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());
364 // We should not have emitted the initializer for this temporary as a
366 assert(!Var->hasInitializer());
367 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
369 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
370 AlignmentSource::Decl);
372 switch (getEvaluationKind(E->getType())) {
373 default: llvm_unreachable("expected scalar or aggregate expression");
375 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
377 case TEK_Aggregate: {
378 EmitAggExpr(E, AggValueSlot::forAddr(Object,
379 E->getType().getQualifiers(),
380 AggValueSlot::IsDestructed,
381 AggValueSlot::DoesNotNeedGCBarriers,
382 AggValueSlot::IsNotAliased));
387 pushTemporaryCleanup(*this, M, E, Object);
391 SmallVector<const Expr *, 2> CommaLHSs;
392 SmallVector<SubobjectAdjustment, 2> Adjustments;
393 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
395 for (const auto &Ignored : CommaLHSs)
396 EmitIgnoredExpr(Ignored);
398 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
399 if (opaque->getType()->isRecordType()) {
400 assert(Adjustments.empty());
401 return EmitOpaqueValueLValue(opaque);
405 // Create and initialize the reference temporary.
406 Address Object = createReferenceTemporary(*this, M, E);
407 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
408 Object = Address(llvm::ConstantExpr::getBitCast(
409 Var, ConvertTypeForMem(E->getType())->getPointerTo()),
410 Object.getAlignment());
411 // If the temporary is a global and has a constant initializer or is a
412 // constant temporary that we promoted to a global, we may have already
414 if (!Var->hasInitializer()) {
415 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
416 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
419 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
421 pushTemporaryCleanup(*this, M, E, Object);
423 // Perform derived-to-base casts and/or field accesses, to get from the
424 // temporary object we created (and, potentially, for which we extended
425 // the lifetime) to the subobject we're binding the reference to.
426 for (unsigned I = Adjustments.size(); I != 0; --I) {
427 SubobjectAdjustment &Adjustment = Adjustments[I-1];
428 switch (Adjustment.Kind) {
429 case SubobjectAdjustment::DerivedToBaseAdjustment:
431 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
432 Adjustment.DerivedToBase.BasePath->path_begin(),
433 Adjustment.DerivedToBase.BasePath->path_end(),
434 /*NullCheckValue=*/ false, E->getExprLoc());
437 case SubobjectAdjustment::FieldAdjustment: {
438 LValue LV = MakeAddrLValue(Object, E->getType(),
439 AlignmentSource::Decl);
440 LV = EmitLValueForField(LV, Adjustment.Field);
441 assert(LV.isSimple() &&
442 "materialized temporary field is not a simple lvalue");
443 Object = LV.getAddress();
447 case SubobjectAdjustment::MemberPointerAdjustment: {
448 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
449 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
456 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
460 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
461 // Emit the expression as an lvalue.
462 LValue LV = EmitLValue(E);
463 assert(LV.isSimple());
464 llvm::Value *Value = LV.getPointer();
466 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
467 // C++11 [dcl.ref]p5 (as amended by core issue 453):
468 // If a glvalue to which a reference is directly bound designates neither
469 // an existing object or function of an appropriate type nor a region of
470 // storage of suitable size and alignment to contain an object of the
471 // reference's type, the behavior is undefined.
472 QualType Ty = E->getType();
473 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
476 return RValue::get(Value);
480 /// getAccessedFieldNo - Given an encoded value and a result number, return the
481 /// input field number being accessed.
482 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
483 const llvm::Constant *Elts) {
484 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
488 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
489 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
491 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
492 llvm::Value *K47 = Builder.getInt64(47);
493 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
494 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
495 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
496 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
497 return Builder.CreateMul(B1, KMul);
500 bool CodeGenFunction::sanitizePerformTypeCheck() const {
501 return SanOpts.has(SanitizerKind::Null) |
502 SanOpts.has(SanitizerKind::Alignment) |
503 SanOpts.has(SanitizerKind::ObjectSize) |
504 SanOpts.has(SanitizerKind::Vptr);
507 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
508 llvm::Value *Ptr, QualType Ty,
509 CharUnits Alignment, bool SkipNullCheck) {
510 if (!sanitizePerformTypeCheck())
513 // Don't check pointers outside the default address space. The null check
514 // isn't correct, the object-size check isn't supported by LLVM, and we can't
515 // communicate the addresses to the runtime handler for the vptr check.
516 if (Ptr->getType()->getPointerAddressSpace())
519 SanitizerScope SanScope(this);
521 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
522 llvm::BasicBlock *Done = nullptr;
524 bool AllowNullPointers = TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
525 TCK == TCK_UpcastToVirtualBase;
526 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
528 // The glvalue must not be an empty glvalue.
529 llvm::Value *IsNonNull = Builder.CreateIsNotNull(Ptr);
531 if (AllowNullPointers) {
532 // When performing pointer casts, it's OK if the value is null.
533 // Skip the remaining checks in that case.
534 Done = createBasicBlock("null");
535 llvm::BasicBlock *Rest = createBasicBlock("not.null");
536 Builder.CreateCondBr(IsNonNull, Rest, Done);
539 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
543 if (SanOpts.has(SanitizerKind::ObjectSize) && !Ty->isIncompleteType()) {
544 uint64_t Size = getContext().getTypeSizeInChars(Ty).getQuantity();
546 // The glvalue must refer to a large enough storage region.
547 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
549 // FIXME: Get object address space
550 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
551 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
552 llvm::Value *Min = Builder.getFalse();
553 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
554 llvm::Value *LargeEnough =
555 Builder.CreateICmpUGE(Builder.CreateCall(F, {CastAddr, Min}),
556 llvm::ConstantInt::get(IntPtrTy, Size));
557 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
560 uint64_t AlignVal = 0;
562 if (SanOpts.has(SanitizerKind::Alignment)) {
563 AlignVal = Alignment.getQuantity();
564 if (!Ty->isIncompleteType() && !AlignVal)
565 AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
567 // The glvalue must be suitably aligned.
570 Builder.CreateAnd(Builder.CreatePtrToInt(Ptr, IntPtrTy),
571 llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
572 llvm::Value *Aligned =
573 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
574 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
578 if (Checks.size() > 0) {
579 llvm::Constant *StaticData[] = {
580 EmitCheckSourceLocation(Loc),
581 EmitCheckTypeDescriptor(Ty),
582 llvm::ConstantInt::get(SizeTy, AlignVal),
583 llvm::ConstantInt::get(Int8Ty, TCK)
585 EmitCheck(Checks, "type_mismatch", StaticData, Ptr);
588 // If possible, check that the vptr indicates that there is a subobject of
589 // type Ty at offset zero within this object.
591 // C++11 [basic.life]p5,6:
592 // [For storage which does not refer to an object within its lifetime]
593 // The program has undefined behavior if:
594 // -- the [pointer or glvalue] is used to access a non-static data member
595 // or call a non-static member function
596 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
597 if (SanOpts.has(SanitizerKind::Vptr) &&
598 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
599 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
600 TCK == TCK_UpcastToVirtualBase) &&
601 RD && RD->hasDefinition() && RD->isDynamicClass()) {
602 // Compute a hash of the mangled name of the type.
604 // FIXME: This is not guaranteed to be deterministic! Move to a
605 // fingerprinting mechanism once LLVM provides one. For the time
606 // being the implementation happens to be deterministic.
607 SmallString<64> MangledName;
608 llvm::raw_svector_ostream Out(MangledName);
609 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
612 // Blacklist based on the mangled type.
613 if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
615 llvm::hash_code TypeHash = hash_value(Out.str());
617 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
618 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
619 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
620 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
621 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
622 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
624 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
625 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
627 // Look the hash up in our cache.
628 const int CacheSize = 128;
629 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
630 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
631 "__ubsan_vptr_type_cache");
632 llvm::Value *Slot = Builder.CreateAnd(Hash,
633 llvm::ConstantInt::get(IntPtrTy,
635 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
636 llvm::Value *CacheVal =
637 Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
640 // If the hash isn't in the cache, call a runtime handler to perform the
641 // hard work of checking whether the vptr is for an object of the right
642 // type. This will either fill in the cache and return, or produce a
644 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
645 llvm::Constant *StaticData[] = {
646 EmitCheckSourceLocation(Loc),
647 EmitCheckTypeDescriptor(Ty),
648 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
649 llvm::ConstantInt::get(Int8Ty, TCK)
651 llvm::Value *DynamicData[] = { Ptr, Hash };
652 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
653 "dynamic_type_cache_miss", StaticData, DynamicData);
658 Builder.CreateBr(Done);
663 /// Determine whether this expression refers to a flexible array member in a
664 /// struct. We disable array bounds checks for such members.
665 static bool isFlexibleArrayMemberExpr(const Expr *E) {
666 // For compatibility with existing code, we treat arrays of length 0 or
667 // 1 as flexible array members.
668 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
669 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
670 if (CAT->getSize().ugt(1))
672 } else if (!isa<IncompleteArrayType>(AT))
675 E = E->IgnoreParens();
677 // A flexible array member must be the last member in the class.
678 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
679 // FIXME: If the base type of the member expr is not FD->getParent(),
680 // this should not be treated as a flexible array member access.
681 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
682 RecordDecl::field_iterator FI(
683 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
684 return ++FI == FD->getParent()->field_end();
691 /// If Base is known to point to the start of an array, return the length of
692 /// that array. Return 0 if the length cannot be determined.
693 static llvm::Value *getArrayIndexingBound(
694 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
695 // For the vector indexing extension, the bound is the number of elements.
696 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
697 IndexedType = Base->getType();
698 return CGF.Builder.getInt32(VT->getNumElements());
701 Base = Base->IgnoreParens();
703 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
704 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
705 !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
706 IndexedType = CE->getSubExpr()->getType();
707 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
708 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
709 return CGF.Builder.getInt(CAT->getSize());
710 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
711 return CGF.getVLASize(VAT).first;
718 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
719 llvm::Value *Index, QualType IndexType,
721 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
722 "should not be called unless adding bounds checks");
723 SanitizerScope SanScope(this);
725 QualType IndexedType;
726 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
730 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
731 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
732 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
734 llvm::Constant *StaticData[] = {
735 EmitCheckSourceLocation(E->getExprLoc()),
736 EmitCheckTypeDescriptor(IndexedType),
737 EmitCheckTypeDescriptor(IndexType)
739 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
740 : Builder.CreateICmpULE(IndexVal, BoundVal);
741 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds), "out_of_bounds",
746 CodeGenFunction::ComplexPairTy CodeGenFunction::
747 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
748 bool isInc, bool isPre) {
749 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
751 llvm::Value *NextVal;
752 if (isa<llvm::IntegerType>(InVal.first->getType())) {
753 uint64_t AmountVal = isInc ? 1 : -1;
754 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
756 // Add the inc/dec to the real part.
757 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
759 QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType();
760 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
763 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
765 // Add the inc/dec to the real part.
766 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
769 ComplexPairTy IncVal(NextVal, InVal.second);
771 // Store the updated result through the lvalue.
772 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
774 // If this is a postinc, return the value read from memory, otherwise use the
776 return isPre ? IncVal : InVal;
779 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
780 CodeGenFunction *CGF) {
781 // Bind VLAs in the cast type.
782 if (CGF && E->getType()->isVariablyModifiedType())
783 CGF->EmitVariablyModifiedType(E->getType());
785 if (CGDebugInfo *DI = getModuleDebugInfo())
786 DI->EmitExplicitCastType(E->getType());
789 //===----------------------------------------------------------------------===//
790 // LValue Expression Emission
791 //===----------------------------------------------------------------------===//
793 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
794 /// derive a more accurate bound on the alignment of the pointer.
795 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
796 AlignmentSource *Source) {
797 // We allow this with ObjC object pointers because of fragile ABIs.
798 assert(E->getType()->isPointerType() ||
799 E->getType()->isObjCObjectPointerType());
800 E = E->IgnoreParens();
803 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
804 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
805 CGM.EmitExplicitCastExprType(ECE, this);
807 switch (CE->getCastKind()) {
808 // Non-converting casts (but not C's implicit conversion from void*).
811 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
812 if (PtrTy->getPointeeType()->isVoidType())
815 AlignmentSource InnerSource;
816 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), &InnerSource);
817 if (Source) *Source = InnerSource;
819 // If this is an explicit bitcast, and the source l-value is
820 // opaque, honor the alignment of the casted-to type.
821 if (isa<ExplicitCastExpr>(CE) &&
822 InnerSource != AlignmentSource::Decl) {
823 Addr = Address(Addr.getPointer(),
824 getNaturalPointeeTypeAlignment(E->getType(), Source));
827 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
828 CE->getCastKind() == CK_BitCast) {
829 if (auto PT = E->getType()->getAs<PointerType>())
830 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
832 CodeGenFunction::CFITCK_UnrelatedCast,
836 return Builder.CreateBitCast(Addr, ConvertType(E->getType()));
840 // Array-to-pointer decay.
841 case CK_ArrayToPointerDecay:
842 return EmitArrayToPointerDecay(CE->getSubExpr(), Source);
844 // Derived-to-base conversions.
845 case CK_UncheckedDerivedToBase:
846 case CK_DerivedToBase: {
847 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), Source);
848 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
849 return GetAddressOfBaseClass(Addr, Derived,
850 CE->path_begin(), CE->path_end(),
851 ShouldNullCheckClassCastValue(CE),
855 // TODO: Is there any reason to treat base-to-derived conversions
863 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
864 if (UO->getOpcode() == UO_AddrOf) {
865 LValue LV = EmitLValue(UO->getSubExpr());
866 if (Source) *Source = LV.getAlignmentSource();
867 return LV.getAddress();
871 // TODO: conditional operators, comma.
873 // Otherwise, use the alignment of the type.
874 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), Source);
875 return Address(EmitScalarExpr(E), Align);
878 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
879 if (Ty->isVoidType())
880 return RValue::get(nullptr);
882 switch (getEvaluationKind(Ty)) {
885 ConvertType(Ty->castAs<ComplexType>()->getElementType());
886 llvm::Value *U = llvm::UndefValue::get(EltTy);
887 return RValue::getComplex(std::make_pair(U, U));
890 // If this is a use of an undefined aggregate type, the aggregate must have an
891 // identifiable address. Just because the contents of the value are undefined
892 // doesn't mean that the address can't be taken and compared.
893 case TEK_Aggregate: {
894 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
895 return RValue::getAggregate(DestPtr);
899 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
901 llvm_unreachable("bad evaluation kind");
904 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
906 ErrorUnsupported(E, Name);
907 return GetUndefRValue(E->getType());
910 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
912 ErrorUnsupported(E, Name);
913 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
914 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
918 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
920 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
921 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
924 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple())
925 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(),
926 E->getType(), LV.getAlignment());
930 /// EmitLValue - Emit code to compute a designator that specifies the location
931 /// of the expression.
933 /// This can return one of two things: a simple address or a bitfield reference.
934 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
935 /// an LLVM pointer type.
937 /// If this returns a bitfield reference, nothing about the pointee type of the
938 /// LLVM value is known: For example, it may not be a pointer to an integer.
940 /// If this returns a normal address, and if the lvalue's C type is fixed size,
941 /// this method guarantees that the returned pointer type will point to an LLVM
942 /// type of the same size of the lvalue's type. If the lvalue has a variable
943 /// length type, this is not possible.
945 LValue CodeGenFunction::EmitLValue(const Expr *E) {
946 ApplyDebugLocation DL(*this, E);
947 switch (E->getStmtClass()) {
948 default: return EmitUnsupportedLValue(E, "l-value expression");
950 case Expr::ObjCPropertyRefExprClass:
951 llvm_unreachable("cannot emit a property reference directly");
953 case Expr::ObjCSelectorExprClass:
954 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
955 case Expr::ObjCIsaExprClass:
956 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
957 case Expr::BinaryOperatorClass:
958 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
959 case Expr::CompoundAssignOperatorClass: {
960 QualType Ty = E->getType();
961 if (const AtomicType *AT = Ty->getAs<AtomicType>())
962 Ty = AT->getValueType();
963 if (!Ty->isAnyComplexType())
964 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
965 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
967 case Expr::CallExprClass:
968 case Expr::CXXMemberCallExprClass:
969 case Expr::CXXOperatorCallExprClass:
970 case Expr::UserDefinedLiteralClass:
971 return EmitCallExprLValue(cast<CallExpr>(E));
972 case Expr::VAArgExprClass:
973 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
974 case Expr::DeclRefExprClass:
975 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
976 case Expr::ParenExprClass:
977 return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
978 case Expr::GenericSelectionExprClass:
979 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
980 case Expr::PredefinedExprClass:
981 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
982 case Expr::StringLiteralClass:
983 return EmitStringLiteralLValue(cast<StringLiteral>(E));
984 case Expr::ObjCEncodeExprClass:
985 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
986 case Expr::PseudoObjectExprClass:
987 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
988 case Expr::InitListExprClass:
989 return EmitInitListLValue(cast<InitListExpr>(E));
990 case Expr::CXXTemporaryObjectExprClass:
991 case Expr::CXXConstructExprClass:
992 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
993 case Expr::CXXBindTemporaryExprClass:
994 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
995 case Expr::CXXUuidofExprClass:
996 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
997 case Expr::LambdaExprClass:
998 return EmitLambdaLValue(cast<LambdaExpr>(E));
1000 case Expr::ExprWithCleanupsClass: {
1001 const auto *cleanups = cast<ExprWithCleanups>(E);
1002 enterFullExpression(cleanups);
1003 RunCleanupsScope Scope(*this);
1004 return EmitLValue(cleanups->getSubExpr());
1007 case Expr::CXXDefaultArgExprClass:
1008 return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr());
1009 case Expr::CXXDefaultInitExprClass: {
1010 CXXDefaultInitExprScope Scope(*this);
1011 return EmitLValue(cast<CXXDefaultInitExpr>(E)->getExpr());
1013 case Expr::CXXTypeidExprClass:
1014 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1016 case Expr::ObjCMessageExprClass:
1017 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1018 case Expr::ObjCIvarRefExprClass:
1019 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1020 case Expr::StmtExprClass:
1021 return EmitStmtExprLValue(cast<StmtExpr>(E));
1022 case Expr::UnaryOperatorClass:
1023 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1024 case Expr::ArraySubscriptExprClass:
1025 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1026 case Expr::OMPArraySectionExprClass:
1027 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1028 case Expr::ExtVectorElementExprClass:
1029 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1030 case Expr::MemberExprClass:
1031 return EmitMemberExpr(cast<MemberExpr>(E));
1032 case Expr::CompoundLiteralExprClass:
1033 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1034 case Expr::ConditionalOperatorClass:
1035 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1036 case Expr::BinaryConditionalOperatorClass:
1037 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1038 case Expr::ChooseExprClass:
1039 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1040 case Expr::OpaqueValueExprClass:
1041 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1042 case Expr::SubstNonTypeTemplateParmExprClass:
1043 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1044 case Expr::ImplicitCastExprClass:
1045 case Expr::CStyleCastExprClass:
1046 case Expr::CXXFunctionalCastExprClass:
1047 case Expr::CXXStaticCastExprClass:
1048 case Expr::CXXDynamicCastExprClass:
1049 case Expr::CXXReinterpretCastExprClass:
1050 case Expr::CXXConstCastExprClass:
1051 case Expr::ObjCBridgedCastExprClass:
1052 return EmitCastLValue(cast<CastExpr>(E));
1054 case Expr::MaterializeTemporaryExprClass:
1055 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1059 /// Given an object of the given canonical type, can we safely copy a
1060 /// value out of it based on its initializer?
1061 static bool isConstantEmittableObjectType(QualType type) {
1062 assert(type.isCanonical());
1063 assert(!type->isReferenceType());
1065 // Must be const-qualified but non-volatile.
1066 Qualifiers qs = type.getLocalQualifiers();
1067 if (!qs.hasConst() || qs.hasVolatile()) return false;
1069 // Otherwise, all object types satisfy this except C++ classes with
1070 // mutable subobjects or non-trivial copy/destroy behavior.
1071 if (const auto *RT = dyn_cast<RecordType>(type))
1072 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1073 if (RD->hasMutableFields() || !RD->isTrivial())
1079 /// Can we constant-emit a load of a reference to a variable of the
1080 /// given type? This is different from predicates like
1081 /// Decl::isUsableInConstantExpressions because we do want it to apply
1082 /// in situations that don't necessarily satisfy the language's rules
1083 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1084 /// to do this with const float variables even if those variables
1085 /// aren't marked 'constexpr'.
1086 enum ConstantEmissionKind {
1088 CEK_AsReferenceOnly,
1089 CEK_AsValueOrReference,
1092 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1093 type = type.getCanonicalType();
1094 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1095 if (isConstantEmittableObjectType(ref->getPointeeType()))
1096 return CEK_AsValueOrReference;
1097 return CEK_AsReferenceOnly;
1099 if (isConstantEmittableObjectType(type))
1100 return CEK_AsValueOnly;
1104 /// Try to emit a reference to the given value without producing it as
1105 /// an l-value. This is actually more than an optimization: we can't
1106 /// produce an l-value for variables that we never actually captured
1107 /// in a block or lambda, which means const int variables or constexpr
1108 /// literals or similar.
1109 CodeGenFunction::ConstantEmission
1110 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1111 ValueDecl *value = refExpr->getDecl();
1113 // The value needs to be an enum constant or a constant variable.
1114 ConstantEmissionKind CEK;
1115 if (isa<ParmVarDecl>(value)) {
1117 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1118 CEK = checkVarTypeForConstantEmission(var->getType());
1119 } else if (isa<EnumConstantDecl>(value)) {
1120 CEK = CEK_AsValueOnly;
1124 if (CEK == CEK_None) return ConstantEmission();
1126 Expr::EvalResult result;
1127 bool resultIsReference;
1128 QualType resultType;
1130 // It's best to evaluate all the way as an r-value if that's permitted.
1131 if (CEK != CEK_AsReferenceOnly &&
1132 refExpr->EvaluateAsRValue(result, getContext())) {
1133 resultIsReference = false;
1134 resultType = refExpr->getType();
1136 // Otherwise, try to evaluate as an l-value.
1137 } else if (CEK != CEK_AsValueOnly &&
1138 refExpr->EvaluateAsLValue(result, getContext())) {
1139 resultIsReference = true;
1140 resultType = value->getType();
1144 return ConstantEmission();
1147 // In any case, if the initializer has side-effects, abandon ship.
1148 if (result.HasSideEffects)
1149 return ConstantEmission();
1151 // Emit as a constant.
1152 llvm::Constant *C = CGM.EmitConstantValue(result.Val, resultType, this);
1154 // Make sure we emit a debug reference to the global variable.
1155 // This should probably fire even for
1156 if (isa<VarDecl>(value)) {
1157 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1158 EmitDeclRefExprDbgValue(refExpr, C);
1160 assert(isa<EnumConstantDecl>(value));
1161 EmitDeclRefExprDbgValue(refExpr, C);
1164 // If we emitted a reference constant, we need to dereference that.
1165 if (resultIsReference)
1166 return ConstantEmission::forReference(C);
1168 return ConstantEmission::forValue(C);
1171 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1172 SourceLocation Loc) {
1173 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1174 lvalue.getType(), Loc, lvalue.getAlignmentSource(),
1175 lvalue.getTBAAInfo(),
1176 lvalue.getTBAABaseType(), lvalue.getTBAAOffset(),
1177 lvalue.isNontemporal());
1180 static bool hasBooleanRepresentation(QualType Ty) {
1181 if (Ty->isBooleanType())
1184 if (const EnumType *ET = Ty->getAs<EnumType>())
1185 return ET->getDecl()->getIntegerType()->isBooleanType();
1187 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1188 return hasBooleanRepresentation(AT->getValueType());
1193 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1194 llvm::APInt &Min, llvm::APInt &End,
1196 const EnumType *ET = Ty->getAs<EnumType>();
1197 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1198 ET && !ET->getDecl()->isFixed();
1199 bool IsBool = hasBooleanRepresentation(Ty);
1200 if (!IsBool && !IsRegularCPlusPlusEnum)
1204 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1205 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1207 const EnumDecl *ED = ET->getDecl();
1208 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1209 unsigned Bitwidth = LTy->getScalarSizeInBits();
1210 unsigned NumNegativeBits = ED->getNumNegativeBits();
1211 unsigned NumPositiveBits = ED->getNumPositiveBits();
1213 if (NumNegativeBits) {
1214 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1215 assert(NumBits <= Bitwidth);
1216 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1219 assert(NumPositiveBits <= Bitwidth);
1220 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1221 Min = llvm::APInt(Bitwidth, 0);
1227 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1228 llvm::APInt Min, End;
1229 if (!getRangeForType(*this, Ty, Min, End,
1230 CGM.getCodeGenOpts().StrictEnums))
1233 llvm::MDBuilder MDHelper(getLLVMContext());
1234 return MDHelper.createRange(Min, End);
1237 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1240 AlignmentSource AlignSource,
1241 llvm::MDNode *TBAAInfo,
1242 QualType TBAABaseType,
1243 uint64_t TBAAOffset,
1244 bool isNontemporal) {
1245 // For better performance, handle vector loads differently.
1246 if (Ty->isVectorType()) {
1247 const llvm::Type *EltTy = Addr.getElementType();
1249 const auto *VTy = cast<llvm::VectorType>(EltTy);
1251 // Handle vectors of size 3 like size 4 for better performance.
1252 if (VTy->getNumElements() == 3) {
1254 // Bitcast to vec4 type.
1255 llvm::VectorType *vec4Ty = llvm::VectorType::get(VTy->getElementType(),
1257 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1259 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1261 // Shuffle vector to get vec3.
1262 V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1263 {0, 1, 2}, "extractVec");
1264 return EmitFromMemory(V, Ty);
1268 // Atomic operations have to be done on integral types.
1269 if (Ty->isAtomicType() || typeIsSuitableForInlineAtomic(Ty, Volatile)) {
1271 LValue::MakeAddr(Addr, Ty, getContext(), AlignSource, TBAAInfo);
1272 return EmitAtomicLoad(lvalue, Loc).getScalarVal();
1275 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1276 if (isNontemporal) {
1277 llvm::MDNode *Node = llvm::MDNode::get(
1278 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1279 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1282 llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
1285 CGM.DecorateInstructionWithTBAA(Load, TBAAPath,
1286 false /*ConvertTypeToTag*/);
1289 bool NeedsBoolCheck =
1290 SanOpts.has(SanitizerKind::Bool) && hasBooleanRepresentation(Ty);
1291 bool NeedsEnumCheck =
1292 SanOpts.has(SanitizerKind::Enum) && Ty->getAs<EnumType>();
1293 if (NeedsBoolCheck || NeedsEnumCheck) {
1294 SanitizerScope SanScope(this);
1295 llvm::APInt Min, End;
1296 if (getRangeForType(*this, Ty, Min, End, true)) {
1300 Check = Builder.CreateICmpULE(
1301 Load, llvm::ConstantInt::get(getLLVMContext(), End));
1303 llvm::Value *Upper = Builder.CreateICmpSLE(
1304 Load, llvm::ConstantInt::get(getLLVMContext(), End));
1305 llvm::Value *Lower = Builder.CreateICmpSGE(
1306 Load, llvm::ConstantInt::get(getLLVMContext(), Min));
1307 Check = Builder.CreateAnd(Upper, Lower);
1309 llvm::Constant *StaticArgs[] = {
1310 EmitCheckSourceLocation(Loc),
1311 EmitCheckTypeDescriptor(Ty)
1313 SanitizerMask Kind = NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1314 EmitCheck(std::make_pair(Check, Kind), "load_invalid_value", StaticArgs,
1315 EmitCheckValue(Load));
1317 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1318 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1319 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1321 return EmitFromMemory(Load, Ty);
1324 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1325 // Bool has a different representation in memory than in registers.
1326 if (hasBooleanRepresentation(Ty)) {
1327 // This should really always be an i1, but sometimes it's already
1328 // an i8, and it's awkward to track those cases down.
1329 if (Value->getType()->isIntegerTy(1))
1330 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1331 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1332 "wrong value rep of bool");
1338 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1339 // Bool has a different representation in memory than in registers.
1340 if (hasBooleanRepresentation(Ty)) {
1341 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1342 "wrong value rep of bool");
1343 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1349 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1350 bool Volatile, QualType Ty,
1351 AlignmentSource AlignSource,
1352 llvm::MDNode *TBAAInfo,
1353 bool isInit, QualType TBAABaseType,
1354 uint64_t TBAAOffset,
1355 bool isNontemporal) {
1357 // Handle vectors differently to get better performance.
1358 if (Ty->isVectorType()) {
1359 llvm::Type *SrcTy = Value->getType();
1360 auto *VecTy = cast<llvm::VectorType>(SrcTy);
1361 // Handle vec3 special.
1362 if (VecTy->getNumElements() == 3) {
1363 // Our source is a vec3, do a shuffle vector to make it a vec4.
1364 llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1365 Builder.getInt32(2),
1366 llvm::UndefValue::get(Builder.getInt32Ty())};
1367 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1368 Value = Builder.CreateShuffleVector(Value,
1369 llvm::UndefValue::get(VecTy),
1370 MaskV, "extractVec");
1371 SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1373 if (Addr.getElementType() != SrcTy) {
1374 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1378 Value = EmitToMemory(Value, Ty);
1380 if (Ty->isAtomicType() ||
1381 (!isInit && typeIsSuitableForInlineAtomic(Ty, Volatile))) {
1382 EmitAtomicStore(RValue::get(Value),
1383 LValue::MakeAddr(Addr, Ty, getContext(),
1384 AlignSource, TBAAInfo),
1389 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1390 if (isNontemporal) {
1391 llvm::MDNode *Node =
1392 llvm::MDNode::get(Store->getContext(),
1393 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1394 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1397 llvm::MDNode *TBAAPath = CGM.getTBAAStructTagInfo(TBAABaseType, TBAAInfo,
1400 CGM.DecorateInstructionWithTBAA(Store, TBAAPath,
1401 false /*ConvertTypeToTag*/);
1405 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1407 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
1408 lvalue.getType(), lvalue.getAlignmentSource(),
1409 lvalue.getTBAAInfo(), isInit, lvalue.getTBAABaseType(),
1410 lvalue.getTBAAOffset(), lvalue.isNontemporal());
1413 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1414 /// method emits the address of the lvalue, then loads the result as an rvalue,
1415 /// returning the rvalue.
1416 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1417 if (LV.isObjCWeak()) {
1418 // load of a __weak object.
1419 Address AddrWeakObj = LV.getAddress();
1420 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1423 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1424 // In MRC mode, we do a load+autorelease.
1425 if (!getLangOpts().ObjCAutoRefCount) {
1426 return RValue::get(EmitARCLoadWeak(LV.getAddress()));
1429 // In ARC mode, we load retained and then consume the value.
1430 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
1431 Object = EmitObjCConsumeObject(LV.getType(), Object);
1432 return RValue::get(Object);
1435 if (LV.isSimple()) {
1436 assert(!LV.getType()->isFunctionType());
1438 // Everything needs a load.
1439 return RValue::get(EmitLoadOfScalar(LV, Loc));
1442 if (LV.isVectorElt()) {
1443 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1444 LV.isVolatileQualified());
1445 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1449 // If this is a reference to a subset of the elements of a vector, either
1450 // shuffle the input or extract/insert them as appropriate.
1451 if (LV.isExtVectorElt())
1452 return EmitLoadOfExtVectorElementLValue(LV);
1454 // Global Register variables always invoke intrinsics
1455 if (LV.isGlobalReg())
1456 return EmitLoadOfGlobalRegLValue(LV);
1458 assert(LV.isBitField() && "Unknown LValue type!");
1459 return EmitLoadOfBitfieldLValue(LV);
1462 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV) {
1463 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1465 // Get the output type.
1466 llvm::Type *ResLTy = ConvertType(LV.getType());
1468 Address Ptr = LV.getBitFieldAddress();
1469 llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1471 if (Info.IsSigned) {
1472 assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1473 unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1475 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1476 if (Info.Offset + HighBits)
1477 Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1480 Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1481 if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1482 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1486 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1488 return RValue::get(Val);
1491 // If this is a reference to a subset of the elements of a vector, create an
1492 // appropriate shufflevector.
1493 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1494 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1495 LV.isVolatileQualified());
1497 const llvm::Constant *Elts = LV.getExtVectorElts();
1499 // If the result of the expression is a non-vector type, we must be extracting
1500 // a single element. Just codegen as an extractelement.
1501 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1503 unsigned InIdx = getAccessedFieldNo(0, Elts);
1504 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1505 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1508 // Always use shuffle vector to try to retain the original program structure
1509 unsigned NumResultElts = ExprVT->getNumElements();
1511 SmallVector<llvm::Constant*, 4> Mask;
1512 for (unsigned i = 0; i != NumResultElts; ++i)
1513 Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1515 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1516 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1518 return RValue::get(Vec);
1521 /// @brief Generates lvalue for partial ext_vector access.
1522 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
1523 Address VectorAddress = LV.getExtVectorAddress();
1524 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1525 QualType EQT = ExprVT->getElementType();
1526 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1528 Address CastToPointerElement =
1529 Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1530 "conv.ptr.element");
1532 const llvm::Constant *Elts = LV.getExtVectorElts();
1533 unsigned ix = getAccessedFieldNo(0, Elts);
1535 Address VectorBasePtrPlusIx =
1536 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1537 getContext().getTypeSizeInChars(EQT),
1540 return VectorBasePtrPlusIx;
1543 /// @brief Load of global gamed gegisters are always calls to intrinsics.
1544 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
1545 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1546 "Bad type for register variable");
1547 llvm::MDNode *RegName = cast<llvm::MDNode>(
1548 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1550 // We accept integer and pointer types only
1551 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1552 llvm::Type *Ty = OrigTy;
1553 if (OrigTy->isPointerTy())
1554 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1555 llvm::Type *Types[] = { Ty };
1557 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1558 llvm::Value *Call = Builder.CreateCall(
1559 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1560 if (OrigTy->isPointerTy())
1561 Call = Builder.CreateIntToPtr(Call, OrigTy);
1562 return RValue::get(Call);
1566 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1567 /// lvalue, where both are guaranteed to the have the same type, and that type
1569 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
1571 if (!Dst.isSimple()) {
1572 if (Dst.isVectorElt()) {
1573 // Read/modify/write the vector, inserting the new element.
1574 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
1575 Dst.isVolatileQualified());
1576 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1577 Dst.getVectorIdx(), "vecins");
1578 Builder.CreateStore(Vec, Dst.getVectorAddress(),
1579 Dst.isVolatileQualified());
1583 // If this is an update of extended vector elements, insert them as
1585 if (Dst.isExtVectorElt())
1586 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
1588 if (Dst.isGlobalReg())
1589 return EmitStoreThroughGlobalRegLValue(Src, Dst);
1591 assert(Dst.isBitField() && "Unknown LValue type");
1592 return EmitStoreThroughBitfieldLValue(Src, Dst);
1595 // There's special magic for assigning into an ARC-qualified l-value.
1596 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1598 case Qualifiers::OCL_None:
1599 llvm_unreachable("present but none");
1601 case Qualifiers::OCL_ExplicitNone:
1605 case Qualifiers::OCL_Strong:
1606 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1609 case Qualifiers::OCL_Weak:
1610 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true);
1613 case Qualifiers::OCL_Autoreleasing:
1614 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
1615 Src.getScalarVal()));
1616 // fall into the normal path
1621 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1622 // load of a __weak object.
1623 Address LvalueDst = Dst.getAddress();
1624 llvm::Value *src = Src.getScalarVal();
1625 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1629 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1630 // load of a __strong object.
1631 Address LvalueDst = Dst.getAddress();
1632 llvm::Value *src = Src.getScalarVal();
1633 if (Dst.isObjCIvar()) {
1634 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
1635 llvm::Type *ResultType = IntPtrTy;
1636 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
1637 llvm::Value *RHS = dst.getPointer();
1638 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
1640 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
1641 "sub.ptr.lhs.cast");
1642 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
1643 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
1645 } else if (Dst.isGlobalObjCRef()) {
1646 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
1647 Dst.isThreadLocalRef());
1650 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
1654 assert(Src.isScalar() && "Can't emit an agg store with this method");
1655 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
1658 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
1659 llvm::Value **Result) {
1660 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
1661 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
1662 Address Ptr = Dst.getBitFieldAddress();
1664 // Get the source value, truncated to the width of the bit-field.
1665 llvm::Value *SrcVal = Src.getScalarVal();
1667 // Cast the source to the storage type and shift it into place.
1668 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
1669 /*IsSigned=*/false);
1670 llvm::Value *MaskedVal = SrcVal;
1672 // See if there are other bits in the bitfield's storage we'll need to load
1673 // and mask together with source before storing.
1674 if (Info.StorageSize != Info.Size) {
1675 assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
1677 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
1679 // Mask the source value as needed.
1680 if (!hasBooleanRepresentation(Dst.getType()))
1681 SrcVal = Builder.CreateAnd(SrcVal,
1682 llvm::APInt::getLowBitsSet(Info.StorageSize,
1687 SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
1689 // Mask out the original value.
1690 Val = Builder.CreateAnd(Val,
1691 ~llvm::APInt::getBitsSet(Info.StorageSize,
1693 Info.Offset + Info.Size),
1696 // Or together the unchanged values and the source value.
1697 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
1699 assert(Info.Offset == 0);
1702 // Write the new value back out.
1703 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
1705 // Return the new value of the bit-field, if requested.
1707 llvm::Value *ResultVal = MaskedVal;
1709 // Sign extend the value if needed.
1710 if (Info.IsSigned) {
1711 assert(Info.Size <= Info.StorageSize);
1712 unsigned HighBits = Info.StorageSize - Info.Size;
1714 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
1715 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
1719 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
1721 *Result = EmitFromMemory(ResultVal, Dst.getType());
1725 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
1727 // This access turns into a read/modify/write of the vector. Load the input
1729 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
1730 Dst.isVolatileQualified());
1731 const llvm::Constant *Elts = Dst.getExtVectorElts();
1733 llvm::Value *SrcVal = Src.getScalarVal();
1735 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
1736 unsigned NumSrcElts = VTy->getNumElements();
1737 unsigned NumDstElts =
1738 cast<llvm::VectorType>(Vec->getType())->getNumElements();
1739 if (NumDstElts == NumSrcElts) {
1740 // Use shuffle vector is the src and destination are the same number of
1741 // elements and restore the vector mask since it is on the side it will be
1743 SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
1744 for (unsigned i = 0; i != NumSrcElts; ++i)
1745 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
1747 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1748 Vec = Builder.CreateShuffleVector(SrcVal,
1749 llvm::UndefValue::get(Vec->getType()),
1751 } else if (NumDstElts > NumSrcElts) {
1752 // Extended the source vector to the same length and then shuffle it
1753 // into the destination.
1754 // FIXME: since we're shuffling with undef, can we just use the indices
1755 // into that? This could be simpler.
1756 SmallVector<llvm::Constant*, 4> ExtMask;
1757 for (unsigned i = 0; i != NumSrcElts; ++i)
1758 ExtMask.push_back(Builder.getInt32(i));
1759 ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
1760 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
1761 llvm::Value *ExtSrcVal =
1762 Builder.CreateShuffleVector(SrcVal,
1763 llvm::UndefValue::get(SrcVal->getType()),
1766 SmallVector<llvm::Constant*, 4> Mask;
1767 for (unsigned i = 0; i != NumDstElts; ++i)
1768 Mask.push_back(Builder.getInt32(i));
1770 // When the vector size is odd and .odd or .hi is used, the last element
1771 // of the Elts constant array will be one past the size of the vector.
1772 // Ignore the last element here, if it is greater than the mask size.
1773 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
1776 // modify when what gets shuffled in
1777 for (unsigned i = 0; i != NumSrcElts; ++i)
1778 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
1779 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1780 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
1782 // We should never shorten the vector
1783 llvm_unreachable("unexpected shorten vector length");
1786 // If the Src is a scalar (not a vector) it must be updating one element.
1787 unsigned InIdx = getAccessedFieldNo(0, Elts);
1788 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1789 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
1792 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
1793 Dst.isVolatileQualified());
1796 /// @brief Store of global named registers are always calls to intrinsics.
1797 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
1798 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
1799 "Bad type for register variable");
1800 llvm::MDNode *RegName = cast<llvm::MDNode>(
1801 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
1802 assert(RegName && "Register LValue is not metadata");
1804 // We accept integer and pointer types only
1805 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
1806 llvm::Type *Ty = OrigTy;
1807 if (OrigTy->isPointerTy())
1808 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1809 llvm::Type *Types[] = { Ty };
1811 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
1812 llvm::Value *Value = Src.getScalarVal();
1813 if (OrigTy->isPointerTy())
1814 Value = Builder.CreatePtrToInt(Value, Ty);
1816 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
1819 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
1820 // generating write-barries API. It is currently a global, ivar,
1822 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
1824 bool IsMemberAccess=false) {
1825 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
1828 if (isa<ObjCIvarRefExpr>(E)) {
1829 QualType ExpTy = E->getType();
1830 if (IsMemberAccess && ExpTy->isPointerType()) {
1831 // If ivar is a structure pointer, assigning to field of
1832 // this struct follows gcc's behavior and makes it a non-ivar
1833 // writer-barrier conservatively.
1834 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1835 if (ExpTy->isRecordType()) {
1836 LV.setObjCIvar(false);
1840 LV.setObjCIvar(true);
1841 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
1842 LV.setBaseIvarExp(Exp->getBase());
1843 LV.setObjCArray(E->getType()->isArrayType());
1847 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
1848 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
1849 if (VD->hasGlobalStorage()) {
1850 LV.setGlobalObjCRef(true);
1851 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
1854 LV.setObjCArray(E->getType()->isArrayType());
1858 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
1859 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1863 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
1864 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1865 if (LV.isObjCIvar()) {
1866 // If cast is to a structure pointer, follow gcc's behavior and make it
1867 // a non-ivar write-barrier.
1868 QualType ExpTy = E->getType();
1869 if (ExpTy->isPointerType())
1870 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType();
1871 if (ExpTy->isRecordType())
1872 LV.setObjCIvar(false);
1877 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
1878 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
1882 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
1883 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1887 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
1888 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1892 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
1893 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
1897 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
1898 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
1899 if (LV.isObjCIvar() && !LV.isObjCArray())
1900 // Using array syntax to assigning to what an ivar points to is not
1901 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
1902 LV.setObjCIvar(false);
1903 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
1904 // Using array syntax to assigning to what global points to is not
1905 // same as assigning to the global itself. {id *G;} G[i] = 0;
1906 LV.setGlobalObjCRef(false);
1910 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
1911 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
1912 // We don't know if member is an 'ivar', but this flag is looked at
1913 // only in the context of LV.isObjCIvar().
1914 LV.setObjCArray(E->getType()->isArrayType());
1919 static llvm::Value *
1920 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
1921 llvm::Value *V, llvm::Type *IRType,
1922 StringRef Name = StringRef()) {
1923 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
1924 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
1927 static LValue EmitThreadPrivateVarDeclLValue(
1928 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
1929 llvm::Type *RealVarTy, SourceLocation Loc) {
1930 Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
1931 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
1932 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
1935 Address CodeGenFunction::EmitLoadOfReference(Address Addr,
1936 const ReferenceType *RefTy,
1937 AlignmentSource *Source) {
1938 llvm::Value *Ptr = Builder.CreateLoad(Addr);
1939 return Address(Ptr, getNaturalTypeAlignment(RefTy->getPointeeType(),
1940 Source, /*forPointee*/ true));
1944 LValue CodeGenFunction::EmitLoadOfReferenceLValue(Address RefAddr,
1945 const ReferenceType *RefTy) {
1946 AlignmentSource Source;
1947 Address Addr = EmitLoadOfReference(RefAddr, RefTy, &Source);
1948 return MakeAddrLValue(Addr, RefTy->getPointeeType(), Source);
1951 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
1952 const PointerType *PtrTy,
1953 AlignmentSource *Source) {
1954 llvm::Value *Addr = Builder.CreateLoad(Ptr);
1955 return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(), Source,
1956 /*forPointeeType=*/true));
1959 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
1960 const PointerType *PtrTy) {
1961 AlignmentSource Source;
1962 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &Source);
1963 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), Source);
1966 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
1967 const Expr *E, const VarDecl *VD) {
1968 QualType T = E->getType();
1970 // If it's thread_local, emit a call to its wrapper function instead.
1971 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
1972 CGF.CGM.getCXXABI().usesThreadWrapperFunction())
1973 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
1975 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
1976 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
1977 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
1978 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
1979 Address Addr(V, Alignment);
1981 // Emit reference to the private copy of the variable if it is an OpenMP
1982 // threadprivate variable.
1983 if (CGF.getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>())
1984 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
1986 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
1987 LV = CGF.EmitLoadOfReferenceLValue(Addr, RefTy);
1989 LV = CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
1991 setObjCGCLValueClass(CGF.getContext(), E, LV);
1995 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
1996 const Expr *E, const FunctionDecl *FD) {
1997 llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD);
1998 if (!FD->hasPrototype()) {
1999 if (const FunctionProtoType *Proto =
2000 FD->getType()->getAs<FunctionProtoType>()) {
2001 // Ugly case: for a K&R-style definition, the type of the definition
2002 // isn't the same as the type of a use. Correct for this with a
2004 QualType NoProtoType =
2005 CGF.getContext().getFunctionNoProtoType(Proto->getReturnType());
2006 NoProtoType = CGF.getContext().getPointerType(NoProtoType);
2007 V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType));
2010 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2011 return CGF.MakeAddrLValue(V, E->getType(), Alignment, AlignmentSource::Decl);
2014 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2015 llvm::Value *ThisValue) {
2016 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2017 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2018 return CGF.EmitLValueForField(LV, FD);
2021 /// Named Registers are named metadata pointing to the register name
2022 /// which will be read from/written to as an argument to the intrinsic
2023 /// @llvm.read/write_register.
2024 /// So far, only the name is being passed down, but other options such as
2025 /// register type, allocation type or even optimization options could be
2026 /// passed down via the metadata node.
2027 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2028 SmallString<64> Name("llvm.named.register.");
2029 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2030 assert(Asm->getLabel().size() < 64-Name.size() &&
2031 "Register name too big");
2032 Name.append(Asm->getLabel());
2033 llvm::NamedMDNode *M =
2034 CGM.getModule().getOrInsertNamedMetadata(Name);
2035 if (M->getNumOperands() == 0) {
2036 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2038 llvm::Metadata *Ops[] = {Str};
2039 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2042 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2045 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2046 return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2049 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2050 const NamedDecl *ND = E->getDecl();
2051 QualType T = E->getType();
2053 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2054 // Global Named registers access via intrinsics only
2055 if (VD->getStorageClass() == SC_Register &&
2056 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2057 return EmitGlobalNamedRegister(VD, CGM);
2059 // A DeclRefExpr for a reference initialized by a constant expression can
2060 // appear without being odr-used. Directly emit the constant initializer.
2061 const Expr *Init = VD->getAnyInitializer(VD);
2062 if (Init && !isa<ParmVarDecl>(VD) && VD->getType()->isReferenceType() &&
2063 VD->isUsableInConstantExpressions(getContext()) &&
2064 VD->checkInitIsICE() &&
2065 // Do not emit if it is private OpenMP variable.
2066 !(E->refersToEnclosingVariableOrCapture() && CapturedStmtInfo &&
2067 LocalDeclMap.count(VD))) {
2068 llvm::Constant *Val =
2069 CGM.EmitConstantValue(*VD->evaluateValue(), VD->getType(), this);
2070 assert(Val && "failed to emit reference constant expression");
2071 // FIXME: Eventually we will want to emit vector element references.
2073 // Should we be using the alignment of the constant pointer we emitted?
2074 CharUnits Alignment = getNaturalTypeAlignment(E->getType(), nullptr,
2077 return MakeAddrLValue(Address(Val, Alignment), T, AlignmentSource::Decl);
2080 // Check for captured variables.
2081 if (E->refersToEnclosingVariableOrCapture()) {
2082 if (auto *FD = LambdaCaptureFields.lookup(VD))
2083 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2084 else if (CapturedStmtInfo) {
2085 auto it = LocalDeclMap.find(VD);
2086 if (it != LocalDeclMap.end()) {
2087 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2088 return EmitLoadOfReferenceLValue(it->second, RefTy);
2090 return MakeAddrLValue(it->second, T);
2093 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2094 CapturedStmtInfo->getContextValue());
2095 return MakeAddrLValue(
2096 Address(CapLVal.getPointer(), getContext().getDeclAlign(VD)),
2097 CapLVal.getType(), AlignmentSource::Decl);
2100 assert(isa<BlockDecl>(CurCodeDecl));
2101 Address addr = GetAddrOfBlockDecl(VD, VD->hasAttr<BlocksAttr>());
2102 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2106 // FIXME: We should be able to assert this for FunctionDecls as well!
2107 // FIXME: We should be able to assert this for all DeclRefExprs, not just
2108 // those with a valid source location.
2109 assert((ND->isUsed(false) || !isa<VarDecl>(ND) ||
2110 !E->getLocation().isValid()) &&
2111 "Should not use decl without marking it used!");
2113 if (ND->hasAttr<WeakRefAttr>()) {
2114 const auto *VD = cast<ValueDecl>(ND);
2115 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2116 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2119 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2120 // Check if this is a global variable.
2121 if (VD->hasLinkage() || VD->isStaticDataMember())
2122 return EmitGlobalVarDeclLValue(*this, E, VD);
2124 Address addr = Address::invalid();
2126 // The variable should generally be present in the local decl map.
2127 auto iter = LocalDeclMap.find(VD);
2128 if (iter != LocalDeclMap.end()) {
2129 addr = iter->second;
2131 // Otherwise, it might be static local we haven't emitted yet for
2132 // some reason; most likely, because it's in an outer function.
2133 } else if (VD->isStaticLocal()) {
2134 addr = Address(CGM.getOrCreateStaticVarDecl(
2135 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false)),
2136 getContext().getDeclAlign(VD));
2138 // No other cases for now.
2140 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2144 // Check for OpenMP threadprivate variables.
2145 if (getLangOpts().OpenMP && VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2146 return EmitThreadPrivateVarDeclLValue(
2147 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2151 // Drill into block byref variables.
2152 bool isBlockByref = VD->hasAttr<BlocksAttr>();
2154 addr = emitBlockByrefAddress(addr, VD);
2157 // Drill into reference types.
2159 if (auto RefTy = VD->getType()->getAs<ReferenceType>()) {
2160 LV = EmitLoadOfReferenceLValue(addr, RefTy);
2162 LV = MakeAddrLValue(addr, T, AlignmentSource::Decl);
2165 bool isLocalStorage = VD->hasLocalStorage();
2167 bool NonGCable = isLocalStorage &&
2168 !VD->getType()->isReferenceType() &&
2171 LV.getQuals().removeObjCGCAttr();
2175 bool isImpreciseLifetime =
2176 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2177 if (isImpreciseLifetime)
2178 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2179 setObjCGCLValueClass(getContext(), E, LV);
2183 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2184 return EmitFunctionDeclLValue(*this, E, FD);
2186 llvm_unreachable("Unhandled DeclRefExpr");
2189 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2190 // __extension__ doesn't affect lvalue-ness.
2191 if (E->getOpcode() == UO_Extension)
2192 return EmitLValue(E->getSubExpr());
2194 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2195 switch (E->getOpcode()) {
2196 default: llvm_unreachable("Unknown unary operator lvalue!");
2198 QualType T = E->getSubExpr()->getType()->getPointeeType();
2199 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2201 AlignmentSource AlignSource;
2202 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &AlignSource);
2203 LValue LV = MakeAddrLValue(Addr, T, AlignSource);
2204 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2206 // We should not generate __weak write barrier on indirect reference
2207 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2208 // But, we continue to generate __strong write barrier on indirect write
2209 // into a pointer to object.
2210 if (getLangOpts().ObjC1 &&
2211 getLangOpts().getGC() != LangOptions::NonGC &&
2213 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2218 LValue LV = EmitLValue(E->getSubExpr());
2219 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2221 // __real is valid on scalars. This is a faster way of testing that.
2222 // __imag can only produce an rvalue on scalars.
2223 if (E->getOpcode() == UO_Real &&
2224 !LV.getAddress().getElementType()->isStructTy()) {
2225 assert(E->getSubExpr()->getType()->isArithmeticType());
2229 assert(E->getSubExpr()->getType()->isAnyComplexType());
2232 (E->getOpcode() == UO_Real
2233 ? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
2234 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
2235 return MakeAddrLValue(Component, ExprTy, LV.getAlignmentSource());
2239 LValue LV = EmitLValue(E->getSubExpr());
2240 bool isInc = E->getOpcode() == UO_PreInc;
2242 if (E->getType()->isAnyComplexType())
2243 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2245 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2251 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2252 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2253 E->getType(), AlignmentSource::Decl);
2256 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2257 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2258 E->getType(), AlignmentSource::Decl);
2261 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2262 auto SL = E->getFunctionName();
2263 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2264 StringRef FnName = CurFn->getName();
2265 if (FnName.startswith("\01"))
2266 FnName = FnName.substr(1);
2267 StringRef NameItems[] = {
2268 PredefinedExpr::getIdentTypeName(E->getIdentType()), FnName};
2269 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2270 if (CurCodeDecl && isa<BlockDecl>(CurCodeDecl)) {
2271 auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2272 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2274 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2275 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2278 /// Emit a type description suitable for use by a runtime sanitizer library. The
2279 /// format of a type descriptor is
2282 /// { i16 TypeKind, i16 TypeInfo }
2285 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2286 /// integer, 1 for a floating point value, and -1 for anything else.
2287 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2288 // Only emit each type's descriptor once.
2289 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2292 uint16_t TypeKind = -1;
2293 uint16_t TypeInfo = 0;
2295 if (T->isIntegerType()) {
2297 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2298 (T->isSignedIntegerType() ? 1 : 0);
2299 } else if (T->isFloatingType()) {
2301 TypeInfo = getContext().getTypeSize(T);
2304 // Format the type name as if for a diagnostic, including quotes and
2305 // optionally an 'aka'.
2306 SmallString<32> Buffer;
2307 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
2308 (intptr_t)T.getAsOpaquePtr(),
2309 StringRef(), StringRef(), None, Buffer,
2312 llvm::Constant *Components[] = {
2313 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2314 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2316 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2318 auto *GV = new llvm::GlobalVariable(
2319 CGM.getModule(), Descriptor->getType(),
2320 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2321 GV->setUnnamedAddr(true);
2322 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
2324 // Remember the descriptor for this type.
2325 CGM.setTypeDescriptorInMap(T, GV);
2330 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
2331 llvm::Type *TargetTy = IntPtrTy;
2333 // Floating-point types which fit into intptr_t are bitcast to integers
2334 // and then passed directly (after zero-extension, if necessary).
2335 if (V->getType()->isFloatingPointTy()) {
2336 unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2337 if (Bits <= TargetTy->getIntegerBitWidth())
2338 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2342 // Integers which fit in intptr_t are zero-extended and passed directly.
2343 if (V->getType()->isIntegerTy() &&
2344 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2345 return Builder.CreateZExt(V, TargetTy);
2347 // Pointers are passed directly, everything else is passed by address.
2348 if (!V->getType()->isPointerTy()) {
2349 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2350 Builder.CreateStore(V, Ptr);
2351 V = Ptr.getPointer();
2353 return Builder.CreatePtrToInt(V, TargetTy);
2356 /// \brief Emit a representation of a SourceLocation for passing to a handler
2357 /// in a sanitizer runtime library. The format for this data is:
2359 /// struct SourceLocation {
2360 /// const char *Filename;
2361 /// int32_t Line, Column;
2364 /// For an invalid SourceLocation, the Filename pointer is null.
2365 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
2366 llvm::Constant *Filename;
2369 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
2370 if (PLoc.isValid()) {
2371 StringRef FilenameString = PLoc.getFilename();
2373 int PathComponentsToStrip =
2374 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2375 if (PathComponentsToStrip < 0) {
2376 assert(PathComponentsToStrip != INT_MIN);
2377 int PathComponentsToKeep = -PathComponentsToStrip;
2378 auto I = llvm::sys::path::rbegin(FilenameString);
2379 auto E = llvm::sys::path::rend(FilenameString);
2380 while (I != E && --PathComponentsToKeep)
2383 FilenameString = FilenameString.substr(I - E);
2384 } else if (PathComponentsToStrip > 0) {
2385 auto I = llvm::sys::path::begin(FilenameString);
2386 auto E = llvm::sys::path::end(FilenameString);
2387 while (I != E && PathComponentsToStrip--)
2392 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2394 FilenameString = llvm::sys::path::filename(FilenameString);
2397 auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2398 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
2399 cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2400 Filename = FilenameGV.getPointer();
2401 Line = PLoc.getLine();
2402 Column = PLoc.getColumn();
2404 Filename = llvm::Constant::getNullValue(Int8PtrTy);
2408 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2409 Builder.getInt32(Column)};
2411 return llvm::ConstantStruct::getAnon(Data);
2415 /// \brief Specify under what conditions this check can be recovered
2416 enum class CheckRecoverableKind {
2417 /// Always terminate program execution if this check fails.
2419 /// Check supports recovering, runtime has both fatal (noreturn) and
2420 /// non-fatal handlers for this check.
2422 /// Runtime conditionally aborts, always need to support recovery.
2427 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
2428 assert(llvm::countPopulation(Kind) == 1);
2430 case SanitizerKind::Vptr:
2431 return CheckRecoverableKind::AlwaysRecoverable;
2432 case SanitizerKind::Return:
2433 case SanitizerKind::Unreachable:
2434 return CheckRecoverableKind::Unrecoverable;
2436 return CheckRecoverableKind::Recoverable;
2440 static void emitCheckHandlerCall(CodeGenFunction &CGF,
2441 llvm::FunctionType *FnType,
2442 ArrayRef<llvm::Value *> FnArgs,
2443 StringRef CheckName,
2444 CheckRecoverableKind RecoverKind, bool IsFatal,
2445 llvm::BasicBlock *ContBB) {
2446 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2447 bool NeedsAbortSuffix =
2448 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2449 std::string FnName = ("__ubsan_handle_" + CheckName +
2450 (NeedsAbortSuffix ? "_abort" : "")).str();
2452 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
2454 llvm::AttrBuilder B;
2456 B.addAttribute(llvm::Attribute::NoReturn)
2457 .addAttribute(llvm::Attribute::NoUnwind);
2459 B.addAttribute(llvm::Attribute::UWTable);
2461 llvm::Value *Fn = CGF.CGM.CreateRuntimeFunction(
2463 llvm::AttributeSet::get(CGF.getLLVMContext(),
2464 llvm::AttributeSet::FunctionIndex, B));
2465 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
2467 HandlerCall->setDoesNotReturn();
2468 CGF.Builder.CreateUnreachable();
2470 CGF.Builder.CreateBr(ContBB);
2474 void CodeGenFunction::EmitCheck(
2475 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
2476 StringRef CheckName, ArrayRef<llvm::Constant *> StaticArgs,
2477 ArrayRef<llvm::Value *> DynamicArgs) {
2478 assert(IsSanitizerScope);
2479 assert(Checked.size() > 0);
2481 llvm::Value *FatalCond = nullptr;
2482 llvm::Value *RecoverableCond = nullptr;
2483 llvm::Value *TrapCond = nullptr;
2484 for (int i = 0, n = Checked.size(); i < n; ++i) {
2485 llvm::Value *Check = Checked[i].first;
2486 // -fsanitize-trap= overrides -fsanitize-recover=.
2487 llvm::Value *&Cond =
2488 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
2490 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
2493 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
2497 EmitTrapCheck(TrapCond);
2498 if (!FatalCond && !RecoverableCond)
2501 llvm::Value *JointCond;
2502 if (FatalCond && RecoverableCond)
2503 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
2505 JointCond = FatalCond ? FatalCond : RecoverableCond;
2508 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
2509 assert(SanOpts.has(Checked[0].second));
2511 for (int i = 1, n = Checked.size(); i < n; ++i) {
2512 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
2513 "All recoverable kinds in a single check must be same!");
2514 assert(SanOpts.has(Checked[i].second));
2518 llvm::BasicBlock *Cont = createBasicBlock("cont");
2519 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
2520 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
2521 // Give hint that we very much don't expect to execute the handler
2522 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
2523 llvm::MDBuilder MDHelper(getLLVMContext());
2524 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2525 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
2526 EmitBlock(Handlers);
2528 // Handler functions take an i8* pointing to the (handler-specific) static
2529 // information block, followed by a sequence of intptr_t arguments
2530 // representing operand values.
2531 SmallVector<llvm::Value *, 4> Args;
2532 SmallVector<llvm::Type *, 4> ArgTypes;
2533 Args.reserve(DynamicArgs.size() + 1);
2534 ArgTypes.reserve(DynamicArgs.size() + 1);
2536 // Emit handler arguments and create handler function type.
2537 if (!StaticArgs.empty()) {
2538 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2540 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2541 llvm::GlobalVariable::PrivateLinkage, Info);
2542 InfoPtr->setUnnamedAddr(true);
2543 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2544 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
2545 ArgTypes.push_back(Int8PtrTy);
2548 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
2549 Args.push_back(EmitCheckValue(DynamicArgs[i]));
2550 ArgTypes.push_back(IntPtrTy);
2553 llvm::FunctionType *FnType =
2554 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
2556 if (!FatalCond || !RecoverableCond) {
2557 // Simple case: we need to generate a single handler call, either
2558 // fatal, or non-fatal.
2559 emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind,
2560 (FatalCond != nullptr), Cont);
2562 // Emit two handler calls: first one for set of unrecoverable checks,
2563 // another one for recoverable.
2564 llvm::BasicBlock *NonFatalHandlerBB =
2565 createBasicBlock("non_fatal." + CheckName);
2566 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
2567 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
2568 EmitBlock(FatalHandlerBB);
2569 emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind, true,
2571 EmitBlock(NonFatalHandlerBB);
2572 emitCheckHandlerCall(*this, FnType, Args, CheckName, RecoverKind, false,
2579 void CodeGenFunction::EmitCfiSlowPathCheck(
2580 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
2581 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
2582 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
2584 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
2585 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
2587 llvm::MDBuilder MDHelper(getLLVMContext());
2588 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
2589 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
2593 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
2595 llvm::CallInst *CheckCall;
2597 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
2599 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
2600 llvm::GlobalVariable::PrivateLinkage, Info);
2601 InfoPtr->setUnnamedAddr(true);
2602 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
2604 llvm::Constant *SlowPathDiagFn = CGM.getModule().getOrInsertFunction(
2605 "__cfi_slowpath_diag",
2606 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
2608 CheckCall = Builder.CreateCall(
2610 {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
2612 llvm::Constant *SlowPathFn = CGM.getModule().getOrInsertFunction(
2614 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
2615 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
2618 CheckCall->setDoesNotThrow();
2623 // This function is basically a switch over the CFI failure kind, which is
2624 // extracted from CFICheckFailData (1st function argument). Each case is either
2625 // llvm.trap or a call to one of the two runtime handlers, based on
2626 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
2627 // failure kind) traps, but this should really never happen. CFICheckFailData
2628 // can be nullptr if the calling module has -fsanitize-trap behavior for this
2629 // check kind; in this case __cfi_check_fail traps as well.
2630 void CodeGenFunction::EmitCfiCheckFail() {
2631 SanitizerScope SanScope(this);
2632 FunctionArgList Args;
2633 ImplicitParamDecl ArgData(getContext(), nullptr, SourceLocation(), nullptr,
2634 getContext().VoidPtrTy);
2635 ImplicitParamDecl ArgAddr(getContext(), nullptr, SourceLocation(), nullptr,
2636 getContext().VoidPtrTy);
2637 Args.push_back(&ArgData);
2638 Args.push_back(&ArgAddr);
2640 const CGFunctionInfo &FI =
2641 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
2643 llvm::Function *F = llvm::Function::Create(
2644 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
2645 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
2646 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
2648 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
2652 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
2653 CGM.getContext().VoidPtrTy, ArgData.getLocation());
2655 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
2656 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
2658 // Data == nullptr means the calling module has trap behaviour for this check.
2659 llvm::Value *DataIsNotNullPtr =
2660 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
2661 EmitTrapCheck(DataIsNotNullPtr);
2663 llvm::StructType *SourceLocationTy =
2664 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty, nullptr);
2665 llvm::StructType *CfiCheckFailDataTy =
2666 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy, nullptr);
2668 llvm::Value *V = Builder.CreateConstGEP2_32(
2670 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
2672 Address CheckKindAddr(V, getIntAlign());
2673 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
2675 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
2676 CGM.getLLVMContext(),
2677 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
2678 llvm::Value *ValidVtable = Builder.CreateZExt(
2679 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::bitset_test),
2680 {Addr, AllVtables}),
2683 const std::pair<int, SanitizerMask> CheckKinds[] = {
2684 {CFITCK_VCall, SanitizerKind::CFIVCall},
2685 {CFITCK_NVCall, SanitizerKind::CFINVCall},
2686 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
2687 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
2688 {CFITCK_ICall, SanitizerKind::CFIICall}};
2690 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
2691 for (auto CheckKindMaskPair : CheckKinds) {
2692 int Kind = CheckKindMaskPair.first;
2693 SanitizerMask Mask = CheckKindMaskPair.second;
2695 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
2696 if (CGM.getLangOpts().Sanitize.has(Mask))
2697 EmitCheck(std::make_pair(Cond, Mask), "cfi_check_fail", {},
2698 {Data, Addr, ValidVtable});
2700 EmitTrapCheck(Cond);
2704 // The only reference to this function will be created during LTO link.
2705 // Make sure it survives until then.
2706 CGM.addUsedGlobal(F);
2709 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
2710 llvm::BasicBlock *Cont = createBasicBlock("cont");
2712 // If we're optimizing, collapse all calls to trap down to just one per
2713 // function to save on code size.
2714 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
2715 TrapBB = createBasicBlock("trap");
2716 Builder.CreateCondBr(Checked, Cont, TrapBB);
2718 llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
2719 TrapCall->setDoesNotReturn();
2720 TrapCall->setDoesNotThrow();
2721 Builder.CreateUnreachable();
2723 Builder.CreateCondBr(Checked, Cont, TrapBB);
2729 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
2730 llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
2732 if (!CGM.getCodeGenOpts().TrapFuncName.empty())
2733 TrapCall->addAttribute(llvm::AttributeSet::FunctionIndex,
2735 CGM.getCodeGenOpts().TrapFuncName);
2740 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
2741 AlignmentSource *AlignSource) {
2742 assert(E->getType()->isArrayType() &&
2743 "Array to pointer decay must have array source type!");
2745 // Expressions of array type can't be bitfields or vector elements.
2746 LValue LV = EmitLValue(E);
2747 Address Addr = LV.getAddress();
2748 if (AlignSource) *AlignSource = LV.getAlignmentSource();
2750 // If the array type was an incomplete type, we need to make sure
2751 // the decay ends up being the right type.
2752 llvm::Type *NewTy = ConvertType(E->getType());
2753 Addr = Builder.CreateElementBitCast(Addr, NewTy);
2755 // Note that VLA pointers are always decayed, so we don't need to do
2757 if (!E->getType()->isVariableArrayType()) {
2758 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
2759 "Expected pointer to array");
2760 Addr = Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(), "arraydecay");
2763 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
2764 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
2767 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
2768 /// array to pointer, return the array subexpression.
2769 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
2770 // If this isn't just an array->pointer decay, bail out.
2771 const auto *CE = dyn_cast<CastExpr>(E);
2772 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
2775 // If this is a decay from variable width array, bail out.
2776 const Expr *SubExpr = CE->getSubExpr();
2777 if (SubExpr->getType()->isVariableArrayType())
2783 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
2785 ArrayRef<llvm::Value*> indices,
2787 const llvm::Twine &name = "arrayidx") {
2789 return CGF.Builder.CreateInBoundsGEP(ptr, indices, name);
2791 return CGF.Builder.CreateGEP(ptr, indices, name);
2795 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
2797 CharUnits eltSize) {
2798 // If we have a constant index, we can use the exact offset of the
2799 // element we're accessing.
2800 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
2801 CharUnits offset = constantIdx->getZExtValue() * eltSize;
2802 return arrayAlign.alignmentAtOffset(offset);
2804 // Otherwise, use the worst-case alignment for any element.
2806 return arrayAlign.alignmentOfArrayElement(eltSize);
2810 static QualType getFixedSizeElementType(const ASTContext &ctx,
2811 const VariableArrayType *vla) {
2814 eltType = vla->getElementType();
2815 } while ((vla = ctx.getAsVariableArrayType(eltType)));
2819 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
2820 ArrayRef<llvm::Value*> indices,
2821 QualType eltType, bool inbounds,
2822 const llvm::Twine &name = "arrayidx") {
2823 // All the indices except that last must be zero.
2825 for (auto idx : indices.drop_back())
2826 assert(isa<llvm::ConstantInt>(idx) &&
2827 cast<llvm::ConstantInt>(idx)->isZero());
2830 // Determine the element size of the statically-sized base. This is
2831 // the thing that the indices are expressed in terms of.
2832 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
2833 eltType = getFixedSizeElementType(CGF.getContext(), vla);
2836 // We can use that to compute the best alignment of the element.
2837 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
2838 CharUnits eltAlign =
2839 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
2841 llvm::Value *eltPtr =
2842 emitArraySubscriptGEP(CGF, addr.getPointer(), indices, inbounds, name);
2843 return Address(eltPtr, eltAlign);
2846 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
2848 // The index must always be an integer, which is not an aggregate. Emit it.
2849 llvm::Value *Idx = EmitScalarExpr(E->getIdx());
2850 QualType IdxTy = E->getIdx()->getType();
2851 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
2853 if (SanOpts.has(SanitizerKind::ArrayBounds))
2854 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
2856 // If the base is a vector type, then we are forming a vector element lvalue
2857 // with this subscript.
2858 if (E->getBase()->getType()->isVectorType() &&
2859 !isa<ExtVectorElementExpr>(E->getBase())) {
2860 // Emit the vector as an lvalue to get its address.
2861 LValue LHS = EmitLValue(E->getBase());
2862 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
2863 return LValue::MakeVectorElt(LHS.getAddress(), Idx,
2864 E->getBase()->getType(),
2865 LHS.getAlignmentSource());
2868 // All the other cases basically behave like simple offsetting.
2870 // Extend or truncate the index type to 32 or 64-bits.
2871 if (Idx->getType() != IntPtrTy)
2872 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
2874 // Handle the extvector case we ignored above.
2875 if (isa<ExtVectorElementExpr>(E->getBase())) {
2876 LValue LV = EmitLValue(E->getBase());
2877 Address Addr = EmitExtVectorElementLValue(LV);
2879 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
2880 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true);
2881 return MakeAddrLValue(Addr, EltType, LV.getAlignmentSource());
2884 AlignmentSource AlignSource;
2885 Address Addr = Address::invalid();
2886 if (const VariableArrayType *vla =
2887 getContext().getAsVariableArrayType(E->getType())) {
2888 // The base must be a pointer, which is not an aggregate. Emit
2889 // it. It needs to be emitted first in case it's what captures
2891 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
2893 // The element count here is the total number of non-VLA elements.
2894 llvm::Value *numElements = getVLASize(vla).first;
2896 // Effectively, the multiply by the VLA size is part of the GEP.
2897 // GEP indexes are signed, and scaling an index isn't permitted to
2898 // signed-overflow, so we use the same semantics for our explicit
2899 // multiply. We suppress this if overflow is not undefined behavior.
2900 if (getLangOpts().isSignedOverflowDefined()) {
2901 Idx = Builder.CreateMul(Idx, numElements);
2903 Idx = Builder.CreateNSWMul(Idx, numElements);
2906 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
2907 !getLangOpts().isSignedOverflowDefined());
2909 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
2910 // Indexing over an interface, as in "NSString *P; P[4];"
2911 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
2912 llvm::Value *InterfaceSizeVal =
2913 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());;
2915 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
2917 // Emit the base pointer.
2918 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
2920 // We don't necessarily build correct LLVM struct types for ObjC
2921 // interfaces, so we can't rely on GEP to do this scaling
2922 // correctly, so we need to cast to i8*. FIXME: is this actually
2923 // true? A lot of other things in the fragile ABI would break...
2924 llvm::Type *OrigBaseTy = Addr.getType();
2925 Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
2928 CharUnits EltAlign =
2929 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
2930 llvm::Value *EltPtr =
2931 emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false);
2932 Addr = Address(EltPtr, EltAlign);
2935 Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
2936 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
2937 // If this is A[i] where A is an array, the frontend will have decayed the
2938 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
2939 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
2940 // "gep x, i" here. Emit one "gep A, 0, i".
2941 assert(Array->getType()->isArrayType() &&
2942 "Array to pointer decay must have array source type!");
2944 // For simple multidimensional array indexing, set the 'accessed' flag for
2945 // better bounds-checking of the base expression.
2946 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
2947 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
2949 ArrayLV = EmitLValue(Array);
2951 // Propagate the alignment from the array itself to the result.
2952 Addr = emitArraySubscriptGEP(*this, ArrayLV.getAddress(),
2953 {CGM.getSize(CharUnits::Zero()), Idx},
2955 !getLangOpts().isSignedOverflowDefined());
2956 AlignSource = ArrayLV.getAlignmentSource();
2958 // The base must be a pointer; emit it with an estimate of its alignment.
2959 Addr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
2960 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
2961 !getLangOpts().isSignedOverflowDefined());
2964 LValue LV = MakeAddrLValue(Addr, E->getType(), AlignSource);
2966 // TODO: Preserve/extend path TBAA metadata?
2968 if (getLangOpts().ObjC1 &&
2969 getLangOpts().getGC() != LangOptions::NonGC) {
2970 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2971 setObjCGCLValueClass(getContext(), E, LV);
2976 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
2977 AlignmentSource &AlignSource,
2978 QualType BaseTy, QualType ElTy,
2979 bool IsLowerBound) {
2981 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
2982 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
2983 if (BaseTy->isArrayType()) {
2984 Address Addr = BaseLVal.getAddress();
2985 AlignSource = BaseLVal.getAlignmentSource();
2987 // If the array type was an incomplete type, we need to make sure
2988 // the decay ends up being the right type.
2989 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
2990 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
2992 // Note that VLA pointers are always decayed, so we don't need to do
2994 if (!BaseTy->isVariableArrayType()) {
2995 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
2996 "Expected pointer to array");
2997 Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
3001 return CGF.Builder.CreateElementBitCast(Addr,
3002 CGF.ConvertTypeForMem(ElTy));
3004 CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &AlignSource);
3005 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
3007 return CGF.EmitPointerWithAlignment(Base, &AlignSource);
3010 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3011 bool IsLowerBound) {
3014 dyn_cast<OMPArraySectionExpr>(E->getBase()->IgnoreParenImpCasts()))
3015 BaseTy = OMPArraySectionExpr::getBaseOriginalType(ASE);
3017 BaseTy = E->getBase()->getType();
3018 QualType ResultExprTy;
3019 if (auto *AT = getContext().getAsArrayType(BaseTy))
3020 ResultExprTy = AT->getElementType();
3022 ResultExprTy = BaseTy->getPointeeType();
3023 llvm::Value *Idx = nullptr;
3024 if (IsLowerBound || E->getColonLoc().isInvalid()) {
3025 // Requesting lower bound or upper bound, but without provided length and
3026 // without ':' symbol for the default length -> length = 1.
3027 // Idx = LowerBound ?: 0;
3028 if (auto *LowerBound = E->getLowerBound()) {
3029 Idx = Builder.CreateIntCast(
3030 EmitScalarExpr(LowerBound), IntPtrTy,
3031 LowerBound->getType()->hasSignedIntegerRepresentation());
3033 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3035 // Try to emit length or lower bound as constant. If this is possible, 1
3036 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3037 // IR (LB + Len) - 1.
3038 auto &C = CGM.getContext();
3039 auto *Length = E->getLength();
3040 llvm::APSInt ConstLength;
3042 // Idx = LowerBound + Length - 1;
3043 if (Length->isIntegerConstantExpr(ConstLength, C)) {
3044 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3047 auto *LowerBound = E->getLowerBound();
3048 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3049 if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3050 ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3051 LowerBound = nullptr;
3055 else if (!LowerBound)
3058 if (Length || LowerBound) {
3059 auto *LowerBoundVal =
3061 ? Builder.CreateIntCast(
3062 EmitScalarExpr(LowerBound), IntPtrTy,
3063 LowerBound->getType()->hasSignedIntegerRepresentation())
3064 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3067 ? Builder.CreateIntCast(
3068 EmitScalarExpr(Length), IntPtrTy,
3069 Length->getType()->hasSignedIntegerRepresentation())
3070 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3071 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3073 !getLangOpts().isSignedOverflowDefined());
3074 if (Length && LowerBound) {
3075 Idx = Builder.CreateSub(
3076 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3077 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3080 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3082 // Idx = ArraySize - 1;
3083 QualType ArrayTy = BaseTy->isPointerType()
3084 ? E->getBase()->IgnoreParenImpCasts()->getType()
3086 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3087 Length = VAT->getSizeExpr();
3088 if (Length->isIntegerConstantExpr(ConstLength, C))
3091 auto *CAT = C.getAsConstantArrayType(ArrayTy);
3092 ConstLength = CAT->getSize();
3095 auto *LengthVal = Builder.CreateIntCast(
3096 EmitScalarExpr(Length), IntPtrTy,
3097 Length->getType()->hasSignedIntegerRepresentation());
3098 Idx = Builder.CreateSub(
3099 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3100 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3102 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3104 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3110 Address EltPtr = Address::invalid();
3111 AlignmentSource AlignSource;
3112 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3113 // The base must be a pointer, which is not an aggregate. Emit
3114 // it. It needs to be emitted first in case it's what captures
3117 emitOMPArraySectionBase(*this, E->getBase(), AlignSource, BaseTy,
3118 VLA->getElementType(), IsLowerBound);
3119 // The element count here is the total number of non-VLA elements.
3120 llvm::Value *NumElements = getVLASize(VLA).first;
3122 // Effectively, the multiply by the VLA size is part of the GEP.
3123 // GEP indexes are signed, and scaling an index isn't permitted to
3124 // signed-overflow, so we use the same semantics for our explicit
3125 // multiply. We suppress this if overflow is not undefined behavior.
3126 if (getLangOpts().isSignedOverflowDefined())
3127 Idx = Builder.CreateMul(Idx, NumElements);
3129 Idx = Builder.CreateNSWMul(Idx, NumElements);
3130 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3131 !getLangOpts().isSignedOverflowDefined());
3132 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3133 // If this is A[i] where A is an array, the frontend will have decayed the
3134 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3135 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3136 // "gep x, i" here. Emit one "gep A, 0, i".
3137 assert(Array->getType()->isArrayType() &&
3138 "Array to pointer decay must have array source type!");
3140 // For simple multidimensional array indexing, set the 'accessed' flag for
3141 // better bounds-checking of the base expression.
3142 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3143 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3145 ArrayLV = EmitLValue(Array);
3147 // Propagate the alignment from the array itself to the result.
3148 EltPtr = emitArraySubscriptGEP(
3149 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
3150 ResultExprTy, !getLangOpts().isSignedOverflowDefined());
3151 AlignSource = ArrayLV.getAlignmentSource();
3153 Address Base = emitOMPArraySectionBase(*this, E->getBase(), AlignSource,
3154 BaseTy, ResultExprTy, IsLowerBound);
3155 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3156 !getLangOpts().isSignedOverflowDefined());
3159 return MakeAddrLValue(EltPtr, ResultExprTy, AlignSource);
3162 LValue CodeGenFunction::
3163 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
3164 // Emit the base vector as an l-value.
3167 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3169 // If it is a pointer to a vector, emit the address and form an lvalue with
3171 AlignmentSource AlignSource;
3172 Address Ptr = EmitPointerWithAlignment(E->getBase(), &AlignSource);
3173 const PointerType *PT = E->getBase()->getType()->getAs<PointerType>();
3174 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), AlignSource);
3175 Base.getQuals().removeObjCGCAttr();
3176 } else if (E->getBase()->isGLValue()) {
3177 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3178 // emit the base as an lvalue.
3179 assert(E->getBase()->getType()->isVectorType());
3180 Base = EmitLValue(E->getBase());
3182 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3183 assert(E->getBase()->getType()->isVectorType() &&
3184 "Result must be a vector");
3185 llvm::Value *Vec = EmitScalarExpr(E->getBase());
3187 // Store the vector to memory (because LValue wants an address).
3188 Address VecMem = CreateMemTemp(E->getBase()->getType());
3189 Builder.CreateStore(Vec, VecMem);
3190 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3191 AlignmentSource::Decl);
3195 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
3197 // Encode the element access list into a vector of unsigned indices.
3198 SmallVector<uint32_t, 4> Indices;
3199 E->getEncodedElementAccess(Indices);
3201 if (Base.isSimple()) {
3202 llvm::Constant *CV =
3203 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3204 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
3205 Base.getAlignmentSource());
3207 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3209 llvm::Constant *BaseElts = Base.getExtVectorElts();
3210 SmallVector<llvm::Constant *, 4> CElts;
3212 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3213 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3214 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3215 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
3216 Base.getAlignmentSource());
3219 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
3220 Expr *BaseExpr = E->getBase();
3222 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3225 AlignmentSource AlignSource;
3226 Address Addr = EmitPointerWithAlignment(BaseExpr, &AlignSource);
3227 QualType PtrTy = BaseExpr->getType()->getPointeeType();
3228 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy);
3229 BaseLV = MakeAddrLValue(Addr, PtrTy, AlignSource);
3231 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3233 NamedDecl *ND = E->getMemberDecl();
3234 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3235 LValue LV = EmitLValueForField(BaseLV, Field);
3236 setObjCGCLValueClass(getContext(), E, LV);
3240 if (auto *VD = dyn_cast<VarDecl>(ND))
3241 return EmitGlobalVarDeclLValue(*this, E, VD);
3243 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3244 return EmitFunctionDeclLValue(*this, E, FD);
3246 llvm_unreachable("Unhandled member declaration!");
3249 /// Given that we are currently emitting a lambda, emit an l-value for
3250 /// one of its members.
3251 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
3252 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3253 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3254 QualType LambdaTagType =
3255 getContext().getTagDeclType(Field->getParent());
3256 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3257 return EmitLValueForField(LambdaLV, Field);
3260 /// Drill down to the storage of a field without walking into
3261 /// reference types.
3263 /// The resulting address doesn't necessarily have the right type.
3264 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
3265 const FieldDecl *field) {
3266 const RecordDecl *rec = field->getParent();
3269 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
3272 // Adjust the alignment down to the given offset.
3273 // As a special case, if the LLVM field index is 0, we know that this
3275 assert((idx != 0 || CGF.getContext().getASTRecordLayout(rec)
3276 .getFieldOffset(field->getFieldIndex()) == 0) &&
3277 "LLVM field at index zero had non-zero offset?");
3279 auto &recLayout = CGF.getContext().getASTRecordLayout(rec);
3280 auto offsetInBits = recLayout.getFieldOffset(field->getFieldIndex());
3281 offset = CGF.getContext().toCharUnitsFromBits(offsetInBits);
3284 return CGF.Builder.CreateStructGEP(base, idx, offset, field->getName());
3287 LValue CodeGenFunction::EmitLValueForField(LValue base,
3288 const FieldDecl *field) {
3289 AlignmentSource fieldAlignSource =
3290 getFieldAlignmentSource(base.getAlignmentSource());
3292 if (field->isBitField()) {
3293 const CGRecordLayout &RL =
3294 CGM.getTypes().getCGRecordLayout(field->getParent());
3295 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
3296 Address Addr = base.getAddress();
3297 unsigned Idx = RL.getLLVMFieldNo(field);
3299 // For structs, we GEP to the field that the record layout suggests.
3300 Addr = Builder.CreateStructGEP(Addr, Idx, Info.StorageOffset,
3302 // Get the access type.
3303 llvm::Type *FieldIntTy =
3304 llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
3305 if (Addr.getElementType() != FieldIntTy)
3306 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
3308 QualType fieldType =
3309 field->getType().withCVRQualifiers(base.getVRQualifiers());
3310 return LValue::MakeBitfield(Addr, Info, fieldType, fieldAlignSource);
3313 const RecordDecl *rec = field->getParent();
3314 QualType type = field->getType();
3316 bool mayAlias = rec->hasAttr<MayAliasAttr>();
3318 Address addr = base.getAddress();
3319 unsigned cvr = base.getVRQualifiers();
3320 bool TBAAPath = CGM.getCodeGenOpts().StructPathTBAA;
3321 if (rec->isUnion()) {
3322 // For unions, there is no pointer adjustment.
3323 assert(!type->isReferenceType() && "union has reference member");
3324 // TODO: handle path-aware TBAA for union.
3327 // For structs, we GEP to the field that the record layout suggests.
3328 addr = emitAddrOfFieldStorage(*this, addr, field);
3330 // If this is a reference field, load the reference right now.
3331 if (const ReferenceType *refType = type->getAs<ReferenceType>()) {
3332 llvm::LoadInst *load = Builder.CreateLoad(addr, "ref");
3333 if (cvr & Qualifiers::Volatile) load->setVolatile(true);
3335 // Loading the reference will disable path-aware TBAA.
3337 if (CGM.shouldUseTBAA()) {
3340 tbaa = CGM.getTBAAInfo(getContext().CharTy);
3342 tbaa = CGM.getTBAAInfo(type);
3344 CGM.DecorateInstructionWithTBAA(load, tbaa);
3348 type = refType->getPointeeType();
3350 CharUnits alignment =
3351 getNaturalTypeAlignment(type, &fieldAlignSource, /*pointee*/ true);
3352 addr = Address(load, alignment);
3354 // Qualifiers on the struct don't apply to the referencee, and
3355 // we'll pick up CVR from the actual type later, so reset these
3356 // additional qualifiers now.
3361 // Make sure that the address is pointing to the right type. This is critical
3362 // for both unions and structs. A union needs a bitcast, a struct element
3363 // will need a bitcast if the LLVM type laid out doesn't match the desired
3365 addr = Builder.CreateElementBitCast(addr,
3366 CGM.getTypes().ConvertTypeForMem(type),
3369 if (field->hasAttr<AnnotateAttr>())
3370 addr = EmitFieldAnnotations(field, addr);
3372 LValue LV = MakeAddrLValue(addr, type, fieldAlignSource);
3373 LV.getQuals().addCVRQualifiers(cvr);
3375 const ASTRecordLayout &Layout =
3376 getContext().getASTRecordLayout(field->getParent());
3377 // Set the base type to be the base type of the base LValue and
3378 // update offset to be relative to the base type.
3379 LV.setTBAABaseType(mayAlias ? getContext().CharTy : base.getTBAABaseType());
3380 LV.setTBAAOffset(mayAlias ? 0 : base.getTBAAOffset() +
3381 Layout.getFieldOffset(field->getFieldIndex()) /
3382 getContext().getCharWidth());
3385 // __weak attribute on a field is ignored.
3386 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
3387 LV.getQuals().removeObjCGCAttr();
3389 // Fields of may_alias structs act like 'char' for TBAA purposes.
3390 // FIXME: this should get propagated down through anonymous structs
3392 if (mayAlias && LV.getTBAAInfo())
3393 LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy));
3399 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
3400 const FieldDecl *Field) {
3401 QualType FieldType = Field->getType();
3403 if (!FieldType->isReferenceType())
3404 return EmitLValueForField(Base, Field);
3406 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(), Field);
3408 // Make sure that the address is pointing to the right type.
3409 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
3410 V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
3412 // TODO: access-path TBAA?
3413 auto FieldAlignSource = getFieldAlignmentSource(Base.getAlignmentSource());
3414 return MakeAddrLValue(V, FieldType, FieldAlignSource);
3417 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
3418 if (E->isFileScope()) {
3419 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
3420 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
3422 if (E->getType()->isVariablyModifiedType())
3423 // make sure to emit the VLA size.
3424 EmitVariablyModifiedType(E->getType());
3426 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
3427 const Expr *InitExpr = E->getInitializer();
3428 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
3430 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
3436 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
3437 if (!E->isGLValue())
3438 // Initializing an aggregate temporary in C++11: T{...}.
3439 return EmitAggExprToLValue(E);
3441 // An lvalue initializer list must be initializing a reference.
3442 assert(E->getNumInits() == 1 && "reference init with multiple values");
3443 return EmitLValue(E->getInit(0));
3446 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
3447 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
3448 /// LValue is returned and the current block has been terminated.
3449 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
3450 const Expr *Operand) {
3451 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
3452 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
3456 return CGF.EmitLValue(Operand);
3459 LValue CodeGenFunction::
3460 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
3461 if (!expr->isGLValue()) {
3462 // ?: here should be an aggregate.
3463 assert(hasAggregateEvaluationKind(expr->getType()) &&
3464 "Unexpected conditional operator!");
3465 return EmitAggExprToLValue(expr);
3468 OpaqueValueMapping binding(*this, expr);
3470 const Expr *condExpr = expr->getCond();
3472 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
3473 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
3474 if (!CondExprBool) std::swap(live, dead);
3476 if (!ContainsLabel(dead)) {
3477 // If the true case is live, we need to track its region.
3479 incrementProfileCounter(expr);
3480 return EmitLValue(live);
3484 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
3485 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
3486 llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
3488 ConditionalEvaluation eval(*this);
3489 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
3491 // Any temporaries created here are conditional.
3492 EmitBlock(lhsBlock);
3493 incrementProfileCounter(expr);
3495 Optional<LValue> lhs =
3496 EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
3499 if (lhs && !lhs->isSimple())
3500 return EmitUnsupportedLValue(expr, "conditional operator");
3502 lhsBlock = Builder.GetInsertBlock();
3504 Builder.CreateBr(contBlock);
3506 // Any temporaries created here are conditional.
3507 EmitBlock(rhsBlock);
3509 Optional<LValue> rhs =
3510 EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
3512 if (rhs && !rhs->isSimple())
3513 return EmitUnsupportedLValue(expr, "conditional operator");
3514 rhsBlock = Builder.GetInsertBlock();
3516 EmitBlock(contBlock);
3519 llvm::PHINode *phi = Builder.CreatePHI(lhs->getPointer()->getType(),
3521 phi->addIncoming(lhs->getPointer(), lhsBlock);
3522 phi->addIncoming(rhs->getPointer(), rhsBlock);
3523 Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
3524 AlignmentSource alignSource =
3525 std::max(lhs->getAlignmentSource(), rhs->getAlignmentSource());
3526 return MakeAddrLValue(result, expr->getType(), alignSource);
3528 assert((lhs || rhs) &&
3529 "both operands of glvalue conditional are throw-expressions?");
3530 return lhs ? *lhs : *rhs;
3534 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
3535 /// type. If the cast is to a reference, we can have the usual lvalue result,
3536 /// otherwise if a cast is needed by the code generator in an lvalue context,
3537 /// then it must mean that we need the address of an aggregate in order to
3538 /// access one of its members. This can happen for all the reasons that casts
3539 /// are permitted with aggregate result, including noop aggregate casts, and
3540 /// cast from scalar to union.
3541 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
3542 switch (E->getCastKind()) {
3545 case CK_ArrayToPointerDecay:
3546 case CK_FunctionToPointerDecay:
3547 case CK_NullToMemberPointer:
3548 case CK_NullToPointer:
3549 case CK_IntegralToPointer:
3550 case CK_PointerToIntegral:
3551 case CK_PointerToBoolean:
3552 case CK_VectorSplat:
3553 case CK_IntegralCast:
3554 case CK_BooleanToSignedIntegral:
3555 case CK_IntegralToBoolean:
3556 case CK_IntegralToFloating:
3557 case CK_FloatingToIntegral:
3558 case CK_FloatingToBoolean:
3559 case CK_FloatingCast:
3560 case CK_FloatingRealToComplex:
3561 case CK_FloatingComplexToReal:
3562 case CK_FloatingComplexToBoolean:
3563 case CK_FloatingComplexCast:
3564 case CK_FloatingComplexToIntegralComplex:
3565 case CK_IntegralRealToComplex:
3566 case CK_IntegralComplexToReal:
3567 case CK_IntegralComplexToBoolean:
3568 case CK_IntegralComplexCast:
3569 case CK_IntegralComplexToFloatingComplex:
3570 case CK_DerivedToBaseMemberPointer:
3571 case CK_BaseToDerivedMemberPointer:
3572 case CK_MemberPointerToBoolean:
3573 case CK_ReinterpretMemberPointer:
3574 case CK_AnyPointerToBlockPointerCast:
3575 case CK_ARCProduceObject:
3576 case CK_ARCConsumeObject:
3577 case CK_ARCReclaimReturnedObject:
3578 case CK_ARCExtendBlockObject:
3579 case CK_CopyAndAutoreleaseBlockObject:
3580 case CK_AddressSpaceConversion:
3581 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
3584 llvm_unreachable("dependent cast kind in IR gen!");
3586 case CK_BuiltinFnToFnPtr:
3587 llvm_unreachable("builtin functions are handled elsewhere");
3589 // These are never l-values; just use the aggregate emission code.
3590 case CK_NonAtomicToAtomic:
3591 case CK_AtomicToNonAtomic:
3592 return EmitAggExprToLValue(E);
3595 LValue LV = EmitLValue(E->getSubExpr());
3596 Address V = LV.getAddress();
3597 const auto *DCE = cast<CXXDynamicCastExpr>(E);
3598 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
3601 case CK_ConstructorConversion:
3602 case CK_UserDefinedConversion:
3603 case CK_CPointerToObjCPointerCast:
3604 case CK_BlockPointerToObjCPointerCast:
3606 case CK_LValueToRValue:
3607 return EmitLValue(E->getSubExpr());
3609 case CK_UncheckedDerivedToBase:
3610 case CK_DerivedToBase: {
3611 const RecordType *DerivedClassTy =
3612 E->getSubExpr()->getType()->getAs<RecordType>();
3613 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3615 LValue LV = EmitLValue(E->getSubExpr());
3616 Address This = LV.getAddress();
3618 // Perform the derived-to-base conversion
3619 Address Base = GetAddressOfBaseClass(
3620 This, DerivedClassDecl, E->path_begin(), E->path_end(),
3621 /*NullCheckValue=*/false, E->getExprLoc());
3623 return MakeAddrLValue(Base, E->getType(), LV.getAlignmentSource());
3626 return EmitAggExprToLValue(E);
3627 case CK_BaseToDerived: {
3628 const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>();
3629 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
3631 LValue LV = EmitLValue(E->getSubExpr());
3633 // Perform the base-to-derived conversion
3635 GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl,
3636 E->path_begin(), E->path_end(),
3637 /*NullCheckValue=*/false);
3639 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
3640 // performed and the object is not of the derived type.
3641 if (sanitizePerformTypeCheck())
3642 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
3643 Derived.getPointer(), E->getType());
3645 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
3646 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
3647 /*MayBeNull=*/false,
3648 CFITCK_DerivedCast, E->getLocStart());
3650 return MakeAddrLValue(Derived, E->getType(), LV.getAlignmentSource());
3652 case CK_LValueBitCast: {
3653 // This must be a reinterpret_cast (or c-style equivalent).
3654 const auto *CE = cast<ExplicitCastExpr>(E);
3656 CGM.EmitExplicitCastExprType(CE, this);
3657 LValue LV = EmitLValue(E->getSubExpr());
3658 Address V = Builder.CreateBitCast(LV.getAddress(),
3659 ConvertType(CE->getTypeAsWritten()));
3661 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
3662 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
3663 /*MayBeNull=*/false,
3664 CFITCK_UnrelatedCast, E->getLocStart());
3666 return MakeAddrLValue(V, E->getType(), LV.getAlignmentSource());
3668 case CK_ObjCObjectLValueCast: {
3669 LValue LV = EmitLValue(E->getSubExpr());
3670 Address V = Builder.CreateElementBitCast(LV.getAddress(),
3671 ConvertType(E->getType()));
3672 return MakeAddrLValue(V, E->getType(), LV.getAlignmentSource());
3674 case CK_ZeroToOCLEvent:
3675 llvm_unreachable("NULL to OpenCL event lvalue cast is not valid");
3678 llvm_unreachable("Unhandled lvalue cast kind?");
3681 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
3682 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
3683 return getOpaqueLValueMapping(e);
3686 RValue CodeGenFunction::EmitRValueForField(LValue LV,
3687 const FieldDecl *FD,
3688 SourceLocation Loc) {
3689 QualType FT = FD->getType();
3690 LValue FieldLV = EmitLValueForField(LV, FD);
3691 switch (getEvaluationKind(FT)) {
3693 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
3695 return FieldLV.asAggregateRValue();
3697 // This routine is used to load fields one-by-one to perform a copy, so
3698 // don't load reference fields.
3699 if (FD->getType()->isReferenceType())
3700 return RValue::get(FieldLV.getPointer());
3701 return EmitLoadOfLValue(FieldLV, Loc);
3703 llvm_unreachable("bad evaluation kind");
3706 //===--------------------------------------------------------------------===//
3707 // Expression Emission
3708 //===--------------------------------------------------------------------===//
3710 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
3711 ReturnValueSlot ReturnValue) {
3712 // Builtins never have block type.
3713 if (E->getCallee()->getType()->isBlockPointerType())
3714 return EmitBlockCallExpr(E, ReturnValue);
3716 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
3717 return EmitCXXMemberCallExpr(CE, ReturnValue);
3719 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
3720 return EmitCUDAKernelCallExpr(CE, ReturnValue);
3722 const Decl *TargetDecl = E->getCalleeDecl();
3723 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl)) {
3724 if (unsigned builtinID = FD->getBuiltinID())
3725 return EmitBuiltinExpr(FD, builtinID, E, ReturnValue);
3728 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
3729 if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl))
3730 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
3732 if (const auto *PseudoDtor =
3733 dyn_cast<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) {
3734 QualType DestroyedType = PseudoDtor->getDestroyedType();
3735 if (DestroyedType.hasStrongOrWeakObjCLifetime()) {
3736 // Automatic Reference Counting:
3737 // If the pseudo-expression names a retainable object with weak or
3738 // strong lifetime, the object shall be released.
3739 Expr *BaseExpr = PseudoDtor->getBase();
3740 Address BaseValue = Address::invalid();
3741 Qualifiers BaseQuals;
3743 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3744 if (PseudoDtor->isArrow()) {
3745 BaseValue = EmitPointerWithAlignment(BaseExpr);
3746 const PointerType *PTy = BaseExpr->getType()->getAs<PointerType>();
3747 BaseQuals = PTy->getPointeeType().getQualifiers();
3749 LValue BaseLV = EmitLValue(BaseExpr);
3750 BaseValue = BaseLV.getAddress();
3751 QualType BaseTy = BaseExpr->getType();
3752 BaseQuals = BaseTy.getQualifiers();
3755 switch (DestroyedType.getObjCLifetime()) {
3756 case Qualifiers::OCL_None:
3757 case Qualifiers::OCL_ExplicitNone:
3758 case Qualifiers::OCL_Autoreleasing:
3761 case Qualifiers::OCL_Strong:
3762 EmitARCRelease(Builder.CreateLoad(BaseValue,
3763 PseudoDtor->getDestroyedType().isVolatileQualified()),
3764 ARCPreciseLifetime);
3767 case Qualifiers::OCL_Weak:
3768 EmitARCDestroyWeak(BaseValue);
3772 // C++ [expr.pseudo]p1:
3773 // The result shall only be used as the operand for the function call
3774 // operator (), and the result of such a call has type void. The only
3775 // effect is the evaluation of the postfix-expression before the dot or
3777 EmitScalarExpr(E->getCallee());
3780 return RValue::get(nullptr);
3783 llvm::Value *Callee = EmitScalarExpr(E->getCallee());
3784 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue,
3788 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
3789 // Comma expressions just emit their LHS then their RHS as an l-value.
3790 if (E->getOpcode() == BO_Comma) {
3791 EmitIgnoredExpr(E->getLHS());
3792 EnsureInsertPoint();
3793 return EmitLValue(E->getRHS());
3796 if (E->getOpcode() == BO_PtrMemD ||
3797 E->getOpcode() == BO_PtrMemI)
3798 return EmitPointerToDataMemberBinaryExpr(E);
3800 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
3802 // Note that in all of these cases, __block variables need the RHS
3803 // evaluated first just in case the variable gets moved by the RHS.
3805 switch (getEvaluationKind(E->getType())) {
3807 switch (E->getLHS()->getType().getObjCLifetime()) {
3808 case Qualifiers::OCL_Strong:
3809 return EmitARCStoreStrong(E, /*ignored*/ false).first;
3811 case Qualifiers::OCL_Autoreleasing:
3812 return EmitARCStoreAutoreleasing(E).first;
3814 // No reason to do any of these differently.
3815 case Qualifiers::OCL_None:
3816 case Qualifiers::OCL_ExplicitNone:
3817 case Qualifiers::OCL_Weak:
3821 RValue RV = EmitAnyExpr(E->getRHS());
3822 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
3823 EmitStoreThroughLValue(RV, LV);
3828 return EmitComplexAssignmentLValue(E);
3831 return EmitAggExprToLValue(E);
3833 llvm_unreachable("bad evaluation kind");
3836 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
3837 RValue RV = EmitCallExpr(E);
3840 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
3841 AlignmentSource::Decl);
3843 assert(E->getCallReturnType(getContext())->isReferenceType() &&
3844 "Can't have a scalar return unless the return type is a "
3847 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
3850 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
3851 // FIXME: This shouldn't require another copy.
3852 return EmitAggExprToLValue(E);
3855 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
3856 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
3857 && "binding l-value to type which needs a temporary");
3858 AggValueSlot Slot = CreateAggTemp(E->getType());
3859 EmitCXXConstructExpr(E, Slot);
3860 return MakeAddrLValue(Slot.getAddress(), E->getType(),
3861 AlignmentSource::Decl);
3865 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
3866 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
3869 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
3870 return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
3871 ConvertType(E->getType()));
3874 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
3875 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
3876 AlignmentSource::Decl);
3880 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
3881 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
3882 Slot.setExternallyDestructed();
3883 EmitAggExpr(E->getSubExpr(), Slot);
3884 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
3885 return MakeAddrLValue(Slot.getAddress(), E->getType(),
3886 AlignmentSource::Decl);
3890 CodeGenFunction::EmitLambdaLValue(const LambdaExpr *E) {
3891 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
3892 EmitLambdaExpr(E, Slot);
3893 return MakeAddrLValue(Slot.getAddress(), E->getType(),
3894 AlignmentSource::Decl);
3897 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
3898 RValue RV = EmitObjCMessageExpr(E);
3901 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
3902 AlignmentSource::Decl);
3904 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
3905 "Can't have a scalar return unless the return type is a "
3908 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
3911 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
3913 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
3914 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
3917 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
3918 const ObjCIvarDecl *Ivar) {
3919 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
3922 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
3923 llvm::Value *BaseValue,
3924 const ObjCIvarDecl *Ivar,
3925 unsigned CVRQualifiers) {
3926 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
3927 Ivar, CVRQualifiers);
3930 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
3931 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
3932 llvm::Value *BaseValue = nullptr;
3933 const Expr *BaseExpr = E->getBase();
3934 Qualifiers BaseQuals;
3937 BaseValue = EmitScalarExpr(BaseExpr);
3938 ObjectTy = BaseExpr->getType()->getPointeeType();
3939 BaseQuals = ObjectTy.getQualifiers();
3941 LValue BaseLV = EmitLValue(BaseExpr);
3942 BaseValue = BaseLV.getPointer();
3943 ObjectTy = BaseExpr->getType();
3944 BaseQuals = ObjectTy.getQualifiers();
3948 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
3949 BaseQuals.getCVRQualifiers());
3950 setObjCGCLValueClass(getContext(), E, LV);
3954 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
3955 // Can only get l-value for message expression returning aggregate type
3956 RValue RV = EmitAnyExprToTemp(E);
3957 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
3958 AlignmentSource::Decl);
3961 RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee,
3962 const CallExpr *E, ReturnValueSlot ReturnValue,
3963 CGCalleeInfo CalleeInfo, llvm::Value *Chain) {
3964 // Get the actual function type. The callee type will always be a pointer to
3965 // function type or a block pointer type.
3966 assert(CalleeType->isFunctionPointerType() &&
3967 "Call must have function pointer type!");
3969 // Preserve the non-canonical function type because things like exception
3970 // specifications disappear in the canonical type. That information is useful
3971 // to drive the generation of more accurate code for this call later on.
3972 const FunctionProtoType *NonCanonicalFTP = CalleeType->getAs<PointerType>()
3974 ->getAs<FunctionProtoType>();
3976 const Decl *TargetDecl = CalleeInfo.getCalleeDecl();
3978 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl))
3979 // We can only guarantee that a function is called from the correct
3980 // context/function based on the appropriate target attributes,
3981 // so only check in the case where we have both always_inline and target
3982 // since otherwise we could be making a conditional call after a check for
3983 // the proper cpu features (and it won't cause code generation issues due to
3984 // function based code generation).
3985 if (TargetDecl->hasAttr<AlwaysInlineAttr>() &&
3986 TargetDecl->hasAttr<TargetAttr>())
3987 checkTargetFeatures(E, FD);
3989 CalleeType = getContext().getCanonicalType(CalleeType);
3991 const auto *FnType =
3992 cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType());
3994 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
3995 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
3996 if (llvm::Constant *PrefixSig =
3997 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
3998 SanitizerScope SanScope(this);
3999 llvm::Constant *FTRTTIConst =
4000 CGM.GetAddrOfRTTIDescriptor(QualType(FnType, 0), /*ForEH=*/true);
4001 llvm::Type *PrefixStructTyElems[] = {
4002 PrefixSig->getType(),
4003 FTRTTIConst->getType()
4005 llvm::StructType *PrefixStructTy = llvm::StructType::get(
4006 CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4008 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4009 Callee, llvm::PointerType::getUnqual(PrefixStructTy));
4010 llvm::Value *CalleeSigPtr =
4011 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4012 llvm::Value *CalleeSig =
4013 Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4014 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4016 llvm::BasicBlock *Cont = createBasicBlock("cont");
4017 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4018 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4020 EmitBlock(TypeCheck);
4021 llvm::Value *CalleeRTTIPtr =
4022 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4023 llvm::Value *CalleeRTTI =
4024 Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4025 llvm::Value *CalleeRTTIMatch =
4026 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4027 llvm::Constant *StaticData[] = {
4028 EmitCheckSourceLocation(E->getLocStart()),
4029 EmitCheckTypeDescriptor(CalleeType)
4031 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4032 "function_type_mismatch", StaticData, Callee);
4034 Builder.CreateBr(Cont);
4039 // If we are checking indirect calls and this call is indirect, check that the
4040 // function pointer is a member of the bit set for the function type.
4041 if (SanOpts.has(SanitizerKind::CFIICall) &&
4042 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4043 SanitizerScope SanScope(this);
4044 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4046 llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4047 llvm::Value *BitSetName = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4049 llvm::Value *CastedCallee = Builder.CreateBitCast(Callee, Int8PtrTy);
4050 llvm::Value *BitSetTest =
4051 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::bitset_test),
4052 {CastedCallee, BitSetName});
4054 auto TypeId = CGM.CreateCfiIdForTypeMetadata(MD);
4055 llvm::Constant *StaticData[] = {
4056 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4057 EmitCheckSourceLocation(E->getLocStart()),
4058 EmitCheckTypeDescriptor(QualType(FnType, 0)),
4060 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && TypeId) {
4061 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, BitSetTest, TypeId,
4062 CastedCallee, StaticData);
4064 EmitCheck(std::make_pair(BitSetTest, SanitizerKind::CFIICall),
4065 "cfi_check_fail", StaticData,
4066 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4072 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
4073 CGM.getContext().VoidPtrTy);
4074 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4075 E->getDirectCallee(), /*ParamsToSkip*/ 0);
4077 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
4078 Args, FnType, /*isChainCall=*/Chain);
4081 // If the expression that denotes the called function has a type
4082 // that does not include a prototype, [the default argument
4083 // promotions are performed]. If the number of arguments does not
4084 // equal the number of parameters, the behavior is undefined. If
4085 // the function is defined with a type that includes a prototype,
4086 // and either the prototype ends with an ellipsis (, ...) or the
4087 // types of the arguments after promotion are not compatible with
4088 // the types of the parameters, the behavior is undefined. If the
4089 // function is defined with a type that does not include a
4090 // prototype, and the types of the arguments after promotion are
4091 // not compatible with those of the parameters after promotion,
4092 // the behavior is undefined [except in some trivial cases].
4093 // That is, in the general case, we should assume that a call
4094 // through an unprototyped function type works like a *non-variadic*
4095 // call. The way we make this work is to cast to the exact type
4096 // of the promoted arguments.
4098 // Chain calls use this same code path to add the invisible chain parameter
4099 // to the function type.
4100 if (isa<FunctionNoProtoType>(FnType) || Chain) {
4101 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
4102 CalleeTy = CalleeTy->getPointerTo();
4103 Callee = Builder.CreateBitCast(Callee, CalleeTy, "callee.knr.cast");
4106 return EmitCall(FnInfo, Callee, ReturnValue, Args,
4107 CGCalleeInfo(NonCanonicalFTP, TargetDecl));
4110 LValue CodeGenFunction::
4111 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
4112 Address BaseAddr = Address::invalid();
4113 if (E->getOpcode() == BO_PtrMemI) {
4114 BaseAddr = EmitPointerWithAlignment(E->getLHS());
4116 BaseAddr = EmitLValue(E->getLHS()).getAddress();
4119 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
4121 const MemberPointerType *MPT
4122 = E->getRHS()->getType()->getAs<MemberPointerType>();
4124 AlignmentSource AlignSource;
4125 Address MemberAddr =
4126 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT,
4129 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), AlignSource);
4132 /// Given the address of a temporary variable, produce an r-value of
4134 RValue CodeGenFunction::convertTempToRValue(Address addr,
4136 SourceLocation loc) {
4137 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
4138 switch (getEvaluationKind(type)) {
4140 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
4142 return lvalue.asAggregateRValue();
4144 return RValue::get(EmitLoadOfScalar(lvalue, loc));
4146 llvm_unreachable("bad evaluation kind");
4149 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
4150 assert(Val->getType()->isFPOrFPVectorTy());
4151 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
4154 llvm::MDBuilder MDHelper(getLLVMContext());
4155 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
4157 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
4161 struct LValueOrRValue {
4167 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
4168 const PseudoObjectExpr *E,
4170 AggValueSlot slot) {
4171 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
4173 // Find the result expression, if any.
4174 const Expr *resultExpr = E->getResultExpr();
4175 LValueOrRValue result;
4177 for (PseudoObjectExpr::const_semantics_iterator
4178 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
4179 const Expr *semantic = *i;
4181 // If this semantic expression is an opaque value, bind it
4182 // to the result of its source expression.
4183 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
4185 // If this is the result expression, we may need to evaluate
4186 // directly into the slot.
4187 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
4189 if (ov == resultExpr && ov->isRValue() && !forLValue &&
4190 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
4191 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
4193 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
4194 AlignmentSource::Decl);
4195 opaqueData = OVMA::bind(CGF, ov, LV);
4196 result.RV = slot.asRValue();
4198 // Otherwise, emit as normal.
4200 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
4202 // If this is the result, also evaluate the result now.
4203 if (ov == resultExpr) {
4205 result.LV = CGF.EmitLValue(ov);
4207 result.RV = CGF.EmitAnyExpr(ov, slot);
4211 opaques.push_back(opaqueData);
4213 // Otherwise, if the expression is the result, evaluate it
4214 // and remember the result.
4215 } else if (semantic == resultExpr) {
4217 result.LV = CGF.EmitLValue(semantic);
4219 result.RV = CGF.EmitAnyExpr(semantic, slot);
4221 // Otherwise, evaluate the expression in an ignored context.
4223 CGF.EmitIgnoredExpr(semantic);
4227 // Unbind all the opaques now.
4228 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
4229 opaques[i].unbind(CGF);
4234 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
4235 AggValueSlot slot) {
4236 return emitPseudoObjectExpr(*this, E, false, slot).RV;
4239 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
4240 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;