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 llvm::Value *ArraySize,
66 bool CastToDefaultAddrSpace) {
67 auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
68 Alloca->setAlignment(Align.getQuantity());
69 llvm::Value *V = Alloca;
70 // Alloca always returns a pointer in alloca address space, which may
71 // be different from the type defined by the language. For example,
72 // in C++ the auto variables are in the default address space. Therefore
73 // cast alloca to the default address space when necessary.
74 if (CastToDefaultAddrSpace && getASTAllocaAddressSpace() != LangAS::Default) {
75 auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
76 auto CurIP = Builder.saveIP();
77 Builder.SetInsertPoint(AllocaInsertPt);
78 V = getTargetHooks().performAddrSpaceCast(
79 *this, V, getASTAllocaAddressSpace(), LangAS::Default,
80 Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
81 Builder.restoreIP(CurIP);
84 return Address(V, Align);
87 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
88 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
89 /// insertion point of the builder.
90 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
92 llvm::Value *ArraySize) {
94 return Builder.CreateAlloca(Ty, ArraySize, Name);
95 return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
96 ArraySize, Name, AllocaInsertPt);
99 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
100 /// default alignment of the corresponding LLVM type, which is *not*
101 /// guaranteed to be related in any way to the expected alignment of
102 /// an AST type that might have been lowered to Ty.
103 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
106 CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
107 return CreateTempAlloca(Ty, Align, Name);
110 void CodeGenFunction::InitTempAlloca(Address Var, llvm::Value *Init) {
111 assert(isa<llvm::AllocaInst>(Var.getPointer()));
112 auto *Store = new llvm::StoreInst(Init, Var.getPointer());
113 Store->setAlignment(Var.getAlignment().getQuantity());
114 llvm::BasicBlock *Block = AllocaInsertPt->getParent();
115 Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
118 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
119 CharUnits Align = getContext().getTypeAlignInChars(Ty);
120 return CreateTempAlloca(ConvertType(Ty), Align, Name);
123 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name,
124 bool CastToDefaultAddrSpace) {
125 // FIXME: Should we prefer the preferred type alignment here?
126 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name,
127 CastToDefaultAddrSpace);
130 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
132 bool CastToDefaultAddrSpace) {
133 return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name, nullptr,
134 CastToDefaultAddrSpace);
137 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
138 /// expression and compare the result against zero, returning an Int1Ty value.
139 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
140 PGO.setCurrentStmt(E);
141 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
142 llvm::Value *MemPtr = EmitScalarExpr(E);
143 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
146 QualType BoolTy = getContext().BoolTy;
147 SourceLocation Loc = E->getExprLoc();
148 if (!E->getType()->isAnyComplexType())
149 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
151 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
155 /// EmitIgnoredExpr - Emit code to compute the specified expression,
156 /// ignoring the result.
157 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
159 return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
161 // Just emit it as an l-value and drop the result.
165 /// EmitAnyExpr - Emit code to compute the specified expression which
166 /// can have any type. The result is returned as an RValue struct.
167 /// If this is an aggregate expression, AggSlot indicates where the
168 /// result should be returned.
169 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
170 AggValueSlot aggSlot,
172 switch (getEvaluationKind(E->getType())) {
174 return RValue::get(EmitScalarExpr(E, ignoreResult));
176 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
178 if (!ignoreResult && aggSlot.isIgnored())
179 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
180 EmitAggExpr(E, aggSlot);
181 return aggSlot.asRValue();
183 llvm_unreachable("bad evaluation kind");
186 /// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
187 /// always be accessible even if no aggregate location is provided.
188 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
189 AggValueSlot AggSlot = AggValueSlot::ignored();
191 if (hasAggregateEvaluationKind(E->getType()))
192 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
193 return EmitAnyExpr(E, AggSlot);
196 /// EmitAnyExprToMem - Evaluate an expression into a given memory
198 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
202 // FIXME: This function should take an LValue as an argument.
203 switch (getEvaluationKind(E->getType())) {
205 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
209 case TEK_Aggregate: {
210 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
211 AggValueSlot::IsDestructed_t(IsInit),
212 AggValueSlot::DoesNotNeedGCBarriers,
213 AggValueSlot::IsAliased_t(!IsInit)));
218 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
219 LValue LV = MakeAddrLValue(Location, E->getType());
220 EmitStoreThroughLValue(RV, LV);
224 llvm_unreachable("bad evaluation kind");
228 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
229 const Expr *E, Address ReferenceTemporary) {
230 // Objective-C++ ARC:
231 // If we are binding a reference to a temporary that has ownership, we
232 // need to perform retain/release operations on the temporary.
234 // FIXME: This should be looking at E, not M.
235 if (auto Lifetime = M->getType().getObjCLifetime()) {
237 case Qualifiers::OCL_None:
238 case Qualifiers::OCL_ExplicitNone:
239 // Carry on to normal cleanup handling.
242 case Qualifiers::OCL_Autoreleasing:
243 // Nothing to do; cleaned up by an autorelease pool.
246 case Qualifiers::OCL_Strong:
247 case Qualifiers::OCL_Weak:
248 switch (StorageDuration Duration = M->getStorageDuration()) {
250 // Note: we intentionally do not register a cleanup to release
251 // the object on program termination.
255 // FIXME: We should probably register a cleanup in this case.
259 case SD_FullExpression:
260 CodeGenFunction::Destroyer *Destroy;
261 CleanupKind CleanupKind;
262 if (Lifetime == Qualifiers::OCL_Strong) {
263 const ValueDecl *VD = M->getExtendingDecl();
265 VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
266 CleanupKind = CGF.getARCCleanupKind();
267 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
268 : &CodeGenFunction::destroyARCStrongImprecise;
270 // __weak objects always get EH cleanups; otherwise, exceptions
271 // could cause really nasty crashes instead of mere leaks.
272 CleanupKind = NormalAndEHCleanup;
273 Destroy = &CodeGenFunction::destroyARCWeak;
275 if (Duration == SD_FullExpression)
276 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
277 M->getType(), *Destroy,
278 CleanupKind & EHCleanup);
280 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
282 *Destroy, CleanupKind & EHCleanup);
286 llvm_unreachable("temporary cannot have dynamic storage duration");
288 llvm_unreachable("unknown storage duration");
292 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
293 if (const RecordType *RT =
294 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
295 // Get the destructor for the reference temporary.
296 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
297 if (!ClassDecl->hasTrivialDestructor())
298 ReferenceTemporaryDtor = ClassDecl->getDestructor();
301 if (!ReferenceTemporaryDtor)
304 // Call the destructor for the temporary.
305 switch (M->getStorageDuration()) {
308 llvm::Constant *CleanupFn;
309 llvm::Constant *CleanupArg;
310 if (E->getType()->isArrayType()) {
311 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
312 ReferenceTemporary, E->getType(),
313 CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
314 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
315 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
317 CleanupFn = CGF.CGM.getAddrOfCXXStructor(ReferenceTemporaryDtor,
318 StructorType::Complete);
319 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
321 CGF.CGM.getCXXABI().registerGlobalDtor(
322 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
326 case SD_FullExpression:
327 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
328 CodeGenFunction::destroyCXXObject,
329 CGF.getLangOpts().Exceptions);
333 CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
334 ReferenceTemporary, E->getType(),
335 CodeGenFunction::destroyCXXObject,
336 CGF.getLangOpts().Exceptions);
340 llvm_unreachable("temporary cannot have dynamic storage duration");
344 static Address createReferenceTemporary(CodeGenFunction &CGF,
345 const MaterializeTemporaryExpr *M,
347 auto &TCG = CGF.getTargetHooks();
348 switch (M->getStorageDuration()) {
349 case SD_FullExpression:
351 // If we have a constant temporary array or record try to promote it into a
352 // constant global under the same rules a normal constant would've been
353 // promoted. This is easier on the optimizer and generally emits fewer
355 QualType Ty = Inner->getType();
356 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
357 (Ty->isArrayType() || Ty->isRecordType()) &&
358 CGF.CGM.isTypeConstant(Ty, true))
359 if (llvm::Constant *Init = CGF.CGM.EmitConstantExpr(Inner, Ty, &CGF)) {
360 if (auto AddrSpace = CGF.getTarget().getConstantAddressSpace()) {
361 auto AS = AddrSpace.getValue();
362 auto *GV = new llvm::GlobalVariable(
363 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
364 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
365 llvm::GlobalValue::NotThreadLocal,
366 CGF.getContext().getTargetAddressSpace(AS));
367 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
368 GV->setAlignment(alignment.getQuantity());
369 llvm::Constant *C = GV;
370 if (AS != LangAS::Default)
371 C = TCG.performAddrSpaceCast(
372 CGF.CGM, GV, AS, LangAS::Default,
373 GV->getValueType()->getPointerTo(
374 CGF.getContext().getTargetAddressSpace(LangAS::Default)));
375 // FIXME: Should we put the new global into a COMDAT?
376 return Address(C, alignment);
379 return CGF.CreateMemTemp(Ty, "ref.tmp");
383 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
386 llvm_unreachable("temporary can't have dynamic storage duration");
388 llvm_unreachable("unknown storage duration");
391 LValue CodeGenFunction::
392 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
393 const Expr *E = M->GetTemporaryExpr();
395 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
396 // as that will cause the lifetime adjustment to be lost for ARC
397 auto ownership = M->getType().getObjCLifetime();
398 if (ownership != Qualifiers::OCL_None &&
399 ownership != Qualifiers::OCL_ExplicitNone) {
400 Address Object = createReferenceTemporary(*this, M, E);
401 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
402 Object = Address(llvm::ConstantExpr::getBitCast(Var,
403 ConvertTypeForMem(E->getType())
404 ->getPointerTo(Object.getAddressSpace())),
405 Object.getAlignment());
407 // createReferenceTemporary will promote the temporary to a global with a
408 // constant initializer if it can. It can only do this to a value of
409 // ARC-manageable type if the value is global and therefore "immune" to
410 // ref-counting operations. Therefore we have no need to emit either a
411 // dynamic initialization or a cleanup and we can just return the address
413 if (Var->hasInitializer())
414 return MakeAddrLValue(Object, M->getType(),
415 LValueBaseInfo(AlignmentSource::Decl, false));
417 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
419 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
420 LValueBaseInfo(AlignmentSource::Decl,
423 switch (getEvaluationKind(E->getType())) {
424 default: llvm_unreachable("expected scalar or aggregate expression");
426 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
428 case TEK_Aggregate: {
429 EmitAggExpr(E, AggValueSlot::forAddr(Object,
430 E->getType().getQualifiers(),
431 AggValueSlot::IsDestructed,
432 AggValueSlot::DoesNotNeedGCBarriers,
433 AggValueSlot::IsNotAliased));
438 pushTemporaryCleanup(*this, M, E, Object);
442 SmallVector<const Expr *, 2> CommaLHSs;
443 SmallVector<SubobjectAdjustment, 2> Adjustments;
444 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
446 for (const auto &Ignored : CommaLHSs)
447 EmitIgnoredExpr(Ignored);
449 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
450 if (opaque->getType()->isRecordType()) {
451 assert(Adjustments.empty());
452 return EmitOpaqueValueLValue(opaque);
456 // Create and initialize the reference temporary.
457 Address Object = createReferenceTemporary(*this, M, E);
458 if (auto *Var = dyn_cast<llvm::GlobalVariable>(
459 Object.getPointer()->stripPointerCasts())) {
460 Object = Address(llvm::ConstantExpr::getBitCast(
461 cast<llvm::Constant>(Object.getPointer()),
462 ConvertTypeForMem(E->getType())->getPointerTo()),
463 Object.getAlignment());
464 // If the temporary is a global and has a constant initializer or is a
465 // constant temporary that we promoted to a global, we may have already
467 if (!Var->hasInitializer()) {
468 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
469 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
472 switch (M->getStorageDuration()) {
474 case SD_FullExpression:
475 if (auto *Size = EmitLifetimeStart(
476 CGM.getDataLayout().getTypeAllocSize(Object.getElementType()),
477 Object.getPointer())) {
478 if (M->getStorageDuration() == SD_Automatic)
479 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
482 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Object,
489 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
491 pushTemporaryCleanup(*this, M, E, Object);
493 // Perform derived-to-base casts and/or field accesses, to get from the
494 // temporary object we created (and, potentially, for which we extended
495 // the lifetime) to the subobject we're binding the reference to.
496 for (unsigned I = Adjustments.size(); I != 0; --I) {
497 SubobjectAdjustment &Adjustment = Adjustments[I-1];
498 switch (Adjustment.Kind) {
499 case SubobjectAdjustment::DerivedToBaseAdjustment:
501 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
502 Adjustment.DerivedToBase.BasePath->path_begin(),
503 Adjustment.DerivedToBase.BasePath->path_end(),
504 /*NullCheckValue=*/ false, E->getExprLoc());
507 case SubobjectAdjustment::FieldAdjustment: {
508 LValue LV = MakeAddrLValue(Object, E->getType(),
509 LValueBaseInfo(AlignmentSource::Decl, false));
510 LV = EmitLValueForField(LV, Adjustment.Field);
511 assert(LV.isSimple() &&
512 "materialized temporary field is not a simple lvalue");
513 Object = LV.getAddress();
517 case SubobjectAdjustment::MemberPointerAdjustment: {
518 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
519 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
526 return MakeAddrLValue(Object, M->getType(),
527 LValueBaseInfo(AlignmentSource::Decl, false));
531 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
532 // Emit the expression as an lvalue.
533 LValue LV = EmitLValue(E);
534 assert(LV.isSimple());
535 llvm::Value *Value = LV.getPointer();
537 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
538 // C++11 [dcl.ref]p5 (as amended by core issue 453):
539 // If a glvalue to which a reference is directly bound designates neither
540 // an existing object or function of an appropriate type nor a region of
541 // storage of suitable size and alignment to contain an object of the
542 // reference's type, the behavior is undefined.
543 QualType Ty = E->getType();
544 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
547 return RValue::get(Value);
551 /// getAccessedFieldNo - Given an encoded value and a result number, return the
552 /// input field number being accessed.
553 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
554 const llvm::Constant *Elts) {
555 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
559 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
560 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
562 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
563 llvm::Value *K47 = Builder.getInt64(47);
564 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
565 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
566 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
567 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
568 return Builder.CreateMul(B1, KMul);
571 bool CodeGenFunction::sanitizePerformTypeCheck() const {
572 return SanOpts.has(SanitizerKind::Null) |
573 SanOpts.has(SanitizerKind::Alignment) |
574 SanOpts.has(SanitizerKind::ObjectSize) |
575 SanOpts.has(SanitizerKind::Vptr);
578 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
579 llvm::Value *Ptr, QualType Ty,
581 SanitizerSet SkippedChecks) {
582 if (!sanitizePerformTypeCheck())
585 // Don't check pointers outside the default address space. The null check
586 // isn't correct, the object-size check isn't supported by LLVM, and we can't
587 // communicate the addresses to the runtime handler for the vptr check.
588 if (Ptr->getType()->getPointerAddressSpace())
591 // Don't check pointers to volatile data. The behavior here is implementation-
593 if (Ty.isVolatileQualified())
596 SanitizerScope SanScope(this);
598 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
599 llvm::BasicBlock *Done = nullptr;
601 // Quickly determine whether we have a pointer to an alloca. It's possible
602 // to skip null checks, and some alignment checks, for these pointers. This
603 // can reduce compile-time significantly.
605 dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCastsNoFollowAliases());
607 bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
608 TCK == TCK_UpcastToVirtualBase;
609 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
610 !SkippedChecks.has(SanitizerKind::Null) && !PtrToAlloca) {
611 // The glvalue must not be an empty glvalue.
612 llvm::Value *IsNonNull = Builder.CreateIsNotNull(Ptr);
614 // The IR builder can constant-fold the null check if the pointer points to
617 IsNonNull == llvm::ConstantInt::getTrue(getLLVMContext());
619 // Skip the null check if the pointer is known to be non-null.
621 if (AllowNullPointers) {
622 // When performing pointer casts, it's OK if the value is null.
623 // Skip the remaining checks in that case.
624 Done = createBasicBlock("null");
625 llvm::BasicBlock *Rest = createBasicBlock("not.null");
626 Builder.CreateCondBr(IsNonNull, Rest, Done);
629 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
634 if (SanOpts.has(SanitizerKind::ObjectSize) &&
635 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
636 !Ty->isIncompleteType()) {
637 uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
639 // The glvalue must refer to a large enough storage region.
640 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
642 // FIXME: Get object address space
643 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
644 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
645 llvm::Value *Min = Builder.getFalse();
646 llvm::Value *NullIsUnknown = Builder.getFalse();
647 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
648 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
649 Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown}),
650 llvm::ConstantInt::get(IntPtrTy, Size));
651 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
654 uint64_t AlignVal = 0;
656 if (SanOpts.has(SanitizerKind::Alignment) &&
657 !SkippedChecks.has(SanitizerKind::Alignment)) {
658 AlignVal = Alignment.getQuantity();
659 if (!Ty->isIncompleteType() && !AlignVal)
660 AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
662 // The glvalue must be suitably aligned.
664 (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
666 Builder.CreateAnd(Builder.CreatePtrToInt(Ptr, IntPtrTy),
667 llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
668 llvm::Value *Aligned =
669 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
670 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
674 if (Checks.size() > 0) {
675 // Make sure we're not losing information. Alignment needs to be a power of
677 assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
678 llvm::Constant *StaticData[] = {
679 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
680 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
681 llvm::ConstantInt::get(Int8Ty, TCK)};
682 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData, Ptr);
685 // If possible, check that the vptr indicates that there is a subobject of
686 // type Ty at offset zero within this object.
688 // C++11 [basic.life]p5,6:
689 // [For storage which does not refer to an object within its lifetime]
690 // The program has undefined behavior if:
691 // -- the [pointer or glvalue] is used to access a non-static data member
692 // or call a non-static member function
693 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
694 if (SanOpts.has(SanitizerKind::Vptr) &&
695 !SkippedChecks.has(SanitizerKind::Vptr) &&
696 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
697 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
698 TCK == TCK_UpcastToVirtualBase) &&
699 RD && RD->hasDefinition() && RD->isDynamicClass()) {
700 // Compute a hash of the mangled name of the type.
702 // FIXME: This is not guaranteed to be deterministic! Move to a
703 // fingerprinting mechanism once LLVM provides one. For the time
704 // being the implementation happens to be deterministic.
705 SmallString<64> MangledName;
706 llvm::raw_svector_ostream Out(MangledName);
707 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
710 // Blacklist based on the mangled type.
711 if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
713 llvm::hash_code TypeHash = hash_value(Out.str());
715 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
716 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
717 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
718 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
719 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
720 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
722 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
723 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
725 // Look the hash up in our cache.
726 const int CacheSize = 128;
727 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
728 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
729 "__ubsan_vptr_type_cache");
730 llvm::Value *Slot = Builder.CreateAnd(Hash,
731 llvm::ConstantInt::get(IntPtrTy,
733 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
734 llvm::Value *CacheVal =
735 Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
738 // If the hash isn't in the cache, call a runtime handler to perform the
739 // hard work of checking whether the vptr is for an object of the right
740 // type. This will either fill in the cache and return, or produce a
742 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
743 llvm::Constant *StaticData[] = {
744 EmitCheckSourceLocation(Loc),
745 EmitCheckTypeDescriptor(Ty),
746 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
747 llvm::ConstantInt::get(Int8Ty, TCK)
749 llvm::Value *DynamicData[] = { Ptr, Hash };
750 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
751 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
757 Builder.CreateBr(Done);
762 /// Determine whether this expression refers to a flexible array member in a
763 /// struct. We disable array bounds checks for such members.
764 static bool isFlexibleArrayMemberExpr(const Expr *E) {
765 // For compatibility with existing code, we treat arrays of length 0 or
766 // 1 as flexible array members.
767 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
768 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
769 if (CAT->getSize().ugt(1))
771 } else if (!isa<IncompleteArrayType>(AT))
774 E = E->IgnoreParens();
776 // A flexible array member must be the last member in the class.
777 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
778 // FIXME: If the base type of the member expr is not FD->getParent(),
779 // this should not be treated as a flexible array member access.
780 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
781 RecordDecl::field_iterator FI(
782 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
783 return ++FI == FD->getParent()->field_end();
785 } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
786 return IRE->getDecl()->getNextIvar() == nullptr;
792 /// If Base is known to point to the start of an array, return the length of
793 /// that array. Return 0 if the length cannot be determined.
794 static llvm::Value *getArrayIndexingBound(
795 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
796 // For the vector indexing extension, the bound is the number of elements.
797 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
798 IndexedType = Base->getType();
799 return CGF.Builder.getInt32(VT->getNumElements());
802 Base = Base->IgnoreParens();
804 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
805 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
806 !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
807 IndexedType = CE->getSubExpr()->getType();
808 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
809 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
810 return CGF.Builder.getInt(CAT->getSize());
811 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
812 return CGF.getVLASize(VAT).first;
819 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
820 llvm::Value *Index, QualType IndexType,
822 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
823 "should not be called unless adding bounds checks");
824 SanitizerScope SanScope(this);
826 QualType IndexedType;
827 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
831 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
832 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
833 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
835 llvm::Constant *StaticData[] = {
836 EmitCheckSourceLocation(E->getExprLoc()),
837 EmitCheckTypeDescriptor(IndexedType),
838 EmitCheckTypeDescriptor(IndexType)
840 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
841 : Builder.CreateICmpULE(IndexVal, BoundVal);
842 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
843 SanitizerHandler::OutOfBounds, StaticData, Index);
847 CodeGenFunction::ComplexPairTy CodeGenFunction::
848 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
849 bool isInc, bool isPre) {
850 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
852 llvm::Value *NextVal;
853 if (isa<llvm::IntegerType>(InVal.first->getType())) {
854 uint64_t AmountVal = isInc ? 1 : -1;
855 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
857 // Add the inc/dec to the real part.
858 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
860 QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
861 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
864 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
866 // Add the inc/dec to the real part.
867 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
870 ComplexPairTy IncVal(NextVal, InVal.second);
872 // Store the updated result through the lvalue.
873 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
875 // If this is a postinc, return the value read from memory, otherwise use the
877 return isPre ? IncVal : InVal;
880 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
881 CodeGenFunction *CGF) {
882 // Bind VLAs in the cast type.
883 if (CGF && E->getType()->isVariablyModifiedType())
884 CGF->EmitVariablyModifiedType(E->getType());
886 if (CGDebugInfo *DI = getModuleDebugInfo())
887 DI->EmitExplicitCastType(E->getType());
890 //===----------------------------------------------------------------------===//
891 // LValue Expression Emission
892 //===----------------------------------------------------------------------===//
894 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
895 /// derive a more accurate bound on the alignment of the pointer.
896 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
897 LValueBaseInfo *BaseInfo) {
898 // We allow this with ObjC object pointers because of fragile ABIs.
899 assert(E->getType()->isPointerType() ||
900 E->getType()->isObjCObjectPointerType());
901 E = E->IgnoreParens();
904 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
905 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
906 CGM.EmitExplicitCastExprType(ECE, this);
908 switch (CE->getCastKind()) {
909 // Non-converting casts (but not C's implicit conversion from void*).
912 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
913 if (PtrTy->getPointeeType()->isVoidType())
916 LValueBaseInfo InnerInfo;
917 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), &InnerInfo);
918 if (BaseInfo) *BaseInfo = InnerInfo;
920 // If this is an explicit bitcast, and the source l-value is
921 // opaque, honor the alignment of the casted-to type.
922 if (isa<ExplicitCastExpr>(CE) &&
923 InnerInfo.getAlignmentSource() != AlignmentSource::Decl) {
924 LValueBaseInfo ExpInfo;
925 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
928 BaseInfo->mergeForCast(ExpInfo);
929 Addr = Address(Addr.getPointer(), Align);
932 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
933 CE->getCastKind() == CK_BitCast) {
934 if (auto PT = E->getType()->getAs<PointerType>())
935 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
937 CodeGenFunction::CFITCK_UnrelatedCast,
941 return Builder.CreateBitCast(Addr, ConvertType(E->getType()));
945 // Array-to-pointer decay.
946 case CK_ArrayToPointerDecay:
947 return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo);
949 // Derived-to-base conversions.
950 case CK_UncheckedDerivedToBase:
951 case CK_DerivedToBase: {
952 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
953 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
954 return GetAddressOfBaseClass(Addr, Derived,
955 CE->path_begin(), CE->path_end(),
956 ShouldNullCheckClassCastValue(CE),
960 // TODO: Is there any reason to treat base-to-derived conversions
968 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
969 if (UO->getOpcode() == UO_AddrOf) {
970 LValue LV = EmitLValue(UO->getSubExpr());
971 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
972 return LV.getAddress();
976 // TODO: conditional operators, comma.
978 // Otherwise, use the alignment of the type.
979 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo);
980 return Address(EmitScalarExpr(E), Align);
983 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
984 if (Ty->isVoidType())
985 return RValue::get(nullptr);
987 switch (getEvaluationKind(Ty)) {
990 ConvertType(Ty->castAs<ComplexType>()->getElementType());
991 llvm::Value *U = llvm::UndefValue::get(EltTy);
992 return RValue::getComplex(std::make_pair(U, U));
995 // If this is a use of an undefined aggregate type, the aggregate must have an
996 // identifiable address. Just because the contents of the value are undefined
997 // doesn't mean that the address can't be taken and compared.
998 case TEK_Aggregate: {
999 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1000 return RValue::getAggregate(DestPtr);
1004 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1006 llvm_unreachable("bad evaluation kind");
1009 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
1011 ErrorUnsupported(E, Name);
1012 return GetUndefRValue(E->getType());
1015 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
1017 ErrorUnsupported(E, Name);
1018 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1019 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1023 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
1024 const Expr *Base = Obj;
1025 while (!isa<CXXThisExpr>(Base)) {
1026 // The result of a dynamic_cast can be null.
1027 if (isa<CXXDynamicCastExpr>(Base))
1030 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1031 Base = CE->getSubExpr();
1032 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1033 Base = PE->getSubExpr();
1034 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1035 if (UO->getOpcode() == UO_Extension)
1036 Base = UO->getSubExpr();
1046 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1048 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1049 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1052 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1053 SanitizerSet SkippedChecks;
1054 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1055 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1057 SkippedChecks.set(SanitizerKind::Alignment, true);
1058 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1059 SkippedChecks.set(SanitizerKind::Null, true);
1061 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
1062 E->getType(), LV.getAlignment(), SkippedChecks);
1067 /// EmitLValue - Emit code to compute a designator that specifies the location
1068 /// of the expression.
1070 /// This can return one of two things: a simple address or a bitfield reference.
1071 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1072 /// an LLVM pointer type.
1074 /// If this returns a bitfield reference, nothing about the pointee type of the
1075 /// LLVM value is known: For example, it may not be a pointer to an integer.
1077 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1078 /// this method guarantees that the returned pointer type will point to an LLVM
1079 /// type of the same size of the lvalue's type. If the lvalue has a variable
1080 /// length type, this is not possible.
1082 LValue CodeGenFunction::EmitLValue(const Expr *E) {
1083 ApplyDebugLocation DL(*this, E);
1084 switch (E->getStmtClass()) {
1085 default: return EmitUnsupportedLValue(E, "l-value expression");
1087 case Expr::ObjCPropertyRefExprClass:
1088 llvm_unreachable("cannot emit a property reference directly");
1090 case Expr::ObjCSelectorExprClass:
1091 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1092 case Expr::ObjCIsaExprClass:
1093 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1094 case Expr::BinaryOperatorClass:
1095 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1096 case Expr::CompoundAssignOperatorClass: {
1097 QualType Ty = E->getType();
1098 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1099 Ty = AT->getValueType();
1100 if (!Ty->isAnyComplexType())
1101 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1102 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1104 case Expr::CallExprClass:
1105 case Expr::CXXMemberCallExprClass:
1106 case Expr::CXXOperatorCallExprClass:
1107 case Expr::UserDefinedLiteralClass:
1108 return EmitCallExprLValue(cast<CallExpr>(E));
1109 case Expr::VAArgExprClass:
1110 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1111 case Expr::DeclRefExprClass:
1112 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1113 case Expr::ParenExprClass:
1114 return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1115 case Expr::GenericSelectionExprClass:
1116 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1117 case Expr::PredefinedExprClass:
1118 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1119 case Expr::StringLiteralClass:
1120 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1121 case Expr::ObjCEncodeExprClass:
1122 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1123 case Expr::PseudoObjectExprClass:
1124 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1125 case Expr::InitListExprClass:
1126 return EmitInitListLValue(cast<InitListExpr>(E));
1127 case Expr::CXXTemporaryObjectExprClass:
1128 case Expr::CXXConstructExprClass:
1129 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1130 case Expr::CXXBindTemporaryExprClass:
1131 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1132 case Expr::CXXUuidofExprClass:
1133 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1134 case Expr::LambdaExprClass:
1135 return EmitLambdaLValue(cast<LambdaExpr>(E));
1137 case Expr::ExprWithCleanupsClass: {
1138 const auto *cleanups = cast<ExprWithCleanups>(E);
1139 enterFullExpression(cleanups);
1140 RunCleanupsScope Scope(*this);
1141 LValue LV = EmitLValue(cleanups->getSubExpr());
1142 if (LV.isSimple()) {
1143 // Defend against branches out of gnu statement expressions surrounded by
1145 llvm::Value *V = LV.getPointer();
1146 Scope.ForceCleanup({&V});
1147 return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1148 getContext(), LV.getBaseInfo(),
1151 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1152 // bitfield lvalue or some other non-simple lvalue?
1156 case Expr::CXXDefaultArgExprClass:
1157 return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1158 case Expr::CXXDefaultInitExprClass: {
1159 CXXDefaultInitExprScope Scope(*this);
1160 return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1162 case Expr::CXXTypeidExprClass:
1163 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1165 case Expr::ObjCMessageExprClass:
1166 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1167 case Expr::ObjCIvarRefExprClass:
1168 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1169 case Expr::StmtExprClass:
1170 return EmitStmtExprLValue(cast<StmtExpr>(E));
1171 case Expr::UnaryOperatorClass:
1172 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1173 case Expr::ArraySubscriptExprClass:
1174 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1175 case Expr::OMPArraySectionExprClass:
1176 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1177 case Expr::ExtVectorElementExprClass:
1178 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1179 case Expr::MemberExprClass:
1180 return EmitMemberExpr(cast<MemberExpr>(E));
1181 case Expr::CompoundLiteralExprClass:
1182 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1183 case Expr::ConditionalOperatorClass:
1184 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1185 case Expr::BinaryConditionalOperatorClass:
1186 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1187 case Expr::ChooseExprClass:
1188 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1189 case Expr::OpaqueValueExprClass:
1190 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1191 case Expr::SubstNonTypeTemplateParmExprClass:
1192 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1193 case Expr::ImplicitCastExprClass:
1194 case Expr::CStyleCastExprClass:
1195 case Expr::CXXFunctionalCastExprClass:
1196 case Expr::CXXStaticCastExprClass:
1197 case Expr::CXXDynamicCastExprClass:
1198 case Expr::CXXReinterpretCastExprClass:
1199 case Expr::CXXConstCastExprClass:
1200 case Expr::ObjCBridgedCastExprClass:
1201 return EmitCastLValue(cast<CastExpr>(E));
1203 case Expr::MaterializeTemporaryExprClass:
1204 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1206 case Expr::CoawaitExprClass:
1207 return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1208 case Expr::CoyieldExprClass:
1209 return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1213 /// Given an object of the given canonical type, can we safely copy a
1214 /// value out of it based on its initializer?
1215 static bool isConstantEmittableObjectType(QualType type) {
1216 assert(type.isCanonical());
1217 assert(!type->isReferenceType());
1219 // Must be const-qualified but non-volatile.
1220 Qualifiers qs = type.getLocalQualifiers();
1221 if (!qs.hasConst() || qs.hasVolatile()) return false;
1223 // Otherwise, all object types satisfy this except C++ classes with
1224 // mutable subobjects or non-trivial copy/destroy behavior.
1225 if (const auto *RT = dyn_cast<RecordType>(type))
1226 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1227 if (RD->hasMutableFields() || !RD->isTrivial())
1233 /// Can we constant-emit a load of a reference to a variable of the
1234 /// given type? This is different from predicates like
1235 /// Decl::isUsableInConstantExpressions because we do want it to apply
1236 /// in situations that don't necessarily satisfy the language's rules
1237 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1238 /// to do this with const float variables even if those variables
1239 /// aren't marked 'constexpr'.
1240 enum ConstantEmissionKind {
1242 CEK_AsReferenceOnly,
1243 CEK_AsValueOrReference,
1246 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1247 type = type.getCanonicalType();
1248 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1249 if (isConstantEmittableObjectType(ref->getPointeeType()))
1250 return CEK_AsValueOrReference;
1251 return CEK_AsReferenceOnly;
1253 if (isConstantEmittableObjectType(type))
1254 return CEK_AsValueOnly;
1258 /// Try to emit a reference to the given value without producing it as
1259 /// an l-value. This is actually more than an optimization: we can't
1260 /// produce an l-value for variables that we never actually captured
1261 /// in a block or lambda, which means const int variables or constexpr
1262 /// literals or similar.
1263 CodeGenFunction::ConstantEmission
1264 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1265 ValueDecl *value = refExpr->getDecl();
1267 // The value needs to be an enum constant or a constant variable.
1268 ConstantEmissionKind CEK;
1269 if (isa<ParmVarDecl>(value)) {
1271 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1272 CEK = checkVarTypeForConstantEmission(var->getType());
1273 } else if (isa<EnumConstantDecl>(value)) {
1274 CEK = CEK_AsValueOnly;
1278 if (CEK == CEK_None) return ConstantEmission();
1280 Expr::EvalResult result;
1281 bool resultIsReference;
1282 QualType resultType;
1284 // It's best to evaluate all the way as an r-value if that's permitted.
1285 if (CEK != CEK_AsReferenceOnly &&
1286 refExpr->EvaluateAsRValue(result, getContext())) {
1287 resultIsReference = false;
1288 resultType = refExpr->getType();
1290 // Otherwise, try to evaluate as an l-value.
1291 } else if (CEK != CEK_AsValueOnly &&
1292 refExpr->EvaluateAsLValue(result, getContext())) {
1293 resultIsReference = true;
1294 resultType = value->getType();
1298 return ConstantEmission();
1301 // In any case, if the initializer has side-effects, abandon ship.
1302 if (result.HasSideEffects)
1303 return ConstantEmission();
1305 // Emit as a constant.
1306 llvm::Constant *C = CGM.EmitConstantValue(result.Val, resultType, this);
1308 // Make sure we emit a debug reference to the global variable.
1309 // This should probably fire even for
1310 if (isa<VarDecl>(value)) {
1311 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1312 EmitDeclRefExprDbgValue(refExpr, result.Val);
1314 assert(isa<EnumConstantDecl>(value));
1315 EmitDeclRefExprDbgValue(refExpr, result.Val);
1318 // If we emitted a reference constant, we need to dereference that.
1319 if (resultIsReference)
1320 return ConstantEmission::forReference(C);
1322 return ConstantEmission::forValue(C);
1325 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1326 SourceLocation Loc) {
1327 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1328 lvalue.getType(), Loc, lvalue.getBaseInfo(),
1329 lvalue.getTBAAInfo(),
1330 lvalue.getTBAABaseType(), lvalue.getTBAAOffset(),
1331 lvalue.isNontemporal());
1334 static bool hasBooleanRepresentation(QualType Ty) {
1335 if (Ty->isBooleanType())
1338 if (const EnumType *ET = Ty->getAs<EnumType>())
1339 return ET->getDecl()->getIntegerType()->isBooleanType();
1341 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1342 return hasBooleanRepresentation(AT->getValueType());
1347 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1348 llvm::APInt &Min, llvm::APInt &End,
1349 bool StrictEnums, bool IsBool) {
1350 const EnumType *ET = Ty->getAs<EnumType>();
1351 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1352 ET && !ET->getDecl()->isFixed();
1353 if (!IsBool && !IsRegularCPlusPlusEnum)
1357 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1358 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1360 const EnumDecl *ED = ET->getDecl();
1361 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1362 unsigned Bitwidth = LTy->getScalarSizeInBits();
1363 unsigned NumNegativeBits = ED->getNumNegativeBits();
1364 unsigned NumPositiveBits = ED->getNumPositiveBits();
1366 if (NumNegativeBits) {
1367 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1368 assert(NumBits <= Bitwidth);
1369 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1372 assert(NumPositiveBits <= Bitwidth);
1373 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1374 Min = llvm::APInt(Bitwidth, 0);
1380 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1381 llvm::APInt Min, End;
1382 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1383 hasBooleanRepresentation(Ty)))
1386 llvm::MDBuilder MDHelper(getLLVMContext());
1387 return MDHelper.createRange(Min, End);
1390 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1391 SourceLocation Loc) {
1392 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1393 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1394 if (!HasBoolCheck && !HasEnumCheck)
1397 bool IsBool = hasBooleanRepresentation(Ty) ||
1398 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1399 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1400 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1401 if (!NeedsBoolCheck && !NeedsEnumCheck)
1404 // Single-bit booleans don't need to be checked. Special-case this to avoid
1405 // a bit width mismatch when handling bitfield values. This is handled by
1406 // EmitFromMemory for the non-bitfield case.
1408 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1411 llvm::APInt Min, End;
1412 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1415 SanitizerScope SanScope(this);
1419 Check = Builder.CreateICmpULE(
1420 Value, llvm::ConstantInt::get(getLLVMContext(), End));
1422 llvm::Value *Upper = Builder.CreateICmpSLE(
1423 Value, llvm::ConstantInt::get(getLLVMContext(), End));
1424 llvm::Value *Lower = Builder.CreateICmpSGE(
1425 Value, llvm::ConstantInt::get(getLLVMContext(), Min));
1426 Check = Builder.CreateAnd(Upper, Lower);
1428 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1429 EmitCheckTypeDescriptor(Ty)};
1430 SanitizerMask Kind =
1431 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1432 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1433 StaticArgs, EmitCheckValue(Value));
1437 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1440 LValueBaseInfo BaseInfo,
1441 llvm::MDNode *TBAAInfo,
1442 QualType TBAABaseType,
1443 uint64_t TBAAOffset,
1444 bool isNontemporal) {
1445 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1446 // For better performance, handle vector loads differently.
1447 if (Ty->isVectorType()) {
1448 const llvm::Type *EltTy = Addr.getElementType();
1450 const auto *VTy = cast<llvm::VectorType>(EltTy);
1452 // Handle vectors of size 3 like size 4 for better performance.
1453 if (VTy->getNumElements() == 3) {
1455 // Bitcast to vec4 type.
1456 llvm::VectorType *vec4Ty =
1457 llvm::VectorType::get(VTy->getElementType(), 4);
1458 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1460 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1462 // Shuffle vector to get vec3.
1463 V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1464 {0, 1, 2}, "extractVec");
1465 return EmitFromMemory(V, Ty);
1470 // Atomic operations have to be done on integral types.
1471 LValue AtomicLValue =
1472 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1473 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1474 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1477 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1478 if (isNontemporal) {
1479 llvm::MDNode *Node = llvm::MDNode::get(
1480 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1481 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1484 bool MayAlias = BaseInfo.getMayAlias();
1485 llvm::MDNode *TBAA = MayAlias
1486 ? CGM.getTBAAInfo(getContext().CharTy)
1487 : CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo, TBAAOffset);
1489 CGM.DecorateInstructionWithTBAA(Load, TBAA, MayAlias);
1492 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1493 // In order to prevent the optimizer from throwing away the check, don't
1494 // attach range metadata to the load.
1495 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1496 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1497 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1499 return EmitFromMemory(Load, Ty);
1502 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1503 // Bool has a different representation in memory than in registers.
1504 if (hasBooleanRepresentation(Ty)) {
1505 // This should really always be an i1, but sometimes it's already
1506 // an i8, and it's awkward to track those cases down.
1507 if (Value->getType()->isIntegerTy(1))
1508 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1509 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1510 "wrong value rep of bool");
1516 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1517 // Bool has a different representation in memory than in registers.
1518 if (hasBooleanRepresentation(Ty)) {
1519 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1520 "wrong value rep of bool");
1521 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1527 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1528 bool Volatile, QualType Ty,
1529 LValueBaseInfo BaseInfo,
1530 llvm::MDNode *TBAAInfo,
1531 bool isInit, QualType TBAABaseType,
1532 uint64_t TBAAOffset,
1533 bool isNontemporal) {
1535 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1536 // Handle vectors differently to get better performance.
1537 if (Ty->isVectorType()) {
1538 llvm::Type *SrcTy = Value->getType();
1539 auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1540 // Handle vec3 special.
1541 if (VecTy && VecTy->getNumElements() == 3) {
1542 // Our source is a vec3, do a shuffle vector to make it a vec4.
1543 llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1544 Builder.getInt32(2),
1545 llvm::UndefValue::get(Builder.getInt32Ty())};
1546 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1547 Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1548 MaskV, "extractVec");
1549 SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1551 if (Addr.getElementType() != SrcTy) {
1552 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1557 Value = EmitToMemory(Value, Ty);
1559 LValue AtomicLValue =
1560 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1561 if (Ty->isAtomicType() ||
1562 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1563 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1567 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1568 if (isNontemporal) {
1569 llvm::MDNode *Node =
1570 llvm::MDNode::get(Store->getContext(),
1571 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1572 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1575 bool MayAlias = BaseInfo.getMayAlias();
1576 llvm::MDNode *TBAA = MayAlias
1577 ? CGM.getTBAAInfo(getContext().CharTy)
1578 : CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo, TBAAOffset);
1580 CGM.DecorateInstructionWithTBAA(Store, TBAA, MayAlias);
1584 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1586 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1587 lvalue.getType(), lvalue.getBaseInfo(),
1588 lvalue.getTBAAInfo(), isInit, lvalue.getTBAABaseType(),
1589 lvalue.getTBAAOffset(), lvalue.isNontemporal());
1592 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1593 /// method emits the address of the lvalue, then loads the result as an rvalue,
1594 /// returning the rvalue.
1595 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1596 if (LV.isObjCWeak()) {
1597 // load of a __weak object.
1598 Address AddrWeakObj = LV.getAddress();
1599 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1602 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1603 // In MRC mode, we do a load+autorelease.
1604 if (!getLangOpts().ObjCAutoRefCount) {
1605 return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1608 // In ARC mode, we load retained and then consume the value.
1609 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
1610 Object = EmitObjCConsumeObject(LV.getType(), Object);
1611 return RValue::get(Object);
1614 if (LV.isSimple()) {
1615 assert(!LV.getType()->isFunctionType());
1617 // Everything needs a load.
1618 return RValue::get(EmitLoadOfScalar(LV, Loc));
1621 if (LV.isVectorElt()) {
1622 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1623 LV.isVolatileQualified());
1624 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1628 // If this is a reference to a subset of the elements of a vector, either
1629 // shuffle the input or extract/insert them as appropriate.
1630 if (LV.isExtVectorElt())
1631 return EmitLoadOfExtVectorElementLValue(LV);
1633 // Global Register variables always invoke intrinsics
1634 if (LV.isGlobalReg())
1635 return EmitLoadOfGlobalRegLValue(LV);
1637 assert(LV.isBitField() && "Unknown LValue type!");
1638 return EmitLoadOfBitfieldLValue(LV, Loc);
1641 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
1642 SourceLocation Loc) {
1643 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1645 // Get the output type.
1646 llvm::Type *ResLTy = ConvertType(LV.getType());
1648 Address Ptr = LV.getBitFieldAddress();
1649 llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1651 if (Info.IsSigned) {
1652 assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1653 unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1655 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1656 if (Info.Offset + HighBits)
1657 Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1660 Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1661 if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1662 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1666 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1667 EmitScalarRangeCheck(Val, LV.getType(), Loc);
1668 return RValue::get(Val);
1671 // If this is a reference to a subset of the elements of a vector, create an
1672 // appropriate shufflevector.
1673 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1674 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1675 LV.isVolatileQualified());
1677 const llvm::Constant *Elts = LV.getExtVectorElts();
1679 // If the result of the expression is a non-vector type, we must be extracting
1680 // a single element. Just codegen as an extractelement.
1681 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1683 unsigned InIdx = getAccessedFieldNo(0, Elts);
1684 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1685 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1688 // Always use shuffle vector to try to retain the original program structure
1689 unsigned NumResultElts = ExprVT->getNumElements();
1691 SmallVector<llvm::Constant*, 4> Mask;
1692 for (unsigned i = 0; i != NumResultElts; ++i)
1693 Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1695 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1696 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1698 return RValue::get(Vec);
1701 /// @brief Generates lvalue for partial ext_vector access.
1702 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
1703 Address VectorAddress = LV.getExtVectorAddress();
1704 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1705 QualType EQT = ExprVT->getElementType();
1706 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1708 Address CastToPointerElement =
1709 Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1710 "conv.ptr.element");
1712 const llvm::Constant *Elts = LV.getExtVectorElts();
1713 unsigned ix = getAccessedFieldNo(0, Elts);
1715 Address VectorBasePtrPlusIx =
1716 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1717 getContext().getTypeSizeInChars(EQT),
1720 return VectorBasePtrPlusIx;
1723 /// @brief Load of global gamed gegisters are always calls to intrinsics.
1724 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
1725 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1726 "Bad type for register variable");
1727 llvm::MDNode *RegName = cast<llvm::MDNode>(
1728 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1730 // We accept integer and pointer types only
1731 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1732 llvm::Type *Ty = OrigTy;
1733 if (OrigTy->isPointerTy())
1734 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1735 llvm::Type *Types[] = { Ty };
1737 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1738 llvm::Value *Call = Builder.CreateCall(
1739 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1740 if (OrigTy->isPointerTy())
1741 Call = Builder.CreateIntToPtr(Call, OrigTy);
1742 return RValue::get(Call);
1746 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1747 /// lvalue, where both are guaranteed to the have the same type, and that type
1749 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
1751 if (!Dst.isSimple()) {
1752 if (Dst.isVectorElt()) {
1753 // Read/modify/write the vector, inserting the new element.
1754 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
1755 Dst.isVolatileQualified());
1756 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1757 Dst.getVectorIdx(), "vecins");
1758 Builder.CreateStore(Vec, Dst.getVectorAddress(),
1759 Dst.isVolatileQualified());
1763 // If this is an update of extended vector elements, insert them as
1765 if (Dst.isExtVectorElt())
1766 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
1768 if (Dst.isGlobalReg())
1769 return EmitStoreThroughGlobalRegLValue(Src, Dst);
1771 assert(Dst.isBitField() && "Unknown LValue type");
1772 return EmitStoreThroughBitfieldLValue(Src, Dst);
1775 // There's special magic for assigning into an ARC-qualified l-value.
1776 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1778 case Qualifiers::OCL_None:
1779 llvm_unreachable("present but none");
1781 case Qualifiers::OCL_ExplicitNone:
1785 case Qualifiers::OCL_Strong:
1787 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1790 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1793 case Qualifiers::OCL_Weak:
1795 // Initialize and then skip the primitive store.
1796 EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
1798 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1801 case Qualifiers::OCL_Autoreleasing:
1802 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
1803 Src.getScalarVal()));
1804 // fall into the normal path
1809 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1810 // load of a __weak object.
1811 Address LvalueDst = Dst.getAddress();
1812 llvm::Value *src = Src.getScalarVal();
1813 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1817 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1818 // load of a __strong object.
1819 Address LvalueDst = Dst.getAddress();
1820 llvm::Value *src = Src.getScalarVal();
1821 if (Dst.isObjCIvar()) {
1822 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1823 llvm::Type *ResultType = IntPtrTy;
1824 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
1825 llvm::Value *RHS = dst.getPointer();
1826 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1828 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1829 "sub.ptr.lhs.cast");
1830 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
1831 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1833 } else if (Dst.isGlobalObjCRef()) {
1834 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1835 Dst.isThreadLocalRef());
1838 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1842 assert(Src.isScalar() && "Can't emit an agg store with this method");
1843 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
1846 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
1847 llvm::Value **Result) {
1848 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1849 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1850 Address Ptr = Dst.getBitFieldAddress();
1852 // Get the source value, truncated to the width of the bit-field.
1853 llvm::Value *SrcVal = Src.getScalarVal();
1855 // Cast the source to the storage type and shift it into place.
1856 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
1857 /*IsSigned=*/false);
1858 llvm::Value *MaskedVal = SrcVal;
1860 // See if there are other bits in the bitfield's storage we'll need to load
1861 // and mask together with source before storing.
1862 if (Info.StorageSize != Info.Size) {
1863 assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
1865 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
1867 // Mask the source value as needed.
1868 if (!hasBooleanRepresentation(Dst.getType()))
1869 SrcVal = Builder.CreateAnd(SrcVal,
1870 llvm::APInt::getLowBitsSet(Info.StorageSize,
1875 SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
1877 // Mask out the original value.
1878 Val = Builder.CreateAnd(Val,
1879 ~llvm::APInt::getBitsSet(Info.StorageSize,
1881 Info.Offset + Info.Size),
1884 // Or together the unchanged values and the source value.
1885 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
1887 assert(Info.Offset == 0);
1890 // Write the new value back out.
1891 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
1893 // Return the new value of the bit-field, if requested.
1895 llvm::Value *ResultVal = MaskedVal;
1897 // Sign extend the value if needed.
1898 if (Info.IsSigned) {
1899 assert(Info.Size <= Info.StorageSize);
1900 unsigned HighBits = Info.StorageSize - Info.Size;
1902 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
1903 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
1907 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
1909 *Result = EmitFromMemory(ResultVal, Dst.getType());
1913 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
1915 // This access turns into a read/modify/write of the vector. Load the input
1917 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
1918 Dst.isVolatileQualified());
1919 const llvm::Constant *Elts = Dst.getExtVectorElts();
1921 llvm::Value *SrcVal = Src.getScalarVal();
1923 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
1924 unsigned NumSrcElts = VTy->getNumElements();
1925 unsigned NumDstElts = Vec->getType()->getVectorNumElements();
1926 if (NumDstElts == NumSrcElts) {
1927 // Use shuffle vector is the src and destination are the same number of
1928 // elements and restore the vector mask since it is on the side it will be
1930 SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1931 for (unsigned i = 0; i != NumSrcElts; ++i)
1932 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
1934 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1935 Vec = Builder.CreateShuffleVector(SrcVal,
1936 llvm::UndefValue::get(Vec->getType()),
1938 } else if (NumDstElts > NumSrcElts) {
1939 // Extended the source vector to the same length and then shuffle it
1940 // into the destination.
1941 // FIXME: since we're shuffling with undef, can we just use the indices
1942 // into that? This could be simpler.
1943 SmallVector<llvm::Constant*, 4> ExtMask;
1944 for (unsigned i = 0; i != NumSrcElts; ++i)
1945 ExtMask.push_back(Builder.getInt32(i));
1946 ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
1947 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
1948 llvm::Value *ExtSrcVal =
1949 Builder.CreateShuffleVector(SrcVal,
1950 llvm::UndefValue::get(SrcVal->getType()),
1953 SmallVector<llvm::Constant*, 4> Mask;
1954 for (unsigned i = 0; i != NumDstElts; ++i)
1955 Mask.push_back(Builder.getInt32(i));
1957 // When the vector size is odd and .odd or .hi is used, the last element
1958 // of the Elts constant array will be one past the size of the vector.
1959 // Ignore the last element here, if it is greater than the mask size.
1960 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
1963 // modify when what gets shuffled in
1964 for (unsigned i = 0; i != NumSrcElts; ++i)
1965 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
1966 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1967 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
1969 // We should never shorten the vector
1970 llvm_unreachable("unexpected shorten vector length");
1973 // If the Src is a scalar (not a vector) it must be updating one element.
1974 unsigned InIdx = getAccessedFieldNo(0, Elts);
1975 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1976 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
1979 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
1980 Dst.isVolatileQualified());
1983 /// @brief Store of global named registers are always calls to intrinsics.
1984 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
1985 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
1986 "Bad type for register variable");
1987 llvm::MDNode *RegName = cast<llvm::MDNode>(
1988 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
1989 assert(RegName && "Register LValue is not metadata");
1991 // We accept integer and pointer types only
1992 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
1993 llvm::Type *Ty = OrigTy;
1994 if (OrigTy->isPointerTy())
1995 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1996 llvm::Type *Types[] = { Ty };
1998 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
1999 llvm::Value *Value = Src.getScalarVal();
2000 if (OrigTy->isPointerTy())
2001 Value = Builder.CreatePtrToInt(Value, Ty);
2003 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2006 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2007 // generating write-barries API. It is currently a global, ivar,
2009 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2011 bool IsMemberAccess=false) {
2012 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2015 if (isa<ObjCIvarRefExpr>(E)) {
2016 QualType ExpTy = E->getType();
2017 if (IsMemberAccess && ExpTy->isPointerType()) {
2018 // If ivar is a structure pointer, assigning to field of
2019 // this struct follows gcc's behavior and makes it a non-ivar
2020 // writer-barrier conservatively.
2021 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2022 if (ExpTy->isRecordType()) {
2023 LV.setObjCIvar(false);
2027 LV.setObjCIvar(true);
2028 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2029 LV.setBaseIvarExp(Exp->getBase());
2030 LV.setObjCArray(E->getType()->isArrayType());
2034 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2035 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2036 if (VD->hasGlobalStorage()) {
2037 LV.setGlobalObjCRef(true);
2038 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2041 LV.setObjCArray(E->getType()->isArrayType());
2045 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2046 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2050 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2051 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2052 if (LV.isObjCIvar()) {
2053 // If cast is to a structure pointer, follow gcc's behavior and make it
2054 // a non-ivar write-barrier.
2055 QualType ExpTy = E->getType();
2056 if (ExpTy->isPointerType())
2057 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
2058 if (ExpTy->isRecordType())
2059 LV.setObjCIvar(false);
2064 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2065 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2069 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2070 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2074 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2075 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2079 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2080 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2084 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2085 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2086 if (LV.isObjCIvar() && !LV.isObjCArray())
2087 // Using array syntax to assigning to what an ivar points to is not
2088 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2089 LV.setObjCIvar(false);
2090 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2091 // Using array syntax to assigning to what global points to is not
2092 // same as assigning to the global itself. {id *G;} G[i] = 0;
2093 LV.setGlobalObjCRef(false);
2097 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2098 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2099 // We don't know if member is an 'ivar', but this flag is looked at
2100 // only in the context of LV.isObjCIvar().
2101 LV.setObjCArray(E->getType()->isArrayType());
2106 static llvm::Value *
2107 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
2108 llvm::Value *V, llvm::Type *IRType,
2109 StringRef Name = StringRef()) {
2110 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2111 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2114 static LValue EmitThreadPrivateVarDeclLValue(
2115 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2116 llvm::Type *RealVarTy, SourceLocation Loc) {
2117 Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2118 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2119 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2120 return CGF.MakeAddrLValue(Addr, T, BaseInfo);
2123 Address CodeGenFunction::EmitLoadOfReference(Address Addr,
2124 const ReferenceType *RefTy,
2125 LValueBaseInfo *BaseInfo) {
2126 llvm::Value *Ptr = Builder.CreateLoad(Addr);
2127 return Address(Ptr, getNaturalTypeAlignment(RefTy->getPointeeType(),
2128 BaseInfo, /*forPointee*/ true));
2131 LValue CodeGenFunction::EmitLoadOfReferenceLValue(Address RefAddr,
2132 const ReferenceType *RefTy) {
2133 LValueBaseInfo BaseInfo;
2134 Address Addr = EmitLoadOfReference(RefAddr, RefTy, &BaseInfo);
2135 return MakeAddrLValue(Addr, RefTy->getPointeeType(), BaseInfo);
2138 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2139 const PointerType *PtrTy,
2140 LValueBaseInfo *BaseInfo) {
2141 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2142 return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2144 /*forPointeeType=*/true));
2147 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2148 const PointerType *PtrTy) {
2149 LValueBaseInfo BaseInfo;
2150 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo);
2151 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo);
2154 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2155 const Expr *E, const VarDecl *VD) {
2156 QualType T = E->getType();
2158 // If it's thread_local, emit a call to its wrapper function instead.
2159 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2160 CGF.CGM.getCXXABI().usesThreadWrapperFunction())
2161 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2163 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2164 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2165 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2166 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2167 Address Addr(V, Alignment);
2169 // Emit reference to the private copy of the variable if it is an OpenMP
2170 // threadprivate variable.
2171 if (CGF.getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>())
2172 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2174 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2175 LV = CGF.EmitLoadOfReferenceLValue(Addr, RefTy);
2177 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2178 LV = CGF.MakeAddrLValue(Addr, T, BaseInfo);
2180 setObjCGCLValueClass(CGF.getContext(), E, LV);
2184 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2185 const FunctionDecl *FD) {
2186 if (FD->hasAttr<WeakRefAttr>()) {
2187 ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2188 return aliasee.getPointer();
2191 llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2192 if (!FD->hasPrototype()) {
2193 if (const FunctionProtoType *Proto =
2194 FD->getType()->getAs<FunctionProtoType>()) {
2195 // Ugly case: for a K&R-style definition, the type of the definition
2196 // isn't the same as the type of a use. Correct for this with a
2198 QualType NoProtoType =
2199 CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2200 NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2201 V = llvm::ConstantExpr::getBitCast(V,
2202 CGM.getTypes().ConvertType(NoProtoType));
2208 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
2209 const Expr *E, const FunctionDecl *FD) {
2210 llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2211 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2212 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2213 return CGF.MakeAddrLValue(V, E->getType(), Alignment, BaseInfo);
2216 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2217 llvm::Value *ThisValue) {
2218 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2219 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2220 return CGF.EmitLValueForField(LV, FD);
2223 /// Named Registers are named metadata pointing to the register name
2224 /// which will be read from/written to as an argument to the intrinsic
2225 /// @llvm.read/write_register.
2226 /// So far, only the name is being passed down, but other options such as
2227 /// register type, allocation type or even optimization options could be
2228 /// passed down via the metadata node.
2229 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2230 SmallString<64> Name("llvm.named.register.");
2231 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2232 assert(Asm->getLabel().size() < 64-Name.size() &&
2233 "Register name too big");
2234 Name.append(Asm->getLabel());
2235 llvm::NamedMDNode *M =
2236 CGM.getModule().getOrInsertNamedMetadata(Name);
2237 if (M->getNumOperands() == 0) {
2238 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2240 llvm::Metadata *Ops[] = {Str};
2241 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2244 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2247 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2248 return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2251 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2252 const NamedDecl *ND = E->getDecl();
2253 QualType T = E->getType();
2255 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2256 // Global Named registers access via intrinsics only
2257 if (VD->getStorageClass() == SC_Register &&
2258 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2259 return EmitGlobalNamedRegister(VD, CGM);
2261 // A DeclRefExpr for a reference initialized by a constant expression can
2262 // appear without being odr-used. Directly emit the constant initializer.
2263 const Expr *Init = VD->getAnyInitializer(VD);
2264 if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2265 VD->isUsableInConstantExpressions(getContext()) &&
2266 VD->checkInitIsICE() &&
2267 // Do not emit if it is private OpenMP variable.
2268 !(E->refersToEnclosingVariableOrCapture() && CapturedStmtInfo &&
2269 LocalDeclMap.count(VD))) {
2270 llvm::Constant *Val =
2271 CGM.EmitConstantValue(*VD->evaluateValue(), VD->getType(), this);
2272 assert(Val && "failed to emit reference constant expression");
2273 // FIXME: Eventually we will want to emit vector element references.
2275 // Should we be using the alignment of the constant pointer we emitted?
2276 CharUnits Alignment = getNaturalTypeAlignment(E->getType(), nullptr,
2278 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2279 return MakeAddrLValue(Address(Val, Alignment), T, BaseInfo);
2282 // Check for captured variables.
2283 if (E->refersToEnclosingVariableOrCapture()) {
2284 if (auto *FD = LambdaCaptureFields.lookup(VD))
2285 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2286 else if (CapturedStmtInfo) {
2287 auto I = LocalDeclMap.find(VD);
2288 if (I != LocalDeclMap.end()) {
2289 if (auto RefTy = VD->getType()->getAs<ReferenceType>())
2290 return EmitLoadOfReferenceLValue(I->second, RefTy);
2291 return MakeAddrLValue(I->second, T);
2294 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2295 CapturedStmtInfo->getContextValue());
2296 bool MayAlias = CapLVal.getBaseInfo().getMayAlias();
2297 return MakeAddrLValue(
2298 Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2299 CapLVal.getType(), LValueBaseInfo(AlignmentSource::Decl, MayAlias));
2302 assert(isa<BlockDecl>(CurCodeDecl));
2303 Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
2304 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2305 return MakeAddrLValue(addr, T, BaseInfo);
2309 // FIXME: We should be able to assert this for FunctionDecls as well!
2310 // FIXME: We should be able to assert this for all DeclRefExprs, not just
2311 // those with a valid source location.
2312 assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2313 !E->getLocation().isValid()) &&
2314 "Should not use decl without marking it used!");
2316 if (ND->hasAttr<WeakRefAttr>()) {
2317 const auto *VD = cast<ValueDecl>(ND);
2318 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2319 return MakeAddrLValue(Aliasee, T,
2320 LValueBaseInfo(AlignmentSource::Decl, false));
2323 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2324 // Check if this is a global variable.
2325 if (VD->hasLinkage() || VD->isStaticDataMember())
2326 return EmitGlobalVarDeclLValue(*this, E, VD);
2328 Address addr = Address::invalid();
2330 // The variable should generally be present in the local decl map.
2331 auto iter = LocalDeclMap.find(VD);
2332 if (iter != LocalDeclMap.end()) {
2333 addr = iter->second;
2335 // Otherwise, it might be static local we haven't emitted yet for
2336 // some reason; most likely, because it's in an outer function.
2337 } else if (VD->isStaticLocal()) {
2338 addr = Address(CGM.getOrCreateStaticVarDecl(
2339 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2340 getContext().getDeclAlign(VD));
2342 // No other cases for now.
2344 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2348 // Check for OpenMP threadprivate variables.
2349 if (getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2350 return EmitThreadPrivateVarDeclLValue(
2351 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2355 // Drill into block byref variables.
2356 bool isBlockByref = VD->hasAttr<BlocksAttr>();
2358 addr = emitBlockByrefAddress(addr, VD);
2361 // Drill into reference types.
2363 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2364 LV = EmitLoadOfReferenceLValue(addr, RefTy);
2366 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2367 LV = MakeAddrLValue(addr, T, BaseInfo);
2370 bool isLocalStorage = VD->hasLocalStorage();
2372 bool NonGCable = isLocalStorage &&
2373 !VD->getType()->isReferenceType() &&
2376 LV.getQuals().removeObjCGCAttr();
2380 bool isImpreciseLifetime =
2381 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2382 if (isImpreciseLifetime)
2383 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2384 setObjCGCLValueClass(getContext(), E, LV);
2388 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2389 return EmitFunctionDeclLValue(*this, E, FD);
2391 // FIXME: While we're emitting a binding from an enclosing scope, all other
2392 // DeclRefExprs we see should be implicitly treated as if they also refer to
2393 // an enclosing scope.
2394 if (const auto *BD = dyn_cast<BindingDecl>(ND))
2395 return EmitLValue(BD->getBinding());
2397 llvm_unreachable("Unhandled DeclRefExpr");
2400 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2401 // __extension__ doesn't affect lvalue-ness.
2402 if (E->getOpcode() == UO_Extension)
2403 return EmitLValue(E->getSubExpr());
2405 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2406 switch (E->getOpcode()) {
2407 default: llvm_unreachable("Unknown unary operator lvalue!");
2409 QualType T = E->getSubExpr()->getType()->getPointeeType();
2410 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2412 LValueBaseInfo BaseInfo;
2413 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo);
2414 LValue LV = MakeAddrLValue(Addr, T, BaseInfo);
2415 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2417 // We should not generate __weak write barrier on indirect reference
2418 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2419 // But, we continue to generate __strong write barrier on indirect write
2420 // into a pointer to object.
2421 if (getLangOpts().ObjC1 &&
2422 getLangOpts().getGC() != LangOptions::NonGC &&
2424 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2429 LValue LV = EmitLValue(E->getSubExpr());
2430 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2432 // __real is valid on scalars. This is a faster way of testing that.
2433 // __imag can only produce an rvalue on scalars.
2434 if (E->getOpcode() == UO_Real &&
2435 !LV.getAddress().getElementType()->isStructTy()) {
2436 assert(E->getSubExpr()->getType()->isArithmeticType());
2440 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2443 (E->getOpcode() == UO_Real
2444 ? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
2445 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
2446 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo());
2447 ElemLV.getQuals().addQualifiers(LV.getQuals());
2452 LValue LV = EmitLValue(E->getSubExpr());
2453 bool isInc = E->getOpcode() == UO_PreInc;
2455 if (E->getType()->isAnyComplexType())
2456 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2458 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2464 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2465 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2467 LValueBaseInfo(AlignmentSource::Decl, false));
2470 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2471 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2473 LValueBaseInfo(AlignmentSource::Decl, false));
2476 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2477 auto SL = E->getFunctionName();
2478 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2479 StringRef FnName = CurFn->getName();
2480 if (FnName.startswith("\01"))
2481 FnName = FnName.substr(1);
2482 StringRef NameItems[] = {
2483 PredefinedExpr::getIdentTypeName(E->getIdentType()), FnName};
2484 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2485 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
2486 if (auto *BD = dyn_cast<BlockDecl>(CurCodeDecl)) {
2487 std::string Name = SL->getString();
2488 if (!Name.empty()) {
2489 unsigned Discriminator =
2490 CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2492 Name += "_" + Twine(Discriminator + 1).str();
2493 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2494 return MakeAddrLValue(C, E->getType(), BaseInfo);
2496 auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2497 return MakeAddrLValue(C, E->getType(), BaseInfo);
2500 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2501 return MakeAddrLValue(C, E->getType(), BaseInfo);
2504 /// Emit a type description suitable for use by a runtime sanitizer library. The
2505 /// format of a type descriptor is
2508 /// { i16 TypeKind, i16 TypeInfo }
2511 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2512 /// integer, 1 for a floating point value, and -1 for anything else.
2513 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2514 // Only emit each type's descriptor once.
2515 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2518 uint16_t TypeKind = -1;
2519 uint16_t TypeInfo = 0;
2521 if (T->isIntegerType()) {
2523 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2524 (T->isSignedIntegerType() ? 1 : 0);
2525 } else if (T->isFloatingType()) {
2527 TypeInfo = getContext().getTypeSize(T);
2530 // Format the type name as if for a diagnostic, including quotes and
2531 // optionally an 'aka'.
2532 SmallString<32> Buffer;
2533 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
2534 (intptr_t)T.getAsOpaquePtr(),
2535 StringRef(), StringRef(), None, Buffer,
2538 llvm::Constant *Components[] = {
2539 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2540 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2542 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2544 auto *GV = new llvm::GlobalVariable(
2545 CGM.getModule(), Descriptor->getType(),
2546 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2547 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2548 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
2550 // Remember the descriptor for this type.
2551 CGM.setTypeDescriptorInMap(T, GV);
2556 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
2557 llvm::Type *TargetTy = IntPtrTy;
2559 // Floating-point types which fit into intptr_t are bitcast to integers
2560 // and then passed directly (after zero-extension, if necessary).
2561 if (V->getType()->isFloatingPointTy()) {
2562 unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2563 if (Bits <= TargetTy->getIntegerBitWidth())
2564 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2568 // Integers which fit in intptr_t are zero-extended and passed directly.
2569 if (V->getType()->isIntegerTy() &&
2570 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2571 return Builder.CreateZExt(V, TargetTy);
2573 // Pointers are passed directly, everything else is passed by address.
2574 if (!V->getType()->isPointerTy()) {
2575 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2576 Builder.CreateStore(V, Ptr);
2577 V = Ptr.getPointer();
2579 return Builder.CreatePtrToInt(V, TargetTy);
2582 /// \brief Emit a representation of a SourceLocation for passing to a handler
2583 /// in a sanitizer runtime library. The format for this data is:
2585 /// struct SourceLocation {
2586 /// const char *Filename;
2587 /// int32_t Line, Column;
2590 /// For an invalid SourceLocation, the Filename pointer is null.
2591 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
2592 llvm::Constant *Filename;
2595 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
2596 if (PLoc.isValid()) {
2597 StringRef FilenameString = PLoc.getFilename();
2599 int PathComponentsToStrip =
2600 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2601 if (PathComponentsToStrip < 0) {
2602 assert(PathComponentsToStrip != INT_MIN);
2603 int PathComponentsToKeep = -PathComponentsToStrip;
2604 auto I = llvm::sys::path::rbegin(FilenameString);
2605 auto E = llvm::sys::path::rend(FilenameString);
2606 while (I != E && --PathComponentsToKeep)
2609 FilenameString = FilenameString.substr(I - E);
2610 } else if (PathComponentsToStrip > 0) {
2611 auto I = llvm::sys::path::begin(FilenameString);
2612 auto E = llvm::sys::path::end(FilenameString);
2613 while (I != E && PathComponentsToStrip--)
2618 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2620 FilenameString = llvm::sys::path::filename(FilenameString);
2623 auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2624 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
2625 cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2626 Filename = FilenameGV.getPointer();
2627 Line = PLoc.getLine();
2628 Column = PLoc.getColumn();
2630 Filename = llvm::Constant::getNullValue(Int8PtrTy);
2634 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2635 Builder.getInt32(Column)};
2637 return llvm::ConstantStruct::getAnon(Data);
2641 /// \brief Specify under what conditions this check can be recovered
2642 enum class CheckRecoverableKind {
2643 /// Always terminate program execution if this check fails.
2645 /// Check supports recovering, runtime has both fatal (noreturn) and
2646 /// non-fatal handlers for this check.
2648 /// Runtime conditionally aborts, always need to support recovery.
2653 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
2654 assert(llvm::countPopulation(Kind) == 1);
2656 case SanitizerKind::Vptr:
2657 return CheckRecoverableKind::AlwaysRecoverable;
2658 case SanitizerKind::Return:
2659 case SanitizerKind::Unreachable:
2660 return CheckRecoverableKind::Unrecoverable;
2662 return CheckRecoverableKind::Recoverable;
2667 struct SanitizerHandlerInfo {
2668 char const *const Name;
2673 const SanitizerHandlerInfo SanitizerHandlers[] = {
2674 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2675 LIST_SANITIZER_CHECKS
2676 #undef SANITIZER_CHECK
2679 static void emitCheckHandlerCall(CodeGenFunction &CGF,
2680 llvm::FunctionType *FnType,
2681 ArrayRef<llvm::Value *> FnArgs,
2682 SanitizerHandler CheckHandler,
2683 CheckRecoverableKind RecoverKind, bool IsFatal,
2684 llvm::BasicBlock *ContBB) {
2685 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2686 bool NeedsAbortSuffix =
2687 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2688 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2689 const StringRef CheckName = CheckInfo.Name;
2690 std::string FnName =
2691 ("__ubsan_handle_" + CheckName +
2692 (CheckInfo.Version ? "_v" + llvm::utostr(CheckInfo.Version) : "") +
2693 (NeedsAbortSuffix ? "_abort" : ""))
2696 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2698 llvm::AttrBuilder B;
2700 B.addAttribute(llvm::Attribute::NoReturn)
2701 .addAttribute(llvm::Attribute::NoUnwind);
2703 B.addAttribute(llvm::Attribute::UWTable);
2705 llvm::Value *Fn = CGF.CGM.CreateRuntimeFunction(
2707 llvm::AttributeList::get(CGF.getLLVMContext(),
2708 llvm::AttributeList::FunctionIndex, B),
2710 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2712 HandlerCall->setDoesNotReturn();
2713 CGF.Builder.CreateUnreachable();
2715 CGF.Builder.CreateBr(ContBB);
2719 void CodeGenFunction::EmitCheck(
2720 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2721 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
2722 ArrayRef<llvm::Value *> DynamicArgs) {
2723 assert(IsSanitizerScope);
2724 assert(Checked.size() > 0);
2725 assert(CheckHandler >= 0 &&
2726 CheckHandler < sizeof(SanitizerHandlers) / sizeof(*SanitizerHandlers));
2727 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
2729 llvm::Value *FatalCond = nullptr;
2730 llvm::Value *RecoverableCond = nullptr;
2731 llvm::Value *TrapCond = nullptr;
2732 for (int i = 0, n = Checked.size(); i < n; ++i) {
2733 llvm::Value *Check = Checked[i].first;
2734 // -fsanitize-trap= overrides -fsanitize-recover=.
2735 llvm::Value *&Cond =
2736 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2738 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2741 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2745 EmitTrapCheck(TrapCond);
2746 if (!FatalCond && !RecoverableCond)
2749 llvm::Value *JointCond;
2750 if (FatalCond && RecoverableCond)
2751 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2753 JointCond = FatalCond ? FatalCond : RecoverableCond;
2756 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2757 assert(SanOpts.has(Checked[0].second));
2759 for (int i = 1, n = Checked.size(); i < n; ++i) {
2760 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2761 "All recoverable kinds in a single check must be same!");
2762 assert(SanOpts.has(Checked[i].second));
2766 llvm::BasicBlock *Cont = createBasicBlock("cont");
2767 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2768 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2769 // Give hint that we very much don't expect to execute the handler
2770 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2771 llvm::MDBuilder MDHelper(getLLVMContext());
2772 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2773 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2774 EmitBlock(Handlers);
2776 // Handler functions take an i8* pointing to the (handler-specific) static
2777 // information block, followed by a sequence of intptr_t arguments
2778 // representing operand values.
2779 SmallVector<llvm::Value *, 4> Args;
2780 SmallVector<llvm::Type *, 4> ArgTypes;
2781 Args.reserve(DynamicArgs.size() + 1);
2782 ArgTypes.reserve(DynamicArgs.size() + 1);
2784 // Emit handler arguments and create handler function type.
2785 if (!StaticArgs.empty()) {
2786 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2788 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2789 llvm::GlobalVariable::PrivateLinkage, Info);
2790 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2791 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2792 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
2793 ArgTypes.push_back(Int8PtrTy);
2796 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
2797 Args.push_back(EmitCheckValue(DynamicArgs[i]));
2798 ArgTypes.push_back(IntPtrTy);
2801 llvm::FunctionType *FnType =
2802 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
2804 if (!FatalCond || !RecoverableCond) {
2805 // Simple case: we need to generate a single handler call, either
2806 // fatal, or non-fatal.
2807 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
2808 (FatalCond != nullptr), Cont);
2810 // Emit two handler calls: first one for set of unrecoverable checks,
2811 // another one for recoverable.
2812 llvm::BasicBlock *NonFatalHandlerBB =
2813 createBasicBlock("non_fatal." + CheckName);
2814 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
2815 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
2816 EmitBlock(FatalHandlerBB);
2817 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
2819 EmitBlock(NonFatalHandlerBB);
2820 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
2827 void CodeGenFunction::EmitCfiSlowPathCheck(
2828 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
2829 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
2830 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
2832 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
2833 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
2835 llvm::MDBuilder MDHelper(getLLVMContext());
2836 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2837 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
2841 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
2843 llvm::CallInst *CheckCall;
2845 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2847 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2848 llvm::GlobalVariable::PrivateLinkage, Info);
2849 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2850 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2852 llvm::Constant *SlowPathDiagFn = CGM.getModule().getOrInsertFunction(
2853 "__cfi_slowpath_diag",
2854 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
2856 CheckCall = Builder.CreateCall(
2858 {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
2860 llvm::Constant *SlowPathFn = CGM.getModule().getOrInsertFunction(
2862 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
2863 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
2866 CheckCall->setDoesNotThrow();
2871 // Emit a stub for __cfi_check function so that the linker knows about this
2872 // symbol in LTO mode.
2873 void CodeGenFunction::EmitCfiCheckStub() {
2874 llvm::Module *M = &CGM.getModule();
2875 auto &Ctx = M->getContext();
2876 llvm::Function *F = llvm::Function::Create(
2877 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
2878 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
2879 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
2880 // FIXME: consider emitting an intrinsic call like
2881 // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
2882 // which can be lowered in CrossDSOCFI pass to the actual contents of
2883 // __cfi_check. This would allow inlining of __cfi_check calls.
2884 llvm::CallInst::Create(
2885 llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
2886 llvm::ReturnInst::Create(Ctx, nullptr, BB);
2889 // This function is basically a switch over the CFI failure kind, which is
2890 // extracted from CFICheckFailData (1st function argument). Each case is either
2891 // llvm.trap or a call to one of the two runtime handlers, based on
2892 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
2893 // failure kind) traps, but this should really never happen. CFICheckFailData
2894 // can be nullptr if the calling module has -fsanitize-trap behavior for this
2895 // check kind; in this case __cfi_check_fail traps as well.
2896 void CodeGenFunction::EmitCfiCheckFail() {
2897 SanitizerScope SanScope(this);
2898 FunctionArgList Args;
2899 ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy,
2900 ImplicitParamDecl::Other);
2901 ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy,
2902 ImplicitParamDecl::Other);
2903 Args.push_back(&ArgData);
2904 Args.push_back(&ArgAddr);
2906 const CGFunctionInfo &FI =
2907 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
2909 llvm::Function *F = llvm::Function::Create(
2910 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
2911 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
2912 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
2914 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
2918 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
2919 CGM.getContext().VoidPtrTy, ArgData.getLocation());
2921 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
2922 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
2924 // Data == nullptr means the calling module has trap behaviour for this check.
2925 llvm::Value *DataIsNotNullPtr =
2926 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
2927 EmitTrapCheck(DataIsNotNullPtr);
2929 llvm::StructType *SourceLocationTy =
2930 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
2931 llvm::StructType *CfiCheckFailDataTy =
2932 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
2934 llvm::Value *V = Builder.CreateConstGEP2_32(
2936 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
2938 Address CheckKindAddr(V, getIntAlign());
2939 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
2941 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
2942 CGM.getLLVMContext(),
2943 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
2944 llvm::Value *ValidVtable = Builder.CreateZExt(
2945 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
2946 {Addr, AllVtables}),
2949 const std::pair<int, SanitizerMask> CheckKinds[] = {
2950 {CFITCK_VCall, SanitizerKind::CFIVCall},
2951 {CFITCK_NVCall, SanitizerKind::CFINVCall},
2952 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
2953 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
2954 {CFITCK_ICall, SanitizerKind::CFIICall}};
2956 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
2957 for (auto CheckKindMaskPair : CheckKinds) {
2958 int Kind = CheckKindMaskPair.first;
2959 SanitizerMask Mask = CheckKindMaskPair.second;
2961 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
2962 if (CGM.getLangOpts().Sanitize.has(Mask))
2963 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
2964 {Data, Addr, ValidVtable});
2966 EmitTrapCheck(Cond);
2970 // The only reference to this function will be created during LTO link.
2971 // Make sure it survives until then.
2972 CGM.addUsedGlobal(F);
2975 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
2976 llvm::BasicBlock *Cont = createBasicBlock("cont");
2978 // If we're optimizing, collapse all calls to trap down to just one per
2979 // function to save on code size.
2980 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
2981 TrapBB = createBasicBlock("trap");
2982 Builder.CreateCondBr(Checked, Cont, TrapBB);
2984 llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
2985 TrapCall->setDoesNotReturn();
2986 TrapCall->setDoesNotThrow();
2987 Builder.CreateUnreachable();
2989 Builder.CreateCondBr(Checked, Cont, TrapBB);
2995 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
2996 llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
2998 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
2999 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3000 CGM.getCodeGenOpts().TrapFuncName);
3001 TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3007 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
3008 LValueBaseInfo *BaseInfo) {
3009 assert(E->getType()->isArrayType() &&
3010 "Array to pointer decay must have array source type!");
3012 // Expressions of array type can't be bitfields or vector elements.
3013 LValue LV = EmitLValue(E);
3014 Address Addr = LV.getAddress();
3015 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3017 // If the array type was an incomplete type, we need to make sure
3018 // the decay ends up being the right type.
3019 llvm::Type *NewTy = ConvertType(E->getType());
3020 Addr = Builder.CreateElementBitCast(Addr, NewTy);
3022 // Note that VLA pointers are always decayed, so we don't need to do
3024 if (!E->getType()->isVariableArrayType()) {
3025 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3026 "Expected pointer to array");
3027 Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
3030 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
3031 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3034 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3035 /// array to pointer, return the array subexpression.
3036 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3037 // If this isn't just an array->pointer decay, bail out.
3038 const auto *CE = dyn_cast<CastExpr>(E);
3039 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3042 // If this is a decay from variable width array, bail out.
3043 const Expr *SubExpr = CE->getSubExpr();
3044 if (SubExpr->getType()->isVariableArrayType())
3050 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
3052 ArrayRef<llvm::Value*> indices,
3056 const llvm::Twine &name = "arrayidx") {
3058 return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3059 CodeGenFunction::NotSubtraction, loc,
3062 return CGF.Builder.CreateGEP(ptr, indices, name);
3066 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
3068 CharUnits eltSize) {
3069 // If we have a constant index, we can use the exact offset of the
3070 // element we're accessing.
3071 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3072 CharUnits offset = constantIdx->getZExtValue() * eltSize;
3073 return arrayAlign.alignmentAtOffset(offset);
3075 // Otherwise, use the worst-case alignment for any element.
3077 return arrayAlign.alignmentOfArrayElement(eltSize);
3081 static QualType getFixedSizeElementType(const ASTContext &ctx,
3082 const VariableArrayType *vla) {
3085 eltType = vla->getElementType();
3086 } while ((vla = ctx.getAsVariableArrayType(eltType)));
3090 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
3091 ArrayRef<llvm::Value *> indices,
3092 QualType eltType, bool inbounds,
3093 bool signedIndices, SourceLocation loc,
3094 const llvm::Twine &name = "arrayidx") {
3095 // All the indices except that last must be zero.
3097 for (auto idx : indices.drop_back())
3098 assert(isa<llvm::ConstantInt>(idx) &&
3099 cast<llvm::ConstantInt>(idx)->isZero());
3102 // Determine the element size of the statically-sized base. This is
3103 // the thing that the indices are expressed in terms of.
3104 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3105 eltType = getFixedSizeElementType(CGF.getContext(), vla);
3108 // We can use that to compute the best alignment of the element.
3109 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3110 CharUnits eltAlign =
3111 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3113 llvm::Value *eltPtr = emitArraySubscriptGEP(
3114 CGF, addr.getPointer(), indices, inbounds, signedIndices, loc, name);
3115 return Address(eltPtr, eltAlign);
3118 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3120 // The index must always be an integer, which is not an aggregate. Emit it
3121 // in lexical order (this complexity is, sadly, required by C++17).
3122 llvm::Value *IdxPre =
3123 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3124 bool SignedIndices = false;
3125 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3127 if (E->getLHS() != E->getIdx()) {
3128 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3129 Idx = EmitScalarExpr(E->getIdx());
3132 QualType IdxTy = E->getIdx()->getType();
3133 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3134 SignedIndices |= IdxSigned;
3136 if (SanOpts.has(SanitizerKind::ArrayBounds))
3137 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3139 // Extend or truncate the index type to 32 or 64-bits.
3140 if (Promote && Idx->getType() != IntPtrTy)
3141 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3147 // If the base is a vector type, then we are forming a vector element lvalue
3148 // with this subscript.
3149 if (E->getBase()->getType()->isVectorType() &&
3150 !isa<ExtVectorElementExpr>(E->getBase())) {
3151 // Emit the vector as an lvalue to get its address.
3152 LValue LHS = EmitLValue(E->getBase());
3153 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3154 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3155 return LValue::MakeVectorElt(LHS.getAddress(), Idx,
3156 E->getBase()->getType(),
3160 // All the other cases basically behave like simple offsetting.
3162 // Handle the extvector case we ignored above.
3163 if (isa<ExtVectorElementExpr>(E->getBase())) {
3164 LValue LV = EmitLValue(E->getBase());
3165 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3166 Address Addr = EmitExtVectorElementLValue(LV);
3168 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3169 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3170 SignedIndices, E->getExprLoc());
3171 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo());
3174 LValueBaseInfo BaseInfo;
3175 Address Addr = Address::invalid();
3176 if (const VariableArrayType *vla =
3177 getContext().getAsVariableArrayType(E->getType())) {
3178 // The base must be a pointer, which is not an aggregate. Emit
3179 // it. It needs to be emitted first in case it's what captures
3181 Addr = EmitPointerWithAlignment(E->getBase(), &BaseInfo);
3182 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3184 // The element count here is the total number of non-VLA elements.
3185 llvm::Value *numElements = getVLASize(vla).first;
3187 // Effectively, the multiply by the VLA size is part of the GEP.
3188 // GEP indexes are signed, and scaling an index isn't permitted to
3189 // signed-overflow, so we use the same semantics for our explicit
3190 // multiply. We suppress this if overflow is not undefined behavior.
3191 if (getLangOpts().isSignedOverflowDefined()) {
3192 Idx = Builder.CreateMul(Idx, numElements);
3194 Idx = Builder.CreateNSWMul(Idx, numElements);
3197 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3198 !getLangOpts().isSignedOverflowDefined(),
3199 SignedIndices, E->getExprLoc());
3201 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3202 // Indexing over an interface, as in "NSString *P; P[4];"
3204 // Emit the base pointer.
3205 Addr = EmitPointerWithAlignment(E->getBase(), &BaseInfo);
3206 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3208 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3209 llvm::Value *InterfaceSizeVal =
3210 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3212 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3214 // We don't necessarily build correct LLVM struct types for ObjC
3215 // interfaces, so we can't rely on GEP to do this scaling
3216 // correctly, so we need to cast to i8*. FIXME: is this actually
3217 // true? A lot of other things in the fragile ABI would break...
3218 llvm::Type *OrigBaseTy = Addr.getType();
3219 Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3222 CharUnits EltAlign =
3223 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3224 llvm::Value *EltPtr =
3225 emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3226 SignedIndices, E->getExprLoc());
3227 Addr = Address(EltPtr, EltAlign);
3230 Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3231 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3232 // If this is A[i] where A is an array, the frontend will have decayed the
3233 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3234 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3235 // "gep x, i" here. Emit one "gep A, 0, i".
3236 assert(Array->getType()->isArrayType() &&
3237 "Array to pointer decay must have array source type!");
3239 // For simple multidimensional array indexing, set the 'accessed' flag for
3240 // better bounds-checking of the base expression.
3241 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3242 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3244 ArrayLV = EmitLValue(Array);
3245 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3247 // Propagate the alignment from the array itself to the result.
3248 Addr = emitArraySubscriptGEP(
3249 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3250 E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3252 BaseInfo = ArrayLV.getBaseInfo();
3254 // The base must be a pointer; emit it with an estimate of its alignment.
3255 Addr = EmitPointerWithAlignment(E->getBase(), &BaseInfo);
3256 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3257 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3258 !getLangOpts().isSignedOverflowDefined(),
3259 SignedIndices, E->getExprLoc());
3262 LValue LV = MakeAddrLValue(Addr, E->getType(), BaseInfo);
3264 // TODO: Preserve/extend path TBAA metadata?
3266 if (getLangOpts().ObjC1 &&
3267 getLangOpts().getGC() != LangOptions::NonGC) {
3268 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3269 setObjCGCLValueClass(getContext(), E, LV);
3274 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
3275 LValueBaseInfo &BaseInfo,
3276 QualType BaseTy, QualType ElTy,
3277 bool IsLowerBound) {
3279 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3280 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3281 if (BaseTy->isArrayType()) {
3282 Address Addr = BaseLVal.getAddress();
3283 BaseInfo = BaseLVal.getBaseInfo();
3285 // If the array type was an incomplete type, we need to make sure
3286 // the decay ends up being the right type.
3287 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3288 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3290 // Note that VLA pointers are always decayed, so we don't need to do
3292 if (!BaseTy->isVariableArrayType()) {
3293 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3294 "Expected pointer to array");
3295 Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
3299 return CGF.Builder.CreateElementBitCast(Addr,
3300 CGF.ConvertTypeForMem(ElTy));
3302 LValueBaseInfo TypeInfo;
3303 CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeInfo);
3304 BaseInfo.mergeForCast(TypeInfo);
3305 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3307 return CGF.EmitPointerWithAlignment(Base, &BaseInfo);
3310 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3311 bool IsLowerBound) {
3314 dyn_cast<OMPArraySectionExpr>(E->getBase()->IgnoreParenImpCasts()))
3315 BaseTy = OMPArraySectionExpr::getBaseOriginalType(ASE);
3317 BaseTy = E->getBase()->getType();
3318 QualType ResultExprTy;
3319 if (auto *AT = getContext().getAsArrayType(BaseTy))
3320 ResultExprTy = AT->getElementType();
3322 ResultExprTy = BaseTy->getPointeeType();
3323 llvm::Value *Idx = nullptr;
3324 if (IsLowerBound || E->getColonLoc().isInvalid()) {
3325 // Requesting lower bound or upper bound, but without provided length and
3326 // without ':' symbol for the default length -> length = 1.
3327 // Idx = LowerBound ?: 0;
3328 if (auto *LowerBound = E->getLowerBound()) {
3329 Idx = Builder.CreateIntCast(
3330 EmitScalarExpr(LowerBound), IntPtrTy,
3331 LowerBound->getType()->hasSignedIntegerRepresentation());
3333 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3335 // Try to emit length or lower bound as constant. If this is possible, 1
3336 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3337 // IR (LB + Len) - 1.
3338 auto &C = CGM.getContext();
3339 auto *Length = E->getLength();
3340 llvm::APSInt ConstLength;
3342 // Idx = LowerBound + Length - 1;
3343 if (Length->isIntegerConstantExpr(ConstLength, C)) {
3344 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3347 auto *LowerBound = E->getLowerBound();
3348 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3349 if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3350 ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3351 LowerBound = nullptr;
3355 else if (!LowerBound)
3358 if (Length || LowerBound) {
3359 auto *LowerBoundVal =
3361 ? Builder.CreateIntCast(
3362 EmitScalarExpr(LowerBound), IntPtrTy,
3363 LowerBound->getType()->hasSignedIntegerRepresentation())
3364 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3367 ? Builder.CreateIntCast(
3368 EmitScalarExpr(Length), IntPtrTy,
3369 Length->getType()->hasSignedIntegerRepresentation())
3370 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3371 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3373 !getLangOpts().isSignedOverflowDefined());
3374 if (Length && LowerBound) {
3375 Idx = Builder.CreateSub(
3376 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3377 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3380 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3382 // Idx = ArraySize - 1;
3383 QualType ArrayTy = BaseTy->isPointerType()
3384 ? E->getBase()->IgnoreParenImpCasts()->getType()
3386 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3387 Length = VAT->getSizeExpr();
3388 if (Length->isIntegerConstantExpr(ConstLength, C))
3391 auto *CAT = C.getAsConstantArrayType(ArrayTy);
3392 ConstLength = CAT->getSize();
3395 auto *LengthVal = Builder.CreateIntCast(
3396 EmitScalarExpr(Length), IntPtrTy,
3397 Length->getType()->hasSignedIntegerRepresentation());
3398 Idx = Builder.CreateSub(
3399 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3400 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3402 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3404 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3410 Address EltPtr = Address::invalid();
3411 LValueBaseInfo BaseInfo;
3412 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3413 // The base must be a pointer, which is not an aggregate. Emit
3414 // it. It needs to be emitted first in case it's what captures
3417 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, BaseTy,
3418 VLA->getElementType(), IsLowerBound);
3419 // The element count here is the total number of non-VLA elements.
3420 llvm::Value *NumElements = getVLASize(VLA).first;
3422 // Effectively, the multiply by the VLA size is part of the GEP.
3423 // GEP indexes are signed, and scaling an index isn't permitted to
3424 // signed-overflow, so we use the same semantics for our explicit
3425 // multiply. We suppress this if overflow is not undefined behavior.
3426 if (getLangOpts().isSignedOverflowDefined())
3427 Idx = Builder.CreateMul(Idx, NumElements);
3429 Idx = Builder.CreateNSWMul(Idx, NumElements);
3430 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3431 !getLangOpts().isSignedOverflowDefined(),
3432 /*SignedIndices=*/false, E->getExprLoc());
3433 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3434 // If this is A[i] where A is an array, the frontend will have decayed the
3435 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3436 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3437 // "gep x, i" here. Emit one "gep A, 0, i".
3438 assert(Array->getType()->isArrayType() &&
3439 "Array to pointer decay must have array source type!");
3441 // For simple multidimensional array indexing, set the 'accessed' flag for
3442 // better bounds-checking of the base expression.
3443 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3444 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3446 ArrayLV = EmitLValue(Array);
3448 // Propagate the alignment from the array itself to the result.
3449 EltPtr = emitArraySubscriptGEP(
3450 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3451 ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3452 /*SignedIndices=*/false, E->getExprLoc());
3453 BaseInfo = ArrayLV.getBaseInfo();
3455 Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3456 BaseTy, ResultExprTy, IsLowerBound);
3457 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3458 !getLangOpts().isSignedOverflowDefined(),
3459 /*SignedIndices=*/false, E->getExprLoc());
3462 return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo);
3465 LValue CodeGenFunction::
3466 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
3467 // Emit the base vector as an l-value.
3470 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3472 // If it is a pointer to a vector, emit the address and form an lvalue with
3474 LValueBaseInfo BaseInfo;
3475 Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo);
3476 const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3477 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo);
3478 Base.getQuals().removeObjCGCAttr();
3479 } else if (E->getBase()->isGLValue()) {
3480 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3481 // emit the base as an lvalue.
3482 assert(E->getBase()->getType()->isVectorType());
3483 Base = EmitLValue(E->getBase());
3485 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3486 assert(E->getBase()->getType()->isVectorType() &&
3487 "Result must be a vector");
3488 llvm::Value *Vec = EmitScalarExpr(E->getBase());
3490 // Store the vector to memory (because LValue wants an address).
3491 Address VecMem = CreateMemTemp(E->getBase()->getType());
3492 Builder.CreateStore(Vec, VecMem);
3493 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3494 LValueBaseInfo(AlignmentSource::Decl, false));
3498 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
3500 // Encode the element access list into a vector of unsigned indices.
3501 SmallVector<uint32_t, 4> Indices;
3502 E->getEncodedElementAccess(Indices);
3504 if (Base.isSimple()) {
3505 llvm::Constant *CV =
3506 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3507 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3508 Base.getBaseInfo());
3510 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3512 llvm::Constant *BaseElts = Base.getExtVectorElts();
3513 SmallVector<llvm::Constant *, 4> CElts;
3515 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3516 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3517 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3518 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
3519 Base.getBaseInfo());
3522 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
3523 Expr *BaseExpr = E->getBase();
3524 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3527 LValueBaseInfo BaseInfo;
3528 Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo);
3529 QualType PtrTy = BaseExpr->getType()->getPointeeType();
3530 SanitizerSet SkippedChecks;
3531 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3533 SkippedChecks.set(SanitizerKind::Alignment, true);
3534 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3535 SkippedChecks.set(SanitizerKind::Null, true);
3536 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3537 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3538 BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo);
3540 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3542 NamedDecl *ND = E->getMemberDecl();
3543 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3544 LValue LV = EmitLValueForField(BaseLV, Field);
3545 setObjCGCLValueClass(getContext(), E, LV);
3549 if (auto *VD = dyn_cast<VarDecl>(ND))
3550 return EmitGlobalVarDeclLValue(*this, E, VD);
3552 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3553 return EmitFunctionDeclLValue(*this, E, FD);
3555 llvm_unreachable("Unhandled member declaration!");
3558 /// Given that we are currently emitting a lambda, emit an l-value for
3559 /// one of its members.
3560 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
3561 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3562 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3563 QualType LambdaTagType =
3564 getContext().getTagDeclType(Field->getParent());
3565 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3566 return EmitLValueForField(LambdaLV, Field);
3569 /// Drill down to the storage of a field without walking into
3570 /// reference types.
3572 /// The resulting address doesn't necessarily have the right type.
3573 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
3574 const FieldDecl *field) {
3575 const RecordDecl *rec = field->getParent();
3578 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3581 // Adjust the alignment down to the given offset.
3582 // As a special case, if the LLVM field index is 0, we know that this
3584 assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
3585 .getFieldOffset(field->getFieldIndex()) == 0) &&
3586 "LLVM field at index zero had non-zero offset?");
3588 auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
3589 auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
3590 offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
3593 return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
3596 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
3597 const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
3601 if (RD->isDynamicClass())
3604 for (const auto &Base : RD->bases())
3605 if (hasAnyVptr(Base.getType(), Context))
3608 for (const FieldDecl *Field : RD->fields())
3609 if (hasAnyVptr(Field->getType(), Context))
3615 LValue CodeGenFunction::EmitLValueForField(LValue base,
3616 const FieldDecl *field) {
3617 LValueBaseInfo BaseInfo = base.getBaseInfo();
3618 AlignmentSource fieldAlignSource =
3619 getFieldAlignmentSource(BaseInfo.getAlignmentSource());
3620 LValueBaseInfo FieldBaseInfo(fieldAlignSource, BaseInfo.getMayAlias());
3622 const RecordDecl *rec = field->getParent();
3623 if (rec->isUnion() || rec->hasAttr<MayAliasAttr>())
3624 FieldBaseInfo.setMayAlias(true);
3625 bool mayAlias = FieldBaseInfo.getMayAlias();
3627 if (field->isBitField()) {
3628 const CGRecordLayout &RL =
3629 CGM.getTypes().getCGRecordLayout(field->getParent());
3630 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3631 Address Addr = base.getAddress();
3632 unsigned Idx = RL.getLLVMFieldNo(field);
3634 // For structs, we GEP to the field that the record layout suggests.
3635 Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
3637 // Get the access type.
3638 llvm::Type *FieldIntTy =
3639 llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3640 if (Addr.getElementType() != FieldIntTy)
3641 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3643 QualType fieldType =
3644 field->getType().withCVRQualifiers(base.getVRQualifiers());
3645 return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo);
3648 QualType type = field->getType();
3649 Address addr = base.getAddress();
3650 unsigned cvr = base.getVRQualifiers();
3651 bool TBAAPath = CGM.getCodeGenOpts().StructPathTBAA;
3652 if (rec->isUnion()) {
3653 // For unions, there is no pointer adjustment.
3654 assert(!type->isReferenceType() && "union has reference member");
3655 // TODO: handle path-aware TBAA for union.
3658 const auto FieldType = field->getType();
3659 if (CGM.getCodeGenOpts().StrictVTablePointers &&
3660 hasAnyVptr(FieldType, getContext()))
3661 // Because unions can easily skip invariant.barriers, we need to add
3662 // a barrier every time CXXRecord field with vptr is referenced.
3663 addr = Address(Builder.CreateInvariantGroupBarrier(addr.getPointer()),
3664 addr.getAlignment());
3666 // For structs, we GEP to the field that the record layout suggests.
3667 addr = emitAddrOfFieldStorage(*this, addr, field);
3669 // If this is a reference field, load the reference right now.
3670 if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
3671 llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
3672 if (cvr & Qualifiers::Volatile) load->setVolatile(true);
3674 // Loading the reference will disable path-aware TBAA.
3676 if (CGM.shouldUseTBAA()) {
3679 tbaa = CGM.getTBAAInfo(getContext().CharTy);
3681 tbaa = CGM.getTBAAInfo(type);
3683 CGM.DecorateInstructionWithTBAA(load, tbaa);
3687 type = refType->getPointeeType();
3689 CharUnits alignment =
3690 getNaturalTypeAlignment(type, &FieldBaseInfo, /*pointee*/ true);
3691 FieldBaseInfo.setMayAlias(false);
3692 addr = Address(load, alignment);
3694 // Qualifiers on the struct don't apply to the referencee, and
3695 // we'll pick up CVR from the actual type later, so reset these
3696 // additional qualifiers now.
3701 // Make sure that the address is pointing to the right type. This is critical
3702 // for both unions and structs. A union needs a bitcast, a struct element
3703 // will need a bitcast if the LLVM type laid out doesn't match the desired
3705 addr = Builder.CreateElementBitCast(addr,
3706 CGM.getTypes().ConvertTypeForMem(type),
3709 if (field->hasAttr<AnnotateAttr>())
3710 addr = EmitFieldAnnotations(field, addr);
3712 LValue LV = MakeAddrLValue(addr, type, FieldBaseInfo);
3713 LV.getQuals().addCVRQualifiers(cvr);
3715 const ASTRecordLayout &Layout =
3716 getContext().getASTRecordLayout(field->getParent());
3717 // Set the base type to be the base type of the base LValue and
3718 // update offset to be relative to the base type.
3719 LV.setTBAABaseType(mayAlias ? getContext().CharTy : base.getTBAABaseType());
3720 LV.setTBAAOffset(mayAlias ? 0 : base.getTBAAOffset() +
3721 Layout.getFieldOffset(field->getFieldIndex()) /
3722 getContext().getCharWidth());
3725 // __weak attribute on a field is ignored.
3726 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3727 LV.getQuals().removeObjCGCAttr();
3729 // Fields of may_alias structs act like 'char' for TBAA purposes.
3730 // FIXME: this should get propagated down through anonymous structs
3732 if (mayAlias && LV.getTBAAInfo())
3733 LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
3739 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
3740 const FieldDecl *Field) {
3741 QualType FieldType = Field->getType();
3743 if (!FieldType->isReferenceType())
3744 return EmitLValueForField(Base, Field);
3746 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3748 // Make sure that the address is pointing to the right type.
3749 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3750 V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3752 // TODO: access-path TBAA?
3753 LValueBaseInfo BaseInfo = Base.getBaseInfo();
3754 LValueBaseInfo FieldBaseInfo(
3755 getFieldAlignmentSource(BaseInfo.getAlignmentSource()),
3756 BaseInfo.getMayAlias());
3757 return MakeAddrLValue(V, FieldType, FieldBaseInfo);
3760 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
3761 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
3762 if (E->isFileScope()) {
3763 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
3764 return MakeAddrLValue(GlobalPtr, E->getType(), BaseInfo);
3766 if (E->getType()->isVariablyModifiedType())
3767 // make sure to emit the VLA size.
3768 EmitVariablyModifiedType(E->getType());
3770 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
3771 const Expr *InitExpr = E->getInitializer();
3772 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), BaseInfo);
3774 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
3780 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
3781 if (!E->isGLValue())
3782 // Initializing an aggregate temporary in C++11: T{...}.
3783 return EmitAggExprToLValue(E);
3785 // An lvalue initializer list must be initializing a reference.
3786 assert(E->isTransparent() && "non-transparent glvalue init list");
3787 return EmitLValue(E->getInit(0));
3790 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
3791 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
3792 /// LValue is returned and the current block has been terminated.
3793 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
3794 const Expr *Operand) {
3795 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
3796 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
3800 return CGF.EmitLValue(Operand);
3803 LValue CodeGenFunction::
3804 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
3805 if (!expr->isGLValue()) {
3806 // ?: here should be an aggregate.
3807 assert(hasAggregateEvaluationKind(expr->getType()) &&
3808 "Unexpected conditional operator!");
3809 return EmitAggExprToLValue(expr);
3812 OpaqueValueMapping binding(*this, expr);
3814 const Expr *condExpr = expr->getCond();
3816 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
3817 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
3818 if (!CondExprBool) std::swap(live, dead);
3820 if (!ContainsLabel(dead)) {
3821 // If the true case is live, we need to track its region.
3823 incrementProfileCounter(expr);
3824 return EmitLValue(live);
3828 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
3829 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
3830 llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
3832 ConditionalEvaluation eval(*this);
3833 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
3835 // Any temporaries created here are conditional.
3836 EmitBlock(lhsBlock);
3837 incrementProfileCounter(expr);
3839 Optional<LValue> lhs =
3840 EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
3843 if (lhs && !lhs->isSimple())
3844 return EmitUnsupportedLValue(expr, "conditional operator");
3846 lhsBlock = Builder.GetInsertBlock();
3848 Builder.CreateBr(contBlock);
3850 // Any temporaries created here are conditional.
3851 EmitBlock(rhsBlock);
3853 Optional<LValue> rhs =
3854 EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
3856 if (rhs && !rhs->isSimple())
3857 return EmitUnsupportedLValue(expr, "conditional operator");
3858 rhsBlock = Builder.GetInsertBlock();
3860 EmitBlock(contBlock);
3863 llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
3865 phi->addIncoming(lhs->getPointer(), lhsBlock);
3866 phi->addIncoming(rhs->getPointer(), rhsBlock);
3867 Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
3868 AlignmentSource alignSource =
3869 std::max(lhs->getBaseInfo().getAlignmentSource(),
3870 rhs->getBaseInfo().getAlignmentSource());
3871 bool MayAlias = lhs->getBaseInfo().getMayAlias() ||
3872 rhs->getBaseInfo().getMayAlias();
3873 return MakeAddrLValue(result, expr->getType(),
3874 LValueBaseInfo(alignSource, MayAlias));
3876 assert((lhs || rhs) &&
3877 "both operands of glvalue conditional are throw-expressions?");
3878 return lhs ? *lhs : *rhs;
3882 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
3883 /// type. If the cast is to a reference, we can have the usual lvalue result,
3884 /// otherwise if a cast is needed by the code generator in an lvalue context,
3885 /// then it must mean that we need the address of an aggregate in order to
3886 /// access one of its members. This can happen for all the reasons that casts
3887 /// are permitted with aggregate result, including noop aggregate casts, and
3888 /// cast from scalar to union.
3889 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
3890 switch (E->getCastKind()) {
3893 case CK_ArrayToPointerDecay:
3894 case CK_FunctionToPointerDecay:
3895 case CK_NullToMemberPointer:
3896 case CK_NullToPointer:
3897 case CK_IntegralToPointer:
3898 case CK_PointerToIntegral:
3899 case CK_PointerToBoolean:
3900 case CK_VectorSplat:
3901 case CK_IntegralCast:
3902 case CK_BooleanToSignedIntegral:
3903 case CK_IntegralToBoolean:
3904 case CK_IntegralToFloating:
3905 case CK_FloatingToIntegral:
3906 case CK_FloatingToBoolean:
3907 case CK_FloatingCast:
3908 case CK_FloatingRealToComplex:
3909 case CK_FloatingComplexToReal:
3910 case CK_FloatingComplexToBoolean:
3911 case CK_FloatingComplexCast:
3912 case CK_FloatingComplexToIntegralComplex:
3913 case CK_IntegralRealToComplex:
3914 case CK_IntegralComplexToReal:
3915 case CK_IntegralComplexToBoolean:
3916 case CK_IntegralComplexCast:
3917 case CK_IntegralComplexToFloatingComplex:
3918 case CK_DerivedToBaseMemberPointer:
3919 case CK_BaseToDerivedMemberPointer:
3920 case CK_MemberPointerToBoolean:
3921 case CK_ReinterpretMemberPointer:
3922 case CK_AnyPointerToBlockPointerCast:
3923 case CK_ARCProduceObject:
3924 case CK_ARCConsumeObject:
3925 case CK_ARCReclaimReturnedObject:
3926 case CK_ARCExtendBlockObject:
3927 case CK_CopyAndAutoreleaseBlockObject:
3928 case CK_AddressSpaceConversion:
3929 case CK_IntToOCLSampler:
3930 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
3933 llvm_unreachable("dependent cast kind in IR gen!");
3935 case CK_BuiltinFnToFnPtr:
3936 llvm_unreachable("builtin functions are handled elsewhere");
3938 // These are never l-values; just use the aggregate emission code.
3939 case CK_NonAtomicToAtomic:
3940 case CK_AtomicToNonAtomic:
3941 return EmitAggExprToLValue(E);
3944 LValue LV = EmitLValue(E->getSubExpr());
3945 Address V = LV.getAddress();
3946 const auto *DCE = cast<CXXDynamicCastExpr>(E);
3947 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
3950 case CK_ConstructorConversion:
3951 case CK_UserDefinedConversion:
3952 case CK_CPointerToObjCPointerCast:
3953 case CK_BlockPointerToObjCPointerCast:
3955 case CK_LValueToRValue:
3956 return EmitLValue(E->getSubExpr());
3958 case CK_UncheckedDerivedToBase:
3959 case CK_DerivedToBase: {
3960 const RecordType *DerivedClassTy =
3961 E->getSubExpr()->getType()->getAs<RecordType>();
3962 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3964 LValue LV = EmitLValue(E->getSubExpr());
3965 Address This = LV.getAddress();
3967 // Perform the derived-to-base conversion
3968 Address Base = GetAddressOfBaseClass(
3969 This, DerivedClassDecl, E->path_begin(), E->path_end(),
3970 /*NullCheckValue=*/false, E->getExprLoc());
3972 return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo());
3975 return EmitAggExprToLValue(E);
3976 case CK_BaseToDerived: {
3977 const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
3978 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3980 LValue LV = EmitLValue(E->getSubExpr());
3982 // Perform the base-to-derived conversion
3984 GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
3985 E->path_begin(), E->path_end(),
3986 /*NullCheckValue=*/false);
3988 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
3989 // performed and the object is not of the derived type.
3990 if (sanitizePerformTypeCheck())
3991 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
3992 Derived.getPointer(), E->getType());
3994 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
3995 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
3996 /*MayBeNull=*/false,
3997 CFITCK_DerivedCast, E->getLocStart());
3999 return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo());
4001 case CK_LValueBitCast: {
4002 // This must be a reinterpret_cast (or c-style equivalent).
4003 const auto *CE = cast<ExplicitCastExpr>(E);
4005 CGM.EmitExplicitCastExprType(CE, this);
4006 LValue LV = EmitLValue(E->getSubExpr());
4007 Address V = Builder.CreateBitCast(LV.getAddress(),
4008 ConvertType(CE->getTypeAsWritten()));
4010 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4011 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4012 /*MayBeNull=*/false,
4013 CFITCK_UnrelatedCast, E->getLocStart());
4015 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo());
4017 case CK_ObjCObjectLValueCast: {
4018 LValue LV = EmitLValue(E->getSubExpr());
4019 Address V = Builder.CreateElementBitCast(LV.getAddress(),
4020 ConvertType(E->getType()));
4021 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo());
4023 case CK_ZeroToOCLQueue:
4024 llvm_unreachable("NULL to OpenCL queue lvalue cast is not valid");
4025 case CK_ZeroToOCLEvent:
4026 llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
4029 llvm_unreachable("Unhandled lvalue cast kind?");
4032 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
4033 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
4034 return getOpaqueLValueMapping(e);
4037 RValue CodeGenFunction::EmitRValueForField(LValue LV,
4038 const FieldDecl *FD,
4039 SourceLocation Loc) {
4040 QualType FT = FD->getType();
4041 LValue FieldLV = EmitLValueForField(LV, FD);
4042 switch (getEvaluationKind(FT)) {
4044 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4046 return FieldLV.asAggregateRValue();
4048 // This routine is used to load fields one-by-one to perform a copy, so
4049 // don't load reference fields.
4050 if (FD->getType()->isReferenceType())
4051 return RValue::get(FieldLV.getPointer());
4052 return EmitLoadOfLValue(FieldLV, Loc);
4054 llvm_unreachable("bad evaluation kind");
4057 //===--------------------------------------------------------------------===//
4058 // Expression Emission
4059 //===--------------------------------------------------------------------===//
4061 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
4062 ReturnValueSlot ReturnValue) {
4063 // Builtins never have block type.
4064 if (E->getCallee()->getType()->isBlockPointerType())
4065 return EmitBlockCallExpr(E, ReturnValue);
4067 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4068 return EmitCXXMemberCallExpr(CE, ReturnValue);
4070 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4071 return EmitCUDAKernelCallExpr(CE, ReturnValue);
4073 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4074 if (const CXXMethodDecl *MD =
4075 dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4076 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4078 CGCallee callee = EmitCallee(E->getCallee());
4080 if (callee.isBuiltin()) {
4081 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4085 if (callee.isPseudoDestructor()) {
4086 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
4089 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4092 /// Emit a CallExpr without considering whether it might be a subclass.
4093 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
4094 ReturnValueSlot ReturnValue) {
4095 CGCallee Callee = EmitCallee(E->getCallee());
4096 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4099 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
4100 if (auto builtinID = FD->getBuiltinID()) {
4101 return CGCallee::forBuiltin(builtinID, FD);
4104 llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4105 return CGCallee::forDirect(calleePtr, FD);
4108 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
4109 E = E->IgnoreParens();
4111 // Look through function-to-pointer decay.
4112 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4113 if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4114 ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4115 return EmitCallee(ICE->getSubExpr());
4118 // Resolve direct calls.
4119 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4120 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4121 return EmitDirectCallee(*this, FD);
4123 } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4124 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4125 EmitIgnoredExpr(ME->getBase());
4126 return EmitDirectCallee(*this, FD);
4129 // Look through template substitutions.
4130 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4131 return EmitCallee(NTTP->getReplacement());
4133 // Treat pseudo-destructor calls differently.
4134 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4135 return CGCallee::forPseudoDestructor(PDE);
4138 // Otherwise, we have an indirect reference.
4139 llvm::Value *calleePtr;
4140 QualType functionType;
4141 if (auto ptrType = E->getType()->getAs<PointerType>()) {
4142 calleePtr = EmitScalarExpr(E);
4143 functionType = ptrType->getPointeeType();
4145 functionType = E->getType();
4146 calleePtr = EmitLValue(E).getPointer();
4148 assert(functionType->isFunctionType());
4149 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(),
4150 E->getReferencedDeclOfCallee());
4151 CGCallee callee(calleeInfo, calleePtr);
4155 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
4156 // Comma expressions just emit their LHS then their RHS as an l-value.
4157 if (E->getOpcode() == BO_Comma) {
4158 EmitIgnoredExpr(E->getLHS());
4159 EnsureInsertPoint();
4160 return EmitLValue(E->getRHS());
4163 if (E->getOpcode() == BO_PtrMemD ||
4164 E->getOpcode() == BO_PtrMemI)
4165 return EmitPointerToDataMemberBinaryExpr(E);
4167 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4169 // Note that in all of these cases, __block variables need the RHS
4170 // evaluated first just in case the variable gets moved by the RHS.
4172 switch (getEvaluationKind(E->getType())) {
4174 switch (E->getLHS()->getType().getObjCLifetime()) {
4175 case Qualifiers::OCL_Strong:
4176 return EmitARCStoreStrong(E, /*ignored*/ false).first;
4178 case Qualifiers::OCL_Autoreleasing:
4179 return EmitARCStoreAutoreleasing(E).first;
4181 // No reason to do any of these differently.
4182 case Qualifiers::OCL_None:
4183 case Qualifiers::OCL_ExplicitNone:
4184 case Qualifiers::OCL_Weak:
4188 RValue RV = EmitAnyExpr(E->getRHS());
4189 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
4191 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
4192 EmitStoreThroughLValue(RV, LV);
4197 return EmitComplexAssignmentLValue(E);
4200 return EmitAggExprToLValue(E);
4202 llvm_unreachable("bad evaluation kind");
4205 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
4206 RValue RV = EmitCallExpr(E);
4209 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4210 LValueBaseInfo(AlignmentSource::Decl, false));
4212 assert(E->getCallReturnType(getContext())->isReferenceType() &&
4213 "Can't have a scalar return unless the return type is a "
4216 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4219 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
4220 // FIXME: This shouldn't require another copy.
4221 return EmitAggExprToLValue(E);
4224 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
4225 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
4226 && "binding l-value to type which needs a temporary");
4227 AggValueSlot Slot = CreateAggTemp(E->getType());
4228 EmitCXXConstructExpr(E, Slot);
4229 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4230 LValueBaseInfo(AlignmentSource::Decl, false));
4234 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
4235 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
4238 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
4239 return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
4240 ConvertType(E->getType()));
4243 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
4244 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4245 LValueBaseInfo(AlignmentSource::Decl, false));
4249 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
4250 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4251 Slot.setExternallyDestructed();
4252 EmitAggExpr(E->getSubExpr(), Slot);
4253 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4254 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4255 LValueBaseInfo(AlignmentSource::Decl, false));
4259 CodeGenFunction::EmitLambdaLValue(const LambdaExpr *E) {
4260 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4261 EmitLambdaExpr(E, Slot);
4262 return MakeAddrLValue(Slot.getAddress(), E->getType(),
4263 LValueBaseInfo(AlignmentSource::Decl, false));
4266 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
4267 RValue RV = EmitObjCMessageExpr(E);
4270 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4271 LValueBaseInfo(AlignmentSource::Decl, false));
4273 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4274 "Can't have a scalar return unless the return type is a "
4277 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4280 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
4282 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
4283 return MakeAddrLValue(V, E->getType(),
4284 LValueBaseInfo(AlignmentSource::Decl, false));
4287 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
4288 const ObjCIvarDecl *Ivar) {
4289 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4292 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
4293 llvm::Value *BaseValue,
4294 const ObjCIvarDecl *Ivar,
4295 unsigned CVRQualifiers) {
4296 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4297 Ivar, CVRQualifiers);
4300 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
4301 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4302 llvm::Value *BaseValue = nullptr;
4303 const Expr *BaseExpr = E->getBase();
4304 Qualifiers BaseQuals;
4307 BaseValue = EmitScalarExpr(BaseExpr);
4308 ObjectTy = BaseExpr->getType()->getPointeeType();
4309 BaseQuals = ObjectTy.getQualifiers();
4311 LValue BaseLV = EmitLValue(BaseExpr);
4312 BaseValue = BaseLV.getPointer();
4313 ObjectTy = BaseExpr->getType();
4314 BaseQuals = ObjectTy.getQualifiers();
4318 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4319 BaseQuals.getCVRQualifiers());
4320 setObjCGCLValueClass(getContext(), E, LV);
4324 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
4325 // Can only get l-value for message expression returning aggregate type
4326 RValue RV = EmitAnyExprToTemp(E);
4327 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4328 LValueBaseInfo(AlignmentSource::Decl, false));
4331 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4332 const CallExpr *E, ReturnValueSlot ReturnValue,
4333 llvm::Value *Chain) {
4334 // Get the actual function type. The callee type will always be a pointer to
4335 // function type or a block pointer type.
4336 assert(CalleeType->isFunctionPointerType() &&
4337 "Call must have function pointer type!");
4339 const Decl *TargetDecl = OrigCallee.getAbstractInfo().getCalleeDecl();
4341 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
4342 // We can only guarantee that a function is called from the correct
4343 // context/function based on the appropriate target attributes,
4344 // so only check in the case where we have both always_inline and target
4345 // since otherwise we could be making a conditional call after a check for
4346 // the proper cpu features (and it won't cause code generation issues due to
4347 // function based code generation).
4348 if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
4349 TargetDecl->hasAttr<TargetAttr>())
4350 checkTargetFeatures(E, FD);
4352 CalleeType = getContext().getCanonicalType(CalleeType);
4354 const auto *FnType =
4355 cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
4357 CGCallee Callee = OrigCallee;
4359 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4360 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4361 if (llvm::Constant *PrefixSig =
4362 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
4363 SanitizerScope SanScope(this);
4364 llvm::Constant *FTRTTIConst =
4365 CGM.GetAddrOfRTTIDescriptor(QualType(FnType, 0), /*ForEH=*/true);
4366 llvm::Type *PrefixStructTyElems[] = {
4367 PrefixSig->getType(),
4368 FTRTTIConst->getType()
4370 llvm::StructType *PrefixStructTy = llvm::StructType::get(
4371 CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4373 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4375 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4376 CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4377 llvm::Value *CalleeSigPtr =
4378 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4379 llvm::Value *CalleeSig =
4380 Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4381 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4383 llvm::BasicBlock *Cont = createBasicBlock("cont");
4384 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4385 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4387 EmitBlock(TypeCheck);
4388 llvm::Value *CalleeRTTIPtr =
4389 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4390 llvm::Value *CalleeRTTI =
4391 Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4392 llvm::Value *CalleeRTTIMatch =
4393 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4394 llvm::Constant *StaticData[] = {
4395 EmitCheckSourceLocation(E->getLocStart()),
4396 EmitCheckTypeDescriptor(CalleeType)
4398 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4399 SanitizerHandler::FunctionTypeMismatch, StaticData, CalleePtr);
4401 Builder.CreateBr(Cont);
4406 // If we are checking indirect calls and this call is indirect, check that the
4407 // function pointer is a member of the bit set for the function type.
4408 if (SanOpts.has(SanitizerKind::CFIICall) &&
4409 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4410 SanitizerScope SanScope(this);
4411 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4413 llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4414 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4416 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4417 llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4418 llvm::Value *TypeTest = Builder.CreateCall(
4419 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4421 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4422 llvm::Constant *StaticData[] = {
4423 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4424 EmitCheckSourceLocation(E->getLocStart()),
4425 EmitCheckTypeDescriptor(QualType(FnType, 0)),
4427 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4428 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4429 CastedCallee, StaticData);
4431 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4432 SanitizerHandler::CFICheckFail, StaticData,
4433 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4439 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
4440 CGM.getContext().VoidPtrTy);
4442 // C++17 requires that we evaluate arguments to a call using assignment syntax
4443 // right-to-left, and that we evaluate arguments to certain other operators
4444 // left-to-right. Note that we allow this to override the order dictated by
4445 // the calling convention on the MS ABI, which means that parameter
4446 // destruction order is not necessarily reverse construction order.
4447 // FIXME: Revisit this based on C++ committee response to unimplementability.
4448 EvaluationOrder Order = EvaluationOrder::Default;
4449 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4450 if (OCE->isAssignmentOp())
4451 Order = EvaluationOrder::ForceRightToLeft;
4453 switch (OCE->getOperator()) {
4455 case OO_GreaterGreater:
4460 Order = EvaluationOrder::ForceLeftToRight;
4468 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4469 E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4471 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
4472 Args, FnType, /*isChainCall=*/Chain);
4475 // If the expression that denotes the called function has a type
4476 // that does not include a prototype, [the default argument
4477 // promotions are performed]. If the number of arguments does not
4478 // equal the number of parameters, the behavior is undefined. If
4479 // the function is defined with a type that includes a prototype,
4480 // and either the prototype ends with an ellipsis (, ...) or the
4481 // types of the arguments after promotion are not compatible with
4482 // the types of the parameters, the behavior is undefined. If the
4483 // function is defined with a type that does not include a
4484 // prototype, and the types of the arguments after promotion are
4485 // not compatible with those of the parameters after promotion,
4486 // the behavior is undefined [except in some trivial cases].
4487 // That is, in the general case, we should assume that a call
4488 // through an unprototyped function type works like a *non-variadic*
4489 // call. The way we make this work is to cast to the exact type
4490 // of the promoted arguments.
4492 // Chain calls use this same code path to add the invisible chain parameter
4493 // to the function type.
4494 if (isa<FunctionNoProtoType>(FnType) || Chain) {
4495 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4496 CalleeTy = CalleeTy->getPointerTo();
4498 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4499 CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
4500 Callee.setFunctionPointer(CalleePtr);
4503 return EmitCall(FnInfo, Callee, ReturnValue, Args);
4506 LValue CodeGenFunction::
4507 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
4508 Address BaseAddr = Address::invalid();
4509 if (E->getOpcode() == BO_PtrMemI) {
4510 BaseAddr = EmitPointerWithAlignment(E->getLHS());
4512 BaseAddr = EmitLValue(E->getLHS()).getAddress();
4515 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4517 const MemberPointerType *MPT
4518 = E->getRHS()->getType()->getAs<MemberPointerType>();
4520 LValueBaseInfo BaseInfo;
4521 Address MemberAddr =
4522 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo);
4524 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo);
4527 /// Given the address of a temporary variable, produce an r-value of
4529 RValue CodeGenFunction::convertTempToRValue(Address addr,
4531 SourceLocation loc) {
4532 LValue lvalue = MakeAddrLValue(addr, type,
4533 LValueBaseInfo(AlignmentSource::Decl, false));
4534 switch (getEvaluationKind(type)) {
4536 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4538 return lvalue.asAggregateRValue();
4540 return RValue::get(EmitLoadOfScalar(lvalue, loc));
4542 llvm_unreachable("bad evaluation kind");
4545 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4546 assert(Val->getType()->isFPOrFPVectorTy());
4547 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4550 llvm::MDBuilder MDHelper(getLLVMContext());
4551 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
4553 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
4557 struct LValueOrRValue {
4563 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
4564 const PseudoObjectExpr *E,
4566 AggValueSlot slot) {
4567 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
4569 // Find the result expression, if any.
4570 const Expr *resultExpr = E->getResultExpr();
4571 LValueOrRValue result;
4573 for (PseudoObjectExpr::const_semantics_iterator
4574 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
4575 const Expr *semantic = *i;
4577 // If this semantic expression is an opaque value, bind it
4578 // to the result of its source expression.
4579 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
4581 // If this is the result expression, we may need to evaluate
4582 // directly into the slot.
4583 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
4585 if (ov == resultExpr && ov->isRValue() && !forLValue &&
4586 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
4587 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
4588 LValueBaseInfo BaseInfo(AlignmentSource::Decl, false);
4589 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
4591 opaqueData = OVMA::bind(CGF, ov, LV);
4592 result.RV = slot.asRValue();
4594 // Otherwise, emit as normal.
4596 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
4598 // If this is the result, also evaluate the result now.
4599 if (ov == resultExpr) {
4601 result.LV = CGF.EmitLValue(ov);
4603 result.RV = CGF.EmitAnyExpr(ov, slot);
4607 opaques.push_back(opaqueData);
4609 // Otherwise, if the expression is the result, evaluate it
4610 // and remember the result.
4611 } else if (semantic == resultExpr) {
4613 result.LV = CGF.EmitLValue(semantic);
4615 result.RV = CGF.EmitAnyExpr(semantic, slot);
4617 // Otherwise, evaluate the expression in an ignored context.
4619 CGF.EmitIgnoredExpr(semantic);
4623 // Unbind all the opaques now.
4624 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
4625 opaques[i].unbind(CGF);
4630 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
4631 AggValueSlot slot) {
4632 return emitPseudoObjectExpr(*this, E, false, slot).RV;
4635 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
4636 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;