"
25 #include "clang/AST/Attr.h"
26 #include "clang/AST/DeclObjC.h"
27 #include "clang/AST/NSAPI.h"
28 #include "clang/Frontend/CodeGenOptions.h"
29 #include "llvm/ADT/Hashing.h"
30 #include "llvm/ADT/StringExtras.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/Intrinsics.h"
33 #include "llvm/IR/LLVMContext.h"
34 #include "llvm/IR/MDBuilder.h"
35 #include "llvm/Support/ConvertUTF.h"
36 #include "llvm/Support/MathExtras.h"
37 #include "llvm/Support/Path.h"
38 #include "llvm/Transforms/Utils/SanitizerStats.h"
42 using namespace clang;
43 using namespace CodeGen;
45 //===--------------------------------------------------------------------===//
46 // Miscellaneous Helper Methods
47 //===--------------------------------------------------------------------===//
49 llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
50 unsigned addressSpace =
51 cast<llvm::PointerType>(value->getType())->getAddressSpace();
53 llvm::PointerType *destType = Int8PtrTy;
55 destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
57 if (value->getType() == destType) return value;
58 return Builder.CreateBitCast(value, destType);
61 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
63 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
65 auto Alloca = CreateTempAlloca(Ty, Name);
66 Alloca->setAlignment(Align.getQuantity());
67 return Address(Alloca, Align);
70 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
72 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
74 return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
75 nullptr, Name, AllocaInsertPt);
78 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
79 /// default alignment of the corresponding LLVM type, which is *not*
80 /// guaranteed to be related in any way to the expected alignment of
81 /// an AST type that might have been lowered to Ty.
82 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
85 CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
86 return CreateTempAlloca(Ty, Align, Name);
89 void CodeGenFunction::InitTempAlloca(Address Var, llvm::Value *Init) {
90 assert(isa<llvm::AllocaInst>(Var.getPointer()));
91 auto *Store = new llvm::StoreInst(Init, Var.getPointer());
92 Store->setAlignment(Var.getAlignment().getQuantity());
93 llvm::BasicBlock *Block = AllocaInsertPt->getParent();
94 Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
97 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
98 CharUnits Align = getContext().getTypeAlignInChars(Ty);
99 return CreateTempAlloca(ConvertType(Ty), Align, Name);
102 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name) {
103 // FIXME: Should we prefer the preferred type alignment here?
104 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name);
107 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
109 return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name);
112 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
113 /// expression and compare the result against zero, returning an Int1Ty value.
114 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
115 PGO.setCurrentStmt(E);
116 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
117 llvm::Value *MemPtr = EmitScalarExpr(E);
118 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
121 QualType BoolTy = getContext().BoolTy;
122 SourceLocation Loc = E->getExprLoc();
123 if (!E->getType()->isAnyComplexType())
124 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
126 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
130 /// EmitIgnoredExpr - Emit code to compute the specified expression,
131 /// ignoring the result.
132 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
134 return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
136 // Just emit it as an l-value and drop the result.
140 /// EmitAnyExpr - Emit code to compute the specified expression which
141 /// can have any type. The result is returned as an RValue struct.
142 /// If this is an aggregate expression, AggSlot indicates where the
143 /// result should be returned.
144 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
145 AggValueSlot aggSlot,
147 switch (getEvaluationKind(E->getType())) {
149 return RValue::get(EmitScalarExpr(E, ignoreResult));
151 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
153 if (!ignoreResult && aggSlot.isIgnored())
154 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
155 EmitAggExpr(E, aggSlot);
156 return aggSlot.asRValue();
158 llvm_unreachable("bad evaluation kind");
161 /// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
162 /// always be accessible even if no aggregate location is provided.
163 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
164 AggValueSlot AggSlot = AggValueSlot::ignored();
166 if (hasAggregateEvaluationKind(E->getType()))
167 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
168 return EmitAnyExpr(E, AggSlot);
171 /// EmitAnyExprToMem - Evaluate an expression into a given memory
173 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
177 // FIXME: This function should take an LValue as an argument.
178 switch (getEvaluationKind(E->getType())) {
180 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
184 case TEK_Aggregate: {
185 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
186 AggValueSlot::IsDestructed_t(IsInit),
187 AggValueSlot::DoesNotNeedGCBarriers,
188 AggValueSlot::IsAliased_t(!IsInit)));
193 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
194 LValue LV = MakeAddrLValue(Location, E->getType());
195 EmitStoreThroughLValue(RV, LV);
199 llvm_unreachable("bad evaluation kind");
203 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
204 const Expr *E, Address ReferenceTemporary) {
205 // Objective-C++ ARC:
206 // If we are binding a reference to a temporary that has ownership, we
207 // need to perform retain/release operations on the temporary.
209 // FIXME: This should be looking at E, not M.
210 if (auto Lifetime = M->getType().getObjCLifetime()) {
212 case Qualifiers::OCL_None:
213 case Qualifiers::OCL_ExplicitNone:
214 // Carry on to normal cleanup handling.
217 case Qualifiers::OCL_Autoreleasing:
218 // Nothing to do; cleaned up by an autorelease pool.
221 case Qualifiers::OCL_Strong:
222 case Qualifiers::OCL_Weak:
223 switch (StorageDuration Duration = M->getStorageDuration()) {
225 // Note: we intentionally do not register a cleanup to release
226 // the object on program termination.
230 // FIXME: We should probably register a cleanup in this case.
234 case SD_FullExpression:
235 CodeGenFunction::Destroyer *Destroy;
236 CleanupKind CleanupKind;
237 if (Lifetime == Qualifiers::OCL_Strong) {
238 const ValueDecl *VD = M->getExtendingDecl();
240 VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
241 CleanupKind = CGF.getARCCleanupKind();
242 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
243 : &CodeGenFunction::destroyARCStrongImprecise;
245 // __weak objects always get EH cleanups; otherwise, exceptions
246 // could cause really nasty crashes instead of mere leaks.
247 CleanupKind = NormalAndEHCleanup;
248 Destroy = &CodeGenFunction::destroyARCWeak;
250 if (Duration == SD_FullExpression)
251 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
252 M->getType(), *Destroy,
253 CleanupKind & EHCleanup);
255 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
257 *Destroy, CleanupKind & EHCleanup);
261 llvm_unreachable("temporary cannot have dynamic storage duration");
263 llvm_unreachable("unknown storage duration");
267 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
268 if (const RecordType *RT =
269 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
270 // Get the destructor for the reference temporary.
271 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
272 if (!ClassDecl->hasTrivialDestructor())
273 ReferenceTemporaryDtor = ClassDecl->getDestructor();
276 if (!ReferenceTemporaryDtor)
279 // Call the destructor for the temporary.
280 switch (M->getStorageDuration()) {
283 llvm::Constant *CleanupFn;
284 llvm::Constant *CleanupArg;
285 if (E->getType()->isArrayType()) {
286 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
287 ReferenceTemporary, E->getType(),
288 CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
289 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
290 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
292 CleanupFn = CGF.CGM.getAddrOfCXXStructor(ReferenceTemporaryDtor,
293 StructorType::Complete);
294 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
296 CGF.CGM.getCXXABI().registerGlobalDtor(
297 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
301 case SD_FullExpression:
302 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
303 CodeGenFunction::destroyCXXObject,
304 CGF.getLangOpts().Exceptions);
308 CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
309 ReferenceTemporary, E->getType(),
310 CodeGenFunction::destroyCXXObject,
311 CGF.getLangOpts().Exceptions);
315 llvm_unreachable("temporary cannot have dynamic storage duration");
320 createReferenceTemporary(CodeGenFunction &CGF,
321 const MaterializeTemporaryExpr *M, const Expr *Inner) {
322 switch (M->getStorageDuration()) {
323 case SD_FullExpression:
325 // If we have a constant temporary array or record try to promote it into a
326 // constant global under the same rules a normal constant would've been
327 // promoted. This is easier on the optimizer and generally emits fewer
329 QualType Ty = Inner->getType();
330 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
331 (Ty->isArrayType() || Ty->isRecordType()) &&
332 CGF.CGM.isTypeConstant(Ty, true))
333 if (llvm::Constant *Init = CGF.CGM.EmitConstantExpr(Inner, Ty, &CGF)) {
334 auto *GV = new llvm::GlobalVariable(
335 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
336 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp");
337 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
338 GV->setAlignment(alignment.getQuantity());
339 // FIXME: Should we put the new global into a COMDAT?
340 return Address(GV, alignment);
342 return CGF.CreateMemTemp(Ty, "ref.tmp");
346 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
349 llvm_unreachable("temporary can't have dynamic storage duration");
351 llvm_unreachable("unknown storage duration");
354 LValue CodeGenFunction::
355 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
356 const Expr *E = M->GetTemporaryExpr();
358 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
359 // as that will cause the lifetime adjustment to be lost for ARC
360 auto ownership = M->getType().getObjCLifetime();
361 if (ownership != Qualifiers::OCL_None &&
362 ownership != Qualifiers::OCL_ExplicitNone) {
363 Address Object = createReferenceTemporary(*this, M, E);
364 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
365 Object = Address(llvm::ConstantExpr::getBitCast(Var,
366 ConvertTypeForMem(E->getType())
367 ->getPointerTo(Object.getAddressSpace())),
368 Object.getAlignment());
370 // createReferenceTemporary will promote the temporary to a global with a
371 // constant initializer if it can. It can only do this to a value of
372 // ARC-manageable type if the value is global and therefore "immune" to
373 // ref-counting operations. Therefore we have no need to emit either a
374 // dynamic initialization or a cleanup and we can just return the address
376 if (Var->hasInitializer())
377 return MakeAddrLValue(Object, M->getType(),
378 LValueBaseInfo(AlignmentSource::Decl, false));
380 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
382 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
383 LValueBaseInfo(AlignmentSource::Decl,
386 switch (getEvaluationKind(E->getType())) {
387 default: llvm_unreachable("expected scalar or aggregate expression");
389 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
391 case TEK_Aggregate: {
392 EmitAggExpr(E, AggValueSlot::forAddr(Object,
393 E->getType().getQualifiers(),
394 AggValueSlot::IsDestructed,
395 AggValueSlot::DoesNotNeedGCBarriers,
396 AggValueSlot::IsNotAliased));
401 pushTemporaryCleanup(*this, M, E, Object);
405 SmallVector<const Expr *, 2> CommaLHSs;
406 SmallVector<SubobjectAdjustment, 2> Adjustments;
407 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
409 for (const auto &Ignored : CommaLHSs)
410 EmitIgnoredExpr(Ignored);
412 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
413 if (opaque->getType()->isRecordType()) {
414 assert(Adjustments.empty());
415 return EmitOpaqueValueLValue(opaque);
419 // Create and initialize the reference temporary.
420 Address Object = createReferenceTemporary(*this, M, E);
421 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
422 Object = Address(llvm::ConstantExpr::getBitCast(
423 Var, ConvertTypeForMem(E->getType())->getPointerTo()),
424 Object.getAlignment());
425 // If the temporary is a global and has a constant initializer or is a
426 // constant temporary that we promoted to a global, we may have already
428 if (!Var->hasInitializer()) {
429 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
430 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
433 switch (M->getStorageDuration()) {
435 case SD_FullExpression:
436 if (auto *Size = EmitLifetimeStart(
437 CGM.getDataLayout().getTypeAllocSize(Object.getElementType()),
438 Object.getPointer())) {
439 if (M->getStorageDuration() == SD_Automatic)
440 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
443 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Object,
450 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
452 pushTemporaryCleanup(*this, M, E, Object);
454 // Perform derived-to-base casts and/or field accesses, to get from the
455 // temporary object we created (and, potentially, for which we extended
456 // the lifetime) to the subobject we're binding the reference to.
457 for (unsigned I = Adjustments.size(); I != 0; --I) {
458 SubobjectAdjustment &Adjustment = Adjustments[I-1];
459 switch (Adjustment.Kind) {
460 case SubobjectAdjustment::DerivedToBaseAdjustment:
462 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
463 Adjustment.DerivedToBase.BasePath->path_begin(),
464 Adjustment.DerivedToBase.BasePath->path_end(),
465 /*NullCheckValue=*/ false, E->getExprLoc());
468 case SubobjectAdjustment::FieldAdjustment: {
469 LValue LV = MakeAddrLValue(Object, E->getType(),
470 LValueBaseInfo(AlignmentSource::Decl, false));
471 LV = EmitLValueForField(LV, Adjustment.Field);
472 assert(LV.isSimple() &&
473 "materialized temporary field is not a simple lvalue");
474 Object = LV.getAddress();
478 case SubobjectAdjustment::MemberPointerAdjustment: {
479 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
480 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
487 return MakeAddrLValue(Object, M->getType(),
488 LValueBaseInfo(AlignmentSource::Decl, false));
492 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
493 // Emit the expression as an lvalue.
494 LValue LV = EmitLValue(E);
495 assert(LV.isSimple());
496 llvm::Value *Value = LV.getPointer();
498 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
499 // C++11 [dcl.ref]p5 (as amended by core issue 453):
500 // If a glvalue to which a reference is directly bound designates neither
501 // an existing object or function of an appropriate type nor a region of
502 // storage of suitable size and alignment to contain an object of the
503 // reference's type, the behavior is undefined.
504 QualType Ty = E->getType();
505 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
508 return RValue::get(Value);
512 /// getAccessedFieldNo - Given an encoded value and a result number, return the
513 /// input field number being accessed.
514 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
515 const llvm::Constant *Elts) {
516 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
520 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
521 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
523 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
524 llvm::Value *K47 = Builder.getInt64(47);
525 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
526 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
527 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
528 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
529 return Builder.CreateMul(B1, KMul);
532 bool CodeGenFunction::sanitizePerformTypeCheck() const {
533 return SanOpts.has(SanitizerKind::Null) |
534 SanOpts.has(SanitizerKind::Alignment) |
535 SanOpts.has(SanitizerKind::ObjectSize) |
536 SanOpts.has(SanitizerKind::Vptr);
539 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
540 llvm::Value *Ptr, QualType Ty,
542 SanitizerSet SkippedChecks) {
543 if (!sanitizePerformTypeCheck())
546 // Don't check pointers outside the default address space. The null check
547 // isn't correct, the object-size check isn't supported by LLVM, and we can't
548 // communicate the addresses to the runtime handler for the vptr check.
549 if (Ptr->getType()->getPointerAddressSpace())
552 SanitizerScope SanScope(this);
554 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
555 llvm::BasicBlock *Done = nullptr;
557 // Quickly determine whether we have a pointer to an alloca. It's possible
558 // to skip null checks, and some alignment checks, for these pointers. This
559 // can reduce compile-time significantly.
561 dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
563 bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
564 TCK == TCK_UpcastToVirtualBase;
565 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
566 !SkippedChecks.has(SanitizerKind::Null) && !PtrToAlloca) {
567 // The glvalue must not be an empty glvalue.
568 llvm::Value *IsNonNull = Builder.CreateIsNotNull(Ptr);
570 // The IR builder can constant-fold the null check if the pointer points to
573 IsNonNull == llvm::ConstantInt::getTrue(getLLVMContext());
575 // Skip the null check if the pointer is known to be non-null.
577 if (AllowNullPointers) {
578 // When performing pointer casts, it's OK if the value is null.
579 // Skip the remaining checks in that case.
580 Done = createBasicBlock("null");
581 llvm::BasicBlock *Rest = createBasicBlock("not.null");
582 Builder.CreateCondBr(IsNonNull, Rest, Done);
585 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
590 if (SanOpts.has(SanitizerKind::ObjectSize) &&
591 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
592 !Ty->isIncompleteType()) {
593 uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
595 // The glvalue must refer to a large enough storage region.
596 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
598 // FIXME: Get object address space
599 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
600 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
601 llvm::Value *Min = Builder.getFalse();
602 llvm::Value *NullIsUnknown = Builder.getFalse();
603 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
604 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
605 Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown}),
606 llvm::ConstantInt::get(IntPtrTy, Size));
607 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
610 uint64_t AlignVal = 0;
612 if (SanOpts.has(SanitizerKind::Alignment) &&
613 !SkippedChecks.has(SanitizerKind::Alignment)) {
614 AlignVal = Alignment.getQuantity();
615 if (!Ty->isIncompleteType() && !AlignVal)
616 AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
618 // The glvalue must be suitably aligned.
620 (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
622 Builder.CreateAnd(Builder.CreatePtrToInt(Ptr, IntPtrTy),
623 llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
624 llvm::Value *Aligned =
625 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
626 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
630 if (Checks.size() > 0) {
631 // Make sure we're not losing information. Alignment needs to be a power of
633 assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
634 llvm::Constant *StaticData[] = {
635 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
636 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
637 llvm::ConstantInt::get(Int8Ty, TCK)};
638 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData, Ptr);
641 // If possible, check that the vptr indicates that there is a subobject of
642 // type Ty at offset zero within this object.
644 // C++11 [basic.life]p5,6:
645 // [For storage which does not refer to an object within its lifetime]
646 // The program has undefined behavior if:
647 // -- the [pointer or glvalue] is used to access a non-static data member
648 // or call a non-static member function
649 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
650 if (SanOpts.has(SanitizerKind::Vptr) &&
651 !SkippedChecks.has(SanitizerKind::Vptr) &&
652 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
653 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
654 TCK == TCK_UpcastToVirtualBase) &&
655 RD && RD->hasDefinition() && RD->isDynamicClass()) {
656 // Compute a hash of the mangled name of the type.
658 // FIXME: This is not guaranteed to be deterministic! Move to a
659 // fingerprinting mechanism once LLVM provides one. For the time
660 // being the implementation happens to be deterministic.
661 SmallString<64> MangledName;
662 llvm::raw_svector_ostream Out(MangledName);
663 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
666 // Blacklist based on the mangled type.
667 if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
669 llvm::hash_code TypeHash = hash_value(Out.str());
671 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
672 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
673 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
674 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
675 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
676 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
678 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
679 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
681 // Look the hash up in our cache.
682 const int CacheSize = 128;
683 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
684 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
685 "__ubsan_vptr_type_cache");
686 llvm::Value *Slot = Builder.CreateAnd(Hash,
687 llvm::ConstantInt::get(IntPtrTy,
689 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
690 llvm::Value *CacheVal =
691 Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
694 // If the hash isn't in the cache, call a runtime handler to perform the
695 // hard work of checking whether the vptr is for an object of the right
696 // type. This will either fill in the cache and return, or produce a
698 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
699 llvm::Constant *StaticData[] = {
700 EmitCheckSourceLocation(Loc),
701 EmitCheckTypeDescriptor(Ty),
702 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
703 llvm::ConstantInt::get(Int8Ty, TCK)
705 llvm::Value *DynamicData[] = { Ptr, Hash };
706 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
707 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
713 Builder.CreateBr(Done);
718 /// Determine whether this expression refers to a flexible array member in a
719 /// struct. We disable array bounds checks for such members.
720 static bool isFlexibleArrayMemberExpr(const Expr *E) {
721 // For compatibility with existing code, we treat arrays of length 0 or
722 // 1 as flexible array members.
723 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
724 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
725 if (CAT->getSize().ugt(1))
727 } else if (!isa<IncompleteArrayType>(AT))
730 E = E->IgnoreParens();
732 // A flexible array member must be the last member in the class.
733 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
734 // FIXME: If the base type of the member expr is not FD->getParent(),
735 // this should not be treated as a flexible array member access.
736 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
737 RecordDecl::field_iterator FI(
738 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
739 return ++FI == FD->getParent()->field_end();
741 } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
742 return IRE->getDecl()->getNextIvar() == nullptr;
748 /// If Base is known to point to the start of an array, return the length of
749 /// that array. Return 0 if the length cannot be determined.
750 static llvm::Value *getArrayIndexingBound(
751 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
752 // For the vector indexing extension, the bound is the number of elements.
753 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
754 IndexedType = Base->getType();
755 return CGF.Builder.getInt32(VT->getNumElements());
758 Base = Base->IgnoreParens();
760 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
761 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
762 !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
763 IndexedType = CE->getSubExpr()->getType();
764 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
765 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
766 return CGF.Builder.getInt(CAT->getSize());
767 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
768 return CGF.getVLASize(VAT).first;
775 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
776 llvm::Value *Index, QualType IndexType,
778 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
779 "should not be called unless adding bounds checks");
780 SanitizerScope SanScope(this);
782 QualType IndexedType;
783 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
787 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
788 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
789 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
791 llvm::Constant *StaticData[] = {
792 EmitCheckSourceLocation(E->getExprLoc()),
793 EmitCheckTypeDescriptor(IndexedType),
794 EmitCheckTypeDescriptor(IndexType)
796 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
797 : Builder.CreateICmpULE(IndexVal, BoundVal);
798 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
799 SanitizerHandler::OutOfBounds, StaticData, Index);
803 CodeGenFunction::ComplexPairTy CodeGenFunction::
804 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
805 bool isInc, bool isPre) {
806 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
808 llvm::Value *NextVal;
809 if (isa<llvm::IntegerType>(InVal.first->getType())) {
810 uint64_t AmountVal = isInc ? 1 : -1;
811 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
813 // Add the inc/dec to the real part.
814 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
816 QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
817 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
820 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
822 // Add the inc/dec to the real part.
823 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
826 ComplexPairTy IncVal(NextVal, InVal.second);
828 // Store the updated result through the lvalue.
829 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
831 // If this is a postinc, return the value read from memory, otherwise use the
833 return isPre ? IncVal : InVal;
836 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
837 CodeGenFunction *CGF) {
838 // Bind VLAs in the cast type.
839 if (CGF && E->getType()->isVariablyModifiedType())
840 CGF->EmitVariablyModifiedType(E->getType());
842 if (CGDebugInfo *DI = getModuleDebugInfo())
843 DI->EmitExplicitCastType(E->getType());
846 //===----------------------------------------------------------------------===//
847 // LValue Expression Emission
848 //===----------------------------------------------------------------------===//
850 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
851 /// derive a more accurate bound on the alignment of the pointer.
852 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
853 LValueBaseInfo *BaseInfo) {
854 // We allow this with ObjC object pointers because of fragile ABIs.
855 assert(E->getType()->isPointerType() ||
856 E->getType()->isObjCObjectPointerType());
857 E = E->IgnoreParens();
860 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
861 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
862 CGM.EmitExplicitCastExprType(ECE, this);
864 switch (CE->getCastKind()) {
865 // Non-converting casts (but not C's implicit conversion from void*).
868 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
869 if (PtrTy->getPointeeType()->isVoidType())
872 LValueBaseInfo InnerInfo;
873 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), &InnerInfo);
874 if (BaseInfo) *BaseInfo = InnerInfo;
876 // If this is an explicit bitcast, and the source l-value is
877 // opaque, honor the alignment of the casted-to type.
878 if (isa<ExplicitCastExpr>(CE) &&
879 InnerInfo.getAlignmentSource() != AlignmentSource::Decl) {
880 LValueBaseInfo ExpInfo;
881 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
884 BaseInfo->mergeForCast(ExpInfo);
885 Addr = Address(Addr.getPointer(), Align);
888 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
889 CE->getCastKind() == CK_BitCast) {
890 if (auto PT = E->getType()->getAs<PointerType>())
891 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
893 CodeGenFunction::CFITCK_UnrelatedCast,
897 return Builder.CreateBitCast(Addr, ConvertType(E->getType()));
901 // Array-to-pointer decay.
902 case CK_ArrayToPointerDecay:
903 return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo);
905 // Derived-to-base conversions.
906 case CK_UncheckedDerivedToBase:
907 case CK_DerivedToBase: {
908 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
909 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
910 return GetAddressOfBaseClass(Addr, Derived,
911 CE->path_begin(), CE->path_end(),
912 ShouldNullCheckClassCastValue(CE),
916 // TODO: Is there any reason to treat base-to-derived conversions
924 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
925 if (UO->getOpcode() == UO_AddrOf) {
926 LValue LV = EmitLValue(UO->getSubExpr());
927 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
928 return LV.getAddress();
932 // TODO: conditional operators, comma.
934 // Otherwise, use the alignment of the type.
935 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo);
936 return Address(EmitScalarExpr(E), Align);
939 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
940 if (Ty->isVoidType())
941 return RValue::get(nullptr);
943 switch (getEvaluationKind(Ty)) {
946 ConvertType(Ty->castAs<ComplexType>()->getElementType());
947 llvm::Value *U = llvm::UndefValue::get(EltTy);
948 return RValue::getComplex(std::make_pair(U, U));
951 // If this is a use of an undefined aggregate type, the aggregate must have an
952 // identifiable address. Just because the contents of the value are undefined
953 // doesn't mean that the address can't be taken and compared.
954 case TEK_Aggregate: {
955 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
956 return RValue::getAggregate(DestPtr);
960 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
962 llvm_unreachable("bad evaluation kind");
965 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
967 ErrorUnsupported(E, Name);
968 return GetUndefRValue(E->getType());
971 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
973 ErrorUnsupported(E, Name);
974 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
975 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
979 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
980 const Expr *Base = Obj;
981 while (!isa<CXXThisExpr>(Base)) {
982 // The result of a dynamic_cast can be null.
983 if (isa<CXXDynamicCastExpr>(Base))
986 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
987 Base = CE->getSubExpr();
988 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
989 Base = PE->getSubExpr();
990 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
991 if (UO->getOpcode() == UO_Extension)
992 Base = UO->getSubExpr();
1002 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1004 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1005 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1008 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1009 SanitizerSet SkippedChecks;
1010 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1011 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1013 SkippedChecks.set(SanitizerKind::Alignment, true);
1014 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1015 SkippedChecks.set(SanitizerKind::Null, true);
1017 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1018 E->getType(), LV.getAlignment(), SkippedChecks);
1023 /// EmitLValue - Emit code to compute a designator that specifies the location
1024 /// of the expression.
1026 /// This can return one of two things: a simple address or a bitfield reference.
1027 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1028 /// an LLVM pointer type.
1030 /// If this returns a bitfield reference, nothing about the pointee type of the
1031 /// LLVM value is known: For example, it may not be a pointer to an integer.
1033 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1034 /// this method guarantees that the returned pointer type will point to an LLVM
1035 /// type of the same size of the lvalue's type. If the lvalue has a variable
1036 /// length type, this is not possible.
1038 LValue CodeGenFunction::EmitLValue(const Expr *E) {
1039 ApplyDebugLocation DL(*this, E);
1040 switch (E->getStmtClass()) {
1041 default: return EmitUnsupportedLValue(E, "l-value expression");
1043 case Expr::ObjCPropertyRefExprClass:
1044 llvm_unreachable("cannot emit a property reference directly");
1046 case Expr::ObjCSelectorExprClass:
1047 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1048 case Expr::ObjCIsaExprClass:
1049 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1050 case Expr::BinaryOperatorClass:
1051 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1052 case Expr::CompoundAssignOperatorClass: {
1053 QualType Ty = E->getType();
1054 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1055 Ty = AT->getValueType();
1056 if (!Ty->isAnyComplexType())
1057 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1058 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1060 case Expr::CallExprClass:
1061 case Expr::CXXMemberCallExprClass:
1062 case Expr::CXXOperatorCallExprClass:
1063 case Expr::UserDefinedLiteralClass:
1064 return EmitCallExprLValue(cast<CallExpr>(E));
1065 case Expr::VAArgExprClass:
1066 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1067 case Expr::DeclRefExprClass:
1068 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1069 case Expr::ParenExprClass:
1070 return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1071 case Expr::GenericSelectionExprClass:
1072 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1073 case Expr::PredefinedExprClass:
1074 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1075 case Expr::StringLiteralClass:
1076 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1077 case Expr::ObjCEncodeExprClass:
1078 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1079 case Expr::PseudoObjectExprClass:
1080 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1081 case Expr::InitListExprClass:
1082 return EmitInitListLValue(cast<InitListExpr>(E));
1083 case Expr::CXXTemporaryObjectExprClass:
1084 case Expr::CXXConstructExprClass:
1085 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1086 case Expr::CXXBindTemporaryExprClass:
1087 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1088 case Expr::CXXUuidofExprClass:
1089 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1090 case Expr::LambdaExprClass:
1091 return EmitLambdaLValue(cast<LambdaExpr>(E));
1093 case Expr::ExprWithCleanupsClass: {
1094 const auto *cleanups = cast<ExprWithCleanups>(E);
1095 enterFullExpression(cleanups);
1096 RunCleanupsScope Scope(*this);
1097 LValue LV = EmitLValue(cleanups->getSubExpr());
1098 if (LV.isSimple()) {
1099 // Defend against branches out of gnu statement expressions surrounded by
1101 llvm::Value *V = LV.getPointer();
1102 Scope.ForceCleanup({&V});
1103 return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1104 getContext(), LV.getBaseInfo(),
1107 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1108 // bitfield lvalue or some other non-simple lvalue?
1112 case Expr::CXXDefaultArgExprClass:
1113 return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1114 case Expr::CXXDefaultInitExprClass: {
1115 CXXDefaultInitExprScope Scope(*this);
1116 return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1118 case Expr::CXXTypeidExprClass:
1119 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1121 case Expr::ObjCMessageExprClass:
1122 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1123 case Expr::ObjCIvarRefExprClass:
1124 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1125 case Expr::StmtExprClass:
1126 return EmitStmtExprLValue(cast<StmtExpr>(E));
1127 case Expr::UnaryOperatorClass:
1128 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1129 case Expr::ArraySubscriptExprClass:
1130 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1131 case Expr::OMPArraySectionExprClass:
1132 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1133 case Expr::ExtVectorElementExprClass:
1134 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1135 case Expr::MemberExprClass:
1136 return EmitMemberExpr(cast<MemberExpr>(E));
1137 case Expr::CompoundLiteralExprClass:
1138 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1139 case Expr::ConditionalOperatorClass:
1140 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1141 case Expr::BinaryConditionalOperatorClass:
1142 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1143 case Expr::ChooseExprClass:
1144 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1145 case Expr::OpaqueValueExprClass:
1146 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1147 case Expr::SubstNonTypeTemplateParmExprClass:
1148 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1149 case Expr::ImplicitCastExprClass:
1150 case Expr::CStyleCastExprClass:
1151 case Expr::CXXFunctionalCastExprClass:
1152 case Expr::CXXStaticCastExprClass:
1153 case Expr::CXXDynamicCastExprClass:
1154 case Expr::CXXReinterpretCastExprClass:
1155 case Expr::CXXConstCastExprClass:
1156 case Expr::ObjCBridgedCastExprClass:
1157 return EmitCastLValue(cast<CastExpr>(E));
1159 case Expr::MaterializeTemporaryExprClass:
1160 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1164 /// Given an object of the given canonical type, can we safely copy a
1165 /// value out of it based on its initializer?
1166 static bool isConstantEmittableObjectType(QualType type) {
1167 assert(type.isCanonical());
1168 assert(!type->isReferenceType());
1170 // Must be const-qualified but non-volatile.
1171 Qualifiers qs = type.getLocalQualifiers();
1172 if (!qs.hasConst() || qs.hasVolatile()) return false;
1174 // Otherwise, all object types satisfy this except C++ classes with
1175 // mutable subobjects or non-trivial copy/destroy behavior.
1176 if (const auto *RT = dyn_cast<RecordType>(type))
1177 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1178 if (RD->hasMutableFields() || !RD->isTrivial())
1184 /// Can we constant-emit a load of a reference to a variable of the
1185 /// given type? This is different from predicates like
1186 /// Decl::isUsableInConstantExpressions because we do want it to apply
1187 /// in situations that don't necessarily satisfy the language's rules
1188 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1189 /// to do this with const float variables even if those variables
1190 /// aren't marked 'constexpr'.
1191 enum ConstantEmissionKind {
1193 CEK_AsReferenceOnly,
1194 CEK_AsValueOrReference,
1197 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1198 type = type.getCanonicalType();
1199 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1200 if (isConstantEmittableObjectType(ref->getPointeeType()))
1201 return CEK_AsValueOrReference;
1202 return CEK_AsReferenceOnly;
1204 if (isConstantEmittableObjectType(type))
1205 return CEK_AsValueOnly;
1209 /// Try to emit a reference to the given value without producing it as
1210 /// an l-value. This is actually more than an optimization: we can't
1211 /// produce an l-value for variables that we never actually captured
1212 /// in a block or lambda, which means const int variables or constexpr
1213 /// literals or similar.
1214 CodeGenFunction::ConstantEmission
1215 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1216 ValueDecl *value = refExpr->getDecl();
1218 // The value needs to be an enum constant or a constant variable.
1219 ConstantEmissionKind CEK;
1220 if (isa<ParmVarDecl>(value)) {
1222 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1223 CEK = checkVarTypeForConstantEmission(var->getType());
1224 } else if (isa<EnumConstantDecl>(value)) {
1225 CEK = CEK_AsValueOnly;
1229 if (CEK == CEK_None) return ConstantEmission();
1231 Expr::EvalResult result;
1232 bool resultIsReference;
1233 QualType resultType;
1235 // It's best to evaluate all the way as an r-value if that's permitted.
1236 if (CEK != CEK_AsReferenceOnly &&
1237 refExpr->EvaluateAsRValue(result, getContext())) {
1238 resultIsReference = false;
1239 resultType = refExpr->getType();
1241 // Otherwise, try to evaluate as an l-value.
1242 } else if (CEK != CEK_AsValueOnly &&
1243 refExpr->EvaluateAsLValue(result, getContext())) {
1244 resultIsReference = true;
1245 resultType = value->getType();
1249 return ConstantEmission();
1252 // In any case, if the initializer has side-effects, abandon ship.
1253 if (result.HasSideEffects)
1254 return ConstantEmission();
1256 // Emit as a constant.
1257 llvm::Constant *C = CGM.EmitConstantValue(result.Val, resultType, this);
1259 // Make sure we emit a debug reference to the global variable.
1260 // This should probably fire even for
1261 if (isa<VarDecl>(value)) {
1262 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1263 EmitDeclRefExprDbgValue(refExpr, result.Val);
1265 assert(isa<EnumConstantDecl>(value));
1266 EmitDeclRefExprDbgValue(refExpr, result.Val);
1269 // If we emitted a reference constant, we need to dereference that.
1270 if (resultIsReference)
1271 return ConstantEmission::forReference(C);
1273 return ConstantEmission::forValue(C);
1276 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1277 SourceLocation Loc) {
1278 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1279 lvalue.getType(), Loc, lvalue.getBaseInfo(),
1280 lvalue.getTBAAInfo(),
1281 lvalue.getTBAABaseType(), lvalue.getTBAAOffset(),
1282 lvalue.isNontemporal());
1285 static bool hasBooleanRepresentation(QualType Ty) {
1286 if (Ty->isBooleanType())
1289 if (const EnumType *ET = Ty->getAs<EnumType>())
1290 return ET->getDecl()->getIntegerType()->isBooleanType();
1292 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1293 return hasBooleanRepresentation(AT->getValueType());
1298 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1299 llvm::APInt &Min, llvm::APInt &End,
1300 bool StrictEnums, bool IsBool) {
1301 const EnumType *ET = Ty->getAs<EnumType>();
1302 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1303 ET && !ET->getDecl()->isFixed();
1304 if (!IsBool && !IsRegularCPlusPlusEnum)
1308 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1309 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1311 const EnumDecl *ED = ET->getDecl();
1312 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1313 unsigned Bitwidth = LTy->getScalarSizeInBits();
1314 unsigned NumNegativeBits = ED->getNumNegativeBits();
1315 unsigned NumPositiveBits = ED->getNumPositiveBits();
1317 if (NumNegativeBits) {
1318 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1319 assert(NumBits <= Bitwidth);
1320 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1323 assert(NumPositiveBits <= Bitwidth);
1324 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1325 Min = llvm::APInt(Bitwidth, 0);
1331 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1332 llvm::APInt Min, End;
1333 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1334 hasBooleanRepresentation(Ty)))
1337 llvm::MDBuilder MDHelper(getLLVMContext());
1338 return MDHelper.createRange(Min, End);
1341 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1342 SourceLocation Loc) {
1343 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1344 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1345 if (!HasBoolCheck && !HasEnumCheck)
1348 bool IsBool = hasBooleanRepresentation(Ty) ||
1349 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1350 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1351 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1352 if (!NeedsBoolCheck && !NeedsEnumCheck)
1355 // Single-bit booleans don't need to be checked. Special-case this to avoid
1356 // a bit width mismatch when handling bitfield values. This is handled by
1357 // EmitFromMemory for the non-bitfield case.
1359 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1362 llvm::APInt Min, End;
1363 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1366 SanitizerScope SanScope(this);
1370 Check = Builder.CreateICmpULE(
1371 Value, llvm::ConstantInt::get(getLLVMContext(), End));
1373 llvm::Value *Upper = Builder.CreateICmpSLE(
1374 Value, llvm::ConstantInt::get(getLLVMContext(), End));
1375 llvm::Value *Lower = Builder.CreateICmpSGE(
1376 Value, llvm::ConstantInt::get(getLLVMContext(), Min));
1377 Check = Builder.CreateAnd(Upper, Lower);
1379 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1380 EmitCheckTypeDescriptor(Ty)};
1381 SanitizerMask Kind =
1382 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1383 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1384 StaticArgs, EmitCheckValue(Value));
1388 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1391 LValueBaseInfo BaseInfo,
1392 llvm::MDNode *TBAAInfo,
1393 QualType TBAABaseType,
1394 uint64_t TBAAOffset,
1395 bool isNontemporal) {
1396 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1397 // For better performance, handle vector loads differently.
1398 if (Ty->isVectorType()) {
1399 const llvm::Type *EltTy = Addr.getElementType();
1401 const auto *VTy = cast<llvm::VectorType>(EltTy);
1403 // Handle vectors of size 3 like size 4 for better performance.
1404 if (VTy->getNumElements() == 3) {
1406 // Bitcast to vec4 type.
1407 llvm::VectorType *vec4Ty =
1408 llvm::VectorType::get(VTy->getElementType(), 4);
1409 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1411 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1413 // Shuffle vector to get vec3.
1414 V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1415 {0, 1, 2}, "extractVec");
1416 return EmitFromMemory(V, Ty);
1421 // Atomic operations have to be done on integral types.
1422 LValue AtomicLValue =
1423 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1424 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1425 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1428 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1429 if (isNontemporal) {
1430 llvm::MDNode *Node = llvm::MDNode::get(
1431 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1432 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1435 bool MayAlias = BaseInfo.getMayAlias();
1436 llvm::MDNode *TBAA = MayAlias
1437 ? CGM.getTBAAInfo(getContext().CharTy)
1438 : CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo, TBAAOffset);
1440 CGM.DecorateInstructionWithTBAA(Load, TBAA, MayAlias);
1443 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1444 // In order to prevent the optimizer from throwing away the check, don't
1445 // attach range metadata to the load.
1446 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1447 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1448 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1450 return EmitFromMemory(Load, Ty);
1453 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1454 // Bool has a different representation in memory than in registers.
1455 if (hasBooleanRepresentation(Ty)) {
1456 // This should really always be an i1, but sometimes it's already
1457 // an i8, and it's awkward to track those cases down.
1458 if (Value->getType()->isIntegerTy(1))
1459 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1460 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1461 "wrong value rep of bool");
1467 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1468 // Bool has a different representation in memory than in registers.
1469 if (hasBooleanRepresentation(Ty)) {
1470 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1471 "wrong value rep of bool");
1472 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1478 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1479 bool Volatile, QualType Ty,
1480 LValueBaseInfo BaseInfo,
1481 llvm::MDNode *TBAAInfo,
1482 bool isInit, QualType TBAABaseType,
1483 uint64_t TBAAOffset,
1484 bool isNontemporal) {
1486 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1487 // Handle vectors differently to get better performance.
1488 if (Ty->isVectorType()) {
1489 llvm::Type *SrcTy = Value->getType();
1490 auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1491 // Handle vec3 special.
1492 if (VecTy && VecTy->getNumElements() == 3) {
1493 // Our source is a vec3, do a shuffle vector to make it a vec4.
1494 llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1495 Builder.getInt32(2),
1496 llvm::UndefValue::get(Builder.getInt32Ty())};
1497 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1498 Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1499 MaskV, "extractVec");
1500 SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1502 if (Addr.getElementType() != SrcTy) {
1503 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1508 Value = EmitToMemory(Value, Ty);
1510 LValue AtomicLValue =
1511 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1512 if (Ty->isAtomicType() ||
1513 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1514 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1518 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1519 if (isNontemporal) {
1520 llvm::MDNode *Node =
1521 llvm::MDNode::get(Store->getContext(),
1522 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1523 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1526 bool MayAlias = BaseInfo.getMayAlias();
1527 llvm::MDNode *TBAA = MayAlias
1528 ? CGM.getTBAAInfo(getContext().CharTy)
1529 : CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo, TBAAOffset);
1531 CGM.DecorateInstructionWithTBAA(Store, TBAA, MayAlias);
1535 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1537 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1538 lvalue.getType(), lvalue.getBaseInfo(),
1539 lvalue.getTBAAInfo(), isInit, lvalue.getTBAABaseType(),
1540 lvalue.getTBAAOffset(), lvalue.isNontemporal());
1543 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1544 /// method emits the address of the lvalue, then loads the result as an rvalue,
1545 /// returning the rvalue.
1546 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1547 if (LV.isObjCWeak()) {
1548 // load of a __weak object.
1549 Address AddrWeakObj = LV.getAddress();
1550 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1553 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1554 // In MRC mode, we do a load+autorelease.
1555 if (!getLangOpts().ObjCAutoRefCount) {
1556 return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1559 // In ARC mode, we load retained and then consume the value.
1560 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
1561 Object = EmitObjCConsumeObject(LV.getType(), Object);
1562 return RValue::get(Object);
1565 if (LV.isSimple()) {
1566 assert(!LV.getType()->isFunctionType());
1568 // Everything needs a load.
1569 return RValue::get(EmitLoadOfScalar(LV, Loc));
1572 if (LV.isVectorElt()) {
1573 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1574 LV.isVolatileQualified());
1575 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1579 // If this is a reference to a subset of the elements of a vector, either
1580 // shuffle the input or extract/insert them as appropriate.
1581 if (LV.isExtVectorElt())
1582 return EmitLoadOfExtVectorElementLValue(LV);
1584 // Global Register variables always invoke intrinsics
1585 if (LV.isGlobalReg())
1586 return EmitLoadOfGlobalRegLValue(LV);
1588 assert(LV.isBitField() && "Unknown LValue type!");
1589 return EmitLoadOfBitfieldLValue(LV, Loc);
1592 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
1593 SourceLocation Loc) {
1594 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1596 // Get the output type.
1597 llvm::Type *ResLTy = ConvertType(LV.getType());
1599 Address Ptr = LV.getBitFieldAddress();
1600 llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1602 if (Info.IsSigned) {
1603 assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1604 unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1606 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1607 if (Info.Offset + HighBits)
1608 Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1611 Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1612 if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1613 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1617 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1618 EmitScalarRangeCheck(Val, LV.getType(), Loc);
1619 return RValue::get(Val);
1622 // If this is a reference to a subset of the elements of a vector, create an
1623 // appropriate shufflevector.
1624 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1625 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1626 LV.isVolatileQualified());
1628 const llvm::Constant *Elts = LV.getExtVectorElts();
1630 // If the result of the expression is a non-vector type, we must be extracting
1631 // a single element. Just codegen as an extractelement.
1632 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1634 unsigned InIdx = getAccessedFieldNo(0, Elts);
1635 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1636 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1639 // Always use shuffle vector to try to retain the original program structure
1640 unsigned NumResultElts = ExprVT->getNumElements();
1642 SmallVector<llvm::Constant*, 4> Mask;
1643 for (unsigned i = 0; i != NumResultElts; ++i)
1644 Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1646 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1647 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1649 return RValue::get(Vec);
1652 /// @brief Generates lvalue for partial ext_vector access.
1653 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
1654 Address VectorAddress = LV.getExtVectorAddress();
1655 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1656 QualType EQT = ExprVT->getElementType();
1657 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1659 Address CastToPointerElement =
1660 Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1661 "conv.ptr.element");
1663 const llvm::Constant *Elts = LV.getExtVectorElts();
1664 unsigned ix = getAccessedFieldNo(0, Elts);
1666 Address VectorBasePtrPlusIx =
1667 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1668 getContext().getTypeSizeInChars(EQT),
1671 return VectorBasePtrPlusIx;
1674 /// @brief Load of global gamed gegisters are always calls to intrinsics.
1675 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
1676 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1677 "Bad type for register variable");
1678 llvm::MDNode *RegName = cast<llvm::MDNode>(
1679 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1681 // We accept integer and pointer types only
1682 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1683 llvm::Type *Ty = OrigTy;
1684 if (OrigTy->isPointerTy())
1685 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1686 llvm::Type *Types[] = { Ty };
1688 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1689 llvm::Value *Call = Builder.CreateCall(
1690 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1691 if (OrigTy->isPointerTy())
1692 Call = Builder.CreateIntToPtr(Call, OrigTy);
1693 return RValue::get(Call);
1697 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1698 /// lvalue, where both are guaranteed to the have the same type, and that type
1700 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
1702 if (!Dst.isSimple()) {
1703 if (Dst.isVectorElt()) {
1704 // Read/modify/write the vector, inserting the new element.
1705 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
1706 Dst.isVolatileQualified());
1707 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1708 Dst.getVectorIdx(), "vecins");
1709 Builder.CreateStore(Vec, Dst.getVectorAddress(),
1710 Dst.isVolatileQualified());
1714 // If this is an update of extended vector elements, insert them as
1716 if (Dst.isExtVectorElt())
1717 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
1719 if (Dst.isGlobalReg())
1720 return EmitStoreThroughGlobalRegLValue(Src, Dst);
1722 assert(Dst.isBitField() && "Unknown LValue type");
1723 return EmitStoreThroughBitfieldLValue(Src, Dst);
1726 // There's special magic for assigning into an ARC-qualified l-value.
1727 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1729 case Qualifiers::OCL_None:
1730 llvm_unreachable("present but none");
1732 case Qualifiers::OCL_ExplicitNone:
1736 case Qualifiers::OCL_Strong:
1738 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1741 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1744 case Qualifiers::OCL_Weak:
1746 // Initialize and then skip the primitive store.
1747 EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1749 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1752 case Qualifiers::OCL_Autoreleasing:
1753 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
1754 Src.getScalarVal()));
1755 // fall into the normal path
1760 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1761 // load of a __weak object.
1762 Address LvalueDst = Dst.getAddress();
1763 llvm::Value *src = Src.getScalarVal();
1764 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1768 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1769 // load of a __strong object.
1770 Address LvalueDst = Dst.getAddress();
1771 llvm::Value *src = Src.getScalarVal();
1772 if (Dst.isObjCIvar()) {
1773 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1774 llvm::Type *ResultType = IntPtrTy;
1775 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
1776 llvm::Value *RHS = dst.getPointer();
1777 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1779 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1780 "sub.ptr.lhs.cast");
1781 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
1782 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1784 } else if (Dst.isGlobalObjCRef()) {
1785 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1786 Dst.isThreadLocalRef());
1789 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1793 assert(Src.isScalar() && "Can't emit an agg store with this method");
1794 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
1797 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
1798 llvm::Value **Result) {
1799 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1800 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1801 Address Ptr = Dst.getBitFieldAddress();
1803 // Get the source value, truncated to the width of the bit-field.
1804 llvm::Value *SrcVal = Src.getScalarVal();
1806 // Cast the source to the storage type and shift it into place.
1807 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
1808 /*IsSigned=*/false);
1809 llvm::Value *MaskedVal = SrcVal;
1811 // See if there are other bits in the bitfield's storage we'll need to load
1812 // and mask together with source before storing.
1813 if (Info.StorageSize != Info.Size) {
1814 assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
1816 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
1818 // Mask the source value as needed.
1819 if (!hasBooleanRepresentation(Dst.getType()))
1820 SrcVal = Builder.CreateAnd(SrcVal,
1821 llvm::APInt::getLowBitsSet(Info.StorageSize,
1826 SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
1828 // Mask out the original value.
1829 Val = Builder.CreateAnd(Val,
1830 ~llvm::APInt::getBitsSet(Info.StorageSize,
1832 Info.Offset + Info.Size),
1835 // Or together the unchanged values and the source value.
1836 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
1838 assert(Info.Offset == 0);
1841 // Write the new value back out.
1842 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
1844 // Return the new value of the bit-field, if requested.
1846 llvm::Value *ResultVal = MaskedVal;
1848 // Sign extend the value if needed.
1849 if (Info.IsSigned) {
1850 assert(Info.Size <= Info.StorageSize);
1851 unsigned HighBits = Info.StorageSize - Info.Size;
1853 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
1854 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
1858 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
1860 *Result = EmitFromMemory(ResultVal, Dst.getType());
1864 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
1866 // This access turns into a read/modify/write of the vector. Load the input
1868 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
1869 Dst.isVolatileQualified());
1870 const llvm::Constant *Elts = Dst.getExtVectorElts();
1872 llvm::Value *SrcVal = Src.getScalarVal();
1874 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
1875 unsigned NumSrcElts = VTy->getNumElements();
1876 unsigned NumDstElts = Vec->getType()->getVectorNumElements();
1877 if (NumDstElts == NumSrcElts) {
1878 // Use shuffle vector is the src and destination are the same number of
1879 // elements and restore the vector mask since it is on the side it will be
1881 SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1882 for (unsigned i = 0; i != NumSrcElts; ++i)
1883 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
1885 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1886 Vec = Builder.CreateShuffleVector(SrcVal,
1887 llvm::UndefValue::get(Vec->getType()),
1889 } else if (NumDstElts > NumSrcElts) {
1890 // Extended the source vector to the same length and then shuffle it
1891 // into the destination.
1892 // FIXME: since we're shuffling with undef, can we just use the indices
1893 // into that? This could be simpler.
1894 SmallVector<llvm::Constant*, 4> ExtMask;
1895 for (unsigned i = 0; i != NumSrcElts; ++i)
1896 ExtMask.push_back(Builder.getInt32(i));
1897 ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
1898 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
1899 llvm::Value *ExtSrcVal =
1900 Builder.CreateShuffleVector(SrcVal,
1901 llvm::UndefValue::get(SrcVal->getType()),
1904 SmallVector<llvm::Constant*, 4> Mask;
1905 for (unsigned i = 0; i != NumDstElts; ++i)
1906 Mask.push_back(Builder.getInt32(i));
1908 // When the vector size is odd and .odd or .hi is used, the last element
1909 // of the Elts constant array will be one past the size of the vector.
1910 // Ignore the last element here, if it is greater than the mask size.
1911 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
1914 // modify when what gets shuffled in
1915 for (unsigned i = 0; i != NumSrcElts; ++i)
1916 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
1917 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1918 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
1920 // We should never shorten the vector
1921 llvm_unreachable("unexpected shorten vector length");
1924 // If the Src is a scalar (not a vector) it must be updating one element.
1925 unsigned InIdx = getAccessedFieldNo(0, Elts);
1926 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1927 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
1930 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
1931 Dst.isVolatileQualified());
1934 /// @brief Store of global named registers are always calls to intrinsics.
1935 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
1936 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
1937 "Bad type for register variable");
1938 llvm::MDNode *RegName = cast<llvm::MDNode>(
1939 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
1940 assert(RegName && "Register LValue is not metadata");
1942 // We accept integer and pointer types only
1943 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
1944 llvm::Type *Ty = OrigTy;
1945 if (OrigTy->isPointerTy())
1946 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1947 llvm::Type *Types[] = { Ty };
1949 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
1950 llvm::Value *Value = Src.getScalarVal();
1951 if (OrigTy->isPointerTy())
1952 Value = Builder.CreatePtrToInt(Value, Ty);
1954 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
1957 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
1958 // generating write-barries API. It is currently a global, ivar,
1960 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1962 bool IsMemberAccess=false) {
1963 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
1966 if (isa<ObjCIvarRefExpr>(E)) {
1967 QualType ExpTy = E->getType();
1968 if (IsMemberAccess && ExpTy->isPointerType()) {
1969 // If ivar is a structure pointer, assigning to field of
1970 // this struct follows gcc's behavior and makes it a non-ivar
1971 // writer-barrier conservatively.
1972 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1973 if (ExpTy->isRecordType()) {
1974 LV.setObjCIvar(false);
1978 LV.setObjCIvar(true);
1979 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
1980 LV.setBaseIvarExp(Exp->getBase());
1981 LV.setObjCArray(E->getType()->isArrayType());
1985 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
1986 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1987 if (VD->hasGlobalStorage()) {
1988 LV.setGlobalObjCRef(true);
1989 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
1992 LV.setObjCArray(E->getType()->isArrayType());
1996 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
1997 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2001 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2002 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2003 if (LV.isObjCIvar()) {
2004 // If cast is to a structure pointer, follow gcc's behavior and make it
2005 // a non-ivar write-barrier.
2006 QualType ExpTy = E->getType();
2007 if (ExpTy->isPointerType())
2008 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2009 if (ExpTy->isRecordType())
2010 LV.setObjCIvar(false);
2015 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2016 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2020 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2021 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2025 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2026 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2030 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2031 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2035 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2036 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2037 if (LV.isObjCIvar() && !LV.isObjCArray())
2038 // Using array syntax to assigning to what an ivar points to is not
2039 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2040 LV.setObjCIvar(false);
2041 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2042 // Using array syntax to assigning to what global points to is not
2043 // same as assigning to the global itself. {id *G;} G[i] = 0;
2044 LV.setGlobalObjCRef(false);
2048 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2049 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2050 // We don't know if member is an 'ivar', but this flag is looked at
2051 // only in the context of LV.isObjCIvar().
2052 LV.setObjCArray(E->getType()->isArrayType());
2057 static llvm::Value *
2058 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
2059 llvm::Value *V, llvm::Type *IRType,
2060 StringRef Name = StringRef()) {
2061 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2062 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2065 static LValue EmitThreadPrivateVarDeclLValue(
2066 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2067 llvm::Type *RealVarTy, SourceLocation Loc) {
2068 Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2069 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2070 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2071 return CGF.MakeAddrLValue(Addr, T, BaseInfo);
2074 Address CodeGenFunction::EmitLoadOfReference(Address Addr,
2075 const ReferenceType *RefTy,
2076 LValueBaseInfo *BaseInfo) {
2077 llvm::Value *Ptr = Builder.CreateLoad(Addr);
2078 return Address(Ptr, getNaturalTypeAlignment(RefTy->getPointeeType(),
2079 BaseInfo, /*forPointee*/ true));
2082 LValue CodeGenFunction::EmitLoadOfReferenceLValue(Address RefAddr,
2083 const ReferenceType *RefTy) {
2084 LValueBaseInfo BaseInfo;
2085 Address Addr = EmitLoadOfReference(RefAddr, RefTy, &BaseInfo);
2086 return MakeAddrLValue(Addr, RefTy->getPointeeType(), BaseInfo);
2089 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2090 const PointerType *PtrTy,
2091 LValueBaseInfo *BaseInfo) {
2092 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2093 return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2095 /*forPointeeType=*/true));
2098 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2099 const PointerType *PtrTy) {
2100 LValueBaseInfo BaseInfo;
2101 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo);
2102 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo);
2105 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2106 const Expr *E, const VarDecl *VD) {
2107 QualType T = E->getType();
2109 // If it's thread_local, emit a call to its wrapper function instead.
2110 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2111 CGF.CGM.getCXXABI().usesThreadWrapperFunction())
2112 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2114 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2115 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2116 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2117 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2118 Address Addr(V, Alignment);
2120 // Emit reference to the private copy of the variable if it is an OpenMP
2121 // threadprivate variable.
2122 if (CGF.getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>())
2123 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2125 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2126 LV = CGF.EmitLoadOfReferenceLValue(Addr, RefTy);
2128 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2129 LV = CGF.MakeAddrLValue(Addr, T, BaseInfo);
2131 setObjCGCLValueClass(CGF.getContext(), E, LV);
2135 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2136 const FunctionDecl *FD) {
2137 if (FD->hasAttr<WeakRefAttr>()) {
2138 ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2139 return aliasee.getPointer();
2142 llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2143 if (!FD->hasPrototype()) {
2144 if (const FunctionProtoType *Proto =
2145 FD->getType()->getAs<FunctionProtoType>()) {
2146 // Ugly case: for a K&R-style definition, the type of the definition
2147 // isn't the same as the type of a use. Correct for this with a
2149 QualType NoProtoType =
2150 CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2151 NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2152 V = llvm::ConstantExpr::getBitCast(V,
2153 CGM.getTypes().ConvertType(NoProtoType));
2159 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
2160 const Expr *E, const FunctionDecl *FD) {
2161 llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2162 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2163 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2164 return CGF.MakeAddrLValue(V, E->getType(), Alignment, BaseInfo);
2167 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2168 llvm::Value *ThisValue) {
2169 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2170 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2171 return CGF.EmitLValueForField(LV, FD);
2174 /// Named Registers are named metadata pointing to the register name
2175 /// which will be read from/written to as an argument to the intrinsic
2176 /// @llvm.read/write_register.
2177 /// So far, only the name is being passed down, but other options such as
2178 /// register type, allocation type or even optimization options could be
2179 /// passed down via the metadata node.
2180 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2181 SmallString<64> Name("llvm.named.register.");
2182 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2183 assert(Asm->getLabel().size() < 64-Name.size() &&
2184 "Register name too big");
2185 Name.append(Asm->getLabel());
2186 llvm::NamedMDNode *M =
2187 CGM.getModule().getOrInsertNamedMetadata(Name);
2188 if (M->getNumOperands() == 0) {
2189 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2191 llvm::Metadata *Ops[] = {Str};
2192 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2195 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2198 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2199 return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2202 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2203 const NamedDecl *ND = E->getDecl();
2204 QualType T = E->getType();
2206 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2207 // Global Named registers access via intrinsics only
2208 if (VD->getStorageClass() == SC_Register &&
2209 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2210 return EmitGlobalNamedRegister(VD, CGM);
2212 // A DeclRefExpr for a reference initialized by a constant expression can
2213 // appear without being odr-used. Directly emit the constant initializer.
2214 const Expr *Init = VD->getAnyInitializer(VD);
2215 if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2216 VD->isUsableInConstantExpressions(getContext()) &&
2217 VD->checkInitIsICE() &&
2218 // Do not emit if it is private OpenMP variable.
2219 !(E->refersToEnclosingVariableOrCapture() && CapturedStmtInfo &&
2220 LocalDeclMap.count(VD))) {
2221 llvm::Constant *Val =
2222 CGM.EmitConstantValue(*VD->evaluateValue(), VD->getType(), this);
2223 assert(Val && "failed to emit reference constant expression");
2224 // FIXME: Eventually we will want to emit vector element references.
2226 // Should we be using the alignment of the constant pointer we emitted?
2227 CharUnits Alignment = getNaturalTypeAlignment(E->getType(), nullptr,
2229 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2230 return MakeAddrLValue(Address(Val, Alignment), T, BaseInfo);
2233 // Check for captured variables.
2234 if (E->refersToEnclosingVariableOrCapture()) {
2235 if (auto *FD = LambdaCaptureFields.lookup(VD))
2236 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2237 else if (CapturedStmtInfo) {
2238 auto I = LocalDeclMap.find(VD);
2239 if (I != LocalDeclMap.end()) {
2240 if (auto RefTy = VD->getType()->getAs<ReferenceType>())
2241 return EmitLoadOfReferenceLValue(I->second, RefTy);
2242 return MakeAddrLValue(I->second, T);
2245 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2246 CapturedStmtInfo->getContextValue());
2247 bool MayAlias = CapLVal.getBaseInfo().getMayAlias();
2248 return MakeAddrLValue(
2249 Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2250 CapLVal.getType(), LValueBaseInfo(AlignmentSource::Decl, MayAlias));
2253 assert(isa<BlockDecl>(CurCodeDecl));
2254 Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
2255 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2256 return MakeAddrLValue(addr, T, BaseInfo);
2260 // FIXME: We should be able to assert this for FunctionDecls as well!
2261 // FIXME: We should be able to assert this for all DeclRefExprs, not just
2262 // those with a valid source location.
2263 assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2264 !E->getLocation().isValid()) &&
2265 "Should not use decl without marking it used!");
2267 if (ND->hasAttr<WeakRefAttr>()) {
2268 const auto *VD = cast<ValueDecl>(ND);
2269 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2270 return MakeAddrLValue(Aliasee, T,
2271 LValueBaseInfo(AlignmentSource::Decl, false));
2274 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2275 // Check if this is a global variable.
2276 if (VD->hasLinkage() || VD->isStaticDataMember())
2277 return EmitGlobalVarDeclLValue(*this, E, VD);
2279 Address addr = Address::invalid();
2281 // The variable should generally be present in the local decl map.
2282 auto iter = LocalDeclMap.find(VD);
2283 if (iter != LocalDeclMap.end()) {
2284 addr = iter->second;
2286 // Otherwise, it might be static local we haven't emitted yet for
2287 // some reason; most likely, because it's in an outer function.
2288 } else if (VD->isStaticLocal()) {
2289 addr = Address(CGM.getOrCreateStaticVarDecl(
2290 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2291 getContext().getDeclAlign(VD));
2293 // No other cases for now.
2295 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2299 // Check for OpenMP threadprivate variables.
2300 if (getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2301 return EmitThreadPrivateVarDeclLValue(
2302 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2306 // Drill into block byref variables.
2307 bool isBlockByref = VD->hasAttr<BlocksAttr>();
2309 addr = emitBlockByrefAddress(addr, VD);
2312 // Drill into reference types.
2314 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2315 LV = EmitLoadOfReferenceLValue(addr, RefTy);
2317 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2318 LV = MakeAddrLValue(addr, T, BaseInfo);
2321 bool isLocalStorage = VD->hasLocalStorage();
2323 bool NonGCable = isLocalStorage &&
2324 !VD->getType()->isReferenceType() &&
2327 LV.getQuals().removeObjCGCAttr();
2331 bool isImpreciseLifetime =
2332 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2333 if (isImpreciseLifetime)
2334 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2335 setObjCGCLValueClass(getContext(), E, LV);
2339 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2340 return EmitFunctionDeclLValue(*this, E, FD);
2342 // FIXME: While we're emitting a binding from an enclosing scope, all other
2343 // DeclRefExprs we see should be implicitly treated as if they also refer to
2344 // an enclosing scope.
2345 if (const auto *BD = dyn_cast<BindingDecl>(ND))
2346 return EmitLValue(BD->getBinding());
2348 llvm_unreachable("Unhandled DeclRefExpr");
2351 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2352 // __extension__ doesn't affect lvalue-ness.
2353 if (E->getOpcode() == UO_Extension)
2354 return EmitLValue(E->getSubExpr());
2356 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2357 switch (E->getOpcode()) {
2358 default: llvm_unreachable("Unknown unary operator lvalue!");
2360 QualType T = E->getSubExpr()->getType()->getPointeeType();
2361 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2363 LValueBaseInfo BaseInfo;
2364 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo);
2365 LValue LV = MakeAddrLValue(Addr, T, BaseInfo);
2366 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2368 // We should not generate __weak write barrier on indirect reference
2369 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2370 // But, we continue to generate __strong write barrier on indirect write
2371 // into a pointer to object.
2372 if (getLangOpts().ObjC1 &&
2373 getLangOpts().getGC() != LangOptions::NonGC &&
2375 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2380 LValue LV = EmitLValue(E->getSubExpr());
2381 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2383 // __real is valid on scalars. This is a faster way of testing that.
2384 // __imag can only produce an rvalue on scalars.
2385 if (E->getOpcode() == UO_Real &&
2386 !LV.getAddress().getElementType()->isStructTy()) {
2387 assert(E->getSubExpr()->getType()->isArithmeticType());
2391 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2394 (E->getOpcode() == UO_Real
2395 ? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
2396 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
2397 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo());
2398 ElemLV.getQuals().addQualifiers(LV.getQuals());
2403 LValue LV = EmitLValue(E->getSubExpr());
2404 bool isInc = E->getOpcode() == UO_PreInc;
2406 if (E->getType()->isAnyComplexType())
2407 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2409 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2415 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2416 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2418 LValueBaseInfo(AlignmentSource::Decl, false));
2421 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2422 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2424 LValueBaseInfo(AlignmentSource::Decl, false));
2427 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2428 auto SL = E->getFunctionName();
2429 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2430 StringRef FnName = CurFn->getName();
2431 if (FnName.startswith("\01"))
2432 FnName = FnName.substr(1);
2433 StringRef NameItems[] = {
2434 PredefinedExpr::getIdentTypeName(E->getIdentType()), FnName};
2435 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2436 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2437 if (auto *BD = dyn_cast<BlockDecl>(CurCodeDecl)) {
2438 std::string Name = SL->getString();
2439 if (!Name.empty()) {
2440 unsigned Discriminator =
2441 CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2443 Name += "_" + Twine(Discriminator + 1).str();
2444 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2445 return MakeAddrLValue(C, E->getType(), BaseInfo);
2447 auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2448 return MakeAddrLValue(C, E->getType(), BaseInfo);
2451 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2452 return MakeAddrLValue(C, E->getType(), BaseInfo);
2455 /// Emit a type description suitable for use by a runtime sanitizer library. The
2456 /// format of a type descriptor is
2459 /// { i16 TypeKind, i16 TypeInfo }
2462 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2463 /// integer, 1 for a floating point value, and -1 for anything else.
2464 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2465 // Only emit each type's descriptor once.
2466 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2469 uint16_t TypeKind = -1;
2470 uint16_t TypeInfo = 0;
2472 if (T->isIntegerType()) {
2474 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2475 (T->isSignedIntegerType() ? 1 : 0);
2476 } else if (T->isFloatingType()) {
2478 TypeInfo = getContext().getTypeSize(T);
2481 // Format the type name as if for a diagnostic, including quotes and
2482 // optionally an 'aka'.
2483 SmallString<32> Buffer;
2484 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
2485 (intptr_t)T.getAsOpaquePtr(),
2486 StringRef(), StringRef(), None, Buffer,
2489 llvm::Constant *Components[] = {
2490 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2491 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2493 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2495 auto *GV = new llvm::GlobalVariable(
2496 CGM.getModule(), Descriptor->getType(),
2497 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2498 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2499 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
2501 // Remember the descriptor for this type.
2502 CGM.setTypeDescriptorInMap(T, GV);
2507 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
2508 llvm::Type *TargetTy = IntPtrTy;
2510 // Floating-point types which fit into intptr_t are bitcast to integers
2511 // and then passed directly (after zero-extension, if necessary).
2512 if (V->getType()->isFloatingPointTy()) {
2513 unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2514 if (Bits <= TargetTy->getIntegerBitWidth())
2515 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2519 // Integers which fit in intptr_t are zero-extended and passed directly.
2520 if (V->getType()->isIntegerTy() &&
2521 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2522 return Builder.CreateZExt(V, TargetTy);
2524 // Pointers are passed directly, everything else is passed by address.
2525 if (!V->getType()->isPointerTy()) {
2526 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2527 Builder.CreateStore(V, Ptr);
2528 V = Ptr.getPointer();
2530 return Builder.CreatePtrToInt(V, TargetTy);
2533 /// \brief Emit a representation of a SourceLocation for passing to a handler
2534 /// in a sanitizer runtime library. The format for this data is:
2536 /// struct SourceLocation {
2537 /// const char *Filename;
2538 /// int32_t Line, Column;
2541 /// For an invalid SourceLocation, the Filename pointer is null.
2542 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
2543 llvm::Constant *Filename;
2546 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
2547 if (PLoc.isValid()) {
2548 StringRef FilenameString = PLoc.getFilename();
2550 int PathComponentsToStrip =
2551 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2552 if (PathComponentsToStrip < 0) {
2553 assert(PathComponentsToStrip != INT_MIN);
2554 int PathComponentsToKeep = -PathComponentsToStrip;
2555 auto I = llvm::sys::path::rbegin(FilenameString);
2556 auto E = llvm::sys::path::rend(FilenameString);
2557 while (I != E && --PathComponentsToKeep)
2560 FilenameString = FilenameString.substr(I - E);
2561 } else if (PathComponentsToStrip > 0) {
2562 auto I = llvm::sys::path::begin(FilenameString);
2563 auto E = llvm::sys::path::end(FilenameString);
2564 while (I != E && PathComponentsToStrip--)
2569 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2571 FilenameString = llvm::sys::path::filename(FilenameString);
2574 auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2575 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
2576 cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2577 Filename = FilenameGV.getPointer();
2578 Line = PLoc.getLine();
2579 Column = PLoc.getColumn();
2581 Filename = llvm::Constant::getNullValue(Int8PtrTy);
2585 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2586 Builder.getInt32(Column)};
2588 return llvm::ConstantStruct::getAnon(Data);
2592 /// \brief Specify under what conditions this check can be recovered
2593 enum class CheckRecoverableKind {
2594 /// Always terminate program execution if this check fails.
2596 /// Check supports recovering, runtime has both fatal (noreturn) and
2597 /// non-fatal handlers for this check.
2599 /// Runtime conditionally aborts, always need to support recovery.
2604 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
2605 assert(llvm::countPopulation(Kind) == 1);
2607 case SanitizerKind::Vptr:
2608 return CheckRecoverableKind::AlwaysRecoverable;
2609 case SanitizerKind::Return:
2610 case SanitizerKind::Unreachable:
2611 return CheckRecoverableKind::Unrecoverable;
2613 return CheckRecoverableKind::Recoverable;
2618 struct SanitizerHandlerInfo {
2619 char const *const Name;
2624 const SanitizerHandlerInfo SanitizerHandlers[] = {
2625 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2626 LIST_SANITIZER_CHECKS
2627 #undef SANITIZER_CHECK
2630 static void emitCheckHandlerCall(CodeGenFunction &CGF,
2631 llvm::FunctionType *FnType,
2632 ArrayRef<llvm::Value *> FnArgs,
2633 SanitizerHandler CheckHandler,
2634 CheckRecoverableKind RecoverKind, bool IsFatal,
2635 llvm::BasicBlock *ContBB) {
2636 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2637 bool NeedsAbortSuffix =
2638 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2639 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2640 const StringRef CheckName = CheckInfo.Name;
2641 std::string FnName =
2642 ("__ubsan_handle_" + CheckName +
2643 (CheckInfo.Version ? "_v" + llvm::utostr(CheckInfo.Version) : "") +
2644 (NeedsAbortSuffix ? "_abort" : ""))
2647 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2649 llvm::AttrBuilder B;
2651 B.addAttribute(llvm::Attribute::NoReturn)
2652 .addAttribute(llvm::Attribute::NoUnwind);
2654 B.addAttribute(llvm::Attribute::UWTable);
2656 llvm::Value *Fn = CGF.CGM.CreateRuntimeFunction(
2658 llvm::AttributeList::get(CGF.getLLVMContext(),
2659 llvm::AttributeList::FunctionIndex, B),
2661 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2663 HandlerCall->setDoesNotReturn();
2664 CGF.Builder.CreateUnreachable();
2666 CGF.Builder.CreateBr(ContBB);
2670 void CodeGenFunction::EmitCheck(
2671 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2672 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
2673 ArrayRef<llvm::Value *> DynamicArgs) {
2674 assert(IsSanitizerScope);
2675 assert(Checked.size() > 0);
2676 assert(CheckHandler >= 0 &&
2677 CheckHandler < sizeof(SanitizerHandlers) / sizeof(*SanitizerHandlers));
2678 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
2680 llvm::Value *FatalCond = nullptr;
2681 llvm::Value *RecoverableCond = nullptr;
2682 llvm::Value *TrapCond = nullptr;
2683 for (int i = 0, n = Checked.size(); i < n; ++i) {
2684 llvm::Value *Check = Checked[i].first;
2685 // -fsanitize-trap= overrides -fsanitize-recover=.
2686 llvm::Value *&Cond =
2687 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2689 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2692 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2696 EmitTrapCheck(TrapCond);
2697 if (!FatalCond && !RecoverableCond)
2700 llvm::Value *JointCond;
2701 if (FatalCond && RecoverableCond)
2702 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2704 JointCond = FatalCond ? FatalCond : RecoverableCond;
2707 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2708 assert(SanOpts.has(Checked[0].second));
2710 for (int i = 1, n = Checked.size(); i < n; ++i) {
2711 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2712 "All recoverable kinds in a single check must be same!");
2713 assert(SanOpts.has(Checked[i].second));
2717 llvm::BasicBlock *Cont = createBasicBlock("cont");
2718 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2719 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2720 // Give hint that we very much don't expect to execute the handler
2721 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2722 llvm::MDBuilder MDHelper(getLLVMContext());
2723 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2724 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2725 EmitBlock(Handlers);
2727 // Handler functions take an i8* pointing to the (handler-specific) static
2728 // information block, followed by a sequence of intptr_t arguments
2729 // representing operand values.
2730 SmallVector<llvm::Value *, 4> Args;
2731 SmallVector<llvm::Type *, 4> ArgTypes;
2732 Args.reserve(DynamicArgs.size() + 1);
2733 ArgTypes.reserve(DynamicArgs.size() + 1);
2735 // Emit handler arguments and create handler function type.
2736 if (!StaticArgs.empty()) {
2737 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2739 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2740 llvm::GlobalVariable::PrivateLinkage, Info);
2741 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2742 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2743 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
2744 ArgTypes.push_back(Int8PtrTy);
2747 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
2748 Args.push_back(EmitCheckValue(DynamicArgs[i]));
2749 ArgTypes.push_back(IntPtrTy);
2752 llvm::FunctionType *FnType =
2753 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
2755 if (!FatalCond || !RecoverableCond) {
2756 // Simple case: we need to generate a single handler call, either
2757 // fatal, or non-fatal.
2758 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
2759 (FatalCond != nullptr), Cont);
2761 // Emit two handler calls: first one for set of unrecoverable checks,
2762 // another one for recoverable.
2763 llvm::BasicBlock *NonFatalHandlerBB =
2764 createBasicBlock("non_fatal." + CheckName);
2765 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
2766 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
2767 EmitBlock(FatalHandlerBB);
2768 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
2770 EmitBlock(NonFatalHandlerBB);
2771 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
2778 void CodeGenFunction::EmitCfiSlowPathCheck(
2779 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
2780 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
2781 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
2783 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
2784 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
2786 llvm::MDBuilder MDHelper(getLLVMContext());
2787 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2788 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
2792 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
2794 llvm::CallInst *CheckCall;
2796 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2798 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2799 llvm::GlobalVariable::PrivateLinkage, Info);
2800 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2801 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2803 llvm::Constant *SlowPathDiagFn = CGM.getModule().getOrInsertFunction(
2804 "__cfi_slowpath_diag",
2805 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
2807 CheckCall = Builder.CreateCall(
2809 {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
2811 llvm::Constant *SlowPathFn = CGM.getModule().getOrInsertFunction(
2813 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
2814 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
2817 CheckCall->setDoesNotThrow();
2822 // Emit a stub for __cfi_check function so that the linker knows about this
2823 // symbol in LTO mode.
2824 void CodeGenFunction::EmitCfiCheckStub() {
2825 llvm::Module *M = &CGM.getModule();
2826 auto &Ctx = M->getContext();
2827 llvm::Function *F = llvm::Function::Create(
2828 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
2829 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
2830 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
2831 // FIXME: consider emitting an intrinsic call like
2832 // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
2833 // which can be lowered in CrossDSOCFI pass to the actual contents of
2834 // __cfi_check. This would allow inlining of __cfi_check calls.
2835 llvm::CallInst::Create(
2836 llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
2837 llvm::ReturnInst::Create(Ctx, nullptr, BB);
2840 // This function is basically a switch over the CFI failure kind, which is
2841 // extracted from CFICheckFailData (1st function argument). Each case is either
2842 // llvm.trap or a call to one of the two runtime handlers, based on
2843 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
2844 // failure kind) traps, but this should really never happen. CFICheckFailData
2845 // can be nullptr if the calling module has -fsanitize-trap behavior for this
2846 // check kind; in this case __cfi_check_fail traps as well.
2847 void CodeGenFunction::EmitCfiCheckFail() {
2848 SanitizerScope SanScope(this);
2849 FunctionArgList Args;
2850 ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy,
2851 ImplicitParamDecl::Other);
2852 ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy,
2853 ImplicitParamDecl::Other);
2854 Args.push_back(&ArgData);
2855 Args.push_back(&ArgAddr);
2857 const CGFunctionInfo &FI =
2858 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
2860 llvm::Function *F = llvm::Function::Create(
2861 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
2862 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
2863 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
2865 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
2869 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
2870 CGM.getContext().VoidPtrTy, ArgData.getLocation());
2872 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
2873 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
2875 // Data == nullptr means the calling module has trap behaviour for this check.
2876 llvm::Value *DataIsNotNullPtr =
2877 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
2878 EmitTrapCheck(DataIsNotNullPtr);
2880 llvm::StructType *SourceLocationTy =
2881 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
2882 llvm::StructType *CfiCheckFailDataTy =
2883 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
2885 llvm::Value *V = Builder.CreateConstGEP2_32(
2887 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
2889 Address CheckKindAddr(V, getIntAlign());
2890 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
2892 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
2893 CGM.getLLVMContext(),
2894 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
2895 llvm::Value *ValidVtable = Builder.CreateZExt(
2896 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
2897 {Addr, AllVtables}),
2900 const std::pair<int, SanitizerMask> CheckKinds[] = {
2901 {CFITCK_VCall, SanitizerKind::CFIVCall},
2902 {CFITCK_NVCall, SanitizerKind::CFINVCall},
2903 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
2904 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
2905 {CFITCK_ICall, SanitizerKind::CFIICall}};
2907 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
2908 for (auto CheckKindMaskPair : CheckKinds) {
2909 int Kind = CheckKindMaskPair.first;
2910 SanitizerMask Mask = CheckKindMaskPair.second;
2912 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
2913 if (CGM.getLangOpts().Sanitize.has(Mask))
2914 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
2915 {Data, Addr, ValidVtable});
2917 EmitTrapCheck(Cond);
2921 // The only reference to this function will be created during LTO link.
2922 // Make sure it survives until then.
2923 CGM.addUsedGlobal(F);
2926 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
2927 llvm::BasicBlock *Cont = createBasicBlock("cont");
2929 // If we're optimizing, collapse all calls to trap down to just one per
2930 // function to save on code size.
2931 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
2932 TrapBB = createBasicBlock("trap");
2933 Builder.CreateCondBr(Checked, Cont, TrapBB);
2935 llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
2936 TrapCall->setDoesNotReturn();
2937 TrapCall->setDoesNotThrow();
2938 Builder.CreateUnreachable();
2940 Builder.CreateCondBr(Checked, Cont, TrapBB);
2946 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
2947 llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
2949 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
2950 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
2951 CGM.getCodeGenOpts().TrapFuncName);
2952 TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
2958 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
2959 LValueBaseInfo *BaseInfo) {
2960 assert(E->getType()->isArrayType() &&
2961 "Array to pointer decay must have array source type!");
2963 // Expressions of array type can't be bitfields or vector elements.
2964 LValue LV = EmitLValue(E);
2965 Address Addr = LV.getAddress();
2966 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
2968 // If the array type was an incomplete type, we need to make sure
2969 // the decay ends up being the right type.
2970 llvm::Type *NewTy = ConvertType(E->getType());
2971 Addr = Builder.CreateElementBitCast(Addr, NewTy);
2973 // Note that VLA pointers are always decayed, so we don't need to do
2975 if (!E->getType()->isVariableArrayType()) {
2976 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
2977 "Expected pointer to array");
2978 Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
2981 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
2982 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
2985 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
2986 /// array to pointer, return the array subexpression.
2987 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
2988 // If this isn't just an array->pointer decay, bail out.
2989 const auto *CE = dyn_cast<CastExpr>(E);
2990 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
2993 // If this is a decay from variable width array, bail out.
2994 const Expr *SubExpr = CE->getSubExpr();
2995 if (SubExpr->getType()->isVariableArrayType())
3001 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
3003 ArrayRef<llvm::Value*> indices,
3006 const llvm::Twine &name = "arrayidx") {
3008 return CGF.EmitCheckedInBoundsGEP(ptr, indices, loc, name);
3010 return CGF.Builder.CreateGEP(ptr, indices, name);
3014 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
3016 CharUnits eltSize) {
3017 // If we have a constant index, we can use the exact offset of the
3018 // element we're accessing.
3019 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3020 CharUnits offset = constantIdx->getZExtValue() * eltSize;
3021 return arrayAlign.alignmentAtOffset(offset);
3023 // Otherwise, use the worst-case alignment for any element.
3025 return arrayAlign.alignmentOfArrayElement(eltSize);
3029 static QualType getFixedSizeElementType(const ASTContext &ctx,
3030 const VariableArrayType *vla) {
3033 eltType = vla->getElementType();
3034 } while ((vla = ctx.getAsVariableArrayType(eltType)));
3038 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
3039 ArrayRef<llvm::Value *> indices,
3040 QualType eltType, bool inbounds,
3042 const llvm::Twine &name = "arrayidx") {
3043 // All the indices except that last must be zero.
3045 for (auto idx : indices.drop_back())
3046 assert(isa<llvm::ConstantInt>(idx) &&
3047 cast<llvm::ConstantInt>(idx)->isZero());
3050 // Determine the element size of the statically-sized base. This is
3051 // the thing that the indices are expressed in terms of.
3052 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3053 eltType = getFixedSizeElementType(CGF.getContext(), vla);
3056 // We can use that to compute the best alignment of the element.
3057 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3058 CharUnits eltAlign =
3059 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3061 llvm::Value *eltPtr =
3062 emitArraySubscriptGEP(CGF, addr.getPointer(), indices, inbounds, loc, name);
3063 return Address(eltPtr, eltAlign);
3066 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3068 // The index must always be an integer, which is not an aggregate. Emit it
3069 // in lexical order (this complexity is, sadly, required by C++17).
3070 llvm::Value *IdxPre =
3071 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3072 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3074 if (E->getLHS() != E->getIdx()) {
3075 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3076 Idx = EmitScalarExpr(E->getIdx());
3079 QualType IdxTy = E->getIdx()->getType();
3080 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3082 if (SanOpts.has(SanitizerKind::ArrayBounds))
3083 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3085 // Extend or truncate the index type to 32 or 64-bits.
3086 if (Promote && Idx->getType() != IntPtrTy)
3087 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3093 // If the base is a vector type, then we are forming a vector element lvalue
3094 // with this subscript.
3095 if (E->getBase()->getType()->isVectorType() &&
3096 !isa<ExtVectorElementExpr>(E->getBase())) {
3097 // Emit the vector as an lvalue to get its address.
3098 LValue LHS = EmitLValue(E->getBase());
3099 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3100 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3101 return LValue::MakeVectorElt(LHS.getAddress(), Idx,
3102 E->getBase()->getType(),
3106 // All the other cases basically behave like simple offsetting.
3108 // Handle the extvector case we ignored above.
3109 if (isa<ExtVectorElementExpr>(E->getBase())) {
3110 LValue LV = EmitLValue(E->getBase());
3111 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3112 Address Addr = EmitExtVectorElementLValue(LV);
3114 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3115 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3117 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo());
3120 LValueBaseInfo BaseInfo;
3121 Address Addr = Address::invalid();
3122 if (const VariableArrayType *vla =
3123 getContext().getAsVariableArrayType(E->getType())) {
3124 // The base must be a pointer, which is not an aggregate. Emit
3125 // it. It needs to be emitted first in case it's what captures
3127 Addr = EmitPointerWithAlignment(E->getBase(), &BaseInfo);
3128 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3130 // The element count here is the total number of non-VLA elements.
3131 llvm::Value *numElements = getVLASize(vla).first;
3133 // Effectively, the multiply by the VLA size is part of the GEP.
3134 // GEP indexes are signed, and scaling an index isn't permitted to
3135 // signed-overflow, so we use the same semantics for our explicit
3136 // multiply. We suppress this if overflow is not undefined behavior.
3137 if (getLangOpts().isSignedOverflowDefined()) {
3138 Idx = Builder.CreateMul(Idx, numElements);
3140 Idx = Builder.CreateNSWMul(Idx, numElements);
3143 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3144 !getLangOpts().isSignedOverflowDefined(),
3147 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3148 // Indexing over an interface, as in "NSString *P; P[4];"
3150 // Emit the base pointer.
3151 Addr = EmitPointerWithAlignment(E->getBase(), &BaseInfo);
3152 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3154 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3155 llvm::Value *InterfaceSizeVal =
3156 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3158 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3160 // We don't necessarily build correct LLVM struct types for ObjC
3161 // interfaces, so we can't rely on GEP to do this scaling
3162 // correctly, so we need to cast to i8*. FIXME: is this actually
3163 // true? A lot of other things in the fragile ABI would break...
3164 llvm::Type *OrigBaseTy = Addr.getType();
3165 Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3168 CharUnits EltAlign =
3169 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3170 llvm::Value *EltPtr = emitArraySubscriptGEP(
3171 *this, Addr.getPointer(), ScaledIdx, false, E->getExprLoc());
3172 Addr = Address(EltPtr, EltAlign);
3175 Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3176 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3177 // If this is A[i] where A is an array, the frontend will have decayed the
3178 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3179 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3180 // "gep x, i" here. Emit one "gep A, 0, i".
3181 assert(Array->getType()->isArrayType() &&
3182 "Array to pointer decay must have array source type!");
3184 // For simple multidimensional array indexing, set the 'accessed' flag for
3185 // better bounds-checking of the base expression.
3186 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3187 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3189 ArrayLV = EmitLValue(Array);
3190 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3192 // Propagate the alignment from the array itself to the result.
3193 Addr = emitArraySubscriptGEP(*this, ArrayLV.getAddress(),
3194 {CGM.getSize(CharUnits::Zero()), Idx},
3196 !getLangOpts().isSignedOverflowDefined(),
3198 BaseInfo = ArrayLV.getBaseInfo();
3200 // The base must be a pointer; emit it with an estimate of its alignment.
3201 Addr = EmitPointerWithAlignment(E->getBase(), &BaseInfo);
3202 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3203 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3204 !getLangOpts().isSignedOverflowDefined(),
3208 LValue LV = MakeAddrLValue(Addr, E->getType(), BaseInfo);
3210 // TODO: Preserve/extend path TBAA metadata?
3212 if (getLangOpts().ObjC1 &&
3213 getLangOpts().getGC() != LangOptions::NonGC) {
3214 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3215 setObjCGCLValueClass(getContext(), E, LV);
3220 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
3221 LValueBaseInfo &BaseInfo,
3222 QualType BaseTy, QualType ElTy,
3223 bool IsLowerBound) {
3225 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3226 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3227 if (BaseTy->isArrayType()) {
3228 Address Addr = BaseLVal.getAddress();
3229 BaseInfo = BaseLVal.getBaseInfo();
3231 // If the array type was an incomplete type, we need to make sure
3232 // the decay ends up being the right type.
3233 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3234 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3236 // Note that VLA pointers are always decayed, so we don't need to do
3238 if (!BaseTy->isVariableArrayType()) {
3239 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3240 "Expected pointer to array");
3241 Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
3245 return CGF.Builder.CreateElementBitCast(Addr,
3246 CGF.ConvertTypeForMem(ElTy));
3248 LValueBaseInfo TypeInfo;
3249 CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeInfo);
3250 BaseInfo.mergeForCast(TypeInfo);
3251 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3253 return CGF.EmitPointerWithAlignment(Base, &BaseInfo);
3256 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3257 bool IsLowerBound) {
3260 dyn_cast<OMPArraySectionExpr>(E->getBase()->IgnoreParenImpCasts()))
3261 BaseTy = OMPArraySectionExpr::getBaseOriginalType(ASE);
3263 BaseTy = E->getBase()->getType();
3264 QualType ResultExprTy;
3265 if (auto *AT = getContext().getAsArrayType(BaseTy))
3266 ResultExprTy = AT->getElementType();
3268 ResultExprTy = BaseTy->getPointeeType();
3269 llvm::Value *Idx = nullptr;
3270 if (IsLowerBound || E->getColonLoc().isInvalid()) {
3271 // Requesting lower bound or upper bound, but without provided length and
3272 // without ':' symbol for the default length -> length = 1.
3273 // Idx = LowerBound ?: 0;
3274 if (auto *LowerBound = E->getLowerBound()) {
3275 Idx = Builder.CreateIntCast(
3276 EmitScalarExpr(LowerBound), IntPtrTy,
3277 LowerBound->getType()->hasSignedIntegerRepresentation());
3279 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3281 // Try to emit length or lower bound as constant. If this is possible, 1
3282 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3283 // IR (LB + Len) - 1.
3284 auto &C = CGM.getContext();
3285 auto *Length = E->getLength();
3286 llvm::APSInt ConstLength;
3288 // Idx = LowerBound + Length - 1;
3289 if (Length->isIntegerConstantExpr(ConstLength, C)) {
3290 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3293 auto *LowerBound = E->getLowerBound();
3294 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3295 if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3296 ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3297 LowerBound = nullptr;
3301 else if (!LowerBound)
3304 if (Length || LowerBound) {
3305 auto *LowerBoundVal =
3307 ? Builder.CreateIntCast(
3308 EmitScalarExpr(LowerBound), IntPtrTy,
3309 LowerBound->getType()->hasSignedIntegerRepresentation())
3310 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3313 ? Builder.CreateIntCast(
3314 EmitScalarExpr(Length), IntPtrTy,
3315 Length->getType()->hasSignedIntegerRepresentation())
3316 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3317 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3319 !getLangOpts().isSignedOverflowDefined());
3320 if (Length && LowerBound) {
3321 Idx = Builder.CreateSub(
3322 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3323 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3326 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3328 // Idx = ArraySize - 1;
3329 QualType ArrayTy = BaseTy->isPointerType()
3330 ? E->getBase()->IgnoreParenImpCasts()->getType()
3332 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3333 Length = VAT->getSizeExpr();
3334 if (Length->isIntegerConstantExpr(ConstLength, C))
3337 auto *CAT = C.getAsConstantArrayType(ArrayTy);
3338 ConstLength = CAT->getSize();
3341 auto *LengthVal = Builder.CreateIntCast(
3342 EmitScalarExpr(Length), IntPtrTy,
3343 Length->getType()->hasSignedIntegerRepresentation());
3344 Idx = Builder.CreateSub(
3345 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3346 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3348 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3350 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3356 Address EltPtr = Address::invalid();
3357 LValueBaseInfo BaseInfo;
3358 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3359 // The base must be a pointer, which is not an aggregate. Emit
3360 // it. It needs to be emitted first in case it's what captures
3363 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, BaseTy,
3364 VLA->getElementType(), IsLowerBound);
3365 // The element count here is the total number of non-VLA elements.
3366 llvm::Value *NumElements = getVLASize(VLA).first;
3368 // Effectively, the multiply by the VLA size is part of the GEP.
3369 // GEP indexes are signed, and scaling an index isn't permitted to
3370 // signed-overflow, so we use the same semantics for our explicit
3371 // multiply. We suppress this if overflow is not undefined behavior.
3372 if (getLangOpts().isSignedOverflowDefined())
3373 Idx = Builder.CreateMul(Idx, NumElements);
3375 Idx = Builder.CreateNSWMul(Idx, NumElements);
3376 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3377 !getLangOpts().isSignedOverflowDefined(),
3379 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3380 // If this is A[i] where A is an array, the frontend will have decayed the
3381 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3382 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3383 // "gep x, i" here. Emit one "gep A, 0, i".
3384 assert(Array->getType()->isArrayType() &&
3385 "Array to pointer decay must have array source type!");
3387 // For simple multidimensional array indexing, set the 'accessed' flag for
3388 // better bounds-checking of the base expression.
3389 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3390 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3392 ArrayLV = EmitLValue(Array);
3394 // Propagate the alignment from the array itself to the result.
3395 EltPtr = emitArraySubscriptGEP(
3396 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3397 ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3399 BaseInfo = ArrayLV.getBaseInfo();
3401 Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3402 BaseTy, ResultExprTy, IsLowerBound);
3403 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3404 !getLangOpts().isSignedOverflowDefined(),
3408 return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo);
3411 LValue CodeGenFunction::
3412 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
3413 // Emit the base vector as an l-value.
3416 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3418 // If it is a pointer to a vector, emit the address and form an lvalue with
3420 LValueBaseInfo BaseInfo;
3421 Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo);
3422 const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3423 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo);
3424 Base.getQuals().removeObjCGCAttr();
3425 } else if (E->getBase()->isGLValue()) {
3426 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3427 // emit the base as an lvalue.
3428 assert(E->getBase()->getType()->isVectorType());
3429 Base = EmitLValue(E->getBase());
3431 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3432 assert(E->getBase()->getType()->isVectorType() &&
3433 "Result must be a vector");
3434 llvm::Value *Vec = EmitScalarExpr(E->getBase());
3436 // Store the vector to memory (because LValue wants an address).
3437 Address VecMem = CreateMemTemp(E->getBase()->getType());
3438 Builder.CreateStore(Vec, VecMem);
3439 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3440 LValueBaseInfo(AlignmentSource::Decl, false));
3444 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
3446 // Encode the element access list into a vector of unsigned indices.
3447 SmallVector<uint32_t, 4> Indices;
3448 E->getEncodedElementAccess(Indices);
3450 if (Base.isSimple()) {
3451 llvm::Constant *CV =
3452 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3453 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3454 Base.getBaseInfo());
3456 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3458 llvm::Constant *BaseElts = Base.getExtVectorElts();
3459 SmallVector<llvm::Constant *, 4> CElts;
3461 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3462 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3463 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3464 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
3465 Base.getBaseInfo());
3468 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
3469 Expr *BaseExpr = E->getBase();
3470 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3473 LValueBaseInfo BaseInfo;
3474 Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo);
3475 QualType PtrTy = BaseExpr->getType()->getPointeeType();
3476 SanitizerSet SkippedChecks;
3477 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3479 SkippedChecks.set(SanitizerKind::Alignment, true);
3480 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3481 SkippedChecks.set(SanitizerKind::Null, true);
3482 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3483 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3484 BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo);
3486 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3488 NamedDecl *ND = E->getMemberDecl();
3489 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3490 LValue LV = EmitLValueForField(BaseLV, Field);
3491 setObjCGCLValueClass(getContext(), E, LV);
3495 if (auto *VD = dyn_cast<VarDecl>(ND))
3496 return EmitGlobalVarDeclLValue(*this, E, VD);
3498 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3499 return EmitFunctionDeclLValue(*this, E, FD);
3501 llvm_unreachable("Unhandled member declaration!");
3504 /// Given that we are currently emitting a lambda, emit an l-value for
3505 /// one of its members.
3506 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
3507 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3508 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3509 QualType LambdaTagType =
3510 getContext().getTagDeclType(Field->getParent());
3511 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3512 return EmitLValueForField(LambdaLV, Field);
3515 /// Drill down to the storage of a field without walking into
3516 /// reference types.
3518 /// The resulting address doesn't necessarily have the right type.
3519 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
3520 const FieldDecl *field) {
3521 const RecordDecl *rec = field->getParent();
3524 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3527 // Adjust the alignment down to the given offset.
3528 // As a special case, if the LLVM field index is 0, we know that this
3530 assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
3531 .getFieldOffset(field->getFieldIndex()) == 0) &&
3532 "LLVM field at index zero had non-zero offset?");
3534 auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
3535 auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
3536 offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
3539 return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
3542 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3543 const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3547 if (RD->isDynamicClass())
3550 for (const auto &Base : RD->bases())
3551 if (hasAnyVptr(Base.getType(), Context))
3554 for (const FieldDecl *Field : RD->fields())
3555 if (hasAnyVptr(Field->getType(), Context))
3561 LValue CodeGenFunction::EmitLValueForField(LValue base,
3562 const FieldDecl *field) {
3563 LValueBaseInfo BaseInfo = base.getBaseInfo();
3564 AlignmentSource fieldAlignSource =
3565 getFieldAlignmentSource(BaseInfo.getAlignmentSource());
3566 LValueBaseInfo FieldBaseInfo(fieldAlignSource, BaseInfo.getMayAlias());
3568 const RecordDecl *rec = field->getParent();
3569 if (rec->isUnion() || rec->hasAttr<MayAliasAttr>())
3570 FieldBaseInfo.setMayAlias(true);
3571 bool mayAlias = FieldBaseInfo.getMayAlias();
3573 if (field->isBitField()) {
3574 const CGRecordLayout &RL =
3575 CGM.getTypes().getCGRecordLayout(field->getParent());
3576 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3577 Address Addr = base.getAddress();
3578 unsigned Idx = RL.getLLVMFieldNo(field);
3580 // For structs, we GEP to the field that the record layout suggests.
3581 Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
3583 // Get the access type.
3584 llvm::Type *FieldIntTy =
3585 llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3586 if (Addr.getElementType() != FieldIntTy)
3587 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3589 QualType fieldType =
3590 field->getType().withCVRQualifiers(base.getVRQualifiers());
3591 return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo);
3594 QualType type = field->getType();
3595 Address addr = base.getAddress();
3596 unsigned cvr = base.getVRQualifiers();
3597 bool TBAAPath = CGM.getCodeGenOpts().StructPathTBAA;
3598 if (rec->isUnion()) {
3599 // For unions, there is no pointer adjustment.
3600 assert(!type->isReferenceType() && "union has reference member");
3601 // TODO: handle path-aware TBAA for union.
3604 const auto FieldType = field->getType();
3605 if (CGM.getCodeGenOpts().StrictVTablePointers &&
3606 hasAnyVptr(FieldType, getContext()))
3607 // Because unions can easily skip invariant.barriers, we need to add
3608 // a barrier every time CXXRecord field with vptr is referenced.
3609 addr = Address(Builder.CreateInvariantGroupBarrier(addr.getPointer()),
3610 addr.getAlignment());
3612 // For structs, we GEP to the field that the record layout suggests.
3613 addr = emitAddrOfFieldStorage(*this, addr, field);
3615 // If this is a reference field, load the reference right now.
3616 if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
3617 llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
3618 if (cvr & Qualifiers::Volatile) load->setVolatile(true);
3620 // Loading the reference will disable path-aware TBAA.
3622 if (CGM.shouldUseTBAA()) {
3625 tbaa = CGM.getTBAAInfo(getContext().CharTy);
3627 tbaa = CGM.getTBAAInfo(type);
3629 CGM.DecorateInstructionWithTBAA(load, tbaa);
3633 type = refType->getPointeeType();
3635 CharUnits alignment =
3636 getNaturalTypeAlignment(type, &FieldBaseInfo, /*pointee*/ true);
3637 FieldBaseInfo.setMayAlias(false);
3638 addr = Address(load, alignment);
3640 // Qualifiers on the struct don't apply to the referencee, and
3641 // we'll pick up CVR from the actual type later, so reset these
3642 // additional qualifiers now.
3647 // Make sure that the address is pointing to the right type. This is critical
3648 // for both unions and structs. A union needs a bitcast, a struct element
3649 // will need a bitcast if the LLVM type laid out doesn't match the desired
3651 addr = Builder.CreateElementBitCast(addr,
3652 CGM.getTypes().ConvertTypeForMem(type),
3655 if (field->hasAttr<AnnotateAttr>())
3656 addr = EmitFieldAnnotations(field, addr);
3658 LValue LV = MakeAddrLValue(addr, type, FieldBaseInfo);
3659 LV.getQuals().addCVRQualifiers(cvr);
3661 const ASTRecordLayout &Layout =
3662 getContext().getASTRecordLayout(field->getParent());
3663 // Set the base type to be the base type of the base LValue and
3664 // update offset to be relative to the base type.
3665 LV.setTBAABaseType(mayAlias ? getContext().CharTy : base.getTBAABaseType());
3666 LV.setTBAAOffset(mayAlias ? 0 : base.getTBAAOffset() +
3667 Layout.getFieldOffset(field->getFieldIndex()) /
3668 getContext().getCharWidth());
3671 // __weak attribute on a field is ignored.
3672 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3673 LV.getQuals().removeObjCGCAttr();
3675 // Fields of may_alias structs act like 'char' for TBAA purposes.
3676 // FIXME: this should get propagated down through anonymous structs
3678 if (mayAlias && LV.getTBAAInfo())
3679 LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
3685 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
3686 const FieldDecl *Field) {
3687 QualType FieldType = Field->getType();
3689 if (!FieldType->isReferenceType())
3690 return EmitLValueForField(Base, Field);
3692 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3694 // Make sure that the address is pointing to the right type.
3695 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3696 V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3698 // TODO: access-path TBAA?
3699 LValueBaseInfo BaseInfo = Base.getBaseInfo();
3700 LValueBaseInfo FieldBaseInfo(
3701 getFieldAlignmentSource(BaseInfo.getAlignmentSource()),
3702 BaseInfo.getMayAlias());
3703 return MakeAddrLValue(V, FieldType, FieldBaseInfo);
3706 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
3707 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
3708 if (E->isFileScope()) {
3709 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
3710 return MakeAddrLValue(GlobalPtr, E->getType(), BaseInfo);
3712 if (E->getType()->isVariablyModifiedType())
3713 // make sure to emit the VLA size.
3714 EmitVariablyModifiedType(E->getType());
3716 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
3717 const Expr *InitExpr = E->getInitializer();
3718 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), BaseInfo);
3720 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
3726 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
3727 if (!E->isGLValue())
3728 // Initializing an aggregate temporary in C++11: T{...}.
3729 return EmitAggExprToLValue(E);
3731 // An lvalue initializer list must be initializing a reference.
3732 assert(E->isTransparent() && "non-transparent glvalue init list");
3733 return EmitLValue(E->getInit(0));
3736 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
3737 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
3738 /// LValue is returned and the current block has been terminated.
3739 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
3740 const Expr *Operand) {
3741 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
3742 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
3746 return CGF.EmitLValue(Operand);
3749 LValue CodeGenFunction::
3750 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
3751 if (!expr->isGLValue()) {
3752 // ?: here should be an aggregate.
3753 assert(hasAggregateEvaluationKind(expr->getType()) &&
3754 "Unexpected conditional operator!");
3755 return EmitAggExprToLValue(expr);
3758 OpaqueValueMapping binding(*this, expr);
3760 const Expr *condExpr = expr->getCond();
3762 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
3763 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
3764 if (!CondExprBool) std::swap(live, dead);
3766 if (!ContainsLabel(dead)) {
3767 // If the true case is live, we need to track its region.
3769 incrementProfileCounter(expr);
3770 return EmitLValue(live);
3774 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
3775 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
3776 llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
3778 ConditionalEvaluation eval(*this);
3779 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
3781 // Any temporaries created here are conditional.
3782 EmitBlock(lhsBlock);
3783 incrementProfileCounter(expr);
3785 Optional<LValue> lhs =
3786 EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
3789 if (lhs && !lhs->isSimple())
3790 return EmitUnsupportedLValue(expr, "conditional operator");
3792 lhsBlock = Builder.GetInsertBlock();
3794 Builder.CreateBr(contBlock);
3796 // Any temporaries created here are conditional.
3797 EmitBlock(rhsBlock);
3799 Optional<LValue> rhs =
3800 EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
3802 if (rhs && !rhs->isSimple())
3803 return EmitUnsupportedLValue(expr, "conditional operator");
3804 rhsBlock = Builder.GetInsertBlock();
3806 EmitBlock(contBlock);
3809 llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
3811 phi->addIncoming(lhs->getPointer(), lhsBlock);
3812 phi->addIncoming(rhs->getPointer(), rhsBlock);
3813 Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
3814 AlignmentSource alignSource =
3815 std::max(lhs->getBaseInfo().getAlignmentSource(),
3816 rhs->getBaseInfo().getAlignmentSource());
3817 bool MayAlias = lhs->getBaseInfo().getMayAlias() ||
3818 rhs->getBaseInfo().getMayAlias();
3819 return MakeAddrLValue(result, expr->getType(),
3820 LValueBaseInfo(alignSource, MayAlias));
3822 assert((lhs || rhs) &&
3823 "both operands of glvalue conditional are throw-expressions?");
3824 return lhs ? *lhs : *rhs;
3828 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
3829 /// type. If the cast is to a reference, we can have the usual lvalue result,
3830 /// otherwise if a cast is needed by the code generator in an lvalue context,
3831 /// then it must mean that we need the address of an aggregate in order to
3832 /// access one of its members. This can happen for all the reasons that casts
3833 /// are permitted with aggregate result, including noop aggregate casts, and
3834 /// cast from scalar to union.
3835 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
3836 switch (E->getCastKind()) {
3839 case CK_ArrayToPointerDecay:
3840 case CK_FunctionToPointerDecay:
3841 case CK_NullToMemberPointer:
3842 case CK_NullToPointer:
3843 case CK_IntegralToPointer:
3844 case CK_PointerToIntegral:
3845 case CK_PointerToBoolean:
3846 case CK_VectorSplat:
3847 case CK_IntegralCast:
3848 case CK_BooleanToSignedIntegral:
3849 case CK_IntegralToBoolean:
3850 case CK_IntegralToFloating:
3851 case CK_FloatingToIntegral:
3852 case CK_FloatingToBoolean:
3853 case CK_FloatingCast:
3854 case CK_FloatingRealToComplex:
3855 case CK_FloatingComplexToReal:
3856 case CK_FloatingComplexToBoolean:
3857 case CK_FloatingComplexCast:
3858 case CK_FloatingComplexToIntegralComplex:
3859 case CK_IntegralRealToComplex:
3860 case CK_IntegralComplexToReal:
3861 case CK_IntegralComplexToBoolean:
3862 case CK_IntegralComplexCast:
3863 case CK_IntegralComplexToFloatingComplex:
3864 case CK_DerivedToBaseMemberPointer:
3865 case CK_BaseToDerivedMemberPointer:
3866 case CK_MemberPointerToBoolean:
3867 case CK_ReinterpretMemberPointer:
3868 case CK_AnyPointerToBlockPointerCast:
3869 case CK_ARCProduceObject:
3870 case CK_ARCConsumeObject:
3871 case CK_ARCReclaimReturnedObject:
3872 case CK_ARCExtendBlockObject:
3873 case CK_CopyAndAutoreleaseBlockObject:
3874 case CK_AddressSpaceConversion:
3875 case CK_IntToOCLSampler:
3876 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
3879 llvm_unreachable("dependent cast kind in IR gen!");
3881 case CK_BuiltinFnToFnPtr:
3882 llvm_unreachable("builtin functions are handled elsewhere");
3884 // These are never l-values; just use the aggregate emission code.
3885 case CK_NonAtomicToAtomic:
3886 case CK_AtomicToNonAtomic:
3887 return EmitAggExprToLValue(E);
3890 LValue LV = EmitLValue(E->getSubExpr());
3891 Address V = LV.getAddress();
3892 const auto *DCE = cast<CXXDynamicCastExpr>(E);
3893 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
3896 case CK_ConstructorConversion:
3897 case CK_UserDefinedConversion:
3898 case CK_CPointerToObjCPointerCast:
3899 case CK_BlockPointerToObjCPointerCast:
3901 case CK_LValueToRValue:
3902 return EmitLValue(E->getSubExpr());
3904 case CK_UncheckedDerivedToBase:
3905 case CK_DerivedToBase: {
3906 const RecordType *DerivedClassTy =
3907 E->getSubExpr()->getType()->getAs<RecordType>();
3908 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3910 LValue LV = EmitLValue(E->getSubExpr());
3911 Address This = LV.getAddress();
3913 // Perform the derived-to-base conversion
3914 Address Base = GetAddressOfBaseClass(
3915 This, DerivedClassDecl, E->path_begin(), E->path_end(),
3916 /*NullCheckValue=*/false, E->getExprLoc());
3918 return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo());
3921 return EmitAggExprToLValue(E);
3922 case CK_BaseToDerived: {
3923 const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
3924 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3926 LValue LV = EmitLValue(E->getSubExpr());
3928 // Perform the base-to-derived conversion
3930 GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
3931 E->path_begin(), E->path_end(),
3932 /*NullCheckValue=*/false);
3934 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
3935 // performed and the object is not of the derived type.
3936 if (sanitizePerformTypeCheck())
3937 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
3938 Derived.getPointer(), E->getType());
3940 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
3941 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
3942 /*MayBeNull=*/false,
3943 CFITCK_DerivedCast, E->getLocStart());
3945 return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo());
3947 case CK_LValueBitCast: {
3948 // This must be a reinterpret_cast (or c-style equivalent).
3949 const auto *CE = cast<ExplicitCastExpr>(E);
3951 CGM.EmitExplicitCastExprType(CE, this);
3952 LValue LV = EmitLValue(E->getSubExpr());
3953 Address V = Builder.CreateBitCast(LV.getAddress(),
3954 ConvertType(CE->getTypeAsWritten()));
3956 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
3957 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
3958 /*MayBeNull=*/false,
3959 CFITCK_UnrelatedCast, E->getLocStart());
3961 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo());
3963 case CK_ObjCObjectLValueCast: {
3964 LValue LV = EmitLValue(E->getSubExpr());
3965 Address V = Builder.CreateElementBitCast(LV.getAddress(),
3966 ConvertType(E->getType()));
3967 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo());
3969 case CK_ZeroToOCLQueue:
3970 llvm_unreachable("NULL to OpenCL queue lvalue cast is not valid");
3971 case CK_ZeroToOCLEvent:
3972 llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
3975 llvm_unreachable("Unhandled lvalue cast kind?");
3978 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
3979 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
3980 return getOpaqueLValueMapping(e);
3983 RValue CodeGenFunction::EmitRValueForField(LValue LV,
3984 const FieldDecl *FD,
3985 SourceLocation Loc) {
3986 QualType FT = FD->getType();
3987 LValue FieldLV = EmitLValueForField(LV, FD);
3988 switch (getEvaluationKind(FT)) {
3990 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
3992 return FieldLV.asAggregateRValue();
3994 // This routine is used to load fields one-by-one to perform a copy, so
3995 // don't load reference fields.
3996 if (FD->getType()->isReferenceType())
3997 return RValue::get(FieldLV.getPointer());
3998 return EmitLoadOfLValue(FieldLV, Loc);
4000 llvm_unreachable("bad evaluation kind");
4003 //===--------------------------------------------------------------------===//
4004 // Expression Emission
4005 //===--------------------------------------------------------------------===//
4007 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
4008 ReturnValueSlot ReturnValue) {
4009 // Builtins never have block type.
4010 if (E->getCallee()->getType()->isBlockPointerType())
4011 return EmitBlockCallExpr(E, ReturnValue);
4013 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4014 return EmitCXXMemberCallExpr(CE, ReturnValue);
4016 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4017 return EmitCUDAKernelCallExpr(CE, ReturnValue);
4019 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4020 if (const CXXMethodDecl *MD =
4021 dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4022 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4024 CGCallee callee = EmitCallee(E->getCallee());
4026 if (callee.isBuiltin()) {
4027 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4031 if (callee.isPseudoDestructor()) {
4032 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
4035 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4038 /// Emit a CallExpr without considering whether it might be a subclass.
4039 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
4040 ReturnValueSlot ReturnValue) {
4041 CGCallee Callee = EmitCallee(E->getCallee());
4042 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4045 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
4046 if (auto builtinID = FD->getBuiltinID()) {
4047 return CGCallee::forBuiltin(builtinID, FD);
4050 llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4051 return CGCallee::forDirect(calleePtr, FD);
4054 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
4055 E = E->IgnoreParens();
4057 // Look through function-to-pointer decay.
4058 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4059 if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4060 ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4061 return EmitCallee(ICE->getSubExpr());
4064 // Resolve direct calls.
4065 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4066 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4067 return EmitDirectCallee(*this, FD);
4069 } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4070 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4071 EmitIgnoredExpr(ME->getBase());
4072 return EmitDirectCallee(*this, FD);
4075 // Look through template substitutions.
4076 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4077 return EmitCallee(NTTP->getReplacement());
4079 // Treat pseudo-destructor calls differently.
4080 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4081 return CGCallee::forPseudoDestructor(PDE);
4084 // Otherwise, we have an indirect reference.
4085 llvm::Value *calleePtr;
4086 QualType functionType;
4087 if (auto ptrType = E->getType()->getAs<PointerType>()) {
4088 calleePtr = EmitScalarExpr(E);
4089 functionType = ptrType->getPointeeType();
4091 functionType = E->getType();
4092 calleePtr = EmitLValue(E).getPointer();
4094 assert(functionType->isFunctionType());
4095 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(),
4096 E->getReferencedDeclOfCallee());
4097 CGCallee callee(calleeInfo, calleePtr);
4101 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
4102 // Comma expressions just emit their LHS then their RHS as an l-value.
4103 if (E->getOpcode() == BO_Comma) {
4104 EmitIgnoredExpr(E->getLHS());
4105 EnsureInsertPoint();
4106 return EmitLValue(E->getRHS());
4109 if (E->getOpcode() == BO_PtrMemD ||
4110 E->getOpcode() == BO_PtrMemI)
4111 return EmitPointerToDataMemberBinaryExpr(E);
4113 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4115 // Note that in all of these cases, __block variables need the RHS
4116 // evaluated first just in case the variable gets moved by the RHS.
4118 switch (getEvaluationKind(E->getType())) {
4120 switch (E->getLHS()->getType().getObjCLifetime()) {
4121 case Qualifiers::OCL_Strong:
4122 return EmitARCStoreStrong(E, /*ignored*/ false).first;
4124 case Qualifiers::OCL_Autoreleasing:
4125 return EmitARCStoreAutoreleasing(E).first;
4127 // No reason to do any of these differently.
4128 case Qualifiers::OCL_None:
4129 case Qualifiers::OCL_ExplicitNone:
4130 case Qualifiers::OCL_Weak:
4134 RValue RV = EmitAnyExpr(E->getRHS());
4135 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
4137 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
4138 EmitStoreThroughLValue(RV, LV);
4143 return EmitComplexAssignmentLValue(E);
4146 return EmitAggExprToLValue(E);
4148 llvm_unreachable("bad evaluation kind");
4151 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
4152 RValue RV = EmitCallExpr(E);
4155 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4156 LValueBaseInfo(AlignmentSource::Decl, false));
4158 assert(E->getCallReturnType(getContext())->isReferenceType() &&
4159 "Can't have a scalar return unless the return type is a "
4162 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4165 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
4166 // FIXME: This shouldn't require another copy.
4167 return EmitAggExprToLValue(E);
4170 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
4171 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
4172 && "binding l-value to type which needs a temporary");
4173 AggValueSlot Slot = CreateAggTemp(E->getType());
4174 EmitCXXConstructExpr(E, Slot);
4175 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4176 LValueBaseInfo(AlignmentSource::Decl, false));
4180 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
4181 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
4184 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
4185 return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
4186 ConvertType(E->getType()));
4189 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
4190 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4191 LValueBaseInfo(AlignmentSource::Decl, false));
4195 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
4196 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4197 Slot.setExternallyDestructed();
4198 EmitAggExpr(E->getSubExpr(), Slot);
4199 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4200 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4201 LValueBaseInfo(AlignmentSource::Decl, false));
4205 CodeGenFunction::EmitLambdaLValue(const LambdaExpr *E) {
4206 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4207 EmitLambdaExpr(E, Slot);
4208 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4209 LValueBaseInfo(AlignmentSource::Decl, false));
4212 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
4213 RValue RV = EmitObjCMessageExpr(E);
4216 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4217 LValueBaseInfo(AlignmentSource::Decl, false));
4219 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4220 "Can't have a scalar return unless the return type is a "
4223 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4226 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
4228 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
4229 return MakeAddrLValue(V, E->getType(),
4230 LValueBaseInfo(AlignmentSource::Decl, false));
4233 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
4234 const ObjCIvarDecl *Ivar) {
4235 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4238 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
4239 llvm::Value *BaseValue,
4240 const ObjCIvarDecl *Ivar,
4241 unsigned CVRQualifiers) {
4242 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4243 Ivar, CVRQualifiers);
4246 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
4247 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4248 llvm::Value *BaseValue = nullptr;
4249 const Expr *BaseExpr = E->getBase();
4250 Qualifiers BaseQuals;
4253 BaseValue = EmitScalarExpr(BaseExpr);
4254 ObjectTy = BaseExpr->getType()->getPointeeType();
4255 BaseQuals = ObjectTy.getQualifiers();
4257 LValue BaseLV = EmitLValue(BaseExpr);
4258 BaseValue = BaseLV.getPointer();
4259 ObjectTy = BaseExpr->getType();
4260 BaseQuals = ObjectTy.getQualifiers();
4264 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4265 BaseQuals.getCVRQualifiers());
4266 setObjCGCLValueClass(getContext(), E, LV);
4270 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
4271 // Can only get l-value for message expression returning aggregate type
4272 RValue RV = EmitAnyExprToTemp(E);
4273 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4274 LValueBaseInfo(AlignmentSource::Decl, false));
4277 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4278 const CallExpr *E, ReturnValueSlot ReturnValue,
4279 llvm::Value *Chain) {
4280 // Get the actual function type. The callee type will always be a pointer to
4281 // function type or a block pointer type.
4282 assert(CalleeType->isFunctionPointerType() &&
4283 "Call must have function pointer type!");
4285 const Decl *TargetDecl = OrigCallee.getAbstractInfo().getCalleeDecl();
4287 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
4288 // We can only guarantee that a function is called from the correct
4289 // context/function based on the appropriate target attributes,
4290 // so only check in the case where we have both always_inline and target
4291 // since otherwise we could be making a conditional call after a check for
4292 // the proper cpu features (and it won't cause code generation issues due to
4293 // function based code generation).
4294 if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
4295 TargetDecl->hasAttr<TargetAttr>())
4296 checkTargetFeatures(E, FD);
4298 CalleeType = getContext().getCanonicalType(CalleeType);
4300 const auto *FnType =
4301 cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
4303 CGCallee Callee = OrigCallee;
4305 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4306 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4307 if (llvm::Constant *PrefixSig =
4308 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
4309 SanitizerScope SanScope(this);
4310 llvm::Constant *FTRTTIConst =
4311 CGM.GetAddrOfRTTIDescriptor(QualType(FnType, 0), /*ForEH=*/true);
4312 llvm::Type *PrefixStructTyElems[] = {
4313 PrefixSig->getType(),
4314 FTRTTIConst->getType()
4316 llvm::StructType *PrefixStructTy = llvm::StructType::get(
4317 CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4319 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4321 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4322 CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4323 llvm::Value *CalleeSigPtr =
4324 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4325 llvm::Value *CalleeSig =
4326 Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4327 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4329 llvm::BasicBlock *Cont = createBasicBlock("cont");
4330 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4331 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4333 EmitBlock(TypeCheck);
4334 llvm::Value *CalleeRTTIPtr =
4335 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4336 llvm::Value *CalleeRTTI =
4337 Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4338 llvm::Value *CalleeRTTIMatch =
4339 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4340 llvm::Constant *StaticData[] = {
4341 EmitCheckSourceLocation(E->getLocStart()),
4342 EmitCheckTypeDescriptor(CalleeType)
4344 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4345 SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
4347 Builder.CreateBr(Cont);
4352 // If we are checking indirect calls and this call is indirect, check that the
4353 // function pointer is a member of the bit set for the function type.
4354 if (SanOpts.has(SanitizerKind::CFIICall) &&
4355 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4356 SanitizerScope SanScope(this);
4357 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4359 llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4360 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4362 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4363 llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4364 llvm::Value *TypeTest = Builder.CreateCall(
4365 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4367 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4368 llvm::Constant *StaticData[] = {
4369 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4370 EmitCheckSourceLocation(E->getLocStart()),
4371 EmitCheckTypeDescriptor(QualType(FnType, 0)),
4373 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4374 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4375 CastedCallee, StaticData);
4377 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4378 SanitizerHandler::CFICheckFail, StaticData,
4379 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4385 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
4386 CGM.getContext().VoidPtrTy);
4388 // C++17 requires that we evaluate arguments to a call using assignment syntax
4389 // right-to-left, and that we evaluate arguments to certain other operators
4390 // left-to-right. Note that we allow this to override the order dictated by
4391 // the calling convention on the MS ABI, which means that parameter
4392 // destruction order is not necessarily reverse construction order.
4393 // FIXME: Revisit this based on C++ committee response to unimplementability.
4394 EvaluationOrder Order = EvaluationOrder::Default;
4395 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4396 if (OCE->isAssignmentOp())
4397 Order = EvaluationOrder::ForceRightToLeft;
4399 switch (OCE->getOperator()) {
4401 case OO_GreaterGreater:
4406 Order = EvaluationOrder::ForceLeftToRight;
4414 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4415 E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4417 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
4418 Args, FnType, /*isChainCall=*/Chain);
4421 // If the expression that denotes the called function has a type
4422 // that does not include a prototype, [the default argument
4423 // promotions are performed]. If the number of arguments does not
4424 // equal the number of parameters, the behavior is undefined. If
4425 // the function is defined with a type that includes a prototype,
4426 // and either the prototype ends with an ellipsis (, ...) or the
4427 // types of the arguments after promotion are not compatible with
4428 // the types of the parameters, the behavior is undefined. If the
4429 // function is defined with a type that does not include a
4430 // prototype, and the types of the arguments after promotion are
4431 // not compatible with those of the parameters after promotion,
4432 // the behavior is undefined [except in some trivial cases].
4433 // That is, in the general case, we should assume that a call
4434 // through an unprototyped function type works like a *non-variadic*
4435 // call. The way we make this work is to cast to the exact type
4436 // of the promoted arguments.
4438 // Chain calls use this same code path to add the invisible chain parameter
4439 // to the function type.
4440 if (isa<FunctionNoProtoType>(FnType) || Chain) {
4441 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4442 CalleeTy = CalleeTy->getPointerTo();
4444 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4445 CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
4446 Callee.setFunctionPointer(CalleePtr);
4449 return EmitCall(FnInfo, Callee, ReturnValue, Args);
4452 LValue CodeGenFunction::
4453 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
4454 Address BaseAddr = Address::invalid();
4455 if (E->getOpcode() == BO_PtrMemI) {
4456 BaseAddr = EmitPointerWithAlignment(E->getLHS());
4458 BaseAddr = EmitLValue(E->getLHS()).getAddress();
4461 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4463 const MemberPointerType *MPT
4464 = E->getRHS()->getType()->getAs<MemberPointerType>();
4466 LValueBaseInfo BaseInfo;
4467 Address MemberAddr =
4468 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo);
4470 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo);
4473 /// Given the address of a temporary variable, produce an r-value of
4475 RValue CodeGenFunction::convertTempToRValue(Address addr,
4477 SourceLocation loc) {
4478 LValue lvalue = MakeAddrLValue(addr, type,
4479 LValueBaseInfo(AlignmentSource::Decl, false));
4480 switch (getEvaluationKind(type)) {
4482 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4484 return lvalue.asAggregateRValue();
4486 return RValue::get(EmitLoadOfScalar(lvalue, loc));
4488 llvm_unreachable("bad evaluation kind");
4491 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4492 assert(Val->getType()->isFPOrFPVectorTy());
4493 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4496 llvm::MDBuilder MDHelper(getLLVMContext());
4497 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
4499 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
4503 struct LValueOrRValue {
4509 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
4510 const PseudoObjectExpr *E,
4512 AggValueSlot slot) {
4513 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
4515 // Find the result expression, if any.
4516 const Expr *resultExpr = E->getResultExpr();
4517 LValueOrRValue result;
4519 for (PseudoObjectExpr::const_semantics_iterator
4520 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
4521 const Expr *semantic = *i;
4523 // If this semantic expression is an opaque value, bind it
4524 // to the result of its source expression.
4525 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
4527 // If this is the result expression, we may need to evaluate
4528 // directly into the slot.
4529 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
4531 if (ov == resultExpr && ov->isRValue() && !forLValue &&
4532 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
4533 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
4534 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
4535 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
4537 opaqueData = OVMA::bind(CGF, ov, LV);
4538 result.RV = slot.asRValue();
4540 // Otherwise, emit as normal.
4542 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
4544 // If this is the result, also evaluate the result now.
4545 if (ov == resultExpr) {
4547 result.LV = CGF.EmitLValue(ov);
4549 result.RV = CGF.EmitAnyExpr(ov, slot);
4553 opaques.push_back(opaqueData);
4555 // Otherwise, if the expression is the result, evaluate it
4556 // and remember the result.
4557 } else if (semantic == resultExpr) {
4559 result.LV = CGF.EmitLValue(semantic);
4561 result.RV = CGF.EmitAnyExpr(semantic, slot);
4563 // Otherwise, evaluate the expression in an ignored context.
4565 CGF.EmitIgnoredExpr(semantic);
4569 // Unbind all the opaques now.
4570 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
4571 opaques[i].unbind(CGF);
4576 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
4577 AggValueSlot slot) {
4578 return emitPseudoObjectExpr(*this, E, false, slot).RV;
4581 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
4582 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;