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 //===----------------------------------------------------------------------===//
14 #include "CodeGenFunction.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "CGOpenMPRuntime.h"
20 #include "CGRecordLayout.h"
21 #include "CodeGenModule.h"
22 #include "TargetInfo.h"
23 #include "clang/AST/ASTContext.h"
24 #include "clang/AST/Attr.h"
25 #include "clang/AST/DeclObjC.h"
26 #include "clang/Frontend/CodeGenOptions.h"
27 #include "llvm/ADT/Hashing.h"
28 #include "llvm/ADT/StringExtras.h"
29 #include "llvm/IR/DataLayout.h"
30 #include "llvm/IR/Intrinsics.h"
31 #include "llvm/IR/LLVMContext.h"
32 #include "llvm/IR/MDBuilder.h"
33 #include "llvm/Support/ConvertUTF.h"
34 #include "llvm/Support/MathExtras.h"
35 #include "llvm/Support/Path.h"
36 #include "llvm/Transforms/Utils/SanitizerStats.h"
38 using namespace clang;
39 using namespace CodeGen;
41 //===--------------------------------------------------------------------===//
42 // Miscellaneous Helper Methods
43 //===--------------------------------------------------------------------===//
45 llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
46 unsigned addressSpace =
47 cast<llvm::PointerType>(value->getType())->getAddressSpace();
49 llvm::PointerType *destType = Int8PtrTy;
51 destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
53 if (value->getType() == destType) return value;
54 return Builder.CreateBitCast(value, destType);
57 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
59 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
61 auto Alloca = CreateTempAlloca(Ty, Name);
62 Alloca->setAlignment(Align.getQuantity());
63 return Address(Alloca, Align);
66 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
68 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
70 return new llvm::AllocaInst(Ty, nullptr, Name, AllocaInsertPt);
73 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
74 /// default alignment of the corresponding LLVM type, which is *not*
75 /// guaranteed to be related in any way to the expected alignment of
76 /// an AST type that might have been lowered to Ty.
77 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
80 CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
81 return CreateTempAlloca(Ty, Align, Name);
84 void CodeGenFunction::InitTempAlloca(Address Var, llvm::Value *Init) {
85 assert(isa<llvm::AllocaInst>(Var.getPointer()));
86 auto *Store = new llvm::StoreInst(Init, Var.getPointer());
87 Store->setAlignment(Var.getAlignment().getQuantity());
88 llvm::BasicBlock *Block = AllocaInsertPt->getParent();
89 Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
92 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
93 CharUnits Align = getContext().getTypeAlignInChars(Ty);
94 return CreateTempAlloca(ConvertType(Ty), Align, Name);
97 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name) {
98 // FIXME: Should we prefer the preferred type alignment here?
99 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name);
102 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
104 return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name);
107 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
108 /// expression and compare the result against zero, returning an Int1Ty value.
109 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
110 PGO.setCurrentStmt(E);
111 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
112 llvm::Value *MemPtr = EmitScalarExpr(E);
113 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
116 QualType BoolTy = getContext().BoolTy;
117 SourceLocation Loc = E->getExprLoc();
118 if (!E->getType()->isAnyComplexType())
119 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
121 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
125 /// EmitIgnoredExpr - Emit code to compute the specified expression,
126 /// ignoring the result.
127 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
129 return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
131 // Just emit it as an l-value and drop the result.
135 /// EmitAnyExpr - Emit code to compute the specified expression which
136 /// can have any type. The result is returned as an RValue struct.
137 /// If this is an aggregate expression, AggSlot indicates where the
138 /// result should be returned.
139 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
140 AggValueSlot aggSlot,
142 switch (getEvaluationKind(E->getType())) {
144 return RValue::get(EmitScalarExpr(E, ignoreResult));
146 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
148 if (!ignoreResult && aggSlot.isIgnored())
149 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
150 EmitAggExpr(E, aggSlot);
151 return aggSlot.asRValue();
153 llvm_unreachable("bad evaluation kind");
156 /// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will
157 /// always be accessible even if no aggregate location is provided.
158 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
159 AggValueSlot AggSlot = AggValueSlot::ignored();
161 if (hasAggregateEvaluationKind(E->getType()))
162 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
163 return EmitAnyExpr(E, AggSlot);
166 /// EmitAnyExprToMem - Evaluate an expression into a given memory
168 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
172 // FIXME: This function should take an LValue as an argument.
173 switch (getEvaluationKind(E->getType())) {
175 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
179 case TEK_Aggregate: {
180 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
181 AggValueSlot::IsDestructed_t(IsInit),
182 AggValueSlot::DoesNotNeedGCBarriers,
183 AggValueSlot::IsAliased_t(!IsInit)));
188 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
189 LValue LV = MakeAddrLValue(Location, E->getType());
190 EmitStoreThroughLValue(RV, LV);
194 llvm_unreachable("bad evaluation kind");
198 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
199 const Expr *E, Address ReferenceTemporary) {
200 // Objective-C++ ARC:
201 // If we are binding a reference to a temporary that has ownership, we
202 // need to perform retain/release operations on the temporary.
204 // FIXME: This should be looking at E, not M.
205 if (auto Lifetime = M->getType().getObjCLifetime()) {
207 case Qualifiers::OCL_None:
208 case Qualifiers::OCL_ExplicitNone:
209 // Carry on to normal cleanup handling.
212 case Qualifiers::OCL_Autoreleasing:
213 // Nothing to do; cleaned up by an autorelease pool.
216 case Qualifiers::OCL_Strong:
217 case Qualifiers::OCL_Weak:
218 switch (StorageDuration Duration = M->getStorageDuration()) {
220 // Note: we intentionally do not register a cleanup to release
221 // the object on program termination.
225 // FIXME: We should probably register a cleanup in this case.
229 case SD_FullExpression:
230 CodeGenFunction::Destroyer *Destroy;
231 CleanupKind CleanupKind;
232 if (Lifetime == Qualifiers::OCL_Strong) {
233 const ValueDecl *VD = M->getExtendingDecl();
235 VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
236 CleanupKind = CGF.getARCCleanupKind();
237 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
238 : &CodeGenFunction::destroyARCStrongImprecise;
240 // __weak objects always get EH cleanups; otherwise, exceptions
241 // could cause really nasty crashes instead of mere leaks.
242 CleanupKind = NormalAndEHCleanup;
243 Destroy = &CodeGenFunction::destroyARCWeak;
245 if (Duration == SD_FullExpression)
246 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
247 M->getType(), *Destroy,
248 CleanupKind & EHCleanup);
250 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
252 *Destroy, CleanupKind & EHCleanup);
256 llvm_unreachable("temporary cannot have dynamic storage duration");
258 llvm_unreachable("unknown storage duration");
262 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
263 if (const RecordType *RT =
264 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
265 // Get the destructor for the reference temporary.
266 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
267 if (!ClassDecl->hasTrivialDestructor())
268 ReferenceTemporaryDtor = ClassDecl->getDestructor();
271 if (!ReferenceTemporaryDtor)
274 // Call the destructor for the temporary.
275 switch (M->getStorageDuration()) {
278 llvm::Constant *CleanupFn;
279 llvm::Constant *CleanupArg;
280 if (E->getType()->isArrayType()) {
281 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
282 ReferenceTemporary, E->getType(),
283 CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
284 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
285 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
287 CleanupFn = CGF.CGM.getAddrOfCXXStructor(ReferenceTemporaryDtor,
288 StructorType::Complete);
289 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
291 CGF.CGM.getCXXABI().registerGlobalDtor(
292 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
296 case SD_FullExpression:
297 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
298 CodeGenFunction::destroyCXXObject,
299 CGF.getLangOpts().Exceptions);
303 CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
304 ReferenceTemporary, E->getType(),
305 CodeGenFunction::destroyCXXObject,
306 CGF.getLangOpts().Exceptions);
310 llvm_unreachable("temporary cannot have dynamic storage duration");
315 createReferenceTemporary(CodeGenFunction &CGF,
316 const MaterializeTemporaryExpr *M, const Expr *Inner) {
317 switch (M->getStorageDuration()) {
318 case SD_FullExpression:
320 // If we have a constant temporary array or record try to promote it into a
321 // constant global under the same rules a normal constant would've been
322 // promoted. This is easier on the optimizer and generally emits fewer
324 QualType Ty = Inner->getType();
325 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
326 (Ty->isArrayType() || Ty->isRecordType()) &&
327 CGF.CGM.isTypeConstant(Ty, true))
328 if (llvm::Constant *Init = CGF.CGM.EmitConstantExpr(Inner, Ty, &CGF)) {
329 auto *GV = new llvm::GlobalVariable(
330 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
331 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp");
332 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
333 GV->setAlignment(alignment.getQuantity());
334 // FIXME: Should we put the new global into a COMDAT?
335 return Address(GV, alignment);
337 return CGF.CreateMemTemp(Ty, "ref.tmp");
341 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
344 llvm_unreachable("temporary can't have dynamic storage duration");
346 llvm_unreachable("unknown storage duration");
349 LValue CodeGenFunction::
350 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
351 const Expr *E = M->GetTemporaryExpr();
353 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
354 // as that will cause the lifetime adjustment to be lost for ARC
355 auto ownership = M->getType().getObjCLifetime();
356 if (ownership != Qualifiers::OCL_None &&
357 ownership != Qualifiers::OCL_ExplicitNone) {
358 Address Object = createReferenceTemporary(*this, M, E);
359 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
360 Object = Address(llvm::ConstantExpr::getBitCast(Var,
361 ConvertTypeForMem(E->getType())
362 ->getPointerTo(Object.getAddressSpace())),
363 Object.getAlignment());
365 // createReferenceTemporary will promote the temporary to a global with a
366 // constant initializer if it can. It can only do this to a value of
367 // ARC-manageable type if the value is global and therefore "immune" to
368 // ref-counting operations. Therefore we have no need to emit either a
369 // dynamic initialization or a cleanup and we can just return the address
371 if (Var->hasInitializer())
372 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
374 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
376 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
377 AlignmentSource::Decl);
379 switch (getEvaluationKind(E->getType())) {
380 default: llvm_unreachable("expected scalar or aggregate expression");
382 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
384 case TEK_Aggregate: {
385 EmitAggExpr(E, AggValueSlot::forAddr(Object,
386 E->getType().getQualifiers(),
387 AggValueSlot::IsDestructed,
388 AggValueSlot::DoesNotNeedGCBarriers,
389 AggValueSlot::IsNotAliased));
394 pushTemporaryCleanup(*this, M, E, Object);
398 SmallVector<const Expr *, 2> CommaLHSs;
399 SmallVector<SubobjectAdjustment, 2> Adjustments;
400 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
402 for (const auto &Ignored : CommaLHSs)
403 EmitIgnoredExpr(Ignored);
405 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
406 if (opaque->getType()->isRecordType()) {
407 assert(Adjustments.empty());
408 return EmitOpaqueValueLValue(opaque);
412 // Create and initialize the reference temporary.
413 Address Object = createReferenceTemporary(*this, M, E);
414 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
415 Object = Address(llvm::ConstantExpr::getBitCast(
416 Var, ConvertTypeForMem(E->getType())->getPointerTo()),
417 Object.getAlignment());
418 // If the temporary is a global and has a constant initializer or is a
419 // constant temporary that we promoted to a global, we may have already
421 if (!Var->hasInitializer()) {
422 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
423 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
426 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
428 pushTemporaryCleanup(*this, M, E, Object);
430 // Perform derived-to-base casts and/or field accesses, to get from the
431 // temporary object we created (and, potentially, for which we extended
432 // the lifetime) to the subobject we're binding the reference to.
433 for (unsigned I = Adjustments.size(); I != 0; --I) {
434 SubobjectAdjustment &Adjustment = Adjustments[I-1];
435 switch (Adjustment.Kind) {
436 case SubobjectAdjustment::DerivedToBaseAdjustment:
438 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
439 Adjustment.DerivedToBase.BasePath->path_begin(),
440 Adjustment.DerivedToBase.BasePath->path_end(),
441 /*NullCheckValue=*/ false, E->getExprLoc());
444 case SubobjectAdjustment::FieldAdjustment: {
445 LValue LV = MakeAddrLValue(Object, E->getType(),
446 AlignmentSource::Decl);
447 LV = EmitLValueForField(LV, Adjustment.Field);
448 assert(LV.isSimple() &&
449 "materialized temporary field is not a simple lvalue");
450 Object = LV.getAddress();
454 case SubobjectAdjustment::MemberPointerAdjustment: {
455 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
456 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
463 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
467 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
468 // Emit the expression as an lvalue.
469 LValue LV = EmitLValue(E);
470 assert(LV.isSimple());
471 llvm::Value *Value = LV.getPointer();
473 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
474 // C++11 [dcl.ref]p5 (as amended by core issue 453):
475 // If a glvalue to which a reference is directly bound designates neither
476 // an existing object or function of an appropriate type nor a region of
477 // storage of suitable size and alignment to contain an object of the
478 // reference's type, the behavior is undefined.
479 QualType Ty = E->getType();
480 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
483 return RValue::get(Value);
487 /// getAccessedFieldNo - Given an encoded value and a result number, return the
488 /// input field number being accessed.
489 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
490 const llvm::Constant *Elts) {
491 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
495 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
496 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
498 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
499 llvm::Value *K47 = Builder.getInt64(47);
500 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
501 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
502 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
503 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
504 return Builder.CreateMul(B1, KMul);
507 bool CodeGenFunction::sanitizePerformTypeCheck() const {
508 return SanOpts.has(SanitizerKind::Null) |
509 SanOpts.has(SanitizerKind::Alignment) |
510 SanOpts.has(SanitizerKind::ObjectSize) |
511 SanOpts.has(SanitizerKind::Vptr);
514 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
515 llvm::Value *Ptr, QualType Ty,
516 CharUnits Alignment, bool SkipNullCheck) {
517 if (!sanitizePerformTypeCheck())
520 // Don't check pointers outside the default address space. The null check
521 // isn't correct, the object-size check isn't supported by LLVM, and we can't
522 // communicate the addresses to the runtime handler for the vptr check.
523 if (Ptr->getType()->getPointerAddressSpace())
526 SanitizerScope SanScope(this);
528 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
529 llvm::BasicBlock *Done = nullptr;
531 bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
532 TCK == TCK_UpcastToVirtualBase;
533 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
535 // The glvalue must not be an empty glvalue.
536 llvm::Value *IsNonNull = Builder.CreateIsNotNull(Ptr);
538 if (AllowNullPointers) {
539 // When performing pointer casts, it's OK if the value is null.
540 // Skip the remaining checks in that case.
541 Done = createBasicBlock("null");
542 llvm::BasicBlock *Rest = createBasicBlock("not.null");
543 Builder.CreateCondBr(IsNonNull, Rest, Done);
546 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
550 if (SanOpts.has(SanitizerKind::ObjectSize) && !Ty->isIncompleteType()) {
551 uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
553 // The glvalue must refer to a large enough storage region.
554 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
556 // FIXME: Get object address space
557 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
558 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
559 llvm::Value *Min = Builder.getFalse();
560 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
561 llvm::Value *LargeEnough =
562 Builder.CreateICmpUGE(Builder.CreateCall(F, {CastAddr, Min}),
563 llvm::ConstantInt::get(IntPtrTy, Size));
564 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
567 uint64_t AlignVal = 0;
569 if (SanOpts.has(SanitizerKind::Alignment)) {
570 AlignVal = Alignment.getQuantity();
571 if (!Ty->isIncompleteType() && !AlignVal)
572 AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
574 // The glvalue must be suitably aligned.
577 Builder.CreateAnd(Builder.CreatePtrToInt(Ptr, IntPtrTy),
578 llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
579 llvm::Value *Aligned =
580 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
581 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
585 if (Checks.size() > 0) {
586 llvm::Constant *StaticData[] = {
587 EmitCheckSourceLocation(Loc),
588 EmitCheckTypeDescriptor(Ty),
589 llvm::ConstantInt::get(SizeTy, AlignVal),
590 llvm::ConstantInt::get(Int8Ty, TCK)
592 EmitCheck(Checks, "type_mismatch", StaticData, Ptr);
595 // If possible, check that the vptr indicates that there is a subobject of
596 // type Ty at offset zero within this object.
598 // C++11 [basic.life]p5,6:
599 // [For storage which does not refer to an object within its lifetime]
600 // The program has undefined behavior if:
601 // -- the [pointer or glvalue] is used to access a non-static data member
602 // or call a non-static member function
603 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
604 if (SanOpts.has(SanitizerKind::Vptr) &&
605 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
606 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
607 TCK == TCK_UpcastToVirtualBase) &&
608 RD && RD->hasDefinition() && RD->isDynamicClass()) {
609 // Compute a hash of the mangled name of the type.
611 // FIXME: This is not guaranteed to be deterministic! Move to a
612 // fingerprinting mechanism once LLVM provides one. For the time
613 // being the implementation happens to be deterministic.
614 SmallString<64> MangledName;
615 llvm::raw_svector_ostream Out(MangledName);
616 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
619 // Blacklist based on the mangled type.
620 if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
622 llvm::hash_code TypeHash = hash_value(Out.str());
624 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
625 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
626 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
627 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
628 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
629 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
631 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
632 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
634 // Look the hash up in our cache.
635 const int CacheSize = 128;
636 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
637 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
638 "__ubsan_vptr_type_cache");
639 llvm::Value *Slot = Builder.CreateAnd(Hash,
640 llvm::ConstantInt::get(IntPtrTy,
642 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
643 llvm::Value *CacheVal =
644 Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
647 // If the hash isn't in the cache, call a runtime handler to perform the
648 // hard work of checking whether the vptr is for an object of the right
649 // type. This will either fill in the cache and return, or produce a
651 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
652 llvm::Constant *StaticData[] = {
653 EmitCheckSourceLocation(Loc),
654 EmitCheckTypeDescriptor(Ty),
655 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
656 llvm::ConstantInt::get(Int8Ty, TCK)
658 llvm::Value *DynamicData[] = { Ptr, Hash };
659 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
660 "dynamic_type_cache_miss", StaticData, DynamicData);
665 Builder.CreateBr(Done);
670 /// Determine whether this expression refers to a flexible array member in a
671 /// struct. We disable array bounds checks for such members.
672 static bool isFlexibleArrayMemberExpr(const Expr *E) {
673 // For compatibility with existing code, we treat arrays of length 0 or
674 // 1 as flexible array members.
675 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
676 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
677 if (CAT->getSize().ugt(1))
679 } else if (!isa<IncompleteArrayType>(AT))
682 E = E->IgnoreParens();
684 // A flexible array member must be the last member in the class.
685 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
686 // FIXME: If the base type of the member expr is not FD->getParent(),
687 // this should not be treated as a flexible array member access.
688 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
689 RecordDecl::field_iterator FI(
690 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
691 return ++FI == FD->getParent()->field_end();
698 /// If Base is known to point to the start of an array, return the length of
699 /// that array. Return 0 if the length cannot be determined.
700 static llvm::Value *getArrayIndexingBound(
701 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
702 // For the vector indexing extension, the bound is the number of elements.
703 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
704 IndexedType = Base->getType();
705 return CGF.Builder.getInt32(VT->getNumElements());
708 Base = Base->IgnoreParens();
710 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
711 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
712 !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
713 IndexedType = CE->getSubExpr()->getType();
714 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
715 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
716 return CGF.Builder.getInt(CAT->getSize());
717 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
718 return CGF.getVLASize(VAT).first;
725 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
726 llvm::Value *Index, QualType IndexType,
728 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
729 "should not be called unless adding bounds checks");
730 SanitizerScope SanScope(this);
732 QualType IndexedType;
733 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
737 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
738 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
739 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
741 llvm::Constant *StaticData[] = {
742 EmitCheckSourceLocation(E->getExprLoc()),
743 EmitCheckTypeDescriptor(IndexedType),
744 EmitCheckTypeDescriptor(IndexType)
746 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
747 : Builder.CreateICmpULE(IndexVal, BoundVal);
748 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds), "out_of_bounds",
753 CodeGenFunction::ComplexPairTy CodeGenFunction::
754 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
755 bool isInc, bool isPre) {
756 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
758 llvm::Value *NextVal;
759 if (isa<llvm::IntegerType>(InVal.first->getType())) {
760 uint64_t AmountVal = isInc ? 1 : -1;
761 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
763 // Add the inc/dec to the real part.
764 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
766 QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
767 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
770 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
772 // Add the inc/dec to the real part.
773 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
776 ComplexPairTy IncVal(NextVal, InVal.second);
778 // Store the updated result through the lvalue.
779 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
781 // If this is a postinc, return the value read from memory, otherwise use the
783 return isPre ? IncVal : InVal;
786 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
787 CodeGenFunction *CGF) {
788 // Bind VLAs in the cast type.
789 if (CGF && E->getType()->isVariablyModifiedType())
790 CGF->EmitVariablyModifiedType(E->getType());
792 if (CGDebugInfo *DI = getModuleDebugInfo())
793 DI->EmitExplicitCastType(E->getType());
796 //===----------------------------------------------------------------------===//
797 // LValue Expression Emission
798 //===----------------------------------------------------------------------===//
800 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
801 /// derive a more accurate bound on the alignment of the pointer.
802 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
803 AlignmentSource *Source) {
804 // We allow this with ObjC object pointers because of fragile ABIs.
805 assert(E->getType()->isPointerType() ||
806 E->getType()->isObjCObjectPointerType());
807 E = E->IgnoreParens();
810 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
811 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
812 CGM.EmitExplicitCastExprType(ECE, this);
814 switch (CE->getCastKind()) {
815 // Non-converting casts (but not C's implicit conversion from void*).
818 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
819 if (PtrTy->getPointeeType()->isVoidType())
822 AlignmentSource InnerSource;
823 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), &InnerSource);
824 if (Source) *Source = InnerSource;
826 // If this is an explicit bitcast, and the source l-value is
827 // opaque, honor the alignment of the casted-to type.
828 if (isa<ExplicitCastExpr>(CE) &&
829 InnerSource != AlignmentSource::Decl) {
830 Addr = Address(Addr.getPointer(),
831 getNaturalPointeeTypeAlignment(E->getType(), Source));
834 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
835 CE->getCastKind() == CK_BitCast) {
836 if (auto PT = E->getType()->getAs<PointerType>())
837 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
839 CodeGenFunction::CFITCK_UnrelatedCast,
843 return Builder.CreateBitCast(Addr, ConvertType(E->getType()));
847 // Array-to-pointer decay.
848 case CK_ArrayToPointerDecay:
849 return EmitArrayToPointerDecay(CE->getSubExpr(), Source);
851 // Derived-to-base conversions.
852 case CK_UncheckedDerivedToBase:
853 case CK_DerivedToBase: {
854 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), Source);
855 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
856 return GetAddressOfBaseClass(Addr, Derived,
857 CE->path_begin(), CE->path_end(),
858 ShouldNullCheckClassCastValue(CE),
862 // TODO: Is there any reason to treat base-to-derived conversions
870 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
871 if (UO->getOpcode() == UO_AddrOf) {
872 LValue LV = EmitLValue(UO->getSubExpr());
873 if (Source) *Source = LV.getAlignmentSource();
874 return LV.getAddress();
878 // TODO: conditional operators, comma.
880 // Otherwise, use the alignment of the type.
881 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), Source);
882 return Address(EmitScalarExpr(E), Align);
885 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
886 if (Ty->isVoidType())
887 return RValue::get(nullptr);
889 switch (getEvaluationKind(Ty)) {
892 ConvertType(Ty->castAs<ComplexType>()->getElementType());
893 llvm::Value *U = llvm::UndefValue::get(EltTy);
894 return RValue::getComplex(std::make_pair(U, U));
897 // If this is a use of an undefined aggregate type, the aggregate must have an
898 // identifiable address. Just because the contents of the value are undefined
899 // doesn't mean that the address can't be taken and compared.
900 case TEK_Aggregate: {
901 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
902 return RValue::getAggregate(DestPtr);
906 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
908 llvm_unreachable("bad evaluation kind");
911 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
913 ErrorUnsupported(E, Name);
914 return GetUndefRValue(E->getType());
917 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
919 ErrorUnsupported(E, Name);
920 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
921 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
925 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
927 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
928 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
931 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
932 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
933 E->getType(), LV.getAlignment());
937 /// EmitLValue - Emit code to compute a designator that specifies the location
938 /// of the expression.
940 /// This can return one of two things: a simple address or a bitfield reference.
941 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
942 /// an LLVM pointer type.
944 /// If this returns a bitfield reference, nothing about the pointee type of the
945 /// LLVM value is known: For example, it may not be a pointer to an integer.
947 /// If this returns a normal address, and if the lvalue's C type is fixed size,
948 /// this method guarantees that the returned pointer type will point to an LLVM
949 /// type of the same size of the lvalue's type. If the lvalue has a variable
950 /// length type, this is not possible.
952 LValue CodeGenFunction::EmitLValue(const Expr *E) {
953 ApplyDebugLocation DL(*this, E);
954 switch (E->getStmtClass()) {
955 default: return EmitUnsupportedLValue(E, "l-value expression");
957 case Expr::ObjCPropertyRefExprClass:
958 llvm_unreachable("cannot emit a property reference directly");
960 case Expr::ObjCSelectorExprClass:
961 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
962 case Expr::ObjCIsaExprClass:
963 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
964 case Expr::BinaryOperatorClass:
965 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
966 case Expr::CompoundAssignOperatorClass: {
967 QualType Ty = E->getType();
968 if (const AtomicType *AT = Ty->getAs<AtomicType>())
969 Ty = AT->getValueType();
970 if (!Ty->isAnyComplexType())
971 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
972 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
974 case Expr::CallExprClass:
975 case Expr::CXXMemberCallExprClass:
976 case Expr::CXXOperatorCallExprClass:
977 case Expr::UserDefinedLiteralClass:
978 return EmitCallExprLValue(cast<CallExpr>(E));
979 case Expr::VAArgExprClass:
980 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
981 case Expr::DeclRefExprClass:
982 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
983 case Expr::ParenExprClass:
984 return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
985 case Expr::GenericSelectionExprClass:
986 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
987 case Expr::PredefinedExprClass:
988 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
989 case Expr::StringLiteralClass:
990 return EmitStringLiteralLValue(cast<StringLiteral>(E));
991 case Expr::ObjCEncodeExprClass:
992 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
993 case Expr::PseudoObjectExprClass:
994 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
995 case Expr::InitListExprClass:
996 return EmitInitListLValue(cast<InitListExpr>(E));
997 case Expr::CXXTemporaryObjectExprClass:
998 case Expr::CXXConstructExprClass:
999 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1000 case Expr::CXXBindTemporaryExprClass:
1001 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1002 case Expr::CXXUuidofExprClass:
1003 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1004 case Expr::LambdaExprClass:
1005 return EmitLambdaLValue(cast<LambdaExpr>(E));
1007 case Expr::ExprWithCleanupsClass: {
1008 const auto *cleanups = cast<ExprWithCleanups>(E);
1009 enterFullExpression(cleanups);
1010 RunCleanupsScope Scope(*this);
1011 return EmitLValue(cleanups->getSubExpr());
1014 case Expr::CXXDefaultArgExprClass:
1015 return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1016 case Expr::CXXDefaultInitExprClass: {
1017 CXXDefaultInitExprScope Scope(*this);
1018 return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1020 case Expr::CXXTypeidExprClass:
1021 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1023 case Expr::ObjCMessageExprClass:
1024 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1025 case Expr::ObjCIvarRefExprClass:
1026 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1027 case Expr::StmtExprClass:
1028 return EmitStmtExprLValue(cast<StmtExpr>(E));
1029 case Expr::UnaryOperatorClass:
1030 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1031 case Expr::ArraySubscriptExprClass:
1032 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1033 case Expr::OMPArraySectionExprClass:
1034 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1035 case Expr::ExtVectorElementExprClass:
1036 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1037 case Expr::MemberExprClass:
1038 return EmitMemberExpr(cast<MemberExpr>(E));
1039 case Expr::CompoundLiteralExprClass:
1040 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1041 case Expr::ConditionalOperatorClass:
1042 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1043 case Expr::BinaryConditionalOperatorClass:
1044 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1045 case Expr::ChooseExprClass:
1046 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1047 case Expr::OpaqueValueExprClass:
1048 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1049 case Expr::SubstNonTypeTemplateParmExprClass:
1050 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1051 case Expr::ImplicitCastExprClass:
1052 case Expr::CStyleCastExprClass:
1053 case Expr::CXXFunctionalCastExprClass:
1054 case Expr::CXXStaticCastExprClass:
1055 case Expr::CXXDynamicCastExprClass:
1056 case Expr::CXXReinterpretCastExprClass:
1057 case Expr::CXXConstCastExprClass:
1058 case Expr::ObjCBridgedCastExprClass:
1059 return EmitCastLValue(cast<CastExpr>(E));
1061 case Expr::MaterializeTemporaryExprClass:
1062 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1066 /// Given an object of the given canonical type, can we safely copy a
1067 /// value out of it based on its initializer?
1068 static bool isConstantEmittableObjectType(QualType type) {
1069 assert(type.isCanonical());
1070 assert(!type->isReferenceType());
1072 // Must be const-qualified but non-volatile.
1073 Qualifiers qs = type.getLocalQualifiers();
1074 if (!qs.hasConst() || qs.hasVolatile()) return false;
1076 // Otherwise, all object types satisfy this except C++ classes with
1077 // mutable subobjects or non-trivial copy/destroy behavior.
1078 if (const auto *RT = dyn_cast<RecordType>(type))
1079 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1080 if (RD->hasMutableFields() || !RD->isTrivial())
1086 /// Can we constant-emit a load of a reference to a variable of the
1087 /// given type? This is different from predicates like
1088 /// Decl::isUsableInConstantExpressions because we do want it to apply
1089 /// in situations that don't necessarily satisfy the language's rules
1090 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1091 /// to do this with const float variables even if those variables
1092 /// aren't marked 'constexpr'.
1093 enum ConstantEmissionKind {
1095 CEK_AsReferenceOnly,
1096 CEK_AsValueOrReference,
1099 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1100 type = type.getCanonicalType();
1101 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1102 if (isConstantEmittableObjectType(ref->getPointeeType()))
1103 return CEK_AsValueOrReference;
1104 return CEK_AsReferenceOnly;
1106 if (isConstantEmittableObjectType(type))
1107 return CEK_AsValueOnly;
1111 /// Try to emit a reference to the given value without producing it as
1112 /// an l-value. This is actually more than an optimization: we can't
1113 /// produce an l-value for variables that we never actually captured
1114 /// in a block or lambda, which means const int variables or constexpr
1115 /// literals or similar.
1116 CodeGenFunction::ConstantEmission
1117 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1118 ValueDecl *value = refExpr->getDecl();
1120 // The value needs to be an enum constant or a constant variable.
1121 ConstantEmissionKind CEK;
1122 if (isa<ParmVarDecl>(value)) {
1124 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1125 CEK = checkVarTypeForConstantEmission(var->getType());
1126 } else if (isa<EnumConstantDecl>(value)) {
1127 CEK = CEK_AsValueOnly;
1131 if (CEK == CEK_None) return ConstantEmission();
1133 Expr::EvalResult result;
1134 bool resultIsReference;
1135 QualType resultType;
1137 // It's best to evaluate all the way as an r-value if that's permitted.
1138 if (CEK != CEK_AsReferenceOnly &&
1139 refExpr->EvaluateAsRValue(result, getContext())) {
1140 resultIsReference = false;
1141 resultType = refExpr->getType();
1143 // Otherwise, try to evaluate as an l-value.
1144 } else if (CEK != CEK_AsValueOnly &&
1145 refExpr->EvaluateAsLValue(result, getContext())) {
1146 resultIsReference = true;
1147 resultType = value->getType();
1151 return ConstantEmission();
1154 // In any case, if the initializer has side-effects, abandon ship.
1155 if (result.HasSideEffects)
1156 return ConstantEmission();
1158 // Emit as a constant.
1159 llvm::Constant *C = CGM.EmitConstantValue(result.Val, resultType, this);
1161 // Make sure we emit a debug reference to the global variable.
1162 // This should probably fire even for
1163 if (isa<VarDecl>(value)) {
1164 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1165 EmitDeclRefExprDbgValue(refExpr, C);
1167 assert(isa<EnumConstantDecl>(value));
1168 EmitDeclRefExprDbgValue(refExpr, C);
1171 // If we emitted a reference constant, we need to dereference that.
1172 if (resultIsReference)
1173 return ConstantEmission::forReference(C);
1175 return ConstantEmission::forValue(C);
1178 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1179 SourceLocation Loc) {
1180 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1181 lvalue.getType(), Loc, lvalue.getAlignmentSource(),
1182 lvalue.getTBAAInfo(),
1183 lvalue.getTBAABaseType(), lvalue.getTBAAOffset(),
1184 lvalue.isNontemporal());
1187 static bool hasBooleanRepresentation(QualType Ty) {
1188 if (Ty->isBooleanType())
1191 if (const EnumType *ET = Ty->getAs<EnumType>())
1192 return ET->getDecl()->getIntegerType()->isBooleanType();
1194 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1195 return hasBooleanRepresentation(AT->getValueType());
1200 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1201 llvm::APInt &Min, llvm::APInt &End,
1203 const EnumType *ET = Ty->getAs<EnumType>();
1204 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1205 ET && !ET->getDecl()->isFixed();
1206 bool IsBool = hasBooleanRepresentation(Ty);
1207 if (!IsBool && !IsRegularCPlusPlusEnum)
1211 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1212 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1214 const EnumDecl *ED = ET->getDecl();
1215 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1216 unsigned Bitwidth = LTy->getScalarSizeInBits();
1217 unsigned NumNegativeBits = ED->getNumNegativeBits();
1218 unsigned NumPositiveBits = ED->getNumPositiveBits();
1220 if (NumNegativeBits) {
1221 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1222 assert(NumBits <= Bitwidth);
1223 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1226 assert(NumPositiveBits <= Bitwidth);
1227 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1228 Min = llvm::APInt(Bitwidth, 0);
1234 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1235 llvm::APInt Min, End;
1236 if (!getRangeForType(*this, Ty, Min, End,
1237 CGM.getCodeGenOpts().StrictEnums))
1240 llvm::MDBuilder MDHelper(getLLVMContext());
1241 return MDHelper.createRange(Min, End);
1244 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1247 AlignmentSource AlignSource,
1248 llvm::MDNode *TBAAInfo,
1249 QualType TBAABaseType,
1250 uint64_t TBAAOffset,
1251 bool isNontemporal) {
1252 // For better performance, handle vector loads differently.
1253 if (Ty->isVectorType()) {
1254 const llvm::Type *EltTy = Addr.getElementType();
1256 const auto *VTy = cast<llvm::VectorType>(EltTy);
1258 // Handle vectors of size 3 like size 4 for better performance.
1259 if (VTy->getNumElements() == 3) {
1261 // Bitcast to vec4 type.
1262 llvm::VectorType *vec4Ty = llvm::VectorType::get(VTy->getElementType(),
1264 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1266 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1268 // Shuffle vector to get vec3.
1269 V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1270 {0, 1, 2}, "extractVec");
1271 return EmitFromMemory(V, Ty);
1275 // Atomic operations have to be done on integral types.
1276 LValue AtomicLValue =
1277 LValue::MakeAddr(Addr, Ty, getContext(), AlignSource, TBAAInfo);
1278 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1279 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1282 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1283 if (isNontemporal) {
1284 llvm::MDNode *Node = llvm::MDNode::get(
1285 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1286 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1289 llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
1292 CGM.DecorateInstructionWithTBAA(Load, TBAAPath,
1293 false /*ConvertTypeToTag*/);
1296 bool NeedsBoolCheck =
1297 SanOpts.has(SanitizerKind::Bool) && hasBooleanRepresentation(Ty);
1298 bool NeedsEnumCheck =
1299 SanOpts.has(SanitizerKind::Enum) && Ty->getAs<EnumType>();
1300 if (NeedsBoolCheck || NeedsEnumCheck) {
1301 SanitizerScope SanScope(this);
1302 llvm::APInt Min, End;
1303 if (getRangeForType(*this, Ty, Min, End, true)) {
1307 Check = Builder.CreateICmpULE(
1308 Load, llvm::ConstantInt::get(getLLVMContext(), End));
1310 llvm::Value *Upper = Builder.CreateICmpSLE(
1311 Load, llvm::ConstantInt::get(getLLVMContext(), End));
1312 llvm::Value *Lower = Builder.CreateICmpSGE(
1313 Load, llvm::ConstantInt::get(getLLVMContext(), Min));
1314 Check = Builder.CreateAnd(Upper, Lower);
1316 llvm::Constant *StaticArgs[] = {
1317 EmitCheckSourceLocation(Loc),
1318 EmitCheckTypeDescriptor(Ty)
1320 SanitizerMask Kind = NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1321 EmitCheck(std::make_pair(Check, Kind), "load_invalid_value", StaticArgs,
1322 EmitCheckValue(Load));
1324 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1325 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1326 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1328 return EmitFromMemory(Load, Ty);
1331 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1332 // Bool has a different representation in memory than in registers.
1333 if (hasBooleanRepresentation(Ty)) {
1334 // This should really always be an i1, but sometimes it's already
1335 // an i8, and it's awkward to track those cases down.
1336 if (Value->getType()->isIntegerTy(1))
1337 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1338 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1339 "wrong value rep of bool");
1345 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1346 // Bool has a different representation in memory than in registers.
1347 if (hasBooleanRepresentation(Ty)) {
1348 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1349 "wrong value rep of bool");
1350 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1356 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1357 bool Volatile, QualType Ty,
1358 AlignmentSource AlignSource,
1359 llvm::MDNode *TBAAInfo,
1360 bool isInit, QualType TBAABaseType,
1361 uint64_t TBAAOffset,
1362 bool isNontemporal) {
1364 // Handle vectors differently to get better performance.
1365 if (Ty->isVectorType()) {
1366 llvm::Type *SrcTy = Value->getType();
1367 auto *VecTy = cast<llvm::VectorType>(SrcTy);
1368 // Handle vec3 special.
1369 if (VecTy->getNumElements() == 3) {
1370 // Our source is a vec3, do a shuffle vector to make it a vec4.
1371 llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1372 Builder.getInt32(2),
1373 llvm::UndefValue::get(Builder.getInt32Ty())};
1374 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1375 Value = Builder.CreateShuffleVector(Value,
1376 llvm::UndefValue::get(VecTy),
1377 MaskV, "extractVec");
1378 SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1380 if (Addr.getElementType() != SrcTy) {
1381 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1385 Value = EmitToMemory(Value, Ty);
1387 LValue AtomicLValue =
1388 LValue::MakeAddr(Addr, Ty, getContext(), AlignSource, TBAAInfo);
1389 if (Ty->isAtomicType() ||
1390 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1391 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1395 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1396 if (isNontemporal) {
1397 llvm::MDNode *Node =
1398 llvm::MDNode::get(Store->getContext(),
1399 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1400 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1403 llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
1406 CGM.DecorateInstructionWithTBAA(Store, TBAAPath,
1407 false /*ConvertTypeToTag*/);
1411 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1413 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1414 lvalue.getType(), lvalue.getAlignmentSource(),
1415 lvalue.getTBAAInfo(), isInit, lvalue.getTBAABaseType(),
1416 lvalue.getTBAAOffset(), lvalue.isNontemporal());
1419 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1420 /// method emits the address of the lvalue, then loads the result as an rvalue,
1421 /// returning the rvalue.
1422 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1423 if (LV.isObjCWeak()) {
1424 // load of a __weak object.
1425 Address AddrWeakObj = LV.getAddress();
1426 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1429 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1430 // In MRC mode, we do a load+autorelease.
1431 if (!getLangOpts().ObjCAutoRefCount) {
1432 return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1435 // In ARC mode, we load retained and then consume the value.
1436 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
1437 Object = EmitObjCConsumeObject(LV.getType(), Object);
1438 return RValue::get(Object);
1441 if (LV.isSimple()) {
1442 assert(!LV.getType()->isFunctionType());
1444 // Everything needs a load.
1445 return RValue::get(EmitLoadOfScalar(LV, Loc));
1448 if (LV.isVectorElt()) {
1449 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1450 LV.isVolatileQualified());
1451 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1455 // If this is a reference to a subset of the elements of a vector, either
1456 // shuffle the input or extract/insert them as appropriate.
1457 if (LV.isExtVectorElt())
1458 return EmitLoadOfExtVectorElementLValue(LV);
1460 // Global Register variables always invoke intrinsics
1461 if (LV.isGlobalReg())
1462 return EmitLoadOfGlobalRegLValue(LV);
1464 assert(LV.isBitField() && "Unknown LValue type!");
1465 return EmitLoadOfBitfieldLValue(LV);
1468 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV) {
1469 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1471 // Get the output type.
1472 llvm::Type *ResLTy = ConvertType(LV.getType());
1474 Address Ptr = LV.getBitFieldAddress();
1475 llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1477 if (Info.IsSigned) {
1478 assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1479 unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1481 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1482 if (Info.Offset + HighBits)
1483 Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1486 Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1487 if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1488 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1492 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1494 return RValue::get(Val);
1497 // If this is a reference to a subset of the elements of a vector, create an
1498 // appropriate shufflevector.
1499 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1500 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1501 LV.isVolatileQualified());
1503 const llvm::Constant *Elts = LV.getExtVectorElts();
1505 // If the result of the expression is a non-vector type, we must be extracting
1506 // a single element. Just codegen as an extractelement.
1507 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1509 unsigned InIdx = getAccessedFieldNo(0, Elts);
1510 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1511 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1514 // Always use shuffle vector to try to retain the original program structure
1515 unsigned NumResultElts = ExprVT->getNumElements();
1517 SmallVector<llvm::Constant*, 4> Mask;
1518 for (unsigned i = 0; i != NumResultElts; ++i)
1519 Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1521 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1522 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1524 return RValue::get(Vec);
1527 /// @brief Generates lvalue for partial ext_vector access.
1528 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
1529 Address VectorAddress = LV.getExtVectorAddress();
1530 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1531 QualType EQT = ExprVT->getElementType();
1532 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1534 Address CastToPointerElement =
1535 Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1536 "conv.ptr.element");
1538 const llvm::Constant *Elts = LV.getExtVectorElts();
1539 unsigned ix = getAccessedFieldNo(0, Elts);
1541 Address VectorBasePtrPlusIx =
1542 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1543 getContext().getTypeSizeInChars(EQT),
1546 return VectorBasePtrPlusIx;
1549 /// @brief Load of global gamed gegisters are always calls to intrinsics.
1550 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
1551 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1552 "Bad type for register variable");
1553 llvm::MDNode *RegName = cast<llvm::MDNode>(
1554 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1556 // We accept integer and pointer types only
1557 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1558 llvm::Type *Ty = OrigTy;
1559 if (OrigTy->isPointerTy())
1560 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1561 llvm::Type *Types[] = { Ty };
1563 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1564 llvm::Value *Call = Builder.CreateCall(
1565 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1566 if (OrigTy->isPointerTy())
1567 Call = Builder.CreateIntToPtr(Call, OrigTy);
1568 return RValue::get(Call);
1572 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1573 /// lvalue, where both are guaranteed to the have the same type, and that type
1575 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
1577 if (!Dst.isSimple()) {
1578 if (Dst.isVectorElt()) {
1579 // Read/modify/write the vector, inserting the new element.
1580 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
1581 Dst.isVolatileQualified());
1582 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1583 Dst.getVectorIdx(), "vecins");
1584 Builder.CreateStore(Vec, Dst.getVectorAddress(),
1585 Dst.isVolatileQualified());
1589 // If this is an update of extended vector elements, insert them as
1591 if (Dst.isExtVectorElt())
1592 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
1594 if (Dst.isGlobalReg())
1595 return EmitStoreThroughGlobalRegLValue(Src, Dst);
1597 assert(Dst.isBitField() && "Unknown LValue type");
1598 return EmitStoreThroughBitfieldLValue(Src, Dst);
1601 // There's special magic for assigning into an ARC-qualified l-value.
1602 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1604 case Qualifiers::OCL_None:
1605 llvm_unreachable("present but none");
1607 case Qualifiers::OCL_ExplicitNone:
1611 case Qualifiers::OCL_Strong:
1612 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1615 case Qualifiers::OCL_Weak:
1616 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1619 case Qualifiers::OCL_Autoreleasing:
1620 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
1621 Src.getScalarVal()));
1622 // fall into the normal path
1627 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1628 // load of a __weak object.
1629 Address LvalueDst = Dst.getAddress();
1630 llvm::Value *src = Src.getScalarVal();
1631 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1635 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1636 // load of a __strong object.
1637 Address LvalueDst = Dst.getAddress();
1638 llvm::Value *src = Src.getScalarVal();
1639 if (Dst.isObjCIvar()) {
1640 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1641 llvm::Type *ResultType = IntPtrTy;
1642 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
1643 llvm::Value *RHS = dst.getPointer();
1644 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1646 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1647 "sub.ptr.lhs.cast");
1648 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
1649 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1651 } else if (Dst.isGlobalObjCRef()) {
1652 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1653 Dst.isThreadLocalRef());
1656 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1660 assert(Src.isScalar() && "Can't emit an agg store with this method");
1661 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
1664 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
1665 llvm::Value **Result) {
1666 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1667 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1668 Address Ptr = Dst.getBitFieldAddress();
1670 // Get the source value, truncated to the width of the bit-field.
1671 llvm::Value *SrcVal = Src.getScalarVal();
1673 // Cast the source to the storage type and shift it into place.
1674 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
1675 /*IsSigned=*/false);
1676 llvm::Value *MaskedVal = SrcVal;
1678 // See if there are other bits in the bitfield's storage we'll need to load
1679 // and mask together with source before storing.
1680 if (Info.StorageSize != Info.Size) {
1681 assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
1683 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
1685 // Mask the source value as needed.
1686 if (!hasBooleanRepresentation(Dst.getType()))
1687 SrcVal = Builder.CreateAnd(SrcVal,
1688 llvm::APInt::getLowBitsSet(Info.StorageSize,
1693 SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
1695 // Mask out the original value.
1696 Val = Builder.CreateAnd(Val,
1697 ~llvm::APInt::getBitsSet(Info.StorageSize,
1699 Info.Offset + Info.Size),
1702 // Or together the unchanged values and the source value.
1703 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
1705 assert(Info.Offset == 0);
1708 // Write the new value back out.
1709 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
1711 // Return the new value of the bit-field, if requested.
1713 llvm::Value *ResultVal = MaskedVal;
1715 // Sign extend the value if needed.
1716 if (Info.IsSigned) {
1717 assert(Info.Size <= Info.StorageSize);
1718 unsigned HighBits = Info.StorageSize - Info.Size;
1720 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
1721 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
1725 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
1727 *Result = EmitFromMemory(ResultVal, Dst.getType());
1731 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
1733 // This access turns into a read/modify/write of the vector. Load the input
1735 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
1736 Dst.isVolatileQualified());
1737 const llvm::Constant *Elts = Dst.getExtVectorElts();
1739 llvm::Value *SrcVal = Src.getScalarVal();
1741 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
1742 unsigned NumSrcElts = VTy->getNumElements();
1743 unsigned NumDstElts =
1744 cast<llvm::VectorType>(Vec->getType())->getNumElements();
1745 if (NumDstElts == NumSrcElts) {
1746 // Use shuffle vector is the src and destination are the same number of
1747 // elements and restore the vector mask since it is on the side it will be
1749 SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1750 for (unsigned i = 0; i != NumSrcElts; ++i)
1751 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
1753 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1754 Vec = Builder.CreateShuffleVector(SrcVal,
1755 llvm::UndefValue::get(Vec->getType()),
1757 } else if (NumDstElts > NumSrcElts) {
1758 // Extended the source vector to the same length and then shuffle it
1759 // into the destination.
1760 // FIXME: since we're shuffling with undef, can we just use the indices
1761 // into that? This could be simpler.
1762 SmallVector<llvm::Constant*, 4> ExtMask;
1763 for (unsigned i = 0; i != NumSrcElts; ++i)
1764 ExtMask.push_back(Builder.getInt32(i));
1765 ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
1766 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
1767 llvm::Value *ExtSrcVal =
1768 Builder.CreateShuffleVector(SrcVal,
1769 llvm::UndefValue::get(SrcVal->getType()),
1772 SmallVector<llvm::Constant*, 4> Mask;
1773 for (unsigned i = 0; i != NumDstElts; ++i)
1774 Mask.push_back(Builder.getInt32(i));
1776 // When the vector size is odd and .odd or .hi is used, the last element
1777 // of the Elts constant array will be one past the size of the vector.
1778 // Ignore the last element here, if it is greater than the mask size.
1779 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
1782 // modify when what gets shuffled in
1783 for (unsigned i = 0; i != NumSrcElts; ++i)
1784 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
1785 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1786 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
1788 // We should never shorten the vector
1789 llvm_unreachable("unexpected shorten vector length");
1792 // If the Src is a scalar (not a vector) it must be updating one element.
1793 unsigned InIdx = getAccessedFieldNo(0, Elts);
1794 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1795 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
1798 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
1799 Dst.isVolatileQualified());
1802 /// @brief Store of global named registers are always calls to intrinsics.
1803 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
1804 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
1805 "Bad type for register variable");
1806 llvm::MDNode *RegName = cast<llvm::MDNode>(
1807 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
1808 assert(RegName && "Register LValue is not metadata");
1810 // We accept integer and pointer types only
1811 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
1812 llvm::Type *Ty = OrigTy;
1813 if (OrigTy->isPointerTy())
1814 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1815 llvm::Type *Types[] = { Ty };
1817 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
1818 llvm::Value *Value = Src.getScalarVal();
1819 if (OrigTy->isPointerTy())
1820 Value = Builder.CreatePtrToInt(Value, Ty);
1822 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
1825 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
1826 // generating write-barries API. It is currently a global, ivar,
1828 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1830 bool IsMemberAccess=false) {
1831 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
1834 if (isa<ObjCIvarRefExpr>(E)) {
1835 QualType ExpTy = E->getType();
1836 if (IsMemberAccess && ExpTy->isPointerType()) {
1837 // If ivar is a structure pointer, assigning to field of
1838 // this struct follows gcc's behavior and makes it a non-ivar
1839 // writer-barrier conservatively.
1840 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1841 if (ExpTy->isRecordType()) {
1842 LV.setObjCIvar(false);
1846 LV.setObjCIvar(true);
1847 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
1848 LV.setBaseIvarExp(Exp->getBase());
1849 LV.setObjCArray(E->getType()->isArrayType());
1853 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
1854 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1855 if (VD->hasGlobalStorage()) {
1856 LV.setGlobalObjCRef(true);
1857 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
1860 LV.setObjCArray(E->getType()->isArrayType());
1864 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
1865 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1869 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
1870 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1871 if (LV.isObjCIvar()) {
1872 // If cast is to a structure pointer, follow gcc's behavior and make it
1873 // a non-ivar write-barrier.
1874 QualType ExpTy = E->getType();
1875 if (ExpTy->isPointerType())
1876 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1877 if (ExpTy->isRecordType())
1878 LV.setObjCIvar(false);
1883 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
1884 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
1888 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1889 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1893 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
1894 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1898 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
1899 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1903 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1904 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1905 if (LV.isObjCIvar() && !LV.isObjCArray())
1906 // Using array syntax to assigning to what an ivar points to is not
1907 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1908 LV.setObjCIvar(false);
1909 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1910 // Using array syntax to assigning to what global points to is not
1911 // same as assigning to the global itself. {id *G;} G[i] = 0;
1912 LV.setGlobalObjCRef(false);
1916 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
1917 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
1918 // We don't know if member is an 'ivar', but this flag is looked at
1919 // only in the context of LV.isObjCIvar().
1920 LV.setObjCArray(E->getType()->isArrayType());
1925 static llvm::Value *
1926 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
1927 llvm::Value *V, llvm::Type *IRType,
1928 StringRef Name = StringRef()) {
1929 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
1930 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
1933 static LValue EmitThreadPrivateVarDeclLValue(
1934 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
1935 llvm::Type *RealVarTy, SourceLocation Loc) {
1936 Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
1937 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
1938 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
1941 Address CodeGenFunction::EmitLoadOfReference(Address Addr,
1942 const ReferenceType *RefTy,
1943 AlignmentSource *Source) {
1944 llvm::Value *Ptr = Builder.CreateLoad(Addr);
1945 return Address(Ptr, getNaturalTypeAlignment(RefTy->getPointeeType(),
1946 Source, /*forPointee*/ true));
1950 LValue CodeGenFunction::EmitLoadOfReferenceLValue(Address RefAddr,
1951 const ReferenceType *RefTy) {
1952 AlignmentSource Source;
1953 Address Addr = EmitLoadOfReference(RefAddr, RefTy, &Source);
1954 return MakeAddrLValue(Addr, RefTy->getPointeeType(), Source);
1957 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
1958 const PointerType *PtrTy,
1959 AlignmentSource *Source) {
1960 llvm::Value *Addr = Builder.CreateLoad(Ptr);
1961 return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(), Source,
1962 /*forPointeeType=*/true));
1965 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
1966 const PointerType *PtrTy) {
1967 AlignmentSource Source;
1968 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &Source);
1969 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), Source);
1972 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1973 const Expr *E, const VarDecl *VD) {
1974 QualType T = E->getType();
1976 // If it's thread_local, emit a call to its wrapper function instead.
1977 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
1978 CGF.CGM.getCXXABI().usesThreadWrapperFunction())
1979 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
1981 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1982 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
1983 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
1984 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
1985 Address Addr(V, Alignment);
1987 // Emit reference to the private copy of the variable if it is an OpenMP
1988 // threadprivate variable.
1989 if (CGF.getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>())
1990 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
1992 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
1993 LV = CGF.EmitLoadOfReferenceLValue(Addr, RefTy);
1995 LV = CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
1997 setObjCGCLValueClass(CGF.getContext(), E, LV);
2001 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
2002 const Expr *E, const FunctionDecl *FD) {
2003 llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD);
2004 if (!FD->hasPrototype()) {
2005 if (const FunctionProtoType *Proto =
2006 FD->getType()->getAs<FunctionProtoType>()) {
2007 // Ugly case: for a K&R-style definition, the type of the definition
2008 // isn't the same as the type of a use. Correct for this with a
2010 QualType NoProtoType =
2011 CGF.getContext().getFunctionNoProtoType(Proto->getReturnType());
2012 NoProtoType = CGF.getContext().getPointerType(NoProtoType);
2013 V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType));
2016 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2017 return CGF.MakeAddrLValue(V, E->getType(), Alignment, AlignmentSource::Decl);
2020 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2021 llvm::Value *ThisValue) {
2022 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2023 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2024 return CGF.EmitLValueForField(LV, FD);
2027 /// Named Registers are named metadata pointing to the register name
2028 /// which will be read from/written to as an argument to the intrinsic
2029 /// @llvm.read/write_register.
2030 /// So far, only the name is being passed down, but other options such as
2031 /// register type, allocation type or even optimization options could be
2032 /// passed down via the metadata node.
2033 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2034 SmallString<64> Name("llvm.named.register.");
2035 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2036 assert(Asm->getLabel().size() < 64-Name.size() &&
2037 "Register name too big");
2038 Name.append(Asm->getLabel());
2039 llvm::NamedMDNode *M =
2040 CGM.getModule().getOrInsertNamedMetadata(Name);
2041 if (M->getNumOperands() == 0) {
2042 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2044 llvm::Metadata *Ops[] = {Str};
2045 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2048 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2051 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2052 return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2055 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2056 const NamedDecl *ND = E->getDecl();
2057 QualType T = E->getType();
2059 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2060 // Global Named registers access via intrinsics only
2061 if (VD->getStorageClass() == SC_Register &&
2062 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2063 return EmitGlobalNamedRegister(VD, CGM);
2065 // A DeclRefExpr for a reference initialized by a constant expression can
2066 // appear without being odr-used. Directly emit the constant initializer.
2067 const Expr *Init = VD->getAnyInitializer(VD);
2068 if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2069 VD->isUsableInConstantExpressions(getContext()) &&
2070 VD->checkInitIsICE() &&
2071 // Do not emit if it is private OpenMP variable.
2072 !(E->refersToEnclosingVariableOrCapture() && CapturedStmtInfo &&
2073 LocalDeclMap.count(VD))) {
2074 llvm::Constant *Val =
2075 CGM.EmitConstantValue(*VD->evaluateValue(), VD->getType(), this);
2076 assert(Val && "failed to emit reference constant expression");
2077 // FIXME: Eventually we will want to emit vector element references.
2079 // Should we be using the alignment of the constant pointer we emitted?
2080 CharUnits Alignment = getNaturalTypeAlignment(E->getType(), nullptr,
2083 return MakeAddrLValue(Address(Val, Alignment), T, AlignmentSource::Decl);
2086 // Check for captured variables.
2087 if (E->refersToEnclosingVariableOrCapture()) {
2088 if (auto *FD = LambdaCaptureFields.lookup(VD))
2089 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2090 else if (CapturedStmtInfo) {
2091 auto it = LocalDeclMap.find(VD);
2092 if (it != LocalDeclMap.end()) {
2093 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2094 return EmitLoadOfReferenceLValue(it->second, RefTy);
2096 return MakeAddrLValue(it->second, T);
2099 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2100 CapturedStmtInfo->getContextValue());
2101 return MakeAddrLValue(
2102 Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2103 CapLVal.getType(), AlignmentSource::Decl);
2106 assert(isa<BlockDecl>(CurCodeDecl));
2107 Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
2108 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2112 // FIXME: We should be able to assert this for FunctionDecls as well!
2113 // FIXME: We should be able to assert this for all DeclRefExprs, not just
2114 // those with a valid source location.
2115 assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2116 !E->getLocation().isValid()) &&
2117 "Should not use decl without marking it used!");
2119 if (ND->hasAttr<WeakRefAttr>()) {
2120 const auto *VD = cast<ValueDecl>(ND);
2121 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2122 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2125 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2126 // Check if this is a global variable.
2127 if (VD->hasLinkage() || VD->isStaticDataMember())
2128 return EmitGlobalVarDeclLValue(*this, E, VD);
2130 Address addr = Address::invalid();
2132 // The variable should generally be present in the local decl map.
2133 auto iter = LocalDeclMap.find(VD);
2134 if (iter != LocalDeclMap.end()) {
2135 addr = iter->second;
2137 // Otherwise, it might be static local we haven't emitted yet for
2138 // some reason; most likely, because it's in an outer function.
2139 } else if (VD->isStaticLocal()) {
2140 addr = Address(CGM.getOrCreateStaticVarDecl(
2141 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2142 getContext().getDeclAlign(VD));
2144 // No other cases for now.
2146 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2150 // Check for OpenMP threadprivate variables.
2151 if (getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2152 return EmitThreadPrivateVarDeclLValue(
2153 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2157 // Drill into block byref variables.
2158 bool isBlockByref = VD->hasAttr<BlocksAttr>();
2160 addr = emitBlockByrefAddress(addr, VD);
2163 // Drill into reference types.
2165 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2166 LV = EmitLoadOfReferenceLValue(addr, RefTy);
2168 LV = MakeAddrLValue(addr, T, AlignmentSource::Decl);
2171 bool isLocalStorage = VD->hasLocalStorage();
2173 bool NonGCable = isLocalStorage &&
2174 !VD->getType()->isReferenceType() &&
2177 LV.getQuals().removeObjCGCAttr();
2181 bool isImpreciseLifetime =
2182 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2183 if (isImpreciseLifetime)
2184 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2185 setObjCGCLValueClass(getContext(), E, LV);
2189 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2190 return EmitFunctionDeclLValue(*this, E, FD);
2192 llvm_unreachable("Unhandled DeclRefExpr");
2195 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2196 // __extension__ doesn't affect lvalue-ness.
2197 if (E->getOpcode() == UO_Extension)
2198 return EmitLValue(E->getSubExpr());
2200 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2201 switch (E->getOpcode()) {
2202 default: llvm_unreachable("Unknown unary operator lvalue!");
2204 QualType T = E->getSubExpr()->getType()->getPointeeType();
2205 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2207 AlignmentSource AlignSource;
2208 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &AlignSource);
2209 LValue LV = MakeAddrLValue(Addr, T, AlignSource);
2210 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2212 // We should not generate __weak write barrier on indirect reference
2213 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2214 // But, we continue to generate __strong write barrier on indirect write
2215 // into a pointer to object.
2216 if (getLangOpts().ObjC1 &&
2217 getLangOpts().getGC() != LangOptions::NonGC &&
2219 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2224 LValue LV = EmitLValue(E->getSubExpr());
2225 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2227 // __real is valid on scalars. This is a faster way of testing that.
2228 // __imag can only produce an rvalue on scalars.
2229 if (E->getOpcode() == UO_Real &&
2230 !LV.getAddress().getElementType()->isStructTy()) {
2231 assert(E->getSubExpr()->getType()->isArithmeticType());
2235 assert(E->getSubExpr()->getType()->isAnyComplexType());
2238 (E->getOpcode() == UO_Real
2239 ? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
2240 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
2241 return MakeAddrLValue(Component, ExprTy, LV.getAlignmentSource());
2245 LValue LV = EmitLValue(E->getSubExpr());
2246 bool isInc = E->getOpcode() == UO_PreInc;
2248 if (E->getType()->isAnyComplexType())
2249 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2251 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2257 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2258 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2259 E->getType(), AlignmentSource::Decl);
2262 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2263 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2264 E->getType(), AlignmentSource::Decl);
2267 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2268 auto SL = E->getFunctionName();
2269 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2270 StringRef FnName = CurFn->getName();
2271 if (FnName.startswith("\01"))
2272 FnName = FnName.substr(1);
2273 StringRef NameItems[] = {
2274 PredefinedExpr::getIdentTypeName(E->getIdentType()), FnName};
2275 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2276 if (CurCodeDecl && isa<BlockDecl>(CurCodeDecl)) {
2277 auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2278 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2280 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2281 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2284 /// Emit a type description suitable for use by a runtime sanitizer library. The
2285 /// format of a type descriptor is
2288 /// { i16 TypeKind, i16 TypeInfo }
2291 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2292 /// integer, 1 for a floating point value, and -1 for anything else.
2293 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2294 // Only emit each type's descriptor once.
2295 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2298 uint16_t TypeKind = -1;
2299 uint16_t TypeInfo = 0;
2301 if (T->isIntegerType()) {
2303 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2304 (T->isSignedIntegerType() ? 1 : 0);
2305 } else if (T->isFloatingType()) {
2307 TypeInfo = getContext().getTypeSize(T);
2310 // Format the type name as if for a diagnostic, including quotes and
2311 // optionally an 'aka'.
2312 SmallString<32> Buffer;
2313 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
2314 (intptr_t)T.getAsOpaquePtr(),
2315 StringRef(), StringRef(), None, Buffer,
2318 llvm::Constant *Components[] = {
2319 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2320 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2322 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2324 auto *GV = new llvm::GlobalVariable(
2325 CGM.getModule(), Descriptor->getType(),
2326 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2327 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2328 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
2330 // Remember the descriptor for this type.
2331 CGM.setTypeDescriptorInMap(T, GV);
2336 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
2337 llvm::Type *TargetTy = IntPtrTy;
2339 // Floating-point types which fit into intptr_t are bitcast to integers
2340 // and then passed directly (after zero-extension, if necessary).
2341 if (V->getType()->isFloatingPointTy()) {
2342 unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2343 if (Bits <= TargetTy->getIntegerBitWidth())
2344 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2348 // Integers which fit in intptr_t are zero-extended and passed directly.
2349 if (V->getType()->isIntegerTy() &&
2350 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2351 return Builder.CreateZExt(V, TargetTy);
2353 // Pointers are passed directly, everything else is passed by address.
2354 if (!V->getType()->isPointerTy()) {
2355 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2356 Builder.CreateStore(V, Ptr);
2357 V = Ptr.getPointer();
2359 return Builder.CreatePtrToInt(V, TargetTy);
2362 /// \brief Emit a representation of a SourceLocation for passing to a handler
2363 /// in a sanitizer runtime library. The format for this data is:
2365 /// struct SourceLocation {
2366 /// const char *Filename;
2367 /// int32_t Line, Column;
2370 /// For an invalid SourceLocation, the Filename pointer is null.
2371 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
2372 llvm::Constant *Filename;
2375 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
2376 if (PLoc.isValid()) {
2377 StringRef FilenameString = PLoc.getFilename();
2379 int PathComponentsToStrip =
2380 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2381 if (PathComponentsToStrip < 0) {
2382 assert(PathComponentsToStrip != INT_MIN);
2383 int PathComponentsToKeep = -PathComponentsToStrip;
2384 auto I = llvm::sys::path::rbegin(FilenameString);
2385 auto E = llvm::sys::path::rend(FilenameString);
2386 while (I != E && --PathComponentsToKeep)
2389 FilenameString = FilenameString.substr(I - E);
2390 } else if (PathComponentsToStrip > 0) {
2391 auto I = llvm::sys::path::begin(FilenameString);
2392 auto E = llvm::sys::path::end(FilenameString);
2393 while (I != E && PathComponentsToStrip--)
2398 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2400 FilenameString = llvm::sys::path::filename(FilenameString);
2403 auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2404 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
2405 cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2406 Filename = FilenameGV.getPointer();
2407 Line = PLoc.getLine();
2408 Column = PLoc.getColumn();
2410 Filename = llvm::Constant::getNullValue(Int8PtrTy);
2414 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2415 Builder.getInt32(Column)};
2417 return llvm::ConstantStruct::getAnon(Data);
2421 /// \brief Specify under what conditions this check can be recovered
2422 enum class CheckRecoverableKind {
2423 /// Always terminate program execution if this check fails.
2425 /// Check supports recovering, runtime has both fatal (noreturn) and
2426 /// non-fatal handlers for this check.
2428 /// Runtime conditionally aborts, always need to support recovery.
2433 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
2434 assert(llvm::countPopulation(Kind) == 1);
2436 case SanitizerKind::Vptr:
2437 return CheckRecoverableKind::AlwaysRecoverable;
2438 case SanitizerKind::Return:
2439 case SanitizerKind::Unreachable:
2440 return CheckRecoverableKind::Unrecoverable;
2442 return CheckRecoverableKind::Recoverable;
2446 static void emitCheckHandlerCall(CodeGenFunction &CGF,
2447 llvm::FunctionType *FnType,
2448 ArrayRef<llvm::Value *> FnArgs,
2449 StringRef CheckName,
2450 CheckRecoverableKind RecoverKind, bool IsFatal,
2451 llvm::BasicBlock *ContBB) {
2452 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2453 bool NeedsAbortSuffix =
2454 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2455 std::string FnName = ("__ubsan_handle_" + CheckName +
2456 (NeedsAbortSuffix ? "_abort" : "")).str();
2458 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2460 llvm::AttrBuilder B;
2462 B.addAttribute(llvm::Attribute::NoReturn)
2463 .addAttribute(llvm::Attribute::NoUnwind);
2465 B.addAttribute(llvm::Attribute::UWTable);
2467 llvm::Value *Fn = CGF.CGM.CreateRuntimeFunction(
2469 llvm::AttributeSet::get(CGF.getLLVMContext(),
2470 llvm::AttributeSet::FunctionIndex, B));
2471 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2473 HandlerCall->setDoesNotReturn();
2474 CGF.Builder.CreateUnreachable();
2476 CGF.Builder.CreateBr(ContBB);
2480 void CodeGenFunction::EmitCheck(
2481 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2482 StringRef CheckName, ArrayRef<llvm::Constant *> StaticArgs,
2483 ArrayRef<llvm::Value *> DynamicArgs) {
2484 assert(IsSanitizerScope);
2485 assert(Checked.size() > 0);
2487 llvm::Value *FatalCond = nullptr;
2488 llvm::Value *RecoverableCond = nullptr;
2489 llvm::Value *TrapCond = nullptr;
2490 for (int i = 0, n = Checked.size(); i < n; ++i) {
2491 llvm::Value *Check = Checked[i].first;
2492 // -fsanitize-trap= overrides -fsanitize-recover=.
2493 llvm::Value *&Cond =
2494 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2496 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2499 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2503 EmitTrapCheck(TrapCond);
2504 if (!FatalCond && !RecoverableCond)
2507 llvm::Value *JointCond;
2508 if (FatalCond && RecoverableCond)
2509 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2511 JointCond = FatalCond ? FatalCond : RecoverableCond;
2514 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2515 assert(SanOpts.has(Checked[0].second));
2517 for (int i = 1, n = Checked.size(); i < n; ++i) {
2518 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2519 "All recoverable kinds in a single check must be same!");
2520 assert(SanOpts.has(Checked[i].second));
2524 llvm::BasicBlock *Cont = createBasicBlock("cont");
2525 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2526 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2527 // Give hint that we very much don't expect to execute the handler
2528 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2529 llvm::MDBuilder MDHelper(getLLVMContext());
2530 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2531 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2532 EmitBlock(Handlers);
2534 // Handler functions take an i8* pointing to the (handler-specific) static
2535 // information block, followed by a sequence of intptr_t arguments
2536 // representing operand values.
2537 SmallVector<llvm::Value *, 4> Args;
2538 SmallVector<llvm::Type *, 4> ArgTypes;
2539 Args.reserve(DynamicArgs.size() + 1);
2540 ArgTypes.reserve(DynamicArgs.size() + 1);
2542 // Emit handler arguments and create handler function type.
2543 if (!StaticArgs.empty()) {
2544 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2546 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2547 llvm::GlobalVariable::PrivateLinkage, Info);
2548 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2549 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2550 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
2551 ArgTypes.push_back(Int8PtrTy);
2554 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
2555 Args.push_back(EmitCheckValue(DynamicArgs[i]));
2556 ArgTypes.push_back(IntPtrTy);
2559 llvm::FunctionType *FnType =
2560 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
2562 if (!FatalCond || !RecoverableCond) {
2563 // Simple case: we need to generate a single handler call, either
2564 // fatal, or non-fatal.
2565 emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind,
2566 (FatalCond != nullptr), Cont);
2568 // Emit two handler calls: first one for set of unrecoverable checks,
2569 // another one for recoverable.
2570 llvm::BasicBlock *NonFatalHandlerBB =
2571 createBasicBlock("non_fatal." + CheckName);
2572 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
2573 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
2574 EmitBlock(FatalHandlerBB);
2575 emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind, true,
2577 EmitBlock(NonFatalHandlerBB);
2578 emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind, false,
2585 void CodeGenFunction::EmitCfiSlowPathCheck(
2586 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
2587 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
2588 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
2590 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
2591 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
2593 llvm::MDBuilder MDHelper(getLLVMContext());
2594 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2595 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
2599 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
2601 llvm::CallInst *CheckCall;
2603 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2605 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2606 llvm::GlobalVariable::PrivateLinkage, Info);
2607 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2608 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2610 llvm::Constant *SlowPathDiagFn = CGM.getModule().getOrInsertFunction(
2611 "__cfi_slowpath_diag",
2612 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
2614 CheckCall = Builder.CreateCall(
2616 {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
2618 llvm::Constant *SlowPathFn = CGM.getModule().getOrInsertFunction(
2620 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
2621 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
2624 CheckCall->setDoesNotThrow();
2629 // This function is basically a switch over the CFI failure kind, which is
2630 // extracted from CFICheckFailData (1st function argument). Each case is either
2631 // llvm.trap or a call to one of the two runtime handlers, based on
2632 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
2633 // failure kind) traps, but this should really never happen. CFICheckFailData
2634 // can be nullptr if the calling module has -fsanitize-trap behavior for this
2635 // check kind; in this case __cfi_check_fail traps as well.
2636 void CodeGenFunction::EmitCfiCheckFail() {
2637 SanitizerScope SanScope(this);
2638 FunctionArgList Args;
2639 ImplicitParamDecl ArgData(getContext(), nullptr, SourceLocation(), nullptr,
2640 getContext().VoidPtrTy);
2641 ImplicitParamDecl ArgAddr(getContext(), nullptr, SourceLocation(), nullptr,
2642 getContext().VoidPtrTy);
2643 Args.push_back(&ArgData);
2644 Args.push_back(&ArgAddr);
2646 const CGFunctionInfo &FI =
2647 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
2649 llvm::Function *F = llvm::Function::Create(
2650 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
2651 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
2652 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
2654 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
2658 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
2659 CGM.getContext().VoidPtrTy, ArgData.getLocation());
2661 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
2662 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
2664 // Data == nullptr means the calling module has trap behaviour for this check.
2665 llvm::Value *DataIsNotNullPtr =
2666 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
2667 EmitTrapCheck(DataIsNotNullPtr);
2669 llvm::StructType *SourceLocationTy =
2670 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty, nullptr);
2671 llvm::StructType *CfiCheckFailDataTy =
2672 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy, nullptr);
2674 llvm::Value *V = Builder.CreateConstGEP2_32(
2676 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
2678 Address CheckKindAddr(V, getIntAlign());
2679 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
2681 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
2682 CGM.getLLVMContext(),
2683 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
2684 llvm::Value *ValidVtable = Builder.CreateZExt(
2685 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
2686 {Addr, AllVtables}),
2689 const std::pair<int, SanitizerMask> CheckKinds[] = {
2690 {CFITCK_VCall, SanitizerKind::CFIVCall},
2691 {CFITCK_NVCall, SanitizerKind::CFINVCall},
2692 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
2693 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
2694 {CFITCK_ICall, SanitizerKind::CFIICall}};
2696 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
2697 for (auto CheckKindMaskPair : CheckKinds) {
2698 int Kind = CheckKindMaskPair.first;
2699 SanitizerMask Mask = CheckKindMaskPair.second;
2701 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
2702 if (CGM.getLangOpts().Sanitize.has(Mask))
2703 EmitCheck(std::make_pair(Cond, Mask), "cfi_check_fail", {},
2704 {Data, Addr, ValidVtable});
2706 EmitTrapCheck(Cond);
2710 // The only reference to this function will be created during LTO link.
2711 // Make sure it survives until then.
2712 CGM.addUsedGlobal(F);
2715 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
2716 llvm::BasicBlock *Cont = createBasicBlock("cont");
2718 // If we're optimizing, collapse all calls to trap down to just one per
2719 // function to save on code size.
2720 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
2721 TrapBB = createBasicBlock("trap");
2722 Builder.CreateCondBr(Checked, Cont, TrapBB);
2724 llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
2725 TrapCall->setDoesNotReturn();
2726 TrapCall->setDoesNotThrow();
2727 Builder.CreateUnreachable();
2729 Builder.CreateCondBr(Checked, Cont, TrapBB);
2735 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
2736 llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
2738 if (!CGM.getCodeGenOpts().TrapFuncName.empty())
2739 TrapCall->addAttribute(llvm::AttributeSet::FunctionIndex,
2741 CGM.getCodeGenOpts().TrapFuncName);
2746 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
2747 AlignmentSource *AlignSource) {
2748 assert(E->getType()->isArrayType() &&
2749 "Array to pointer decay must have array source type!");
2751 // Expressions of array type can't be bitfields or vector elements.
2752 LValue LV = EmitLValue(E);
2753 Address Addr = LV.getAddress();
2754 if (AlignSource) *AlignSource = LV.getAlignmentSource();
2756 // If the array type was an incomplete type, we need to make sure
2757 // the decay ends up being the right type.
2758 llvm::Type *NewTy = ConvertType(E->getType());
2759 Addr = Builder.CreateElementBitCast(Addr, NewTy);
2761 // Note that VLA pointers are always decayed, so we don't need to do
2763 if (!E->getType()->isVariableArrayType()) {
2764 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
2765 "Expected pointer to array");
2766 Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
2769 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
2770 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
2773 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
2774 /// array to pointer, return the array subexpression.
2775 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
2776 // If this isn't just an array->pointer decay, bail out.
2777 const auto *CE = dyn_cast<CastExpr>(E);
2778 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
2781 // If this is a decay from variable width array, bail out.
2782 const Expr *SubExpr = CE->getSubExpr();
2783 if (SubExpr->getType()->isVariableArrayType())
2789 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
2791 ArrayRef<llvm::Value*> indices,
2793 const llvm::Twine &name = "arrayidx") {
2795 return CGF.Builder.CreateInBoundsGEP(ptr, indices, name);
2797 return CGF.Builder.CreateGEP(ptr, indices, name);
2801 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
2803 CharUnits eltSize) {
2804 // If we have a constant index, we can use the exact offset of the
2805 // element we're accessing.
2806 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
2807 CharUnits offset = constantIdx->getZExtValue() * eltSize;
2808 return arrayAlign.alignmentAtOffset(offset);
2810 // Otherwise, use the worst-case alignment for any element.
2812 return arrayAlign.alignmentOfArrayElement(eltSize);
2816 static QualType getFixedSizeElementType(const ASTContext &ctx,
2817 const VariableArrayType *vla) {
2820 eltType = vla->getElementType();
2821 } while ((vla = ctx.getAsVariableArrayType(eltType)));
2825 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
2826 ArrayRef<llvm::Value*> indices,
2827 QualType eltType, bool inbounds,
2828 const llvm::Twine &name = "arrayidx") {
2829 // All the indices except that last must be zero.
2831 for (auto idx : indices.drop_back())
2832 assert(isa<llvm::ConstantInt>(idx) &&
2833 cast<llvm::ConstantInt>(idx)->isZero());
2836 // Determine the element size of the statically-sized base. This is
2837 // the thing that the indices are expressed in terms of.
2838 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
2839 eltType = getFixedSizeElementType(CGF.getContext(), vla);
2842 // We can use that to compute the best alignment of the element.
2843 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
2844 CharUnits eltAlign =
2845 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
2847 llvm::Value *eltPtr =
2848 emitArraySubscriptGEP(CGF, addr.getPointer(), indices, inbounds, name);
2849 return Address(eltPtr, eltAlign);
2852 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
2854 // The index must always be an integer, which is not an aggregate. Emit it.
2855 llvm::Value *Idx = EmitScalarExpr(E->getIdx());
2856 QualType IdxTy = E->getIdx()->getType();
2857 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
2859 if (SanOpts.has(SanitizerKind::ArrayBounds))
2860 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
2862 // If the base is a vector type, then we are forming a vector element lvalue
2863 // with this subscript.
2864 if (E->getBase()->getType()->isVectorType() &&
2865 !isa<ExtVectorElementExpr>(E->getBase())) {
2866 // Emit the vector as an lvalue to get its address.
2867 LValue LHS = EmitLValue(E->getBase());
2868 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
2869 return LValue::MakeVectorElt(LHS.getAddress(), Idx,
2870 E->getBase()->getType(),
2871 LHS.getAlignmentSource());
2874 // All the other cases basically behave like simple offsetting.
2876 // Extend or truncate the index type to 32 or 64-bits.
2877 if (Idx->getType() != IntPtrTy)
2878 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
2880 // Handle the extvector case we ignored above.
2881 if (isa<ExtVectorElementExpr>(E->getBase())) {
2882 LValue LV = EmitLValue(E->getBase());
2883 Address Addr = EmitExtVectorElementLValue(LV);
2885 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
2886 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true);
2887 return MakeAddrLValue(Addr, EltType, LV.getAlignmentSource());
2890 AlignmentSource AlignSource;
2891 Address Addr = Address::invalid();
2892 if (const VariableArrayType *vla =
2893 getContext().getAsVariableArrayType(E->getType())) {
2894 // The base must be a pointer, which is not an aggregate. Emit
2895 // it. It needs to be emitted first in case it's what captures
2897 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
2899 // The element count here is the total number of non-VLA elements.
2900 llvm::Value *numElements = getVLASize(vla).first;
2902 // Effectively, the multiply by the VLA size is part of the GEP.
2903 // GEP indexes are signed, and scaling an index isn't permitted to
2904 // signed-overflow, so we use the same semantics for our explicit
2905 // multiply. We suppress this if overflow is not undefined behavior.
2906 if (getLangOpts().isSignedOverflowDefined()) {
2907 Idx = Builder.CreateMul(Idx, numElements);
2909 Idx = Builder.CreateNSWMul(Idx, numElements);
2912 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
2913 !getLangOpts().isSignedOverflowDefined());
2915 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
2916 // Indexing over an interface, as in "NSString *P; P[4];"
2917 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
2918 llvm::Value *InterfaceSizeVal =
2919 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());;
2921 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
2923 // Emit the base pointer.
2924 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
2926 // We don't necessarily build correct LLVM struct types for ObjC
2927 // interfaces, so we can't rely on GEP to do this scaling
2928 // correctly, so we need to cast to i8*. FIXME: is this actually
2929 // true? A lot of other things in the fragile ABI would break...
2930 llvm::Type *OrigBaseTy = Addr.getType();
2931 Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
2934 CharUnits EltAlign =
2935 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
2936 llvm::Value *EltPtr =
2937 emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false);
2938 Addr = Address(EltPtr, EltAlign);
2941 Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
2942 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
2943 // If this is A[i] where A is an array, the frontend will have decayed the
2944 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
2945 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
2946 // "gep x, i" here. Emit one "gep A, 0, i".
2947 assert(Array->getType()->isArrayType() &&
2948 "Array to pointer decay must have array source type!");
2950 // For simple multidimensional array indexing, set the 'accessed' flag for
2951 // better bounds-checking of the base expression.
2952 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
2953 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
2955 ArrayLV = EmitLValue(Array);
2957 // Propagate the alignment from the array itself to the result.
2958 Addr = emitArraySubscriptGEP(*this, ArrayLV.getAddress(),
2959 {CGM.getSize(CharUnits::Zero()), Idx},
2961 !getLangOpts().isSignedOverflowDefined());
2962 AlignSource = ArrayLV.getAlignmentSource();
2964 // The base must be a pointer; emit it with an estimate of its alignment.
2965 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
2966 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
2967 !getLangOpts().isSignedOverflowDefined());
2970 LValue LV = MakeAddrLValue(Addr, E->getType(), AlignSource);
2972 // TODO: Preserve/extend path TBAA metadata?
2974 if (getLangOpts().ObjC1 &&
2975 getLangOpts().getGC() != LangOptions::NonGC) {
2976 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2977 setObjCGCLValueClass(getContext(), E, LV);
2982 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
2983 AlignmentSource &AlignSource,
2984 QualType BaseTy, QualType ElTy,
2985 bool IsLowerBound) {
2987 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
2988 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
2989 if (BaseTy->isArrayType()) {
2990 Address Addr = BaseLVal.getAddress();
2991 AlignSource = BaseLVal.getAlignmentSource();
2993 // If the array type was an incomplete type, we need to make sure
2994 // the decay ends up being the right type.
2995 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
2996 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
2998 // Note that VLA pointers are always decayed, so we don't need to do
3000 if (!BaseTy->isVariableArrayType()) {
3001 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3002 "Expected pointer to array");
3003 Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
3007 return CGF.Builder.CreateElementBitCast(Addr,
3008 CGF.ConvertTypeForMem(ElTy));
3010 CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &AlignSource);
3011 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3013 return CGF.EmitPointerWithAlignment(Base, &AlignSource);
3016 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3017 bool IsLowerBound) {
3020 dyn_cast<OMPArraySectionExpr>(E->getBase()->IgnoreParenImpCasts()))
3021 BaseTy = OMPArraySectionExpr::getBaseOriginalType(ASE);
3023 BaseTy = E->getBase()->getType();
3024 QualType ResultExprTy;
3025 if (auto *AT = getContext().getAsArrayType(BaseTy))
3026 ResultExprTy = AT->getElementType();
3028 ResultExprTy = BaseTy->getPointeeType();
3029 llvm::Value *Idx = nullptr;
3030 if (IsLowerBound || E->getColonLoc().isInvalid()) {
3031 // Requesting lower bound or upper bound, but without provided length and
3032 // without ':' symbol for the default length -> length = 1.
3033 // Idx = LowerBound ?: 0;
3034 if (auto *LowerBound = E->getLowerBound()) {
3035 Idx = Builder.CreateIntCast(
3036 EmitScalarExpr(LowerBound), IntPtrTy,
3037 LowerBound->getType()->hasSignedIntegerRepresentation());
3039 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3041 // Try to emit length or lower bound as constant. If this is possible, 1
3042 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3043 // IR (LB + Len) - 1.
3044 auto &C = CGM.getContext();
3045 auto *Length = E->getLength();
3046 llvm::APSInt ConstLength;
3048 // Idx = LowerBound + Length - 1;
3049 if (Length->isIntegerConstantExpr(ConstLength, C)) {
3050 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3053 auto *LowerBound = E->getLowerBound();
3054 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3055 if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3056 ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3057 LowerBound = nullptr;
3061 else if (!LowerBound)
3064 if (Length || LowerBound) {
3065 auto *LowerBoundVal =
3067 ? Builder.CreateIntCast(
3068 EmitScalarExpr(LowerBound), IntPtrTy,
3069 LowerBound->getType()->hasSignedIntegerRepresentation())
3070 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3073 ? Builder.CreateIntCast(
3074 EmitScalarExpr(Length), IntPtrTy,
3075 Length->getType()->hasSignedIntegerRepresentation())
3076 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3077 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3079 !getLangOpts().isSignedOverflowDefined());
3080 if (Length && LowerBound) {
3081 Idx = Builder.CreateSub(
3082 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3083 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3086 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3088 // Idx = ArraySize - 1;
3089 QualType ArrayTy = BaseTy->isPointerType()
3090 ? E->getBase()->IgnoreParenImpCasts()->getType()
3092 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3093 Length = VAT->getSizeExpr();
3094 if (Length->isIntegerConstantExpr(ConstLength, C))
3097 auto *CAT = C.getAsConstantArrayType(ArrayTy);
3098 ConstLength = CAT->getSize();
3101 auto *LengthVal = Builder.CreateIntCast(
3102 EmitScalarExpr(Length), IntPtrTy,
3103 Length->getType()->hasSignedIntegerRepresentation());
3104 Idx = Builder.CreateSub(
3105 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3106 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3108 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3110 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3116 Address EltPtr = Address::invalid();
3117 AlignmentSource AlignSource;
3118 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3119 // The base must be a pointer, which is not an aggregate. Emit
3120 // it. It needs to be emitted first in case it's what captures
3123 emitOMPArraySectionBase(*this, E->getBase(), AlignSource, BaseTy,
3124 VLA->getElementType(), IsLowerBound);
3125 // The element count here is the total number of non-VLA elements.
3126 llvm::Value *NumElements = getVLASize(VLA).first;
3128 // Effectively, the multiply by the VLA size is part of the GEP.
3129 // GEP indexes are signed, and scaling an index isn't permitted to
3130 // signed-overflow, so we use the same semantics for our explicit
3131 // multiply. We suppress this if overflow is not undefined behavior.
3132 if (getLangOpts().isSignedOverflowDefined())
3133 Idx = Builder.CreateMul(Idx, NumElements);
3135 Idx = Builder.CreateNSWMul(Idx, NumElements);
3136 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3137 !getLangOpts().isSignedOverflowDefined());
3138 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3139 // If this is A[i] where A is an array, the frontend will have decayed the
3140 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3141 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3142 // "gep x, i" here. Emit one "gep A, 0, i".
3143 assert(Array->getType()->isArrayType() &&
3144 "Array to pointer decay must have array source type!");
3146 // For simple multidimensional array indexing, set the 'accessed' flag for
3147 // better bounds-checking of the base expression.
3148 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3149 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3151 ArrayLV = EmitLValue(Array);
3153 // Propagate the alignment from the array itself to the result.
3154 EltPtr = emitArraySubscriptGEP(
3155 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3156 ResultExprTy, !getLangOpts().isSignedOverflowDefined());
3157 AlignSource = ArrayLV.getAlignmentSource();
3159 Address Base = emitOMPArraySectionBase(*this, E->getBase(), AlignSource,
3160 BaseTy, ResultExprTy, IsLowerBound);
3161 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3162 !getLangOpts().isSignedOverflowDefined());
3165 return MakeAddrLValue(EltPtr, ResultExprTy, AlignSource);
3168 LValue CodeGenFunction::
3169 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
3170 // Emit the base vector as an l-value.
3173 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3175 // If it is a pointer to a vector, emit the address and form an lvalue with
3177 AlignmentSource AlignSource;
3178 Address Ptr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
3179 const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3180 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), AlignSource);
3181 Base.getQuals().removeObjCGCAttr();
3182 } else if (E->getBase()->isGLValue()) {
3183 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3184 // emit the base as an lvalue.
3185 assert(E->getBase()->getType()->isVectorType());
3186 Base = EmitLValue(E->getBase());
3188 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3189 assert(E->getBase()->getType()->isVectorType() &&
3190 "Result must be a vector");
3191 llvm::Value *Vec = EmitScalarExpr(E->getBase());
3193 // Store the vector to memory (because LValue wants an address).
3194 Address VecMem = CreateMemTemp(E->getBase()->getType());
3195 Builder.CreateStore(Vec, VecMem);
3196 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3197 AlignmentSource::Decl);
3201 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
3203 // Encode the element access list into a vector of unsigned indices.
3204 SmallVector<uint32_t, 4> Indices;
3205 E->getEncodedElementAccess(Indices);
3207 if (Base.isSimple()) {
3208 llvm::Constant *CV =
3209 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3210 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3211 Base.getAlignmentSource());
3213 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3215 llvm::Constant *BaseElts = Base.getExtVectorElts();
3216 SmallVector<llvm::Constant *, 4> CElts;
3218 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3219 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3220 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3221 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
3222 Base.getAlignmentSource());
3225 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
3226 Expr *BaseExpr = E->getBase();
3228 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3231 AlignmentSource AlignSource;
3232 Address Addr = EmitPointerWithAlignment(BaseExpr, &AlignSource);
3233 QualType PtrTy = BaseExpr->getType()->getPointeeType();
3234 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy);
3235 BaseLV = MakeAddrLValue(Addr, PtrTy, AlignSource);
3237 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3239 NamedDecl *ND = E->getMemberDecl();
3240 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3241 LValue LV = EmitLValueForField(BaseLV, Field);
3242 setObjCGCLValueClass(getContext(), E, LV);
3246 if (auto *VD = dyn_cast<VarDecl>(ND))
3247 return EmitGlobalVarDeclLValue(*this, E, VD);
3249 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3250 return EmitFunctionDeclLValue(*this, E, FD);
3252 llvm_unreachable("Unhandled member declaration!");
3255 /// Given that we are currently emitting a lambda, emit an l-value for
3256 /// one of its members.
3257 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
3258 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3259 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3260 QualType LambdaTagType =
3261 getContext().getTagDeclType(Field->getParent());
3262 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3263 return EmitLValueForField(LambdaLV, Field);
3266 /// Drill down to the storage of a field without walking into
3267 /// reference types.
3269 /// The resulting address doesn't necessarily have the right type.
3270 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
3271 const FieldDecl *field) {
3272 const RecordDecl *rec = field->getParent();
3275 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3278 // Adjust the alignment down to the given offset.
3279 // As a special case, if the LLVM field index is 0, we know that this
3281 assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
3282 .getFieldOffset(field->getFieldIndex()) == 0) &&
3283 "LLVM field at index zero had non-zero offset?");
3285 auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
3286 auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
3287 offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
3290 return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
3293 LValue CodeGenFunction::EmitLValueForField(LValue base,
3294 const FieldDecl *field) {
3295 AlignmentSource fieldAlignSource =
3296 getFieldAlignmentSource(base.getAlignmentSource());
3298 if (field->isBitField()) {
3299 const CGRecordLayout &RL =
3300 CGM.getTypes().getCGRecordLayout(field->getParent());
3301 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3302 Address Addr = base.getAddress();
3303 unsigned Idx = RL.getLLVMFieldNo(field);
3305 // For structs, we GEP to the field that the record layout suggests.
3306 Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
3308 // Get the access type.
3309 llvm::Type *FieldIntTy =
3310 llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3311 if (Addr.getElementType() != FieldIntTy)
3312 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3314 QualType fieldType =
3315 field->getType().withCVRQualifiers(base.getVRQualifiers());
3316 return LValue::MakeBitfield(Addr, Info, fieldType, fieldAlignSource);
3319 const RecordDecl *rec = field->getParent();
3320 QualType type = field->getType();
3322 bool mayAlias = rec->hasAttr<MayAliasAttr>();
3324 Address addr = base.getAddress();
3325 unsigned cvr = base.getVRQualifiers();
3326 bool TBAAPath = CGM.getCodeGenOpts().StructPathTBAA;
3327 if (rec->isUnion()) {
3328 // For unions, there is no pointer adjustment.
3329 assert(!type->isReferenceType() && "union has reference member");
3330 // TODO: handle path-aware TBAA for union.
3333 // For structs, we GEP to the field that the record layout suggests.
3334 addr = emitAddrOfFieldStorage(*this, addr, field);
3336 // If this is a reference field, load the reference right now.
3337 if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
3338 llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
3339 if (cvr & Qualifiers::Volatile) load->setVolatile(true);
3341 // Loading the reference will disable path-aware TBAA.
3343 if (CGM.shouldUseTBAA()) {
3346 tbaa = CGM.getTBAAInfo(getContext().CharTy);
3348 tbaa = CGM.getTBAAInfo(type);
3350 CGM.DecorateInstructionWithTBAA(load, tbaa);
3354 type = refType->getPointeeType();
3356 CharUnits alignment =
3357 getNaturalTypeAlignment(type, &fieldAlignSource, /*pointee*/ true);
3358 addr = Address(load, alignment);
3360 // Qualifiers on the struct don't apply to the referencee, and
3361 // we'll pick up CVR from the actual type later, so reset these
3362 // additional qualifiers now.
3367 // Make sure that the address is pointing to the right type. This is critical
3368 // for both unions and structs. A union needs a bitcast, a struct element
3369 // will need a bitcast if the LLVM type laid out doesn't match the desired
3371 addr = Builder.CreateElementBitCast(addr,
3372 CGM.getTypes().ConvertTypeForMem(type),
3375 if (field->hasAttr<AnnotateAttr>())
3376 addr = EmitFieldAnnotations(field, addr);
3378 LValue LV = MakeAddrLValue(addr, type, fieldAlignSource);
3379 LV.getQuals().addCVRQualifiers(cvr);
3381 const ASTRecordLayout &Layout =
3382 getContext().getASTRecordLayout(field->getParent());
3383 // Set the base type to be the base type of the base LValue and
3384 // update offset to be relative to the base type.
3385 LV.setTBAABaseType(mayAlias ? getContext().CharTy : base.getTBAABaseType());
3386 LV.setTBAAOffset(mayAlias ? 0 : base.getTBAAOffset() +
3387 Layout.getFieldOffset(field->getFieldIndex()) /
3388 getContext().getCharWidth());
3391 // __weak attribute on a field is ignored.
3392 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3393 LV.getQuals().removeObjCGCAttr();
3395 // Fields of may_alias structs act like 'char' for TBAA purposes.
3396 // FIXME: this should get propagated down through anonymous structs
3398 if (mayAlias && LV.getTBAAInfo())
3399 LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
3405 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
3406 const FieldDecl *Field) {
3407 QualType FieldType = Field->getType();
3409 if (!FieldType->isReferenceType())
3410 return EmitLValueForField(Base, Field);
3412 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3414 // Make sure that the address is pointing to the right type.
3415 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3416 V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3418 // TODO: access-path TBAA?
3419 auto FieldAlignSource = getFieldAlignmentSource(Base.getAlignmentSource());
3420 return MakeAddrLValue(V, FieldType, FieldAlignSource);
3423 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
3424 if (E->isFileScope()) {
3425 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
3426 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
3428 if (E->getType()->isVariablyModifiedType())
3429 // make sure to emit the VLA size.
3430 EmitVariablyModifiedType(E->getType());
3432 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
3433 const Expr *InitExpr = E->getInitializer();
3434 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
3436 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
3442 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
3443 if (!E->isGLValue())
3444 // Initializing an aggregate temporary in C++11: T{...}.
3445 return EmitAggExprToLValue(E);
3447 // An lvalue initializer list must be initializing a reference.
3448 assert(E->getNumInits() == 1 && "reference init with multiple values");
3449 return EmitLValue(E->getInit(0));
3452 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
3453 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
3454 /// LValue is returned and the current block has been terminated.
3455 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
3456 const Expr *Operand) {
3457 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
3458 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
3462 return CGF.EmitLValue(Operand);
3465 LValue CodeGenFunction::
3466 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
3467 if (!expr->isGLValue()) {
3468 // ?: here should be an aggregate.
3469 assert(hasAggregateEvaluationKind(expr->getType()) &&
3470 "Unexpected conditional operator!");
3471 return EmitAggExprToLValue(expr);
3474 OpaqueValueMapping binding(*this, expr);
3476 const Expr *condExpr = expr->getCond();
3478 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
3479 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
3480 if (!CondExprBool) std::swap(live, dead);
3482 if (!ContainsLabel(dead)) {
3483 // If the true case is live, we need to track its region.
3485 incrementProfileCounter(expr);
3486 return EmitLValue(live);
3490 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
3491 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
3492 llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
3494 ConditionalEvaluation eval(*this);
3495 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
3497 // Any temporaries created here are conditional.
3498 EmitBlock(lhsBlock);
3499 incrementProfileCounter(expr);
3501 Optional<LValue> lhs =
3502 EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
3505 if (lhs && !lhs->isSimple())
3506 return EmitUnsupportedLValue(expr, "conditional operator");
3508 lhsBlock = Builder.GetInsertBlock();
3510 Builder.CreateBr(contBlock);
3512 // Any temporaries created here are conditional.
3513 EmitBlock(rhsBlock);
3515 Optional<LValue> rhs =
3516 EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
3518 if (rhs && !rhs->isSimple())
3519 return EmitUnsupportedLValue(expr, "conditional operator");
3520 rhsBlock = Builder.GetInsertBlock();
3522 EmitBlock(contBlock);
3525 llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
3527 phi->addIncoming(lhs->getPointer(), lhsBlock);
3528 phi->addIncoming(rhs->getPointer(), rhsBlock);
3529 Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
3530 AlignmentSource alignSource =
3531 std::max(lhs->getAlignmentSource(), rhs->getAlignmentSource());
3532 return MakeAddrLValue(result, expr->getType(), alignSource);
3534 assert((lhs || rhs) &&
3535 "both operands of glvalue conditional are throw-expressions?");
3536 return lhs ? *lhs : *rhs;
3540 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
3541 /// type. If the cast is to a reference, we can have the usual lvalue result,
3542 /// otherwise if a cast is needed by the code generator in an lvalue context,
3543 /// then it must mean that we need the address of an aggregate in order to
3544 /// access one of its members. This can happen for all the reasons that casts
3545 /// are permitted with aggregate result, including noop aggregate casts, and
3546 /// cast from scalar to union.
3547 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
3548 switch (E->getCastKind()) {
3551 case CK_ArrayToPointerDecay:
3552 case CK_FunctionToPointerDecay:
3553 case CK_NullToMemberPointer:
3554 case CK_NullToPointer:
3555 case CK_IntegralToPointer:
3556 case CK_PointerToIntegral:
3557 case CK_PointerToBoolean:
3558 case CK_VectorSplat:
3559 case CK_IntegralCast:
3560 case CK_BooleanToSignedIntegral:
3561 case CK_IntegralToBoolean:
3562 case CK_IntegralToFloating:
3563 case CK_FloatingToIntegral:
3564 case CK_FloatingToBoolean:
3565 case CK_FloatingCast:
3566 case CK_FloatingRealToComplex:
3567 case CK_FloatingComplexToReal:
3568 case CK_FloatingComplexToBoolean:
3569 case CK_FloatingComplexCast:
3570 case CK_FloatingComplexToIntegralComplex:
3571 case CK_IntegralRealToComplex:
3572 case CK_IntegralComplexToReal:
3573 case CK_IntegralComplexToBoolean:
3574 case CK_IntegralComplexCast:
3575 case CK_IntegralComplexToFloatingComplex:
3576 case CK_DerivedToBaseMemberPointer:
3577 case CK_BaseToDerivedMemberPointer:
3578 case CK_MemberPointerToBoolean:
3579 case CK_ReinterpretMemberPointer:
3580 case CK_AnyPointerToBlockPointerCast:
3581 case CK_ARCProduceObject:
3582 case CK_ARCConsumeObject:
3583 case CK_ARCReclaimReturnedObject:
3584 case CK_ARCExtendBlockObject:
3585 case CK_CopyAndAutoreleaseBlockObject:
3586 case CK_AddressSpaceConversion:
3587 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
3590 llvm_unreachable("dependent cast kind in IR gen!");
3592 case CK_BuiltinFnToFnPtr:
3593 llvm_unreachable("builtin functions are handled elsewhere");
3595 // These are never l-values; just use the aggregate emission code.
3596 case CK_NonAtomicToAtomic:
3597 case CK_AtomicToNonAtomic:
3598 return EmitAggExprToLValue(E);
3601 LValue LV = EmitLValue(E->getSubExpr());
3602 Address V = LV.getAddress();
3603 const auto *DCE = cast<CXXDynamicCastExpr>(E);
3604 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
3607 case CK_ConstructorConversion:
3608 case CK_UserDefinedConversion:
3609 case CK_CPointerToObjCPointerCast:
3610 case CK_BlockPointerToObjCPointerCast:
3612 case CK_LValueToRValue:
3613 return EmitLValue(E->getSubExpr());
3615 case CK_UncheckedDerivedToBase:
3616 case CK_DerivedToBase: {
3617 const RecordType *DerivedClassTy =
3618 E->getSubExpr()->getType()->getAs<RecordType>();
3619 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3621 LValue LV = EmitLValue(E->getSubExpr());
3622 Address This = LV.getAddress();
3624 // Perform the derived-to-base conversion
3625 Address Base = GetAddressOfBaseClass(
3626 This, DerivedClassDecl, E->path_begin(), E->path_end(),
3627 /*NullCheckValue=*/false, E->getExprLoc());
3629 return MakeAddrLValue(Base, E->getType(), LV.getAlignmentSource());
3632 return EmitAggExprToLValue(E);
3633 case CK_BaseToDerived: {
3634 const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
3635 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3637 LValue LV = EmitLValue(E->getSubExpr());
3639 // Perform the base-to-derived conversion
3641 GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
3642 E->path_begin(), E->path_end(),
3643 /*NullCheckValue=*/false);
3645 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
3646 // performed and the object is not of the derived type.
3647 if (sanitizePerformTypeCheck())
3648 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
3649 Derived.getPointer(), E->getType());
3651 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
3652 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
3653 /*MayBeNull=*/false,
3654 CFITCK_DerivedCast, E->getLocStart());
3656 return MakeAddrLValue(Derived, E->getType(), LV.getAlignmentSource());
3658 case CK_LValueBitCast: {
3659 // This must be a reinterpret_cast (or c-style equivalent).
3660 const auto *CE = cast<ExplicitCastExpr>(E);
3662 CGM.EmitExplicitCastExprType(CE, this);
3663 LValue LV = EmitLValue(E->getSubExpr());
3664 Address V = Builder.CreateBitCast(LV.getAddress(),
3665 ConvertType(CE->getTypeAsWritten()));
3667 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
3668 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
3669 /*MayBeNull=*/false,
3670 CFITCK_UnrelatedCast, E->getLocStart());
3672 return MakeAddrLValue(V, E->getType(), LV.getAlignmentSource());
3674 case CK_ObjCObjectLValueCast: {
3675 LValue LV = EmitLValue(E->getSubExpr());
3676 Address V = Builder.CreateElementBitCast(LV.getAddress(),
3677 ConvertType(E->getType()));
3678 return MakeAddrLValue(V, E->getType(), LV.getAlignmentSource());
3680 case CK_ZeroToOCLEvent:
3681 llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
3684 llvm_unreachable("Unhandled lvalue cast kind?");
3687 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
3688 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
3689 return getOpaqueLValueMapping(e);
3692 RValue CodeGenFunction::EmitRValueForField(LValue LV,
3693 const FieldDecl *FD,
3694 SourceLocation Loc) {
3695 QualType FT = FD->getType();
3696 LValue FieldLV = EmitLValueForField(LV, FD);
3697 switch (getEvaluationKind(FT)) {
3699 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
3701 return FieldLV.asAggregateRValue();
3703 // This routine is used to load fields one-by-one to perform a copy, so
3704 // don't load reference fields.
3705 if (FD->getType()->isReferenceType())
3706 return RValue::get(FieldLV.getPointer());
3707 return EmitLoadOfLValue(FieldLV, Loc);
3709 llvm_unreachable("bad evaluation kind");
3712 //===--------------------------------------------------------------------===//
3713 // Expression Emission
3714 //===--------------------------------------------------------------------===//
3716 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
3717 ReturnValueSlot ReturnValue) {
3718 // Builtins never have block type.
3719 if (E->getCallee()->getType()->isBlockPointerType())
3720 return EmitBlockCallExpr(E, ReturnValue);
3722 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
3723 return EmitCXXMemberCallExpr(CE, ReturnValue);
3725 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
3726 return EmitCUDAKernelCallExpr(CE, ReturnValue);
3728 const Decl *TargetDecl = E->getCalleeDecl();
3729 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl)) {
3730 if (unsigned builtinID = FD->getBuiltinID())
3731 return EmitBuiltinExpr(FD, builtinID, E, ReturnValue);
3734 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
3735 if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
3736 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
3738 if (const auto *PseudoDtor =
3739 dyn_cast<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
3740 QualType DestroyedType = PseudoDtor->getDestroyedType();
3741 if (DestroyedType.hasStrongOrWeakObjCLifetime()) {
3742 // Automatic Reference Counting:
3743 // If the pseudo-expression names a retainable object with weak or
3744 // strong lifetime, the object shall be released.
3745 Expr *BaseExpr = PseudoDtor->getBase();
3746 Address BaseValue = Address::invalid();
3747 Qualifiers BaseQuals;
3749 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3750 if (PseudoDtor->isArrow()) {
3751 BaseValue = EmitPointerWithAlignment(BaseExpr);
3752 const PointerType *PTy = BaseExpr->getType()->getAs<PointerType>();
3753 BaseQuals = PTy->getPointeeType().getQualifiers();
3755 LValue BaseLV = EmitLValue(BaseExpr);
3756 BaseValue = BaseLV.getAddress();
3757 QualType BaseTy = BaseExpr->getType();
3758 BaseQuals = BaseTy.getQualifiers();
3761 switch (DestroyedType.getObjCLifetime()) {
3762 case Qualifiers::OCL_None:
3763 case Qualifiers::OCL_ExplicitNone:
3764 case Qualifiers::OCL_Autoreleasing:
3767 case Qualifiers::OCL_Strong:
3768 EmitARCRelease(Builder.CreateLoad(BaseValue,
3769 PseudoDtor->getDestroyedType().isVolatileQualified()),
3770 ARCPreciseLifetime);
3773 case Qualifiers::OCL_Weak:
3774 EmitARCDestroyWeak(BaseValue);
3778 // C++ [expr.pseudo]p1:
3779 // The result shall only be used as the operand for the function call
3780 // operator (), and the result of such a call has type void. The only
3781 // effect is the evaluation of the postfix-expression before the dot or
3783 EmitScalarExpr(E->getCallee());
3786 return RValue::get(nullptr);
3789 llvm::Value *Callee = EmitScalarExpr(E->getCallee());
3790 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue,
3794 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
3795 // Comma expressions just emit their LHS then their RHS as an l-value.
3796 if (E->getOpcode() == BO_Comma) {
3797 EmitIgnoredExpr(E->getLHS());
3798 EnsureInsertPoint();
3799 return EmitLValue(E->getRHS());
3802 if (E->getOpcode() == BO_PtrMemD ||
3803 E->getOpcode() == BO_PtrMemI)
3804 return EmitPointerToDataMemberBinaryExpr(E);
3806 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
3808 // Note that in all of these cases, __block variables need the RHS
3809 // evaluated first just in case the variable gets moved by the RHS.
3811 switch (getEvaluationKind(E->getType())) {
3813 switch (E->getLHS()->getType().getObjCLifetime()) {
3814 case Qualifiers::OCL_Strong:
3815 return EmitARCStoreStrong(E, /*ignored*/ false).first;
3817 case Qualifiers::OCL_Autoreleasing:
3818 return EmitARCStoreAutoreleasing(E).first;
3820 // No reason to do any of these differently.
3821 case Qualifiers::OCL_None:
3822 case Qualifiers::OCL_ExplicitNone:
3823 case Qualifiers::OCL_Weak:
3827 RValue RV = EmitAnyExpr(E->getRHS());
3828 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
3829 EmitStoreThroughLValue(RV, LV);
3834 return EmitComplexAssignmentLValue(E);
3837 return EmitAggExprToLValue(E);
3839 llvm_unreachable("bad evaluation kind");
3842 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
3843 RValue RV = EmitCallExpr(E);
3846 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
3847 AlignmentSource::Decl);
3849 assert(E->getCallReturnType(getContext())->isReferenceType() &&
3850 "Can't have a scalar return unless the return type is a "
3853 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
3856 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
3857 // FIXME: This shouldn't require another copy.
3858 return EmitAggExprToLValue(E);
3861 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
3862 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
3863 && "binding l-value to type which needs a temporary");
3864 AggValueSlot Slot = CreateAggTemp(E->getType());
3865 EmitCXXConstructExpr(E, Slot);
3866 return MakeAddrLValue(Slot.getAddress(), E->getType(),
3867 AlignmentSource::Decl);
3871 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
3872 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
3875 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
3876 return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
3877 ConvertType(E->getType()));
3880 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
3881 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
3882 AlignmentSource::Decl);
3886 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
3887 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
3888 Slot.setExternallyDestructed();
3889 EmitAggExpr(E->getSubExpr(), Slot);
3890 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
3891 return MakeAddrLValue(Slot.getAddress(), E->getType(),
3892 AlignmentSource::Decl);
3896 CodeGenFunction::EmitLambdaLValue(const LambdaExpr *E) {
3897 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
3898 EmitLambdaExpr(E, Slot);
3899 return MakeAddrLValue(Slot.getAddress(), E->getType(),
3900 AlignmentSource::Decl);
3903 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
3904 RValue RV = EmitObjCMessageExpr(E);
3907 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
3908 AlignmentSource::Decl);
3910 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
3911 "Can't have a scalar return unless the return type is a "
3914 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
3917 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
3919 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
3920 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
3923 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
3924 const ObjCIvarDecl *Ivar) {
3925 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
3928 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
3929 llvm::Value *BaseValue,
3930 const ObjCIvarDecl *Ivar,
3931 unsigned CVRQualifiers) {
3932 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
3933 Ivar, CVRQualifiers);
3936 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
3937 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
3938 llvm::Value *BaseValue = nullptr;
3939 const Expr *BaseExpr = E->getBase();
3940 Qualifiers BaseQuals;
3943 BaseValue = EmitScalarExpr(BaseExpr);
3944 ObjectTy = BaseExpr->getType()->getPointeeType();
3945 BaseQuals = ObjectTy.getQualifiers();
3947 LValue BaseLV = EmitLValue(BaseExpr);
3948 BaseValue = BaseLV.getPointer();
3949 ObjectTy = BaseExpr->getType();
3950 BaseQuals = ObjectTy.getQualifiers();
3954 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
3955 BaseQuals.getCVRQualifiers());
3956 setObjCGCLValueClass(getContext(), E, LV);
3960 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
3961 // Can only get l-value for message expression returning aggregate type
3962 RValue RV = EmitAnyExprToTemp(E);
3963 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
3964 AlignmentSource::Decl);
3967 RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
3968 const CallExpr *E, ReturnValueSlot ReturnValue,
3969 CGCalleeInfo CalleeInfo, llvm::Value *Chain) {
3970 // Get the actual function type. The callee type will always be a pointer to
3971 // function type or a block pointer type.
3972 assert(CalleeType->isFunctionPointerType() &&
3973 "Call must have function pointer type!");
3975 // Preserve the non-canonical function type because things like exception
3976 // specifications disappear in the canonical type. That information is useful
3977 // to drive the generation of more accurate code for this call later on.
3978 const FunctionProtoType *NonCanonicalFTP = CalleeType->getAs<PointerType>()
3980 ->getAs<FunctionProtoType>();
3982 const Decl *TargetDecl = CalleeInfo.getCalleeDecl();
3984 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
3985 // We can only guarantee that a function is called from the correct
3986 // context/function based on the appropriate target attributes,
3987 // so only check in the case where we have both always_inline and target
3988 // since otherwise we could be making a conditional call after a check for
3989 // the proper cpu features (and it won't cause code generation issues due to
3990 // function based code generation).
3991 if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
3992 TargetDecl->hasAttr<TargetAttr>())
3993 checkTargetFeatures(E, FD);
3995 CalleeType = getContext().getCanonicalType(CalleeType);
3997 const auto *FnType =
3998 cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
4000 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4001 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4002 if (llvm::Constant *PrefixSig =
4003 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
4004 SanitizerScope SanScope(this);
4005 llvm::Constant *FTRTTIConst =
4006 CGM.GetAddrOfRTTIDescriptor(QualType(FnType, 0), /*ForEH=*/true);
4007 llvm::Type *PrefixStructTyElems[] = {
4008 PrefixSig->getType(),
4009 FTRTTIConst->getType()
4011 llvm::StructType *PrefixStructTy = llvm::StructType::get(
4012 CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4014 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4015 Callee, llvm::PointerType::getUnqual(PrefixStructTy));
4016 llvm::Value *CalleeSigPtr =
4017 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4018 llvm::Value *CalleeSig =
4019 Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4020 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4022 llvm::BasicBlock *Cont = createBasicBlock("cont");
4023 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4024 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4026 EmitBlock(TypeCheck);
4027 llvm::Value *CalleeRTTIPtr =
4028 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4029 llvm::Value *CalleeRTTI =
4030 Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4031 llvm::Value *CalleeRTTIMatch =
4032 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4033 llvm::Constant *StaticData[] = {
4034 EmitCheckSourceLocation(E->getLocStart()),
4035 EmitCheckTypeDescriptor(CalleeType)
4037 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4038 "function_type_mismatch", StaticData, Callee);
4040 Builder.CreateBr(Cont);
4045 // If we are checking indirect calls and this call is indirect, check that the
4046 // function pointer is a member of the bit set for the function type.
4047 if (SanOpts.has(SanitizerKind::CFIICall) &&
4048 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4049 SanitizerScope SanScope(this);
4050 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4052 llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4053 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4055 llvm::Value *CastedCallee = Builder.CreateBitCast(Callee, Int8PtrTy);
4056 llvm::Value *TypeTest = Builder.CreateCall(
4057 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4059 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4060 llvm::Constant *StaticData[] = {
4061 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4062 EmitCheckSourceLocation(E->getLocStart()),
4063 EmitCheckTypeDescriptor(QualType(FnType, 0)),
4065 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4066 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4067 CastedCallee, StaticData);
4069 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4070 "cfi_check_fail", StaticData,
4071 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4077 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
4078 CGM.getContext().VoidPtrTy);
4079 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4080 E->getDirectCallee(), /*ParamsToSkip*/ 0);
4082 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
4083 Args, FnType, /*isChainCall=*/Chain);
4086 // If the expression that denotes the called function has a type
4087 // that does not include a prototype, [the default argument
4088 // promotions are performed]. If the number of arguments does not
4089 // equal the number of parameters, the behavior is undefined. If
4090 // the function is defined with a type that includes a prototype,
4091 // and either the prototype ends with an ellipsis (, ...) or the
4092 // types of the arguments after promotion are not compatible with
4093 // the types of the parameters, the behavior is undefined. If the
4094 // function is defined with a type that does not include a
4095 // prototype, and the types of the arguments after promotion are
4096 // not compatible with those of the parameters after promotion,
4097 // the behavior is undefined [except in some trivial cases].
4098 // That is, in the general case, we should assume that a call
4099 // through an unprototyped function type works like a *non-variadic*
4100 // call. The way we make this work is to cast to the exact type
4101 // of the promoted arguments.
4103 // Chain calls use this same code path to add the invisible chain parameter
4104 // to the function type.
4105 if (isa<FunctionNoProtoType>(FnType) || Chain) {
4106 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4107 CalleeTy = CalleeTy->getPointerTo();
4108 Callee = Builder.CreateBitCast(Callee, CalleeTy, "callee.knr.cast");
4111 return EmitCall(FnInfo, Callee, ReturnValue, Args,
4112 CGCalleeInfo(NonCanonicalFTP, TargetDecl));
4115 LValue CodeGenFunction::
4116 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
4117 Address BaseAddr = Address::invalid();
4118 if (E->getOpcode() == BO_PtrMemI) {
4119 BaseAddr = EmitPointerWithAlignment(E->getLHS());
4121 BaseAddr = EmitLValue(E->getLHS()).getAddress();
4124 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4126 const MemberPointerType *MPT
4127 = E->getRHS()->getType()->getAs<MemberPointerType>();
4129 AlignmentSource AlignSource;
4130 Address MemberAddr =
4131 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT,
4134 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), AlignSource);
4137 /// Given the address of a temporary variable, produce an r-value of
4139 RValue CodeGenFunction::convertTempToRValue(Address addr,
4141 SourceLocation loc) {
4142 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
4143 switch (getEvaluationKind(type)) {
4145 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4147 return lvalue.asAggregateRValue();
4149 return RValue::get(EmitLoadOfScalar(lvalue, loc));
4151 llvm_unreachable("bad evaluation kind");
4154 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4155 assert(Val->getType()->isFPOrFPVectorTy());
4156 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4159 llvm::MDBuilder MDHelper(getLLVMContext());
4160 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
4162 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
4166 struct LValueOrRValue {
4172 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
4173 const PseudoObjectExpr *E,
4175 AggValueSlot slot) {
4176 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
4178 // Find the result expression, if any.
4179 const Expr *resultExpr = E->getResultExpr();
4180 LValueOrRValue result;
4182 for (PseudoObjectExpr::const_semantics_iterator
4183 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
4184 const Expr *semantic = *i;
4186 // If this semantic expression is an opaque value, bind it
4187 // to the result of its source expression.
4188 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
4190 // If this is the result expression, we may need to evaluate
4191 // directly into the slot.
4192 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
4194 if (ov == resultExpr && ov->isRValue() && !forLValue &&
4195 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
4196 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
4198 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
4199 AlignmentSource::Decl);
4200 opaqueData = OVMA::bind(CGF, ov, LV);
4201 result.RV = slot.asRValue();
4203 // Otherwise, emit as normal.
4205 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
4207 // If this is the result, also evaluate the result now.
4208 if (ov == resultExpr) {
4210 result.LV = CGF.EmitLValue(ov);
4212 result.RV = CGF.EmitAnyExpr(ov, slot);
4216 opaques.push_back(opaqueData);
4218 // Otherwise, if the expression is the result, evaluate it
4219 // and remember the result.
4220 } else if (semantic == resultExpr) {
4222 result.LV = CGF.EmitLValue(semantic);
4224 result.RV = CGF.EmitAnyExpr(semantic, slot);
4226 // Otherwise, evaluate the expression in an ignored context.
4228 CGF.EmitIgnoredExpr(semantic);
4232 // Unbind all the opaques now.
4233 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
4234 opaques[i].unbind(CGF);
4239 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
4240 AggValueSlot slot) {
4241 return emitPseudoObjectExpr(*this, E, false, slot).RV;
4244 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
4245 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;