1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code to emit Expr nodes as LLVM code.
12 //===----------------------------------------------------------------------===//
16 #include "CGCleanup.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "CGOpenMPRuntime.h"
20 #include "CGRecordLayout.h"
21 #include "CodeGenFunction.h"
22 #include "CodeGenModule.h"
23 #include "ConstantEmitter.h"
24 #include "TargetInfo.h"
25 #include "clang/AST/ASTContext.h"
26 #include "clang/AST/Attr.h"
27 #include "clang/AST/DeclObjC.h"
28 #include "clang/AST/NSAPI.h"
29 #include "clang/Frontend/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::Constant *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.getAddrOfCXXStructor(ReferenceTemporaryDtor,
344 StructorType::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 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
423 // as that will cause the lifetime adjustment to be lost for ARC
424 auto ownership = M->getType().getObjCLifetime();
425 if (ownership != Qualifiers::OCL_None &&
426 ownership != Qualifiers::OCL_ExplicitNone) {
427 Address Object = createReferenceTemporary(*this, M, E);
428 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
429 Object = Address(llvm::ConstantExpr::getBitCast(Var,
430 ConvertTypeForMem(E->getType())
431 ->getPointerTo(Object.getAddressSpace())),
432 Object.getAlignment());
434 // createReferenceTemporary will promote the temporary to a global with a
435 // constant initializer if it can. It can only do this to a value of
436 // ARC-manageable type if the value is global and therefore "immune" to
437 // ref-counting operations. Therefore we have no need to emit either a
438 // dynamic initialization or a cleanup and we can just return the address
440 if (Var->hasInitializer())
441 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
443 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
445 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
446 AlignmentSource::Decl);
448 switch (getEvaluationKind(E->getType())) {
449 default: llvm_unreachable("expected scalar or aggregate expression");
451 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
453 case TEK_Aggregate: {
454 EmitAggExpr(E, AggValueSlot::forAddr(Object,
455 E->getType().getQualifiers(),
456 AggValueSlot::IsDestructed,
457 AggValueSlot::DoesNotNeedGCBarriers,
458 AggValueSlot::IsNotAliased,
459 AggValueSlot::DoesNotOverlap));
464 pushTemporaryCleanup(*this, M, E, Object);
468 SmallVector<const Expr *, 2> CommaLHSs;
469 SmallVector<SubobjectAdjustment, 2> Adjustments;
470 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
472 for (const auto &Ignored : CommaLHSs)
473 EmitIgnoredExpr(Ignored);
475 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
476 if (opaque->getType()->isRecordType()) {
477 assert(Adjustments.empty());
478 return EmitOpaqueValueLValue(opaque);
482 // Create and initialize the reference temporary.
483 Address Alloca = Address::invalid();
484 Address Object = createReferenceTemporary(*this, M, E, &Alloca);
485 if (auto *Var = dyn_cast<llvm::GlobalVariable>(
486 Object.getPointer()->stripPointerCasts())) {
487 Object = Address(llvm::ConstantExpr::getBitCast(
488 cast<llvm::Constant>(Object.getPointer()),
489 ConvertTypeForMem(E->getType())->getPointerTo()),
490 Object.getAlignment());
491 // If the temporary is a global and has a constant initializer or is a
492 // constant temporary that we promoted to a global, we may have already
494 if (!Var->hasInitializer()) {
495 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
496 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
499 switch (M->getStorageDuration()) {
501 case SD_FullExpression:
502 if (auto *Size = EmitLifetimeStart(
503 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
504 Alloca.getPointer())) {
505 if (M->getStorageDuration() == SD_Automatic)
506 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
509 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
516 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
518 pushTemporaryCleanup(*this, M, E, Object);
520 // Perform derived-to-base casts and/or field accesses, to get from the
521 // temporary object we created (and, potentially, for which we extended
522 // the lifetime) to the subobject we're binding the reference to.
523 for (unsigned I = Adjustments.size(); I != 0; --I) {
524 SubobjectAdjustment &Adjustment = Adjustments[I-1];
525 switch (Adjustment.Kind) {
526 case SubobjectAdjustment::DerivedToBaseAdjustment:
528 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
529 Adjustment.DerivedToBase.BasePath->path_begin(),
530 Adjustment.DerivedToBase.BasePath->path_end(),
531 /*NullCheckValue=*/ false, E->getExprLoc());
534 case SubobjectAdjustment::FieldAdjustment: {
535 LValue LV = MakeAddrLValue(Object, E->getType(), AlignmentSource::Decl);
536 LV = EmitLValueForField(LV, Adjustment.Field);
537 assert(LV.isSimple() &&
538 "materialized temporary field is not a simple lvalue");
539 Object = LV.getAddress();
543 case SubobjectAdjustment::MemberPointerAdjustment: {
544 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
545 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
552 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
556 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
557 // Emit the expression as an lvalue.
558 LValue LV = EmitLValue(E);
559 assert(LV.isSimple());
560 llvm::Value *Value = LV.getPointer();
562 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
563 // C++11 [dcl.ref]p5 (as amended by core issue 453):
564 // If a glvalue to which a reference is directly bound designates neither
565 // an existing object or function of an appropriate type nor a region of
566 // storage of suitable size and alignment to contain an object of the
567 // reference's type, the behavior is undefined.
568 QualType Ty = E->getType();
569 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
572 return RValue::get(Value);
576 /// getAccessedFieldNo - Given an encoded value and a result number, return the
577 /// input field number being accessed.
578 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
579 const llvm::Constant *Elts) {
580 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
584 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
585 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
587 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
588 llvm::Value *K47 = Builder.getInt64(47);
589 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
590 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
591 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
592 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
593 return Builder.CreateMul(B1, KMul);
596 bool CodeGenFunction::isNullPointerAllowed(TypeCheckKind TCK) {
597 return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
598 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation;
601 bool CodeGenFunction::isVptrCheckRequired(TypeCheckKind TCK, QualType Ty) {
602 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
603 return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
604 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
605 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
606 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation);
609 bool CodeGenFunction::sanitizePerformTypeCheck() const {
610 return SanOpts.has(SanitizerKind::Null) |
611 SanOpts.has(SanitizerKind::Alignment) |
612 SanOpts.has(SanitizerKind::ObjectSize) |
613 SanOpts.has(SanitizerKind::Vptr);
616 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
617 llvm::Value *Ptr, QualType Ty,
619 SanitizerSet SkippedChecks) {
620 if (!sanitizePerformTypeCheck())
623 // Don't check pointers outside the default address space. The null check
624 // isn't correct, the object-size check isn't supported by LLVM, and we can't
625 // communicate the addresses to the runtime handler for the vptr check.
626 if (Ptr->getType()->getPointerAddressSpace())
629 // Don't check pointers to volatile data. The behavior here is implementation-
631 if (Ty.isVolatileQualified())
634 SanitizerScope SanScope(this);
636 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
637 llvm::BasicBlock *Done = nullptr;
639 // Quickly determine whether we have a pointer to an alloca. It's possible
640 // to skip null checks, and some alignment checks, for these pointers. This
641 // can reduce compile-time significantly.
643 dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
645 llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
646 llvm::Value *IsNonNull = nullptr;
647 bool IsGuaranteedNonNull =
648 SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
649 bool AllowNullPointers = isNullPointerAllowed(TCK);
650 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
651 !IsGuaranteedNonNull) {
652 // The glvalue must not be an empty glvalue.
653 IsNonNull = Builder.CreateIsNotNull(Ptr);
655 // The IR builder can constant-fold the null check if the pointer points to
657 IsGuaranteedNonNull = IsNonNull == True;
659 // Skip the null check if the pointer is known to be non-null.
660 if (!IsGuaranteedNonNull) {
661 if (AllowNullPointers) {
662 // When performing pointer casts, it's OK if the value is null.
663 // Skip the remaining checks in that case.
664 Done = createBasicBlock("null");
665 llvm::BasicBlock *Rest = createBasicBlock("not.null");
666 Builder.CreateCondBr(IsNonNull, Rest, Done);
669 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
674 if (SanOpts.has(SanitizerKind::ObjectSize) &&
675 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
676 !Ty->isIncompleteType()) {
677 uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
679 // The glvalue must refer to a large enough storage region.
680 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
682 // FIXME: Get object address space
683 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
684 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
685 llvm::Value *Min = Builder.getFalse();
686 llvm::Value *NullIsUnknown = Builder.getFalse();
687 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
688 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
689 Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown}),
690 llvm::ConstantInt::get(IntPtrTy, Size));
691 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
694 uint64_t AlignVal = 0;
695 llvm::Value *PtrAsInt = nullptr;
697 if (SanOpts.has(SanitizerKind::Alignment) &&
698 !SkippedChecks.has(SanitizerKind::Alignment)) {
699 AlignVal = Alignment.getQuantity();
700 if (!Ty->isIncompleteType() && !AlignVal)
701 AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
703 // The glvalue must be suitably aligned.
705 (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
706 PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
707 llvm::Value *Align = Builder.CreateAnd(
708 PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
709 llvm::Value *Aligned =
710 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
712 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
716 if (Checks.size() > 0) {
717 // Make sure we're not losing information. Alignment needs to be a power of
719 assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
720 llvm::Constant *StaticData[] = {
721 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
722 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
723 llvm::ConstantInt::get(Int8Ty, TCK)};
724 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
725 PtrAsInt ? PtrAsInt : Ptr);
728 // If possible, check that the vptr indicates that there is a subobject of
729 // type Ty at offset zero within this object.
731 // C++11 [basic.life]p5,6:
732 // [For storage which does not refer to an object within its lifetime]
733 // The program has undefined behavior if:
734 // -- the [pointer or glvalue] is used to access a non-static data member
735 // or call a non-static member function
736 if (SanOpts.has(SanitizerKind::Vptr) &&
737 !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
738 // Ensure that the pointer is non-null before loading it. If there is no
739 // compile-time guarantee, reuse the run-time null check or emit a new one.
740 if (!IsGuaranteedNonNull) {
742 IsNonNull = Builder.CreateIsNotNull(Ptr);
744 Done = createBasicBlock("vptr.null");
745 llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
746 Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
747 EmitBlock(VptrNotNull);
750 // Compute a hash of the mangled name of the type.
752 // FIXME: This is not guaranteed to be deterministic! Move to a
753 // fingerprinting mechanism once LLVM provides one. For the time
754 // being the implementation happens to be deterministic.
755 SmallString<64> MangledName;
756 llvm::raw_svector_ostream Out(MangledName);
757 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
760 // Blacklist based on the mangled type.
761 if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
762 SanitizerKind::Vptr, Out.str())) {
763 llvm::hash_code TypeHash = hash_value(Out.str());
765 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
766 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
767 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
768 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
769 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
770 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
772 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
773 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
775 // Look the hash up in our cache.
776 const int CacheSize = 128;
777 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
778 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
779 "__ubsan_vptr_type_cache");
780 llvm::Value *Slot = Builder.CreateAnd(Hash,
781 llvm::ConstantInt::get(IntPtrTy,
783 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
784 llvm::Value *CacheVal =
785 Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
788 // If the hash isn't in the cache, call a runtime handler to perform the
789 // hard work of checking whether the vptr is for an object of the right
790 // type. This will either fill in the cache and return, or produce a
792 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
793 llvm::Constant *StaticData[] = {
794 EmitCheckSourceLocation(Loc),
795 EmitCheckTypeDescriptor(Ty),
796 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
797 llvm::ConstantInt::get(Int8Ty, TCK)
799 llvm::Value *DynamicData[] = { Ptr, Hash };
800 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
801 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
807 Builder.CreateBr(Done);
812 /// Determine whether this expression refers to a flexible array member in a
813 /// struct. We disable array bounds checks for such members.
814 static bool isFlexibleArrayMemberExpr(const Expr *E) {
815 // For compatibility with existing code, we treat arrays of length 0 or
816 // 1 as flexible array members.
817 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
818 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
819 if (CAT->getSize().ugt(1))
821 } else if (!isa<IncompleteArrayType>(AT))
824 E = E->IgnoreParens();
826 // A flexible array member must be the last member in the class.
827 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
828 // FIXME: If the base type of the member expr is not FD->getParent(),
829 // this should not be treated as a flexible array member access.
830 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
831 RecordDecl::field_iterator FI(
832 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
833 return ++FI == FD->getParent()->field_end();
835 } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
836 return IRE->getDecl()->getNextIvar() == nullptr;
842 llvm::Value *CodeGenFunction::LoadPassedObjectSize(const Expr *E,
844 ASTContext &C = getContext();
845 uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
849 auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
853 auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
857 auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
861 // Don't load the size if it's a lower bound.
862 int POSType = POSAttr->getType();
863 if (POSType != 0 && POSType != 1)
866 // Find the implicit size parameter.
867 auto PassedSizeIt = SizeArguments.find(ParamDecl);
868 if (PassedSizeIt == SizeArguments.end())
871 const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
872 assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
873 Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
874 llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
875 C.getSizeType(), E->getExprLoc());
876 llvm::Value *SizeOfElement =
877 llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
878 return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
881 /// If Base is known to point to the start of an array, return the length of
882 /// that array. Return 0 if the length cannot be determined.
883 static llvm::Value *getArrayIndexingBound(
884 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
885 // For the vector indexing extension, the bound is the number of elements.
886 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
887 IndexedType = Base->getType();
888 return CGF.Builder.getInt32(VT->getNumElements());
891 Base = Base->IgnoreParens();
893 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
894 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
895 !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
896 IndexedType = CE->getSubExpr()->getType();
897 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
898 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
899 return CGF.Builder.getInt(CAT->getSize());
900 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
901 return CGF.getVLASize(VAT).NumElts;
902 // Ignore pass_object_size here. It's not applicable on decayed pointers.
906 QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
907 if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
908 IndexedType = Base->getType();
915 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
916 llvm::Value *Index, QualType IndexType,
918 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
919 "should not be called unless adding bounds checks");
920 SanitizerScope SanScope(this);
922 QualType IndexedType;
923 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
927 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
928 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
929 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
931 llvm::Constant *StaticData[] = {
932 EmitCheckSourceLocation(E->getExprLoc()),
933 EmitCheckTypeDescriptor(IndexedType),
934 EmitCheckTypeDescriptor(IndexType)
936 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
937 : Builder.CreateICmpULE(IndexVal, BoundVal);
938 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
939 SanitizerHandler::OutOfBounds, StaticData, Index);
943 CodeGenFunction::ComplexPairTy CodeGenFunction::
944 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
945 bool isInc, bool isPre) {
946 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
948 llvm::Value *NextVal;
949 if (isa<llvm::IntegerType>(InVal.first->getType())) {
950 uint64_t AmountVal = isInc ? 1 : -1;
951 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
953 // Add the inc/dec to the real part.
954 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
956 QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
957 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
960 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
962 // Add the inc/dec to the real part.
963 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
966 ComplexPairTy IncVal(NextVal, InVal.second);
968 // Store the updated result through the lvalue.
969 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
971 // If this is a postinc, return the value read from memory, otherwise use the
973 return isPre ? IncVal : InVal;
976 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
977 CodeGenFunction *CGF) {
978 // Bind VLAs in the cast type.
979 if (CGF && E->getType()->isVariablyModifiedType())
980 CGF->EmitVariablyModifiedType(E->getType());
982 if (CGDebugInfo *DI = getModuleDebugInfo())
983 DI->EmitExplicitCastType(E->getType());
986 //===----------------------------------------------------------------------===//
987 // LValue Expression Emission
988 //===----------------------------------------------------------------------===//
990 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
991 /// derive a more accurate bound on the alignment of the pointer.
992 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
993 LValueBaseInfo *BaseInfo,
994 TBAAAccessInfo *TBAAInfo) {
995 // We allow this with ObjC object pointers because of fragile ABIs.
996 assert(E->getType()->isPointerType() ||
997 E->getType()->isObjCObjectPointerType());
998 E = E->IgnoreParens();
1001 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1002 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1003 CGM.EmitExplicitCastExprType(ECE, this);
1005 switch (CE->getCastKind()) {
1006 // Non-converting casts (but not C's implicit conversion from void*).
1009 case CK_AddressSpaceConversion:
1010 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1011 if (PtrTy->getPointeeType()->isVoidType())
1014 LValueBaseInfo InnerBaseInfo;
1015 TBAAAccessInfo InnerTBAAInfo;
1016 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1019 if (BaseInfo) *BaseInfo = InnerBaseInfo;
1020 if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1022 if (isa<ExplicitCastExpr>(CE)) {
1023 LValueBaseInfo TargetTypeBaseInfo;
1024 TBAAAccessInfo TargetTypeTBAAInfo;
1025 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
1026 &TargetTypeBaseInfo,
1027 &TargetTypeTBAAInfo);
1029 *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1030 TargetTypeTBAAInfo);
1031 // If the source l-value is opaque, honor the alignment of the
1033 if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1035 BaseInfo->mergeForCast(TargetTypeBaseInfo);
1036 Addr = Address(Addr.getPointer(), Align);
1040 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1041 CE->getCastKind() == CK_BitCast) {
1042 if (auto PT = E->getType()->getAs<PointerType>())
1043 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1045 CodeGenFunction::CFITCK_UnrelatedCast,
1048 return CE->getCastKind() != CK_AddressSpaceConversion
1049 ? Builder.CreateBitCast(Addr, ConvertType(E->getType()))
1050 : Builder.CreateAddrSpaceCast(Addr,
1051 ConvertType(E->getType()));
1055 // Array-to-pointer decay.
1056 case CK_ArrayToPointerDecay:
1057 return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1059 // Derived-to-base conversions.
1060 case CK_UncheckedDerivedToBase:
1061 case CK_DerivedToBase: {
1062 // TODO: Support accesses to members of base classes in TBAA. For now, we
1063 // conservatively pretend that the complete object is of the base class
1066 *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1067 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1068 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1069 return GetAddressOfBaseClass(Addr, Derived,
1070 CE->path_begin(), CE->path_end(),
1071 ShouldNullCheckClassCastValue(CE),
1075 // TODO: Is there any reason to treat base-to-derived conversions
1083 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1084 if (UO->getOpcode() == UO_AddrOf) {
1085 LValue LV = EmitLValue(UO->getSubExpr());
1086 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1087 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1088 return LV.getAddress();
1092 // TODO: conditional operators, comma.
1094 // Otherwise, use the alignment of the type.
1095 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo,
1097 return Address(EmitScalarExpr(E), Align);
1100 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
1101 if (Ty->isVoidType())
1102 return RValue::get(nullptr);
1104 switch (getEvaluationKind(Ty)) {
1107 ConvertType(Ty->castAs<ComplexType>()->getElementType());
1108 llvm::Value *U = llvm::UndefValue::get(EltTy);
1109 return RValue::getComplex(std::make_pair(U, U));
1112 // If this is a use of an undefined aggregate type, the aggregate must have an
1113 // identifiable address. Just because the contents of the value are undefined
1114 // doesn't mean that the address can't be taken and compared.
1115 case TEK_Aggregate: {
1116 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1117 return RValue::getAggregate(DestPtr);
1121 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1123 llvm_unreachable("bad evaluation kind");
1126 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
1128 ErrorUnsupported(E, Name);
1129 return GetUndefRValue(E->getType());
1132 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
1134 ErrorUnsupported(E, Name);
1135 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1136 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1140 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
1141 const Expr *Base = Obj;
1142 while (!isa<CXXThisExpr>(Base)) {
1143 // The result of a dynamic_cast can be null.
1144 if (isa<CXXDynamicCastExpr>(Base))
1147 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1148 Base = CE->getSubExpr();
1149 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1150 Base = PE->getSubExpr();
1151 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1152 if (UO->getOpcode() == UO_Extension)
1153 Base = UO->getSubExpr();
1163 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1165 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1166 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1169 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1170 SanitizerSet SkippedChecks;
1171 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1172 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1174 SkippedChecks.set(SanitizerKind::Alignment, true);
1175 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1176 SkippedChecks.set(SanitizerKind::Null, true);
1178 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1179 E->getType(), LV.getAlignment(), SkippedChecks);
1184 /// EmitLValue - Emit code to compute a designator that specifies the location
1185 /// of the expression.
1187 /// This can return one of two things: a simple address or a bitfield reference.
1188 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1189 /// an LLVM pointer type.
1191 /// If this returns a bitfield reference, nothing about the pointee type of the
1192 /// LLVM value is known: For example, it may not be a pointer to an integer.
1194 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1195 /// this method guarantees that the returned pointer type will point to an LLVM
1196 /// type of the same size of the lvalue's type. If the lvalue has a variable
1197 /// length type, this is not possible.
1199 LValue CodeGenFunction::EmitLValue(const Expr *E) {
1200 ApplyDebugLocation DL(*this, E);
1201 switch (E->getStmtClass()) {
1202 default: return EmitUnsupportedLValue(E, "l-value expression");
1204 case Expr::ObjCPropertyRefExprClass:
1205 llvm_unreachable("cannot emit a property reference directly");
1207 case Expr::ObjCSelectorExprClass:
1208 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1209 case Expr::ObjCIsaExprClass:
1210 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1211 case Expr::BinaryOperatorClass:
1212 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1213 case Expr::CompoundAssignOperatorClass: {
1214 QualType Ty = E->getType();
1215 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1216 Ty = AT->getValueType();
1217 if (!Ty->isAnyComplexType())
1218 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1219 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1221 case Expr::CallExprClass:
1222 case Expr::CXXMemberCallExprClass:
1223 case Expr::CXXOperatorCallExprClass:
1224 case Expr::UserDefinedLiteralClass:
1225 return EmitCallExprLValue(cast<CallExpr>(E));
1226 case Expr::VAArgExprClass:
1227 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1228 case Expr::DeclRefExprClass:
1229 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1230 case Expr::ParenExprClass:
1231 return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1232 case Expr::GenericSelectionExprClass:
1233 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1234 case Expr::PredefinedExprClass:
1235 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1236 case Expr::StringLiteralClass:
1237 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1238 case Expr::ObjCEncodeExprClass:
1239 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1240 case Expr::PseudoObjectExprClass:
1241 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1242 case Expr::InitListExprClass:
1243 return EmitInitListLValue(cast<InitListExpr>(E));
1244 case Expr::CXXTemporaryObjectExprClass:
1245 case Expr::CXXConstructExprClass:
1246 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1247 case Expr::CXXBindTemporaryExprClass:
1248 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1249 case Expr::CXXUuidofExprClass:
1250 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1251 case Expr::LambdaExprClass:
1252 return EmitLambdaLValue(cast<LambdaExpr>(E));
1254 case Expr::ExprWithCleanupsClass: {
1255 const auto *cleanups = cast<ExprWithCleanups>(E);
1256 enterFullExpression(cleanups);
1257 RunCleanupsScope Scope(*this);
1258 LValue LV = EmitLValue(cleanups->getSubExpr());
1259 if (LV.isSimple()) {
1260 // Defend against branches out of gnu statement expressions surrounded by
1262 llvm::Value *V = LV.getPointer();
1263 Scope.ForceCleanup({&V});
1264 return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1265 getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1267 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1268 // bitfield lvalue or some other non-simple lvalue?
1272 case Expr::CXXDefaultArgExprClass:
1273 return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1274 case Expr::CXXDefaultInitExprClass: {
1275 CXXDefaultInitExprScope Scope(*this);
1276 return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1278 case Expr::CXXTypeidExprClass:
1279 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1281 case Expr::ObjCMessageExprClass:
1282 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1283 case Expr::ObjCIvarRefExprClass:
1284 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1285 case Expr::StmtExprClass:
1286 return EmitStmtExprLValue(cast<StmtExpr>(E));
1287 case Expr::UnaryOperatorClass:
1288 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1289 case Expr::ArraySubscriptExprClass:
1290 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1291 case Expr::OMPArraySectionExprClass:
1292 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1293 case Expr::ExtVectorElementExprClass:
1294 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1295 case Expr::MemberExprClass:
1296 return EmitMemberExpr(cast<MemberExpr>(E));
1297 case Expr::CompoundLiteralExprClass:
1298 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1299 case Expr::ConditionalOperatorClass:
1300 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1301 case Expr::BinaryConditionalOperatorClass:
1302 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1303 case Expr::ChooseExprClass:
1304 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1305 case Expr::OpaqueValueExprClass:
1306 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1307 case Expr::SubstNonTypeTemplateParmExprClass:
1308 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1309 case Expr::ImplicitCastExprClass:
1310 case Expr::CStyleCastExprClass:
1311 case Expr::CXXFunctionalCastExprClass:
1312 case Expr::CXXStaticCastExprClass:
1313 case Expr::CXXDynamicCastExprClass:
1314 case Expr::CXXReinterpretCastExprClass:
1315 case Expr::CXXConstCastExprClass:
1316 case Expr::ObjCBridgedCastExprClass:
1317 return EmitCastLValue(cast<CastExpr>(E));
1319 case Expr::MaterializeTemporaryExprClass:
1320 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1322 case Expr::CoawaitExprClass:
1323 return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1324 case Expr::CoyieldExprClass:
1325 return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1329 /// Given an object of the given canonical type, can we safely copy a
1330 /// value out of it based on its initializer?
1331 static bool isConstantEmittableObjectType(QualType type) {
1332 assert(type.isCanonical());
1333 assert(!type->isReferenceType());
1335 // Must be const-qualified but non-volatile.
1336 Qualifiers qs = type.getLocalQualifiers();
1337 if (!qs.hasConst() || qs.hasVolatile()) return false;
1339 // Otherwise, all object types satisfy this except C++ classes with
1340 // mutable subobjects or non-trivial copy/destroy behavior.
1341 if (const auto *RT = dyn_cast<RecordType>(type))
1342 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1343 if (RD->hasMutableFields() || !RD->isTrivial())
1349 /// Can we constant-emit a load of a reference to a variable of the
1350 /// given type? This is different from predicates like
1351 /// Decl::isUsableInConstantExpressions because we do want it to apply
1352 /// in situations that don't necessarily satisfy the language's rules
1353 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1354 /// to do this with const float variables even if those variables
1355 /// aren't marked 'constexpr'.
1356 enum ConstantEmissionKind {
1358 CEK_AsReferenceOnly,
1359 CEK_AsValueOrReference,
1362 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1363 type = type.getCanonicalType();
1364 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1365 if (isConstantEmittableObjectType(ref->getPointeeType()))
1366 return CEK_AsValueOrReference;
1367 return CEK_AsReferenceOnly;
1369 if (isConstantEmittableObjectType(type))
1370 return CEK_AsValueOnly;
1374 /// Try to emit a reference to the given value without producing it as
1375 /// an l-value. This is actually more than an optimization: we can't
1376 /// produce an l-value for variables that we never actually captured
1377 /// in a block or lambda, which means const int variables or constexpr
1378 /// literals or similar.
1379 CodeGenFunction::ConstantEmission
1380 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1381 ValueDecl *value = refExpr->getDecl();
1383 // The value needs to be an enum constant or a constant variable.
1384 ConstantEmissionKind CEK;
1385 if (isa<ParmVarDecl>(value)) {
1387 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1388 CEK = checkVarTypeForConstantEmission(var->getType());
1389 } else if (isa<EnumConstantDecl>(value)) {
1390 CEK = CEK_AsValueOnly;
1394 if (CEK == CEK_None) return ConstantEmission();
1396 Expr::EvalResult result;
1397 bool resultIsReference;
1398 QualType resultType;
1400 // It's best to evaluate all the way as an r-value if that's permitted.
1401 if (CEK != CEK_AsReferenceOnly &&
1402 refExpr->EvaluateAsRValue(result, getContext())) {
1403 resultIsReference = false;
1404 resultType = refExpr->getType();
1406 // Otherwise, try to evaluate as an l-value.
1407 } else if (CEK != CEK_AsValueOnly &&
1408 refExpr->EvaluateAsLValue(result, getContext())) {
1409 resultIsReference = true;
1410 resultType = value->getType();
1414 return ConstantEmission();
1417 // In any case, if the initializer has side-effects, abandon ship.
1418 if (result.HasSideEffects)
1419 return ConstantEmission();
1421 // Emit as a constant.
1422 auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1423 result.Val, resultType);
1425 // Make sure we emit a debug reference to the global variable.
1426 // This should probably fire even for
1427 if (isa<VarDecl>(value)) {
1428 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1429 EmitDeclRefExprDbgValue(refExpr, result.Val);
1431 assert(isa<EnumConstantDecl>(value));
1432 EmitDeclRefExprDbgValue(refExpr, result.Val);
1435 // If we emitted a reference constant, we need to dereference that.
1436 if (resultIsReference)
1437 return ConstantEmission::forReference(C);
1439 return ConstantEmission::forValue(C);
1442 static DeclRefExpr *tryToConvertMemberExprToDeclRefExpr(CodeGenFunction &CGF,
1443 const MemberExpr *ME) {
1444 if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1445 // Try to emit static variable member expressions as DREs.
1446 return DeclRefExpr::Create(
1447 CGF.getContext(), NestedNameSpecifierLoc(), SourceLocation(), VD,
1448 /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1449 ME->getType(), ME->getValueKind());
1454 CodeGenFunction::ConstantEmission
1455 CodeGenFunction::tryEmitAsConstant(const MemberExpr *ME) {
1456 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1457 return tryEmitAsConstant(DRE);
1458 return ConstantEmission();
1461 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1462 SourceLocation Loc) {
1463 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1464 lvalue.getType(), Loc, lvalue.getBaseInfo(),
1465 lvalue.getTBAAInfo(), lvalue.isNontemporal());
1468 static bool hasBooleanRepresentation(QualType Ty) {
1469 if (Ty->isBooleanType())
1472 if (const EnumType *ET = Ty->getAs<EnumType>())
1473 return ET->getDecl()->getIntegerType()->isBooleanType();
1475 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1476 return hasBooleanRepresentation(AT->getValueType());
1481 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1482 llvm::APInt &Min, llvm::APInt &End,
1483 bool StrictEnums, bool IsBool) {
1484 const EnumType *ET = Ty->getAs<EnumType>();
1485 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1486 ET && !ET->getDecl()->isFixed();
1487 if (!IsBool && !IsRegularCPlusPlusEnum)
1491 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1492 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1494 const EnumDecl *ED = ET->getDecl();
1495 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1496 unsigned Bitwidth = LTy->getScalarSizeInBits();
1497 unsigned NumNegativeBits = ED->getNumNegativeBits();
1498 unsigned NumPositiveBits = ED->getNumPositiveBits();
1500 if (NumNegativeBits) {
1501 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1502 assert(NumBits <= Bitwidth);
1503 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1506 assert(NumPositiveBits <= Bitwidth);
1507 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1508 Min = llvm::APInt(Bitwidth, 0);
1514 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1515 llvm::APInt Min, End;
1516 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1517 hasBooleanRepresentation(Ty)))
1520 llvm::MDBuilder MDHelper(getLLVMContext());
1521 return MDHelper.createRange(Min, End);
1524 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1525 SourceLocation Loc) {
1526 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1527 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1528 if (!HasBoolCheck && !HasEnumCheck)
1531 bool IsBool = hasBooleanRepresentation(Ty) ||
1532 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1533 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1534 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1535 if (!NeedsBoolCheck && !NeedsEnumCheck)
1538 // Single-bit booleans don't need to be checked. Special-case this to avoid
1539 // a bit width mismatch when handling bitfield values. This is handled by
1540 // EmitFromMemory for the non-bitfield case.
1542 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1545 llvm::APInt Min, End;
1546 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1549 auto &Ctx = getLLVMContext();
1550 SanitizerScope SanScope(this);
1554 Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1556 llvm::Value *Upper =
1557 Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1558 llvm::Value *Lower =
1559 Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1560 Check = Builder.CreateAnd(Upper, Lower);
1562 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1563 EmitCheckTypeDescriptor(Ty)};
1564 SanitizerMask Kind =
1565 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1566 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1567 StaticArgs, EmitCheckValue(Value));
1571 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1574 LValueBaseInfo BaseInfo,
1575 TBAAAccessInfo TBAAInfo,
1576 bool isNontemporal) {
1577 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1578 // For better performance, handle vector loads differently.
1579 if (Ty->isVectorType()) {
1580 const llvm::Type *EltTy = Addr.getElementType();
1582 const auto *VTy = cast<llvm::VectorType>(EltTy);
1584 // Handle vectors of size 3 like size 4 for better performance.
1585 if (VTy->getNumElements() == 3) {
1587 // Bitcast to vec4 type.
1588 llvm::VectorType *vec4Ty =
1589 llvm::VectorType::get(VTy->getElementType(), 4);
1590 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1592 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1594 // Shuffle vector to get vec3.
1595 V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1596 {0, 1, 2}, "extractVec");
1597 return EmitFromMemory(V, Ty);
1602 // Atomic operations have to be done on integral types.
1603 LValue AtomicLValue =
1604 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1605 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1606 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1609 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1610 if (isNontemporal) {
1611 llvm::MDNode *Node = llvm::MDNode::get(
1612 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1613 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1616 CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1618 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1619 // In order to prevent the optimizer from throwing away the check, don't
1620 // attach range metadata to the load.
1621 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1622 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1623 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1625 return EmitFromMemory(Load, Ty);
1628 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1629 // Bool has a different representation in memory than in registers.
1630 if (hasBooleanRepresentation(Ty)) {
1631 // This should really always be an i1, but sometimes it's already
1632 // an i8, and it's awkward to track those cases down.
1633 if (Value->getType()->isIntegerTy(1))
1634 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1635 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1636 "wrong value rep of bool");
1642 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1643 // Bool has a different representation in memory than in registers.
1644 if (hasBooleanRepresentation(Ty)) {
1645 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1646 "wrong value rep of bool");
1647 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1653 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1654 bool Volatile, QualType Ty,
1655 LValueBaseInfo BaseInfo,
1656 TBAAAccessInfo TBAAInfo,
1657 bool isInit, bool isNontemporal) {
1658 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1659 // Handle vectors differently to get better performance.
1660 if (Ty->isVectorType()) {
1661 llvm::Type *SrcTy = Value->getType();
1662 auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1663 // Handle vec3 special.
1664 if (VecTy && VecTy->getNumElements() == 3) {
1665 // Our source is a vec3, do a shuffle vector to make it a vec4.
1666 llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1667 Builder.getInt32(2),
1668 llvm::UndefValue::get(Builder.getInt32Ty())};
1669 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1670 Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1671 MaskV, "extractVec");
1672 SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1674 if (Addr.getElementType() != SrcTy) {
1675 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1680 Value = EmitToMemory(Value, Ty);
1682 LValue AtomicLValue =
1683 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1684 if (Ty->isAtomicType() ||
1685 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1686 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1690 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1691 if (isNontemporal) {
1692 llvm::MDNode *Node =
1693 llvm::MDNode::get(Store->getContext(),
1694 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1695 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1698 CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1701 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1703 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1704 lvalue.getType(), lvalue.getBaseInfo(),
1705 lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1708 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1709 /// method emits the address of the lvalue, then loads the result as an rvalue,
1710 /// returning the rvalue.
1711 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1712 if (LV.isObjCWeak()) {
1713 // load of a __weak object.
1714 Address AddrWeakObj = LV.getAddress();
1715 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1718 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1719 // In MRC mode, we do a load+autorelease.
1720 if (!getLangOpts().ObjCAutoRefCount) {
1721 return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1724 // In ARC mode, we load retained and then consume the value.
1725 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
1726 Object = EmitObjCConsumeObject(LV.getType(), Object);
1727 return RValue::get(Object);
1730 if (LV.isSimple()) {
1731 assert(!LV.getType()->isFunctionType());
1733 // Everything needs a load.
1734 return RValue::get(EmitLoadOfScalar(LV, Loc));
1737 if (LV.isVectorElt()) {
1738 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1739 LV.isVolatileQualified());
1740 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1744 // If this is a reference to a subset of the elements of a vector, either
1745 // shuffle the input or extract/insert them as appropriate.
1746 if (LV.isExtVectorElt())
1747 return EmitLoadOfExtVectorElementLValue(LV);
1749 // Global Register variables always invoke intrinsics
1750 if (LV.isGlobalReg())
1751 return EmitLoadOfGlobalRegLValue(LV);
1753 assert(LV.isBitField() && "Unknown LValue type!");
1754 return EmitLoadOfBitfieldLValue(LV, Loc);
1757 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
1758 SourceLocation Loc) {
1759 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1761 // Get the output type.
1762 llvm::Type *ResLTy = ConvertType(LV.getType());
1764 Address Ptr = LV.getBitFieldAddress();
1765 llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1767 if (Info.IsSigned) {
1768 assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1769 unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1771 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1772 if (Info.Offset + HighBits)
1773 Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1776 Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1777 if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1778 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1782 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1783 EmitScalarRangeCheck(Val, LV.getType(), Loc);
1784 return RValue::get(Val);
1787 // If this is a reference to a subset of the elements of a vector, create an
1788 // appropriate shufflevector.
1789 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1790 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1791 LV.isVolatileQualified());
1793 const llvm::Constant *Elts = LV.getExtVectorElts();
1795 // If the result of the expression is a non-vector type, we must be extracting
1796 // a single element. Just codegen as an extractelement.
1797 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1799 unsigned InIdx = getAccessedFieldNo(0, Elts);
1800 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1801 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1804 // Always use shuffle vector to try to retain the original program structure
1805 unsigned NumResultElts = ExprVT->getNumElements();
1807 SmallVector<llvm::Constant*, 4> Mask;
1808 for (unsigned i = 0; i != NumResultElts; ++i)
1809 Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1811 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1812 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1814 return RValue::get(Vec);
1817 /// Generates lvalue for partial ext_vector access.
1818 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
1819 Address VectorAddress = LV.getExtVectorAddress();
1820 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1821 QualType EQT = ExprVT->getElementType();
1822 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1824 Address CastToPointerElement =
1825 Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1826 "conv.ptr.element");
1828 const llvm::Constant *Elts = LV.getExtVectorElts();
1829 unsigned ix = getAccessedFieldNo(0, Elts);
1831 Address VectorBasePtrPlusIx =
1832 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1833 getContext().getTypeSizeInChars(EQT),
1836 return VectorBasePtrPlusIx;
1839 /// Load of global gamed gegisters are always calls to intrinsics.
1840 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
1841 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1842 "Bad type for register variable");
1843 llvm::MDNode *RegName = cast<llvm::MDNode>(
1844 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1846 // We accept integer and pointer types only
1847 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1848 llvm::Type *Ty = OrigTy;
1849 if (OrigTy->isPointerTy())
1850 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1851 llvm::Type *Types[] = { Ty };
1853 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1854 llvm::Value *Call = Builder.CreateCall(
1855 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1856 if (OrigTy->isPointerTy())
1857 Call = Builder.CreateIntToPtr(Call, OrigTy);
1858 return RValue::get(Call);
1862 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1863 /// lvalue, where both are guaranteed to the have the same type, and that type
1865 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
1867 if (!Dst.isSimple()) {
1868 if (Dst.isVectorElt()) {
1869 // Read/modify/write the vector, inserting the new element.
1870 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
1871 Dst.isVolatileQualified());
1872 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1873 Dst.getVectorIdx(), "vecins");
1874 Builder.CreateStore(Vec, Dst.getVectorAddress(),
1875 Dst.isVolatileQualified());
1879 // If this is an update of extended vector elements, insert them as
1881 if (Dst.isExtVectorElt())
1882 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
1884 if (Dst.isGlobalReg())
1885 return EmitStoreThroughGlobalRegLValue(Src, Dst);
1887 assert(Dst.isBitField() && "Unknown LValue type");
1888 return EmitStoreThroughBitfieldLValue(Src, Dst);
1891 // There's special magic for assigning into an ARC-qualified l-value.
1892 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1894 case Qualifiers::OCL_None:
1895 llvm_unreachable("present but none");
1897 case Qualifiers::OCL_ExplicitNone:
1901 case Qualifiers::OCL_Strong:
1903 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1906 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1909 case Qualifiers::OCL_Weak:
1911 // Initialize and then skip the primitive store.
1912 EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1914 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1917 case Qualifiers::OCL_Autoreleasing:
1918 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
1919 Src.getScalarVal()));
1920 // fall into the normal path
1925 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1926 // load of a __weak object.
1927 Address LvalueDst = Dst.getAddress();
1928 llvm::Value *src = Src.getScalarVal();
1929 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1933 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1934 // load of a __strong object.
1935 Address LvalueDst = Dst.getAddress();
1936 llvm::Value *src = Src.getScalarVal();
1937 if (Dst.isObjCIvar()) {
1938 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1939 llvm::Type *ResultType = IntPtrTy;
1940 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
1941 llvm::Value *RHS = dst.getPointer();
1942 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1944 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1945 "sub.ptr.lhs.cast");
1946 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
1947 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1949 } else if (Dst.isGlobalObjCRef()) {
1950 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1951 Dst.isThreadLocalRef());
1954 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1958 assert(Src.isScalar() && "Can't emit an agg store with this method");
1959 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
1962 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
1963 llvm::Value **Result) {
1964 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1965 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1966 Address Ptr = Dst.getBitFieldAddress();
1968 // Get the source value, truncated to the width of the bit-field.
1969 llvm::Value *SrcVal = Src.getScalarVal();
1971 // Cast the source to the storage type and shift it into place.
1972 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
1973 /*IsSigned=*/false);
1974 llvm::Value *MaskedVal = SrcVal;
1976 // See if there are other bits in the bitfield's storage we'll need to load
1977 // and mask together with source before storing.
1978 if (Info.StorageSize != Info.Size) {
1979 assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
1981 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
1983 // Mask the source value as needed.
1984 if (!hasBooleanRepresentation(Dst.getType()))
1985 SrcVal = Builder.CreateAnd(SrcVal,
1986 llvm::APInt::getLowBitsSet(Info.StorageSize,
1991 SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
1993 // Mask out the original value.
1994 Val = Builder.CreateAnd(Val,
1995 ~llvm::APInt::getBitsSet(Info.StorageSize,
1997 Info.Offset + Info.Size),
2000 // Or together the unchanged values and the source value.
2001 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2003 assert(Info.Offset == 0);
2006 // Write the new value back out.
2007 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2009 // Return the new value of the bit-field, if requested.
2011 llvm::Value *ResultVal = MaskedVal;
2013 // Sign extend the value if needed.
2014 if (Info.IsSigned) {
2015 assert(Info.Size <= Info.StorageSize);
2016 unsigned HighBits = Info.StorageSize - Info.Size;
2018 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2019 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2023 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2025 *Result = EmitFromMemory(ResultVal, Dst.getType());
2029 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
2031 // This access turns into a read/modify/write of the vector. Load the input
2033 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
2034 Dst.isVolatileQualified());
2035 const llvm::Constant *Elts = Dst.getExtVectorElts();
2037 llvm::Value *SrcVal = Src.getScalarVal();
2039 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2040 unsigned NumSrcElts = VTy->getNumElements();
2041 unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2042 if (NumDstElts == NumSrcElts) {
2043 // Use shuffle vector is the src and destination are the same number of
2044 // elements and restore the vector mask since it is on the side it will be
2046 SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2047 for (unsigned i = 0; i != NumSrcElts; ++i)
2048 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2050 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2051 Vec = Builder.CreateShuffleVector(SrcVal,
2052 llvm::UndefValue::get(Vec->getType()),
2054 } else if (NumDstElts > NumSrcElts) {
2055 // Extended the source vector to the same length and then shuffle it
2056 // into the destination.
2057 // FIXME: since we're shuffling with undef, can we just use the indices
2058 // into that? This could be simpler.
2059 SmallVector<llvm::Constant*, 4> ExtMask;
2060 for (unsigned i = 0; i != NumSrcElts; ++i)
2061 ExtMask.push_back(Builder.getInt32(i));
2062 ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2063 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2064 llvm::Value *ExtSrcVal =
2065 Builder.CreateShuffleVector(SrcVal,
2066 llvm::UndefValue::get(SrcVal->getType()),
2069 SmallVector<llvm::Constant*, 4> Mask;
2070 for (unsigned i = 0; i != NumDstElts; ++i)
2071 Mask.push_back(Builder.getInt32(i));
2073 // When the vector size is odd and .odd or .hi is used, the last element
2074 // of the Elts constant array will be one past the size of the vector.
2075 // Ignore the last element here, if it is greater than the mask size.
2076 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2079 // modify when what gets shuffled in
2080 for (unsigned i = 0; i != NumSrcElts; ++i)
2081 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2082 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2083 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2085 // We should never shorten the vector
2086 llvm_unreachable("unexpected shorten vector length");
2089 // If the Src is a scalar (not a vector) it must be updating one element.
2090 unsigned InIdx = getAccessedFieldNo(0, Elts);
2091 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2092 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2095 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
2096 Dst.isVolatileQualified());
2099 /// Store of global named registers are always calls to intrinsics.
2100 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
2101 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2102 "Bad type for register variable");
2103 llvm::MDNode *RegName = cast<llvm::MDNode>(
2104 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2105 assert(RegName && "Register LValue is not metadata");
2107 // We accept integer and pointer types only
2108 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2109 llvm::Type *Ty = OrigTy;
2110 if (OrigTy->isPointerTy())
2111 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2112 llvm::Type *Types[] = { Ty };
2114 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2115 llvm::Value *Value = Src.getScalarVal();
2116 if (OrigTy->isPointerTy())
2117 Value = Builder.CreatePtrToInt(Value, Ty);
2119 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2122 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2123 // generating write-barries API. It is currently a global, ivar,
2125 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2127 bool IsMemberAccess=false) {
2128 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2131 if (isa<ObjCIvarRefExpr>(E)) {
2132 QualType ExpTy = E->getType();
2133 if (IsMemberAccess && ExpTy->isPointerType()) {
2134 // If ivar is a structure pointer, assigning to field of
2135 // this struct follows gcc's behavior and makes it a non-ivar
2136 // writer-barrier conservatively.
2137 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2138 if (ExpTy->isRecordType()) {
2139 LV.setObjCIvar(false);
2143 LV.setObjCIvar(true);
2144 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2145 LV.setBaseIvarExp(Exp->getBase());
2146 LV.setObjCArray(E->getType()->isArrayType());
2150 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2151 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2152 if (VD->hasGlobalStorage()) {
2153 LV.setGlobalObjCRef(true);
2154 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2157 LV.setObjCArray(E->getType()->isArrayType());
2161 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2162 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2166 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2167 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2168 if (LV.isObjCIvar()) {
2169 // If cast is to a structure pointer, follow gcc's behavior and make it
2170 // a non-ivar write-barrier.
2171 QualType ExpTy = E->getType();
2172 if (ExpTy->isPointerType())
2173 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2174 if (ExpTy->isRecordType())
2175 LV.setObjCIvar(false);
2180 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2181 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2185 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2186 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2190 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2191 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2195 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2196 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2200 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2201 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2202 if (LV.isObjCIvar() && !LV.isObjCArray())
2203 // Using array syntax to assigning to what an ivar points to is not
2204 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2205 LV.setObjCIvar(false);
2206 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2207 // Using array syntax to assigning to what global points to is not
2208 // same as assigning to the global itself. {id *G;} G[i] = 0;
2209 LV.setGlobalObjCRef(false);
2213 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2214 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2215 // We don't know if member is an 'ivar', but this flag is looked at
2216 // only in the context of LV.isObjCIvar().
2217 LV.setObjCArray(E->getType()->isArrayType());
2222 static llvm::Value *
2223 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
2224 llvm::Value *V, llvm::Type *IRType,
2225 StringRef Name = StringRef()) {
2226 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2227 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2230 static LValue EmitThreadPrivateVarDeclLValue(
2231 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2232 llvm::Type *RealVarTy, SourceLocation Loc) {
2233 Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2234 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2235 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2238 static Address emitDeclTargetLinkVarDeclLValue(CodeGenFunction &CGF,
2239 const VarDecl *VD, QualType T) {
2240 for (const auto *D : VD->redecls()) {
2241 if (!VD->hasAttrs())
2243 if (const auto *Attr = D->getAttr<OMPDeclareTargetDeclAttr>())
2244 if (Attr->getMapType() == OMPDeclareTargetDeclAttr::MT_Link) {
2245 QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2247 CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetLink(VD);
2248 return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2251 return Address::invalid();
2255 CodeGenFunction::EmitLoadOfReference(LValue RefLVal,
2256 LValueBaseInfo *PointeeBaseInfo,
2257 TBAAAccessInfo *PointeeTBAAInfo) {
2258 llvm::LoadInst *Load = Builder.CreateLoad(RefLVal.getAddress(),
2259 RefLVal.isVolatile());
2260 CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2262 CharUnits Align = getNaturalTypeAlignment(RefLVal.getType()->getPointeeType(),
2263 PointeeBaseInfo, PointeeTBAAInfo,
2264 /* forPointeeType= */ true);
2265 return Address(Load, Align);
2268 LValue CodeGenFunction::EmitLoadOfReferenceLValue(LValue RefLVal) {
2269 LValueBaseInfo PointeeBaseInfo;
2270 TBAAAccessInfo PointeeTBAAInfo;
2271 Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2273 return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2274 PointeeBaseInfo, PointeeTBAAInfo);
2277 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2278 const PointerType *PtrTy,
2279 LValueBaseInfo *BaseInfo,
2280 TBAAAccessInfo *TBAAInfo) {
2281 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2282 return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2284 /*forPointeeType=*/true));
2287 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2288 const PointerType *PtrTy) {
2289 LValueBaseInfo BaseInfo;
2290 TBAAAccessInfo TBAAInfo;
2291 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2292 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2295 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2296 const Expr *E, const VarDecl *VD) {
2297 QualType T = E->getType();
2299 // If it's thread_local, emit a call to its wrapper function instead.
2300 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2301 CGF.CGM.getCXXABI().usesThreadWrapperFunction())
2302 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2303 // Check if the variable is marked as declare target with link clause in
2305 if (CGF.getLangOpts().OpenMPIsDevice) {
2306 Address Addr = emitDeclTargetLinkVarDeclLValue(CGF, VD, T);
2308 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2311 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2312 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2313 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2314 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2315 Address Addr(V, Alignment);
2316 // Emit reference to the private copy of the variable if it is an OpenMP
2317 // threadprivate variable.
2318 if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2319 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2320 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2323 LValue LV = VD->getType()->isReferenceType() ?
2324 CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2325 AlignmentSource::Decl) :
2326 CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2327 setObjCGCLValueClass(CGF.getContext(), E, LV);
2331 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2332 const FunctionDecl *FD) {
2333 if (FD->hasAttr<WeakRefAttr>()) {
2334 ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2335 return aliasee.getPointer();
2338 llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2339 if (!FD->hasPrototype()) {
2340 if (const FunctionProtoType *Proto =
2341 FD->getType()->getAs<FunctionProtoType>()) {
2342 // Ugly case: for a K&R-style definition, the type of the definition
2343 // isn't the same as the type of a use. Correct for this with a
2345 QualType NoProtoType =
2346 CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2347 NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2348 V = llvm::ConstantExpr::getBitCast(V,
2349 CGM.getTypes().ConvertType(NoProtoType));
2355 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
2356 const Expr *E, const FunctionDecl *FD) {
2357 llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2358 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2359 return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2360 AlignmentSource::Decl);
2363 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2364 llvm::Value *ThisValue) {
2365 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2366 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2367 return CGF.EmitLValueForField(LV, FD);
2370 /// Named Registers are named metadata pointing to the register name
2371 /// which will be read from/written to as an argument to the intrinsic
2372 /// @llvm.read/write_register.
2373 /// So far, only the name is being passed down, but other options such as
2374 /// register type, allocation type or even optimization options could be
2375 /// passed down via the metadata node.
2376 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2377 SmallString<64> Name("llvm.named.register.");
2378 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2379 assert(Asm->getLabel().size() < 64-Name.size() &&
2380 "Register name too big");
2381 Name.append(Asm->getLabel());
2382 llvm::NamedMDNode *M =
2383 CGM.getModule().getOrInsertNamedMetadata(Name);
2384 if (M->getNumOperands() == 0) {
2385 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2387 llvm::Metadata *Ops[] = {Str};
2388 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2391 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2394 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2395 return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2398 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2399 const NamedDecl *ND = E->getDecl();
2400 QualType T = E->getType();
2402 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2403 // Global Named registers access via intrinsics only
2404 if (VD->getStorageClass() == SC_Register &&
2405 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2406 return EmitGlobalNamedRegister(VD, CGM);
2408 // A DeclRefExpr for a reference initialized by a constant expression can
2409 // appear without being odr-used. Directly emit the constant initializer.
2410 const Expr *Init = VD->getAnyInitializer(VD);
2411 const auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl);
2412 if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2413 VD->isUsableInConstantExpressions(getContext()) &&
2414 VD->checkInitIsICE() &&
2415 // Do not emit if it is private OpenMP variable.
2416 !(E->refersToEnclosingVariableOrCapture() &&
2417 ((CapturedStmtInfo &&
2418 (LocalDeclMap.count(VD->getCanonicalDecl()) ||
2419 CapturedStmtInfo->lookup(VD->getCanonicalDecl()))) ||
2420 LambdaCaptureFields.lookup(VD->getCanonicalDecl()) ||
2421 (BD && BD->capturesVariable(VD))))) {
2422 llvm::Constant *Val =
2423 ConstantEmitter(*this).emitAbstract(E->getLocation(),
2424 *VD->evaluateValue(),
2426 assert(Val && "failed to emit reference constant expression");
2427 // FIXME: Eventually we will want to emit vector element references.
2429 // Should we be using the alignment of the constant pointer we emitted?
2430 CharUnits Alignment = getNaturalTypeAlignment(E->getType(),
2431 /* BaseInfo= */ nullptr,
2432 /* TBAAInfo= */ nullptr,
2433 /* forPointeeType= */ true);
2434 return MakeAddrLValue(Address(Val, Alignment), T, AlignmentSource::Decl);
2437 // Check for captured variables.
2438 if (E->refersToEnclosingVariableOrCapture()) {
2439 VD = VD->getCanonicalDecl();
2440 if (auto *FD = LambdaCaptureFields.lookup(VD))
2441 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2442 else if (CapturedStmtInfo) {
2443 auto I = LocalDeclMap.find(VD);
2444 if (I != LocalDeclMap.end()) {
2445 if (VD->getType()->isReferenceType())
2446 return EmitLoadOfReferenceLValue(I->second, VD->getType(),
2447 AlignmentSource::Decl);
2448 return MakeAddrLValue(I->second, T);
2451 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2452 CapturedStmtInfo->getContextValue());
2453 return MakeAddrLValue(
2454 Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2455 CapLVal.getType(), LValueBaseInfo(AlignmentSource::Decl),
2456 CapLVal.getTBAAInfo());
2459 assert(isa<BlockDecl>(CurCodeDecl));
2460 Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
2461 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2465 // FIXME: We should be able to assert this for FunctionDecls as well!
2466 // FIXME: We should be able to assert this for all DeclRefExprs, not just
2467 // those with a valid source location.
2468 assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2469 !E->getLocation().isValid()) &&
2470 "Should not use decl without marking it used!");
2472 if (ND->hasAttr<WeakRefAttr>()) {
2473 const auto *VD = cast<ValueDecl>(ND);
2474 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2475 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2478 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2479 // Check if this is a global variable.
2480 if (VD->hasLinkage() || VD->isStaticDataMember())
2481 return EmitGlobalVarDeclLValue(*this, E, VD);
2483 Address addr = Address::invalid();
2485 // The variable should generally be present in the local decl map.
2486 auto iter = LocalDeclMap.find(VD);
2487 if (iter != LocalDeclMap.end()) {
2488 addr = iter->second;
2490 // Otherwise, it might be static local we haven't emitted yet for
2491 // some reason; most likely, because it's in an outer function.
2492 } else if (VD->isStaticLocal()) {
2493 addr = Address(CGM.getOrCreateStaticVarDecl(
2494 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2495 getContext().getDeclAlign(VD));
2497 // No other cases for now.
2499 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2503 // Check for OpenMP threadprivate variables.
2504 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2505 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2506 return EmitThreadPrivateVarDeclLValue(
2507 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2511 // Drill into block byref variables.
2512 bool isBlockByref = VD->hasAttr<BlocksAttr>();
2514 addr = emitBlockByrefAddress(addr, VD);
2517 // Drill into reference types.
2518 LValue LV = VD->getType()->isReferenceType() ?
2519 EmitLoadOfReferenceLValue(addr, VD->getType(), AlignmentSource::Decl) :
2520 MakeAddrLValue(addr, T, AlignmentSource::Decl);
2522 bool isLocalStorage = VD->hasLocalStorage();
2524 bool NonGCable = isLocalStorage &&
2525 !VD->getType()->isReferenceType() &&
2528 LV.getQuals().removeObjCGCAttr();
2532 bool isImpreciseLifetime =
2533 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2534 if (isImpreciseLifetime)
2535 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2536 setObjCGCLValueClass(getContext(), E, LV);
2540 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2541 return EmitFunctionDeclLValue(*this, E, FD);
2543 // FIXME: While we're emitting a binding from an enclosing scope, all other
2544 // DeclRefExprs we see should be implicitly treated as if they also refer to
2545 // an enclosing scope.
2546 if (const auto *BD = dyn_cast<BindingDecl>(ND))
2547 return EmitLValue(BD->getBinding());
2549 llvm_unreachable("Unhandled DeclRefExpr");
2552 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2553 // __extension__ doesn't affect lvalue-ness.
2554 if (E->getOpcode() == UO_Extension)
2555 return EmitLValue(E->getSubExpr());
2557 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2558 switch (E->getOpcode()) {
2559 default: llvm_unreachable("Unknown unary operator lvalue!");
2561 QualType T = E->getSubExpr()->getType()->getPointeeType();
2562 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2564 LValueBaseInfo BaseInfo;
2565 TBAAAccessInfo TBAAInfo;
2566 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2568 LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2569 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2571 // We should not generate __weak write barrier on indirect reference
2572 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2573 // But, we continue to generate __strong write barrier on indirect write
2574 // into a pointer to object.
2575 if (getLangOpts().ObjC1 &&
2576 getLangOpts().getGC() != LangOptions::NonGC &&
2578 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2583 LValue LV = EmitLValue(E->getSubExpr());
2584 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2586 // __real is valid on scalars. This is a faster way of testing that.
2587 // __imag can only produce an rvalue on scalars.
2588 if (E->getOpcode() == UO_Real &&
2589 !LV.getAddress().getElementType()->isStructTy()) {
2590 assert(E->getSubExpr()->getType()->isArithmeticType());
2594 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2597 (E->getOpcode() == UO_Real
2598 ? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
2599 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
2600 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2601 CGM.getTBAAInfoForSubobject(LV, T));
2602 ElemLV.getQuals().addQualifiers(LV.getQuals());
2607 LValue LV = EmitLValue(E->getSubExpr());
2608 bool isInc = E->getOpcode() == UO_PreInc;
2610 if (E->getType()->isAnyComplexType())
2611 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2613 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2619 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2620 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2621 E->getType(), AlignmentSource::Decl);
2624 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2625 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2626 E->getType(), AlignmentSource::Decl);
2629 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2630 auto SL = E->getFunctionName();
2631 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2632 StringRef FnName = CurFn->getName();
2633 if (FnName.startswith("\01"))
2634 FnName = FnName.substr(1);
2635 StringRef NameItems[] = {
2636 PredefinedExpr::getIdentTypeName(E->getIdentType()), FnName};
2637 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2638 if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2639 std::string Name = SL->getString();
2640 if (!Name.empty()) {
2641 unsigned Discriminator =
2642 CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2644 Name += "_" + Twine(Discriminator + 1).str();
2645 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2646 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2648 auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2649 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2652 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2653 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2656 /// Emit a type description suitable for use by a runtime sanitizer library. The
2657 /// format of a type descriptor is
2660 /// { i16 TypeKind, i16 TypeInfo }
2663 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2664 /// integer, 1 for a floating point value, and -1 for anything else.
2665 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2666 // Only emit each type's descriptor once.
2667 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2670 uint16_t TypeKind = -1;
2671 uint16_t TypeInfo = 0;
2673 if (T->isIntegerType()) {
2675 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2676 (T->isSignedIntegerType() ? 1 : 0);
2677 } else if (T->isFloatingType()) {
2679 TypeInfo = getContext().getTypeSize(T);
2682 // Format the type name as if for a diagnostic, including quotes and
2683 // optionally an 'aka'.
2684 SmallString<32> Buffer;
2685 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
2686 (intptr_t)T.getAsOpaquePtr(),
2687 StringRef(), StringRef(), None, Buffer,
2690 llvm::Constant *Components[] = {
2691 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2692 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2694 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2696 auto *GV = new llvm::GlobalVariable(
2697 CGM.getModule(), Descriptor->getType(),
2698 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2699 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2700 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
2702 // Remember the descriptor for this type.
2703 CGM.setTypeDescriptorInMap(T, GV);
2708 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
2709 llvm::Type *TargetTy = IntPtrTy;
2711 if (V->getType() == TargetTy)
2714 // Floating-point types which fit into intptr_t are bitcast to integers
2715 // and then passed directly (after zero-extension, if necessary).
2716 if (V->getType()->isFloatingPointTy()) {
2717 unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2718 if (Bits <= TargetTy->getIntegerBitWidth())
2719 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2723 // Integers which fit in intptr_t are zero-extended and passed directly.
2724 if (V->getType()->isIntegerTy() &&
2725 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2726 return Builder.CreateZExt(V, TargetTy);
2728 // Pointers are passed directly, everything else is passed by address.
2729 if (!V->getType()->isPointerTy()) {
2730 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2731 Builder.CreateStore(V, Ptr);
2732 V = Ptr.getPointer();
2734 return Builder.CreatePtrToInt(V, TargetTy);
2737 /// Emit a representation of a SourceLocation for passing to a handler
2738 /// in a sanitizer runtime library. The format for this data is:
2740 /// struct SourceLocation {
2741 /// const char *Filename;
2742 /// int32_t Line, Column;
2745 /// For an invalid SourceLocation, the Filename pointer is null.
2746 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
2747 llvm::Constant *Filename;
2750 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
2751 if (PLoc.isValid()) {
2752 StringRef FilenameString = PLoc.getFilename();
2754 int PathComponentsToStrip =
2755 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2756 if (PathComponentsToStrip < 0) {
2757 assert(PathComponentsToStrip != INT_MIN);
2758 int PathComponentsToKeep = -PathComponentsToStrip;
2759 auto I = llvm::sys::path::rbegin(FilenameString);
2760 auto E = llvm::sys::path::rend(FilenameString);
2761 while (I != E && --PathComponentsToKeep)
2764 FilenameString = FilenameString.substr(I - E);
2765 } else if (PathComponentsToStrip > 0) {
2766 auto I = llvm::sys::path::begin(FilenameString);
2767 auto E = llvm::sys::path::end(FilenameString);
2768 while (I != E && PathComponentsToStrip--)
2773 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2775 FilenameString = llvm::sys::path::filename(FilenameString);
2778 auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2779 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
2780 cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2781 Filename = FilenameGV.getPointer();
2782 Line = PLoc.getLine();
2783 Column = PLoc.getColumn();
2785 Filename = llvm::Constant::getNullValue(Int8PtrTy);
2789 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2790 Builder.getInt32(Column)};
2792 return llvm::ConstantStruct::getAnon(Data);
2796 /// Specify under what conditions this check can be recovered
2797 enum class CheckRecoverableKind {
2798 /// Always terminate program execution if this check fails.
2800 /// Check supports recovering, runtime has both fatal (noreturn) and
2801 /// non-fatal handlers for this check.
2803 /// Runtime conditionally aborts, always need to support recovery.
2808 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
2809 assert(llvm::countPopulation(Kind) == 1);
2811 case SanitizerKind::Vptr:
2812 return CheckRecoverableKind::AlwaysRecoverable;
2813 case SanitizerKind::Return:
2814 case SanitizerKind::Unreachable:
2815 return CheckRecoverableKind::Unrecoverable;
2817 return CheckRecoverableKind::Recoverable;
2822 struct SanitizerHandlerInfo {
2823 char const *const Name;
2828 const SanitizerHandlerInfo SanitizerHandlers[] = {
2829 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2830 LIST_SANITIZER_CHECKS
2831 #undef SANITIZER_CHECK
2834 static void emitCheckHandlerCall(CodeGenFunction &CGF,
2835 llvm::FunctionType *FnType,
2836 ArrayRef<llvm::Value *> FnArgs,
2837 SanitizerHandler CheckHandler,
2838 CheckRecoverableKind RecoverKind, bool IsFatal,
2839 llvm::BasicBlock *ContBB) {
2840 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2841 bool NeedsAbortSuffix =
2842 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2843 bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2844 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2845 const StringRef CheckName = CheckInfo.Name;
2846 std::string FnName = "__ubsan_handle_" + CheckName.str();
2847 if (CheckInfo.Version && !MinimalRuntime)
2848 FnName += "_v" + llvm::utostr(CheckInfo.Version);
2850 FnName += "_minimal";
2851 if (NeedsAbortSuffix)
2854 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2856 llvm::AttrBuilder B;
2858 B.addAttribute(llvm::Attribute::NoReturn)
2859 .addAttribute(llvm::Attribute::NoUnwind);
2861 B.addAttribute(llvm::Attribute::UWTable);
2863 llvm::Value *Fn = CGF.CGM.CreateRuntimeFunction(
2865 llvm::AttributeList::get(CGF.getLLVMContext(),
2866 llvm::AttributeList::FunctionIndex, B),
2868 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2870 HandlerCall->setDoesNotReturn();
2871 CGF.Builder.CreateUnreachable();
2873 CGF.Builder.CreateBr(ContBB);
2877 void CodeGenFunction::EmitCheck(
2878 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2879 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
2880 ArrayRef<llvm::Value *> DynamicArgs) {
2881 assert(IsSanitizerScope);
2882 assert(Checked.size() > 0);
2883 assert(CheckHandler >= 0 &&
2884 size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
2885 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
2887 llvm::Value *FatalCond = nullptr;
2888 llvm::Value *RecoverableCond = nullptr;
2889 llvm::Value *TrapCond = nullptr;
2890 for (int i = 0, n = Checked.size(); i < n; ++i) {
2891 llvm::Value *Check = Checked[i].first;
2892 // -fsanitize-trap= overrides -fsanitize-recover=.
2893 llvm::Value *&Cond =
2894 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2896 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2899 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2903 EmitTrapCheck(TrapCond);
2904 if (!FatalCond && !RecoverableCond)
2907 llvm::Value *JointCond;
2908 if (FatalCond && RecoverableCond)
2909 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2911 JointCond = FatalCond ? FatalCond : RecoverableCond;
2914 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2915 assert(SanOpts.has(Checked[0].second));
2917 for (int i = 1, n = Checked.size(); i < n; ++i) {
2918 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2919 "All recoverable kinds in a single check must be same!");
2920 assert(SanOpts.has(Checked[i].second));
2924 llvm::BasicBlock *Cont = createBasicBlock("cont");
2925 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2926 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2927 // Give hint that we very much don't expect to execute the handler
2928 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2929 llvm::MDBuilder MDHelper(getLLVMContext());
2930 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2931 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2932 EmitBlock(Handlers);
2934 // Handler functions take an i8* pointing to the (handler-specific) static
2935 // information block, followed by a sequence of intptr_t arguments
2936 // representing operand values.
2937 SmallVector<llvm::Value *, 4> Args;
2938 SmallVector<llvm::Type *, 4> ArgTypes;
2939 if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
2940 Args.reserve(DynamicArgs.size() + 1);
2941 ArgTypes.reserve(DynamicArgs.size() + 1);
2943 // Emit handler arguments and create handler function type.
2944 if (!StaticArgs.empty()) {
2945 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2947 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2948 llvm::GlobalVariable::PrivateLinkage, Info);
2949 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2950 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2951 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
2952 ArgTypes.push_back(Int8PtrTy);
2955 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
2956 Args.push_back(EmitCheckValue(DynamicArgs[i]));
2957 ArgTypes.push_back(IntPtrTy);
2961 llvm::FunctionType *FnType =
2962 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
2964 if (!FatalCond || !RecoverableCond) {
2965 // Simple case: we need to generate a single handler call, either
2966 // fatal, or non-fatal.
2967 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
2968 (FatalCond != nullptr), Cont);
2970 // Emit two handler calls: first one for set of unrecoverable checks,
2971 // another one for recoverable.
2972 llvm::BasicBlock *NonFatalHandlerBB =
2973 createBasicBlock("non_fatal." + CheckName);
2974 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
2975 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
2976 EmitBlock(FatalHandlerBB);
2977 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
2979 EmitBlock(NonFatalHandlerBB);
2980 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
2987 void CodeGenFunction::EmitCfiSlowPathCheck(
2988 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
2989 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
2990 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
2992 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
2993 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
2995 llvm::MDBuilder MDHelper(getLLVMContext());
2996 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2997 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3001 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3003 llvm::CallInst *CheckCall;
3004 llvm::Constant *SlowPathFn;
3006 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3008 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3009 llvm::GlobalVariable::PrivateLinkage, Info);
3010 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3011 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3013 SlowPathFn = CGM.getModule().getOrInsertFunction(
3014 "__cfi_slowpath_diag",
3015 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3017 CheckCall = Builder.CreateCall(
3018 SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3020 SlowPathFn = CGM.getModule().getOrInsertFunction(
3022 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3023 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3026 CGM.setDSOLocal(cast<llvm::GlobalValue>(SlowPathFn->stripPointerCasts()));
3027 CheckCall->setDoesNotThrow();
3032 // Emit a stub for __cfi_check function so that the linker knows about this
3033 // symbol in LTO mode.
3034 void CodeGenFunction::EmitCfiCheckStub() {
3035 llvm::Module *M = &CGM.getModule();
3036 auto &Ctx = M->getContext();
3037 llvm::Function *F = llvm::Function::Create(
3038 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3039 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3041 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3042 // FIXME: consider emitting an intrinsic call like
3043 // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3044 // which can be lowered in CrossDSOCFI pass to the actual contents of
3045 // __cfi_check. This would allow inlining of __cfi_check calls.
3046 llvm::CallInst::Create(
3047 llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3048 llvm::ReturnInst::Create(Ctx, nullptr, BB);
3051 // This function is basically a switch over the CFI failure kind, which is
3052 // extracted from CFICheckFailData (1st function argument). Each case is either
3053 // llvm.trap or a call to one of the two runtime handlers, based on
3054 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3055 // failure kind) traps, but this should really never happen. CFICheckFailData
3056 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3057 // check kind; in this case __cfi_check_fail traps as well.
3058 void CodeGenFunction::EmitCfiCheckFail() {
3059 SanitizerScope SanScope(this);
3060 FunctionArgList Args;
3061 ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy,
3062 ImplicitParamDecl::Other);
3063 ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy,
3064 ImplicitParamDecl::Other);
3065 Args.push_back(&ArgData);
3066 Args.push_back(&ArgAddr);
3068 const CGFunctionInfo &FI =
3069 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
3071 llvm::Function *F = llvm::Function::Create(
3072 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3073 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3074 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3076 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3079 // This function should not be affected by blacklist. This function does
3080 // not have a source location, but "src:*" would still apply. Revert any
3081 // changes to SanOpts made in StartFunction.
3082 SanOpts = CGM.getLangOpts().Sanitize;
3085 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3086 CGM.getContext().VoidPtrTy, ArgData.getLocation());
3088 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3089 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3091 // Data == nullptr means the calling module has trap behaviour for this check.
3092 llvm::Value *DataIsNotNullPtr =
3093 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3094 EmitTrapCheck(DataIsNotNullPtr);
3096 llvm::StructType *SourceLocationTy =
3097 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3098 llvm::StructType *CfiCheckFailDataTy =
3099 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3101 llvm::Value *V = Builder.CreateConstGEP2_32(
3103 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3105 Address CheckKindAddr(V, getIntAlign());
3106 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3108 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3109 CGM.getLLVMContext(),
3110 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3111 llvm::Value *ValidVtable = Builder.CreateZExt(
3112 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3113 {Addr, AllVtables}),
3116 const std::pair<int, SanitizerMask> CheckKinds[] = {
3117 {CFITCK_VCall, SanitizerKind::CFIVCall},
3118 {CFITCK_NVCall, SanitizerKind::CFINVCall},
3119 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3120 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3121 {CFITCK_ICall, SanitizerKind::CFIICall}};
3123 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
3124 for (auto CheckKindMaskPair : CheckKinds) {
3125 int Kind = CheckKindMaskPair.first;
3126 SanitizerMask Mask = CheckKindMaskPair.second;
3128 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3129 if (CGM.getLangOpts().Sanitize.has(Mask))
3130 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3131 {Data, Addr, ValidVtable});
3133 EmitTrapCheck(Cond);
3137 // The only reference to this function will be created during LTO link.
3138 // Make sure it survives until then.
3139 CGM.addUsedGlobal(F);
3142 void CodeGenFunction::EmitUnreachable(SourceLocation Loc) {
3143 if (SanOpts.has(SanitizerKind::Unreachable)) {
3144 SanitizerScope SanScope(this);
3145 EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3146 SanitizerKind::Unreachable),
3147 SanitizerHandler::BuiltinUnreachable,
3148 EmitCheckSourceLocation(Loc), None);
3150 Builder.CreateUnreachable();
3153 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
3154 llvm::BasicBlock *Cont = createBasicBlock("cont");
3156 // If we're optimizing, collapse all calls to trap down to just one per
3157 // function to save on code size.
3158 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3159 TrapBB = createBasicBlock("trap");
3160 Builder.CreateCondBr(Checked, Cont, TrapBB);
3162 llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3163 TrapCall->setDoesNotReturn();
3164 TrapCall->setDoesNotThrow();
3165 Builder.CreateUnreachable();
3167 Builder.CreateCondBr(Checked, Cont, TrapBB);
3173 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
3174 llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3176 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3177 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3178 CGM.getCodeGenOpts().TrapFuncName);
3179 TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3185 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
3186 LValueBaseInfo *BaseInfo,
3187 TBAAAccessInfo *TBAAInfo) {
3188 assert(E->getType()->isArrayType() &&
3189 "Array to pointer decay must have array source type!");
3191 // Expressions of array type can't be bitfields or vector elements.
3192 LValue LV = EmitLValue(E);
3193 Address Addr = LV.getAddress();
3195 // If the array type was an incomplete type, we need to make sure
3196 // the decay ends up being the right type.
3197 llvm::Type *NewTy = ConvertType(E->getType());
3198 Addr = Builder.CreateElementBitCast(Addr, NewTy);
3200 // Note that VLA pointers are always decayed, so we don't need to do
3202 if (!E->getType()->isVariableArrayType()) {
3203 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3204 "Expected pointer to array");
3205 Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
3208 // The result of this decay conversion points to an array element within the
3209 // base lvalue. However, since TBAA currently does not support representing
3210 // accesses to elements of member arrays, we conservatively represent accesses
3211 // to the pointee object as if it had no any base lvalue specified.
3212 // TODO: Support TBAA for member arrays.
3213 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
3214 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3215 if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3217 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3220 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3221 /// array to pointer, return the array subexpression.
3222 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3223 // If this isn't just an array->pointer decay, bail out.
3224 const auto *CE = dyn_cast<CastExpr>(E);
3225 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3228 // If this is a decay from variable width array, bail out.
3229 const Expr *SubExpr = CE->getSubExpr();
3230 if (SubExpr->getType()->isVariableArrayType())
3236 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
3238 ArrayRef<llvm::Value*> indices,
3242 const llvm::Twine &name = "arrayidx") {
3244 return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3245 CodeGenFunction::NotSubtraction, loc,
3248 return CGF.Builder.CreateGEP(ptr, indices, name);
3252 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
3254 CharUnits eltSize) {
3255 // If we have a constant index, we can use the exact offset of the
3256 // element we're accessing.
3257 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3258 CharUnits offset = constantIdx->getZExtValue() * eltSize;
3259 return arrayAlign.alignmentAtOffset(offset);
3261 // Otherwise, use the worst-case alignment for any element.
3263 return arrayAlign.alignmentOfArrayElement(eltSize);
3267 static QualType getFixedSizeElementType(const ASTContext &ctx,
3268 const VariableArrayType *vla) {
3271 eltType = vla->getElementType();
3272 } while ((vla = ctx.getAsVariableArrayType(eltType)));
3276 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
3277 ArrayRef<llvm::Value *> indices,
3278 QualType eltType, bool inbounds,
3279 bool signedIndices, SourceLocation loc,
3280 const llvm::Twine &name = "arrayidx") {
3281 // All the indices except that last must be zero.
3283 for (auto idx : indices.drop_back())
3284 assert(isa<llvm::ConstantInt>(idx) &&
3285 cast<llvm::ConstantInt>(idx)->isZero());
3288 // Determine the element size of the statically-sized base. This is
3289 // the thing that the indices are expressed in terms of.
3290 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3291 eltType = getFixedSizeElementType(CGF.getContext(), vla);
3294 // We can use that to compute the best alignment of the element.
3295 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3296 CharUnits eltAlign =
3297 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3299 llvm::Value *eltPtr = emitArraySubscriptGEP(
3300 CGF, addr.getPointer(), indices, inbounds, signedIndices, loc, name);
3301 return Address(eltPtr, eltAlign);
3304 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3306 // The index must always be an integer, which is not an aggregate. Emit it
3307 // in lexical order (this complexity is, sadly, required by C++17).
3308 llvm::Value *IdxPre =
3309 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3310 bool SignedIndices = false;
3311 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3313 if (E->getLHS() != E->getIdx()) {
3314 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3315 Idx = EmitScalarExpr(E->getIdx());
3318 QualType IdxTy = E->getIdx()->getType();
3319 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3320 SignedIndices |= IdxSigned;
3322 if (SanOpts.has(SanitizerKind::ArrayBounds))
3323 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3325 // Extend or truncate the index type to 32 or 64-bits.
3326 if (Promote && Idx->getType() != IntPtrTy)
3327 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3333 // If the base is a vector type, then we are forming a vector element lvalue
3334 // with this subscript.
3335 if (E->getBase()->getType()->isVectorType() &&
3336 !isa<ExtVectorElementExpr>(E->getBase())) {
3337 // Emit the vector as an lvalue to get its address.
3338 LValue LHS = EmitLValue(E->getBase());
3339 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3340 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3341 return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
3342 LHS.getBaseInfo(), TBAAAccessInfo());
3345 // All the other cases basically behave like simple offsetting.
3347 // Handle the extvector case we ignored above.
3348 if (isa<ExtVectorElementExpr>(E->getBase())) {
3349 LValue LV = EmitLValue(E->getBase());
3350 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3351 Address Addr = EmitExtVectorElementLValue(LV);
3353 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3354 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3355 SignedIndices, E->getExprLoc());
3356 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3357 CGM.getTBAAInfoForSubobject(LV, EltType));
3360 LValueBaseInfo EltBaseInfo;
3361 TBAAAccessInfo EltTBAAInfo;
3362 Address Addr = Address::invalid();
3363 if (const VariableArrayType *vla =
3364 getContext().getAsVariableArrayType(E->getType())) {
3365 // The base must be a pointer, which is not an aggregate. Emit
3366 // it. It needs to be emitted first in case it's what captures
3368 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3369 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3371 // The element count here is the total number of non-VLA elements.
3372 llvm::Value *numElements = getVLASize(vla).NumElts;
3374 // Effectively, the multiply by the VLA size is part of the GEP.
3375 // GEP indexes are signed, and scaling an index isn't permitted to
3376 // signed-overflow, so we use the same semantics for our explicit
3377 // multiply. We suppress this if overflow is not undefined behavior.
3378 if (getLangOpts().isSignedOverflowDefined()) {
3379 Idx = Builder.CreateMul(Idx, numElements);
3381 Idx = Builder.CreateNSWMul(Idx, numElements);
3384 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3385 !getLangOpts().isSignedOverflowDefined(),
3386 SignedIndices, E->getExprLoc());
3388 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3389 // Indexing over an interface, as in "NSString *P; P[4];"
3391 // Emit the base pointer.
3392 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3393 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3395 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3396 llvm::Value *InterfaceSizeVal =
3397 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3399 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3401 // We don't necessarily build correct LLVM struct types for ObjC
3402 // interfaces, so we can't rely on GEP to do this scaling
3403 // correctly, so we need to cast to i8*. FIXME: is this actually
3404 // true? A lot of other things in the fragile ABI would break...
3405 llvm::Type *OrigBaseTy = Addr.getType();
3406 Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3409 CharUnits EltAlign =
3410 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3411 llvm::Value *EltPtr =
3412 emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3413 SignedIndices, E->getExprLoc());
3414 Addr = Address(EltPtr, EltAlign);
3417 Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3418 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3419 // If this is A[i] where A is an array, the frontend will have decayed the
3420 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3421 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3422 // "gep x, i" here. Emit one "gep A, 0, i".
3423 assert(Array->getType()->isArrayType() &&
3424 "Array to pointer decay must have array source type!");
3426 // For simple multidimensional array indexing, set the 'accessed' flag for
3427 // better bounds-checking of the base expression.
3428 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3429 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3431 ArrayLV = EmitLValue(Array);
3432 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3434 // Propagate the alignment from the array itself to the result.
3435 Addr = emitArraySubscriptGEP(
3436 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3437 E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3439 EltBaseInfo = ArrayLV.getBaseInfo();
3440 EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3442 // The base must be a pointer; emit it with an estimate of its alignment.
3443 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3444 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3445 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3446 !getLangOpts().isSignedOverflowDefined(),
3447 SignedIndices, E->getExprLoc());
3450 LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3452 if (getLangOpts().ObjC1 &&
3453 getLangOpts().getGC() != LangOptions::NonGC) {
3454 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3455 setObjCGCLValueClass(getContext(), E, LV);
3460 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
3461 LValueBaseInfo &BaseInfo,
3462 TBAAAccessInfo &TBAAInfo,
3463 QualType BaseTy, QualType ElTy,
3464 bool IsLowerBound) {
3466 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3467 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3468 if (BaseTy->isArrayType()) {
3469 Address Addr = BaseLVal.getAddress();
3470 BaseInfo = BaseLVal.getBaseInfo();
3472 // If the array type was an incomplete type, we need to make sure
3473 // the decay ends up being the right type.
3474 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3475 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3477 // Note that VLA pointers are always decayed, so we don't need to do
3479 if (!BaseTy->isVariableArrayType()) {
3480 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3481 "Expected pointer to array");
3482 Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
3486 return CGF.Builder.CreateElementBitCast(Addr,
3487 CGF.ConvertTypeForMem(ElTy));
3489 LValueBaseInfo TypeBaseInfo;
3490 TBAAAccessInfo TypeTBAAInfo;
3491 CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3493 BaseInfo.mergeForCast(TypeBaseInfo);
3494 TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3495 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3497 return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3500 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3501 bool IsLowerBound) {
3502 QualType BaseTy = OMPArraySectionExpr::getBaseOriginalType(E->getBase());
3503 QualType ResultExprTy;
3504 if (auto *AT = getContext().getAsArrayType(BaseTy))
3505 ResultExprTy = AT->getElementType();
3507 ResultExprTy = BaseTy->getPointeeType();
3508 llvm::Value *Idx = nullptr;
3509 if (IsLowerBound || E->getColonLoc().isInvalid()) {
3510 // Requesting lower bound or upper bound, but without provided length and
3511 // without ':' symbol for the default length -> length = 1.
3512 // Idx = LowerBound ?: 0;
3513 if (auto *LowerBound = E->getLowerBound()) {
3514 Idx = Builder.CreateIntCast(
3515 EmitScalarExpr(LowerBound), IntPtrTy,
3516 LowerBound->getType()->hasSignedIntegerRepresentation());
3518 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3520 // Try to emit length or lower bound as constant. If this is possible, 1
3521 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3522 // IR (LB + Len) - 1.
3523 auto &C = CGM.getContext();
3524 auto *Length = E->getLength();
3525 llvm::APSInt ConstLength;
3527 // Idx = LowerBound + Length - 1;
3528 if (Length->isIntegerConstantExpr(ConstLength, C)) {
3529 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3532 auto *LowerBound = E->getLowerBound();
3533 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3534 if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3535 ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3536 LowerBound = nullptr;
3540 else if (!LowerBound)
3543 if (Length || LowerBound) {
3544 auto *LowerBoundVal =
3546 ? Builder.CreateIntCast(
3547 EmitScalarExpr(LowerBound), IntPtrTy,
3548 LowerBound->getType()->hasSignedIntegerRepresentation())
3549 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3552 ? Builder.CreateIntCast(
3553 EmitScalarExpr(Length), IntPtrTy,
3554 Length->getType()->hasSignedIntegerRepresentation())
3555 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3556 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3558 !getLangOpts().isSignedOverflowDefined());
3559 if (Length && LowerBound) {
3560 Idx = Builder.CreateSub(
3561 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3562 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3565 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3567 // Idx = ArraySize - 1;
3568 QualType ArrayTy = BaseTy->isPointerType()
3569 ? E->getBase()->IgnoreParenImpCasts()->getType()
3571 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3572 Length = VAT->getSizeExpr();
3573 if (Length->isIntegerConstantExpr(ConstLength, C))
3576 auto *CAT = C.getAsConstantArrayType(ArrayTy);
3577 ConstLength = CAT->getSize();
3580 auto *LengthVal = Builder.CreateIntCast(
3581 EmitScalarExpr(Length), IntPtrTy,
3582 Length->getType()->hasSignedIntegerRepresentation());
3583 Idx = Builder.CreateSub(
3584 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3585 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3587 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3589 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3595 Address EltPtr = Address::invalid();
3596 LValueBaseInfo BaseInfo;
3597 TBAAAccessInfo TBAAInfo;
3598 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3599 // The base must be a pointer, which is not an aggregate. Emit
3600 // it. It needs to be emitted first in case it's what captures
3603 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3604 BaseTy, VLA->getElementType(), IsLowerBound);
3605 // The element count here is the total number of non-VLA elements.
3606 llvm::Value *NumElements = getVLASize(VLA).NumElts;
3608 // Effectively, the multiply by the VLA size is part of the GEP.
3609 // GEP indexes are signed, and scaling an index isn't permitted to
3610 // signed-overflow, so we use the same semantics for our explicit
3611 // multiply. We suppress this if overflow is not undefined behavior.
3612 if (getLangOpts().isSignedOverflowDefined())
3613 Idx = Builder.CreateMul(Idx, NumElements);
3615 Idx = Builder.CreateNSWMul(Idx, NumElements);
3616 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3617 !getLangOpts().isSignedOverflowDefined(),
3618 /*SignedIndices=*/false, E->getExprLoc());
3619 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3620 // If this is A[i] where A is an array, the frontend will have decayed the
3621 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3622 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3623 // "gep x, i" here. Emit one "gep A, 0, i".
3624 assert(Array->getType()->isArrayType() &&
3625 "Array to pointer decay must have array source type!");
3627 // For simple multidimensional array indexing, set the 'accessed' flag for
3628 // better bounds-checking of the base expression.
3629 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3630 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3632 ArrayLV = EmitLValue(Array);
3634 // Propagate the alignment from the array itself to the result.
3635 EltPtr = emitArraySubscriptGEP(
3636 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3637 ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3638 /*SignedIndices=*/false, E->getExprLoc());
3639 BaseInfo = ArrayLV.getBaseInfo();
3640 TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3642 Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3643 TBAAInfo, BaseTy, ResultExprTy,
3645 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3646 !getLangOpts().isSignedOverflowDefined(),
3647 /*SignedIndices=*/false, E->getExprLoc());
3650 return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3653 LValue CodeGenFunction::
3654 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
3655 // Emit the base vector as an l-value.
3658 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3660 // If it is a pointer to a vector, emit the address and form an lvalue with
3662 LValueBaseInfo BaseInfo;
3663 TBAAAccessInfo TBAAInfo;
3664 Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3665 const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3666 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3667 Base.getQuals().removeObjCGCAttr();
3668 } else if (E->getBase()->isGLValue()) {
3669 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3670 // emit the base as an lvalue.
3671 assert(E->getBase()->getType()->isVectorType());
3672 Base = EmitLValue(E->getBase());
3674 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3675 assert(E->getBase()->getType()->isVectorType() &&
3676 "Result must be a vector");
3677 llvm::Value *Vec = EmitScalarExpr(E->getBase());
3679 // Store the vector to memory (because LValue wants an address).
3680 Address VecMem = CreateMemTemp(E->getBase()->getType());
3681 Builder.CreateStore(Vec, VecMem);
3682 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3683 AlignmentSource::Decl);
3687 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
3689 // Encode the element access list into a vector of unsigned indices.
3690 SmallVector<uint32_t, 4> Indices;
3691 E->getEncodedElementAccess(Indices);
3693 if (Base.isSimple()) {
3694 llvm::Constant *CV =
3695 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3696 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3697 Base.getBaseInfo(), TBAAAccessInfo());
3699 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3701 llvm::Constant *BaseElts = Base.getExtVectorElts();
3702 SmallVector<llvm::Constant *, 4> CElts;
3704 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3705 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3706 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3707 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
3708 Base.getBaseInfo(), TBAAAccessInfo());
3711 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
3712 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3713 EmitIgnoredExpr(E->getBase());
3714 return EmitDeclRefLValue(DRE);
3717 Expr *BaseExpr = E->getBase();
3718 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3721 LValueBaseInfo BaseInfo;
3722 TBAAAccessInfo TBAAInfo;
3723 Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3724 QualType PtrTy = BaseExpr->getType()->getPointeeType();
3725 SanitizerSet SkippedChecks;
3726 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3728 SkippedChecks.set(SanitizerKind::Alignment, true);
3729 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3730 SkippedChecks.set(SanitizerKind::Null, true);
3731 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3732 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3733 BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3735 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3737 NamedDecl *ND = E->getMemberDecl();
3738 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3739 LValue LV = EmitLValueForField(BaseLV, Field);
3740 setObjCGCLValueClass(getContext(), E, LV);
3744 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3745 return EmitFunctionDeclLValue(*this, E, FD);
3747 llvm_unreachable("Unhandled member declaration!");
3750 /// Given that we are currently emitting a lambda, emit an l-value for
3751 /// one of its members.
3752 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
3753 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3754 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3755 QualType LambdaTagType =
3756 getContext().getTagDeclType(Field->getParent());
3757 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3758 return EmitLValueForField(LambdaLV, Field);
3761 /// Drill down to the storage of a field without walking into
3762 /// reference types.
3764 /// The resulting address doesn't necessarily have the right type.
3765 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
3766 const FieldDecl *field) {
3767 const RecordDecl *rec = field->getParent();
3770 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3773 // Adjust the alignment down to the given offset.
3774 // As a special case, if the LLVM field index is 0, we know that this
3776 assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
3777 .getFieldOffset(field->getFieldIndex()) == 0) &&
3778 "LLVM field at index zero had non-zero offset?");
3780 auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
3781 auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
3782 offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
3785 return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
3788 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3789 const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3793 if (RD->isDynamicClass())
3796 for (const auto &Base : RD->bases())
3797 if (hasAnyVptr(Base.getType(), Context))
3800 for (const FieldDecl *Field : RD->fields())
3801 if (hasAnyVptr(Field->getType(), Context))
3807 LValue CodeGenFunction::EmitLValueForField(LValue base,
3808 const FieldDecl *field) {
3809 LValueBaseInfo BaseInfo = base.getBaseInfo();
3811 if (field->isBitField()) {
3812 const CGRecordLayout &RL =
3813 CGM.getTypes().getCGRecordLayout(field->getParent());
3814 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3815 Address Addr = base.getAddress();
3816 unsigned Idx = RL.getLLVMFieldNo(field);
3818 // For structs, we GEP to the field that the record layout suggests.
3819 Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
3821 // Get the access type.
3822 llvm::Type *FieldIntTy =
3823 llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3824 if (Addr.getElementType() != FieldIntTy)
3825 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3827 QualType fieldType =
3828 field->getType().withCVRQualifiers(base.getVRQualifiers());
3829 // TODO: Support TBAA for bit fields.
3830 LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
3831 return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
3835 // Fields of may-alias structures are may-alias themselves.
3836 // FIXME: this should get propagated down through anonymous structs
3838 QualType FieldType = field->getType();
3839 const RecordDecl *rec = field->getParent();
3840 AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
3841 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
3842 TBAAAccessInfo FieldTBAAInfo;
3843 if (base.getTBAAInfo().isMayAlias() ||
3844 rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
3845 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
3846 } else if (rec->isUnion()) {
3847 // TODO: Support TBAA for unions.
3848 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
3850 // If no base type been assigned for the base access, then try to generate
3851 // one for this base lvalue.
3852 FieldTBAAInfo = base.getTBAAInfo();
3853 if (!FieldTBAAInfo.BaseType) {
3854 FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
3855 assert(!FieldTBAAInfo.Offset &&
3856 "Nonzero offset for an access with no base type!");
3859 // Adjust offset to be relative to the base type.
3860 const ASTRecordLayout &Layout =
3861 getContext().getASTRecordLayout(field->getParent());
3862 unsigned CharWidth = getContext().getCharWidth();
3863 if (FieldTBAAInfo.BaseType)
3864 FieldTBAAInfo.Offset +=
3865 Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
3867 // Update the final access type and size.
3868 FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
3869 FieldTBAAInfo.Size =
3870 getContext().getTypeSizeInChars(FieldType).getQuantity();
3873 Address addr = base.getAddress();
3874 if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
3875 if (CGM.getCodeGenOpts().StrictVTablePointers &&
3876 ClassDef->isDynamicClass()) {
3877 // Getting to any field of dynamic object requires stripping dynamic
3878 // information provided by invariant.group. This is because accessing
3879 // fields may leak the real address of dynamic object, which could result
3880 // in miscompilation when leaked pointer would be compared.
3881 auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
3882 addr = Address(stripped, addr.getAlignment());
3886 unsigned RecordCVR = base.getVRQualifiers();
3887 if (rec->isUnion()) {
3888 // For unions, there is no pointer adjustment.
3889 assert(!FieldType->isReferenceType() && "union has reference member");
3890 if (CGM.getCodeGenOpts().StrictVTablePointers &&
3891 hasAnyVptr(FieldType, getContext()))
3892 // Because unions can easily skip invariant.barriers, we need to add
3893 // a barrier every time CXXRecord field with vptr is referenced.
3894 addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
3895 addr.getAlignment());
3897 // For structs, we GEP to the field that the record layout suggests.
3898 addr = emitAddrOfFieldStorage(*this, addr, field);
3900 // If this is a reference field, load the reference right now.
3901 if (FieldType->isReferenceType()) {
3902 LValue RefLVal = MakeAddrLValue(addr, FieldType, FieldBaseInfo,
3904 if (RecordCVR & Qualifiers::Volatile)
3905 RefLVal.getQuals().setVolatile(true);
3906 addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
3908 // Qualifiers on the struct don't apply to the referencee.
3910 FieldType = FieldType->getPointeeType();
3914 // Make sure that the address is pointing to the right type. This is critical
3915 // for both unions and structs. A union needs a bitcast, a struct element
3916 // will need a bitcast if the LLVM type laid out doesn't match the desired
3918 addr = Builder.CreateElementBitCast(
3919 addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
3921 if (field->hasAttr<AnnotateAttr>())
3922 addr = EmitFieldAnnotations(field, addr);
3924 LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
3925 LV.getQuals().addCVRQualifiers(RecordCVR);
3927 // __weak attribute on a field is ignored.
3928 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3929 LV.getQuals().removeObjCGCAttr();
3935 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
3936 const FieldDecl *Field) {
3937 QualType FieldType = Field->getType();
3939 if (!FieldType->isReferenceType())
3940 return EmitLValueForField(Base, Field);
3942 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3944 // Make sure that the address is pointing to the right type.
3945 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3946 V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3948 // TODO: Generate TBAA information that describes this access as a structure
3949 // member access and not just an access to an object of the field's type. This
3950 // should be similar to what we do in EmitLValueForField().
3951 LValueBaseInfo BaseInfo = Base.getBaseInfo();
3952 AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
3953 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
3954 return MakeAddrLValue(V, FieldType, FieldBaseInfo,
3955 CGM.getTBAAInfoForSubobject(Base, FieldType));
3958 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
3959 if (E->isFileScope()) {
3960 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
3961 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
3963 if (E->getType()->isVariablyModifiedType())
3964 // make sure to emit the VLA size.
3965 EmitVariablyModifiedType(E->getType());
3967 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
3968 const Expr *InitExpr = E->getInitializer();
3969 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
3971 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
3977 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
3978 if (!E->isGLValue())
3979 // Initializing an aggregate temporary in C++11: T{...}.
3980 return EmitAggExprToLValue(E);
3982 // An lvalue initializer list must be initializing a reference.
3983 assert(E->isTransparent() && "non-transparent glvalue init list");
3984 return EmitLValue(E->getInit(0));
3987 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
3988 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
3989 /// LValue is returned and the current block has been terminated.
3990 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
3991 const Expr *Operand) {
3992 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
3993 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
3997 return CGF.EmitLValue(Operand);
4000 LValue CodeGenFunction::
4001 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
4002 if (!expr->isGLValue()) {
4003 // ?: here should be an aggregate.
4004 assert(hasAggregateEvaluationKind(expr->getType()) &&
4005 "Unexpected conditional operator!");
4006 return EmitAggExprToLValue(expr);
4009 OpaqueValueMapping binding(*this, expr);
4011 const Expr *condExpr = expr->getCond();
4013 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4014 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4015 if (!CondExprBool) std::swap(live, dead);
4017 if (!ContainsLabel(dead)) {
4018 // If the true case is live, we need to track its region.
4020 incrementProfileCounter(expr);
4021 return EmitLValue(live);
4025 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4026 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4027 llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4029 ConditionalEvaluation eval(*this);
4030 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4032 // Any temporaries created here are conditional.
4033 EmitBlock(lhsBlock);
4034 incrementProfileCounter(expr);
4036 Optional<LValue> lhs =
4037 EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4040 if (lhs && !lhs->isSimple())
4041 return EmitUnsupportedLValue(expr, "conditional operator");
4043 lhsBlock = Builder.GetInsertBlock();
4045 Builder.CreateBr(contBlock);
4047 // Any temporaries created here are conditional.
4048 EmitBlock(rhsBlock);
4050 Optional<LValue> rhs =
4051 EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4053 if (rhs && !rhs->isSimple())
4054 return EmitUnsupportedLValue(expr, "conditional operator");
4055 rhsBlock = Builder.GetInsertBlock();
4057 EmitBlock(contBlock);
4060 llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
4062 phi->addIncoming(lhs->getPointer(), lhsBlock);
4063 phi->addIncoming(rhs->getPointer(), rhsBlock);
4064 Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4065 AlignmentSource alignSource =
4066 std::max(lhs->getBaseInfo().getAlignmentSource(),
4067 rhs->getBaseInfo().getAlignmentSource());
4068 TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForConditionalOperator(
4069 lhs->getTBAAInfo(), rhs->getTBAAInfo());
4070 return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4073 assert((lhs || rhs) &&
4074 "both operands of glvalue conditional are throw-expressions?");
4075 return lhs ? *lhs : *rhs;
4079 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4080 /// type. If the cast is to a reference, we can have the usual lvalue result,
4081 /// otherwise if a cast is needed by the code generator in an lvalue context,
4082 /// then it must mean that we need the address of an aggregate in order to
4083 /// access one of its members. This can happen for all the reasons that casts
4084 /// are permitted with aggregate result, including noop aggregate casts, and
4085 /// cast from scalar to union.
4086 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
4087 switch (E->getCastKind()) {
4090 case CK_ArrayToPointerDecay:
4091 case CK_FunctionToPointerDecay:
4092 case CK_NullToMemberPointer:
4093 case CK_NullToPointer:
4094 case CK_IntegralToPointer:
4095 case CK_PointerToIntegral:
4096 case CK_PointerToBoolean:
4097 case CK_VectorSplat:
4098 case CK_IntegralCast:
4099 case CK_BooleanToSignedIntegral:
4100 case CK_IntegralToBoolean:
4101 case CK_IntegralToFloating:
4102 case CK_FloatingToIntegral:
4103 case CK_FloatingToBoolean:
4104 case CK_FloatingCast:
4105 case CK_FloatingRealToComplex:
4106 case CK_FloatingComplexToReal:
4107 case CK_FloatingComplexToBoolean:
4108 case CK_FloatingComplexCast:
4109 case CK_FloatingComplexToIntegralComplex:
4110 case CK_IntegralRealToComplex:
4111 case CK_IntegralComplexToReal:
4112 case CK_IntegralComplexToBoolean:
4113 case CK_IntegralComplexCast:
4114 case CK_IntegralComplexToFloatingComplex:
4115 case CK_DerivedToBaseMemberPointer:
4116 case CK_BaseToDerivedMemberPointer:
4117 case CK_MemberPointerToBoolean:
4118 case CK_ReinterpretMemberPointer:
4119 case CK_AnyPointerToBlockPointerCast:
4120 case CK_ARCProduceObject:
4121 case CK_ARCConsumeObject:
4122 case CK_ARCReclaimReturnedObject:
4123 case CK_ARCExtendBlockObject:
4124 case CK_CopyAndAutoreleaseBlockObject:
4125 case CK_AddressSpaceConversion:
4126 case CK_IntToOCLSampler:
4127 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4130 llvm_unreachable("dependent cast kind in IR gen!");
4132 case CK_BuiltinFnToFnPtr:
4133 llvm_unreachable("builtin functions are handled elsewhere");
4135 // These are never l-values; just use the aggregate emission code.
4136 case CK_NonAtomicToAtomic:
4137 case CK_AtomicToNonAtomic:
4138 return EmitAggExprToLValue(E);
4141 LValue LV = EmitLValue(E->getSubExpr());
4142 Address V = LV.getAddress();
4143 const auto *DCE = cast<CXXDynamicCastExpr>(E);
4144 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4147 case CK_ConstructorConversion:
4148 case CK_UserDefinedConversion:
4149 case CK_CPointerToObjCPointerCast:
4150 case CK_BlockPointerToObjCPointerCast:
4152 case CK_LValueToRValue:
4153 return EmitLValue(E->getSubExpr());
4155 case CK_UncheckedDerivedToBase:
4156 case CK_DerivedToBase: {
4157 const RecordType *DerivedClassTy =
4158 E->getSubExpr()->getType()->getAs<RecordType>();
4159 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4161 LValue LV = EmitLValue(E->getSubExpr());
4162 Address This = LV.getAddress();
4164 // Perform the derived-to-base conversion
4165 Address Base = GetAddressOfBaseClass(
4166 This, DerivedClassDecl, E->path_begin(), E->path_end(),
4167 /*NullCheckValue=*/false, E->getExprLoc());
4169 // TODO: Support accesses to members of base classes in TBAA. For now, we
4170 // conservatively pretend that the complete object is of the base class
4172 return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4173 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4176 return EmitAggExprToLValue(E);
4177 case CK_BaseToDerived: {
4178 const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
4179 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4181 LValue LV = EmitLValue(E->getSubExpr());
4183 // Perform the base-to-derived conversion
4185 GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
4186 E->path_begin(), E->path_end(),
4187 /*NullCheckValue=*/false);
4189 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4190 // performed and the object is not of the derived type.
4191 if (sanitizePerformTypeCheck())
4192 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
4193 Derived.getPointer(), E->getType());
4195 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4196 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4197 /*MayBeNull=*/false,
4198 CFITCK_DerivedCast, E->getLocStart());
4200 return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4201 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4203 case CK_LValueBitCast: {
4204 // This must be a reinterpret_cast (or c-style equivalent).
4205 const auto *CE = cast<ExplicitCastExpr>(E);
4207 CGM.EmitExplicitCastExprType(CE, this);
4208 LValue LV = EmitLValue(E->getSubExpr());
4209 Address V = Builder.CreateBitCast(LV.getAddress(),
4210 ConvertType(CE->getTypeAsWritten()));
4212 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4213 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4214 /*MayBeNull=*/false,
4215 CFITCK_UnrelatedCast, E->getLocStart());
4217 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4218 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4220 case CK_ObjCObjectLValueCast: {
4221 LValue LV = EmitLValue(E->getSubExpr());
4222 Address V = Builder.CreateElementBitCast(LV.getAddress(),
4223 ConvertType(E->getType()));
4224 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4225 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4227 case CK_ZeroToOCLQueue:
4228 llvm_unreachable("NULL to OpenCL queue lvalue cast is not valid");
4229 case CK_ZeroToOCLEvent:
4230 llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
4233 llvm_unreachable("Unhandled lvalue cast kind?");
4236 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
4237 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
4238 return getOrCreateOpaqueLValueMapping(e);
4242 CodeGenFunction::getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e) {
4243 assert(OpaqueValueMapping::shouldBindAsLValue(e));
4245 llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4246 it = OpaqueLValues.find(e);
4248 if (it != OpaqueLValues.end())
4251 assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4252 return EmitLValue(e->getSourceExpr());
4256 CodeGenFunction::getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e) {
4257 assert(!OpaqueValueMapping::shouldBindAsLValue(e));
4259 llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4260 it = OpaqueRValues.find(e);
4262 if (it != OpaqueRValues.end())
4265 assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4266 return EmitAnyExpr(e->getSourceExpr());
4269 RValue CodeGenFunction::EmitRValueForField(LValue LV,
4270 const FieldDecl *FD,
4271 SourceLocation Loc) {
4272 QualType FT = FD->getType();
4273 LValue FieldLV = EmitLValueForField(LV, FD);
4274 switch (getEvaluationKind(FT)) {
4276 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4278 return FieldLV.asAggregateRValue();
4280 // This routine is used to load fields one-by-one to perform a copy, so
4281 // don't load reference fields.
4282 if (FD->getType()->isReferenceType())
4283 return RValue::get(FieldLV.getPointer());
4284 return EmitLoadOfLValue(FieldLV, Loc);
4286 llvm_unreachable("bad evaluation kind");
4289 //===--------------------------------------------------------------------===//
4290 // Expression Emission
4291 //===--------------------------------------------------------------------===//
4293 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
4294 ReturnValueSlot ReturnValue) {
4295 // Builtins never have block type.
4296 if (E->getCallee()->getType()->isBlockPointerType())
4297 return EmitBlockCallExpr(E, ReturnValue);
4299 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4300 return EmitCXXMemberCallExpr(CE, ReturnValue);
4302 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4303 return EmitCUDAKernelCallExpr(CE, ReturnValue);
4305 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4306 if (const CXXMethodDecl *MD =
4307 dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4308 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4310 CGCallee callee = EmitCallee(E->getCallee());
4312 if (callee.isBuiltin()) {
4313 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4317 if (callee.isPseudoDestructor()) {
4318 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
4321 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4324 /// Emit a CallExpr without considering whether it might be a subclass.
4325 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
4326 ReturnValueSlot ReturnValue) {
4327 CGCallee Callee = EmitCallee(E->getCallee());
4328 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4331 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
4332 if (auto builtinID = FD->getBuiltinID()) {
4333 return CGCallee::forBuiltin(builtinID, FD);
4336 llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4337 return CGCallee::forDirect(calleePtr, FD);
4340 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
4341 E = E->IgnoreParens();
4343 // Look through function-to-pointer decay.
4344 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4345 if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4346 ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4347 return EmitCallee(ICE->getSubExpr());
4350 // Resolve direct calls.
4351 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4352 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4353 return EmitDirectCallee(*this, FD);
4355 } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4356 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4357 EmitIgnoredExpr(ME->getBase());
4358 return EmitDirectCallee(*this, FD);
4361 // Look through template substitutions.
4362 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4363 return EmitCallee(NTTP->getReplacement());
4365 // Treat pseudo-destructor calls differently.
4366 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4367 return CGCallee::forPseudoDestructor(PDE);
4370 // Otherwise, we have an indirect reference.
4371 llvm::Value *calleePtr;
4372 QualType functionType;
4373 if (auto ptrType = E->getType()->getAs<PointerType>()) {
4374 calleePtr = EmitScalarExpr(E);
4375 functionType = ptrType->getPointeeType();
4377 functionType = E->getType();
4378 calleePtr = EmitLValue(E).getPointer();
4380 assert(functionType->isFunctionType());
4381 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(),
4382 E->getReferencedDeclOfCallee());
4383 CGCallee callee(calleeInfo, calleePtr);
4387 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
4388 // Comma expressions just emit their LHS then their RHS as an l-value.
4389 if (E->getOpcode() == BO_Comma) {
4390 EmitIgnoredExpr(E->getLHS());
4391 EnsureInsertPoint();
4392 return EmitLValue(E->getRHS());
4395 if (E->getOpcode() == BO_PtrMemD ||
4396 E->getOpcode() == BO_PtrMemI)
4397 return EmitPointerToDataMemberBinaryExpr(E);
4399 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4401 // Note that in all of these cases, __block variables need the RHS
4402 // evaluated first just in case the variable gets moved by the RHS.
4404 switch (getEvaluationKind(E->getType())) {
4406 switch (E->getLHS()->getType().getObjCLifetime()) {
4407 case Qualifiers::OCL_Strong:
4408 return EmitARCStoreStrong(E, /*ignored*/ false).first;
4410 case Qualifiers::OCL_Autoreleasing:
4411 return EmitARCStoreAutoreleasing(E).first;
4413 // No reason to do any of these differently.
4414 case Qualifiers::OCL_None:
4415 case Qualifiers::OCL_ExplicitNone:
4416 case Qualifiers::OCL_Weak:
4420 RValue RV = EmitAnyExpr(E->getRHS());
4421 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
4423 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
4424 EmitStoreThroughLValue(RV, LV);
4429 return EmitComplexAssignmentLValue(E);
4432 return EmitAggExprToLValue(E);
4434 llvm_unreachable("bad evaluation kind");
4437 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
4438 RValue RV = EmitCallExpr(E);
4441 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4442 AlignmentSource::Decl);
4444 assert(E->getCallReturnType(getContext())->isReferenceType() &&
4445 "Can't have a scalar return unless the return type is a "
4448 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4451 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
4452 // FIXME: This shouldn't require another copy.
4453 return EmitAggExprToLValue(E);
4456 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
4457 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
4458 && "binding l-value to type which needs a temporary");
4459 AggValueSlot Slot = CreateAggTemp(E->getType());
4460 EmitCXXConstructExpr(E, Slot);
4461 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4465 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
4466 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
4469 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
4470 return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
4471 ConvertType(E->getType()));
4474 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
4475 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4476 AlignmentSource::Decl);
4480 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
4481 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4482 Slot.setExternallyDestructed();
4483 EmitAggExpr(E->getSubExpr(), Slot);
4484 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4485 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4489 CodeGenFunction::EmitLambdaLValue(const LambdaExpr *E) {
4490 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4491 EmitLambdaExpr(E, Slot);
4492 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4495 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
4496 RValue RV = EmitObjCMessageExpr(E);
4499 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4500 AlignmentSource::Decl);
4502 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4503 "Can't have a scalar return unless the return type is a "
4506 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4509 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
4511 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
4512 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4515 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
4516 const ObjCIvarDecl *Ivar) {
4517 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4520 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
4521 llvm::Value *BaseValue,
4522 const ObjCIvarDecl *Ivar,
4523 unsigned CVRQualifiers) {
4524 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4525 Ivar, CVRQualifiers);
4528 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
4529 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4530 llvm::Value *BaseValue = nullptr;
4531 const Expr *BaseExpr = E->getBase();
4532 Qualifiers BaseQuals;
4535 BaseValue = EmitScalarExpr(BaseExpr);
4536 ObjectTy = BaseExpr->getType()->getPointeeType();
4537 BaseQuals = ObjectTy.getQualifiers();
4539 LValue BaseLV = EmitLValue(BaseExpr);
4540 BaseValue = BaseLV.getPointer();
4541 ObjectTy = BaseExpr->getType();
4542 BaseQuals = ObjectTy.getQualifiers();
4546 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4547 BaseQuals.getCVRQualifiers());
4548 setObjCGCLValueClass(getContext(), E, LV);
4552 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
4553 // Can only get l-value for message expression returning aggregate type
4554 RValue RV = EmitAnyExprToTemp(E);
4555 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4556 AlignmentSource::Decl);
4559 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4560 const CallExpr *E, ReturnValueSlot ReturnValue,
4561 llvm::Value *Chain) {
4562 // Get the actual function type. The callee type will always be a pointer to
4563 // function type or a block pointer type.
4564 assert(CalleeType->isFunctionPointerType() &&
4565 "Call must have function pointer type!");
4567 const Decl *TargetDecl = OrigCallee.getAbstractInfo().getCalleeDecl();
4569 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
4570 // We can only guarantee that a function is called from the correct
4571 // context/function based on the appropriate target attributes,
4572 // so only check in the case where we have both always_inline and target
4573 // since otherwise we could be making a conditional call after a check for
4574 // the proper cpu features (and it won't cause code generation issues due to
4575 // function based code generation).
4576 if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
4577 TargetDecl->hasAttr<TargetAttr>())
4578 checkTargetFeatures(E, FD);
4580 CalleeType = getContext().getCanonicalType(CalleeType);
4582 auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
4584 CGCallee Callee = OrigCallee;
4586 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4587 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4588 if (llvm::Constant *PrefixSig =
4589 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
4590 SanitizerScope SanScope(this);
4591 // Remove any (C++17) exception specifications, to allow calling e.g. a
4592 // noexcept function through a non-noexcept pointer.
4594 getContext().getFunctionTypeWithExceptionSpec(PointeeType, EST_None);
4595 llvm::Constant *FTRTTIConst =
4596 CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
4597 llvm::Type *PrefixStructTyElems[] = {PrefixSig->getType(), Int32Ty};
4598 llvm::StructType *PrefixStructTy = llvm::StructType::get(
4599 CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4601 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4603 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4604 CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4605 llvm::Value *CalleeSigPtr =
4606 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4607 llvm::Value *CalleeSig =
4608 Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4609 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4611 llvm::BasicBlock *Cont = createBasicBlock("cont");
4612 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4613 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4615 EmitBlock(TypeCheck);
4616 llvm::Value *CalleeRTTIPtr =
4617 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4618 llvm::Value *CalleeRTTIEncoded =
4619 Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4620 llvm::Value *CalleeRTTI =
4621 DecodeAddrUsedInPrologue(CalleePtr, CalleeRTTIEncoded);
4622 llvm::Value *CalleeRTTIMatch =
4623 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4624 llvm::Constant *StaticData[] = {
4625 EmitCheckSourceLocation(E->getLocStart()),
4626 EmitCheckTypeDescriptor(CalleeType)
4628 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4629 SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
4631 Builder.CreateBr(Cont);
4636 const auto *FnType = cast<FunctionType>(PointeeType);
4638 // If we are checking indirect calls and this call is indirect, check that the
4639 // function pointer is a member of the bit set for the function type.
4640 if (SanOpts.has(SanitizerKind::CFIICall) &&
4641 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4642 SanitizerScope SanScope(this);
4643 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4646 if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
4647 MD = CGM.CreateMetadataIdentifierGeneralized(QualType(FnType, 0));
4649 MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4651 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4653 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4654 llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4655 llvm::Value *TypeTest = Builder.CreateCall(
4656 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4658 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4659 llvm::Constant *StaticData[] = {
4660 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4661 EmitCheckSourceLocation(E->getLocStart()),
4662 EmitCheckTypeDescriptor(QualType(FnType, 0)),
4664 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4665 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4666 CastedCallee, StaticData);
4668 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4669 SanitizerHandler::CFICheckFail, StaticData,
4670 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4676 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
4677 CGM.getContext().VoidPtrTy);
4679 // C++17 requires that we evaluate arguments to a call using assignment syntax
4680 // right-to-left, and that we evaluate arguments to certain other operators
4681 // left-to-right. Note that we allow this to override the order dictated by
4682 // the calling convention on the MS ABI, which means that parameter
4683 // destruction order is not necessarily reverse construction order.
4684 // FIXME: Revisit this based on C++ committee response to unimplementability.
4685 EvaluationOrder Order = EvaluationOrder::Default;
4686 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4687 if (OCE->isAssignmentOp())
4688 Order = EvaluationOrder::ForceRightToLeft;
4690 switch (OCE->getOperator()) {
4692 case OO_GreaterGreater:
4697 Order = EvaluationOrder::ForceLeftToRight;
4705 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4706 E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4708 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
4709 Args, FnType, /*isChainCall=*/Chain);
4712 // If the expression that denotes the called function has a type
4713 // that does not include a prototype, [the default argument
4714 // promotions are performed]. If the number of arguments does not
4715 // equal the number of parameters, the behavior is undefined. If
4716 // the function is defined with a type that includes a prototype,
4717 // and either the prototype ends with an ellipsis (, ...) or the
4718 // types of the arguments after promotion are not compatible with
4719 // the types of the parameters, the behavior is undefined. If the
4720 // function is defined with a type that does not include a
4721 // prototype, and the types of the arguments after promotion are
4722 // not compatible with those of the parameters after promotion,
4723 // the behavior is undefined [except in some trivial cases].
4724 // That is, in the general case, we should assume that a call
4725 // through an unprototyped function type works like a *non-variadic*
4726 // call. The way we make this work is to cast to the exact type
4727 // of the promoted arguments.
4729 // Chain calls use this same code path to add the invisible chain parameter
4730 // to the function type.
4731 if (isa<FunctionNoProtoType>(FnType) || Chain) {
4732 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4733 CalleeTy = CalleeTy->getPointerTo();
4735 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4736 CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
4737 Callee.setFunctionPointer(CalleePtr);
4740 return EmitCall(FnInfo, Callee, ReturnValue, Args, nullptr, E->getExprLoc());
4743 LValue CodeGenFunction::
4744 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
4745 Address BaseAddr = Address::invalid();
4746 if (E->getOpcode() == BO_PtrMemI) {
4747 BaseAddr = EmitPointerWithAlignment(E->getLHS());
4749 BaseAddr = EmitLValue(E->getLHS()).getAddress();
4752 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4754 const MemberPointerType *MPT
4755 = E->getRHS()->getType()->getAs<MemberPointerType>();
4757 LValueBaseInfo BaseInfo;
4758 TBAAAccessInfo TBAAInfo;
4759 Address MemberAddr =
4760 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo,
4763 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo);
4766 /// Given the address of a temporary variable, produce an r-value of
4768 RValue CodeGenFunction::convertTempToRValue(Address addr,
4770 SourceLocation loc) {
4771 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
4772 switch (getEvaluationKind(type)) {
4774 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4776 return lvalue.asAggregateRValue();
4778 return RValue::get(EmitLoadOfScalar(lvalue, loc));
4780 llvm_unreachable("bad evaluation kind");
4783 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4784 assert(Val->getType()->isFPOrFPVectorTy());
4785 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4788 llvm::MDBuilder MDHelper(getLLVMContext());
4789 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
4791 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
4795 struct LValueOrRValue {
4801 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
4802 const PseudoObjectExpr *E,
4804 AggValueSlot slot) {
4805 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
4807 // Find the result expression, if any.
4808 const Expr *resultExpr = E->getResultExpr();
4809 LValueOrRValue result;
4811 for (PseudoObjectExpr::const_semantics_iterator
4812 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
4813 const Expr *semantic = *i;
4815 // If this semantic expression is an opaque value, bind it
4816 // to the result of its source expression.
4817 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
4818 // Skip unique OVEs.
4819 if (ov->isUnique()) {
4820 assert(ov != resultExpr &&
4821 "A unique OVE cannot be used as the result expression");
4825 // If this is the result expression, we may need to evaluate
4826 // directly into the slot.
4827 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
4829 if (ov == resultExpr && ov->isRValue() && !forLValue &&
4830 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
4831 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
4832 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
4833 AlignmentSource::Decl);
4834 opaqueData = OVMA::bind(CGF, ov, LV);
4835 result.RV = slot.asRValue();
4837 // Otherwise, emit as normal.
4839 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
4841 // If this is the result, also evaluate the result now.
4842 if (ov == resultExpr) {
4844 result.LV = CGF.EmitLValue(ov);
4846 result.RV = CGF.EmitAnyExpr(ov, slot);
4850 opaques.push_back(opaqueData);
4852 // Otherwise, if the expression is the result, evaluate it
4853 // and remember the result.
4854 } else if (semantic == resultExpr) {
4856 result.LV = CGF.EmitLValue(semantic);
4858 result.RV = CGF.EmitAnyExpr(semantic, slot);
4860 // Otherwise, evaluate the expression in an ignored context.
4862 CGF.EmitIgnoredExpr(semantic);
4866 // Unbind all the opaques now.
4867 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
4868 opaques[i].unbind(CGF);
4873 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
4874 AggValueSlot slot) {
4875 return emitPseudoObjectExpr(*this, E, false, slot).RV;
4878 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
4879 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;