1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This contains code to emit Expr nodes as LLVM code.
11 //===----------------------------------------------------------------------===//
15 #include "CGCleanup.h"
16 #include "CGDebugInfo.h"
17 #include "CGObjCRuntime.h"
18 #include "CGOpenMPRuntime.h"
19 #include "CGRecordLayout.h"
20 #include "CodeGenFunction.h"
21 #include "CodeGenModule.h"
22 #include "ConstantEmitter.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/Basic/Builtins.h"
29 #include "clang/Basic/CodeGenOptions.h"
30 #include "llvm/ADT/Hashing.h"
31 #include "llvm/ADT/StringExtras.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/Intrinsics.h"
34 #include "llvm/IR/LLVMContext.h"
35 #include "llvm/IR/MDBuilder.h"
36 #include "llvm/Support/ConvertUTF.h"
37 #include "llvm/Support/MathExtras.h"
38 #include "llvm/Support/Path.h"
39 #include "llvm/Transforms/Utils/SanitizerStats.h"
43 using namespace clang;
44 using namespace CodeGen;
46 //===--------------------------------------------------------------------===//
47 // Miscellaneous Helper Methods
48 //===--------------------------------------------------------------------===//
50 llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
51 unsigned addressSpace =
52 cast<llvm::PointerType>(value->getType())->getAddressSpace();
54 llvm::PointerType *destType = Int8PtrTy;
56 destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
58 if (value->getType() == destType) return value;
59 return Builder.CreateBitCast(value, destType);
62 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
64 Address CodeGenFunction::CreateTempAllocaWithoutCast(llvm::Type *Ty,
67 llvm::Value *ArraySize) {
68 auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
69 Alloca->setAlignment(Align.getQuantity());
70 return Address(Alloca, Align);
73 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
74 /// block. The alloca is casted to default address space if necessary.
75 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
77 llvm::Value *ArraySize,
78 Address *AllocaAddr) {
79 auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
82 llvm::Value *V = Alloca.getPointer();
83 // Alloca always returns a pointer in alloca address space, which may
84 // be different from the type defined by the language. For example,
85 // in C++ the auto variables are in the default address space. Therefore
86 // cast alloca to the default address space when necessary.
87 if (getASTAllocaAddressSpace() != LangAS::Default) {
88 auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
89 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
90 // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
91 // otherwise alloca is inserted at the current insertion point of the
94 Builder.SetInsertPoint(AllocaInsertPt);
95 V = getTargetHooks().performAddrSpaceCast(
96 *this, V, getASTAllocaAddressSpace(), LangAS::Default,
97 Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
100 return Address(V, Align);
103 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
104 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
105 /// insertion point of the builder.
106 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
108 llvm::Value *ArraySize) {
110 return Builder.CreateAlloca(Ty, ArraySize, Name);
111 return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
112 ArraySize, Name, AllocaInsertPt);
115 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
116 /// default alignment of the corresponding LLVM type, which is *not*
117 /// guaranteed to be related in any way to the expected alignment of
118 /// an AST type that might have been lowered to Ty.
119 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
122 CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
123 return CreateTempAlloca(Ty, Align, Name);
126 void CodeGenFunction::InitTempAlloca(Address Var, llvm::Value *Init) {
127 assert(isa<llvm::AllocaInst>(Var.getPointer()));
128 auto *Store = new llvm::StoreInst(Init, Var.getPointer());
129 Store->setAlignment(Var.getAlignment().getQuantity());
130 llvm::BasicBlock *Block = AllocaInsertPt->getParent();
131 Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
134 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
135 CharUnits Align = getContext().getTypeAlignInChars(Ty);
136 return CreateTempAlloca(ConvertType(Ty), Align, Name);
139 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name,
141 // FIXME: Should we prefer the preferred type alignment here?
142 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
145 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
146 const Twine &Name, Address *Alloca) {
147 return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
148 /*ArraySize=*/nullptr, Alloca);
151 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty, CharUnits Align,
153 return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
156 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty,
158 return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
162 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
163 /// expression and compare the result against zero, returning an Int1Ty value.
164 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
165 PGO.setCurrentStmt(E);
166 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
167 llvm::Value *MemPtr = EmitScalarExpr(E);
168 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
171 QualType BoolTy = getContext().BoolTy;
172 SourceLocation Loc = E->getExprLoc();
173 if (!E->getType()->isAnyComplexType())
174 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
176 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
180 /// EmitIgnoredExpr - Emit code to compute the specified expression,
181 /// ignoring the result.
182 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
184 return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
186 // Just emit it as an l-value and drop the result.
190 /// EmitAnyExpr - Emit code to compute the specified expression which
191 /// can have any type. The result is returned as an RValue struct.
192 /// If this is an aggregate expression, AggSlot indicates where the
193 /// result should be returned.
194 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
195 AggValueSlot aggSlot,
197 switch (getEvaluationKind(E->getType())) {
199 return RValue::get(EmitScalarExpr(E, ignoreResult));
201 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
203 if (!ignoreResult && aggSlot.isIgnored())
204 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
205 EmitAggExpr(E, aggSlot);
206 return aggSlot.asRValue();
208 llvm_unreachable("bad evaluation kind");
211 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
212 /// always be accessible even if no aggregate location is provided.
213 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
214 AggValueSlot AggSlot = AggValueSlot::ignored();
216 if (hasAggregateEvaluationKind(E->getType()))
217 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
218 return EmitAnyExpr(E, AggSlot);
221 /// EmitAnyExprToMem - Evaluate an expression into a given memory
223 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
227 // FIXME: This function should take an LValue as an argument.
228 switch (getEvaluationKind(E->getType())) {
230 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
234 case TEK_Aggregate: {
235 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
236 AggValueSlot::IsDestructed_t(IsInit),
237 AggValueSlot::DoesNotNeedGCBarriers,
238 AggValueSlot::IsAliased_t(!IsInit),
239 AggValueSlot::MayOverlap));
244 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
245 LValue LV = MakeAddrLValue(Location, E->getType());
246 EmitStoreThroughLValue(RV, LV);
250 llvm_unreachable("bad evaluation kind");
254 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
255 const Expr *E, Address ReferenceTemporary) {
256 // Objective-C++ ARC:
257 // If we are binding a reference to a temporary that has ownership, we
258 // need to perform retain/release operations on the temporary.
260 // FIXME: This should be looking at E, not M.
261 if (auto Lifetime = M->getType().getObjCLifetime()) {
263 case Qualifiers::OCL_None:
264 case Qualifiers::OCL_ExplicitNone:
265 // Carry on to normal cleanup handling.
268 case Qualifiers::OCL_Autoreleasing:
269 // Nothing to do; cleaned up by an autorelease pool.
272 case Qualifiers::OCL_Strong:
273 case Qualifiers::OCL_Weak:
274 switch (StorageDuration Duration = M->getStorageDuration()) {
276 // Note: we intentionally do not register a cleanup to release
277 // the object on program termination.
281 // FIXME: We should probably register a cleanup in this case.
285 case SD_FullExpression:
286 CodeGenFunction::Destroyer *Destroy;
287 CleanupKind CleanupKind;
288 if (Lifetime == Qualifiers::OCL_Strong) {
289 const ValueDecl *VD = M->getExtendingDecl();
291 VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
292 CleanupKind = CGF.getARCCleanupKind();
293 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
294 : &CodeGenFunction::destroyARCStrongImprecise;
296 // __weak objects always get EH cleanups; otherwise, exceptions
297 // could cause really nasty crashes instead of mere leaks.
298 CleanupKind = NormalAndEHCleanup;
299 Destroy = &CodeGenFunction::destroyARCWeak;
301 if (Duration == SD_FullExpression)
302 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
303 M->getType(), *Destroy,
304 CleanupKind & EHCleanup);
306 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
308 *Destroy, CleanupKind & EHCleanup);
312 llvm_unreachable("temporary cannot have dynamic storage duration");
314 llvm_unreachable("unknown storage duration");
318 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
319 if (const RecordType *RT =
320 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
321 // Get the destructor for the reference temporary.
322 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
323 if (!ClassDecl->hasTrivialDestructor())
324 ReferenceTemporaryDtor = ClassDecl->getDestructor();
327 if (!ReferenceTemporaryDtor)
330 // Call the destructor for the temporary.
331 switch (M->getStorageDuration()) {
334 llvm::FunctionCallee CleanupFn;
335 llvm::Constant *CleanupArg;
336 if (E->getType()->isArrayType()) {
337 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
338 ReferenceTemporary, E->getType(),
339 CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
340 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
341 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
343 CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
344 GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
345 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
347 CGF.CGM.getCXXABI().registerGlobalDtor(
348 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
352 case SD_FullExpression:
353 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
354 CodeGenFunction::destroyCXXObject,
355 CGF.getLangOpts().Exceptions);
359 CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
360 ReferenceTemporary, E->getType(),
361 CodeGenFunction::destroyCXXObject,
362 CGF.getLangOpts().Exceptions);
366 llvm_unreachable("temporary cannot have dynamic storage duration");
370 static Address createReferenceTemporary(CodeGenFunction &CGF,
371 const MaterializeTemporaryExpr *M,
373 Address *Alloca = nullptr) {
374 auto &TCG = CGF.getTargetHooks();
375 switch (M->getStorageDuration()) {
376 case SD_FullExpression:
378 // If we have a constant temporary array or record try to promote it into a
379 // constant global under the same rules a normal constant would've been
380 // promoted. This is easier on the optimizer and generally emits fewer
382 QualType Ty = Inner->getType();
383 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
384 (Ty->isArrayType() || Ty->isRecordType()) &&
385 CGF.CGM.isTypeConstant(Ty, true))
386 if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
387 if (auto AddrSpace = CGF.getTarget().getConstantAddressSpace()) {
388 auto AS = AddrSpace.getValue();
389 auto *GV = new llvm::GlobalVariable(
390 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
391 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
392 llvm::GlobalValue::NotThreadLocal,
393 CGF.getContext().getTargetAddressSpace(AS));
394 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
395 GV->setAlignment(alignment.getQuantity());
396 llvm::Constant *C = GV;
397 if (AS != LangAS::Default)
398 C = TCG.performAddrSpaceCast(
399 CGF.CGM, GV, AS, LangAS::Default,
400 GV->getValueType()->getPointerTo(
401 CGF.getContext().getTargetAddressSpace(LangAS::Default)));
402 // FIXME: Should we put the new global into a COMDAT?
403 return Address(C, alignment);
406 return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
410 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
413 llvm_unreachable("temporary can't have dynamic storage duration");
415 llvm_unreachable("unknown storage duration");
418 LValue CodeGenFunction::
419 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
420 const Expr *E = M->GetTemporaryExpr();
422 assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
423 !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
424 "Reference should never be pseudo-strong!");
426 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
427 // as that will cause the lifetime adjustment to be lost for ARC
428 auto ownership = M->getType().getObjCLifetime();
429 if (ownership != Qualifiers::OCL_None &&
430 ownership != Qualifiers::OCL_ExplicitNone) {
431 Address Object = createReferenceTemporary(*this, M, E);
432 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
433 Object = Address(llvm::ConstantExpr::getBitCast(Var,
434 ConvertTypeForMem(E->getType())
435 ->getPointerTo(Object.getAddressSpace())),
436 Object.getAlignment());
438 // createReferenceTemporary will promote the temporary to a global with a
439 // constant initializer if it can. It can only do this to a value of
440 // ARC-manageable type if the value is global and therefore "immune" to
441 // ref-counting operations. Therefore we have no need to emit either a
442 // dynamic initialization or a cleanup and we can just return the address
444 if (Var->hasInitializer())
445 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
447 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
449 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
450 AlignmentSource::Decl);
452 switch (getEvaluationKind(E->getType())) {
453 default: llvm_unreachable("expected scalar or aggregate expression");
455 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
457 case TEK_Aggregate: {
458 EmitAggExpr(E, AggValueSlot::forAddr(Object,
459 E->getType().getQualifiers(),
460 AggValueSlot::IsDestructed,
461 AggValueSlot::DoesNotNeedGCBarriers,
462 AggValueSlot::IsNotAliased,
463 AggValueSlot::DoesNotOverlap));
468 pushTemporaryCleanup(*this, M, E, Object);
472 SmallVector<const Expr *, 2> CommaLHSs;
473 SmallVector<SubobjectAdjustment, 2> Adjustments;
474 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
476 for (const auto &Ignored : CommaLHSs)
477 EmitIgnoredExpr(Ignored);
479 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
480 if (opaque->getType()->isRecordType()) {
481 assert(Adjustments.empty());
482 return EmitOpaqueValueLValue(opaque);
486 // Create and initialize the reference temporary.
487 Address Alloca = Address::invalid();
488 Address Object = createReferenceTemporary(*this, M, E, &Alloca);
489 if (auto *Var = dyn_cast<llvm::GlobalVariable>(
490 Object.getPointer()->stripPointerCasts())) {
491 Object = Address(llvm::ConstantExpr::getBitCast(
492 cast<llvm::Constant>(Object.getPointer()),
493 ConvertTypeForMem(E->getType())->getPointerTo()),
494 Object.getAlignment());
495 // If the temporary is a global and has a constant initializer or is a
496 // constant temporary that we promoted to a global, we may have already
498 if (!Var->hasInitializer()) {
499 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
500 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
503 switch (M->getStorageDuration()) {
505 if (auto *Size = EmitLifetimeStart(
506 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
507 Alloca.getPointer())) {
508 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
513 case SD_FullExpression: {
514 if (!ShouldEmitLifetimeMarkers)
517 // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
518 // marker. Instead, start the lifetime of a conditional temporary earlier
519 // so that it's unconditional. Don't do this in ASan's use-after-scope
520 // mode so that it gets the more precise lifetime marks. If the type has
521 // a non-trivial destructor, we'll have a cleanup block for it anyway,
522 // so this typically doesn't help; skip it in that case.
523 ConditionalEvaluation *OldConditional = nullptr;
524 CGBuilderTy::InsertPoint OldIP;
525 if (isInConditionalBranch() && !E->getType().isDestructedType() &&
526 !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) {
527 OldConditional = OutermostConditional;
528 OutermostConditional = nullptr;
530 OldIP = Builder.saveIP();
531 llvm::BasicBlock *Block = OldConditional->getStartingBlock();
532 Builder.restoreIP(CGBuilderTy::InsertPoint(
533 Block, llvm::BasicBlock::iterator(Block->back())));
536 if (auto *Size = EmitLifetimeStart(
537 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
538 Alloca.getPointer())) {
539 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
543 if (OldConditional) {
544 OutermostConditional = OldConditional;
545 Builder.restoreIP(OldIP);
553 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
555 pushTemporaryCleanup(*this, M, E, Object);
557 // Perform derived-to-base casts and/or field accesses, to get from the
558 // temporary object we created (and, potentially, for which we extended
559 // the lifetime) to the subobject we're binding the reference to.
560 for (unsigned I = Adjustments.size(); I != 0; --I) {
561 SubobjectAdjustment &Adjustment = Adjustments[I-1];
562 switch (Adjustment.Kind) {
563 case SubobjectAdjustment::DerivedToBaseAdjustment:
565 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
566 Adjustment.DerivedToBase.BasePath->path_begin(),
567 Adjustment.DerivedToBase.BasePath->path_end(),
568 /*NullCheckValue=*/ false, E->getExprLoc());
571 case SubobjectAdjustment::FieldAdjustment: {
572 LValue LV = MakeAddrLValue(Object, E->getType(), AlignmentSource::Decl);
573 LV = EmitLValueForField(LV, Adjustment.Field);
574 assert(LV.isSimple() &&
575 "materialized temporary field is not a simple lvalue");
576 Object = LV.getAddress();
580 case SubobjectAdjustment::MemberPointerAdjustment: {
581 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
582 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
589 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
593 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
594 // Emit the expression as an lvalue.
595 LValue LV = EmitLValue(E);
596 assert(LV.isSimple());
597 llvm::Value *Value = LV.getPointer();
599 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
600 // C++11 [dcl.ref]p5 (as amended by core issue 453):
601 // If a glvalue to which a reference is directly bound designates neither
602 // an existing object or function of an appropriate type nor a region of
603 // storage of suitable size and alignment to contain an object of the
604 // reference's type, the behavior is undefined.
605 QualType Ty = E->getType();
606 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
609 return RValue::get(Value);
613 /// getAccessedFieldNo - Given an encoded value and a result number, return the
614 /// input field number being accessed.
615 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
616 const llvm::Constant *Elts) {
617 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
621 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
622 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
624 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
625 llvm::Value *K47 = Builder.getInt64(47);
626 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
627 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
628 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
629 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
630 return Builder.CreateMul(B1, KMul);
633 bool CodeGenFunction::isNullPointerAllowed(TypeCheckKind TCK) {
634 return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
635 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation;
638 bool CodeGenFunction::isVptrCheckRequired(TypeCheckKind TCK, QualType Ty) {
639 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
640 return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
641 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
642 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
643 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation);
646 bool CodeGenFunction::sanitizePerformTypeCheck() const {
647 return SanOpts.has(SanitizerKind::Null) |
648 SanOpts.has(SanitizerKind::Alignment) |
649 SanOpts.has(SanitizerKind::ObjectSize) |
650 SanOpts.has(SanitizerKind::Vptr);
653 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
654 llvm::Value *Ptr, QualType Ty,
656 SanitizerSet SkippedChecks,
657 llvm::Value *ArraySize) {
658 if (!sanitizePerformTypeCheck())
661 // Don't check pointers outside the default address space. The null check
662 // isn't correct, the object-size check isn't supported by LLVM, and we can't
663 // communicate the addresses to the runtime handler for the vptr check.
664 if (Ptr->getType()->getPointerAddressSpace())
667 // Don't check pointers to volatile data. The behavior here is implementation-
669 if (Ty.isVolatileQualified())
672 SanitizerScope SanScope(this);
674 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
675 llvm::BasicBlock *Done = nullptr;
677 // Quickly determine whether we have a pointer to an alloca. It's possible
678 // to skip null checks, and some alignment checks, for these pointers. This
679 // can reduce compile-time significantly.
681 dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
683 llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
684 llvm::Value *IsNonNull = nullptr;
685 bool IsGuaranteedNonNull =
686 SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
687 bool AllowNullPointers = isNullPointerAllowed(TCK);
688 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
689 !IsGuaranteedNonNull) {
690 // The glvalue must not be an empty glvalue.
691 IsNonNull = Builder.CreateIsNotNull(Ptr);
693 // The IR builder can constant-fold the null check if the pointer points to
695 IsGuaranteedNonNull = IsNonNull == True;
697 // Skip the null check if the pointer is known to be non-null.
698 if (!IsGuaranteedNonNull) {
699 if (AllowNullPointers) {
700 // When performing pointer casts, it's OK if the value is null.
701 // Skip the remaining checks in that case.
702 Done = createBasicBlock("null");
703 llvm::BasicBlock *Rest = createBasicBlock("not.null");
704 Builder.CreateCondBr(IsNonNull, Rest, Done);
707 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
712 if (SanOpts.has(SanitizerKind::ObjectSize) &&
713 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
714 !Ty->isIncompleteType()) {
715 uint64_t TySize = getContext().getTypeSizeInChars(Ty).getQuantity();
716 llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
718 Size = Builder.CreateMul(Size, ArraySize);
720 // Degenerate case: new X[0] does not need an objectsize check.
721 llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
722 if (!ConstantSize || !ConstantSize->isNullValue()) {
723 // The glvalue must refer to a large enough storage region.
724 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
726 // FIXME: Get object address space
727 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
728 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
729 llvm::Value *Min = Builder.getFalse();
730 llvm::Value *NullIsUnknown = Builder.getFalse();
731 llvm::Value *Dynamic = Builder.getFalse();
732 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
733 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
734 Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown, Dynamic}), Size);
735 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
739 uint64_t AlignVal = 0;
740 llvm::Value *PtrAsInt = nullptr;
742 if (SanOpts.has(SanitizerKind::Alignment) &&
743 !SkippedChecks.has(SanitizerKind::Alignment)) {
744 AlignVal = Alignment.getQuantity();
745 if (!Ty->isIncompleteType() && !AlignVal)
746 AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
748 // The glvalue must be suitably aligned.
750 (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
751 PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
752 llvm::Value *Align = Builder.CreateAnd(
753 PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
754 llvm::Value *Aligned =
755 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
757 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
761 if (Checks.size() > 0) {
762 // Make sure we're not losing information. Alignment needs to be a power of
764 assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
765 llvm::Constant *StaticData[] = {
766 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
767 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
768 llvm::ConstantInt::get(Int8Ty, TCK)};
769 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
770 PtrAsInt ? PtrAsInt : Ptr);
773 // If possible, check that the vptr indicates that there is a subobject of
774 // type Ty at offset zero within this object.
776 // C++11 [basic.life]p5,6:
777 // [For storage which does not refer to an object within its lifetime]
778 // The program has undefined behavior if:
779 // -- the [pointer or glvalue] is used to access a non-static data member
780 // or call a non-static member function
781 if (SanOpts.has(SanitizerKind::Vptr) &&
782 !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
783 // Ensure that the pointer is non-null before loading it. If there is no
784 // compile-time guarantee, reuse the run-time null check or emit a new one.
785 if (!IsGuaranteedNonNull) {
787 IsNonNull = Builder.CreateIsNotNull(Ptr);
789 Done = createBasicBlock("vptr.null");
790 llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
791 Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
792 EmitBlock(VptrNotNull);
795 // Compute a hash of the mangled name of the type.
797 // FIXME: This is not guaranteed to be deterministic! Move to a
798 // fingerprinting mechanism once LLVM provides one. For the time
799 // being the implementation happens to be deterministic.
800 SmallString<64> MangledName;
801 llvm::raw_svector_ostream Out(MangledName);
802 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
805 // Blacklist based on the mangled type.
806 if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
807 SanitizerKind::Vptr, Out.str())) {
808 llvm::hash_code TypeHash = hash_value(Out.str());
810 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
811 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
812 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
813 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
814 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
815 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
817 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
818 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
820 // Look the hash up in our cache.
821 const int CacheSize = 128;
822 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
823 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
824 "__ubsan_vptr_type_cache");
825 llvm::Value *Slot = Builder.CreateAnd(Hash,
826 llvm::ConstantInt::get(IntPtrTy,
828 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
829 llvm::Value *CacheVal =
830 Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
833 // If the hash isn't in the cache, call a runtime handler to perform the
834 // hard work of checking whether the vptr is for an object of the right
835 // type. This will either fill in the cache and return, or produce a
837 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
838 llvm::Constant *StaticData[] = {
839 EmitCheckSourceLocation(Loc),
840 EmitCheckTypeDescriptor(Ty),
841 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
842 llvm::ConstantInt::get(Int8Ty, TCK)
844 llvm::Value *DynamicData[] = { Ptr, Hash };
845 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
846 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
852 Builder.CreateBr(Done);
857 /// Determine whether this expression refers to a flexible array member in a
858 /// struct. We disable array bounds checks for such members.
859 static bool isFlexibleArrayMemberExpr(const Expr *E) {
860 // For compatibility with existing code, we treat arrays of length 0 or
861 // 1 as flexible array members.
862 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
863 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
864 if (CAT->getSize().ugt(1))
866 } else if (!isa<IncompleteArrayType>(AT))
869 E = E->IgnoreParens();
871 // A flexible array member must be the last member in the class.
872 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
873 // FIXME: If the base type of the member expr is not FD->getParent(),
874 // this should not be treated as a flexible array member access.
875 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
876 RecordDecl::field_iterator FI(
877 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
878 return ++FI == FD->getParent()->field_end();
880 } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
881 return IRE->getDecl()->getNextIvar() == nullptr;
887 llvm::Value *CodeGenFunction::LoadPassedObjectSize(const Expr *E,
889 ASTContext &C = getContext();
890 uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
894 auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
898 auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
902 auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
906 // Don't load the size if it's a lower bound.
907 int POSType = POSAttr->getType();
908 if (POSType != 0 && POSType != 1)
911 // Find the implicit size parameter.
912 auto PassedSizeIt = SizeArguments.find(ParamDecl);
913 if (PassedSizeIt == SizeArguments.end())
916 const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
917 assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
918 Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
919 llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
920 C.getSizeType(), E->getExprLoc());
921 llvm::Value *SizeOfElement =
922 llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
923 return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
926 /// If Base is known to point to the start of an array, return the length of
927 /// that array. Return 0 if the length cannot be determined.
928 static llvm::Value *getArrayIndexingBound(
929 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
930 // For the vector indexing extension, the bound is the number of elements.
931 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
932 IndexedType = Base->getType();
933 return CGF.Builder.getInt32(VT->getNumElements());
936 Base = Base->IgnoreParens();
938 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
939 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
940 !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
941 IndexedType = CE->getSubExpr()->getType();
942 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
943 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
944 return CGF.Builder.getInt(CAT->getSize());
945 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
946 return CGF.getVLASize(VAT).NumElts;
947 // Ignore pass_object_size here. It's not applicable on decayed pointers.
951 QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
952 if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
953 IndexedType = Base->getType();
960 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
961 llvm::Value *Index, QualType IndexType,
963 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
964 "should not be called unless adding bounds checks");
965 SanitizerScope SanScope(this);
967 QualType IndexedType;
968 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
972 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
973 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
974 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
976 llvm::Constant *StaticData[] = {
977 EmitCheckSourceLocation(E->getExprLoc()),
978 EmitCheckTypeDescriptor(IndexedType),
979 EmitCheckTypeDescriptor(IndexType)
981 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
982 : Builder.CreateICmpULE(IndexVal, BoundVal);
983 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
984 SanitizerHandler::OutOfBounds, StaticData, Index);
988 CodeGenFunction::ComplexPairTy CodeGenFunction::
989 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
990 bool isInc, bool isPre) {
991 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
993 llvm::Value *NextVal;
994 if (isa<llvm::IntegerType>(InVal.first->getType())) {
995 uint64_t AmountVal = isInc ? 1 : -1;
996 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
998 // Add the inc/dec to the real part.
999 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1001 QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
1002 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1005 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1007 // Add the inc/dec to the real part.
1008 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1011 ComplexPairTy IncVal(NextVal, InVal.second);
1013 // Store the updated result through the lvalue.
1014 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1016 // If this is a postinc, return the value read from memory, otherwise use the
1018 return isPre ? IncVal : InVal;
1021 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
1022 CodeGenFunction *CGF) {
1023 // Bind VLAs in the cast type.
1024 if (CGF && E->getType()->isVariablyModifiedType())
1025 CGF->EmitVariablyModifiedType(E->getType());
1027 if (CGDebugInfo *DI = getModuleDebugInfo())
1028 DI->EmitExplicitCastType(E->getType());
1031 //===----------------------------------------------------------------------===//
1032 // LValue Expression Emission
1033 //===----------------------------------------------------------------------===//
1035 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1036 /// derive a more accurate bound on the alignment of the pointer.
1037 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
1038 LValueBaseInfo *BaseInfo,
1039 TBAAAccessInfo *TBAAInfo) {
1040 // We allow this with ObjC object pointers because of fragile ABIs.
1041 assert(E->getType()->isPointerType() ||
1042 E->getType()->isObjCObjectPointerType());
1043 E = E->IgnoreParens();
1046 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1047 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1048 CGM.EmitExplicitCastExprType(ECE, this);
1050 switch (CE->getCastKind()) {
1051 // Non-converting casts (but not C's implicit conversion from void*).
1054 case CK_AddressSpaceConversion:
1055 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1056 if (PtrTy->getPointeeType()->isVoidType())
1059 LValueBaseInfo InnerBaseInfo;
1060 TBAAAccessInfo InnerTBAAInfo;
1061 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1064 if (BaseInfo) *BaseInfo = InnerBaseInfo;
1065 if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1067 if (isa<ExplicitCastExpr>(CE)) {
1068 LValueBaseInfo TargetTypeBaseInfo;
1069 TBAAAccessInfo TargetTypeTBAAInfo;
1070 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
1071 &TargetTypeBaseInfo,
1072 &TargetTypeTBAAInfo);
1074 *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1075 TargetTypeTBAAInfo);
1076 // If the source l-value is opaque, honor the alignment of the
1078 if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1080 BaseInfo->mergeForCast(TargetTypeBaseInfo);
1081 Addr = Address(Addr.getPointer(), Align);
1085 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1086 CE->getCastKind() == CK_BitCast) {
1087 if (auto PT = E->getType()->getAs<PointerType>())
1088 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1090 CodeGenFunction::CFITCK_UnrelatedCast,
1093 return CE->getCastKind() != CK_AddressSpaceConversion
1094 ? Builder.CreateBitCast(Addr, ConvertType(E->getType()))
1095 : Builder.CreateAddrSpaceCast(Addr,
1096 ConvertType(E->getType()));
1100 // Array-to-pointer decay.
1101 case CK_ArrayToPointerDecay:
1102 return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1104 // Derived-to-base conversions.
1105 case CK_UncheckedDerivedToBase:
1106 case CK_DerivedToBase: {
1107 // TODO: Support accesses to members of base classes in TBAA. For now, we
1108 // conservatively pretend that the complete object is of the base class
1111 *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1112 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1113 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1114 return GetAddressOfBaseClass(Addr, Derived,
1115 CE->path_begin(), CE->path_end(),
1116 ShouldNullCheckClassCastValue(CE),
1120 // TODO: Is there any reason to treat base-to-derived conversions
1128 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1129 if (UO->getOpcode() == UO_AddrOf) {
1130 LValue LV = EmitLValue(UO->getSubExpr());
1131 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1132 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1133 return LV.getAddress();
1137 // TODO: conditional operators, comma.
1139 // Otherwise, use the alignment of the type.
1140 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo,
1142 return Address(EmitScalarExpr(E), Align);
1145 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
1146 if (Ty->isVoidType())
1147 return RValue::get(nullptr);
1149 switch (getEvaluationKind(Ty)) {
1152 ConvertType(Ty->castAs<ComplexType>()->getElementType());
1153 llvm::Value *U = llvm::UndefValue::get(EltTy);
1154 return RValue::getComplex(std::make_pair(U, U));
1157 // If this is a use of an undefined aggregate type, the aggregate must have an
1158 // identifiable address. Just because the contents of the value are undefined
1159 // doesn't mean that the address can't be taken and compared.
1160 case TEK_Aggregate: {
1161 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1162 return RValue::getAggregate(DestPtr);
1166 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1168 llvm_unreachable("bad evaluation kind");
1171 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
1173 ErrorUnsupported(E, Name);
1174 return GetUndefRValue(E->getType());
1177 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
1179 ErrorUnsupported(E, Name);
1180 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1181 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1185 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
1186 const Expr *Base = Obj;
1187 while (!isa<CXXThisExpr>(Base)) {
1188 // The result of a dynamic_cast can be null.
1189 if (isa<CXXDynamicCastExpr>(Base))
1192 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1193 Base = CE->getSubExpr();
1194 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1195 Base = PE->getSubExpr();
1196 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1197 if (UO->getOpcode() == UO_Extension)
1198 Base = UO->getSubExpr();
1208 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1210 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1211 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1214 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1215 SanitizerSet SkippedChecks;
1216 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1217 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1219 SkippedChecks.set(SanitizerKind::Alignment, true);
1220 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1221 SkippedChecks.set(SanitizerKind::Null, true);
1223 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1224 E->getType(), LV.getAlignment(), SkippedChecks);
1229 /// EmitLValue - Emit code to compute a designator that specifies the location
1230 /// of the expression.
1232 /// This can return one of two things: a simple address or a bitfield reference.
1233 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1234 /// an LLVM pointer type.
1236 /// If this returns a bitfield reference, nothing about the pointee type of the
1237 /// LLVM value is known: For example, it may not be a pointer to an integer.
1239 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1240 /// this method guarantees that the returned pointer type will point to an LLVM
1241 /// type of the same size of the lvalue's type. If the lvalue has a variable
1242 /// length type, this is not possible.
1244 LValue CodeGenFunction::EmitLValue(const Expr *E) {
1245 ApplyDebugLocation DL(*this, E);
1246 switch (E->getStmtClass()) {
1247 default: return EmitUnsupportedLValue(E, "l-value expression");
1249 case Expr::ObjCPropertyRefExprClass:
1250 llvm_unreachable("cannot emit a property reference directly");
1252 case Expr::ObjCSelectorExprClass:
1253 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1254 case Expr::ObjCIsaExprClass:
1255 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1256 case Expr::BinaryOperatorClass:
1257 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1258 case Expr::CompoundAssignOperatorClass: {
1259 QualType Ty = E->getType();
1260 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1261 Ty = AT->getValueType();
1262 if (!Ty->isAnyComplexType())
1263 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1264 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1266 case Expr::CallExprClass:
1267 case Expr::CXXMemberCallExprClass:
1268 case Expr::CXXOperatorCallExprClass:
1269 case Expr::UserDefinedLiteralClass:
1270 return EmitCallExprLValue(cast<CallExpr>(E));
1271 case Expr::VAArgExprClass:
1272 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1273 case Expr::DeclRefExprClass:
1274 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1275 case Expr::ConstantExprClass:
1276 return EmitLValue(cast<ConstantExpr>(E)->getSubExpr());
1277 case Expr::ParenExprClass:
1278 return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1279 case Expr::GenericSelectionExprClass:
1280 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1281 case Expr::PredefinedExprClass:
1282 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1283 case Expr::StringLiteralClass:
1284 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1285 case Expr::ObjCEncodeExprClass:
1286 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1287 case Expr::PseudoObjectExprClass:
1288 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1289 case Expr::InitListExprClass:
1290 return EmitInitListLValue(cast<InitListExpr>(E));
1291 case Expr::CXXTemporaryObjectExprClass:
1292 case Expr::CXXConstructExprClass:
1293 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1294 case Expr::CXXBindTemporaryExprClass:
1295 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1296 case Expr::CXXUuidofExprClass:
1297 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1298 case Expr::LambdaExprClass:
1299 return EmitAggExprToLValue(E);
1301 case Expr::ExprWithCleanupsClass: {
1302 const auto *cleanups = cast<ExprWithCleanups>(E);
1303 enterFullExpression(cleanups);
1304 RunCleanupsScope Scope(*this);
1305 LValue LV = EmitLValue(cleanups->getSubExpr());
1306 if (LV.isSimple()) {
1307 // Defend against branches out of gnu statement expressions surrounded by
1309 llvm::Value *V = LV.getPointer();
1310 Scope.ForceCleanup({&V});
1311 return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1312 getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1314 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1315 // bitfield lvalue or some other non-simple lvalue?
1319 case Expr::CXXDefaultArgExprClass: {
1320 auto *DAE = cast<CXXDefaultArgExpr>(E);
1321 CXXDefaultArgExprScope Scope(*this, DAE);
1322 return EmitLValue(DAE->getExpr());
1324 case Expr::CXXDefaultInitExprClass: {
1325 auto *DIE = cast<CXXDefaultInitExpr>(E);
1326 CXXDefaultInitExprScope Scope(*this, DIE);
1327 return EmitLValue(DIE->getExpr());
1329 case Expr::CXXTypeidExprClass:
1330 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1332 case Expr::ObjCMessageExprClass:
1333 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1334 case Expr::ObjCIvarRefExprClass:
1335 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1336 case Expr::StmtExprClass:
1337 return EmitStmtExprLValue(cast<StmtExpr>(E));
1338 case Expr::UnaryOperatorClass:
1339 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1340 case Expr::ArraySubscriptExprClass:
1341 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1342 case Expr::OMPArraySectionExprClass:
1343 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1344 case Expr::ExtVectorElementExprClass:
1345 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1346 case Expr::MemberExprClass:
1347 return EmitMemberExpr(cast<MemberExpr>(E));
1348 case Expr::CompoundLiteralExprClass:
1349 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1350 case Expr::ConditionalOperatorClass:
1351 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1352 case Expr::BinaryConditionalOperatorClass:
1353 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1354 case Expr::ChooseExprClass:
1355 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1356 case Expr::OpaqueValueExprClass:
1357 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1358 case Expr::SubstNonTypeTemplateParmExprClass:
1359 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1360 case Expr::ImplicitCastExprClass:
1361 case Expr::CStyleCastExprClass:
1362 case Expr::CXXFunctionalCastExprClass:
1363 case Expr::CXXStaticCastExprClass:
1364 case Expr::CXXDynamicCastExprClass:
1365 case Expr::CXXReinterpretCastExprClass:
1366 case Expr::CXXConstCastExprClass:
1367 case Expr::ObjCBridgedCastExprClass:
1368 return EmitCastLValue(cast<CastExpr>(E));
1370 case Expr::MaterializeTemporaryExprClass:
1371 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1373 case Expr::CoawaitExprClass:
1374 return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1375 case Expr::CoyieldExprClass:
1376 return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1380 /// Given an object of the given canonical type, can we safely copy a
1381 /// value out of it based on its initializer?
1382 static bool isConstantEmittableObjectType(QualType type) {
1383 assert(type.isCanonical());
1384 assert(!type->isReferenceType());
1386 // Must be const-qualified but non-volatile.
1387 Qualifiers qs = type.getLocalQualifiers();
1388 if (!qs.hasConst() || qs.hasVolatile()) return false;
1390 // Otherwise, all object types satisfy this except C++ classes with
1391 // mutable subobjects or non-trivial copy/destroy behavior.
1392 if (const auto *RT = dyn_cast<RecordType>(type))
1393 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1394 if (RD->hasMutableFields() || !RD->isTrivial())
1400 /// Can we constant-emit a load of a reference to a variable of the
1401 /// given type? This is different from predicates like
1402 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1403 /// in situations that don't necessarily satisfy the language's rules
1404 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1405 /// to do this with const float variables even if those variables
1406 /// aren't marked 'constexpr'.
1407 enum ConstantEmissionKind {
1409 CEK_AsReferenceOnly,
1410 CEK_AsValueOrReference,
1413 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1414 type = type.getCanonicalType();
1415 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1416 if (isConstantEmittableObjectType(ref->getPointeeType()))
1417 return CEK_AsValueOrReference;
1418 return CEK_AsReferenceOnly;
1420 if (isConstantEmittableObjectType(type))
1421 return CEK_AsValueOnly;
1425 /// Try to emit a reference to the given value without producing it as
1426 /// an l-value. This is just an optimization, but it avoids us needing
1427 /// to emit global copies of variables if they're named without triggering
1428 /// a formal use in a context where we can't emit a direct reference to them,
1429 /// for instance if a block or lambda or a member of a local class uses a
1430 /// const int variable or constexpr variable from an enclosing function.
1431 CodeGenFunction::ConstantEmission
1432 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1433 ValueDecl *value = refExpr->getDecl();
1435 // The value needs to be an enum constant or a constant variable.
1436 ConstantEmissionKind CEK;
1437 if (isa<ParmVarDecl>(value)) {
1439 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1440 CEK = checkVarTypeForConstantEmission(var->getType());
1441 } else if (isa<EnumConstantDecl>(value)) {
1442 CEK = CEK_AsValueOnly;
1446 if (CEK == CEK_None) return ConstantEmission();
1448 Expr::EvalResult result;
1449 bool resultIsReference;
1450 QualType resultType;
1452 // It's best to evaluate all the way as an r-value if that's permitted.
1453 if (CEK != CEK_AsReferenceOnly &&
1454 refExpr->EvaluateAsRValue(result, getContext())) {
1455 resultIsReference = false;
1456 resultType = refExpr->getType();
1458 // Otherwise, try to evaluate as an l-value.
1459 } else if (CEK != CEK_AsValueOnly &&
1460 refExpr->EvaluateAsLValue(result, getContext())) {
1461 resultIsReference = true;
1462 resultType = value->getType();
1466 return ConstantEmission();
1469 // In any case, if the initializer has side-effects, abandon ship.
1470 if (result.HasSideEffects)
1471 return ConstantEmission();
1473 // Emit as a constant.
1474 auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1475 result.Val, resultType);
1477 // Make sure we emit a debug reference to the global variable.
1478 // This should probably fire even for
1479 if (isa<VarDecl>(value)) {
1480 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1481 EmitDeclRefExprDbgValue(refExpr, result.Val);
1483 assert(isa<EnumConstantDecl>(value));
1484 EmitDeclRefExprDbgValue(refExpr, result.Val);
1487 // If we emitted a reference constant, we need to dereference that.
1488 if (resultIsReference)
1489 return ConstantEmission::forReference(C);
1491 return ConstantEmission::forValue(C);
1494 static DeclRefExpr *tryToConvertMemberExprToDeclRefExpr(CodeGenFunction &CGF,
1495 const MemberExpr *ME) {
1496 if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1497 // Try to emit static variable member expressions as DREs.
1498 return DeclRefExpr::Create(
1499 CGF.getContext(), NestedNameSpecifierLoc(), SourceLocation(), VD,
1500 /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1501 ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1506 CodeGenFunction::ConstantEmission
1507 CodeGenFunction::tryEmitAsConstant(const MemberExpr *ME) {
1508 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1509 return tryEmitAsConstant(DRE);
1510 return ConstantEmission();
1513 llvm::Value *CodeGenFunction::emitScalarConstant(
1514 const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1515 assert(Constant && "not a constant");
1516 if (Constant.isReference())
1517 return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1520 return Constant.getValue();
1523 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1524 SourceLocation Loc) {
1525 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1526 lvalue.getType(), Loc, lvalue.getBaseInfo(),
1527 lvalue.getTBAAInfo(), lvalue.isNontemporal());
1530 static bool hasBooleanRepresentation(QualType Ty) {
1531 if (Ty->isBooleanType())
1534 if (const EnumType *ET = Ty->getAs<EnumType>())
1535 return ET->getDecl()->getIntegerType()->isBooleanType();
1537 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1538 return hasBooleanRepresentation(AT->getValueType());
1543 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1544 llvm::APInt &Min, llvm::APInt &End,
1545 bool StrictEnums, bool IsBool) {
1546 const EnumType *ET = Ty->getAs<EnumType>();
1547 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1548 ET && !ET->getDecl()->isFixed();
1549 if (!IsBool && !IsRegularCPlusPlusEnum)
1553 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1554 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1556 const EnumDecl *ED = ET->getDecl();
1557 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1558 unsigned Bitwidth = LTy->getScalarSizeInBits();
1559 unsigned NumNegativeBits = ED->getNumNegativeBits();
1560 unsigned NumPositiveBits = ED->getNumPositiveBits();
1562 if (NumNegativeBits) {
1563 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1564 assert(NumBits <= Bitwidth);
1565 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1568 assert(NumPositiveBits <= Bitwidth);
1569 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1570 Min = llvm::APInt(Bitwidth, 0);
1576 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1577 llvm::APInt Min, End;
1578 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1579 hasBooleanRepresentation(Ty)))
1582 llvm::MDBuilder MDHelper(getLLVMContext());
1583 return MDHelper.createRange(Min, End);
1586 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1587 SourceLocation Loc) {
1588 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1589 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1590 if (!HasBoolCheck && !HasEnumCheck)
1593 bool IsBool = hasBooleanRepresentation(Ty) ||
1594 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1595 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1596 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1597 if (!NeedsBoolCheck && !NeedsEnumCheck)
1600 // Single-bit booleans don't need to be checked. Special-case this to avoid
1601 // a bit width mismatch when handling bitfield values. This is handled by
1602 // EmitFromMemory for the non-bitfield case.
1604 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1607 llvm::APInt Min, End;
1608 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1611 auto &Ctx = getLLVMContext();
1612 SanitizerScope SanScope(this);
1616 Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1618 llvm::Value *Upper =
1619 Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1620 llvm::Value *Lower =
1621 Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1622 Check = Builder.CreateAnd(Upper, Lower);
1624 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1625 EmitCheckTypeDescriptor(Ty)};
1626 SanitizerMask Kind =
1627 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1628 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1629 StaticArgs, EmitCheckValue(Value));
1633 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1636 LValueBaseInfo BaseInfo,
1637 TBAAAccessInfo TBAAInfo,
1638 bool isNontemporal) {
1639 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1640 // For better performance, handle vector loads differently.
1641 if (Ty->isVectorType()) {
1642 const llvm::Type *EltTy = Addr.getElementType();
1644 const auto *VTy = cast<llvm::VectorType>(EltTy);
1646 // Handle vectors of size 3 like size 4 for better performance.
1647 if (VTy->getNumElements() == 3) {
1649 // Bitcast to vec4 type.
1650 llvm::VectorType *vec4Ty =
1651 llvm::VectorType::get(VTy->getElementType(), 4);
1652 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1654 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1656 // Shuffle vector to get vec3.
1657 V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1658 {0, 1, 2}, "extractVec");
1659 return EmitFromMemory(V, Ty);
1664 // Atomic operations have to be done on integral types.
1665 LValue AtomicLValue =
1666 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1667 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1668 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1671 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1672 if (isNontemporal) {
1673 llvm::MDNode *Node = llvm::MDNode::get(
1674 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1675 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1678 CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1680 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1681 // In order to prevent the optimizer from throwing away the check, don't
1682 // attach range metadata to the load.
1683 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1684 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1685 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1687 return EmitFromMemory(Load, Ty);
1690 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1691 // Bool has a different representation in memory than in registers.
1692 if (hasBooleanRepresentation(Ty)) {
1693 // This should really always be an i1, but sometimes it's already
1694 // an i8, and it's awkward to track those cases down.
1695 if (Value->getType()->isIntegerTy(1))
1696 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1697 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1698 "wrong value rep of bool");
1704 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1705 // Bool has a different representation in memory than in registers.
1706 if (hasBooleanRepresentation(Ty)) {
1707 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1708 "wrong value rep of bool");
1709 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1715 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1716 bool Volatile, QualType Ty,
1717 LValueBaseInfo BaseInfo,
1718 TBAAAccessInfo TBAAInfo,
1719 bool isInit, bool isNontemporal) {
1720 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1721 // Handle vectors differently to get better performance.
1722 if (Ty->isVectorType()) {
1723 llvm::Type *SrcTy = Value->getType();
1724 auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1725 // Handle vec3 special.
1726 if (VecTy && VecTy->getNumElements() == 3) {
1727 // Our source is a vec3, do a shuffle vector to make it a vec4.
1728 llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1729 Builder.getInt32(2),
1730 llvm::UndefValue::get(Builder.getInt32Ty())};
1731 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1732 Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1733 MaskV, "extractVec");
1734 SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1736 if (Addr.getElementType() != SrcTy) {
1737 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1742 Value = EmitToMemory(Value, Ty);
1744 LValue AtomicLValue =
1745 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1746 if (Ty->isAtomicType() ||
1747 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1748 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1752 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1753 if (isNontemporal) {
1754 llvm::MDNode *Node =
1755 llvm::MDNode::get(Store->getContext(),
1756 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1757 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1760 CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1763 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1765 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1766 lvalue.getType(), lvalue.getBaseInfo(),
1767 lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1770 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1771 /// method emits the address of the lvalue, then loads the result as an rvalue,
1772 /// returning the rvalue.
1773 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1774 if (LV.isObjCWeak()) {
1775 // load of a __weak object.
1776 Address AddrWeakObj = LV.getAddress();
1777 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1780 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1781 // In MRC mode, we do a load+autorelease.
1782 if (!getLangOpts().ObjCAutoRefCount) {
1783 return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1786 // In ARC mode, we load retained and then consume the value.
1787 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
1788 Object = EmitObjCConsumeObject(LV.getType(), Object);
1789 return RValue::get(Object);
1792 if (LV.isSimple()) {
1793 assert(!LV.getType()->isFunctionType());
1795 // Everything needs a load.
1796 return RValue::get(EmitLoadOfScalar(LV, Loc));
1799 if (LV.isVectorElt()) {
1800 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1801 LV.isVolatileQualified());
1802 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1806 // If this is a reference to a subset of the elements of a vector, either
1807 // shuffle the input or extract/insert them as appropriate.
1808 if (LV.isExtVectorElt())
1809 return EmitLoadOfExtVectorElementLValue(LV);
1811 // Global Register variables always invoke intrinsics
1812 if (LV.isGlobalReg())
1813 return EmitLoadOfGlobalRegLValue(LV);
1815 assert(LV.isBitField() && "Unknown LValue type!");
1816 return EmitLoadOfBitfieldLValue(LV, Loc);
1819 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
1820 SourceLocation Loc) {
1821 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1823 // Get the output type.
1824 llvm::Type *ResLTy = ConvertType(LV.getType());
1826 Address Ptr = LV.getBitFieldAddress();
1827 llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1829 if (Info.IsSigned) {
1830 assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1831 unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1833 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1834 if (Info.Offset + HighBits)
1835 Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1838 Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1839 if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1840 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1844 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1845 EmitScalarRangeCheck(Val, LV.getType(), Loc);
1846 return RValue::get(Val);
1849 // If this is a reference to a subset of the elements of a vector, create an
1850 // appropriate shufflevector.
1851 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1852 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1853 LV.isVolatileQualified());
1855 const llvm::Constant *Elts = LV.getExtVectorElts();
1857 // If the result of the expression is a non-vector type, we must be extracting
1858 // a single element. Just codegen as an extractelement.
1859 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1861 unsigned InIdx = getAccessedFieldNo(0, Elts);
1862 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1863 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1866 // Always use shuffle vector to try to retain the original program structure
1867 unsigned NumResultElts = ExprVT->getNumElements();
1869 SmallVector<llvm::Constant*, 4> Mask;
1870 for (unsigned i = 0; i != NumResultElts; ++i)
1871 Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1873 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1874 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1876 return RValue::get(Vec);
1879 /// Generates lvalue for partial ext_vector access.
1880 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
1881 Address VectorAddress = LV.getExtVectorAddress();
1882 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1883 QualType EQT = ExprVT->getElementType();
1884 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1886 Address CastToPointerElement =
1887 Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1888 "conv.ptr.element");
1890 const llvm::Constant *Elts = LV.getExtVectorElts();
1891 unsigned ix = getAccessedFieldNo(0, Elts);
1893 Address VectorBasePtrPlusIx =
1894 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1897 return VectorBasePtrPlusIx;
1900 /// Load of global gamed gegisters are always calls to intrinsics.
1901 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
1902 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1903 "Bad type for register variable");
1904 llvm::MDNode *RegName = cast<llvm::MDNode>(
1905 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1907 // We accept integer and pointer types only
1908 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1909 llvm::Type *Ty = OrigTy;
1910 if (OrigTy->isPointerTy())
1911 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1912 llvm::Type *Types[] = { Ty };
1914 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1915 llvm::Value *Call = Builder.CreateCall(
1916 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1917 if (OrigTy->isPointerTy())
1918 Call = Builder.CreateIntToPtr(Call, OrigTy);
1919 return RValue::get(Call);
1923 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1924 /// lvalue, where both are guaranteed to the have the same type, and that type
1926 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
1928 if (!Dst.isSimple()) {
1929 if (Dst.isVectorElt()) {
1930 // Read/modify/write the vector, inserting the new element.
1931 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
1932 Dst.isVolatileQualified());
1933 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1934 Dst.getVectorIdx(), "vecins");
1935 Builder.CreateStore(Vec, Dst.getVectorAddress(),
1936 Dst.isVolatileQualified());
1940 // If this is an update of extended vector elements, insert them as
1942 if (Dst.isExtVectorElt())
1943 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
1945 if (Dst.isGlobalReg())
1946 return EmitStoreThroughGlobalRegLValue(Src, Dst);
1948 assert(Dst.isBitField() && "Unknown LValue type");
1949 return EmitStoreThroughBitfieldLValue(Src, Dst);
1952 // There's special magic for assigning into an ARC-qualified l-value.
1953 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1955 case Qualifiers::OCL_None:
1956 llvm_unreachable("present but none");
1958 case Qualifiers::OCL_ExplicitNone:
1962 case Qualifiers::OCL_Strong:
1964 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1967 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1970 case Qualifiers::OCL_Weak:
1972 // Initialize and then skip the primitive store.
1973 EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1975 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1978 case Qualifiers::OCL_Autoreleasing:
1979 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
1980 Src.getScalarVal()));
1981 // fall into the normal path
1986 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1987 // load of a __weak object.
1988 Address LvalueDst = Dst.getAddress();
1989 llvm::Value *src = Src.getScalarVal();
1990 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1994 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1995 // load of a __strong object.
1996 Address LvalueDst = Dst.getAddress();
1997 llvm::Value *src = Src.getScalarVal();
1998 if (Dst.isObjCIvar()) {
1999 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2000 llvm::Type *ResultType = IntPtrTy;
2001 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
2002 llvm::Value *RHS = dst.getPointer();
2003 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2005 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
2006 "sub.ptr.lhs.cast");
2007 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2008 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2010 } else if (Dst.isGlobalObjCRef()) {
2011 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2012 Dst.isThreadLocalRef());
2015 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2019 assert(Src.isScalar() && "Can't emit an agg store with this method");
2020 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2023 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
2024 llvm::Value **Result) {
2025 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2026 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2027 Address Ptr = Dst.getBitFieldAddress();
2029 // Get the source value, truncated to the width of the bit-field.
2030 llvm::Value *SrcVal = Src.getScalarVal();
2032 // Cast the source to the storage type and shift it into place.
2033 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2034 /*isSigned=*/false);
2035 llvm::Value *MaskedVal = SrcVal;
2037 // See if there are other bits in the bitfield's storage we'll need to load
2038 // and mask together with source before storing.
2039 if (Info.StorageSize != Info.Size) {
2040 assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
2042 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2044 // Mask the source value as needed.
2045 if (!hasBooleanRepresentation(Dst.getType()))
2046 SrcVal = Builder.CreateAnd(SrcVal,
2047 llvm::APInt::getLowBitsSet(Info.StorageSize,
2052 SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
2054 // Mask out the original value.
2055 Val = Builder.CreateAnd(Val,
2056 ~llvm::APInt::getBitsSet(Info.StorageSize,
2058 Info.Offset + Info.Size),
2061 // Or together the unchanged values and the source value.
2062 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2064 assert(Info.Offset == 0);
2067 // Write the new value back out.
2068 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2070 // Return the new value of the bit-field, if requested.
2072 llvm::Value *ResultVal = MaskedVal;
2074 // Sign extend the value if needed.
2075 if (Info.IsSigned) {
2076 assert(Info.Size <= Info.StorageSize);
2077 unsigned HighBits = Info.StorageSize - Info.Size;
2079 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2080 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2084 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2086 *Result = EmitFromMemory(ResultVal, Dst.getType());
2090 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
2092 // This access turns into a read/modify/write of the vector. Load the input
2094 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
2095 Dst.isVolatileQualified());
2096 const llvm::Constant *Elts = Dst.getExtVectorElts();
2098 llvm::Value *SrcVal = Src.getScalarVal();
2100 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2101 unsigned NumSrcElts = VTy->getNumElements();
2102 unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2103 if (NumDstElts == NumSrcElts) {
2104 // Use shuffle vector is the src and destination are the same number of
2105 // elements and restore the vector mask since it is on the side it will be
2107 SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2108 for (unsigned i = 0; i != NumSrcElts; ++i)
2109 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2111 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2112 Vec = Builder.CreateShuffleVector(SrcVal,
2113 llvm::UndefValue::get(Vec->getType()),
2115 } else if (NumDstElts > NumSrcElts) {
2116 // Extended the source vector to the same length and then shuffle it
2117 // into the destination.
2118 // FIXME: since we're shuffling with undef, can we just use the indices
2119 // into that? This could be simpler.
2120 SmallVector<llvm::Constant*, 4> ExtMask;
2121 for (unsigned i = 0; i != NumSrcElts; ++i)
2122 ExtMask.push_back(Builder.getInt32(i));
2123 ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2124 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2125 llvm::Value *ExtSrcVal =
2126 Builder.CreateShuffleVector(SrcVal,
2127 llvm::UndefValue::get(SrcVal->getType()),
2130 SmallVector<llvm::Constant*, 4> Mask;
2131 for (unsigned i = 0; i != NumDstElts; ++i)
2132 Mask.push_back(Builder.getInt32(i));
2134 // When the vector size is odd and .odd or .hi is used, the last element
2135 // of the Elts constant array will be one past the size of the vector.
2136 // Ignore the last element here, if it is greater than the mask size.
2137 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2140 // modify when what gets shuffled in
2141 for (unsigned i = 0; i != NumSrcElts; ++i)
2142 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2143 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2144 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2146 // We should never shorten the vector
2147 llvm_unreachable("unexpected shorten vector length");
2150 // If the Src is a scalar (not a vector) it must be updating one element.
2151 unsigned InIdx = getAccessedFieldNo(0, Elts);
2152 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2153 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2156 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
2157 Dst.isVolatileQualified());
2160 /// Store of global named registers are always calls to intrinsics.
2161 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
2162 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2163 "Bad type for register variable");
2164 llvm::MDNode *RegName = cast<llvm::MDNode>(
2165 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2166 assert(RegName && "Register LValue is not metadata");
2168 // We accept integer and pointer types only
2169 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2170 llvm::Type *Ty = OrigTy;
2171 if (OrigTy->isPointerTy())
2172 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2173 llvm::Type *Types[] = { Ty };
2175 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2176 llvm::Value *Value = Src.getScalarVal();
2177 if (OrigTy->isPointerTy())
2178 Value = Builder.CreatePtrToInt(Value, Ty);
2180 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2183 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2184 // generating write-barries API. It is currently a global, ivar,
2186 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2188 bool IsMemberAccess=false) {
2189 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2192 if (isa<ObjCIvarRefExpr>(E)) {
2193 QualType ExpTy = E->getType();
2194 if (IsMemberAccess && ExpTy->isPointerType()) {
2195 // If ivar is a structure pointer, assigning to field of
2196 // this struct follows gcc's behavior and makes it a non-ivar
2197 // writer-barrier conservatively.
2198 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2199 if (ExpTy->isRecordType()) {
2200 LV.setObjCIvar(false);
2204 LV.setObjCIvar(true);
2205 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2206 LV.setBaseIvarExp(Exp->getBase());
2207 LV.setObjCArray(E->getType()->isArrayType());
2211 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2212 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2213 if (VD->hasGlobalStorage()) {
2214 LV.setGlobalObjCRef(true);
2215 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2218 LV.setObjCArray(E->getType()->isArrayType());
2222 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2223 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2227 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2228 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2229 if (LV.isObjCIvar()) {
2230 // If cast is to a structure pointer, follow gcc's behavior and make it
2231 // a non-ivar write-barrier.
2232 QualType ExpTy = E->getType();
2233 if (ExpTy->isPointerType())
2234 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2235 if (ExpTy->isRecordType())
2236 LV.setObjCIvar(false);
2241 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2242 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2246 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2247 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2251 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2252 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2256 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2257 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2261 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2262 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2263 if (LV.isObjCIvar() && !LV.isObjCArray())
2264 // Using array syntax to assigning to what an ivar points to is not
2265 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2266 LV.setObjCIvar(false);
2267 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2268 // Using array syntax to assigning to what global points to is not
2269 // same as assigning to the global itself. {id *G;} G[i] = 0;
2270 LV.setGlobalObjCRef(false);
2274 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2275 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2276 // We don't know if member is an 'ivar', but this flag is looked at
2277 // only in the context of LV.isObjCIvar().
2278 LV.setObjCArray(E->getType()->isArrayType());
2283 static llvm::Value *
2284 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
2285 llvm::Value *V, llvm::Type *IRType,
2286 StringRef Name = StringRef()) {
2287 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2288 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2291 static LValue EmitThreadPrivateVarDeclLValue(
2292 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2293 llvm::Type *RealVarTy, SourceLocation Loc) {
2294 Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2295 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2296 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2299 static Address emitDeclTargetVarDeclLValue(CodeGenFunction &CGF,
2300 const VarDecl *VD, QualType T) {
2301 llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2302 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2303 // Return an invalid address if variable is MT_To and unified
2304 // memory is not enabled. For all other cases: MT_Link and
2305 // MT_To with unified memory, return a valid address.
2306 if (!Res || (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2307 !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory()))
2308 return Address::invalid();
2309 assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2310 (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2311 CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) &&
2312 "Expected link clause OR to clause with unified memory enabled.");
2313 QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2314 Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2315 return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2319 CodeGenFunction::EmitLoadOfReference(LValue RefLVal,
2320 LValueBaseInfo *PointeeBaseInfo,
2321 TBAAAccessInfo *PointeeTBAAInfo) {
2322 llvm::LoadInst *Load = Builder.CreateLoad(RefLVal.getAddress(),
2323 RefLVal.isVolatile());
2324 CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2326 CharUnits Align = getNaturalTypeAlignment(RefLVal.getType()->getPointeeType(),
2327 PointeeBaseInfo, PointeeTBAAInfo,
2328 /* forPointeeType= */ true);
2329 return Address(Load, Align);
2332 LValue CodeGenFunction::EmitLoadOfReferenceLValue(LValue RefLVal) {
2333 LValueBaseInfo PointeeBaseInfo;
2334 TBAAAccessInfo PointeeTBAAInfo;
2335 Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2337 return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2338 PointeeBaseInfo, PointeeTBAAInfo);
2341 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2342 const PointerType *PtrTy,
2343 LValueBaseInfo *BaseInfo,
2344 TBAAAccessInfo *TBAAInfo) {
2345 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2346 return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2348 /*forPointeeType=*/true));
2351 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2352 const PointerType *PtrTy) {
2353 LValueBaseInfo BaseInfo;
2354 TBAAAccessInfo TBAAInfo;
2355 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2356 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2359 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2360 const Expr *E, const VarDecl *VD) {
2361 QualType T = E->getType();
2363 // If it's thread_local, emit a call to its wrapper function instead.
2364 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2365 CGF.CGM.getCXXABI().usesThreadWrapperFunction())
2366 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2367 // Check if the variable is marked as declare target with link clause in
2369 if (CGF.getLangOpts().OpenMPIsDevice) {
2370 Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2372 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2375 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2376 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2377 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2378 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2379 Address Addr(V, Alignment);
2380 // Emit reference to the private copy of the variable if it is an OpenMP
2381 // threadprivate variable.
2382 if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2383 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2384 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2387 LValue LV = VD->getType()->isReferenceType() ?
2388 CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2389 AlignmentSource::Decl) :
2390 CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2391 setObjCGCLValueClass(CGF.getContext(), E, LV);
2395 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2396 const FunctionDecl *FD) {
2397 if (FD->hasAttr<WeakRefAttr>()) {
2398 ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2399 return aliasee.getPointer();
2402 llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2403 if (!FD->hasPrototype()) {
2404 if (const FunctionProtoType *Proto =
2405 FD->getType()->getAs<FunctionProtoType>()) {
2406 // Ugly case: for a K&R-style definition, the type of the definition
2407 // isn't the same as the type of a use. Correct for this with a
2409 QualType NoProtoType =
2410 CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2411 NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2412 V = llvm::ConstantExpr::getBitCast(V,
2413 CGM.getTypes().ConvertType(NoProtoType));
2419 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
2420 const Expr *E, const FunctionDecl *FD) {
2421 llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2422 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2423 return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2424 AlignmentSource::Decl);
2427 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2428 llvm::Value *ThisValue) {
2429 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2430 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2431 return CGF.EmitLValueForField(LV, FD);
2434 /// Named Registers are named metadata pointing to the register name
2435 /// which will be read from/written to as an argument to the intrinsic
2436 /// @llvm.read/write_register.
2437 /// So far, only the name is being passed down, but other options such as
2438 /// register type, allocation type or even optimization options could be
2439 /// passed down via the metadata node.
2440 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2441 SmallString<64> Name("llvm.named.register.");
2442 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2443 assert(Asm->getLabel().size() < 64-Name.size() &&
2444 "Register name too big");
2445 Name.append(Asm->getLabel());
2446 llvm::NamedMDNode *M =
2447 CGM.getModule().getOrInsertNamedMetadata(Name);
2448 if (M->getNumOperands() == 0) {
2449 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2451 llvm::Metadata *Ops[] = {Str};
2452 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2455 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2458 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2459 return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2462 /// Determine whether we can emit a reference to \p VD from the current
2463 /// context, despite not necessarily having seen an odr-use of the variable in
2465 static bool canEmitSpuriousReferenceToVariable(CodeGenFunction &CGF,
2466 const DeclRefExpr *E,
2469 // For a variable declared in an enclosing scope, do not emit a spurious
2470 // reference even if we have a capture, as that will emit an unwarranted
2471 // reference to our capture state, and will likely generate worse code than
2472 // emitting a local copy.
2473 if (E->refersToEnclosingVariableOrCapture())
2476 // For a local declaration declared in this function, we can always reference
2477 // it even if we don't have an odr-use.
2478 if (VD->hasLocalStorage()) {
2479 return VD->getDeclContext() ==
2480 dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2483 // For a global declaration, we can emit a reference to it if we know
2484 // for sure that we are able to emit a definition of it.
2485 VD = VD->getDefinition(CGF.getContext());
2489 // Don't emit a spurious reference if it might be to a variable that only
2490 // exists on a different device / target.
2491 // FIXME: This is unnecessarily broad. Check whether this would actually be a
2492 // cross-target reference.
2493 if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2494 CGF.getLangOpts().OpenCL) {
2498 // We can emit a spurious reference only if the linkage implies that we'll
2499 // be emitting a non-interposable symbol that will be retained until link
2501 switch (CGF.CGM.getLLVMLinkageVarDefinition(VD, IsConstant)) {
2502 case llvm::GlobalValue::ExternalLinkage:
2503 case llvm::GlobalValue::LinkOnceODRLinkage:
2504 case llvm::GlobalValue::WeakODRLinkage:
2505 case llvm::GlobalValue::InternalLinkage:
2506 case llvm::GlobalValue::PrivateLinkage:
2513 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2514 const NamedDecl *ND = E->getDecl();
2515 QualType T = E->getType();
2517 assert(E->isNonOdrUse() != NOUR_Unevaluated &&
2518 "should not emit an unevaluated operand");
2520 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2521 // Global Named registers access via intrinsics only
2522 if (VD->getStorageClass() == SC_Register &&
2523 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2524 return EmitGlobalNamedRegister(VD, CGM);
2526 // If this DeclRefExpr does not constitute an odr-use of the variable,
2527 // we're not permitted to emit a reference to it in general, and it might
2528 // not be captured if capture would be necessary for a use. Emit the
2529 // constant value directly instead.
2530 if (E->isNonOdrUse() == NOUR_Constant &&
2531 (VD->getType()->isReferenceType() ||
2532 !canEmitSpuriousReferenceToVariable(*this, E, VD, true))) {
2533 VD->getAnyInitializer(VD);
2534 llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
2535 E->getLocation(), *VD->evaluateValue(), VD->getType());
2536 assert(Val && "failed to emit constant expression");
2538 Address Addr = Address::invalid();
2539 if (!VD->getType()->isReferenceType()) {
2540 // Spill the constant value to a global.
2541 Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
2542 getContext().getDeclAlign(VD));
2543 llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
2544 auto *PTy = llvm::PointerType::get(
2545 VarTy, getContext().getTargetAddressSpace(VD->getType()));
2546 if (PTy != Addr.getType())
2547 Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy);
2549 // Should we be using the alignment of the constant pointer we emitted?
2550 CharUnits Alignment =
2551 getNaturalTypeAlignment(E->getType(),
2552 /* BaseInfo= */ nullptr,
2553 /* TBAAInfo= */ nullptr,
2554 /* forPointeeType= */ true);
2555 Addr = Address(Val, Alignment);
2557 return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2560 // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
2562 // Check for captured variables.
2563 if (E->refersToEnclosingVariableOrCapture()) {
2564 VD = VD->getCanonicalDecl();
2565 if (auto *FD = LambdaCaptureFields.lookup(VD))
2566 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2567 else if (CapturedStmtInfo) {
2568 auto I = LocalDeclMap.find(VD);
2569 if (I != LocalDeclMap.end()) {
2570 if (VD->getType()->isReferenceType())
2571 return EmitLoadOfReferenceLValue(I->second, VD->getType(),
2572 AlignmentSource::Decl);
2573 return MakeAddrLValue(I->second, T);
2576 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2577 CapturedStmtInfo->getContextValue());
2578 return MakeAddrLValue(
2579 Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2580 CapLVal.getType(), LValueBaseInfo(AlignmentSource::Decl),
2581 CapLVal.getTBAAInfo());
2584 assert(isa<BlockDecl>(CurCodeDecl));
2585 Address addr = GetAddrOfBlockDecl(VD);
2586 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2590 // FIXME: We should be able to assert this for FunctionDecls as well!
2591 // FIXME: We should be able to assert this for all DeclRefExprs, not just
2592 // those with a valid source location.
2593 assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
2594 !E->getLocation().isValid()) &&
2595 "Should not use decl without marking it used!");
2597 if (ND->hasAttr<WeakRefAttr>()) {
2598 const auto *VD = cast<ValueDecl>(ND);
2599 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2600 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2603 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2604 // Check if this is a global variable.
2605 if (VD->hasLinkage() || VD->isStaticDataMember())
2606 return EmitGlobalVarDeclLValue(*this, E, VD);
2608 Address addr = Address::invalid();
2610 // The variable should generally be present in the local decl map.
2611 auto iter = LocalDeclMap.find(VD);
2612 if (iter != LocalDeclMap.end()) {
2613 addr = iter->second;
2615 // Otherwise, it might be static local we haven't emitted yet for
2616 // some reason; most likely, because it's in an outer function.
2617 } else if (VD->isStaticLocal()) {
2618 addr = Address(CGM.getOrCreateStaticVarDecl(
2619 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false)),
2620 getContext().getDeclAlign(VD));
2622 // No other cases for now.
2624 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2628 // Check for OpenMP threadprivate variables.
2629 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2630 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2631 return EmitThreadPrivateVarDeclLValue(
2632 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2636 // Drill into block byref variables.
2637 bool isBlockByref = VD->isEscapingByref();
2639 addr = emitBlockByrefAddress(addr, VD);
2642 // Drill into reference types.
2643 LValue LV = VD->getType()->isReferenceType() ?
2644 EmitLoadOfReferenceLValue(addr, VD->getType(), AlignmentSource::Decl) :
2645 MakeAddrLValue(addr, T, AlignmentSource::Decl);
2647 bool isLocalStorage = VD->hasLocalStorage();
2649 bool NonGCable = isLocalStorage &&
2650 !VD->getType()->isReferenceType() &&
2653 LV.getQuals().removeObjCGCAttr();
2657 bool isImpreciseLifetime =
2658 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2659 if (isImpreciseLifetime)
2660 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2661 setObjCGCLValueClass(getContext(), E, LV);
2665 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2666 return EmitFunctionDeclLValue(*this, E, FD);
2668 // FIXME: While we're emitting a binding from an enclosing scope, all other
2669 // DeclRefExprs we see should be implicitly treated as if they also refer to
2670 // an enclosing scope.
2671 if (const auto *BD = dyn_cast<BindingDecl>(ND))
2672 return EmitLValue(BD->getBinding());
2674 llvm_unreachable("Unhandled DeclRefExpr");
2677 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2678 // __extension__ doesn't affect lvalue-ness.
2679 if (E->getOpcode() == UO_Extension)
2680 return EmitLValue(E->getSubExpr());
2682 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2683 switch (E->getOpcode()) {
2684 default: llvm_unreachable("Unknown unary operator lvalue!");
2686 QualType T = E->getSubExpr()->getType()->getPointeeType();
2687 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2689 LValueBaseInfo BaseInfo;
2690 TBAAAccessInfo TBAAInfo;
2691 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2693 LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2694 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2696 // We should not generate __weak write barrier on indirect reference
2697 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2698 // But, we continue to generate __strong write barrier on indirect write
2699 // into a pointer to object.
2700 if (getLangOpts().ObjC &&
2701 getLangOpts().getGC() != LangOptions::NonGC &&
2703 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2708 LValue LV = EmitLValue(E->getSubExpr());
2709 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2711 // __real is valid on scalars. This is a faster way of testing that.
2712 // __imag can only produce an rvalue on scalars.
2713 if (E->getOpcode() == UO_Real &&
2714 !LV.getAddress().getElementType()->isStructTy()) {
2715 assert(E->getSubExpr()->getType()->isArithmeticType());
2719 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2722 (E->getOpcode() == UO_Real
2723 ? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
2724 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
2725 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2726 CGM.getTBAAInfoForSubobject(LV, T));
2727 ElemLV.getQuals().addQualifiers(LV.getQuals());
2732 LValue LV = EmitLValue(E->getSubExpr());
2733 bool isInc = E->getOpcode() == UO_PreInc;
2735 if (E->getType()->isAnyComplexType())
2736 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2738 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2744 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2745 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2746 E->getType(), AlignmentSource::Decl);
2749 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2750 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2751 E->getType(), AlignmentSource::Decl);
2754 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2755 auto SL = E->getFunctionName();
2756 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2757 StringRef FnName = CurFn->getName();
2758 if (FnName.startswith("\01"))
2759 FnName = FnName.substr(1);
2760 StringRef NameItems[] = {
2761 PredefinedExpr::getIdentKindName(E->getIdentKind()), FnName};
2762 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2763 if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2764 std::string Name = SL->getString();
2765 if (!Name.empty()) {
2766 unsigned Discriminator =
2767 CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2769 Name += "_" + Twine(Discriminator + 1).str();
2770 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2771 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2773 auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2774 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2777 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2778 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2781 /// Emit a type description suitable for use by a runtime sanitizer library. The
2782 /// format of a type descriptor is
2785 /// { i16 TypeKind, i16 TypeInfo }
2788 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2789 /// integer, 1 for a floating point value, and -1 for anything else.
2790 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2791 // Only emit each type's descriptor once.
2792 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2795 uint16_t TypeKind = -1;
2796 uint16_t TypeInfo = 0;
2798 if (T->isIntegerType()) {
2800 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2801 (T->isSignedIntegerType() ? 1 : 0);
2802 } else if (T->isFloatingType()) {
2804 TypeInfo = getContext().getTypeSize(T);
2807 // Format the type name as if for a diagnostic, including quotes and
2808 // optionally an 'aka'.
2809 SmallString<32> Buffer;
2810 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
2811 (intptr_t)T.getAsOpaquePtr(),
2812 StringRef(), StringRef(), None, Buffer,
2815 llvm::Constant *Components[] = {
2816 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2817 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2819 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2821 auto *GV = new llvm::GlobalVariable(
2822 CGM.getModule(), Descriptor->getType(),
2823 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2824 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2825 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
2827 // Remember the descriptor for this type.
2828 CGM.setTypeDescriptorInMap(T, GV);
2833 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
2834 llvm::Type *TargetTy = IntPtrTy;
2836 if (V->getType() == TargetTy)
2839 // Floating-point types which fit into intptr_t are bitcast to integers
2840 // and then passed directly (after zero-extension, if necessary).
2841 if (V->getType()->isFloatingPointTy()) {
2842 unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2843 if (Bits <= TargetTy->getIntegerBitWidth())
2844 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2848 // Integers which fit in intptr_t are zero-extended and passed directly.
2849 if (V->getType()->isIntegerTy() &&
2850 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2851 return Builder.CreateZExt(V, TargetTy);
2853 // Pointers are passed directly, everything else is passed by address.
2854 if (!V->getType()->isPointerTy()) {
2855 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2856 Builder.CreateStore(V, Ptr);
2857 V = Ptr.getPointer();
2859 return Builder.CreatePtrToInt(V, TargetTy);
2862 /// Emit a representation of a SourceLocation for passing to a handler
2863 /// in a sanitizer runtime library. The format for this data is:
2865 /// struct SourceLocation {
2866 /// const char *Filename;
2867 /// int32_t Line, Column;
2870 /// For an invalid SourceLocation, the Filename pointer is null.
2871 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
2872 llvm::Constant *Filename;
2875 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
2876 if (PLoc.isValid()) {
2877 StringRef FilenameString = PLoc.getFilename();
2879 int PathComponentsToStrip =
2880 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2881 if (PathComponentsToStrip < 0) {
2882 assert(PathComponentsToStrip != INT_MIN);
2883 int PathComponentsToKeep = -PathComponentsToStrip;
2884 auto I = llvm::sys::path::rbegin(FilenameString);
2885 auto E = llvm::sys::path::rend(FilenameString);
2886 while (I != E && --PathComponentsToKeep)
2889 FilenameString = FilenameString.substr(I - E);
2890 } else if (PathComponentsToStrip > 0) {
2891 auto I = llvm::sys::path::begin(FilenameString);
2892 auto E = llvm::sys::path::end(FilenameString);
2893 while (I != E && PathComponentsToStrip--)
2898 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2900 FilenameString = llvm::sys::path::filename(FilenameString);
2903 auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2904 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
2905 cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2906 Filename = FilenameGV.getPointer();
2907 Line = PLoc.getLine();
2908 Column = PLoc.getColumn();
2910 Filename = llvm::Constant::getNullValue(Int8PtrTy);
2914 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2915 Builder.getInt32(Column)};
2917 return llvm::ConstantStruct::getAnon(Data);
2921 /// Specify under what conditions this check can be recovered
2922 enum class CheckRecoverableKind {
2923 /// Always terminate program execution if this check fails.
2925 /// Check supports recovering, runtime has both fatal (noreturn) and
2926 /// non-fatal handlers for this check.
2928 /// Runtime conditionally aborts, always need to support recovery.
2933 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
2934 assert(Kind.countPopulation() == 1);
2935 if (Kind == SanitizerKind::Function || Kind == SanitizerKind::Vptr)
2936 return CheckRecoverableKind::AlwaysRecoverable;
2937 else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
2938 return CheckRecoverableKind::Unrecoverable;
2940 return CheckRecoverableKind::Recoverable;
2944 struct SanitizerHandlerInfo {
2945 char const *const Name;
2950 const SanitizerHandlerInfo SanitizerHandlers[] = {
2951 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2952 LIST_SANITIZER_CHECKS
2953 #undef SANITIZER_CHECK
2956 static void emitCheckHandlerCall(CodeGenFunction &CGF,
2957 llvm::FunctionType *FnType,
2958 ArrayRef<llvm::Value *> FnArgs,
2959 SanitizerHandler CheckHandler,
2960 CheckRecoverableKind RecoverKind, bool IsFatal,
2961 llvm::BasicBlock *ContBB) {
2962 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2963 Optional<ApplyDebugLocation> DL;
2964 if (!CGF.Builder.getCurrentDebugLocation()) {
2965 // Ensure that the call has at least an artificial debug location.
2966 DL.emplace(CGF, SourceLocation());
2968 bool NeedsAbortSuffix =
2969 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2970 bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2971 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2972 const StringRef CheckName = CheckInfo.Name;
2973 std::string FnName = "__ubsan_handle_" + CheckName.str();
2974 if (CheckInfo.Version && !MinimalRuntime)
2975 FnName += "_v" + llvm::utostr(CheckInfo.Version);
2977 FnName += "_minimal";
2978 if (NeedsAbortSuffix)
2981 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2983 llvm::AttrBuilder B;
2985 B.addAttribute(llvm::Attribute::NoReturn)
2986 .addAttribute(llvm::Attribute::NoUnwind);
2988 B.addAttribute(llvm::Attribute::UWTable);
2990 llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
2992 llvm::AttributeList::get(CGF.getLLVMContext(),
2993 llvm::AttributeList::FunctionIndex, B),
2995 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2997 HandlerCall->setDoesNotReturn();
2998 CGF.Builder.CreateUnreachable();
3000 CGF.Builder.CreateBr(ContBB);
3004 void CodeGenFunction::EmitCheck(
3005 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3006 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3007 ArrayRef<llvm::Value *> DynamicArgs) {
3008 assert(IsSanitizerScope);
3009 assert(Checked.size() > 0);
3010 assert(CheckHandler >= 0 &&
3011 size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
3012 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3014 llvm::Value *FatalCond = nullptr;
3015 llvm::Value *RecoverableCond = nullptr;
3016 llvm::Value *TrapCond = nullptr;
3017 for (int i = 0, n = Checked.size(); i < n; ++i) {
3018 llvm::Value *Check = Checked[i].first;
3019 // -fsanitize-trap= overrides -fsanitize-recover=.
3020 llvm::Value *&Cond =
3021 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3023 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3026 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3030 EmitTrapCheck(TrapCond);
3031 if (!FatalCond && !RecoverableCond)
3034 llvm::Value *JointCond;
3035 if (FatalCond && RecoverableCond)
3036 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3038 JointCond = FatalCond ? FatalCond : RecoverableCond;
3041 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3042 assert(SanOpts.has(Checked[0].second));
3044 for (int i = 1, n = Checked.size(); i < n; ++i) {
3045 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3046 "All recoverable kinds in a single check must be same!");
3047 assert(SanOpts.has(Checked[i].second));
3051 llvm::BasicBlock *Cont = createBasicBlock("cont");
3052 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3053 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3054 // Give hint that we very much don't expect to execute the handler
3055 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
3056 llvm::MDBuilder MDHelper(getLLVMContext());
3057 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3058 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3059 EmitBlock(Handlers);
3061 // Handler functions take an i8* pointing to the (handler-specific) static
3062 // information block, followed by a sequence of intptr_t arguments
3063 // representing operand values.
3064 SmallVector<llvm::Value *, 4> Args;
3065 SmallVector<llvm::Type *, 4> ArgTypes;
3066 if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3067 Args.reserve(DynamicArgs.size() + 1);
3068 ArgTypes.reserve(DynamicArgs.size() + 1);
3070 // Emit handler arguments and create handler function type.
3071 if (!StaticArgs.empty()) {
3072 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3074 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3075 llvm::GlobalVariable::PrivateLinkage, Info);
3076 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3077 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3078 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
3079 ArgTypes.push_back(Int8PtrTy);
3082 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3083 Args.push_back(EmitCheckValue(DynamicArgs[i]));
3084 ArgTypes.push_back(IntPtrTy);
3088 llvm::FunctionType *FnType =
3089 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3091 if (!FatalCond || !RecoverableCond) {
3092 // Simple case: we need to generate a single handler call, either
3093 // fatal, or non-fatal.
3094 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3095 (FatalCond != nullptr), Cont);
3097 // Emit two handler calls: first one for set of unrecoverable checks,
3098 // another one for recoverable.
3099 llvm::BasicBlock *NonFatalHandlerBB =
3100 createBasicBlock("non_fatal." + CheckName);
3101 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3102 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3103 EmitBlock(FatalHandlerBB);
3104 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3106 EmitBlock(NonFatalHandlerBB);
3107 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3114 void CodeGenFunction::EmitCfiSlowPathCheck(
3115 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3116 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3117 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3119 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3120 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3122 llvm::MDBuilder MDHelper(getLLVMContext());
3123 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3124 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3128 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3130 llvm::CallInst *CheckCall;
3131 llvm::FunctionCallee SlowPathFn;
3133 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3135 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3136 llvm::GlobalVariable::PrivateLinkage, Info);
3137 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3138 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3140 SlowPathFn = CGM.getModule().getOrInsertFunction(
3141 "__cfi_slowpath_diag",
3142 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3144 CheckCall = Builder.CreateCall(
3145 SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3147 SlowPathFn = CGM.getModule().getOrInsertFunction(
3149 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3150 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3154 cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3155 CheckCall->setDoesNotThrow();
3160 // Emit a stub for __cfi_check function so that the linker knows about this
3161 // symbol in LTO mode.
3162 void CodeGenFunction::EmitCfiCheckStub() {
3163 llvm::Module *M = &CGM.getModule();
3164 auto &Ctx = M->getContext();
3165 llvm::Function *F = llvm::Function::Create(
3166 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3167 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3169 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3170 // FIXME: consider emitting an intrinsic call like
3171 // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3172 // which can be lowered in CrossDSOCFI pass to the actual contents of
3173 // __cfi_check. This would allow inlining of __cfi_check calls.
3174 llvm::CallInst::Create(
3175 llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3176 llvm::ReturnInst::Create(Ctx, nullptr, BB);
3179 // This function is basically a switch over the CFI failure kind, which is
3180 // extracted from CFICheckFailData (1st function argument). Each case is either
3181 // llvm.trap or a call to one of the two runtime handlers, based on
3182 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3183 // failure kind) traps, but this should really never happen. CFICheckFailData
3184 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3185 // check kind; in this case __cfi_check_fail traps as well.
3186 void CodeGenFunction::EmitCfiCheckFail() {
3187 SanitizerScope SanScope(this);
3188 FunctionArgList Args;
3189 ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy,
3190 ImplicitParamDecl::Other);
3191 ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy,
3192 ImplicitParamDecl::Other);
3193 Args.push_back(&ArgData);
3194 Args.push_back(&ArgAddr);
3196 const CGFunctionInfo &FI =
3197 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
3199 llvm::Function *F = llvm::Function::Create(
3200 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3201 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3202 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3204 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3207 // This function should not be affected by blacklist. This function does
3208 // not have a source location, but "src:*" would still apply. Revert any
3209 // changes to SanOpts made in StartFunction.
3210 SanOpts = CGM.getLangOpts().Sanitize;
3213 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3214 CGM.getContext().VoidPtrTy, ArgData.getLocation());
3216 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3217 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3219 // Data == nullptr means the calling module has trap behaviour for this check.
3220 llvm::Value *DataIsNotNullPtr =
3221 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3222 EmitTrapCheck(DataIsNotNullPtr);
3224 llvm::StructType *SourceLocationTy =
3225 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3226 llvm::StructType *CfiCheckFailDataTy =
3227 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3229 llvm::Value *V = Builder.CreateConstGEP2_32(
3231 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3233 Address CheckKindAddr(V, getIntAlign());
3234 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3236 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3237 CGM.getLLVMContext(),
3238 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3239 llvm::Value *ValidVtable = Builder.CreateZExt(
3240 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3241 {Addr, AllVtables}),
3244 const std::pair<int, SanitizerMask> CheckKinds[] = {
3245 {CFITCK_VCall, SanitizerKind::CFIVCall},
3246 {CFITCK_NVCall, SanitizerKind::CFINVCall},
3247 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3248 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3249 {CFITCK_ICall, SanitizerKind::CFIICall}};
3251 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
3252 for (auto CheckKindMaskPair : CheckKinds) {
3253 int Kind = CheckKindMaskPair.first;
3254 SanitizerMask Mask = CheckKindMaskPair.second;
3256 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3257 if (CGM.getLangOpts().Sanitize.has(Mask))
3258 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3259 {Data, Addr, ValidVtable});
3261 EmitTrapCheck(Cond);
3265 // The only reference to this function will be created during LTO link.
3266 // Make sure it survives until then.
3267 CGM.addUsedGlobal(F);
3270 void CodeGenFunction::EmitUnreachable(SourceLocation Loc) {
3271 if (SanOpts.has(SanitizerKind::Unreachable)) {
3272 SanitizerScope SanScope(this);
3273 EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3274 SanitizerKind::Unreachable),
3275 SanitizerHandler::BuiltinUnreachable,
3276 EmitCheckSourceLocation(Loc), None);
3278 Builder.CreateUnreachable();
3281 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
3282 llvm::BasicBlock *Cont = createBasicBlock("cont");
3284 // If we're optimizing, collapse all calls to trap down to just one per
3285 // function to save on code size.
3286 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3287 TrapBB = createBasicBlock("trap");
3288 Builder.CreateCondBr(Checked, Cont, TrapBB);
3290 llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3291 TrapCall->setDoesNotReturn();
3292 TrapCall->setDoesNotThrow();
3293 Builder.CreateUnreachable();
3295 Builder.CreateCondBr(Checked, Cont, TrapBB);
3301 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
3302 llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3304 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3305 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3306 CGM.getCodeGenOpts().TrapFuncName);
3307 TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3313 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
3314 LValueBaseInfo *BaseInfo,
3315 TBAAAccessInfo *TBAAInfo) {
3316 assert(E->getType()->isArrayType() &&
3317 "Array to pointer decay must have array source type!");
3319 // Expressions of array type can't be bitfields or vector elements.
3320 LValue LV = EmitLValue(E);
3321 Address Addr = LV.getAddress();
3323 // If the array type was an incomplete type, we need to make sure
3324 // the decay ends up being the right type.
3325 llvm::Type *NewTy = ConvertType(E->getType());
3326 Addr = Builder.CreateElementBitCast(Addr, NewTy);
3328 // Note that VLA pointers are always decayed, so we don't need to do
3330 if (!E->getType()->isVariableArrayType()) {
3331 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3332 "Expected pointer to array");
3333 Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3336 // The result of this decay conversion points to an array element within the
3337 // base lvalue. However, since TBAA currently does not support representing
3338 // accesses to elements of member arrays, we conservatively represent accesses
3339 // to the pointee object as if it had no any base lvalue specified.
3340 // TODO: Support TBAA for member arrays.
3341 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
3342 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3343 if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3345 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3348 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3349 /// array to pointer, return the array subexpression.
3350 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3351 // If this isn't just an array->pointer decay, bail out.
3352 const auto *CE = dyn_cast<CastExpr>(E);
3353 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3356 // If this is a decay from variable width array, bail out.
3357 const Expr *SubExpr = CE->getSubExpr();
3358 if (SubExpr->getType()->isVariableArrayType())
3364 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
3366 ArrayRef<llvm::Value*> indices,
3370 const llvm::Twine &name = "arrayidx") {
3372 return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3373 CodeGenFunction::NotSubtraction, loc,
3376 return CGF.Builder.CreateGEP(ptr, indices, name);
3380 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
3382 CharUnits eltSize) {
3383 // If we have a constant index, we can use the exact offset of the
3384 // element we're accessing.
3385 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3386 CharUnits offset = constantIdx->getZExtValue() * eltSize;
3387 return arrayAlign.alignmentAtOffset(offset);
3389 // Otherwise, use the worst-case alignment for any element.
3391 return arrayAlign.alignmentOfArrayElement(eltSize);
3395 static QualType getFixedSizeElementType(const ASTContext &ctx,
3396 const VariableArrayType *vla) {
3399 eltType = vla->getElementType();
3400 } while ((vla = ctx.getAsVariableArrayType(eltType)));
3404 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
3405 ArrayRef<llvm::Value *> indices,
3406 QualType eltType, bool inbounds,
3407 bool signedIndices, SourceLocation loc,
3408 const llvm::Twine &name = "arrayidx") {
3409 // All the indices except that last must be zero.
3411 for (auto idx : indices.drop_back())
3412 assert(isa<llvm::ConstantInt>(idx) &&
3413 cast<llvm::ConstantInt>(idx)->isZero());
3416 // Determine the element size of the statically-sized base. This is
3417 // the thing that the indices are expressed in terms of.
3418 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3419 eltType = getFixedSizeElementType(CGF.getContext(), vla);
3422 // We can use that to compute the best alignment of the element.
3423 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3424 CharUnits eltAlign =
3425 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3427 llvm::Value *eltPtr;
3428 auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
3429 if (!CGF.IsInPreservedAIRegion || !LastIndex) {
3430 eltPtr = emitArraySubscriptGEP(
3431 CGF, addr.getPointer(), indices, inbounds, signedIndices,
3434 // Remember the original array subscript for bpf target
3435 unsigned idx = LastIndex->getZExtValue();
3436 eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getPointer(),
3441 return Address(eltPtr, eltAlign);
3444 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3446 // The index must always be an integer, which is not an aggregate. Emit it
3447 // in lexical order (this complexity is, sadly, required by C++17).
3448 llvm::Value *IdxPre =
3449 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3450 bool SignedIndices = false;
3451 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3453 if (E->getLHS() != E->getIdx()) {
3454 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3455 Idx = EmitScalarExpr(E->getIdx());
3458 QualType IdxTy = E->getIdx()->getType();
3459 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3460 SignedIndices |= IdxSigned;
3462 if (SanOpts.has(SanitizerKind::ArrayBounds))
3463 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3465 // Extend or truncate the index type to 32 or 64-bits.
3466 if (Promote && Idx->getType() != IntPtrTy)
3467 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3473 // If the base is a vector type, then we are forming a vector element lvalue
3474 // with this subscript.
3475 if (E->getBase()->getType()->isVectorType() &&
3476 !isa<ExtVectorElementExpr>(E->getBase())) {
3477 // Emit the vector as an lvalue to get its address.
3478 LValue LHS = EmitLValue(E->getBase());
3479 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3480 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3481 return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
3482 LHS.getBaseInfo(), TBAAAccessInfo());
3485 // All the other cases basically behave like simple offsetting.
3487 // Handle the extvector case we ignored above.
3488 if (isa<ExtVectorElementExpr>(E->getBase())) {
3489 LValue LV = EmitLValue(E->getBase());
3490 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3491 Address Addr = EmitExtVectorElementLValue(LV);
3493 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3494 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3495 SignedIndices, E->getExprLoc());
3496 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3497 CGM.getTBAAInfoForSubobject(LV, EltType));
3500 LValueBaseInfo EltBaseInfo;
3501 TBAAAccessInfo EltTBAAInfo;
3502 Address Addr = Address::invalid();
3503 if (const VariableArrayType *vla =
3504 getContext().getAsVariableArrayType(E->getType())) {
3505 // The base must be a pointer, which is not an aggregate. Emit
3506 // it. It needs to be emitted first in case it's what captures
3508 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3509 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3511 // The element count here is the total number of non-VLA elements.
3512 llvm::Value *numElements = getVLASize(vla).NumElts;
3514 // Effectively, the multiply by the VLA size is part of the GEP.
3515 // GEP indexes are signed, and scaling an index isn't permitted to
3516 // signed-overflow, so we use the same semantics for our explicit
3517 // multiply. We suppress this if overflow is not undefined behavior.
3518 if (getLangOpts().isSignedOverflowDefined()) {
3519 Idx = Builder.CreateMul(Idx, numElements);
3521 Idx = Builder.CreateNSWMul(Idx, numElements);
3524 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3525 !getLangOpts().isSignedOverflowDefined(),
3526 SignedIndices, E->getExprLoc());
3528 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3529 // Indexing over an interface, as in "NSString *P; P[4];"
3531 // Emit the base pointer.
3532 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3533 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3535 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3536 llvm::Value *InterfaceSizeVal =
3537 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3539 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3541 // We don't necessarily build correct LLVM struct types for ObjC
3542 // interfaces, so we can't rely on GEP to do this scaling
3543 // correctly, so we need to cast to i8*. FIXME: is this actually
3544 // true? A lot of other things in the fragile ABI would break...
3545 llvm::Type *OrigBaseTy = Addr.getType();
3546 Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3549 CharUnits EltAlign =
3550 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3551 llvm::Value *EltPtr =
3552 emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3553 SignedIndices, E->getExprLoc());
3554 Addr = Address(EltPtr, EltAlign);
3557 Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3558 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3559 // If this is A[i] where A is an array, the frontend will have decayed the
3560 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3561 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3562 // "gep x, i" here. Emit one "gep A, 0, i".
3563 assert(Array->getType()->isArrayType() &&
3564 "Array to pointer decay must have array source type!");
3566 // For simple multidimensional array indexing, set the 'accessed' flag for
3567 // better bounds-checking of the base expression.
3568 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3569 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3571 ArrayLV = EmitLValue(Array);
3572 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3574 // Propagate the alignment from the array itself to the result.
3575 Addr = emitArraySubscriptGEP(
3576 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3577 E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3579 EltBaseInfo = ArrayLV.getBaseInfo();
3580 EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3582 // The base must be a pointer; emit it with an estimate of its alignment.
3583 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3584 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3585 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3586 !getLangOpts().isSignedOverflowDefined(),
3587 SignedIndices, E->getExprLoc());
3590 LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3592 if (getLangOpts().ObjC &&
3593 getLangOpts().getGC() != LangOptions::NonGC) {
3594 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3595 setObjCGCLValueClass(getContext(), E, LV);
3600 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
3601 LValueBaseInfo &BaseInfo,
3602 TBAAAccessInfo &TBAAInfo,
3603 QualType BaseTy, QualType ElTy,
3604 bool IsLowerBound) {
3606 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3607 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3608 if (BaseTy->isArrayType()) {
3609 Address Addr = BaseLVal.getAddress();
3610 BaseInfo = BaseLVal.getBaseInfo();
3612 // If the array type was an incomplete type, we need to make sure
3613 // the decay ends up being the right type.
3614 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3615 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3617 // Note that VLA pointers are always decayed, so we don't need to do
3619 if (!BaseTy->isVariableArrayType()) {
3620 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3621 "Expected pointer to array");
3622 Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3625 return CGF.Builder.CreateElementBitCast(Addr,
3626 CGF.ConvertTypeForMem(ElTy));
3628 LValueBaseInfo TypeBaseInfo;
3629 TBAAAccessInfo TypeTBAAInfo;
3630 CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3632 BaseInfo.mergeForCast(TypeBaseInfo);
3633 TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3634 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3636 return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3639 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3640 bool IsLowerBound) {
3641 QualType BaseTy = OMPArraySectionExpr::getBaseOriginalType(E->getBase());
3642 QualType ResultExprTy;
3643 if (auto *AT = getContext().getAsArrayType(BaseTy))
3644 ResultExprTy = AT->getElementType();
3646 ResultExprTy = BaseTy->getPointeeType();
3647 llvm::Value *Idx = nullptr;
3648 if (IsLowerBound || E->getColonLoc().isInvalid()) {
3649 // Requesting lower bound or upper bound, but without provided length and
3650 // without ':' symbol for the default length -> length = 1.
3651 // Idx = LowerBound ?: 0;
3652 if (auto *LowerBound = E->getLowerBound()) {
3653 Idx = Builder.CreateIntCast(
3654 EmitScalarExpr(LowerBound), IntPtrTy,
3655 LowerBound->getType()->hasSignedIntegerRepresentation());
3657 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3659 // Try to emit length or lower bound as constant. If this is possible, 1
3660 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3661 // IR (LB + Len) - 1.
3662 auto &C = CGM.getContext();
3663 auto *Length = E->getLength();
3664 llvm::APSInt ConstLength;
3666 // Idx = LowerBound + Length - 1;
3667 if (Length->isIntegerConstantExpr(ConstLength, C)) {
3668 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3671 auto *LowerBound = E->getLowerBound();
3672 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3673 if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3674 ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3675 LowerBound = nullptr;
3679 else if (!LowerBound)
3682 if (Length || LowerBound) {
3683 auto *LowerBoundVal =
3685 ? Builder.CreateIntCast(
3686 EmitScalarExpr(LowerBound), IntPtrTy,
3687 LowerBound->getType()->hasSignedIntegerRepresentation())
3688 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3691 ? Builder.CreateIntCast(
3692 EmitScalarExpr(Length), IntPtrTy,
3693 Length->getType()->hasSignedIntegerRepresentation())
3694 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3695 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3697 !getLangOpts().isSignedOverflowDefined());
3698 if (Length && LowerBound) {
3699 Idx = Builder.CreateSub(
3700 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3701 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3704 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3706 // Idx = ArraySize - 1;
3707 QualType ArrayTy = BaseTy->isPointerType()
3708 ? E->getBase()->IgnoreParenImpCasts()->getType()
3710 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3711 Length = VAT->getSizeExpr();
3712 if (Length->isIntegerConstantExpr(ConstLength, C))
3715 auto *CAT = C.getAsConstantArrayType(ArrayTy);
3716 ConstLength = CAT->getSize();
3719 auto *LengthVal = Builder.CreateIntCast(
3720 EmitScalarExpr(Length), IntPtrTy,
3721 Length->getType()->hasSignedIntegerRepresentation());
3722 Idx = Builder.CreateSub(
3723 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3724 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3726 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3728 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3734 Address EltPtr = Address::invalid();
3735 LValueBaseInfo BaseInfo;
3736 TBAAAccessInfo TBAAInfo;
3737 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3738 // The base must be a pointer, which is not an aggregate. Emit
3739 // it. It needs to be emitted first in case it's what captures
3742 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3743 BaseTy, VLA->getElementType(), IsLowerBound);
3744 // The element count here is the total number of non-VLA elements.
3745 llvm::Value *NumElements = getVLASize(VLA).NumElts;
3747 // Effectively, the multiply by the VLA size is part of the GEP.
3748 // GEP indexes are signed, and scaling an index isn't permitted to
3749 // signed-overflow, so we use the same semantics for our explicit
3750 // multiply. We suppress this if overflow is not undefined behavior.
3751 if (getLangOpts().isSignedOverflowDefined())
3752 Idx = Builder.CreateMul(Idx, NumElements);
3754 Idx = Builder.CreateNSWMul(Idx, NumElements);
3755 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3756 !getLangOpts().isSignedOverflowDefined(),
3757 /*signedIndices=*/false, E->getExprLoc());
3758 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3759 // If this is A[i] where A is an array, the frontend will have decayed the
3760 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3761 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3762 // "gep x, i" here. Emit one "gep A, 0, i".
3763 assert(Array->getType()->isArrayType() &&
3764 "Array to pointer decay must have array source type!");
3766 // For simple multidimensional array indexing, set the 'accessed' flag for
3767 // better bounds-checking of the base expression.
3768 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3769 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3771 ArrayLV = EmitLValue(Array);
3773 // Propagate the alignment from the array itself to the result.
3774 EltPtr = emitArraySubscriptGEP(
3775 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3776 ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3777 /*signedIndices=*/false, E->getExprLoc());
3778 BaseInfo = ArrayLV.getBaseInfo();
3779 TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3781 Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3782 TBAAInfo, BaseTy, ResultExprTy,
3784 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3785 !getLangOpts().isSignedOverflowDefined(),
3786 /*signedIndices=*/false, E->getExprLoc());
3789 return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3792 LValue CodeGenFunction::
3793 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
3794 // Emit the base vector as an l-value.
3797 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3799 // If it is a pointer to a vector, emit the address and form an lvalue with
3801 LValueBaseInfo BaseInfo;
3802 TBAAAccessInfo TBAAInfo;
3803 Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3804 const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3805 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3806 Base.getQuals().removeObjCGCAttr();
3807 } else if (E->getBase()->isGLValue()) {
3808 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3809 // emit the base as an lvalue.
3810 assert(E->getBase()->getType()->isVectorType());
3811 Base = EmitLValue(E->getBase());
3813 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3814 assert(E->getBase()->getType()->isVectorType() &&
3815 "Result must be a vector");
3816 llvm::Value *Vec = EmitScalarExpr(E->getBase());
3818 // Store the vector to memory (because LValue wants an address).
3819 Address VecMem = CreateMemTemp(E->getBase()->getType());
3820 Builder.CreateStore(Vec, VecMem);
3821 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3822 AlignmentSource::Decl);
3826 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
3828 // Encode the element access list into a vector of unsigned indices.
3829 SmallVector<uint32_t, 4> Indices;
3830 E->getEncodedElementAccess(Indices);
3832 if (Base.isSimple()) {
3833 llvm::Constant *CV =
3834 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3835 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3836 Base.getBaseInfo(), TBAAAccessInfo());
3838 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3840 llvm::Constant *BaseElts = Base.getExtVectorElts();
3841 SmallVector<llvm::Constant *, 4> CElts;
3843 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3844 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3845 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3846 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
3847 Base.getBaseInfo(), TBAAAccessInfo());
3850 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
3851 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3852 EmitIgnoredExpr(E->getBase());
3853 return EmitDeclRefLValue(DRE);
3856 Expr *BaseExpr = E->getBase();
3857 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3860 LValueBaseInfo BaseInfo;
3861 TBAAAccessInfo TBAAInfo;
3862 Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3863 QualType PtrTy = BaseExpr->getType()->getPointeeType();
3864 SanitizerSet SkippedChecks;
3865 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3867 SkippedChecks.set(SanitizerKind::Alignment, true);
3868 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3869 SkippedChecks.set(SanitizerKind::Null, true);
3870 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3871 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3872 BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3874 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3876 NamedDecl *ND = E->getMemberDecl();
3877 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3878 LValue LV = EmitLValueForField(BaseLV, Field);
3879 setObjCGCLValueClass(getContext(), E, LV);
3883 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3884 return EmitFunctionDeclLValue(*this, E, FD);
3886 llvm_unreachable("Unhandled member declaration!");
3889 /// Given that we are currently emitting a lambda, emit an l-value for
3890 /// one of its members.
3891 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
3892 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3893 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3894 QualType LambdaTagType =
3895 getContext().getTagDeclType(Field->getParent());
3896 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3897 return EmitLValueForField(LambdaLV, Field);
3900 /// Get the field index in the debug info. The debug info structure/union
3901 /// will ignore the unnamed bitfields.
3902 unsigned CodeGenFunction::getDebugInfoFIndex(const RecordDecl *Rec,
3903 unsigned FieldIndex) {
3904 unsigned I = 0, Skipped = 0;
3906 for (auto F : Rec->getDefinition()->fields()) {
3907 if (I == FieldIndex)
3909 if (F->isUnnamedBitfield())
3914 return FieldIndex - Skipped;
3917 /// Get the address of a zero-sized field within a record. The resulting
3918 /// address doesn't necessarily have the right type.
3919 static Address emitAddrOfZeroSizeField(CodeGenFunction &CGF, Address Base,
3920 const FieldDecl *Field) {
3921 CharUnits Offset = CGF.getContext().toCharUnitsFromBits(
3922 CGF.getContext().getFieldOffset(Field));
3923 if (Offset.isZero())
3925 Base = CGF.Builder.CreateElementBitCast(Base, CGF.Int8Ty);
3926 return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset);
3929 /// Drill down to the storage of a field without walking into
3930 /// reference types.
3932 /// The resulting address doesn't necessarily have the right type.
3933 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
3934 const FieldDecl *field) {
3935 if (field->isZeroSize(CGF.getContext()))
3936 return emitAddrOfZeroSizeField(CGF, base, field);
3938 const RecordDecl *rec = field->getParent();
3941 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3943 return CGF.Builder.CreateStructGEP(base, idx, field->getName());
3946 static Address emitPreserveStructAccess(CodeGenFunction &CGF, Address base,
3947 const FieldDecl *field) {
3948 const RecordDecl *rec = field->getParent();
3949 llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateRecordType(
3950 CGF.getContext().getRecordType(rec), rec->getLocation());
3953 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3955 return CGF.Builder.CreatePreserveStructAccessIndex(
3956 base, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
3959 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3960 const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3964 if (RD->isDynamicClass())
3967 for (const auto &Base : RD->bases())
3968 if (hasAnyVptr(Base.getType(), Context))
3971 for (const FieldDecl *Field : RD->fields())
3972 if (hasAnyVptr(Field->getType(), Context))
3978 LValue CodeGenFunction::EmitLValueForField(LValue base,
3979 const FieldDecl *field) {
3980 LValueBaseInfo BaseInfo = base.getBaseInfo();
3982 if (field->isBitField()) {
3983 const CGRecordLayout &RL =
3984 CGM.getTypes().getCGRecordLayout(field->getParent());
3985 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3986 Address Addr = base.getAddress();
3987 unsigned Idx = RL.getLLVMFieldNo(field);
3989 // For structs, we GEP to the field that the record layout suggests.
3990 Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
3991 // Get the access type.
3992 llvm::Type *FieldIntTy =
3993 llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3994 if (Addr.getElementType() != FieldIntTy)
3995 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3997 QualType fieldType =
3998 field->getType().withCVRQualifiers(base.getVRQualifiers());
3999 // TODO: Support TBAA for bit fields.
4000 LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
4001 return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
4005 // Fields of may-alias structures are may-alias themselves.
4006 // FIXME: this should get propagated down through anonymous structs
4008 QualType FieldType = field->getType();
4009 const RecordDecl *rec = field->getParent();
4010 AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
4011 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
4012 TBAAAccessInfo FieldTBAAInfo;
4013 if (base.getTBAAInfo().isMayAlias() ||
4014 rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
4015 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4016 } else if (rec->isUnion()) {
4017 // TODO: Support TBAA for unions.
4018 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4020 // If no base type been assigned for the base access, then try to generate
4021 // one for this base lvalue.
4022 FieldTBAAInfo = base.getTBAAInfo();
4023 if (!FieldTBAAInfo.BaseType) {
4024 FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
4025 assert(!FieldTBAAInfo.Offset &&
4026 "Nonzero offset for an access with no base type!");
4029 // Adjust offset to be relative to the base type.
4030 const ASTRecordLayout &Layout =
4031 getContext().getASTRecordLayout(field->getParent());
4032 unsigned CharWidth = getContext().getCharWidth();
4033 if (FieldTBAAInfo.BaseType)
4034 FieldTBAAInfo.Offset +=
4035 Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
4037 // Update the final access type and size.
4038 FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
4039 FieldTBAAInfo.Size =
4040 getContext().getTypeSizeInChars(FieldType).getQuantity();
4043 Address addr = base.getAddress();
4044 if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
4045 if (CGM.getCodeGenOpts().StrictVTablePointers &&
4046 ClassDef->isDynamicClass()) {
4047 // Getting to any field of dynamic object requires stripping dynamic
4048 // information provided by invariant.group. This is because accessing
4049 // fields may leak the real address of dynamic object, which could result
4050 // in miscompilation when leaked pointer would be compared.
4051 auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
4052 addr = Address(stripped, addr.getAlignment());
4056 unsigned RecordCVR = base.getVRQualifiers();
4057 if (rec->isUnion()) {
4058 // For unions, there is no pointer adjustment.
4059 assert(!FieldType->isReferenceType() && "union has reference member");
4060 if (CGM.getCodeGenOpts().StrictVTablePointers &&
4061 hasAnyVptr(FieldType, getContext()))
4062 // Because unions can easily skip invariant.barriers, we need to add
4063 // a barrier every time CXXRecord field with vptr is referenced.
4064 addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
4065 addr.getAlignment());
4067 if (IsInPreservedAIRegion) {
4068 // Remember the original union field index
4069 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4070 getContext().getRecordType(rec), rec->getLocation());
4072 Builder.CreatePreserveUnionAccessIndex(
4073 addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
4074 addr.getAlignment());
4078 if (!IsInPreservedAIRegion)
4079 // For structs, we GEP to the field that the record layout suggests.
4080 addr = emitAddrOfFieldStorage(*this, addr, field);
4082 // Remember the original struct field index
4083 addr = emitPreserveStructAccess(*this, addr, field);
4085 // If this is a reference field, load the reference right now.
4086 if (FieldType->isReferenceType()) {
4087 LValue RefLVal = MakeAddrLValue(addr, FieldType, FieldBaseInfo,
4089 if (RecordCVR & Qualifiers::Volatile)
4090 RefLVal.getQuals().addVolatile();
4091 addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
4093 // Qualifiers on the struct don't apply to the referencee.
4095 FieldType = FieldType->getPointeeType();
4099 // Make sure that the address is pointing to the right type. This is critical
4100 // for both unions and structs. A union needs a bitcast, a struct element
4101 // will need a bitcast if the LLVM type laid out doesn't match the desired
4103 addr = Builder.CreateElementBitCast(
4104 addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4106 if (field->hasAttr<AnnotateAttr>())
4107 addr = EmitFieldAnnotations(field, addr);
4109 LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4110 LV.getQuals().addCVRQualifiers(RecordCVR);
4112 // __weak attribute on a field is ignored.
4113 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
4114 LV.getQuals().removeObjCGCAttr();
4120 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
4121 const FieldDecl *Field) {
4122 QualType FieldType = Field->getType();
4124 if (!FieldType->isReferenceType())
4125 return EmitLValueForField(Base, Field);
4127 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
4129 // Make sure that the address is pointing to the right type.
4130 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
4131 V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
4133 // TODO: Generate TBAA information that describes this access as a structure
4134 // member access and not just an access to an object of the field's type. This
4135 // should be similar to what we do in EmitLValueForField().
4136 LValueBaseInfo BaseInfo = Base.getBaseInfo();
4137 AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
4138 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
4139 return MakeAddrLValue(V, FieldType, FieldBaseInfo,
4140 CGM.getTBAAInfoForSubobject(Base, FieldType));
4143 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
4144 if (E->isFileScope()) {
4145 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
4146 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
4148 if (E->getType()->isVariablyModifiedType())
4149 // make sure to emit the VLA size.
4150 EmitVariablyModifiedType(E->getType());
4152 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4153 const Expr *InitExpr = E->getInitializer();
4154 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4156 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4162 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
4163 if (!E->isGLValue())
4164 // Initializing an aggregate temporary in C++11: T{...}.
4165 return EmitAggExprToLValue(E);
4167 // An lvalue initializer list must be initializing a reference.
4168 assert(E->isTransparent() && "non-transparent glvalue init list");
4169 return EmitLValue(E->getInit(0));
4172 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4173 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4174 /// LValue is returned and the current block has been terminated.
4175 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
4176 const Expr *Operand) {
4177 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4178 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4182 return CGF.EmitLValue(Operand);
4185 LValue CodeGenFunction::
4186 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
4187 if (!expr->isGLValue()) {
4188 // ?: here should be an aggregate.
4189 assert(hasAggregateEvaluationKind(expr->getType()) &&
4190 "Unexpected conditional operator!");
4191 return EmitAggExprToLValue(expr);
4194 OpaqueValueMapping binding(*this, expr);
4196 const Expr *condExpr = expr->getCond();
4198 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4199 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4200 if (!CondExprBool) std::swap(live, dead);
4202 if (!ContainsLabel(dead)) {
4203 // If the true case is live, we need to track its region.
4205 incrementProfileCounter(expr);
4206 return EmitLValue(live);
4210 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4211 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4212 llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4214 ConditionalEvaluation eval(*this);
4215 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4217 // Any temporaries created here are conditional.
4218 EmitBlock(lhsBlock);
4219 incrementProfileCounter(expr);
4221 Optional<LValue> lhs =
4222 EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4225 if (lhs && !lhs->isSimple())
4226 return EmitUnsupportedLValue(expr, "conditional operator");
4228 lhsBlock = Builder.GetInsertBlock();
4230 Builder.CreateBr(contBlock);
4232 // Any temporaries created here are conditional.
4233 EmitBlock(rhsBlock);
4235 Optional<LValue> rhs =
4236 EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4238 if (rhs && !rhs->isSimple())
4239 return EmitUnsupportedLValue(expr, "conditional operator");
4240 rhsBlock = Builder.GetInsertBlock();
4242 EmitBlock(contBlock);
4245 llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
4247 phi->addIncoming(lhs->getPointer(), lhsBlock);
4248 phi->addIncoming(rhs->getPointer(), rhsBlock);
4249 Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4250 AlignmentSource alignSource =
4251 std::max(lhs->getBaseInfo().getAlignmentSource(),
4252 rhs->getBaseInfo().getAlignmentSource());
4253 TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForConditionalOperator(
4254 lhs->getTBAAInfo(), rhs->getTBAAInfo());
4255 return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4258 assert((lhs || rhs) &&
4259 "both operands of glvalue conditional are throw-expressions?");
4260 return lhs ? *lhs : *rhs;
4264 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4265 /// type. If the cast is to a reference, we can have the usual lvalue result,
4266 /// otherwise if a cast is needed by the code generator in an lvalue context,
4267 /// then it must mean that we need the address of an aggregate in order to
4268 /// access one of its members. This can happen for all the reasons that casts
4269 /// are permitted with aggregate result, including noop aggregate casts, and
4270 /// cast from scalar to union.
4271 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
4272 switch (E->getCastKind()) {
4275 case CK_LValueToRValueBitCast:
4276 case CK_ArrayToPointerDecay:
4277 case CK_FunctionToPointerDecay:
4278 case CK_NullToMemberPointer:
4279 case CK_NullToPointer:
4280 case CK_IntegralToPointer:
4281 case CK_PointerToIntegral:
4282 case CK_PointerToBoolean:
4283 case CK_VectorSplat:
4284 case CK_IntegralCast:
4285 case CK_BooleanToSignedIntegral:
4286 case CK_IntegralToBoolean:
4287 case CK_IntegralToFloating:
4288 case CK_FloatingToIntegral:
4289 case CK_FloatingToBoolean:
4290 case CK_FloatingCast:
4291 case CK_FloatingRealToComplex:
4292 case CK_FloatingComplexToReal:
4293 case CK_FloatingComplexToBoolean:
4294 case CK_FloatingComplexCast:
4295 case CK_FloatingComplexToIntegralComplex:
4296 case CK_IntegralRealToComplex:
4297 case CK_IntegralComplexToReal:
4298 case CK_IntegralComplexToBoolean:
4299 case CK_IntegralComplexCast:
4300 case CK_IntegralComplexToFloatingComplex:
4301 case CK_DerivedToBaseMemberPointer:
4302 case CK_BaseToDerivedMemberPointer:
4303 case CK_MemberPointerToBoolean:
4304 case CK_ReinterpretMemberPointer:
4305 case CK_AnyPointerToBlockPointerCast:
4306 case CK_ARCProduceObject:
4307 case CK_ARCConsumeObject:
4308 case CK_ARCReclaimReturnedObject:
4309 case CK_ARCExtendBlockObject:
4310 case CK_CopyAndAutoreleaseBlockObject:
4311 case CK_IntToOCLSampler:
4312 case CK_FixedPointCast:
4313 case CK_FixedPointToBoolean:
4314 case CK_FixedPointToIntegral:
4315 case CK_IntegralToFixedPoint:
4316 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4319 llvm_unreachable("dependent cast kind in IR gen!");
4321 case CK_BuiltinFnToFnPtr:
4322 llvm_unreachable("builtin functions are handled elsewhere");
4324 // These are never l-values; just use the aggregate emission code.
4325 case CK_NonAtomicToAtomic:
4326 case CK_AtomicToNonAtomic:
4327 return EmitAggExprToLValue(E);
4330 LValue LV = EmitLValue(E->getSubExpr());
4331 Address V = LV.getAddress();
4332 const auto *DCE = cast<CXXDynamicCastExpr>(E);
4333 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4336 case CK_ConstructorConversion:
4337 case CK_UserDefinedConversion:
4338 case CK_CPointerToObjCPointerCast:
4339 case CK_BlockPointerToObjCPointerCast:
4341 case CK_LValueToRValue:
4342 return EmitLValue(E->getSubExpr());
4344 case CK_UncheckedDerivedToBase:
4345 case CK_DerivedToBase: {
4346 const RecordType *DerivedClassTy =
4347 E->getSubExpr()->getType()->getAs<RecordType>();
4348 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4350 LValue LV = EmitLValue(E->getSubExpr());
4351 Address This = LV.getAddress();
4353 // Perform the derived-to-base conversion
4354 Address Base = GetAddressOfBaseClass(
4355 This, DerivedClassDecl, E->path_begin(), E->path_end(),
4356 /*NullCheckValue=*/false, E->getExprLoc());
4358 // TODO: Support accesses to members of base classes in TBAA. For now, we
4359 // conservatively pretend that the complete object is of the base class
4361 return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4362 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4365 return EmitAggExprToLValue(E);
4366 case CK_BaseToDerived: {
4367 const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
4368 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4370 LValue LV = EmitLValue(E->getSubExpr());
4372 // Perform the base-to-derived conversion
4374 GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
4375 E->path_begin(), E->path_end(),
4376 /*NullCheckValue=*/false);
4378 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4379 // performed and the object is not of the derived type.
4380 if (sanitizePerformTypeCheck())
4381 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
4382 Derived.getPointer(), E->getType());
4384 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4385 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4386 /*MayBeNull=*/false, CFITCK_DerivedCast,
4389 return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4390 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4392 case CK_LValueBitCast: {
4393 // This must be a reinterpret_cast (or c-style equivalent).
4394 const auto *CE = cast<ExplicitCastExpr>(E);
4396 CGM.EmitExplicitCastExprType(CE, this);
4397 LValue LV = EmitLValue(E->getSubExpr());
4398 Address V = Builder.CreateBitCast(LV.getAddress(),
4399 ConvertType(CE->getTypeAsWritten()));
4401 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4402 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4403 /*MayBeNull=*/false, CFITCK_UnrelatedCast,
4406 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4407 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4409 case CK_AddressSpaceConversion: {
4410 LValue LV = EmitLValue(E->getSubExpr());
4411 QualType DestTy = getContext().getPointerType(E->getType());
4412 llvm::Value *V = getTargetHooks().performAddrSpaceCast(
4413 *this, LV.getPointer(), E->getSubExpr()->getType().getAddressSpace(),
4414 E->getType().getAddressSpace(), ConvertType(DestTy));
4415 return MakeAddrLValue(Address(V, LV.getAddress().getAlignment()),
4416 E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
4418 case CK_ObjCObjectLValueCast: {
4419 LValue LV = EmitLValue(E->getSubExpr());
4420 Address V = Builder.CreateElementBitCast(LV.getAddress(),
4421 ConvertType(E->getType()));
4422 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4423 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4425 case CK_ZeroToOCLOpaqueType:
4426 llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
4429 llvm_unreachable("Unhandled lvalue cast kind?");
4432 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
4433 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
4434 return getOrCreateOpaqueLValueMapping(e);
4438 CodeGenFunction::getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e) {
4439 assert(OpaqueValueMapping::shouldBindAsLValue(e));
4441 llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4442 it = OpaqueLValues.find(e);
4444 if (it != OpaqueLValues.end())
4447 assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4448 return EmitLValue(e->getSourceExpr());
4452 CodeGenFunction::getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e) {
4453 assert(!OpaqueValueMapping::shouldBindAsLValue(e));
4455 llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4456 it = OpaqueRValues.find(e);
4458 if (it != OpaqueRValues.end())
4461 assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4462 return EmitAnyExpr(e->getSourceExpr());
4465 RValue CodeGenFunction::EmitRValueForField(LValue LV,
4466 const FieldDecl *FD,
4467 SourceLocation Loc) {
4468 QualType FT = FD->getType();
4469 LValue FieldLV = EmitLValueForField(LV, FD);
4470 switch (getEvaluationKind(FT)) {
4472 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4474 return FieldLV.asAggregateRValue();
4476 // This routine is used to load fields one-by-one to perform a copy, so
4477 // don't load reference fields.
4478 if (FD->getType()->isReferenceType())
4479 return RValue::get(FieldLV.getPointer());
4480 return EmitLoadOfLValue(FieldLV, Loc);
4482 llvm_unreachable("bad evaluation kind");
4485 //===--------------------------------------------------------------------===//
4486 // Expression Emission
4487 //===--------------------------------------------------------------------===//
4489 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
4490 ReturnValueSlot ReturnValue) {
4491 // Builtins never have block type.
4492 if (E->getCallee()->getType()->isBlockPointerType())
4493 return EmitBlockCallExpr(E, ReturnValue);
4495 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4496 return EmitCXXMemberCallExpr(CE, ReturnValue);
4498 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4499 return EmitCUDAKernelCallExpr(CE, ReturnValue);
4501 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4502 if (const CXXMethodDecl *MD =
4503 dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4504 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4506 CGCallee callee = EmitCallee(E->getCallee());
4508 if (callee.isBuiltin()) {
4509 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4513 if (callee.isPseudoDestructor()) {
4514 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
4517 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4520 /// Emit a CallExpr without considering whether it might be a subclass.
4521 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
4522 ReturnValueSlot ReturnValue) {
4523 CGCallee Callee = EmitCallee(E->getCallee());
4524 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4527 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
4528 if (auto builtinID = FD->getBuiltinID()) {
4529 return CGCallee::forBuiltin(builtinID, FD);
4532 llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4533 return CGCallee::forDirect(calleePtr, GlobalDecl(FD));
4536 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
4537 E = E->IgnoreParens();
4539 // Look through function-to-pointer decay.
4540 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4541 if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4542 ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4543 return EmitCallee(ICE->getSubExpr());
4546 // Resolve direct calls.
4547 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4548 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4549 return EmitDirectCallee(*this, FD);
4551 } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4552 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4553 EmitIgnoredExpr(ME->getBase());
4554 return EmitDirectCallee(*this, FD);
4557 // Look through template substitutions.
4558 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4559 return EmitCallee(NTTP->getReplacement());
4561 // Treat pseudo-destructor calls differently.
4562 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4563 return CGCallee::forPseudoDestructor(PDE);
4566 // Otherwise, we have an indirect reference.
4567 llvm::Value *calleePtr;
4568 QualType functionType;
4569 if (auto ptrType = E->getType()->getAs<PointerType>()) {
4570 calleePtr = EmitScalarExpr(E);
4571 functionType = ptrType->getPointeeType();
4573 functionType = E->getType();
4574 calleePtr = EmitLValue(E).getPointer();
4576 assert(functionType->isFunctionType());
4579 if (const auto *VD =
4580 dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
4581 GD = GlobalDecl(VD);
4583 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
4584 CGCallee callee(calleeInfo, calleePtr);
4588 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
4589 // Comma expressions just emit their LHS then their RHS as an l-value.
4590 if (E->getOpcode() == BO_Comma) {
4591 EmitIgnoredExpr(E->getLHS());
4592 EnsureInsertPoint();
4593 return EmitLValue(E->getRHS());
4596 if (E->getOpcode() == BO_PtrMemD ||
4597 E->getOpcode() == BO_PtrMemI)
4598 return EmitPointerToDataMemberBinaryExpr(E);
4600 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4602 // Note that in all of these cases, __block variables need the RHS
4603 // evaluated first just in case the variable gets moved by the RHS.
4605 switch (getEvaluationKind(E->getType())) {
4607 switch (E->getLHS()->getType().getObjCLifetime()) {
4608 case Qualifiers::OCL_Strong:
4609 return EmitARCStoreStrong(E, /*ignored*/ false).first;
4611 case Qualifiers::OCL_Autoreleasing:
4612 return EmitARCStoreAutoreleasing(E).first;
4614 // No reason to do any of these differently.
4615 case Qualifiers::OCL_None:
4616 case Qualifiers::OCL_ExplicitNone:
4617 case Qualifiers::OCL_Weak:
4621 RValue RV = EmitAnyExpr(E->getRHS());
4622 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
4624 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
4625 EmitStoreThroughLValue(RV, LV);
4630 return EmitComplexAssignmentLValue(E);
4633 return EmitAggExprToLValue(E);
4635 llvm_unreachable("bad evaluation kind");
4638 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
4639 RValue RV = EmitCallExpr(E);
4642 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4643 AlignmentSource::Decl);
4645 assert(E->getCallReturnType(getContext())->isReferenceType() &&
4646 "Can't have a scalar return unless the return type is a "
4649 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4652 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
4653 // FIXME: This shouldn't require another copy.
4654 return EmitAggExprToLValue(E);
4657 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
4658 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
4659 && "binding l-value to type which needs a temporary");
4660 AggValueSlot Slot = CreateAggTemp(E->getType());
4661 EmitCXXConstructExpr(E, Slot);
4662 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4666 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
4667 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
4670 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
4671 return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
4672 ConvertType(E->getType()));
4675 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
4676 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4677 AlignmentSource::Decl);
4681 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
4682 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4683 Slot.setExternallyDestructed();
4684 EmitAggExpr(E->getSubExpr(), Slot);
4685 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4686 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4689 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
4690 RValue RV = EmitObjCMessageExpr(E);
4693 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4694 AlignmentSource::Decl);
4696 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4697 "Can't have a scalar return unless the return type is a "
4700 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4703 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
4705 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
4706 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4709 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
4710 const ObjCIvarDecl *Ivar) {
4711 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4714 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
4715 llvm::Value *BaseValue,
4716 const ObjCIvarDecl *Ivar,
4717 unsigned CVRQualifiers) {
4718 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4719 Ivar, CVRQualifiers);
4722 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
4723 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4724 llvm::Value *BaseValue = nullptr;
4725 const Expr *BaseExpr = E->getBase();
4726 Qualifiers BaseQuals;
4729 BaseValue = EmitScalarExpr(BaseExpr);
4730 ObjectTy = BaseExpr->getType()->getPointeeType();
4731 BaseQuals = ObjectTy.getQualifiers();
4733 LValue BaseLV = EmitLValue(BaseExpr);
4734 BaseValue = BaseLV.getPointer();
4735 ObjectTy = BaseExpr->getType();
4736 BaseQuals = ObjectTy.getQualifiers();
4740 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4741 BaseQuals.getCVRQualifiers());
4742 setObjCGCLValueClass(getContext(), E, LV);
4746 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
4747 // Can only get l-value for message expression returning aggregate type
4748 RValue RV = EmitAnyExprToTemp(E);
4749 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4750 AlignmentSource::Decl);
4753 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4754 const CallExpr *E, ReturnValueSlot ReturnValue,
4755 llvm::Value *Chain) {
4756 // Get the actual function type. The callee type will always be a pointer to
4757 // function type or a block pointer type.
4758 assert(CalleeType->isFunctionPointerType() &&
4759 "Call must have function pointer type!");
4761 const Decl *TargetDecl =
4762 OrigCallee.getAbstractInfo().getCalleeDecl().getDecl();
4764 CalleeType = getContext().getCanonicalType(CalleeType);
4766 auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
4768 CGCallee Callee = OrigCallee;
4770 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4771 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4772 if (llvm::Constant *PrefixSig =
4773 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
4774 SanitizerScope SanScope(this);
4775 // Remove any (C++17) exception specifications, to allow calling e.g. a
4776 // noexcept function through a non-noexcept pointer.
4778 getContext().getFunctionTypeWithExceptionSpec(PointeeType, EST_None);
4779 llvm::Constant *FTRTTIConst =
4780 CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
4781 llvm::Type *PrefixStructTyElems[] = {PrefixSig->getType(), Int32Ty};
4782 llvm::StructType *PrefixStructTy = llvm::StructType::get(
4783 CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4785 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4787 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4788 CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4789 llvm::Value *CalleeSigPtr =
4790 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4791 llvm::Value *CalleeSig =
4792 Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4793 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4795 llvm::BasicBlock *Cont = createBasicBlock("cont");
4796 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4797 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4799 EmitBlock(TypeCheck);
4800 llvm::Value *CalleeRTTIPtr =
4801 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4802 llvm::Value *CalleeRTTIEncoded =
4803 Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4804 llvm::Value *CalleeRTTI =
4805 DecodeAddrUsedInPrologue(CalleePtr, CalleeRTTIEncoded);
4806 llvm::Value *CalleeRTTIMatch =
4807 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4808 llvm::Constant *StaticData[] = {EmitCheckSourceLocation(E->getBeginLoc()),
4809 EmitCheckTypeDescriptor(CalleeType)};
4810 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4811 SanitizerHandler::FunctionTypeMismatch, StaticData,
4812 {CalleePtr, CalleeRTTI, FTRTTIConst});
4814 Builder.CreateBr(Cont);
4819 const auto *FnType = cast<FunctionType>(PointeeType);
4821 // If we are checking indirect calls and this call is indirect, check that the
4822 // function pointer is a member of the bit set for the function type.
4823 if (SanOpts.has(SanitizerKind::CFIICall) &&
4824 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4825 SanitizerScope SanScope(this);
4826 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4829 if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
4830 MD = CGM.CreateMetadataIdentifierGeneralized(QualType(FnType, 0));
4832 MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4834 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4836 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4837 llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4838 llvm::Value *TypeTest = Builder.CreateCall(
4839 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4841 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4842 llvm::Constant *StaticData[] = {
4843 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4844 EmitCheckSourceLocation(E->getBeginLoc()),
4845 EmitCheckTypeDescriptor(QualType(FnType, 0)),
4847 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4848 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4849 CastedCallee, StaticData);
4851 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4852 SanitizerHandler::CFICheckFail, StaticData,
4853 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4859 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
4860 CGM.getContext().VoidPtrTy);
4862 // C++17 requires that we evaluate arguments to a call using assignment syntax
4863 // right-to-left, and that we evaluate arguments to certain other operators
4864 // left-to-right. Note that we allow this to override the order dictated by
4865 // the calling convention on the MS ABI, which means that parameter
4866 // destruction order is not necessarily reverse construction order.
4867 // FIXME: Revisit this based on C++ committee response to unimplementability.
4868 EvaluationOrder Order = EvaluationOrder::Default;
4869 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4870 if (OCE->isAssignmentOp())
4871 Order = EvaluationOrder::ForceRightToLeft;
4873 switch (OCE->getOperator()) {
4875 case OO_GreaterGreater:
4880 Order = EvaluationOrder::ForceLeftToRight;
4888 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4889 E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4891 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
4892 Args, FnType, /*ChainCall=*/Chain);
4895 // If the expression that denotes the called function has a type
4896 // that does not include a prototype, [the default argument
4897 // promotions are performed]. If the number of arguments does not
4898 // equal the number of parameters, the behavior is undefined. If
4899 // the function is defined with a type that includes a prototype,
4900 // and either the prototype ends with an ellipsis (, ...) or the
4901 // types of the arguments after promotion are not compatible with
4902 // the types of the parameters, the behavior is undefined. If the
4903 // function is defined with a type that does not include a
4904 // prototype, and the types of the arguments after promotion are
4905 // not compatible with those of the parameters after promotion,
4906 // the behavior is undefined [except in some trivial cases].
4907 // That is, in the general case, we should assume that a call
4908 // through an unprototyped function type works like a *non-variadic*
4909 // call. The way we make this work is to cast to the exact type
4910 // of the promoted arguments.
4912 // Chain calls use this same code path to add the invisible chain parameter
4913 // to the function type.
4914 if (isa<FunctionNoProtoType>(FnType) || Chain) {
4915 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4916 CalleeTy = CalleeTy->getPointerTo();
4918 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4919 CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
4920 Callee.setFunctionPointer(CalleePtr);
4923 llvm::CallBase *CallOrInvoke = nullptr;
4924 RValue Call = EmitCall(FnInfo, Callee, ReturnValue, Args, &CallOrInvoke,
4927 // Generate function declaration DISuprogram in order to be used
4928 // in debug info about call sites.
4929 if (CGDebugInfo *DI = getDebugInfo()) {
4930 if (auto *CalleeDecl = dyn_cast_or_null<FunctionDecl>(TargetDecl))
4931 DI->EmitFuncDeclForCallSite(CallOrInvoke, QualType(FnType, 0),
4938 LValue CodeGenFunction::
4939 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
4940 Address BaseAddr = Address::invalid();
4941 if (E->getOpcode() == BO_PtrMemI) {
4942 BaseAddr = EmitPointerWithAlignment(E->getLHS());
4944 BaseAddr = EmitLValue(E->getLHS()).getAddress();
4947 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4949 const MemberPointerType *MPT
4950 = E->getRHS()->getType()->getAs<MemberPointerType>();
4952 LValueBaseInfo BaseInfo;
4953 TBAAAccessInfo TBAAInfo;
4954 Address MemberAddr =
4955 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo,
4958 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo);
4961 /// Given the address of a temporary variable, produce an r-value of
4963 RValue CodeGenFunction::convertTempToRValue(Address addr,
4965 SourceLocation loc) {
4966 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
4967 switch (getEvaluationKind(type)) {
4969 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4971 return lvalue.asAggregateRValue();
4973 return RValue::get(EmitLoadOfScalar(lvalue, loc));
4975 llvm_unreachable("bad evaluation kind");
4978 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4979 assert(Val->getType()->isFPOrFPVectorTy());
4980 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4983 llvm::MDBuilder MDHelper(getLLVMContext());
4984 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
4986 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
4990 struct LValueOrRValue {
4996 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
4997 const PseudoObjectExpr *E,
4999 AggValueSlot slot) {
5000 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
5002 // Find the result expression, if any.
5003 const Expr *resultExpr = E->getResultExpr();
5004 LValueOrRValue result;
5006 for (PseudoObjectExpr::const_semantics_iterator
5007 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
5008 const Expr *semantic = *i;
5010 // If this semantic expression is an opaque value, bind it
5011 // to the result of its source expression.
5012 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
5013 // Skip unique OVEs.
5014 if (ov->isUnique()) {
5015 assert(ov != resultExpr &&
5016 "A unique OVE cannot be used as the result expression");
5020 // If this is the result expression, we may need to evaluate
5021 // directly into the slot.
5022 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
5024 if (ov == resultExpr && ov->isRValue() && !forLValue &&
5025 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
5026 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
5027 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
5028 AlignmentSource::Decl);
5029 opaqueData = OVMA::bind(CGF, ov, LV);
5030 result.RV = slot.asRValue();
5032 // Otherwise, emit as normal.
5034 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
5036 // If this is the result, also evaluate the result now.
5037 if (ov == resultExpr) {
5039 result.LV = CGF.EmitLValue(ov);
5041 result.RV = CGF.EmitAnyExpr(ov, slot);
5045 opaques.push_back(opaqueData);
5047 // Otherwise, if the expression is the result, evaluate it
5048 // and remember the result.
5049 } else if (semantic == resultExpr) {
5051 result.LV = CGF.EmitLValue(semantic);
5053 result.RV = CGF.EmitAnyExpr(semantic, slot);
5055 // Otherwise, evaluate the expression in an ignored context.
5057 CGF.EmitIgnoredExpr(semantic);
5061 // Unbind all the opaques now.
5062 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
5063 opaques[i].unbind(CGF);
5068 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
5069 AggValueSlot slot) {
5070 return emitPseudoObjectExpr(*this, E, false, slot).RV;
5073 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
5074 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;