1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This contains code to emit Expr nodes as LLVM code.
12 //===----------------------------------------------------------------------===//
16 #include "CGCleanup.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "CGOpenMPRuntime.h"
20 #include "CGRecordLayout.h"
21 #include "CodeGenFunction.h"
22 #include "CodeGenModule.h"
23 #include "TargetInfo.h"
24 #include "clang/AST/ASTContext.h"
25 #include "clang/AST/Attr.h"
26 #include "clang/AST/DeclObjC.h"
27 #include "clang/AST/NSAPI.h"
28 #include "clang/Frontend/CodeGenOptions.h"
29 #include "llvm/ADT/Hashing.h"
30 #include "llvm/ADT/StringExtras.h"
31 #include "llvm/IR/DataLayout.h"
32 #include "llvm/IR/Intrinsics.h"
33 #include "llvm/IR/LLVMContext.h"
34 #include "llvm/IR/MDBuilder.h"
35 #include "llvm/Support/ConvertUTF.h"
36 #include "llvm/Support/MathExtras.h"
37 #include "llvm/Support/Path.h"
38 #include "llvm/Transforms/Utils/SanitizerStats.h"
42 using namespace clang;
43 using namespace CodeGen;
45 //===--------------------------------------------------------------------===//
46 // Miscellaneous Helper Methods
47 //===--------------------------------------------------------------------===//
49 llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
50 unsigned addressSpace =
51 cast<llvm::PointerType>(value->getType())->getAddressSpace();
53 llvm::PointerType *destType = Int8PtrTy;
55 destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
57 if (value->getType() == destType) return value;
58 return Builder.CreateBitCast(value, destType);
61 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
63 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
65 auto Alloca = CreateTempAlloca(Ty, Name);
66 Alloca->setAlignment(Align.getQuantity());
67 return Address(Alloca, Align);
70 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
72 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
74 return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
75 nullptr, Name, AllocaInsertPt);
78 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
79 /// default alignment of the corresponding LLVM type, which is *not*
80 /// guaranteed to be related in any way to the expected alignment of
81 /// an AST type that might have been lowered to Ty.
82 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
85 CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
86 return CreateTempAlloca(Ty, Align, Name);
89 void CodeGenFunction::InitTempAlloca(Address Var, llvm::Value *Init) {
90 assert(isa<llvm::AllocaInst>(Var.getPointer()));
91 auto *Store = new llvm::StoreInst(Init, Var.getPointer());
92 Store->setAlignment(Var.getAlignment().getQuantity());
93 llvm::BasicBlock *Block = AllocaInsertPt->getParent();
94 Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
97 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
98 CharUnits Align = getContext().getTypeAlignInChars(Ty);
99 return CreateTempAlloca(ConvertType(Ty), Align, Name);
102 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name) {
103 // FIXME: Should we prefer the preferred type alignment here?
104 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name);
107 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
109 return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name);
112 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
113 /// expression and compare the result against zero, returning an Int1Ty value.
114 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
115 PGO.setCurrentStmt(E);
116 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
117 llvm::Value *MemPtr = EmitScalarExpr(E);
118 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
121 QualType BoolTy = getContext().BoolTy;
122 SourceLocation Loc = E->getExprLoc();
123 if (!E->getType()->isAnyComplexType())
124 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
126 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
130 /// EmitIgnoredExpr - Emit code to compute the specified expression,
131 /// ignoring the result.
132 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
134 return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
136 // Just emit it as an l-value and drop the result.
140 /// EmitAnyExpr - Emit code to compute the specified expression which
141 /// can have any type. The result is returned as an RValue struct.
142 /// If this is an aggregate expression, AggSlot indicates where the
143 /// result should be returned.
144 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
145 AggValueSlot aggSlot,
147 switch (getEvaluationKind(E->getType())) {
149 return RValue::get(EmitScalarExpr(E, ignoreResult));
151 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
153 if (!ignoreResult && aggSlot.isIgnored())
154 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
155 EmitAggExpr(E, aggSlot);
156 return aggSlot.asRValue();
158 llvm_unreachable("bad evaluation kind");
161 /// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
162 /// always be accessible even if no aggregate location is provided.
163 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
164 AggValueSlot AggSlot = AggValueSlot::ignored();
166 if (hasAggregateEvaluationKind(E->getType()))
167 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
168 return EmitAnyExpr(E, AggSlot);
171 /// EmitAnyExprToMem - Evaluate an expression into a given memory
173 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
177 // FIXME: This function should take an LValue as an argument.
178 switch (getEvaluationKind(E->getType())) {
180 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
184 case TEK_Aggregate: {
185 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
186 AggValueSlot::IsDestructed_t(IsInit),
187 AggValueSlot::DoesNotNeedGCBarriers,
188 AggValueSlot::IsAliased_t(!IsInit)));
193 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
194 LValue LV = MakeAddrLValue(Location, E->getType());
195 EmitStoreThroughLValue(RV, LV);
199 llvm_unreachable("bad evaluation kind");
203 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
204 const Expr *E, Address ReferenceTemporary) {
205 // Objective-C++ ARC:
206 // If we are binding a reference to a temporary that has ownership, we
207 // need to perform retain/release operations on the temporary.
209 // FIXME: This should be looking at E, not M.
210 if (auto Lifetime = M->getType().getObjCLifetime()) {
212 case Qualifiers::OCL_None:
213 case Qualifiers::OCL_ExplicitNone:
214 // Carry on to normal cleanup handling.
217 case Qualifiers::OCL_Autoreleasing:
218 // Nothing to do; cleaned up by an autorelease pool.
221 case Qualifiers::OCL_Strong:
222 case Qualifiers::OCL_Weak:
223 switch (StorageDuration Duration = M->getStorageDuration()) {
225 // Note: we intentionally do not register a cleanup to release
226 // the object on program termination.
230 // FIXME: We should probably register a cleanup in this case.
234 case SD_FullExpression:
235 CodeGenFunction::Destroyer *Destroy;
236 CleanupKind CleanupKind;
237 if (Lifetime == Qualifiers::OCL_Strong) {
238 const ValueDecl *VD = M->getExtendingDecl();
240 VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
241 CleanupKind = CGF.getARCCleanupKind();
242 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
243 : &CodeGenFunction::destroyARCStrongImprecise;
245 // __weak objects always get EH cleanups; otherwise, exceptions
246 // could cause really nasty crashes instead of mere leaks.
247 CleanupKind = NormalAndEHCleanup;
248 Destroy = &CodeGenFunction::destroyARCWeak;
250 if (Duration == SD_FullExpression)
251 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
252 M->getType(), *Destroy,
253 CleanupKind & EHCleanup);
255 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
257 *Destroy, CleanupKind & EHCleanup);
261 llvm_unreachable("temporary cannot have dynamic storage duration");
263 llvm_unreachable("unknown storage duration");
267 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
268 if (const RecordType *RT =
269 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
270 // Get the destructor for the reference temporary.
271 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
272 if (!ClassDecl->hasTrivialDestructor())
273 ReferenceTemporaryDtor = ClassDecl->getDestructor();
276 if (!ReferenceTemporaryDtor)
279 // Call the destructor for the temporary.
280 switch (M->getStorageDuration()) {
283 llvm::Constant *CleanupFn;
284 llvm::Constant *CleanupArg;
285 if (E->getType()->isArrayType()) {
286 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
287 ReferenceTemporary, E->getType(),
288 CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
289 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
290 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
292 CleanupFn = CGF.CGM.getAddrOfCXXStructor(ReferenceTemporaryDtor,
293 StructorType::Complete);
294 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
296 CGF.CGM.getCXXABI().registerGlobalDtor(
297 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
301 case SD_FullExpression:
302 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
303 CodeGenFunction::destroyCXXObject,
304 CGF.getLangOpts().Exceptions);
308 CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
309 ReferenceTemporary, E->getType(),
310 CodeGenFunction::destroyCXXObject,
311 CGF.getLangOpts().Exceptions);
315 llvm_unreachable("temporary cannot have dynamic storage duration");
320 createReferenceTemporary(CodeGenFunction &CGF,
321 const MaterializeTemporaryExpr *M, const Expr *Inner) {
322 switch (M->getStorageDuration()) {
323 case SD_FullExpression:
325 // If we have a constant temporary array or record try to promote it into a
326 // constant global under the same rules a normal constant would've been
327 // promoted. This is easier on the optimizer and generally emits fewer
329 QualType Ty = Inner->getType();
330 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
331 (Ty->isArrayType() || Ty->isRecordType()) &&
332 CGF.CGM.isTypeConstant(Ty, true))
333 if (llvm::Constant *Init = CGF.CGM.EmitConstantExpr(Inner, Ty, &CGF)) {
334 auto *GV = new llvm::GlobalVariable(
335 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
336 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp");
337 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
338 GV->setAlignment(alignment.getQuantity());
339 // FIXME: Should we put the new global into a COMDAT?
340 return Address(GV, alignment);
342 return CGF.CreateMemTemp(Ty, "ref.tmp");
346 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
349 llvm_unreachable("temporary can't have dynamic storage duration");
351 llvm_unreachable("unknown storage duration");
354 LValue CodeGenFunction::
355 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
356 const Expr *E = M->GetTemporaryExpr();
358 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
359 // as that will cause the lifetime adjustment to be lost for ARC
360 auto ownership = M->getType().getObjCLifetime();
361 if (ownership != Qualifiers::OCL_None &&
362 ownership != Qualifiers::OCL_ExplicitNone) {
363 Address Object = createReferenceTemporary(*this, M, E);
364 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
365 Object = Address(llvm::ConstantExpr::getBitCast(Var,
366 ConvertTypeForMem(E->getType())
367 ->getPointerTo(Object.getAddressSpace())),
368 Object.getAlignment());
370 // createReferenceTemporary will promote the temporary to a global with a
371 // constant initializer if it can. It can only do this to a value of
372 // ARC-manageable type if the value is global and therefore "immune" to
373 // ref-counting operations. Therefore we have no need to emit either a
374 // dynamic initialization or a cleanup and we can just return the address
376 if (Var->hasInitializer())
377 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
379 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
381 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
382 AlignmentSource::Decl);
384 switch (getEvaluationKind(E->getType())) {
385 default: llvm_unreachable("expected scalar or aggregate expression");
387 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
389 case TEK_Aggregate: {
390 EmitAggExpr(E, AggValueSlot::forAddr(Object,
391 E->getType().getQualifiers(),
392 AggValueSlot::IsDestructed,
393 AggValueSlot::DoesNotNeedGCBarriers,
394 AggValueSlot::IsNotAliased));
399 pushTemporaryCleanup(*this, M, E, Object);
403 SmallVector<const Expr *, 2> CommaLHSs;
404 SmallVector<SubobjectAdjustment, 2> Adjustments;
405 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
407 for (const auto &Ignored : CommaLHSs)
408 EmitIgnoredExpr(Ignored);
410 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
411 if (opaque->getType()->isRecordType()) {
412 assert(Adjustments.empty());
413 return EmitOpaqueValueLValue(opaque);
417 // Create and initialize the reference temporary.
418 Address Object = createReferenceTemporary(*this, M, E);
419 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
420 Object = Address(llvm::ConstantExpr::getBitCast(
421 Var, ConvertTypeForMem(E->getType())->getPointerTo()),
422 Object.getAlignment());
423 // If the temporary is a global and has a constant initializer or is a
424 // constant temporary that we promoted to a global, we may have already
426 if (!Var->hasInitializer()) {
427 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
428 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
431 switch (M->getStorageDuration()) {
433 case SD_FullExpression:
434 if (auto *Size = EmitLifetimeStart(
435 CGM.getDataLayout().getTypeAllocSize(Object.getElementType()),
436 Object.getPointer())) {
437 if (M->getStorageDuration() == SD_Automatic)
438 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
441 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Object,
448 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
450 pushTemporaryCleanup(*this, M, E, Object);
452 // Perform derived-to-base casts and/or field accesses, to get from the
453 // temporary object we created (and, potentially, for which we extended
454 // the lifetime) to the subobject we're binding the reference to.
455 for (unsigned I = Adjustments.size(); I != 0; --I) {
456 SubobjectAdjustment &Adjustment = Adjustments[I-1];
457 switch (Adjustment.Kind) {
458 case SubobjectAdjustment::DerivedToBaseAdjustment:
460 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
461 Adjustment.DerivedToBase.BasePath->path_begin(),
462 Adjustment.DerivedToBase.BasePath->path_end(),
463 /*NullCheckValue=*/ false, E->getExprLoc());
466 case SubobjectAdjustment::FieldAdjustment: {
467 LValue LV = MakeAddrLValue(Object, E->getType(),
468 AlignmentSource::Decl);
469 LV = EmitLValueForField(LV, Adjustment.Field);
470 assert(LV.isSimple() &&
471 "materialized temporary field is not a simple lvalue");
472 Object = LV.getAddress();
476 case SubobjectAdjustment::MemberPointerAdjustment: {
477 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
478 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
485 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
489 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
490 // Emit the expression as an lvalue.
491 LValue LV = EmitLValue(E);
492 assert(LV.isSimple());
493 llvm::Value *Value = LV.getPointer();
495 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
496 // C++11 [dcl.ref]p5 (as amended by core issue 453):
497 // If a glvalue to which a reference is directly bound designates neither
498 // an existing object or function of an appropriate type nor a region of
499 // storage of suitable size and alignment to contain an object of the
500 // reference's type, the behavior is undefined.
501 QualType Ty = E->getType();
502 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
505 return RValue::get(Value);
509 /// getAccessedFieldNo - Given an encoded value and a result number, return the
510 /// input field number being accessed.
511 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
512 const llvm::Constant *Elts) {
513 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
517 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
518 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
520 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
521 llvm::Value *K47 = Builder.getInt64(47);
522 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
523 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
524 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
525 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
526 return Builder.CreateMul(B1, KMul);
529 bool CodeGenFunction::sanitizePerformTypeCheck() const {
530 return SanOpts.has(SanitizerKind::Null) |
531 SanOpts.has(SanitizerKind::Alignment) |
532 SanOpts.has(SanitizerKind::ObjectSize) |
533 SanOpts.has(SanitizerKind::Vptr);
536 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
537 llvm::Value *Ptr, QualType Ty,
539 SanitizerSet SkippedChecks) {
540 if (!sanitizePerformTypeCheck())
543 // Don't check pointers outside the default address space. The null check
544 // isn't correct, the object-size check isn't supported by LLVM, and we can't
545 // communicate the addresses to the runtime handler for the vptr check.
546 if (Ptr->getType()->getPointerAddressSpace())
549 SanitizerScope SanScope(this);
551 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
552 llvm::BasicBlock *Done = nullptr;
554 // Quickly determine whether we have a pointer to an alloca. It's possible
555 // to skip null checks, and some alignment checks, for these pointers. This
556 // can reduce compile-time significantly.
558 dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
560 bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
561 TCK == TCK_UpcastToVirtualBase;
562 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
563 !SkippedChecks.has(SanitizerKind::Null) && !PtrToAlloca) {
564 // The glvalue must not be an empty glvalue.
565 llvm::Value *IsNonNull = Builder.CreateIsNotNull(Ptr);
567 // The IR builder can constant-fold the null check if the pointer points to
570 IsNonNull == llvm::ConstantInt::getTrue(getLLVMContext());
572 // Skip the null check if the pointer is known to be non-null.
574 if (AllowNullPointers) {
575 // When performing pointer casts, it's OK if the value is null.
576 // Skip the remaining checks in that case.
577 Done = createBasicBlock("null");
578 llvm::BasicBlock *Rest = createBasicBlock("not.null");
579 Builder.CreateCondBr(IsNonNull, Rest, Done);
582 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
587 if (SanOpts.has(SanitizerKind::ObjectSize) &&
588 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
589 !Ty->isIncompleteType()) {
590 uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
592 // The glvalue must refer to a large enough storage region.
593 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
595 // FIXME: Get object address space
596 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
597 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
598 llvm::Value *Min = Builder.getFalse();
599 llvm::Value *NullIsUnknown = Builder.getFalse();
600 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
601 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
602 Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown}),
603 llvm::ConstantInt::get(IntPtrTy, Size));
604 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
607 uint64_t AlignVal = 0;
609 if (SanOpts.has(SanitizerKind::Alignment) &&
610 !SkippedChecks.has(SanitizerKind::Alignment)) {
611 AlignVal = Alignment.getQuantity();
612 if (!Ty->isIncompleteType() && !AlignVal)
613 AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
615 // The glvalue must be suitably aligned.
617 (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
619 Builder.CreateAnd(Builder.CreatePtrToInt(Ptr, IntPtrTy),
620 llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
621 llvm::Value *Aligned =
622 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
623 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
627 if (Checks.size() > 0) {
628 // Make sure we're not losing information. Alignment needs to be a power of
630 assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
631 llvm::Constant *StaticData[] = {
632 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
633 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
634 llvm::ConstantInt::get(Int8Ty, TCK)};
635 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData, Ptr);
638 // If possible, check that the vptr indicates that there is a subobject of
639 // type Ty at offset zero within this object.
641 // C++11 [basic.life]p5,6:
642 // [For storage which does not refer to an object within its lifetime]
643 // The program has undefined behavior if:
644 // -- the [pointer or glvalue] is used to access a non-static data member
645 // or call a non-static member function
646 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
647 if (SanOpts.has(SanitizerKind::Vptr) &&
648 !SkippedChecks.has(SanitizerKind::Vptr) &&
649 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
650 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
651 TCK == TCK_UpcastToVirtualBase) &&
652 RD && RD->hasDefinition() && RD->isDynamicClass()) {
653 // Compute a hash of the mangled name of the type.
655 // FIXME: This is not guaranteed to be deterministic! Move to a
656 // fingerprinting mechanism once LLVM provides one. For the time
657 // being the implementation happens to be deterministic.
658 SmallString<64> MangledName;
659 llvm::raw_svector_ostream Out(MangledName);
660 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
663 // Blacklist based on the mangled type.
664 if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
666 llvm::hash_code TypeHash = hash_value(Out.str());
668 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
669 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
670 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
671 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
672 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
673 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
675 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
676 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
678 // Look the hash up in our cache.
679 const int CacheSize = 128;
680 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
681 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
682 "__ubsan_vptr_type_cache");
683 llvm::Value *Slot = Builder.CreateAnd(Hash,
684 llvm::ConstantInt::get(IntPtrTy,
686 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
687 llvm::Value *CacheVal =
688 Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
691 // If the hash isn't in the cache, call a runtime handler to perform the
692 // hard work of checking whether the vptr is for an object of the right
693 // type. This will either fill in the cache and return, or produce a
695 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
696 llvm::Constant *StaticData[] = {
697 EmitCheckSourceLocation(Loc),
698 EmitCheckTypeDescriptor(Ty),
699 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
700 llvm::ConstantInt::get(Int8Ty, TCK)
702 llvm::Value *DynamicData[] = { Ptr, Hash };
703 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
704 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
710 Builder.CreateBr(Done);
715 /// Determine whether this expression refers to a flexible array member in a
716 /// struct. We disable array bounds checks for such members.
717 static bool isFlexibleArrayMemberExpr(const Expr *E) {
718 // For compatibility with existing code, we treat arrays of length 0 or
719 // 1 as flexible array members.
720 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
721 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
722 if (CAT->getSize().ugt(1))
724 } else if (!isa<IncompleteArrayType>(AT))
727 E = E->IgnoreParens();
729 // A flexible array member must be the last member in the class.
730 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
731 // FIXME: If the base type of the member expr is not FD->getParent(),
732 // this should not be treated as a flexible array member access.
733 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
734 RecordDecl::field_iterator FI(
735 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
736 return ++FI == FD->getParent()->field_end();
738 } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
739 return IRE->getDecl()->getNextIvar() == nullptr;
745 /// If Base is known to point to the start of an array, return the length of
746 /// that array. Return 0 if the length cannot be determined.
747 static llvm::Value *getArrayIndexingBound(
748 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
749 // For the vector indexing extension, the bound is the number of elements.
750 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
751 IndexedType = Base->getType();
752 return CGF.Builder.getInt32(VT->getNumElements());
755 Base = Base->IgnoreParens();
757 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
758 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
759 !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
760 IndexedType = CE->getSubExpr()->getType();
761 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
762 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
763 return CGF.Builder.getInt(CAT->getSize());
764 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
765 return CGF.getVLASize(VAT).first;
772 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
773 llvm::Value *Index, QualType IndexType,
775 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
776 "should not be called unless adding bounds checks");
777 SanitizerScope SanScope(this);
779 QualType IndexedType;
780 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
784 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
785 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
786 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
788 llvm::Constant *StaticData[] = {
789 EmitCheckSourceLocation(E->getExprLoc()),
790 EmitCheckTypeDescriptor(IndexedType),
791 EmitCheckTypeDescriptor(IndexType)
793 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
794 : Builder.CreateICmpULE(IndexVal, BoundVal);
795 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
796 SanitizerHandler::OutOfBounds, StaticData, Index);
800 CodeGenFunction::ComplexPairTy CodeGenFunction::
801 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
802 bool isInc, bool isPre) {
803 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
805 llvm::Value *NextVal;
806 if (isa<llvm::IntegerType>(InVal.first->getType())) {
807 uint64_t AmountVal = isInc ? 1 : -1;
808 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
810 // Add the inc/dec to the real part.
811 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
813 QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
814 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
817 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
819 // Add the inc/dec to the real part.
820 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
823 ComplexPairTy IncVal(NextVal, InVal.second);
825 // Store the updated result through the lvalue.
826 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
828 // If this is a postinc, return the value read from memory, otherwise use the
830 return isPre ? IncVal : InVal;
833 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
834 CodeGenFunction *CGF) {
835 // Bind VLAs in the cast type.
836 if (CGF && E->getType()->isVariablyModifiedType())
837 CGF->EmitVariablyModifiedType(E->getType());
839 if (CGDebugInfo *DI = getModuleDebugInfo())
840 DI->EmitExplicitCastType(E->getType());
843 //===----------------------------------------------------------------------===//
844 // LValue Expression Emission
845 //===----------------------------------------------------------------------===//
847 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
848 /// derive a more accurate bound on the alignment of the pointer.
849 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
850 AlignmentSource *Source) {
851 // We allow this with ObjC object pointers because of fragile ABIs.
852 assert(E->getType()->isPointerType() ||
853 E->getType()->isObjCObjectPointerType());
854 E = E->IgnoreParens();
857 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
858 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
859 CGM.EmitExplicitCastExprType(ECE, this);
861 switch (CE->getCastKind()) {
862 // Non-converting casts (but not C's implicit conversion from void*).
865 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
866 if (PtrTy->getPointeeType()->isVoidType())
869 AlignmentSource InnerSource;
870 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), &InnerSource);
871 if (Source) *Source = InnerSource;
873 // If this is an explicit bitcast, and the source l-value is
874 // opaque, honor the alignment of the casted-to type.
875 if (isa<ExplicitCastExpr>(CE) &&
876 InnerSource != AlignmentSource::Decl) {
877 Addr = Address(Addr.getPointer(),
878 getNaturalPointeeTypeAlignment(E->getType(), Source));
881 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
882 CE->getCastKind() == CK_BitCast) {
883 if (auto PT = E->getType()->getAs<PointerType>())
884 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
886 CodeGenFunction::CFITCK_UnrelatedCast,
890 return Builder.CreateBitCast(Addr, ConvertType(E->getType()));
894 // Array-to-pointer decay.
895 case CK_ArrayToPointerDecay:
896 return EmitArrayToPointerDecay(CE->getSubExpr(), Source);
898 // Derived-to-base conversions.
899 case CK_UncheckedDerivedToBase:
900 case CK_DerivedToBase: {
901 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), Source);
902 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
903 return GetAddressOfBaseClass(Addr, Derived,
904 CE->path_begin(), CE->path_end(),
905 ShouldNullCheckClassCastValue(CE),
909 // TODO: Is there any reason to treat base-to-derived conversions
917 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
918 if (UO->getOpcode() == UO_AddrOf) {
919 LValue LV = EmitLValue(UO->getSubExpr());
920 if (Source) *Source = LV.getAlignmentSource();
921 return LV.getAddress();
925 // TODO: conditional operators, comma.
927 // Otherwise, use the alignment of the type.
928 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), Source);
929 return Address(EmitScalarExpr(E), Align);
932 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
933 if (Ty->isVoidType())
934 return RValue::get(nullptr);
936 switch (getEvaluationKind(Ty)) {
939 ConvertType(Ty->castAs<ComplexType>()->getElementType());
940 llvm::Value *U = llvm::UndefValue::get(EltTy);
941 return RValue::getComplex(std::make_pair(U, U));
944 // If this is a use of an undefined aggregate type, the aggregate must have an
945 // identifiable address. Just because the contents of the value are undefined
946 // doesn't mean that the address can't be taken and compared.
947 case TEK_Aggregate: {
948 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
949 return RValue::getAggregate(DestPtr);
953 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
955 llvm_unreachable("bad evaluation kind");
958 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
960 ErrorUnsupported(E, Name);
961 return GetUndefRValue(E->getType());
964 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
966 ErrorUnsupported(E, Name);
967 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
968 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
972 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
973 const Expr *Base = Obj;
974 while (!isa<CXXThisExpr>(Base)) {
975 // The result of a dynamic_cast can be null.
976 if (isa<CXXDynamicCastExpr>(Base))
979 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
980 Base = CE->getSubExpr();
981 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
982 Base = PE->getSubExpr();
983 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
984 if (UO->getOpcode() == UO_Extension)
985 Base = UO->getSubExpr();
995 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
997 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
998 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1001 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1002 SanitizerSet SkippedChecks;
1003 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1004 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1006 SkippedChecks.set(SanitizerKind::Alignment, true);
1007 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1008 SkippedChecks.set(SanitizerKind::Null, true);
1010 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1011 E->getType(), LV.getAlignment(), SkippedChecks);
1016 /// EmitLValue - Emit code to compute a designator that specifies the location
1017 /// of the expression.
1019 /// This can return one of two things: a simple address or a bitfield reference.
1020 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1021 /// an LLVM pointer type.
1023 /// If this returns a bitfield reference, nothing about the pointee type of the
1024 /// LLVM value is known: For example, it may not be a pointer to an integer.
1026 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1027 /// this method guarantees that the returned pointer type will point to an LLVM
1028 /// type of the same size of the lvalue's type. If the lvalue has a variable
1029 /// length type, this is not possible.
1031 LValue CodeGenFunction::EmitLValue(const Expr *E) {
1032 ApplyDebugLocation DL(*this, E);
1033 switch (E->getStmtClass()) {
1034 default: return EmitUnsupportedLValue(E, "l-value expression");
1036 case Expr::ObjCPropertyRefExprClass:
1037 llvm_unreachable("cannot emit a property reference directly");
1039 case Expr::ObjCSelectorExprClass:
1040 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1041 case Expr::ObjCIsaExprClass:
1042 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1043 case Expr::BinaryOperatorClass:
1044 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1045 case Expr::CompoundAssignOperatorClass: {
1046 QualType Ty = E->getType();
1047 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1048 Ty = AT->getValueType();
1049 if (!Ty->isAnyComplexType())
1050 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1051 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1053 case Expr::CallExprClass:
1054 case Expr::CXXMemberCallExprClass:
1055 case Expr::CXXOperatorCallExprClass:
1056 case Expr::UserDefinedLiteralClass:
1057 return EmitCallExprLValue(cast<CallExpr>(E));
1058 case Expr::VAArgExprClass:
1059 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1060 case Expr::DeclRefExprClass:
1061 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1062 case Expr::ParenExprClass:
1063 return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1064 case Expr::GenericSelectionExprClass:
1065 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1066 case Expr::PredefinedExprClass:
1067 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1068 case Expr::StringLiteralClass:
1069 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1070 case Expr::ObjCEncodeExprClass:
1071 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1072 case Expr::PseudoObjectExprClass:
1073 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1074 case Expr::InitListExprClass:
1075 return EmitInitListLValue(cast<InitListExpr>(E));
1076 case Expr::CXXTemporaryObjectExprClass:
1077 case Expr::CXXConstructExprClass:
1078 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1079 case Expr::CXXBindTemporaryExprClass:
1080 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1081 case Expr::CXXUuidofExprClass:
1082 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1083 case Expr::LambdaExprClass:
1084 return EmitLambdaLValue(cast<LambdaExpr>(E));
1086 case Expr::ExprWithCleanupsClass: {
1087 const auto *cleanups = cast<ExprWithCleanups>(E);
1088 enterFullExpression(cleanups);
1089 RunCleanupsScope Scope(*this);
1090 LValue LV = EmitLValue(cleanups->getSubExpr());
1091 if (LV.isSimple()) {
1092 // Defend against branches out of gnu statement expressions surrounded by
1094 llvm::Value *V = LV.getPointer();
1095 Scope.ForceCleanup({&V});
1096 return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1097 getContext(), LV.getAlignmentSource(),
1100 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1101 // bitfield lvalue or some other non-simple lvalue?
1105 case Expr::CXXDefaultArgExprClass:
1106 return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1107 case Expr::CXXDefaultInitExprClass: {
1108 CXXDefaultInitExprScope Scope(*this);
1109 return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1111 case Expr::CXXTypeidExprClass:
1112 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1114 case Expr::ObjCMessageExprClass:
1115 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1116 case Expr::ObjCIvarRefExprClass:
1117 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1118 case Expr::StmtExprClass:
1119 return EmitStmtExprLValue(cast<StmtExpr>(E));
1120 case Expr::UnaryOperatorClass:
1121 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1122 case Expr::ArraySubscriptExprClass:
1123 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1124 case Expr::OMPArraySectionExprClass:
1125 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1126 case Expr::ExtVectorElementExprClass:
1127 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1128 case Expr::MemberExprClass:
1129 return EmitMemberExpr(cast<MemberExpr>(E));
1130 case Expr::CompoundLiteralExprClass:
1131 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1132 case Expr::ConditionalOperatorClass:
1133 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1134 case Expr::BinaryConditionalOperatorClass:
1135 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1136 case Expr::ChooseExprClass:
1137 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1138 case Expr::OpaqueValueExprClass:
1139 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1140 case Expr::SubstNonTypeTemplateParmExprClass:
1141 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1142 case Expr::ImplicitCastExprClass:
1143 case Expr::CStyleCastExprClass:
1144 case Expr::CXXFunctionalCastExprClass:
1145 case Expr::CXXStaticCastExprClass:
1146 case Expr::CXXDynamicCastExprClass:
1147 case Expr::CXXReinterpretCastExprClass:
1148 case Expr::CXXConstCastExprClass:
1149 case Expr::ObjCBridgedCastExprClass:
1150 return EmitCastLValue(cast<CastExpr>(E));
1152 case Expr::MaterializeTemporaryExprClass:
1153 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1157 /// Given an object of the given canonical type, can we safely copy a
1158 /// value out of it based on its initializer?
1159 static bool isConstantEmittableObjectType(QualType type) {
1160 assert(type.isCanonical());
1161 assert(!type->isReferenceType());
1163 // Must be const-qualified but non-volatile.
1164 Qualifiers qs = type.getLocalQualifiers();
1165 if (!qs.hasConst() || qs.hasVolatile()) return false;
1167 // Otherwise, all object types satisfy this except C++ classes with
1168 // mutable subobjects or non-trivial copy/destroy behavior.
1169 if (const auto *RT = dyn_cast<RecordType>(type))
1170 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1171 if (RD->hasMutableFields() || !RD->isTrivial())
1177 /// Can we constant-emit a load of a reference to a variable of the
1178 /// given type? This is different from predicates like
1179 /// Decl::isUsableInConstantExpressions because we do want it to apply
1180 /// in situations that don't necessarily satisfy the language's rules
1181 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1182 /// to do this with const float variables even if those variables
1183 /// aren't marked 'constexpr'.
1184 enum ConstantEmissionKind {
1186 CEK_AsReferenceOnly,
1187 CEK_AsValueOrReference,
1190 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1191 type = type.getCanonicalType();
1192 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1193 if (isConstantEmittableObjectType(ref->getPointeeType()))
1194 return CEK_AsValueOrReference;
1195 return CEK_AsReferenceOnly;
1197 if (isConstantEmittableObjectType(type))
1198 return CEK_AsValueOnly;
1202 /// Try to emit a reference to the given value without producing it as
1203 /// an l-value. This is actually more than an optimization: we can't
1204 /// produce an l-value for variables that we never actually captured
1205 /// in a block or lambda, which means const int variables or constexpr
1206 /// literals or similar.
1207 CodeGenFunction::ConstantEmission
1208 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1209 ValueDecl *value = refExpr->getDecl();
1211 // The value needs to be an enum constant or a constant variable.
1212 ConstantEmissionKind CEK;
1213 if (isa<ParmVarDecl>(value)) {
1215 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1216 CEK = checkVarTypeForConstantEmission(var->getType());
1217 } else if (isa<EnumConstantDecl>(value)) {
1218 CEK = CEK_AsValueOnly;
1222 if (CEK == CEK_None) return ConstantEmission();
1224 Expr::EvalResult result;
1225 bool resultIsReference;
1226 QualType resultType;
1228 // It's best to evaluate all the way as an r-value if that's permitted.
1229 if (CEK != CEK_AsReferenceOnly &&
1230 refExpr->EvaluateAsRValue(result, getContext())) {
1231 resultIsReference = false;
1232 resultType = refExpr->getType();
1234 // Otherwise, try to evaluate as an l-value.
1235 } else if (CEK != CEK_AsValueOnly &&
1236 refExpr->EvaluateAsLValue(result, getContext())) {
1237 resultIsReference = true;
1238 resultType = value->getType();
1242 return ConstantEmission();
1245 // In any case, if the initializer has side-effects, abandon ship.
1246 if (result.HasSideEffects)
1247 return ConstantEmission();
1249 // Emit as a constant.
1250 llvm::Constant *C = CGM.EmitConstantValue(result.Val, resultType, this);
1252 // Make sure we emit a debug reference to the global variable.
1253 // This should probably fire even for
1254 if (isa<VarDecl>(value)) {
1255 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1256 EmitDeclRefExprDbgValue(refExpr, result.Val);
1258 assert(isa<EnumConstantDecl>(value));
1259 EmitDeclRefExprDbgValue(refExpr, result.Val);
1262 // If we emitted a reference constant, we need to dereference that.
1263 if (resultIsReference)
1264 return ConstantEmission::forReference(C);
1266 return ConstantEmission::forValue(C);
1269 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1270 SourceLocation Loc) {
1271 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1272 lvalue.getType(), Loc, lvalue.getAlignmentSource(),
1273 lvalue.getTBAAInfo(),
1274 lvalue.getTBAABaseType(), lvalue.getTBAAOffset(),
1275 lvalue.isNontemporal());
1278 static bool hasBooleanRepresentation(QualType Ty) {
1279 if (Ty->isBooleanType())
1282 if (const EnumType *ET = Ty->getAs<EnumType>())
1283 return ET->getDecl()->getIntegerType()->isBooleanType();
1285 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1286 return hasBooleanRepresentation(AT->getValueType());
1291 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1292 llvm::APInt &Min, llvm::APInt &End,
1293 bool StrictEnums, bool IsBool) {
1294 const EnumType *ET = Ty->getAs<EnumType>();
1295 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1296 ET && !ET->getDecl()->isFixed();
1297 if (!IsBool && !IsRegularCPlusPlusEnum)
1301 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1302 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1304 const EnumDecl *ED = ET->getDecl();
1305 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1306 unsigned Bitwidth = LTy->getScalarSizeInBits();
1307 unsigned NumNegativeBits = ED->getNumNegativeBits();
1308 unsigned NumPositiveBits = ED->getNumPositiveBits();
1310 if (NumNegativeBits) {
1311 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1312 assert(NumBits <= Bitwidth);
1313 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1316 assert(NumPositiveBits <= Bitwidth);
1317 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1318 Min = llvm::APInt(Bitwidth, 0);
1324 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1325 llvm::APInt Min, End;
1326 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1327 hasBooleanRepresentation(Ty)))
1330 llvm::MDBuilder MDHelper(getLLVMContext());
1331 return MDHelper.createRange(Min, End);
1334 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1335 SourceLocation Loc) {
1336 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1337 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1338 if (!HasBoolCheck && !HasEnumCheck)
1341 bool IsBool = hasBooleanRepresentation(Ty) ||
1342 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1343 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1344 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1345 if (!NeedsBoolCheck && !NeedsEnumCheck)
1348 // Single-bit booleans don't need to be checked. Special-case this to avoid
1349 // a bit width mismatch when handling bitfield values. This is handled by
1350 // EmitFromMemory for the non-bitfield case.
1352 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1355 llvm::APInt Min, End;
1356 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1359 SanitizerScope SanScope(this);
1363 Check = Builder.CreateICmpULE(
1364 Value, llvm::ConstantInt::get(getLLVMContext(), End));
1366 llvm::Value *Upper = Builder.CreateICmpSLE(
1367 Value, llvm::ConstantInt::get(getLLVMContext(), End));
1368 llvm::Value *Lower = Builder.CreateICmpSGE(
1369 Value, llvm::ConstantInt::get(getLLVMContext(), Min));
1370 Check = Builder.CreateAnd(Upper, Lower);
1372 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1373 EmitCheckTypeDescriptor(Ty)};
1374 SanitizerMask Kind =
1375 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1376 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1377 StaticArgs, EmitCheckValue(Value));
1381 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1384 AlignmentSource AlignSource,
1385 llvm::MDNode *TBAAInfo,
1386 QualType TBAABaseType,
1387 uint64_t TBAAOffset,
1388 bool isNontemporal) {
1389 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1390 // For better performance, handle vector loads differently.
1391 if (Ty->isVectorType()) {
1392 const llvm::Type *EltTy = Addr.getElementType();
1394 const auto *VTy = cast<llvm::VectorType>(EltTy);
1396 // Handle vectors of size 3 like size 4 for better performance.
1397 if (VTy->getNumElements() == 3) {
1399 // Bitcast to vec4 type.
1400 llvm::VectorType *vec4Ty =
1401 llvm::VectorType::get(VTy->getElementType(), 4);
1402 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1404 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1406 // Shuffle vector to get vec3.
1407 V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1408 {0, 1, 2}, "extractVec");
1409 return EmitFromMemory(V, Ty);
1414 // Atomic operations have to be done on integral types.
1415 LValue AtomicLValue =
1416 LValue::MakeAddr(Addr, Ty, getContext(), AlignSource, TBAAInfo);
1417 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1418 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1421 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1422 if (isNontemporal) {
1423 llvm::MDNode *Node = llvm::MDNode::get(
1424 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1425 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1428 llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
1431 CGM.DecorateInstructionWithTBAA(Load, TBAAPath,
1432 false /*ConvertTypeToTag*/);
1435 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1436 // In order to prevent the optimizer from throwing away the check, don't
1437 // attach range metadata to the load.
1438 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1439 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1440 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1442 return EmitFromMemory(Load, Ty);
1445 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1446 // Bool has a different representation in memory than in registers.
1447 if (hasBooleanRepresentation(Ty)) {
1448 // This should really always be an i1, but sometimes it's already
1449 // an i8, and it's awkward to track those cases down.
1450 if (Value->getType()->isIntegerTy(1))
1451 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1452 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1453 "wrong value rep of bool");
1459 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1460 // Bool has a different representation in memory than in registers.
1461 if (hasBooleanRepresentation(Ty)) {
1462 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1463 "wrong value rep of bool");
1464 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1470 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1471 bool Volatile, QualType Ty,
1472 AlignmentSource AlignSource,
1473 llvm::MDNode *TBAAInfo,
1474 bool isInit, QualType TBAABaseType,
1475 uint64_t TBAAOffset,
1476 bool isNontemporal) {
1478 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1479 // Handle vectors differently to get better performance.
1480 if (Ty->isVectorType()) {
1481 llvm::Type *SrcTy = Value->getType();
1482 auto *VecTy = cast<llvm::VectorType>(SrcTy);
1483 // Handle vec3 special.
1484 if (VecTy->getNumElements() == 3) {
1485 // Our source is a vec3, do a shuffle vector to make it a vec4.
1486 llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1487 Builder.getInt32(2),
1488 llvm::UndefValue::get(Builder.getInt32Ty())};
1489 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1490 Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1491 MaskV, "extractVec");
1492 SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1494 if (Addr.getElementType() != SrcTy) {
1495 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1500 Value = EmitToMemory(Value, Ty);
1502 LValue AtomicLValue =
1503 LValue::MakeAddr(Addr, Ty, getContext(), AlignSource, TBAAInfo);
1504 if (Ty->isAtomicType() ||
1505 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1506 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1510 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1511 if (isNontemporal) {
1512 llvm::MDNode *Node =
1513 llvm::MDNode::get(Store->getContext(),
1514 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1515 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1518 llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
1521 CGM.DecorateInstructionWithTBAA(Store, TBAAPath,
1522 false /*ConvertTypeToTag*/);
1526 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1528 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1529 lvalue.getType(), lvalue.getAlignmentSource(),
1530 lvalue.getTBAAInfo(), isInit, lvalue.getTBAABaseType(),
1531 lvalue.getTBAAOffset(), lvalue.isNontemporal());
1534 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1535 /// method emits the address of the lvalue, then loads the result as an rvalue,
1536 /// returning the rvalue.
1537 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1538 if (LV.isObjCWeak()) {
1539 // load of a __weak object.
1540 Address AddrWeakObj = LV.getAddress();
1541 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1544 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1545 // In MRC mode, we do a load+autorelease.
1546 if (!getLangOpts().ObjCAutoRefCount) {
1547 return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1550 // In ARC mode, we load retained and then consume the value.
1551 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
1552 Object = EmitObjCConsumeObject(LV.getType(), Object);
1553 return RValue::get(Object);
1556 if (LV.isSimple()) {
1557 assert(!LV.getType()->isFunctionType());
1559 // Everything needs a load.
1560 return RValue::get(EmitLoadOfScalar(LV, Loc));
1563 if (LV.isVectorElt()) {
1564 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1565 LV.isVolatileQualified());
1566 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1570 // If this is a reference to a subset of the elements of a vector, either
1571 // shuffle the input or extract/insert them as appropriate.
1572 if (LV.isExtVectorElt())
1573 return EmitLoadOfExtVectorElementLValue(LV);
1575 // Global Register variables always invoke intrinsics
1576 if (LV.isGlobalReg())
1577 return EmitLoadOfGlobalRegLValue(LV);
1579 assert(LV.isBitField() && "Unknown LValue type!");
1580 return EmitLoadOfBitfieldLValue(LV, Loc);
1583 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
1584 SourceLocation Loc) {
1585 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1587 // Get the output type.
1588 llvm::Type *ResLTy = ConvertType(LV.getType());
1590 Address Ptr = LV.getBitFieldAddress();
1591 llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1593 if (Info.IsSigned) {
1594 assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1595 unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1597 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1598 if (Info.Offset + HighBits)
1599 Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1602 Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1603 if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1604 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1608 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1609 EmitScalarRangeCheck(Val, LV.getType(), Loc);
1610 return RValue::get(Val);
1613 // If this is a reference to a subset of the elements of a vector, create an
1614 // appropriate shufflevector.
1615 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1616 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1617 LV.isVolatileQualified());
1619 const llvm::Constant *Elts = LV.getExtVectorElts();
1621 // If the result of the expression is a non-vector type, we must be extracting
1622 // a single element. Just codegen as an extractelement.
1623 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1625 unsigned InIdx = getAccessedFieldNo(0, Elts);
1626 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1627 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1630 // Always use shuffle vector to try to retain the original program structure
1631 unsigned NumResultElts = ExprVT->getNumElements();
1633 SmallVector<llvm::Constant*, 4> Mask;
1634 for (unsigned i = 0; i != NumResultElts; ++i)
1635 Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1637 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1638 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1640 return RValue::get(Vec);
1643 /// @brief Generates lvalue for partial ext_vector access.
1644 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
1645 Address VectorAddress = LV.getExtVectorAddress();
1646 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1647 QualType EQT = ExprVT->getElementType();
1648 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1650 Address CastToPointerElement =
1651 Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1652 "conv.ptr.element");
1654 const llvm::Constant *Elts = LV.getExtVectorElts();
1655 unsigned ix = getAccessedFieldNo(0, Elts);
1657 Address VectorBasePtrPlusIx =
1658 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1659 getContext().getTypeSizeInChars(EQT),
1662 return VectorBasePtrPlusIx;
1665 /// @brief Load of global gamed gegisters are always calls to intrinsics.
1666 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
1667 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1668 "Bad type for register variable");
1669 llvm::MDNode *RegName = cast<llvm::MDNode>(
1670 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1672 // We accept integer and pointer types only
1673 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1674 llvm::Type *Ty = OrigTy;
1675 if (OrigTy->isPointerTy())
1676 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1677 llvm::Type *Types[] = { Ty };
1679 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1680 llvm::Value *Call = Builder.CreateCall(
1681 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1682 if (OrigTy->isPointerTy())
1683 Call = Builder.CreateIntToPtr(Call, OrigTy);
1684 return RValue::get(Call);
1688 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1689 /// lvalue, where both are guaranteed to the have the same type, and that type
1691 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
1693 if (!Dst.isSimple()) {
1694 if (Dst.isVectorElt()) {
1695 // Read/modify/write the vector, inserting the new element.
1696 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
1697 Dst.isVolatileQualified());
1698 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1699 Dst.getVectorIdx(), "vecins");
1700 Builder.CreateStore(Vec, Dst.getVectorAddress(),
1701 Dst.isVolatileQualified());
1705 // If this is an update of extended vector elements, insert them as
1707 if (Dst.isExtVectorElt())
1708 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
1710 if (Dst.isGlobalReg())
1711 return EmitStoreThroughGlobalRegLValue(Src, Dst);
1713 assert(Dst.isBitField() && "Unknown LValue type");
1714 return EmitStoreThroughBitfieldLValue(Src, Dst);
1717 // There's special magic for assigning into an ARC-qualified l-value.
1718 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1720 case Qualifiers::OCL_None:
1721 llvm_unreachable("present but none");
1723 case Qualifiers::OCL_ExplicitNone:
1727 case Qualifiers::OCL_Strong:
1729 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1732 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1735 case Qualifiers::OCL_Weak:
1737 // Initialize and then skip the primitive store.
1738 EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1740 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1743 case Qualifiers::OCL_Autoreleasing:
1744 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
1745 Src.getScalarVal()));
1746 // fall into the normal path
1751 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1752 // load of a __weak object.
1753 Address LvalueDst = Dst.getAddress();
1754 llvm::Value *src = Src.getScalarVal();
1755 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1759 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1760 // load of a __strong object.
1761 Address LvalueDst = Dst.getAddress();
1762 llvm::Value *src = Src.getScalarVal();
1763 if (Dst.isObjCIvar()) {
1764 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1765 llvm::Type *ResultType = IntPtrTy;
1766 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
1767 llvm::Value *RHS = dst.getPointer();
1768 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1770 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1771 "sub.ptr.lhs.cast");
1772 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
1773 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1775 } else if (Dst.isGlobalObjCRef()) {
1776 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1777 Dst.isThreadLocalRef());
1780 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1784 assert(Src.isScalar() && "Can't emit an agg store with this method");
1785 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
1788 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
1789 llvm::Value **Result) {
1790 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1791 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1792 Address Ptr = Dst.getBitFieldAddress();
1794 // Get the source value, truncated to the width of the bit-field.
1795 llvm::Value *SrcVal = Src.getScalarVal();
1797 // Cast the source to the storage type and shift it into place.
1798 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
1799 /*IsSigned=*/false);
1800 llvm::Value *MaskedVal = SrcVal;
1802 // See if there are other bits in the bitfield's storage we'll need to load
1803 // and mask together with source before storing.
1804 if (Info.StorageSize != Info.Size) {
1805 assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
1807 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
1809 // Mask the source value as needed.
1810 if (!hasBooleanRepresentation(Dst.getType()))
1811 SrcVal = Builder.CreateAnd(SrcVal,
1812 llvm::APInt::getLowBitsSet(Info.StorageSize,
1817 SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
1819 // Mask out the original value.
1820 Val = Builder.CreateAnd(Val,
1821 ~llvm::APInt::getBitsSet(Info.StorageSize,
1823 Info.Offset + Info.Size),
1826 // Or together the unchanged values and the source value.
1827 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
1829 assert(Info.Offset == 0);
1832 // Write the new value back out.
1833 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
1835 // Return the new value of the bit-field, if requested.
1837 llvm::Value *ResultVal = MaskedVal;
1839 // Sign extend the value if needed.
1840 if (Info.IsSigned) {
1841 assert(Info.Size <= Info.StorageSize);
1842 unsigned HighBits = Info.StorageSize - Info.Size;
1844 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
1845 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
1849 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
1851 *Result = EmitFromMemory(ResultVal, Dst.getType());
1855 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
1857 // This access turns into a read/modify/write of the vector. Load the input
1859 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
1860 Dst.isVolatileQualified());
1861 const llvm::Constant *Elts = Dst.getExtVectorElts();
1863 llvm::Value *SrcVal = Src.getScalarVal();
1865 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
1866 unsigned NumSrcElts = VTy->getNumElements();
1867 unsigned NumDstElts = Vec->getType()->getVectorNumElements();
1868 if (NumDstElts == NumSrcElts) {
1869 // Use shuffle vector is the src and destination are the same number of
1870 // elements and restore the vector mask since it is on the side it will be
1872 SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1873 for (unsigned i = 0; i != NumSrcElts; ++i)
1874 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
1876 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1877 Vec = Builder.CreateShuffleVector(SrcVal,
1878 llvm::UndefValue::get(Vec->getType()),
1880 } else if (NumDstElts > NumSrcElts) {
1881 // Extended the source vector to the same length and then shuffle it
1882 // into the destination.
1883 // FIXME: since we're shuffling with undef, can we just use the indices
1884 // into that? This could be simpler.
1885 SmallVector<llvm::Constant*, 4> ExtMask;
1886 for (unsigned i = 0; i != NumSrcElts; ++i)
1887 ExtMask.push_back(Builder.getInt32(i));
1888 ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
1889 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
1890 llvm::Value *ExtSrcVal =
1891 Builder.CreateShuffleVector(SrcVal,
1892 llvm::UndefValue::get(SrcVal->getType()),
1895 SmallVector<llvm::Constant*, 4> Mask;
1896 for (unsigned i = 0; i != NumDstElts; ++i)
1897 Mask.push_back(Builder.getInt32(i));
1899 // When the vector size is odd and .odd or .hi is used, the last element
1900 // of the Elts constant array will be one past the size of the vector.
1901 // Ignore the last element here, if it is greater than the mask size.
1902 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
1905 // modify when what gets shuffled in
1906 for (unsigned i = 0; i != NumSrcElts; ++i)
1907 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
1908 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1909 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
1911 // We should never shorten the vector
1912 llvm_unreachable("unexpected shorten vector length");
1915 // If the Src is a scalar (not a vector) it must be updating one element.
1916 unsigned InIdx = getAccessedFieldNo(0, Elts);
1917 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1918 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
1921 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
1922 Dst.isVolatileQualified());
1925 /// @brief Store of global named registers are always calls to intrinsics.
1926 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
1927 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
1928 "Bad type for register variable");
1929 llvm::MDNode *RegName = cast<llvm::MDNode>(
1930 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
1931 assert(RegName && "Register LValue is not metadata");
1933 // We accept integer and pointer types only
1934 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
1935 llvm::Type *Ty = OrigTy;
1936 if (OrigTy->isPointerTy())
1937 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1938 llvm::Type *Types[] = { Ty };
1940 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
1941 llvm::Value *Value = Src.getScalarVal();
1942 if (OrigTy->isPointerTy())
1943 Value = Builder.CreatePtrToInt(Value, Ty);
1945 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
1948 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
1949 // generating write-barries API. It is currently a global, ivar,
1951 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1953 bool IsMemberAccess=false) {
1954 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
1957 if (isa<ObjCIvarRefExpr>(E)) {
1958 QualType ExpTy = E->getType();
1959 if (IsMemberAccess && ExpTy->isPointerType()) {
1960 // If ivar is a structure pointer, assigning to field of
1961 // this struct follows gcc's behavior and makes it a non-ivar
1962 // writer-barrier conservatively.
1963 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1964 if (ExpTy->isRecordType()) {
1965 LV.setObjCIvar(false);
1969 LV.setObjCIvar(true);
1970 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
1971 LV.setBaseIvarExp(Exp->getBase());
1972 LV.setObjCArray(E->getType()->isArrayType());
1976 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
1977 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1978 if (VD->hasGlobalStorage()) {
1979 LV.setGlobalObjCRef(true);
1980 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
1983 LV.setObjCArray(E->getType()->isArrayType());
1987 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
1988 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1992 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
1993 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1994 if (LV.isObjCIvar()) {
1995 // If cast is to a structure pointer, follow gcc's behavior and make it
1996 // a non-ivar write-barrier.
1997 QualType ExpTy = E->getType();
1998 if (ExpTy->isPointerType())
1999 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2000 if (ExpTy->isRecordType())
2001 LV.setObjCIvar(false);
2006 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2007 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2011 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2012 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2016 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2017 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2021 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2022 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2026 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2027 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2028 if (LV.isObjCIvar() && !LV.isObjCArray())
2029 // Using array syntax to assigning to what an ivar points to is not
2030 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2031 LV.setObjCIvar(false);
2032 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2033 // Using array syntax to assigning to what global points to is not
2034 // same as assigning to the global itself. {id *G;} G[i] = 0;
2035 LV.setGlobalObjCRef(false);
2039 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2040 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2041 // We don't know if member is an 'ivar', but this flag is looked at
2042 // only in the context of LV.isObjCIvar().
2043 LV.setObjCArray(E->getType()->isArrayType());
2048 static llvm::Value *
2049 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
2050 llvm::Value *V, llvm::Type *IRType,
2051 StringRef Name = StringRef()) {
2052 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2053 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2056 static LValue EmitThreadPrivateVarDeclLValue(
2057 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2058 llvm::Type *RealVarTy, SourceLocation Loc) {
2059 Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2060 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2061 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2064 Address CodeGenFunction::EmitLoadOfReference(Address Addr,
2065 const ReferenceType *RefTy,
2066 AlignmentSource *Source) {
2067 llvm::Value *Ptr = Builder.CreateLoad(Addr);
2068 return Address(Ptr, getNaturalTypeAlignment(RefTy->getPointeeType(),
2069 Source, /*forPointee*/ true));
2073 LValue CodeGenFunction::EmitLoadOfReferenceLValue(Address RefAddr,
2074 const ReferenceType *RefTy) {
2075 AlignmentSource Source;
2076 Address Addr = EmitLoadOfReference(RefAddr, RefTy, &Source);
2077 return MakeAddrLValue(Addr, RefTy->getPointeeType(), Source);
2080 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2081 const PointerType *PtrTy,
2082 AlignmentSource *Source) {
2083 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2084 return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(), Source,
2085 /*forPointeeType=*/true));
2088 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2089 const PointerType *PtrTy) {
2090 AlignmentSource Source;
2091 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &Source);
2092 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), Source);
2095 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2096 const Expr *E, const VarDecl *VD) {
2097 QualType T = E->getType();
2099 // If it's thread_local, emit a call to its wrapper function instead.
2100 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2101 CGF.CGM.getCXXABI().usesThreadWrapperFunction())
2102 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2104 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2105 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2106 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2107 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2108 Address Addr(V, Alignment);
2110 // Emit reference to the private copy of the variable if it is an OpenMP
2111 // threadprivate variable.
2112 if (CGF.getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>())
2113 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2115 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2116 LV = CGF.EmitLoadOfReferenceLValue(Addr, RefTy);
2118 LV = CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2120 setObjCGCLValueClass(CGF.getContext(), E, LV);
2124 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2125 const FunctionDecl *FD) {
2126 if (FD->hasAttr<WeakRefAttr>()) {
2127 ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2128 return aliasee.getPointer();
2131 llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2132 if (!FD->hasPrototype()) {
2133 if (const FunctionProtoType *Proto =
2134 FD->getType()->getAs<FunctionProtoType>()) {
2135 // Ugly case: for a K&R-style definition, the type of the definition
2136 // isn't the same as the type of a use. Correct for this with a
2138 QualType NoProtoType =
2139 CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2140 NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2141 V = llvm::ConstantExpr::getBitCast(V,
2142 CGM.getTypes().ConvertType(NoProtoType));
2148 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
2149 const Expr *E, const FunctionDecl *FD) {
2150 llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2151 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2152 return CGF.MakeAddrLValue(V, E->getType(), Alignment, AlignmentSource::Decl);
2155 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2156 llvm::Value *ThisValue) {
2157 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2158 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2159 return CGF.EmitLValueForField(LV, FD);
2162 /// Named Registers are named metadata pointing to the register name
2163 /// which will be read from/written to as an argument to the intrinsic
2164 /// @llvm.read/write_register.
2165 /// So far, only the name is being passed down, but other options such as
2166 /// register type, allocation type or even optimization options could be
2167 /// passed down via the metadata node.
2168 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2169 SmallString<64> Name("llvm.named.register.");
2170 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2171 assert(Asm->getLabel().size() < 64-Name.size() &&
2172 "Register name too big");
2173 Name.append(Asm->getLabel());
2174 llvm::NamedMDNode *M =
2175 CGM.getModule().getOrInsertNamedMetadata(Name);
2176 if (M->getNumOperands() == 0) {
2177 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2179 llvm::Metadata *Ops[] = {Str};
2180 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2183 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2186 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2187 return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2190 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2191 const NamedDecl *ND = E->getDecl();
2192 QualType T = E->getType();
2194 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2195 // Global Named registers access via intrinsics only
2196 if (VD->getStorageClass() == SC_Register &&
2197 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2198 return EmitGlobalNamedRegister(VD, CGM);
2200 // A DeclRefExpr for a reference initialized by a constant expression can
2201 // appear without being odr-used. Directly emit the constant initializer.
2202 const Expr *Init = VD->getAnyInitializer(VD);
2203 if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2204 VD->isUsableInConstantExpressions(getContext()) &&
2205 VD->checkInitIsICE() &&
2206 // Do not emit if it is private OpenMP variable.
2207 !(E->refersToEnclosingVariableOrCapture() && CapturedStmtInfo &&
2208 LocalDeclMap.count(VD))) {
2209 llvm::Constant *Val =
2210 CGM.EmitConstantValue(*VD->evaluateValue(), VD->getType(), this);
2211 assert(Val && "failed to emit reference constant expression");
2212 // FIXME: Eventually we will want to emit vector element references.
2214 // Should we be using the alignment of the constant pointer we emitted?
2215 CharUnits Alignment = getNaturalTypeAlignment(E->getType(), nullptr,
2218 return MakeAddrLValue(Address(Val, Alignment), T, AlignmentSource::Decl);
2221 // Check for captured variables.
2222 if (E->refersToEnclosingVariableOrCapture()) {
2223 if (auto *FD = LambdaCaptureFields.lookup(VD))
2224 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2225 else if (CapturedStmtInfo) {
2226 auto I = LocalDeclMap.find(VD);
2227 if (I != LocalDeclMap.end()) {
2228 if (auto RefTy = VD->getType()->getAs<ReferenceType>())
2229 return EmitLoadOfReferenceLValue(I->second, RefTy);
2230 return MakeAddrLValue(I->second, T);
2233 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2234 CapturedStmtInfo->getContextValue());
2235 return MakeAddrLValue(
2236 Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2237 CapLVal.getType(), AlignmentSource::Decl);
2240 assert(isa<BlockDecl>(CurCodeDecl));
2241 Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
2242 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2246 // FIXME: We should be able to assert this for FunctionDecls as well!
2247 // FIXME: We should be able to assert this for all DeclRefExprs, not just
2248 // those with a valid source location.
2249 assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2250 !E->getLocation().isValid()) &&
2251 "Should not use decl without marking it used!");
2253 if (ND->hasAttr<WeakRefAttr>()) {
2254 const auto *VD = cast<ValueDecl>(ND);
2255 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2256 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2259 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2260 // Check if this is a global variable.
2261 if (VD->hasLinkage() || VD->isStaticDataMember())
2262 return EmitGlobalVarDeclLValue(*this, E, VD);
2264 Address addr = Address::invalid();
2266 // The variable should generally be present in the local decl map.
2267 auto iter = LocalDeclMap.find(VD);
2268 if (iter != LocalDeclMap.end()) {
2269 addr = iter->second;
2271 // Otherwise, it might be static local we haven't emitted yet for
2272 // some reason; most likely, because it's in an outer function.
2273 } else if (VD->isStaticLocal()) {
2274 addr = Address(CGM.getOrCreateStaticVarDecl(
2275 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2276 getContext().getDeclAlign(VD));
2278 // No other cases for now.
2280 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2284 // Check for OpenMP threadprivate variables.
2285 if (getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2286 return EmitThreadPrivateVarDeclLValue(
2287 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2291 // Drill into block byref variables.
2292 bool isBlockByref = VD->hasAttr<BlocksAttr>();
2294 addr = emitBlockByrefAddress(addr, VD);
2297 // Drill into reference types.
2299 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2300 LV = EmitLoadOfReferenceLValue(addr, RefTy);
2302 LV = MakeAddrLValue(addr, T, AlignmentSource::Decl);
2305 bool isLocalStorage = VD->hasLocalStorage();
2307 bool NonGCable = isLocalStorage &&
2308 !VD->getType()->isReferenceType() &&
2311 LV.getQuals().removeObjCGCAttr();
2315 bool isImpreciseLifetime =
2316 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2317 if (isImpreciseLifetime)
2318 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2319 setObjCGCLValueClass(getContext(), E, LV);
2323 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2324 return EmitFunctionDeclLValue(*this, E, FD);
2326 // FIXME: While we're emitting a binding from an enclosing scope, all other
2327 // DeclRefExprs we see should be implicitly treated as if they also refer to
2328 // an enclosing scope.
2329 if (const auto *BD = dyn_cast<BindingDecl>(ND))
2330 return EmitLValue(BD->getBinding());
2332 llvm_unreachable("Unhandled DeclRefExpr");
2335 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2336 // __extension__ doesn't affect lvalue-ness.
2337 if (E->getOpcode() == UO_Extension)
2338 return EmitLValue(E->getSubExpr());
2340 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2341 switch (E->getOpcode()) {
2342 default: llvm_unreachable("Unknown unary operator lvalue!");
2344 QualType T = E->getSubExpr()->getType()->getPointeeType();
2345 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2347 AlignmentSource AlignSource;
2348 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &AlignSource);
2349 LValue LV = MakeAddrLValue(Addr, T, AlignSource);
2350 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2352 // We should not generate __weak write barrier on indirect reference
2353 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2354 // But, we continue to generate __strong write barrier on indirect write
2355 // into a pointer to object.
2356 if (getLangOpts().ObjC1 &&
2357 getLangOpts().getGC() != LangOptions::NonGC &&
2359 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2364 LValue LV = EmitLValue(E->getSubExpr());
2365 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2367 // __real is valid on scalars. This is a faster way of testing that.
2368 // __imag can only produce an rvalue on scalars.
2369 if (E->getOpcode() == UO_Real &&
2370 !LV.getAddress().getElementType()->isStructTy()) {
2371 assert(E->getSubExpr()->getType()->isArithmeticType());
2375 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2378 (E->getOpcode() == UO_Real
2379 ? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
2380 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
2381 LValue ElemLV = MakeAddrLValue(Component, T, LV.getAlignmentSource());
2382 ElemLV.getQuals().addQualifiers(LV.getQuals());
2387 LValue LV = EmitLValue(E->getSubExpr());
2388 bool isInc = E->getOpcode() == UO_PreInc;
2390 if (E->getType()->isAnyComplexType())
2391 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2393 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2399 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2400 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2401 E->getType(), AlignmentSource::Decl);
2404 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2405 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2406 E->getType(), AlignmentSource::Decl);
2409 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2410 auto SL = E->getFunctionName();
2411 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2412 StringRef FnName = CurFn->getName();
2413 if (FnName.startswith("\01"))
2414 FnName = FnName.substr(1);
2415 StringRef NameItems[] = {
2416 PredefinedExpr::getIdentTypeName(E->getIdentType()), FnName};
2417 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2418 if (auto *BD = dyn_cast<BlockDecl>(CurCodeDecl)) {
2419 std::string Name = SL->getString();
2420 if (!Name.empty()) {
2421 unsigned Discriminator =
2422 CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2424 Name += "_" + Twine(Discriminator + 1).str();
2425 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2426 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2428 auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2429 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2432 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2433 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2436 /// Emit a type description suitable for use by a runtime sanitizer library. The
2437 /// format of a type descriptor is
2440 /// { i16 TypeKind, i16 TypeInfo }
2443 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2444 /// integer, 1 for a floating point value, and -1 for anything else.
2445 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2446 // Only emit each type's descriptor once.
2447 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2450 uint16_t TypeKind = -1;
2451 uint16_t TypeInfo = 0;
2453 if (T->isIntegerType()) {
2455 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2456 (T->isSignedIntegerType() ? 1 : 0);
2457 } else if (T->isFloatingType()) {
2459 TypeInfo = getContext().getTypeSize(T);
2462 // Format the type name as if for a diagnostic, including quotes and
2463 // optionally an 'aka'.
2464 SmallString<32> Buffer;
2465 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
2466 (intptr_t)T.getAsOpaquePtr(),
2467 StringRef(), StringRef(), None, Buffer,
2470 llvm::Constant *Components[] = {
2471 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2472 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2474 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2476 auto *GV = new llvm::GlobalVariable(
2477 CGM.getModule(), Descriptor->getType(),
2478 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2479 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2480 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
2482 // Remember the descriptor for this type.
2483 CGM.setTypeDescriptorInMap(T, GV);
2488 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
2489 llvm::Type *TargetTy = IntPtrTy;
2491 // Floating-point types which fit into intptr_t are bitcast to integers
2492 // and then passed directly (after zero-extension, if necessary).
2493 if (V->getType()->isFloatingPointTy()) {
2494 unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2495 if (Bits <= TargetTy->getIntegerBitWidth())
2496 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2500 // Integers which fit in intptr_t are zero-extended and passed directly.
2501 if (V->getType()->isIntegerTy() &&
2502 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2503 return Builder.CreateZExt(V, TargetTy);
2505 // Pointers are passed directly, everything else is passed by address.
2506 if (!V->getType()->isPointerTy()) {
2507 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2508 Builder.CreateStore(V, Ptr);
2509 V = Ptr.getPointer();
2511 return Builder.CreatePtrToInt(V, TargetTy);
2514 /// \brief Emit a representation of a SourceLocation for passing to a handler
2515 /// in a sanitizer runtime library. The format for this data is:
2517 /// struct SourceLocation {
2518 /// const char *Filename;
2519 /// int32_t Line, Column;
2522 /// For an invalid SourceLocation, the Filename pointer is null.
2523 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
2524 llvm::Constant *Filename;
2527 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
2528 if (PLoc.isValid()) {
2529 StringRef FilenameString = PLoc.getFilename();
2531 int PathComponentsToStrip =
2532 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2533 if (PathComponentsToStrip < 0) {
2534 assert(PathComponentsToStrip != INT_MIN);
2535 int PathComponentsToKeep = -PathComponentsToStrip;
2536 auto I = llvm::sys::path::rbegin(FilenameString);
2537 auto E = llvm::sys::path::rend(FilenameString);
2538 while (I != E && --PathComponentsToKeep)
2541 FilenameString = FilenameString.substr(I - E);
2542 } else if (PathComponentsToStrip > 0) {
2543 auto I = llvm::sys::path::begin(FilenameString);
2544 auto E = llvm::sys::path::end(FilenameString);
2545 while (I != E && PathComponentsToStrip--)
2550 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2552 FilenameString = llvm::sys::path::filename(FilenameString);
2555 auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2556 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
2557 cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2558 Filename = FilenameGV.getPointer();
2559 Line = PLoc.getLine();
2560 Column = PLoc.getColumn();
2562 Filename = llvm::Constant::getNullValue(Int8PtrTy);
2566 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2567 Builder.getInt32(Column)};
2569 return llvm::ConstantStruct::getAnon(Data);
2573 /// \brief Specify under what conditions this check can be recovered
2574 enum class CheckRecoverableKind {
2575 /// Always terminate program execution if this check fails.
2577 /// Check supports recovering, runtime has both fatal (noreturn) and
2578 /// non-fatal handlers for this check.
2580 /// Runtime conditionally aborts, always need to support recovery.
2585 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
2586 assert(llvm::countPopulation(Kind) == 1);
2588 case SanitizerKind::Vptr:
2589 return CheckRecoverableKind::AlwaysRecoverable;
2590 case SanitizerKind::Return:
2591 case SanitizerKind::Unreachable:
2592 return CheckRecoverableKind::Unrecoverable;
2594 return CheckRecoverableKind::Recoverable;
2599 struct SanitizerHandlerInfo {
2600 char const *const Name;
2605 const SanitizerHandlerInfo SanitizerHandlers[] = {
2606 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2607 LIST_SANITIZER_CHECKS
2608 #undef SANITIZER_CHECK
2611 static void emitCheckHandlerCall(CodeGenFunction &CGF,
2612 llvm::FunctionType *FnType,
2613 ArrayRef<llvm::Value *> FnArgs,
2614 SanitizerHandler CheckHandler,
2615 CheckRecoverableKind RecoverKind, bool IsFatal,
2616 llvm::BasicBlock *ContBB) {
2617 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2618 bool NeedsAbortSuffix =
2619 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2620 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2621 const StringRef CheckName = CheckInfo.Name;
2622 std::string FnName =
2623 ("__ubsan_handle_" + CheckName +
2624 (CheckInfo.Version ? "_v" + llvm::utostr(CheckInfo.Version) : "") +
2625 (NeedsAbortSuffix ? "_abort" : ""))
2628 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2630 llvm::AttrBuilder B;
2632 B.addAttribute(llvm::Attribute::NoReturn)
2633 .addAttribute(llvm::Attribute::NoUnwind);
2635 B.addAttribute(llvm::Attribute::UWTable);
2637 llvm::Value *Fn = CGF.CGM.CreateRuntimeFunction(
2639 llvm::AttributeList::get(CGF.getLLVMContext(),
2640 llvm::AttributeList::FunctionIndex, B),
2642 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2644 HandlerCall->setDoesNotReturn();
2645 CGF.Builder.CreateUnreachable();
2647 CGF.Builder.CreateBr(ContBB);
2651 void CodeGenFunction::EmitCheck(
2652 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2653 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
2654 ArrayRef<llvm::Value *> DynamicArgs) {
2655 assert(IsSanitizerScope);
2656 assert(Checked.size() > 0);
2657 assert(CheckHandler >= 0 &&
2658 CheckHandler < sizeof(SanitizerHandlers) / sizeof(*SanitizerHandlers));
2659 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
2661 llvm::Value *FatalCond = nullptr;
2662 llvm::Value *RecoverableCond = nullptr;
2663 llvm::Value *TrapCond = nullptr;
2664 for (int i = 0, n = Checked.size(); i < n; ++i) {
2665 llvm::Value *Check = Checked[i].first;
2666 // -fsanitize-trap= overrides -fsanitize-recover=.
2667 llvm::Value *&Cond =
2668 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2670 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2673 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2677 EmitTrapCheck(TrapCond);
2678 if (!FatalCond && !RecoverableCond)
2681 llvm::Value *JointCond;
2682 if (FatalCond && RecoverableCond)
2683 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2685 JointCond = FatalCond ? FatalCond : RecoverableCond;
2688 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2689 assert(SanOpts.has(Checked[0].second));
2691 for (int i = 1, n = Checked.size(); i < n; ++i) {
2692 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2693 "All recoverable kinds in a single check must be same!");
2694 assert(SanOpts.has(Checked[i].second));
2698 llvm::BasicBlock *Cont = createBasicBlock("cont");
2699 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2700 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2701 // Give hint that we very much don't expect to execute the handler
2702 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2703 llvm::MDBuilder MDHelper(getLLVMContext());
2704 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2705 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2706 EmitBlock(Handlers);
2708 // Handler functions take an i8* pointing to the (handler-specific) static
2709 // information block, followed by a sequence of intptr_t arguments
2710 // representing operand values.
2711 SmallVector<llvm::Value *, 4> Args;
2712 SmallVector<llvm::Type *, 4> ArgTypes;
2713 Args.reserve(DynamicArgs.size() + 1);
2714 ArgTypes.reserve(DynamicArgs.size() + 1);
2716 // Emit handler arguments and create handler function type.
2717 if (!StaticArgs.empty()) {
2718 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2720 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2721 llvm::GlobalVariable::PrivateLinkage, Info);
2722 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2723 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2724 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
2725 ArgTypes.push_back(Int8PtrTy);
2728 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
2729 Args.push_back(EmitCheckValue(DynamicArgs[i]));
2730 ArgTypes.push_back(IntPtrTy);
2733 llvm::FunctionType *FnType =
2734 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
2736 if (!FatalCond || !RecoverableCond) {
2737 // Simple case: we need to generate a single handler call, either
2738 // fatal, or non-fatal.
2739 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
2740 (FatalCond != nullptr), Cont);
2742 // Emit two handler calls: first one for set of unrecoverable checks,
2743 // another one for recoverable.
2744 llvm::BasicBlock *NonFatalHandlerBB =
2745 createBasicBlock("non_fatal." + CheckName);
2746 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
2747 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
2748 EmitBlock(FatalHandlerBB);
2749 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
2751 EmitBlock(NonFatalHandlerBB);
2752 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
2759 void CodeGenFunction::EmitCfiSlowPathCheck(
2760 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
2761 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
2762 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
2764 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
2765 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
2767 llvm::MDBuilder MDHelper(getLLVMContext());
2768 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2769 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
2773 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
2775 llvm::CallInst *CheckCall;
2777 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2779 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2780 llvm::GlobalVariable::PrivateLinkage, Info);
2781 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2782 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2784 llvm::Constant *SlowPathDiagFn = CGM.getModule().getOrInsertFunction(
2785 "__cfi_slowpath_diag",
2786 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
2788 CheckCall = Builder.CreateCall(
2790 {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
2792 llvm::Constant *SlowPathFn = CGM.getModule().getOrInsertFunction(
2794 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
2795 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
2798 CheckCall->setDoesNotThrow();
2803 // Emit a stub for __cfi_check function so that the linker knows about this
2804 // symbol in LTO mode.
2805 void CodeGenFunction::EmitCfiCheckStub() {
2806 llvm::Module *M = &CGM.getModule();
2807 auto &Ctx = M->getContext();
2808 llvm::Function *F = llvm::Function::Create(
2809 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
2810 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
2811 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
2812 // FIXME: consider emitting an intrinsic call like
2813 // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
2814 // which can be lowered in CrossDSOCFI pass to the actual contents of
2815 // __cfi_check. This would allow inlining of __cfi_check calls.
2816 llvm::CallInst::Create(
2817 llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
2818 llvm::ReturnInst::Create(Ctx, nullptr, BB);
2821 // This function is basically a switch over the CFI failure kind, which is
2822 // extracted from CFICheckFailData (1st function argument). Each case is either
2823 // llvm.trap or a call to one of the two runtime handlers, based on
2824 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
2825 // failure kind) traps, but this should really never happen. CFICheckFailData
2826 // can be nullptr if the calling module has -fsanitize-trap behavior for this
2827 // check kind; in this case __cfi_check_fail traps as well.
2828 void CodeGenFunction::EmitCfiCheckFail() {
2829 SanitizerScope SanScope(this);
2830 FunctionArgList Args;
2831 ImplicitParamDecl ArgData(getContext(), nullptr, SourceLocation(), nullptr,
2832 getContext().VoidPtrTy);
2833 ImplicitParamDecl ArgAddr(getContext(), nullptr, SourceLocation(), nullptr,
2834 getContext().VoidPtrTy);
2835 Args.push_back(&ArgData);
2836 Args.push_back(&ArgAddr);
2838 const CGFunctionInfo &FI =
2839 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
2841 llvm::Function *F = llvm::Function::Create(
2842 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
2843 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
2844 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
2846 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
2850 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
2851 CGM.getContext().VoidPtrTy, ArgData.getLocation());
2853 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
2854 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
2856 // Data == nullptr means the calling module has trap behaviour for this check.
2857 llvm::Value *DataIsNotNullPtr =
2858 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
2859 EmitTrapCheck(DataIsNotNullPtr);
2861 llvm::StructType *SourceLocationTy =
2862 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty, nullptr);
2863 llvm::StructType *CfiCheckFailDataTy =
2864 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy, nullptr);
2866 llvm::Value *V = Builder.CreateConstGEP2_32(
2868 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
2870 Address CheckKindAddr(V, getIntAlign());
2871 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
2873 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
2874 CGM.getLLVMContext(),
2875 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
2876 llvm::Value *ValidVtable = Builder.CreateZExt(
2877 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
2878 {Addr, AllVtables}),
2881 const std::pair<int, SanitizerMask> CheckKinds[] = {
2882 {CFITCK_VCall, SanitizerKind::CFIVCall},
2883 {CFITCK_NVCall, SanitizerKind::CFINVCall},
2884 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
2885 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
2886 {CFITCK_ICall, SanitizerKind::CFIICall}};
2888 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
2889 for (auto CheckKindMaskPair : CheckKinds) {
2890 int Kind = CheckKindMaskPair.first;
2891 SanitizerMask Mask = CheckKindMaskPair.second;
2893 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
2894 if (CGM.getLangOpts().Sanitize.has(Mask))
2895 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
2896 {Data, Addr, ValidVtable});
2898 EmitTrapCheck(Cond);
2902 // The only reference to this function will be created during LTO link.
2903 // Make sure it survives until then.
2904 CGM.addUsedGlobal(F);
2907 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
2908 llvm::BasicBlock *Cont = createBasicBlock("cont");
2910 // If we're optimizing, collapse all calls to trap down to just one per
2911 // function to save on code size.
2912 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
2913 TrapBB = createBasicBlock("trap");
2914 Builder.CreateCondBr(Checked, Cont, TrapBB);
2916 llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
2917 TrapCall->setDoesNotReturn();
2918 TrapCall->setDoesNotThrow();
2919 Builder.CreateUnreachable();
2921 Builder.CreateCondBr(Checked, Cont, TrapBB);
2927 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
2928 llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
2930 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
2931 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
2932 CGM.getCodeGenOpts().TrapFuncName);
2933 TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
2939 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
2940 AlignmentSource *AlignSource) {
2941 assert(E->getType()->isArrayType() &&
2942 "Array to pointer decay must have array source type!");
2944 // Expressions of array type can't be bitfields or vector elements.
2945 LValue LV = EmitLValue(E);
2946 Address Addr = LV.getAddress();
2947 if (AlignSource) *AlignSource = LV.getAlignmentSource();
2949 // If the array type was an incomplete type, we need to make sure
2950 // the decay ends up being the right type.
2951 llvm::Type *NewTy = ConvertType(E->getType());
2952 Addr = Builder.CreateElementBitCast(Addr, NewTy);
2954 // Note that VLA pointers are always decayed, so we don't need to do
2956 if (!E->getType()->isVariableArrayType()) {
2957 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
2958 "Expected pointer to array");
2959 Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
2962 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
2963 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
2966 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
2967 /// array to pointer, return the array subexpression.
2968 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
2969 // If this isn't just an array->pointer decay, bail out.
2970 const auto *CE = dyn_cast<CastExpr>(E);
2971 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
2974 // If this is a decay from variable width array, bail out.
2975 const Expr *SubExpr = CE->getSubExpr();
2976 if (SubExpr->getType()->isVariableArrayType())
2982 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
2984 ArrayRef<llvm::Value*> indices,
2986 const llvm::Twine &name = "arrayidx") {
2988 return CGF.Builder.CreateInBoundsGEP(ptr, indices, name);
2990 return CGF.Builder.CreateGEP(ptr, indices, name);
2994 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
2996 CharUnits eltSize) {
2997 // If we have a constant index, we can use the exact offset of the
2998 // element we're accessing.
2999 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3000 CharUnits offset = constantIdx->getZExtValue() * eltSize;
3001 return arrayAlign.alignmentAtOffset(offset);
3003 // Otherwise, use the worst-case alignment for any element.
3005 return arrayAlign.alignmentOfArrayElement(eltSize);
3009 static QualType getFixedSizeElementType(const ASTContext &ctx,
3010 const VariableArrayType *vla) {
3013 eltType = vla->getElementType();
3014 } while ((vla = ctx.getAsVariableArrayType(eltType)));
3018 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
3019 ArrayRef<llvm::Value*> indices,
3020 QualType eltType, bool inbounds,
3021 const llvm::Twine &name = "arrayidx") {
3022 // All the indices except that last must be zero.
3024 for (auto idx : indices.drop_back())
3025 assert(isa<llvm::ConstantInt>(idx) &&
3026 cast<llvm::ConstantInt>(idx)->isZero());
3029 // Determine the element size of the statically-sized base. This is
3030 // the thing that the indices are expressed in terms of.
3031 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3032 eltType = getFixedSizeElementType(CGF.getContext(), vla);
3035 // We can use that to compute the best alignment of the element.
3036 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3037 CharUnits eltAlign =
3038 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3040 llvm::Value *eltPtr =
3041 emitArraySubscriptGEP(CGF, addr.getPointer(), indices, inbounds, name);
3042 return Address(eltPtr, eltAlign);
3045 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3047 // The index must always be an integer, which is not an aggregate. Emit it
3048 // in lexical order (this complexity is, sadly, required by C++17).
3049 llvm::Value *IdxPre =
3050 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3051 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3053 if (E->getLHS() != E->getIdx()) {
3054 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3055 Idx = EmitScalarExpr(E->getIdx());
3058 QualType IdxTy = E->getIdx()->getType();
3059 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3061 if (SanOpts.has(SanitizerKind::ArrayBounds))
3062 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3064 // Extend or truncate the index type to 32 or 64-bits.
3065 if (Promote && Idx->getType() != IntPtrTy)
3066 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3072 // If the base is a vector type, then we are forming a vector element lvalue
3073 // with this subscript.
3074 if (E->getBase()->getType()->isVectorType() &&
3075 !isa<ExtVectorElementExpr>(E->getBase())) {
3076 // Emit the vector as an lvalue to get its address.
3077 LValue LHS = EmitLValue(E->getBase());
3078 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3079 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3080 return LValue::MakeVectorElt(LHS.getAddress(), Idx,
3081 E->getBase()->getType(),
3082 LHS.getAlignmentSource());
3085 // All the other cases basically behave like simple offsetting.
3087 // Handle the extvector case we ignored above.
3088 if (isa<ExtVectorElementExpr>(E->getBase())) {
3089 LValue LV = EmitLValue(E->getBase());
3090 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3091 Address Addr = EmitExtVectorElementLValue(LV);
3093 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3094 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true);
3095 return MakeAddrLValue(Addr, EltType, LV.getAlignmentSource());
3098 AlignmentSource AlignSource;
3099 Address Addr = Address::invalid();
3100 if (const VariableArrayType *vla =
3101 getContext().getAsVariableArrayType(E->getType())) {
3102 // The base must be a pointer, which is not an aggregate. Emit
3103 // it. It needs to be emitted first in case it's what captures
3105 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
3106 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3108 // The element count here is the total number of non-VLA elements.
3109 llvm::Value *numElements = getVLASize(vla).first;
3111 // Effectively, the multiply by the VLA size is part of the GEP.
3112 // GEP indexes are signed, and scaling an index isn't permitted to
3113 // signed-overflow, so we use the same semantics for our explicit
3114 // multiply. We suppress this if overflow is not undefined behavior.
3115 if (getLangOpts().isSignedOverflowDefined()) {
3116 Idx = Builder.CreateMul(Idx, numElements);
3118 Idx = Builder.CreateNSWMul(Idx, numElements);
3121 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3122 !getLangOpts().isSignedOverflowDefined());
3124 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3125 // Indexing over an interface, as in "NSString *P; P[4];"
3127 // Emit the base pointer.
3128 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
3129 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3131 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3132 llvm::Value *InterfaceSizeVal =
3133 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3135 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3137 // We don't necessarily build correct LLVM struct types for ObjC
3138 // interfaces, so we can't rely on GEP to do this scaling
3139 // correctly, so we need to cast to i8*. FIXME: is this actually
3140 // true? A lot of other things in the fragile ABI would break...
3141 llvm::Type *OrigBaseTy = Addr.getType();
3142 Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3145 CharUnits EltAlign =
3146 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3147 llvm::Value *EltPtr =
3148 emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false);
3149 Addr = Address(EltPtr, EltAlign);
3152 Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3153 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3154 // If this is A[i] where A is an array, the frontend will have decayed the
3155 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3156 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3157 // "gep x, i" here. Emit one "gep A, 0, i".
3158 assert(Array->getType()->isArrayType() &&
3159 "Array to pointer decay must have array source type!");
3161 // For simple multidimensional array indexing, set the 'accessed' flag for
3162 // better bounds-checking of the base expression.
3163 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3164 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3166 ArrayLV = EmitLValue(Array);
3167 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3169 // Propagate the alignment from the array itself to the result.
3170 Addr = emitArraySubscriptGEP(*this, ArrayLV.getAddress(),
3171 {CGM.getSize(CharUnits::Zero()), Idx},
3173 !getLangOpts().isSignedOverflowDefined());
3174 AlignSource = ArrayLV.getAlignmentSource();
3176 // The base must be a pointer; emit it with an estimate of its alignment.
3177 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
3178 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3179 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3180 !getLangOpts().isSignedOverflowDefined());
3183 LValue LV = MakeAddrLValue(Addr, E->getType(), AlignSource);
3185 // TODO: Preserve/extend path TBAA metadata?
3187 if (getLangOpts().ObjC1 &&
3188 getLangOpts().getGC() != LangOptions::NonGC) {
3189 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3190 setObjCGCLValueClass(getContext(), E, LV);
3195 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
3196 AlignmentSource &AlignSource,
3197 QualType BaseTy, QualType ElTy,
3198 bool IsLowerBound) {
3200 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3201 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3202 if (BaseTy->isArrayType()) {
3203 Address Addr = BaseLVal.getAddress();
3204 AlignSource = BaseLVal.getAlignmentSource();
3206 // If the array type was an incomplete type, we need to make sure
3207 // the decay ends up being the right type.
3208 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3209 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3211 // Note that VLA pointers are always decayed, so we don't need to do
3213 if (!BaseTy->isVariableArrayType()) {
3214 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3215 "Expected pointer to array");
3216 Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
3220 return CGF.Builder.CreateElementBitCast(Addr,
3221 CGF.ConvertTypeForMem(ElTy));
3223 CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &AlignSource);
3224 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3226 return CGF.EmitPointerWithAlignment(Base, &AlignSource);
3229 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3230 bool IsLowerBound) {
3233 dyn_cast<OMPArraySectionExpr>(E->getBase()->IgnoreParenImpCasts()))
3234 BaseTy = OMPArraySectionExpr::getBaseOriginalType(ASE);
3236 BaseTy = E->getBase()->getType();
3237 QualType ResultExprTy;
3238 if (auto *AT = getContext().getAsArrayType(BaseTy))
3239 ResultExprTy = AT->getElementType();
3241 ResultExprTy = BaseTy->getPointeeType();
3242 llvm::Value *Idx = nullptr;
3243 if (IsLowerBound || E->getColonLoc().isInvalid()) {
3244 // Requesting lower bound or upper bound, but without provided length and
3245 // without ':' symbol for the default length -> length = 1.
3246 // Idx = LowerBound ?: 0;
3247 if (auto *LowerBound = E->getLowerBound()) {
3248 Idx = Builder.CreateIntCast(
3249 EmitScalarExpr(LowerBound), IntPtrTy,
3250 LowerBound->getType()->hasSignedIntegerRepresentation());
3252 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3254 // Try to emit length or lower bound as constant. If this is possible, 1
3255 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3256 // IR (LB + Len) - 1.
3257 auto &C = CGM.getContext();
3258 auto *Length = E->getLength();
3259 llvm::APSInt ConstLength;
3261 // Idx = LowerBound + Length - 1;
3262 if (Length->isIntegerConstantExpr(ConstLength, C)) {
3263 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3266 auto *LowerBound = E->getLowerBound();
3267 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3268 if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3269 ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3270 LowerBound = nullptr;
3274 else if (!LowerBound)
3277 if (Length || LowerBound) {
3278 auto *LowerBoundVal =
3280 ? Builder.CreateIntCast(
3281 EmitScalarExpr(LowerBound), IntPtrTy,
3282 LowerBound->getType()->hasSignedIntegerRepresentation())
3283 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3286 ? Builder.CreateIntCast(
3287 EmitScalarExpr(Length), IntPtrTy,
3288 Length->getType()->hasSignedIntegerRepresentation())
3289 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3290 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3292 !getLangOpts().isSignedOverflowDefined());
3293 if (Length && LowerBound) {
3294 Idx = Builder.CreateSub(
3295 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3296 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3299 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3301 // Idx = ArraySize - 1;
3302 QualType ArrayTy = BaseTy->isPointerType()
3303 ? E->getBase()->IgnoreParenImpCasts()->getType()
3305 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3306 Length = VAT->getSizeExpr();
3307 if (Length->isIntegerConstantExpr(ConstLength, C))
3310 auto *CAT = C.getAsConstantArrayType(ArrayTy);
3311 ConstLength = CAT->getSize();
3314 auto *LengthVal = Builder.CreateIntCast(
3315 EmitScalarExpr(Length), IntPtrTy,
3316 Length->getType()->hasSignedIntegerRepresentation());
3317 Idx = Builder.CreateSub(
3318 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3319 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3321 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3323 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3329 Address EltPtr = Address::invalid();
3330 AlignmentSource AlignSource;
3331 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3332 // The base must be a pointer, which is not an aggregate. Emit
3333 // it. It needs to be emitted first in case it's what captures
3336 emitOMPArraySectionBase(*this, E->getBase(), AlignSource, BaseTy,
3337 VLA->getElementType(), IsLowerBound);
3338 // The element count here is the total number of non-VLA elements.
3339 llvm::Value *NumElements = getVLASize(VLA).first;
3341 // Effectively, the multiply by the VLA size is part of the GEP.
3342 // GEP indexes are signed, and scaling an index isn't permitted to
3343 // signed-overflow, so we use the same semantics for our explicit
3344 // multiply. We suppress this if overflow is not undefined behavior.
3345 if (getLangOpts().isSignedOverflowDefined())
3346 Idx = Builder.CreateMul(Idx, NumElements);
3348 Idx = Builder.CreateNSWMul(Idx, NumElements);
3349 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3350 !getLangOpts().isSignedOverflowDefined());
3351 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3352 // If this is A[i] where A is an array, the frontend will have decayed the
3353 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3354 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3355 // "gep x, i" here. Emit one "gep A, 0, i".
3356 assert(Array->getType()->isArrayType() &&
3357 "Array to pointer decay must have array source type!");
3359 // For simple multidimensional array indexing, set the 'accessed' flag for
3360 // better bounds-checking of the base expression.
3361 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3362 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3364 ArrayLV = EmitLValue(Array);
3366 // Propagate the alignment from the array itself to the result.
3367 EltPtr = emitArraySubscriptGEP(
3368 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3369 ResultExprTy, !getLangOpts().isSignedOverflowDefined());
3370 AlignSource = ArrayLV.getAlignmentSource();
3372 Address Base = emitOMPArraySectionBase(*this, E->getBase(), AlignSource,
3373 BaseTy, ResultExprTy, IsLowerBound);
3374 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3375 !getLangOpts().isSignedOverflowDefined());
3378 return MakeAddrLValue(EltPtr, ResultExprTy, AlignSource);
3381 LValue CodeGenFunction::
3382 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
3383 // Emit the base vector as an l-value.
3386 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3388 // If it is a pointer to a vector, emit the address and form an lvalue with
3390 AlignmentSource AlignSource;
3391 Address Ptr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
3392 const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3393 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), AlignSource);
3394 Base.getQuals().removeObjCGCAttr();
3395 } else if (E->getBase()->isGLValue()) {
3396 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3397 // emit the base as an lvalue.
3398 assert(E->getBase()->getType()->isVectorType());
3399 Base = EmitLValue(E->getBase());
3401 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3402 assert(E->getBase()->getType()->isVectorType() &&
3403 "Result must be a vector");
3404 llvm::Value *Vec = EmitScalarExpr(E->getBase());
3406 // Store the vector to memory (because LValue wants an address).
3407 Address VecMem = CreateMemTemp(E->getBase()->getType());
3408 Builder.CreateStore(Vec, VecMem);
3409 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3410 AlignmentSource::Decl);
3414 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
3416 // Encode the element access list into a vector of unsigned indices.
3417 SmallVector<uint32_t, 4> Indices;
3418 E->getEncodedElementAccess(Indices);
3420 if (Base.isSimple()) {
3421 llvm::Constant *CV =
3422 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3423 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3424 Base.getAlignmentSource());
3426 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3428 llvm::Constant *BaseElts = Base.getExtVectorElts();
3429 SmallVector<llvm::Constant *, 4> CElts;
3431 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3432 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3433 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3434 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
3435 Base.getAlignmentSource());
3438 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
3439 Expr *BaseExpr = E->getBase();
3441 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3444 AlignmentSource AlignSource;
3445 Address Addr = EmitPointerWithAlignment(BaseExpr, &AlignSource);
3446 QualType PtrTy = BaseExpr->getType()->getPointeeType();
3447 SanitizerSet SkippedChecks;
3448 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3450 SkippedChecks.set(SanitizerKind::Alignment, true);
3451 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3452 SkippedChecks.set(SanitizerKind::Null, true);
3453 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3454 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3455 BaseLV = MakeAddrLValue(Addr, PtrTy, AlignSource);
3457 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3459 NamedDecl *ND = E->getMemberDecl();
3460 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3461 LValue LV = EmitLValueForField(BaseLV, Field);
3462 setObjCGCLValueClass(getContext(), E, LV);
3466 if (auto *VD = dyn_cast<VarDecl>(ND))
3467 return EmitGlobalVarDeclLValue(*this, E, VD);
3469 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3470 return EmitFunctionDeclLValue(*this, E, FD);
3472 llvm_unreachable("Unhandled member declaration!");
3475 /// Given that we are currently emitting a lambda, emit an l-value for
3476 /// one of its members.
3477 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
3478 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3479 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3480 QualType LambdaTagType =
3481 getContext().getTagDeclType(Field->getParent());
3482 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3483 return EmitLValueForField(LambdaLV, Field);
3486 /// Drill down to the storage of a field without walking into
3487 /// reference types.
3489 /// The resulting address doesn't necessarily have the right type.
3490 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
3491 const FieldDecl *field) {
3492 const RecordDecl *rec = field->getParent();
3495 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3498 // Adjust the alignment down to the given offset.
3499 // As a special case, if the LLVM field index is 0, we know that this
3501 assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
3502 .getFieldOffset(field->getFieldIndex()) == 0) &&
3503 "LLVM field at index zero had non-zero offset?");
3505 auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
3506 auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
3507 offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
3510 return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
3513 LValue CodeGenFunction::EmitLValueForField(LValue base,
3514 const FieldDecl *field) {
3515 AlignmentSource fieldAlignSource =
3516 getFieldAlignmentSource(base.getAlignmentSource());
3518 if (field->isBitField()) {
3519 const CGRecordLayout &RL =
3520 CGM.getTypes().getCGRecordLayout(field->getParent());
3521 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3522 Address Addr = base.getAddress();
3523 unsigned Idx = RL.getLLVMFieldNo(field);
3525 // For structs, we GEP to the field that the record layout suggests.
3526 Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
3528 // Get the access type.
3529 llvm::Type *FieldIntTy =
3530 llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3531 if (Addr.getElementType() != FieldIntTy)
3532 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3534 QualType fieldType =
3535 field->getType().withCVRQualifiers(base.getVRQualifiers());
3536 return LValue::MakeBitfield(Addr, Info, fieldType, fieldAlignSource);
3539 const RecordDecl *rec = field->getParent();
3540 QualType type = field->getType();
3542 bool mayAlias = rec->hasAttr<MayAliasAttr>();
3544 Address addr = base.getAddress();
3545 unsigned cvr = base.getVRQualifiers();
3546 bool TBAAPath = CGM.getCodeGenOpts().StructPathTBAA;
3547 if (rec->isUnion()) {
3548 // For unions, there is no pointer adjustment.
3549 assert(!type->isReferenceType() && "union has reference member");
3550 // TODO: handle path-aware TBAA for union.
3553 // For structs, we GEP to the field that the record layout suggests.
3554 addr = emitAddrOfFieldStorage(*this, addr, field);
3556 // If this is a reference field, load the reference right now.
3557 if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
3558 llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
3559 if (cvr & Qualifiers::Volatile) load->setVolatile(true);
3561 // Loading the reference will disable path-aware TBAA.
3563 if (CGM.shouldUseTBAA()) {
3566 tbaa = CGM.getTBAAInfo(getContext().CharTy);
3568 tbaa = CGM.getTBAAInfo(type);
3570 CGM.DecorateInstructionWithTBAA(load, tbaa);
3574 type = refType->getPointeeType();
3576 CharUnits alignment =
3577 getNaturalTypeAlignment(type, &fieldAlignSource, /*pointee*/ true);
3578 addr = Address(load, alignment);
3580 // Qualifiers on the struct don't apply to the referencee, and
3581 // we'll pick up CVR from the actual type later, so reset these
3582 // additional qualifiers now.
3587 // Make sure that the address is pointing to the right type. This is critical
3588 // for both unions and structs. A union needs a bitcast, a struct element
3589 // will need a bitcast if the LLVM type laid out doesn't match the desired
3591 addr = Builder.CreateElementBitCast(addr,
3592 CGM.getTypes().ConvertTypeForMem(type),
3595 if (field->hasAttr<AnnotateAttr>())
3596 addr = EmitFieldAnnotations(field, addr);
3598 LValue LV = MakeAddrLValue(addr, type, fieldAlignSource);
3599 LV.getQuals().addCVRQualifiers(cvr);
3601 const ASTRecordLayout &Layout =
3602 getContext().getASTRecordLayout(field->getParent());
3603 // Set the base type to be the base type of the base LValue and
3604 // update offset to be relative to the base type.
3605 LV.setTBAABaseType(mayAlias ? getContext().CharTy : base.getTBAABaseType());
3606 LV.setTBAAOffset(mayAlias ? 0 : base.getTBAAOffset() +
3607 Layout.getFieldOffset(field->getFieldIndex()) /
3608 getContext().getCharWidth());
3611 // __weak attribute on a field is ignored.
3612 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3613 LV.getQuals().removeObjCGCAttr();
3615 // Fields of may_alias structs act like 'char' for TBAA purposes.
3616 // FIXME: this should get propagated down through anonymous structs
3618 if (mayAlias && LV.getTBAAInfo())
3619 LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
3625 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
3626 const FieldDecl *Field) {
3627 QualType FieldType = Field->getType();
3629 if (!FieldType->isReferenceType())
3630 return EmitLValueForField(Base, Field);
3632 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3634 // Make sure that the address is pointing to the right type.
3635 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3636 V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3638 // TODO: access-path TBAA?
3639 auto FieldAlignSource = getFieldAlignmentSource(Base.getAlignmentSource());
3640 return MakeAddrLValue(V, FieldType, FieldAlignSource);
3643 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
3644 if (E->isFileScope()) {
3645 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
3646 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
3648 if (E->getType()->isVariablyModifiedType())
3649 // make sure to emit the VLA size.
3650 EmitVariablyModifiedType(E->getType());
3652 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
3653 const Expr *InitExpr = E->getInitializer();
3654 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
3656 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
3662 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
3663 if (!E->isGLValue())
3664 // Initializing an aggregate temporary in C++11: T{...}.
3665 return EmitAggExprToLValue(E);
3667 // An lvalue initializer list must be initializing a reference.
3668 assert(E->isTransparent() && "non-transparent glvalue init list");
3669 return EmitLValue(E->getInit(0));
3672 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
3673 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
3674 /// LValue is returned and the current block has been terminated.
3675 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
3676 const Expr *Operand) {
3677 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
3678 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
3682 return CGF.EmitLValue(Operand);
3685 LValue CodeGenFunction::
3686 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
3687 if (!expr->isGLValue()) {
3688 // ?: here should be an aggregate.
3689 assert(hasAggregateEvaluationKind(expr->getType()) &&
3690 "Unexpected conditional operator!");
3691 return EmitAggExprToLValue(expr);
3694 OpaqueValueMapping binding(*this, expr);
3696 const Expr *condExpr = expr->getCond();
3698 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
3699 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
3700 if (!CondExprBool) std::swap(live, dead);
3702 if (!ContainsLabel(dead)) {
3703 // If the true case is live, we need to track its region.
3705 incrementProfileCounter(expr);
3706 return EmitLValue(live);
3710 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
3711 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
3712 llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
3714 ConditionalEvaluation eval(*this);
3715 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
3717 // Any temporaries created here are conditional.
3718 EmitBlock(lhsBlock);
3719 incrementProfileCounter(expr);
3721 Optional<LValue> lhs =
3722 EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
3725 if (lhs && !lhs->isSimple())
3726 return EmitUnsupportedLValue(expr, "conditional operator");
3728 lhsBlock = Builder.GetInsertBlock();
3730 Builder.CreateBr(contBlock);
3732 // Any temporaries created here are conditional.
3733 EmitBlock(rhsBlock);
3735 Optional<LValue> rhs =
3736 EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
3738 if (rhs && !rhs->isSimple())
3739 return EmitUnsupportedLValue(expr, "conditional operator");
3740 rhsBlock = Builder.GetInsertBlock();
3742 EmitBlock(contBlock);
3745 llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
3747 phi->addIncoming(lhs->getPointer(), lhsBlock);
3748 phi->addIncoming(rhs->getPointer(), rhsBlock);
3749 Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
3750 AlignmentSource alignSource =
3751 std::max(lhs->getAlignmentSource(), rhs->getAlignmentSource());
3752 return MakeAddrLValue(result, expr->getType(), alignSource);
3754 assert((lhs || rhs) &&
3755 "both operands of glvalue conditional are throw-expressions?");
3756 return lhs ? *lhs : *rhs;
3760 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
3761 /// type. If the cast is to a reference, we can have the usual lvalue result,
3762 /// otherwise if a cast is needed by the code generator in an lvalue context,
3763 /// then it must mean that we need the address of an aggregate in order to
3764 /// access one of its members. This can happen for all the reasons that casts
3765 /// are permitted with aggregate result, including noop aggregate casts, and
3766 /// cast from scalar to union.
3767 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
3768 switch (E->getCastKind()) {
3771 case CK_ArrayToPointerDecay:
3772 case CK_FunctionToPointerDecay:
3773 case CK_NullToMemberPointer:
3774 case CK_NullToPointer:
3775 case CK_IntegralToPointer:
3776 case CK_PointerToIntegral:
3777 case CK_PointerToBoolean:
3778 case CK_VectorSplat:
3779 case CK_IntegralCast:
3780 case CK_BooleanToSignedIntegral:
3781 case CK_IntegralToBoolean:
3782 case CK_IntegralToFloating:
3783 case CK_FloatingToIntegral:
3784 case CK_FloatingToBoolean:
3785 case CK_FloatingCast:
3786 case CK_FloatingRealToComplex:
3787 case CK_FloatingComplexToReal:
3788 case CK_FloatingComplexToBoolean:
3789 case CK_FloatingComplexCast:
3790 case CK_FloatingComplexToIntegralComplex:
3791 case CK_IntegralRealToComplex:
3792 case CK_IntegralComplexToReal:
3793 case CK_IntegralComplexToBoolean:
3794 case CK_IntegralComplexCast:
3795 case CK_IntegralComplexToFloatingComplex:
3796 case CK_DerivedToBaseMemberPointer:
3797 case CK_BaseToDerivedMemberPointer:
3798 case CK_MemberPointerToBoolean:
3799 case CK_ReinterpretMemberPointer:
3800 case CK_AnyPointerToBlockPointerCast:
3801 case CK_ARCProduceObject:
3802 case CK_ARCConsumeObject:
3803 case CK_ARCReclaimReturnedObject:
3804 case CK_ARCExtendBlockObject:
3805 case CK_CopyAndAutoreleaseBlockObject:
3806 case CK_AddressSpaceConversion:
3807 case CK_IntToOCLSampler:
3808 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
3811 llvm_unreachable("dependent cast kind in IR gen!");
3813 case CK_BuiltinFnToFnPtr:
3814 llvm_unreachable("builtin functions are handled elsewhere");
3816 // These are never l-values; just use the aggregate emission code.
3817 case CK_NonAtomicToAtomic:
3818 case CK_AtomicToNonAtomic:
3819 return EmitAggExprToLValue(E);
3822 LValue LV = EmitLValue(E->getSubExpr());
3823 Address V = LV.getAddress();
3824 const auto *DCE = cast<CXXDynamicCastExpr>(E);
3825 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
3828 case CK_ConstructorConversion:
3829 case CK_UserDefinedConversion:
3830 case CK_CPointerToObjCPointerCast:
3831 case CK_BlockPointerToObjCPointerCast:
3833 case CK_LValueToRValue:
3834 return EmitLValue(E->getSubExpr());
3836 case CK_UncheckedDerivedToBase:
3837 case CK_DerivedToBase: {
3838 const RecordType *DerivedClassTy =
3839 E->getSubExpr()->getType()->getAs<RecordType>();
3840 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3842 LValue LV = EmitLValue(E->getSubExpr());
3843 Address This = LV.getAddress();
3845 // Perform the derived-to-base conversion
3846 Address Base = GetAddressOfBaseClass(
3847 This, DerivedClassDecl, E->path_begin(), E->path_end(),
3848 /*NullCheckValue=*/false, E->getExprLoc());
3850 return MakeAddrLValue(Base, E->getType(), LV.getAlignmentSource());
3853 return EmitAggExprToLValue(E);
3854 case CK_BaseToDerived: {
3855 const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
3856 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3858 LValue LV = EmitLValue(E->getSubExpr());
3860 // Perform the base-to-derived conversion
3862 GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
3863 E->path_begin(), E->path_end(),
3864 /*NullCheckValue=*/false);
3866 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
3867 // performed and the object is not of the derived type.
3868 if (sanitizePerformTypeCheck())
3869 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
3870 Derived.getPointer(), E->getType());
3872 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
3873 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
3874 /*MayBeNull=*/false,
3875 CFITCK_DerivedCast, E->getLocStart());
3877 return MakeAddrLValue(Derived, E->getType(), LV.getAlignmentSource());
3879 case CK_LValueBitCast: {
3880 // This must be a reinterpret_cast (or c-style equivalent).
3881 const auto *CE = cast<ExplicitCastExpr>(E);
3883 CGM.EmitExplicitCastExprType(CE, this);
3884 LValue LV = EmitLValue(E->getSubExpr());
3885 Address V = Builder.CreateBitCast(LV.getAddress(),
3886 ConvertType(CE->getTypeAsWritten()));
3888 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
3889 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
3890 /*MayBeNull=*/false,
3891 CFITCK_UnrelatedCast, E->getLocStart());
3893 return MakeAddrLValue(V, E->getType(), LV.getAlignmentSource());
3895 case CK_ObjCObjectLValueCast: {
3896 LValue LV = EmitLValue(E->getSubExpr());
3897 Address V = Builder.CreateElementBitCast(LV.getAddress(),
3898 ConvertType(E->getType()));
3899 return MakeAddrLValue(V, E->getType(), LV.getAlignmentSource());
3901 case CK_ZeroToOCLQueue:
3902 llvm_unreachable("NULL to OpenCL queue lvalue cast is not valid");
3903 case CK_ZeroToOCLEvent:
3904 llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
3907 llvm_unreachable("Unhandled lvalue cast kind?");
3910 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
3911 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
3912 return getOpaqueLValueMapping(e);
3915 RValue CodeGenFunction::EmitRValueForField(LValue LV,
3916 const FieldDecl *FD,
3917 SourceLocation Loc) {
3918 QualType FT = FD->getType();
3919 LValue FieldLV = EmitLValueForField(LV, FD);
3920 switch (getEvaluationKind(FT)) {
3922 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
3924 return FieldLV.asAggregateRValue();
3926 // This routine is used to load fields one-by-one to perform a copy, so
3927 // don't load reference fields.
3928 if (FD->getType()->isReferenceType())
3929 return RValue::get(FieldLV.getPointer());
3930 return EmitLoadOfLValue(FieldLV, Loc);
3932 llvm_unreachable("bad evaluation kind");
3935 //===--------------------------------------------------------------------===//
3936 // Expression Emission
3937 //===--------------------------------------------------------------------===//
3939 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
3940 ReturnValueSlot ReturnValue) {
3941 // Builtins never have block type.
3942 if (E->getCallee()->getType()->isBlockPointerType())
3943 return EmitBlockCallExpr(E, ReturnValue);
3945 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
3946 return EmitCXXMemberCallExpr(CE, ReturnValue);
3948 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
3949 return EmitCUDAKernelCallExpr(CE, ReturnValue);
3951 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
3952 if (const CXXMethodDecl *MD =
3953 dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
3954 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
3956 CGCallee callee = EmitCallee(E->getCallee());
3958 if (callee.isBuiltin()) {
3959 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
3963 if (callee.isPseudoDestructor()) {
3964 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
3967 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
3970 /// Emit a CallExpr without considering whether it might be a subclass.
3971 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
3972 ReturnValueSlot ReturnValue) {
3973 CGCallee Callee = EmitCallee(E->getCallee());
3974 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
3977 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
3978 if (auto builtinID = FD->getBuiltinID()) {
3979 return CGCallee::forBuiltin(builtinID, FD);
3982 llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
3983 return CGCallee::forDirect(calleePtr, FD);
3986 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
3987 E = E->IgnoreParens();
3989 // Look through function-to-pointer decay.
3990 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
3991 if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
3992 ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
3993 return EmitCallee(ICE->getSubExpr());
3996 // Resolve direct calls.
3997 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
3998 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
3999 return EmitDirectCallee(*this, FD);
4001 } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4002 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4003 EmitIgnoredExpr(ME->getBase());
4004 return EmitDirectCallee(*this, FD);
4007 // Look through template substitutions.
4008 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4009 return EmitCallee(NTTP->getReplacement());
4011 // Treat pseudo-destructor calls differently.
4012 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4013 return CGCallee::forPseudoDestructor(PDE);
4016 // Otherwise, we have an indirect reference.
4017 llvm::Value *calleePtr;
4018 QualType functionType;
4019 if (auto ptrType = E->getType()->getAs<PointerType>()) {
4020 calleePtr = EmitScalarExpr(E);
4021 functionType = ptrType->getPointeeType();
4023 functionType = E->getType();
4024 calleePtr = EmitLValue(E).getPointer();
4026 assert(functionType->isFunctionType());
4027 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(),
4028 E->getReferencedDeclOfCallee());
4029 CGCallee callee(calleeInfo, calleePtr);
4033 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
4034 // Comma expressions just emit their LHS then their RHS as an l-value.
4035 if (E->getOpcode() == BO_Comma) {
4036 EmitIgnoredExpr(E->getLHS());
4037 EnsureInsertPoint();
4038 return EmitLValue(E->getRHS());
4041 if (E->getOpcode() == BO_PtrMemD ||
4042 E->getOpcode() == BO_PtrMemI)
4043 return EmitPointerToDataMemberBinaryExpr(E);
4045 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4047 // Note that in all of these cases, __block variables need the RHS
4048 // evaluated first just in case the variable gets moved by the RHS.
4050 switch (getEvaluationKind(E->getType())) {
4052 switch (E->getLHS()->getType().getObjCLifetime()) {
4053 case Qualifiers::OCL_Strong:
4054 return EmitARCStoreStrong(E, /*ignored*/ false).first;
4056 case Qualifiers::OCL_Autoreleasing:
4057 return EmitARCStoreAutoreleasing(E).first;
4059 // No reason to do any of these differently.
4060 case Qualifiers::OCL_None:
4061 case Qualifiers::OCL_ExplicitNone:
4062 case Qualifiers::OCL_Weak:
4066 RValue RV = EmitAnyExpr(E->getRHS());
4067 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
4069 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
4070 EmitStoreThroughLValue(RV, LV);
4075 return EmitComplexAssignmentLValue(E);
4078 return EmitAggExprToLValue(E);
4080 llvm_unreachable("bad evaluation kind");
4083 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
4084 RValue RV = EmitCallExpr(E);
4087 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4088 AlignmentSource::Decl);
4090 assert(E->getCallReturnType(getContext())->isReferenceType() &&
4091 "Can't have a scalar return unless the return type is a "
4094 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4097 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
4098 // FIXME: This shouldn't require another copy.
4099 return EmitAggExprToLValue(E);
4102 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
4103 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
4104 && "binding l-value to type which needs a temporary");
4105 AggValueSlot Slot = CreateAggTemp(E->getType());
4106 EmitCXXConstructExpr(E, Slot);
4107 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4108 AlignmentSource::Decl);
4112 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
4113 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
4116 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
4117 return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
4118 ConvertType(E->getType()));
4121 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
4122 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4123 AlignmentSource::Decl);
4127 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
4128 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4129 Slot.setExternallyDestructed();
4130 EmitAggExpr(E->getSubExpr(), Slot);
4131 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4132 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4133 AlignmentSource::Decl);
4137 CodeGenFunction::EmitLambdaLValue(const LambdaExpr *E) {
4138 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4139 EmitLambdaExpr(E, Slot);
4140 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4141 AlignmentSource::Decl);
4144 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
4145 RValue RV = EmitObjCMessageExpr(E);
4148 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4149 AlignmentSource::Decl);
4151 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4152 "Can't have a scalar return unless the return type is a "
4155 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4158 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
4160 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
4161 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4164 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
4165 const ObjCIvarDecl *Ivar) {
4166 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4169 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
4170 llvm::Value *BaseValue,
4171 const ObjCIvarDecl *Ivar,
4172 unsigned CVRQualifiers) {
4173 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4174 Ivar, CVRQualifiers);
4177 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
4178 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4179 llvm::Value *BaseValue = nullptr;
4180 const Expr *BaseExpr = E->getBase();
4181 Qualifiers BaseQuals;
4184 BaseValue = EmitScalarExpr(BaseExpr);
4185 ObjectTy = BaseExpr->getType()->getPointeeType();
4186 BaseQuals = ObjectTy.getQualifiers();
4188 LValue BaseLV = EmitLValue(BaseExpr);
4189 BaseValue = BaseLV.getPointer();
4190 ObjectTy = BaseExpr->getType();
4191 BaseQuals = ObjectTy.getQualifiers();
4195 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4196 BaseQuals.getCVRQualifiers());
4197 setObjCGCLValueClass(getContext(), E, LV);
4201 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
4202 // Can only get l-value for message expression returning aggregate type
4203 RValue RV = EmitAnyExprToTemp(E);
4204 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4205 AlignmentSource::Decl);
4208 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4209 const CallExpr *E, ReturnValueSlot ReturnValue,
4210 llvm::Value *Chain) {
4211 // Get the actual function type. The callee type will always be a pointer to
4212 // function type or a block pointer type.
4213 assert(CalleeType->isFunctionPointerType() &&
4214 "Call must have function pointer type!");
4216 const Decl *TargetDecl = OrigCallee.getAbstractInfo().getCalleeDecl();
4218 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
4219 // We can only guarantee that a function is called from the correct
4220 // context/function based on the appropriate target attributes,
4221 // so only check in the case where we have both always_inline and target
4222 // since otherwise we could be making a conditional call after a check for
4223 // the proper cpu features (and it won't cause code generation issues due to
4224 // function based code generation).
4225 if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
4226 TargetDecl->hasAttr<TargetAttr>())
4227 checkTargetFeatures(E, FD);
4229 CalleeType = getContext().getCanonicalType(CalleeType);
4231 const auto *FnType =
4232 cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
4234 CGCallee Callee = OrigCallee;
4236 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4237 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4238 if (llvm::Constant *PrefixSig =
4239 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
4240 SanitizerScope SanScope(this);
4241 llvm::Constant *FTRTTIConst =
4242 CGM.GetAddrOfRTTIDescriptor(QualType(FnType, 0), /*ForEH=*/true);
4243 llvm::Type *PrefixStructTyElems[] = {
4244 PrefixSig->getType(),
4245 FTRTTIConst->getType()
4247 llvm::StructType *PrefixStructTy = llvm::StructType::get(
4248 CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4250 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4252 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4253 CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4254 llvm::Value *CalleeSigPtr =
4255 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4256 llvm::Value *CalleeSig =
4257 Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4258 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4260 llvm::BasicBlock *Cont = createBasicBlock("cont");
4261 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4262 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4264 EmitBlock(TypeCheck);
4265 llvm::Value *CalleeRTTIPtr =
4266 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4267 llvm::Value *CalleeRTTI =
4268 Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4269 llvm::Value *CalleeRTTIMatch =
4270 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4271 llvm::Constant *StaticData[] = {
4272 EmitCheckSourceLocation(E->getLocStart()),
4273 EmitCheckTypeDescriptor(CalleeType)
4275 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4276 SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
4278 Builder.CreateBr(Cont);
4283 // If we are checking indirect calls and this call is indirect, check that the
4284 // function pointer is a member of the bit set for the function type.
4285 if (SanOpts.has(SanitizerKind::CFIICall) &&
4286 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4287 SanitizerScope SanScope(this);
4288 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4290 llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4291 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4293 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4294 llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4295 llvm::Value *TypeTest = Builder.CreateCall(
4296 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4298 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4299 llvm::Constant *StaticData[] = {
4300 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4301 EmitCheckSourceLocation(E->getLocStart()),
4302 EmitCheckTypeDescriptor(QualType(FnType, 0)),
4304 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4305 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4306 CastedCallee, StaticData);
4308 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4309 SanitizerHandler::CFICheckFail, StaticData,
4310 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4316 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
4317 CGM.getContext().VoidPtrTy);
4319 // C++17 requires that we evaluate arguments to a call using assignment syntax
4320 // right-to-left, and that we evaluate arguments to certain other operators
4321 // left-to-right. Note that we allow this to override the order dictated by
4322 // the calling convention on the MS ABI, which means that parameter
4323 // destruction order is not necessarily reverse construction order.
4324 // FIXME: Revisit this based on C++ committee response to unimplementability.
4325 EvaluationOrder Order = EvaluationOrder::Default;
4326 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4327 if (OCE->isAssignmentOp())
4328 Order = EvaluationOrder::ForceRightToLeft;
4330 switch (OCE->getOperator()) {
4332 case OO_GreaterGreater:
4337 Order = EvaluationOrder::ForceLeftToRight;
4345 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4346 E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4348 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
4349 Args, FnType, /*isChainCall=*/Chain);
4352 // If the expression that denotes the called function has a type
4353 // that does not include a prototype, [the default argument
4354 // promotions are performed]. If the number of arguments does not
4355 // equal the number of parameters, the behavior is undefined. If
4356 // the function is defined with a type that includes a prototype,
4357 // and either the prototype ends with an ellipsis (, ...) or the
4358 // types of the arguments after promotion are not compatible with
4359 // the types of the parameters, the behavior is undefined. If the
4360 // function is defined with a type that does not include a
4361 // prototype, and the types of the arguments after promotion are
4362 // not compatible with those of the parameters after promotion,
4363 // the behavior is undefined [except in some trivial cases].
4364 // That is, in the general case, we should assume that a call
4365 // through an unprototyped function type works like a *non-variadic*
4366 // call. The way we make this work is to cast to the exact type
4367 // of the promoted arguments.
4369 // Chain calls use this same code path to add the invisible chain parameter
4370 // to the function type.
4371 if (isa<FunctionNoProtoType>(FnType) || Chain) {
4372 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4373 CalleeTy = CalleeTy->getPointerTo();
4375 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4376 CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
4377 Callee.setFunctionPointer(CalleePtr);
4380 return EmitCall(FnInfo, Callee, ReturnValue, Args);
4383 LValue CodeGenFunction::
4384 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
4385 Address BaseAddr = Address::invalid();
4386 if (E->getOpcode() == BO_PtrMemI) {
4387 BaseAddr = EmitPointerWithAlignment(E->getLHS());
4389 BaseAddr = EmitLValue(E->getLHS()).getAddress();
4392 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4394 const MemberPointerType *MPT
4395 = E->getRHS()->getType()->getAs<MemberPointerType>();
4397 AlignmentSource AlignSource;
4398 Address MemberAddr =
4399 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT,
4402 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), AlignSource);
4405 /// Given the address of a temporary variable, produce an r-value of
4407 RValue CodeGenFunction::convertTempToRValue(Address addr,
4409 SourceLocation loc) {
4410 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
4411 switch (getEvaluationKind(type)) {
4413 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4415 return lvalue.asAggregateRValue();
4417 return RValue::get(EmitLoadOfScalar(lvalue, loc));
4419 llvm_unreachable("bad evaluation kind");
4422 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4423 assert(Val->getType()->isFPOrFPVectorTy());
4424 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4427 llvm::MDBuilder MDHelper(getLLVMContext());
4428 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
4430 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
4434 struct LValueOrRValue {
4440 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
4441 const PseudoObjectExpr *E,
4443 AggValueSlot slot) {
4444 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
4446 // Find the result expression, if any.
4447 const Expr *resultExpr = E->getResultExpr();
4448 LValueOrRValue result;
4450 for (PseudoObjectExpr::const_semantics_iterator
4451 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
4452 const Expr *semantic = *i;
4454 // If this semantic expression is an opaque value, bind it
4455 // to the result of its source expression.
4456 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
4458 // If this is the result expression, we may need to evaluate
4459 // directly into the slot.
4460 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
4462 if (ov == resultExpr && ov->isRValue() && !forLValue &&
4463 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
4464 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
4466 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
4467 AlignmentSource::Decl);
4468 opaqueData = OVMA::bind(CGF, ov, LV);
4469 result.RV = slot.asRValue();
4471 // Otherwise, emit as normal.
4473 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
4475 // If this is the result, also evaluate the result now.
4476 if (ov == resultExpr) {
4478 result.LV = CGF.EmitLValue(ov);
4480 result.RV = CGF.EmitAnyExpr(ov, slot);
4484 opaques.push_back(opaqueData);
4486 // Otherwise, if the expression is the result, evaluate it
4487 // and remember the result.
4488 } else if (semantic == resultExpr) {
4490 result.LV = CGF.EmitLValue(semantic);
4492 result.RV = CGF.EmitAnyExpr(semantic, slot);
4494 // Otherwise, evaluate the expression in an ignored context.
4496 CGF.EmitIgnoredExpr(semantic);
4500 // Unbind all the opaques now.
4501 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
4502 opaques[i].unbind(CGF);
4507 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
4508 AggValueSlot slot) {
4509 return emitPseudoObjectExpr(*this, E, false, slot).RV;
4512 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
4513 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;