1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This contains code to emit Expr nodes as LLVM code.
11 //===----------------------------------------------------------------------===//
15 #include "CGCleanup.h"
16 #include "CGDebugInfo.h"
17 #include "CGObjCRuntime.h"
18 #include "CGOpenMPRuntime.h"
19 #include "CGRecordLayout.h"
20 #include "CodeGenFunction.h"
21 #include "CodeGenModule.h"
22 #include "ConstantEmitter.h"
23 #include "TargetInfo.h"
24 #include "clang/AST/ASTContext.h"
25 #include "clang/AST/Attr.h"
26 #include "clang/AST/DeclObjC.h"
27 #include "clang/AST/NSAPI.h"
28 #include "clang/Basic/Builtins.h"
29 #include "clang/Basic/CodeGenOptions.h"
30 #include "llvm/ADT/Hashing.h"
31 #include "llvm/ADT/StringExtras.h"
32 #include "llvm/IR/DataLayout.h"
33 #include "llvm/IR/Intrinsics.h"
34 #include "llvm/IR/LLVMContext.h"
35 #include "llvm/IR/MDBuilder.h"
36 #include "llvm/Support/ConvertUTF.h"
37 #include "llvm/Support/MathExtras.h"
38 #include "llvm/Support/Path.h"
39 #include "llvm/Transforms/Utils/SanitizerStats.h"
43 using namespace clang;
44 using namespace CodeGen;
46 //===--------------------------------------------------------------------===//
47 // Miscellaneous Helper Methods
48 //===--------------------------------------------------------------------===//
50 llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
51 unsigned addressSpace =
52 cast<llvm::PointerType>(value->getType())->getAddressSpace();
54 llvm::PointerType *destType = Int8PtrTy;
56 destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
58 if (value->getType() == destType) return value;
59 return Builder.CreateBitCast(value, destType);
62 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
64 Address CodeGenFunction::CreateTempAllocaWithoutCast(llvm::Type *Ty,
67 llvm::Value *ArraySize) {
68 auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
69 Alloca->setAlignment(Align.getAsAlign());
70 return Address(Alloca, Align);
73 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
74 /// block. The alloca is casted to default address space if necessary.
75 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
77 llvm::Value *ArraySize,
78 Address *AllocaAddr) {
79 auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
82 llvm::Value *V = Alloca.getPointer();
83 // Alloca always returns a pointer in alloca address space, which may
84 // be different from the type defined by the language. For example,
85 // in C++ the auto variables are in the default address space. Therefore
86 // cast alloca to the default address space when necessary.
87 if (getASTAllocaAddressSpace() != LangAS::Default) {
88 auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
89 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
90 // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
91 // otherwise alloca is inserted at the current insertion point of the
94 Builder.SetInsertPoint(AllocaInsertPt);
95 V = getTargetHooks().performAddrSpaceCast(
96 *this, V, getASTAllocaAddressSpace(), LangAS::Default,
97 Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
100 return Address(V, Align);
103 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
104 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
105 /// insertion point of the builder.
106 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
108 llvm::Value *ArraySize) {
110 return Builder.CreateAlloca(Ty, ArraySize, Name);
111 return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
112 ArraySize, Name, AllocaInsertPt);
115 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
116 /// default alignment of the corresponding LLVM type, which is *not*
117 /// guaranteed to be related in any way to the expected alignment of
118 /// an AST type that might have been lowered to Ty.
119 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
122 CharUnits::fromQuantity(CGM.getDataLayout().getABITypeAlignment(Ty));
123 return CreateTempAlloca(Ty, Align, Name);
126 void CodeGenFunction::InitTempAlloca(Address Var, llvm::Value *Init) {
127 assert(isa<llvm::AllocaInst>(Var.getPointer()));
128 auto *Store = new llvm::StoreInst(Init, Var.getPointer());
129 Store->setAlignment(Var.getAlignment().getAsAlign());
130 llvm::BasicBlock *Block = AllocaInsertPt->getParent();
131 Block->getInstList().insertAfter(AllocaInsertPt->getIterator(), Store);
134 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
135 CharUnits Align = getContext().getTypeAlignInChars(Ty);
136 return CreateTempAlloca(ConvertType(Ty), Align, Name);
139 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name,
141 // FIXME: Should we prefer the preferred type alignment here?
142 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
145 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
146 const Twine &Name, Address *Alloca) {
147 return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
148 /*ArraySize=*/nullptr, Alloca);
151 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty, CharUnits Align,
153 return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
156 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty,
158 return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
162 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
163 /// expression and compare the result against zero, returning an Int1Ty value.
164 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
165 PGO.setCurrentStmt(E);
166 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
167 llvm::Value *MemPtr = EmitScalarExpr(E);
168 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
171 QualType BoolTy = getContext().BoolTy;
172 SourceLocation Loc = E->getExprLoc();
173 if (!E->getType()->isAnyComplexType())
174 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
176 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
180 /// EmitIgnoredExpr - Emit code to compute the specified expression,
181 /// ignoring the result.
182 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
184 return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
186 // Just emit it as an l-value and drop the result.
190 /// EmitAnyExpr - Emit code to compute the specified expression which
191 /// can have any type. The result is returned as an RValue struct.
192 /// If this is an aggregate expression, AggSlot indicates where the
193 /// result should be returned.
194 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
195 AggValueSlot aggSlot,
197 switch (getEvaluationKind(E->getType())) {
199 return RValue::get(EmitScalarExpr(E, ignoreResult));
201 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
203 if (!ignoreResult && aggSlot.isIgnored())
204 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
205 EmitAggExpr(E, aggSlot);
206 return aggSlot.asRValue();
208 llvm_unreachable("bad evaluation kind");
211 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
212 /// always be accessible even if no aggregate location is provided.
213 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
214 AggValueSlot AggSlot = AggValueSlot::ignored();
216 if (hasAggregateEvaluationKind(E->getType()))
217 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
218 return EmitAnyExpr(E, AggSlot);
221 /// EmitAnyExprToMem - Evaluate an expression into a given memory
223 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
227 // FIXME: This function should take an LValue as an argument.
228 switch (getEvaluationKind(E->getType())) {
230 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
234 case TEK_Aggregate: {
235 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
236 AggValueSlot::IsDestructed_t(IsInit),
237 AggValueSlot::DoesNotNeedGCBarriers,
238 AggValueSlot::IsAliased_t(!IsInit),
239 AggValueSlot::MayOverlap));
244 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
245 LValue LV = MakeAddrLValue(Location, E->getType());
246 EmitStoreThroughLValue(RV, LV);
250 llvm_unreachable("bad evaluation kind");
254 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
255 const Expr *E, Address ReferenceTemporary) {
256 // Objective-C++ ARC:
257 // If we are binding a reference to a temporary that has ownership, we
258 // need to perform retain/release operations on the temporary.
260 // FIXME: This should be looking at E, not M.
261 if (auto Lifetime = M->getType().getObjCLifetime()) {
263 case Qualifiers::OCL_None:
264 case Qualifiers::OCL_ExplicitNone:
265 // Carry on to normal cleanup handling.
268 case Qualifiers::OCL_Autoreleasing:
269 // Nothing to do; cleaned up by an autorelease pool.
272 case Qualifiers::OCL_Strong:
273 case Qualifiers::OCL_Weak:
274 switch (StorageDuration Duration = M->getStorageDuration()) {
276 // Note: we intentionally do not register a cleanup to release
277 // the object on program termination.
281 // FIXME: We should probably register a cleanup in this case.
285 case SD_FullExpression:
286 CodeGenFunction::Destroyer *Destroy;
287 CleanupKind CleanupKind;
288 if (Lifetime == Qualifiers::OCL_Strong) {
289 const ValueDecl *VD = M->getExtendingDecl();
291 VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
292 CleanupKind = CGF.getARCCleanupKind();
293 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
294 : &CodeGenFunction::destroyARCStrongImprecise;
296 // __weak objects always get EH cleanups; otherwise, exceptions
297 // could cause really nasty crashes instead of mere leaks.
298 CleanupKind = NormalAndEHCleanup;
299 Destroy = &CodeGenFunction::destroyARCWeak;
301 if (Duration == SD_FullExpression)
302 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
303 M->getType(), *Destroy,
304 CleanupKind & EHCleanup);
306 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
308 *Destroy, CleanupKind & EHCleanup);
312 llvm_unreachable("temporary cannot have dynamic storage duration");
314 llvm_unreachable("unknown storage duration");
318 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
319 if (const RecordType *RT =
320 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
321 // Get the destructor for the reference temporary.
322 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
323 if (!ClassDecl->hasTrivialDestructor())
324 ReferenceTemporaryDtor = ClassDecl->getDestructor();
327 if (!ReferenceTemporaryDtor)
330 // Call the destructor for the temporary.
331 switch (M->getStorageDuration()) {
334 llvm::FunctionCallee CleanupFn;
335 llvm::Constant *CleanupArg;
336 if (E->getType()->isArrayType()) {
337 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
338 ReferenceTemporary, E->getType(),
339 CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
340 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
341 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
343 CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
344 GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
345 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
347 CGF.CGM.getCXXABI().registerGlobalDtor(
348 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
352 case SD_FullExpression:
353 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
354 CodeGenFunction::destroyCXXObject,
355 CGF.getLangOpts().Exceptions);
359 CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
360 ReferenceTemporary, E->getType(),
361 CodeGenFunction::destroyCXXObject,
362 CGF.getLangOpts().Exceptions);
366 llvm_unreachable("temporary cannot have dynamic storage duration");
370 static Address createReferenceTemporary(CodeGenFunction &CGF,
371 const MaterializeTemporaryExpr *M,
373 Address *Alloca = nullptr) {
374 auto &TCG = CGF.getTargetHooks();
375 switch (M->getStorageDuration()) {
376 case SD_FullExpression:
378 // If we have a constant temporary array or record try to promote it into a
379 // constant global under the same rules a normal constant would've been
380 // promoted. This is easier on the optimizer and generally emits fewer
382 QualType Ty = Inner->getType();
383 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
384 (Ty->isArrayType() || Ty->isRecordType()) &&
385 CGF.CGM.isTypeConstant(Ty, true))
386 if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
387 if (auto AddrSpace = CGF.getTarget().getConstantAddressSpace()) {
388 auto AS = AddrSpace.getValue();
389 auto *GV = new llvm::GlobalVariable(
390 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
391 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
392 llvm::GlobalValue::NotThreadLocal,
393 CGF.getContext().getTargetAddressSpace(AS));
394 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
395 GV->setAlignment(alignment.getAsAlign());
396 llvm::Constant *C = GV;
397 if (AS != LangAS::Default)
398 C = TCG.performAddrSpaceCast(
399 CGF.CGM, GV, AS, LangAS::Default,
400 GV->getValueType()->getPointerTo(
401 CGF.getContext().getTargetAddressSpace(LangAS::Default)));
402 // FIXME: Should we put the new global into a COMDAT?
403 return Address(C, alignment);
406 return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
410 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
413 llvm_unreachable("temporary can't have dynamic storage duration");
415 llvm_unreachable("unknown storage duration");
418 LValue CodeGenFunction::
419 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
420 const Expr *E = M->getSubExpr();
422 assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
423 !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
424 "Reference should never be pseudo-strong!");
426 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
427 // as that will cause the lifetime adjustment to be lost for ARC
428 auto ownership = M->getType().getObjCLifetime();
429 if (ownership != Qualifiers::OCL_None &&
430 ownership != Qualifiers::OCL_ExplicitNone) {
431 Address Object = createReferenceTemporary(*this, M, E);
432 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
433 Object = Address(llvm::ConstantExpr::getBitCast(Var,
434 ConvertTypeForMem(E->getType())
435 ->getPointerTo(Object.getAddressSpace())),
436 Object.getAlignment());
438 // createReferenceTemporary will promote the temporary to a global with a
439 // constant initializer if it can. It can only do this to a value of
440 // ARC-manageable type if the value is global and therefore "immune" to
441 // ref-counting operations. Therefore we have no need to emit either a
442 // dynamic initialization or a cleanup and we can just return the address
444 if (Var->hasInitializer())
445 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
447 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
449 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
450 AlignmentSource::Decl);
452 switch (getEvaluationKind(E->getType())) {
453 default: llvm_unreachable("expected scalar or aggregate expression");
455 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
457 case TEK_Aggregate: {
458 EmitAggExpr(E, AggValueSlot::forAddr(Object,
459 E->getType().getQualifiers(),
460 AggValueSlot::IsDestructed,
461 AggValueSlot::DoesNotNeedGCBarriers,
462 AggValueSlot::IsNotAliased,
463 AggValueSlot::DoesNotOverlap));
468 pushTemporaryCleanup(*this, M, E, Object);
472 SmallVector<const Expr *, 2> CommaLHSs;
473 SmallVector<SubobjectAdjustment, 2> Adjustments;
474 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
476 for (const auto &Ignored : CommaLHSs)
477 EmitIgnoredExpr(Ignored);
479 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
480 if (opaque->getType()->isRecordType()) {
481 assert(Adjustments.empty());
482 return EmitOpaqueValueLValue(opaque);
486 // Create and initialize the reference temporary.
487 Address Alloca = Address::invalid();
488 Address Object = createReferenceTemporary(*this, M, E, &Alloca);
489 if (auto *Var = dyn_cast<llvm::GlobalVariable>(
490 Object.getPointer()->stripPointerCasts())) {
491 Object = Address(llvm::ConstantExpr::getBitCast(
492 cast<llvm::Constant>(Object.getPointer()),
493 ConvertTypeForMem(E->getType())->getPointerTo()),
494 Object.getAlignment());
495 // If the temporary is a global and has a constant initializer or is a
496 // constant temporary that we promoted to a global, we may have already
498 if (!Var->hasInitializer()) {
499 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
500 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
503 switch (M->getStorageDuration()) {
505 if (auto *Size = EmitLifetimeStart(
506 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
507 Alloca.getPointer())) {
508 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
513 case SD_FullExpression: {
514 if (!ShouldEmitLifetimeMarkers)
517 // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
518 // marker. Instead, start the lifetime of a conditional temporary earlier
519 // so that it's unconditional. Don't do this with sanitizers which need
520 // more precise lifetime marks.
521 ConditionalEvaluation *OldConditional = nullptr;
522 CGBuilderTy::InsertPoint OldIP;
523 if (isInConditionalBranch() && !E->getType().isDestructedType() &&
524 !SanOpts.has(SanitizerKind::HWAddress) &&
525 !SanOpts.has(SanitizerKind::Memory) &&
526 !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) {
527 OldConditional = OutermostConditional;
528 OutermostConditional = nullptr;
530 OldIP = Builder.saveIP();
531 llvm::BasicBlock *Block = OldConditional->getStartingBlock();
532 Builder.restoreIP(CGBuilderTy::InsertPoint(
533 Block, llvm::BasicBlock::iterator(Block->back())));
536 if (auto *Size = EmitLifetimeStart(
537 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
538 Alloca.getPointer())) {
539 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
543 if (OldConditional) {
544 OutermostConditional = OldConditional;
545 Builder.restoreIP(OldIP);
553 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
555 pushTemporaryCleanup(*this, M, E, Object);
557 // Perform derived-to-base casts and/or field accesses, to get from the
558 // temporary object we created (and, potentially, for which we extended
559 // the lifetime) to the subobject we're binding the reference to.
560 for (unsigned I = Adjustments.size(); I != 0; --I) {
561 SubobjectAdjustment &Adjustment = Adjustments[I-1];
562 switch (Adjustment.Kind) {
563 case SubobjectAdjustment::DerivedToBaseAdjustment:
565 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
566 Adjustment.DerivedToBase.BasePath->path_begin(),
567 Adjustment.DerivedToBase.BasePath->path_end(),
568 /*NullCheckValue=*/ false, E->getExprLoc());
571 case SubobjectAdjustment::FieldAdjustment: {
572 LValue LV = MakeAddrLValue(Object, E->getType(), AlignmentSource::Decl);
573 LV = EmitLValueForField(LV, Adjustment.Field);
574 assert(LV.isSimple() &&
575 "materialized temporary field is not a simple lvalue");
576 Object = LV.getAddress(*this);
580 case SubobjectAdjustment::MemberPointerAdjustment: {
581 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
582 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
589 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
593 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
594 // Emit the expression as an lvalue.
595 LValue LV = EmitLValue(E);
596 assert(LV.isSimple());
597 llvm::Value *Value = LV.getPointer(*this);
599 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
600 // C++11 [dcl.ref]p5 (as amended by core issue 453):
601 // If a glvalue to which a reference is directly bound designates neither
602 // an existing object or function of an appropriate type nor a region of
603 // storage of suitable size and alignment to contain an object of the
604 // reference's type, the behavior is undefined.
605 QualType Ty = E->getType();
606 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
609 return RValue::get(Value);
613 /// getAccessedFieldNo - Given an encoded value and a result number, return the
614 /// input field number being accessed.
615 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
616 const llvm::Constant *Elts) {
617 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
621 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
622 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
624 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
625 llvm::Value *K47 = Builder.getInt64(47);
626 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
627 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
628 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
629 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
630 return Builder.CreateMul(B1, KMul);
633 bool CodeGenFunction::isNullPointerAllowed(TypeCheckKind TCK) {
634 return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
635 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation;
638 bool CodeGenFunction::isVptrCheckRequired(TypeCheckKind TCK, QualType Ty) {
639 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
640 return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
641 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
642 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
643 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation);
646 bool CodeGenFunction::sanitizePerformTypeCheck() const {
647 return SanOpts.has(SanitizerKind::Null) |
648 SanOpts.has(SanitizerKind::Alignment) |
649 SanOpts.has(SanitizerKind::ObjectSize) |
650 SanOpts.has(SanitizerKind::Vptr);
653 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
654 llvm::Value *Ptr, QualType Ty,
656 SanitizerSet SkippedChecks,
657 llvm::Value *ArraySize) {
658 if (!sanitizePerformTypeCheck())
661 // Don't check pointers outside the default address space. The null check
662 // isn't correct, the object-size check isn't supported by LLVM, and we can't
663 // communicate the addresses to the runtime handler for the vptr check.
664 if (Ptr->getType()->getPointerAddressSpace())
667 // Don't check pointers to volatile data. The behavior here is implementation-
669 if (Ty.isVolatileQualified())
672 SanitizerScope SanScope(this);
674 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
675 llvm::BasicBlock *Done = nullptr;
677 // Quickly determine whether we have a pointer to an alloca. It's possible
678 // to skip null checks, and some alignment checks, for these pointers. This
679 // can reduce compile-time significantly.
680 auto PtrToAlloca = dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCasts());
682 llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
683 llvm::Value *IsNonNull = nullptr;
684 bool IsGuaranteedNonNull =
685 SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
686 bool AllowNullPointers = isNullPointerAllowed(TCK);
687 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
688 !IsGuaranteedNonNull) {
689 // The glvalue must not be an empty glvalue.
690 IsNonNull = Builder.CreateIsNotNull(Ptr);
692 // The IR builder can constant-fold the null check if the pointer points to
694 IsGuaranteedNonNull = IsNonNull == True;
696 // Skip the null check if the pointer is known to be non-null.
697 if (!IsGuaranteedNonNull) {
698 if (AllowNullPointers) {
699 // When performing pointer casts, it's OK if the value is null.
700 // Skip the remaining checks in that case.
701 Done = createBasicBlock("null");
702 llvm::BasicBlock *Rest = createBasicBlock("not.null");
703 Builder.CreateCondBr(IsNonNull, Rest, Done);
706 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
711 if (SanOpts.has(SanitizerKind::ObjectSize) &&
712 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
713 !Ty->isIncompleteType()) {
714 uint64_t TySize = getContext().getTypeSizeInChars(Ty).getQuantity();
715 llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
717 Size = Builder.CreateMul(Size, ArraySize);
719 // Degenerate case: new X[0] does not need an objectsize check.
720 llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
721 if (!ConstantSize || !ConstantSize->isNullValue()) {
722 // The glvalue must refer to a large enough storage region.
723 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
725 // FIXME: Get object address space
726 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
727 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
728 llvm::Value *Min = Builder.getFalse();
729 llvm::Value *NullIsUnknown = Builder.getFalse();
730 llvm::Value *Dynamic = Builder.getFalse();
731 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
732 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
733 Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown, Dynamic}), Size);
734 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
738 uint64_t AlignVal = 0;
739 llvm::Value *PtrAsInt = nullptr;
741 if (SanOpts.has(SanitizerKind::Alignment) &&
742 !SkippedChecks.has(SanitizerKind::Alignment)) {
743 AlignVal = Alignment.getQuantity();
744 if (!Ty->isIncompleteType() && !AlignVal)
745 AlignVal = getContext().getTypeAlignInChars(Ty).getQuantity();
747 // The glvalue must be suitably aligned.
749 (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
750 PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
751 llvm::Value *Align = Builder.CreateAnd(
752 PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
753 llvm::Value *Aligned =
754 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
756 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
760 if (Checks.size() > 0) {
761 // Make sure we're not losing information. Alignment needs to be a power of
763 assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
764 llvm::Constant *StaticData[] = {
765 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
766 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
767 llvm::ConstantInt::get(Int8Ty, TCK)};
768 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
769 PtrAsInt ? PtrAsInt : Ptr);
772 // If possible, check that the vptr indicates that there is a subobject of
773 // type Ty at offset zero within this object.
775 // C++11 [basic.life]p5,6:
776 // [For storage which does not refer to an object within its lifetime]
777 // The program has undefined behavior if:
778 // -- the [pointer or glvalue] is used to access a non-static data member
779 // or call a non-static member function
780 if (SanOpts.has(SanitizerKind::Vptr) &&
781 !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
782 // Ensure that the pointer is non-null before loading it. If there is no
783 // compile-time guarantee, reuse the run-time null check or emit a new one.
784 if (!IsGuaranteedNonNull) {
786 IsNonNull = Builder.CreateIsNotNull(Ptr);
788 Done = createBasicBlock("vptr.null");
789 llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
790 Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
791 EmitBlock(VptrNotNull);
794 // Compute a hash of the mangled name of the type.
796 // FIXME: This is not guaranteed to be deterministic! Move to a
797 // fingerprinting mechanism once LLVM provides one. For the time
798 // being the implementation happens to be deterministic.
799 SmallString<64> MangledName;
800 llvm::raw_svector_ostream Out(MangledName);
801 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
804 // Blacklist based on the mangled type.
805 if (!CGM.getContext().getSanitizerBlacklist().isBlacklistedType(
806 SanitizerKind::Vptr, Out.str())) {
807 llvm::hash_code TypeHash = hash_value(Out.str());
809 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
810 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
811 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
812 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
813 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
814 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
816 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
817 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
819 // Look the hash up in our cache.
820 const int CacheSize = 128;
821 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
822 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
823 "__ubsan_vptr_type_cache");
824 llvm::Value *Slot = Builder.CreateAnd(Hash,
825 llvm::ConstantInt::get(IntPtrTy,
827 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
828 llvm::Value *CacheVal =
829 Builder.CreateAlignedLoad(Builder.CreateInBoundsGEP(Cache, Indices),
832 // If the hash isn't in the cache, call a runtime handler to perform the
833 // hard work of checking whether the vptr is for an object of the right
834 // type. This will either fill in the cache and return, or produce a
836 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
837 llvm::Constant *StaticData[] = {
838 EmitCheckSourceLocation(Loc),
839 EmitCheckTypeDescriptor(Ty),
840 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
841 llvm::ConstantInt::get(Int8Ty, TCK)
843 llvm::Value *DynamicData[] = { Ptr, Hash };
844 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
845 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
851 Builder.CreateBr(Done);
856 /// Determine whether this expression refers to a flexible array member in a
857 /// struct. We disable array bounds checks for such members.
858 static bool isFlexibleArrayMemberExpr(const Expr *E) {
859 // For compatibility with existing code, we treat arrays of length 0 or
860 // 1 as flexible array members.
861 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
862 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
863 if (CAT->getSize().ugt(1))
865 } else if (!isa<IncompleteArrayType>(AT))
868 E = E->IgnoreParens();
870 // A flexible array member must be the last member in the class.
871 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
872 // FIXME: If the base type of the member expr is not FD->getParent(),
873 // this should not be treated as a flexible array member access.
874 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
875 RecordDecl::field_iterator FI(
876 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
877 return ++FI == FD->getParent()->field_end();
879 } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
880 return IRE->getDecl()->getNextIvar() == nullptr;
886 llvm::Value *CodeGenFunction::LoadPassedObjectSize(const Expr *E,
888 ASTContext &C = getContext();
889 uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
893 auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
897 auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
901 auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
905 // Don't load the size if it's a lower bound.
906 int POSType = POSAttr->getType();
907 if (POSType != 0 && POSType != 1)
910 // Find the implicit size parameter.
911 auto PassedSizeIt = SizeArguments.find(ParamDecl);
912 if (PassedSizeIt == SizeArguments.end())
915 const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
916 assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
917 Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
918 llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
919 C.getSizeType(), E->getExprLoc());
920 llvm::Value *SizeOfElement =
921 llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
922 return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
925 /// If Base is known to point to the start of an array, return the length of
926 /// that array. Return 0 if the length cannot be determined.
927 static llvm::Value *getArrayIndexingBound(
928 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
929 // For the vector indexing extension, the bound is the number of elements.
930 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
931 IndexedType = Base->getType();
932 return CGF.Builder.getInt32(VT->getNumElements());
935 Base = Base->IgnoreParens();
937 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
938 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
939 !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
940 IndexedType = CE->getSubExpr()->getType();
941 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
942 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
943 return CGF.Builder.getInt(CAT->getSize());
944 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
945 return CGF.getVLASize(VAT).NumElts;
946 // Ignore pass_object_size here. It's not applicable on decayed pointers.
950 QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
951 if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
952 IndexedType = Base->getType();
959 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
960 llvm::Value *Index, QualType IndexType,
962 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
963 "should not be called unless adding bounds checks");
964 SanitizerScope SanScope(this);
966 QualType IndexedType;
967 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
971 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
972 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
973 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
975 llvm::Constant *StaticData[] = {
976 EmitCheckSourceLocation(E->getExprLoc()),
977 EmitCheckTypeDescriptor(IndexedType),
978 EmitCheckTypeDescriptor(IndexType)
980 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
981 : Builder.CreateICmpULE(IndexVal, BoundVal);
982 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
983 SanitizerHandler::OutOfBounds, StaticData, Index);
987 CodeGenFunction::ComplexPairTy CodeGenFunction::
988 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
989 bool isInc, bool isPre) {
990 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
992 llvm::Value *NextVal;
993 if (isa<llvm::IntegerType>(InVal.first->getType())) {
994 uint64_t AmountVal = isInc ? 1 : -1;
995 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
997 // Add the inc/dec to the real part.
998 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1000 QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
1001 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1004 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1006 // Add the inc/dec to the real part.
1007 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1010 ComplexPairTy IncVal(NextVal, InVal.second);
1012 // Store the updated result through the lvalue.
1013 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1014 if (getLangOpts().OpenMP)
1015 CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this,
1018 // If this is a postinc, return the value read from memory, otherwise use the
1020 return isPre ? IncVal : InVal;
1023 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
1024 CodeGenFunction *CGF) {
1025 // Bind VLAs in the cast type.
1026 if (CGF && E->getType()->isVariablyModifiedType())
1027 CGF->EmitVariablyModifiedType(E->getType());
1029 if (CGDebugInfo *DI = getModuleDebugInfo())
1030 DI->EmitExplicitCastType(E->getType());
1033 //===----------------------------------------------------------------------===//
1034 // LValue Expression Emission
1035 //===----------------------------------------------------------------------===//
1037 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1038 /// derive a more accurate bound on the alignment of the pointer.
1039 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E,
1040 LValueBaseInfo *BaseInfo,
1041 TBAAAccessInfo *TBAAInfo) {
1042 // We allow this with ObjC object pointers because of fragile ABIs.
1043 assert(E->getType()->isPointerType() ||
1044 E->getType()->isObjCObjectPointerType());
1045 E = E->IgnoreParens();
1048 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1049 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1050 CGM.EmitExplicitCastExprType(ECE, this);
1052 switch (CE->getCastKind()) {
1053 // Non-converting casts (but not C's implicit conversion from void*).
1056 case CK_AddressSpaceConversion:
1057 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1058 if (PtrTy->getPointeeType()->isVoidType())
1061 LValueBaseInfo InnerBaseInfo;
1062 TBAAAccessInfo InnerTBAAInfo;
1063 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1066 if (BaseInfo) *BaseInfo = InnerBaseInfo;
1067 if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1069 if (isa<ExplicitCastExpr>(CE)) {
1070 LValueBaseInfo TargetTypeBaseInfo;
1071 TBAAAccessInfo TargetTypeTBAAInfo;
1072 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(),
1073 &TargetTypeBaseInfo,
1074 &TargetTypeTBAAInfo);
1076 *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1077 TargetTypeTBAAInfo);
1078 // If the source l-value is opaque, honor the alignment of the
1080 if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1082 BaseInfo->mergeForCast(TargetTypeBaseInfo);
1083 Addr = Address(Addr.getPointer(), Align);
1087 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1088 CE->getCastKind() == CK_BitCast) {
1089 if (auto PT = E->getType()->getAs<PointerType>())
1090 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1092 CodeGenFunction::CFITCK_UnrelatedCast,
1095 return CE->getCastKind() != CK_AddressSpaceConversion
1096 ? Builder.CreateBitCast(Addr, ConvertType(E->getType()))
1097 : Builder.CreateAddrSpaceCast(Addr,
1098 ConvertType(E->getType()));
1102 // Array-to-pointer decay.
1103 case CK_ArrayToPointerDecay:
1104 return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1106 // Derived-to-base conversions.
1107 case CK_UncheckedDerivedToBase:
1108 case CK_DerivedToBase: {
1109 // TODO: Support accesses to members of base classes in TBAA. For now, we
1110 // conservatively pretend that the complete object is of the base class
1113 *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1114 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1115 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1116 return GetAddressOfBaseClass(Addr, Derived,
1117 CE->path_begin(), CE->path_end(),
1118 ShouldNullCheckClassCastValue(CE),
1122 // TODO: Is there any reason to treat base-to-derived conversions
1130 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1131 if (UO->getOpcode() == UO_AddrOf) {
1132 LValue LV = EmitLValue(UO->getSubExpr());
1133 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1134 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1135 return LV.getAddress(*this);
1139 // TODO: conditional operators, comma.
1141 // Otherwise, use the alignment of the type.
1142 CharUnits Align = getNaturalPointeeTypeAlignment(E->getType(), BaseInfo,
1144 return Address(EmitScalarExpr(E), Align);
1147 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
1148 if (Ty->isVoidType())
1149 return RValue::get(nullptr);
1151 switch (getEvaluationKind(Ty)) {
1154 ConvertType(Ty->castAs<ComplexType>()->getElementType());
1155 llvm::Value *U = llvm::UndefValue::get(EltTy);
1156 return RValue::getComplex(std::make_pair(U, U));
1159 // If this is a use of an undefined aggregate type, the aggregate must have an
1160 // identifiable address. Just because the contents of the value are undefined
1161 // doesn't mean that the address can't be taken and compared.
1162 case TEK_Aggregate: {
1163 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1164 return RValue::getAggregate(DestPtr);
1168 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1170 llvm_unreachable("bad evaluation kind");
1173 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
1175 ErrorUnsupported(E, Name);
1176 return GetUndefRValue(E->getType());
1179 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
1181 ErrorUnsupported(E, Name);
1182 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1183 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1187 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
1188 const Expr *Base = Obj;
1189 while (!isa<CXXThisExpr>(Base)) {
1190 // The result of a dynamic_cast can be null.
1191 if (isa<CXXDynamicCastExpr>(Base))
1194 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1195 Base = CE->getSubExpr();
1196 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1197 Base = PE->getSubExpr();
1198 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1199 if (UO->getOpcode() == UO_Extension)
1200 Base = UO->getSubExpr();
1210 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1212 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1213 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1216 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1217 SanitizerSet SkippedChecks;
1218 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1219 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1221 SkippedChecks.set(SanitizerKind::Alignment, true);
1222 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1223 SkippedChecks.set(SanitizerKind::Null, true);
1225 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(*this), E->getType(),
1226 LV.getAlignment(), SkippedChecks);
1231 /// EmitLValue - Emit code to compute a designator that specifies the location
1232 /// of the expression.
1234 /// This can return one of two things: a simple address or a bitfield reference.
1235 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1236 /// an LLVM pointer type.
1238 /// If this returns a bitfield reference, nothing about the pointee type of the
1239 /// LLVM value is known: For example, it may not be a pointer to an integer.
1241 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1242 /// this method guarantees that the returned pointer type will point to an LLVM
1243 /// type of the same size of the lvalue's type. If the lvalue has a variable
1244 /// length type, this is not possible.
1246 LValue CodeGenFunction::EmitLValue(const Expr *E) {
1247 ApplyDebugLocation DL(*this, E);
1248 switch (E->getStmtClass()) {
1249 default: return EmitUnsupportedLValue(E, "l-value expression");
1251 case Expr::ObjCPropertyRefExprClass:
1252 llvm_unreachable("cannot emit a property reference directly");
1254 case Expr::ObjCSelectorExprClass:
1255 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1256 case Expr::ObjCIsaExprClass:
1257 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1258 case Expr::BinaryOperatorClass:
1259 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1260 case Expr::CompoundAssignOperatorClass: {
1261 QualType Ty = E->getType();
1262 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1263 Ty = AT->getValueType();
1264 if (!Ty->isAnyComplexType())
1265 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1266 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1268 case Expr::CallExprClass:
1269 case Expr::CXXMemberCallExprClass:
1270 case Expr::CXXOperatorCallExprClass:
1271 case Expr::UserDefinedLiteralClass:
1272 return EmitCallExprLValue(cast<CallExpr>(E));
1273 case Expr::CXXRewrittenBinaryOperatorClass:
1274 return EmitLValue(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm());
1275 case Expr::VAArgExprClass:
1276 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1277 case Expr::DeclRefExprClass:
1278 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1279 case Expr::ConstantExprClass:
1280 return EmitLValue(cast<ConstantExpr>(E)->getSubExpr());
1281 case Expr::ParenExprClass:
1282 return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1283 case Expr::GenericSelectionExprClass:
1284 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1285 case Expr::PredefinedExprClass:
1286 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1287 case Expr::StringLiteralClass:
1288 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1289 case Expr::ObjCEncodeExprClass:
1290 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1291 case Expr::PseudoObjectExprClass:
1292 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1293 case Expr::InitListExprClass:
1294 return EmitInitListLValue(cast<InitListExpr>(E));
1295 case Expr::CXXTemporaryObjectExprClass:
1296 case Expr::CXXConstructExprClass:
1297 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1298 case Expr::CXXBindTemporaryExprClass:
1299 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1300 case Expr::CXXUuidofExprClass:
1301 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1302 case Expr::LambdaExprClass:
1303 return EmitAggExprToLValue(E);
1305 case Expr::ExprWithCleanupsClass: {
1306 const auto *cleanups = cast<ExprWithCleanups>(E);
1307 enterFullExpression(cleanups);
1308 RunCleanupsScope Scope(*this);
1309 LValue LV = EmitLValue(cleanups->getSubExpr());
1310 if (LV.isSimple()) {
1311 // Defend against branches out of gnu statement expressions surrounded by
1313 llvm::Value *V = LV.getPointer(*this);
1314 Scope.ForceCleanup({&V});
1315 return LValue::MakeAddr(Address(V, LV.getAlignment()), LV.getType(),
1316 getContext(), LV.getBaseInfo(), LV.getTBAAInfo());
1318 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1319 // bitfield lvalue or some other non-simple lvalue?
1323 case Expr::CXXDefaultArgExprClass: {
1324 auto *DAE = cast<CXXDefaultArgExpr>(E);
1325 CXXDefaultArgExprScope Scope(*this, DAE);
1326 return EmitLValue(DAE->getExpr());
1328 case Expr::CXXDefaultInitExprClass: {
1329 auto *DIE = cast<CXXDefaultInitExpr>(E);
1330 CXXDefaultInitExprScope Scope(*this, DIE);
1331 return EmitLValue(DIE->getExpr());
1333 case Expr::CXXTypeidExprClass:
1334 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1336 case Expr::ObjCMessageExprClass:
1337 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1338 case Expr::ObjCIvarRefExprClass:
1339 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1340 case Expr::StmtExprClass:
1341 return EmitStmtExprLValue(cast<StmtExpr>(E));
1342 case Expr::UnaryOperatorClass:
1343 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1344 case Expr::ArraySubscriptExprClass:
1345 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1346 case Expr::OMPArraySectionExprClass:
1347 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1348 case Expr::ExtVectorElementExprClass:
1349 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1350 case Expr::MemberExprClass:
1351 return EmitMemberExpr(cast<MemberExpr>(E));
1352 case Expr::CompoundLiteralExprClass:
1353 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1354 case Expr::ConditionalOperatorClass:
1355 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1356 case Expr::BinaryConditionalOperatorClass:
1357 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1358 case Expr::ChooseExprClass:
1359 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1360 case Expr::OpaqueValueExprClass:
1361 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1362 case Expr::SubstNonTypeTemplateParmExprClass:
1363 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1364 case Expr::ImplicitCastExprClass:
1365 case Expr::CStyleCastExprClass:
1366 case Expr::CXXFunctionalCastExprClass:
1367 case Expr::CXXStaticCastExprClass:
1368 case Expr::CXXDynamicCastExprClass:
1369 case Expr::CXXReinterpretCastExprClass:
1370 case Expr::CXXConstCastExprClass:
1371 case Expr::ObjCBridgedCastExprClass:
1372 return EmitCastLValue(cast<CastExpr>(E));
1374 case Expr::MaterializeTemporaryExprClass:
1375 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1377 case Expr::CoawaitExprClass:
1378 return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1379 case Expr::CoyieldExprClass:
1380 return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1384 /// Given an object of the given canonical type, can we safely copy a
1385 /// value out of it based on its initializer?
1386 static bool isConstantEmittableObjectType(QualType type) {
1387 assert(type.isCanonical());
1388 assert(!type->isReferenceType());
1390 // Must be const-qualified but non-volatile.
1391 Qualifiers qs = type.getLocalQualifiers();
1392 if (!qs.hasConst() || qs.hasVolatile()) return false;
1394 // Otherwise, all object types satisfy this except C++ classes with
1395 // mutable subobjects or non-trivial copy/destroy behavior.
1396 if (const auto *RT = dyn_cast<RecordType>(type))
1397 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1398 if (RD->hasMutableFields() || !RD->isTrivial())
1404 /// Can we constant-emit a load of a reference to a variable of the
1405 /// given type? This is different from predicates like
1406 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1407 /// in situations that don't necessarily satisfy the language's rules
1408 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1409 /// to do this with const float variables even if those variables
1410 /// aren't marked 'constexpr'.
1411 enum ConstantEmissionKind {
1413 CEK_AsReferenceOnly,
1414 CEK_AsValueOrReference,
1417 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1418 type = type.getCanonicalType();
1419 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1420 if (isConstantEmittableObjectType(ref->getPointeeType()))
1421 return CEK_AsValueOrReference;
1422 return CEK_AsReferenceOnly;
1424 if (isConstantEmittableObjectType(type))
1425 return CEK_AsValueOnly;
1429 /// Try to emit a reference to the given value without producing it as
1430 /// an l-value. This is just an optimization, but it avoids us needing
1431 /// to emit global copies of variables if they're named without triggering
1432 /// a formal use in a context where we can't emit a direct reference to them,
1433 /// for instance if a block or lambda or a member of a local class uses a
1434 /// const int variable or constexpr variable from an enclosing function.
1435 CodeGenFunction::ConstantEmission
1436 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1437 ValueDecl *value = refExpr->getDecl();
1439 // The value needs to be an enum constant or a constant variable.
1440 ConstantEmissionKind CEK;
1441 if (isa<ParmVarDecl>(value)) {
1443 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1444 CEK = checkVarTypeForConstantEmission(var->getType());
1445 } else if (isa<EnumConstantDecl>(value)) {
1446 CEK = CEK_AsValueOnly;
1450 if (CEK == CEK_None) return ConstantEmission();
1452 Expr::EvalResult result;
1453 bool resultIsReference;
1454 QualType resultType;
1456 // It's best to evaluate all the way as an r-value if that's permitted.
1457 if (CEK != CEK_AsReferenceOnly &&
1458 refExpr->EvaluateAsRValue(result, getContext())) {
1459 resultIsReference = false;
1460 resultType = refExpr->getType();
1462 // Otherwise, try to evaluate as an l-value.
1463 } else if (CEK != CEK_AsValueOnly &&
1464 refExpr->EvaluateAsLValue(result, getContext())) {
1465 resultIsReference = true;
1466 resultType = value->getType();
1470 return ConstantEmission();
1473 // In any case, if the initializer has side-effects, abandon ship.
1474 if (result.HasSideEffects)
1475 return ConstantEmission();
1477 // Emit as a constant.
1478 auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1479 result.Val, resultType);
1481 // Make sure we emit a debug reference to the global variable.
1482 // This should probably fire even for
1483 if (isa<VarDecl>(value)) {
1484 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1485 EmitDeclRefExprDbgValue(refExpr, result.Val);
1487 assert(isa<EnumConstantDecl>(value));
1488 EmitDeclRefExprDbgValue(refExpr, result.Val);
1491 // If we emitted a reference constant, we need to dereference that.
1492 if (resultIsReference)
1493 return ConstantEmission::forReference(C);
1495 return ConstantEmission::forValue(C);
1498 static DeclRefExpr *tryToConvertMemberExprToDeclRefExpr(CodeGenFunction &CGF,
1499 const MemberExpr *ME) {
1500 if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1501 // Try to emit static variable member expressions as DREs.
1502 return DeclRefExpr::Create(
1503 CGF.getContext(), NestedNameSpecifierLoc(), SourceLocation(), VD,
1504 /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1505 ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1510 CodeGenFunction::ConstantEmission
1511 CodeGenFunction::tryEmitAsConstant(const MemberExpr *ME) {
1512 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1513 return tryEmitAsConstant(DRE);
1514 return ConstantEmission();
1517 llvm::Value *CodeGenFunction::emitScalarConstant(
1518 const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1519 assert(Constant && "not a constant");
1520 if (Constant.isReference())
1521 return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1524 return Constant.getValue();
1527 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1528 SourceLocation Loc) {
1529 return EmitLoadOfScalar(lvalue.getAddress(*this), lvalue.isVolatile(),
1530 lvalue.getType(), Loc, lvalue.getBaseInfo(),
1531 lvalue.getTBAAInfo(), lvalue.isNontemporal());
1534 static bool hasBooleanRepresentation(QualType Ty) {
1535 if (Ty->isBooleanType())
1538 if (const EnumType *ET = Ty->getAs<EnumType>())
1539 return ET->getDecl()->getIntegerType()->isBooleanType();
1541 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1542 return hasBooleanRepresentation(AT->getValueType());
1547 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1548 llvm::APInt &Min, llvm::APInt &End,
1549 bool StrictEnums, bool IsBool) {
1550 const EnumType *ET = Ty->getAs<EnumType>();
1551 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1552 ET && !ET->getDecl()->isFixed();
1553 if (!IsBool && !IsRegularCPlusPlusEnum)
1557 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1558 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1560 const EnumDecl *ED = ET->getDecl();
1561 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1562 unsigned Bitwidth = LTy->getScalarSizeInBits();
1563 unsigned NumNegativeBits = ED->getNumNegativeBits();
1564 unsigned NumPositiveBits = ED->getNumPositiveBits();
1566 if (NumNegativeBits) {
1567 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1568 assert(NumBits <= Bitwidth);
1569 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1572 assert(NumPositiveBits <= Bitwidth);
1573 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1574 Min = llvm::APInt(Bitwidth, 0);
1580 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1581 llvm::APInt Min, End;
1582 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1583 hasBooleanRepresentation(Ty)))
1586 llvm::MDBuilder MDHelper(getLLVMContext());
1587 return MDHelper.createRange(Min, End);
1590 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1591 SourceLocation Loc) {
1592 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1593 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1594 if (!HasBoolCheck && !HasEnumCheck)
1597 bool IsBool = hasBooleanRepresentation(Ty) ||
1598 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1599 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1600 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1601 if (!NeedsBoolCheck && !NeedsEnumCheck)
1604 // Single-bit booleans don't need to be checked. Special-case this to avoid
1605 // a bit width mismatch when handling bitfield values. This is handled by
1606 // EmitFromMemory for the non-bitfield case.
1608 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1611 llvm::APInt Min, End;
1612 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1615 auto &Ctx = getLLVMContext();
1616 SanitizerScope SanScope(this);
1620 Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1622 llvm::Value *Upper =
1623 Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1624 llvm::Value *Lower =
1625 Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1626 Check = Builder.CreateAnd(Upper, Lower);
1628 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1629 EmitCheckTypeDescriptor(Ty)};
1630 SanitizerMask Kind =
1631 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1632 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1633 StaticArgs, EmitCheckValue(Value));
1637 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1640 LValueBaseInfo BaseInfo,
1641 TBAAAccessInfo TBAAInfo,
1642 bool isNontemporal) {
1643 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1644 // For better performance, handle vector loads differently.
1645 if (Ty->isVectorType()) {
1646 const llvm::Type *EltTy = Addr.getElementType();
1648 const auto *VTy = cast<llvm::VectorType>(EltTy);
1650 // Handle vectors of size 3 like size 4 for better performance.
1651 if (VTy->getNumElements() == 3) {
1653 // Bitcast to vec4 type.
1654 llvm::VectorType *vec4Ty =
1655 llvm::VectorType::get(VTy->getElementType(), 4);
1656 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1658 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1660 // Shuffle vector to get vec3.
1661 V = Builder.CreateShuffleVector(V, llvm::UndefValue::get(vec4Ty),
1662 {0, 1, 2}, "extractVec");
1663 return EmitFromMemory(V, Ty);
1668 // Atomic operations have to be done on integral types.
1669 LValue AtomicLValue =
1670 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1671 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1672 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1675 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1676 if (isNontemporal) {
1677 llvm::MDNode *Node = llvm::MDNode::get(
1678 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1679 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1682 CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
1684 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1685 // In order to prevent the optimizer from throwing away the check, don't
1686 // attach range metadata to the load.
1687 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1688 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1689 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1691 return EmitFromMemory(Load, Ty);
1694 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
1695 // Bool has a different representation in memory than in registers.
1696 if (hasBooleanRepresentation(Ty)) {
1697 // This should really always be an i1, but sometimes it's already
1698 // an i8, and it's awkward to track those cases down.
1699 if (Value->getType()->isIntegerTy(1))
1700 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1701 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1702 "wrong value rep of bool");
1708 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
1709 // Bool has a different representation in memory than in registers.
1710 if (hasBooleanRepresentation(Ty)) {
1711 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1712 "wrong value rep of bool");
1713 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1719 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
1720 bool Volatile, QualType Ty,
1721 LValueBaseInfo BaseInfo,
1722 TBAAAccessInfo TBAAInfo,
1723 bool isInit, bool isNontemporal) {
1724 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1725 // Handle vectors differently to get better performance.
1726 if (Ty->isVectorType()) {
1727 llvm::Type *SrcTy = Value->getType();
1728 auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1729 // Handle vec3 special.
1730 if (VecTy && VecTy->getNumElements() == 3) {
1731 // Our source is a vec3, do a shuffle vector to make it a vec4.
1732 llvm::Constant *Mask[] = {Builder.getInt32(0), Builder.getInt32(1),
1733 Builder.getInt32(2),
1734 llvm::UndefValue::get(Builder.getInt32Ty())};
1735 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1736 Value = Builder.CreateShuffleVector(Value, llvm::UndefValue::get(VecTy),
1737 MaskV, "extractVec");
1738 SrcTy = llvm::VectorType::get(VecTy->getElementType(), 4);
1740 if (Addr.getElementType() != SrcTy) {
1741 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1746 Value = EmitToMemory(Value, Ty);
1748 LValue AtomicLValue =
1749 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1750 if (Ty->isAtomicType() ||
1751 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1752 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1756 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1757 if (isNontemporal) {
1758 llvm::MDNode *Node =
1759 llvm::MDNode::get(Store->getContext(),
1760 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1761 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1764 CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
1767 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
1769 EmitStoreOfScalar(value, lvalue.getAddress(*this), lvalue.isVolatile(),
1770 lvalue.getType(), lvalue.getBaseInfo(),
1771 lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1774 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1775 /// method emits the address of the lvalue, then loads the result as an rvalue,
1776 /// returning the rvalue.
1777 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
1778 if (LV.isObjCWeak()) {
1779 // load of a __weak object.
1780 Address AddrWeakObj = LV.getAddress(*this);
1781 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
1784 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1785 // In MRC mode, we do a load+autorelease.
1786 if (!getLangOpts().ObjCAutoRefCount) {
1787 return RValue::get(EmitARCLoadWeak(LV.getAddress(*this)));
1790 // In ARC mode, we load retained and then consume the value.
1791 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress(*this));
1792 Object = EmitObjCConsumeObject(LV.getType(), Object);
1793 return RValue::get(Object);
1796 if (LV.isSimple()) {
1797 assert(!LV.getType()->isFunctionType());
1799 // Everything needs a load.
1800 return RValue::get(EmitLoadOfScalar(LV, Loc));
1803 if (LV.isVectorElt()) {
1804 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1805 LV.isVolatileQualified());
1806 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1810 // If this is a reference to a subset of the elements of a vector, either
1811 // shuffle the input or extract/insert them as appropriate.
1812 if (LV.isExtVectorElt())
1813 return EmitLoadOfExtVectorElementLValue(LV);
1815 // Global Register variables always invoke intrinsics
1816 if (LV.isGlobalReg())
1817 return EmitLoadOfGlobalRegLValue(LV);
1819 assert(LV.isBitField() && "Unknown LValue type!");
1820 return EmitLoadOfBitfieldLValue(LV, Loc);
1823 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
1824 SourceLocation Loc) {
1825 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1827 // Get the output type.
1828 llvm::Type *ResLTy = ConvertType(LV.getType());
1830 Address Ptr = LV.getBitFieldAddress();
1831 llvm::Value *Val = Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1833 if (Info.IsSigned) {
1834 assert(static_cast<unsigned>(Info.Offset + Info.Size) <= Info.StorageSize);
1835 unsigned HighBits = Info.StorageSize - Info.Offset - Info.Size;
1837 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1838 if (Info.Offset + HighBits)
1839 Val = Builder.CreateAShr(Val, Info.Offset + HighBits, "bf.ashr");
1842 Val = Builder.CreateLShr(Val, Info.Offset, "bf.lshr");
1843 if (static_cast<unsigned>(Info.Offset) + Info.Size < Info.StorageSize)
1844 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(Info.StorageSize,
1848 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1849 EmitScalarRangeCheck(Val, LV.getType(), Loc);
1850 return RValue::get(Val);
1853 // If this is a reference to a subset of the elements of a vector, create an
1854 // appropriate shufflevector.
1855 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
1856 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
1857 LV.isVolatileQualified());
1859 const llvm::Constant *Elts = LV.getExtVectorElts();
1861 // If the result of the expression is a non-vector type, we must be extracting
1862 // a single element. Just codegen as an extractelement.
1863 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1865 unsigned InIdx = getAccessedFieldNo(0, Elts);
1866 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1867 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1870 // Always use shuffle vector to try to retain the original program structure
1871 unsigned NumResultElts = ExprVT->getNumElements();
1873 SmallVector<llvm::Constant*, 4> Mask;
1874 for (unsigned i = 0; i != NumResultElts; ++i)
1875 Mask.push_back(Builder.getInt32(getAccessedFieldNo(i, Elts)));
1877 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
1878 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()),
1880 return RValue::get(Vec);
1883 /// Generates lvalue for partial ext_vector access.
1884 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
1885 Address VectorAddress = LV.getExtVectorAddress();
1886 QualType EQT = LV.getType()->castAs<VectorType>()->getElementType();
1887 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
1889 Address CastToPointerElement =
1890 Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
1891 "conv.ptr.element");
1893 const llvm::Constant *Elts = LV.getExtVectorElts();
1894 unsigned ix = getAccessedFieldNo(0, Elts);
1896 Address VectorBasePtrPlusIx =
1897 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
1900 return VectorBasePtrPlusIx;
1903 /// Load of global gamed gegisters are always calls to intrinsics.
1904 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
1905 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
1906 "Bad type for register variable");
1907 llvm::MDNode *RegName = cast<llvm::MDNode>(
1908 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
1910 // We accept integer and pointer types only
1911 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
1912 llvm::Type *Ty = OrigTy;
1913 if (OrigTy->isPointerTy())
1914 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
1915 llvm::Type *Types[] = { Ty };
1917 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
1918 llvm::Value *Call = Builder.CreateCall(
1919 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
1920 if (OrigTy->isPointerTy())
1921 Call = Builder.CreateIntToPtr(Call, OrigTy);
1922 return RValue::get(Call);
1926 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
1927 /// lvalue, where both are guaranteed to the have the same type, and that type
1929 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
1931 if (!Dst.isSimple()) {
1932 if (Dst.isVectorElt()) {
1933 // Read/modify/write the vector, inserting the new element.
1934 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
1935 Dst.isVolatileQualified());
1936 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
1937 Dst.getVectorIdx(), "vecins");
1938 Builder.CreateStore(Vec, Dst.getVectorAddress(),
1939 Dst.isVolatileQualified());
1943 // If this is an update of extended vector elements, insert them as
1945 if (Dst.isExtVectorElt())
1946 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
1948 if (Dst.isGlobalReg())
1949 return EmitStoreThroughGlobalRegLValue(Src, Dst);
1951 assert(Dst.isBitField() && "Unknown LValue type");
1952 return EmitStoreThroughBitfieldLValue(Src, Dst);
1955 // There's special magic for assigning into an ARC-qualified l-value.
1956 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
1958 case Qualifiers::OCL_None:
1959 llvm_unreachable("present but none");
1961 case Qualifiers::OCL_ExplicitNone:
1965 case Qualifiers::OCL_Strong:
1967 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
1970 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
1973 case Qualifiers::OCL_Weak:
1975 // Initialize and then skip the primitive store.
1976 EmitARCInitWeak(Dst.getAddress(*this), Src.getScalarVal());
1978 EmitARCStoreWeak(Dst.getAddress(*this), Src.getScalarVal(),
1982 case Qualifiers::OCL_Autoreleasing:
1983 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
1984 Src.getScalarVal()));
1985 // fall into the normal path
1990 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
1991 // load of a __weak object.
1992 Address LvalueDst = Dst.getAddress(*this);
1993 llvm::Value *src = Src.getScalarVal();
1994 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
1998 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
1999 // load of a __strong object.
2000 Address LvalueDst = Dst.getAddress(*this);
2001 llvm::Value *src = Src.getScalarVal();
2002 if (Dst.isObjCIvar()) {
2003 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2004 llvm::Type *ResultType = IntPtrTy;
2005 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
2006 llvm::Value *RHS = dst.getPointer();
2007 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2009 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
2010 "sub.ptr.lhs.cast");
2011 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2012 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2014 } else if (Dst.isGlobalObjCRef()) {
2015 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2016 Dst.isThreadLocalRef());
2019 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2023 assert(Src.isScalar() && "Can't emit an agg store with this method");
2024 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2027 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
2028 llvm::Value **Result) {
2029 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2030 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2031 Address Ptr = Dst.getBitFieldAddress();
2033 // Get the source value, truncated to the width of the bit-field.
2034 llvm::Value *SrcVal = Src.getScalarVal();
2036 // Cast the source to the storage type and shift it into place.
2037 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2038 /*isSigned=*/false);
2039 llvm::Value *MaskedVal = SrcVal;
2041 // See if there are other bits in the bitfield's storage we'll need to load
2042 // and mask together with source before storing.
2043 if (Info.StorageSize != Info.Size) {
2044 assert(Info.StorageSize > Info.Size && "Invalid bitfield size.");
2046 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2048 // Mask the source value as needed.
2049 if (!hasBooleanRepresentation(Dst.getType()))
2050 SrcVal = Builder.CreateAnd(SrcVal,
2051 llvm::APInt::getLowBitsSet(Info.StorageSize,
2056 SrcVal = Builder.CreateShl(SrcVal, Info.Offset, "bf.shl");
2058 // Mask out the original value.
2059 Val = Builder.CreateAnd(Val,
2060 ~llvm::APInt::getBitsSet(Info.StorageSize,
2062 Info.Offset + Info.Size),
2065 // Or together the unchanged values and the source value.
2066 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2068 assert(Info.Offset == 0);
2071 // Write the new value back out.
2072 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2074 // Return the new value of the bit-field, if requested.
2076 llvm::Value *ResultVal = MaskedVal;
2078 // Sign extend the value if needed.
2079 if (Info.IsSigned) {
2080 assert(Info.Size <= Info.StorageSize);
2081 unsigned HighBits = Info.StorageSize - Info.Size;
2083 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2084 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2088 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2090 *Result = EmitFromMemory(ResultVal, Dst.getType());
2094 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
2096 // This access turns into a read/modify/write of the vector. Load the input
2098 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(),
2099 Dst.isVolatileQualified());
2100 const llvm::Constant *Elts = Dst.getExtVectorElts();
2102 llvm::Value *SrcVal = Src.getScalarVal();
2104 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2105 unsigned NumSrcElts = VTy->getNumElements();
2106 unsigned NumDstElts = Vec->getType()->getVectorNumElements();
2107 if (NumDstElts == NumSrcElts) {
2108 // Use shuffle vector is the src and destination are the same number of
2109 // elements and restore the vector mask since it is on the side it will be
2111 SmallVector<llvm::Constant*, 4> Mask(NumDstElts);
2112 for (unsigned i = 0; i != NumSrcElts; ++i)
2113 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i);
2115 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2116 Vec = Builder.CreateShuffleVector(SrcVal,
2117 llvm::UndefValue::get(Vec->getType()),
2119 } else if (NumDstElts > NumSrcElts) {
2120 // Extended the source vector to the same length and then shuffle it
2121 // into the destination.
2122 // FIXME: since we're shuffling with undef, can we just use the indices
2123 // into that? This could be simpler.
2124 SmallVector<llvm::Constant*, 4> ExtMask;
2125 for (unsigned i = 0; i != NumSrcElts; ++i)
2126 ExtMask.push_back(Builder.getInt32(i));
2127 ExtMask.resize(NumDstElts, llvm::UndefValue::get(Int32Ty));
2128 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask);
2129 llvm::Value *ExtSrcVal =
2130 Builder.CreateShuffleVector(SrcVal,
2131 llvm::UndefValue::get(SrcVal->getType()),
2134 SmallVector<llvm::Constant*, 4> Mask;
2135 for (unsigned i = 0; i != NumDstElts; ++i)
2136 Mask.push_back(Builder.getInt32(i));
2138 // When the vector size is odd and .odd or .hi is used, the last element
2139 // of the Elts constant array will be one past the size of the vector.
2140 // Ignore the last element here, if it is greater than the mask size.
2141 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2144 // modify when what gets shuffled in
2145 for (unsigned i = 0; i != NumSrcElts; ++i)
2146 Mask[getAccessedFieldNo(i, Elts)] = Builder.getInt32(i+NumDstElts);
2147 llvm::Value *MaskV = llvm::ConstantVector::get(Mask);
2148 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV);
2150 // We should never shorten the vector
2151 llvm_unreachable("unexpected shorten vector length");
2154 // If the Src is a scalar (not a vector) it must be updating one element.
2155 unsigned InIdx = getAccessedFieldNo(0, Elts);
2156 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2157 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2160 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
2161 Dst.isVolatileQualified());
2164 /// Store of global named registers are always calls to intrinsics.
2165 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
2166 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2167 "Bad type for register variable");
2168 llvm::MDNode *RegName = cast<llvm::MDNode>(
2169 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2170 assert(RegName && "Register LValue is not metadata");
2172 // We accept integer and pointer types only
2173 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2174 llvm::Type *Ty = OrigTy;
2175 if (OrigTy->isPointerTy())
2176 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2177 llvm::Type *Types[] = { Ty };
2179 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2180 llvm::Value *Value = Src.getScalarVal();
2181 if (OrigTy->isPointerTy())
2182 Value = Builder.CreatePtrToInt(Value, Ty);
2184 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2187 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2188 // generating write-barries API. It is currently a global, ivar,
2190 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2192 bool IsMemberAccess=false) {
2193 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2196 if (isa<ObjCIvarRefExpr>(E)) {
2197 QualType ExpTy = E->getType();
2198 if (IsMemberAccess && ExpTy->isPointerType()) {
2199 // If ivar is a structure pointer, assigning to field of
2200 // this struct follows gcc's behavior and makes it a non-ivar
2201 // writer-barrier conservatively.
2202 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2203 if (ExpTy->isRecordType()) {
2204 LV.setObjCIvar(false);
2208 LV.setObjCIvar(true);
2209 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2210 LV.setBaseIvarExp(Exp->getBase());
2211 LV.setObjCArray(E->getType()->isArrayType());
2215 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2216 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2217 if (VD->hasGlobalStorage()) {
2218 LV.setGlobalObjCRef(true);
2219 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2222 LV.setObjCArray(E->getType()->isArrayType());
2226 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2227 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2231 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2232 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2233 if (LV.isObjCIvar()) {
2234 // If cast is to a structure pointer, follow gcc's behavior and make it
2235 // a non-ivar write-barrier.
2236 QualType ExpTy = E->getType();
2237 if (ExpTy->isPointerType())
2238 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2239 if (ExpTy->isRecordType())
2240 LV.setObjCIvar(false);
2245 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2246 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2250 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2251 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2255 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2256 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2260 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2261 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2265 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2266 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2267 if (LV.isObjCIvar() && !LV.isObjCArray())
2268 // Using array syntax to assigning to what an ivar points to is not
2269 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2270 LV.setObjCIvar(false);
2271 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2272 // Using array syntax to assigning to what global points to is not
2273 // same as assigning to the global itself. {id *G;} G[i] = 0;
2274 LV.setGlobalObjCRef(false);
2278 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2279 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2280 // We don't know if member is an 'ivar', but this flag is looked at
2281 // only in the context of LV.isObjCIvar().
2282 LV.setObjCArray(E->getType()->isArrayType());
2287 static llvm::Value *
2288 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF,
2289 llvm::Value *V, llvm::Type *IRType,
2290 StringRef Name = StringRef()) {
2291 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2292 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2295 static LValue EmitThreadPrivateVarDeclLValue(
2296 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2297 llvm::Type *RealVarTy, SourceLocation Loc) {
2298 Addr = CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2299 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2300 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2303 static Address emitDeclTargetVarDeclLValue(CodeGenFunction &CGF,
2304 const VarDecl *VD, QualType T) {
2305 llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2306 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2307 // Return an invalid address if variable is MT_To and unified
2308 // memory is not enabled. For all other cases: MT_Link and
2309 // MT_To with unified memory, return a valid address.
2310 if (!Res || (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2311 !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory()))
2312 return Address::invalid();
2313 assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2314 (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2315 CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) &&
2316 "Expected link clause OR to clause with unified memory enabled.");
2317 QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2318 Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2319 return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2323 CodeGenFunction::EmitLoadOfReference(LValue RefLVal,
2324 LValueBaseInfo *PointeeBaseInfo,
2325 TBAAAccessInfo *PointeeTBAAInfo) {
2326 llvm::LoadInst *Load =
2327 Builder.CreateLoad(RefLVal.getAddress(*this), RefLVal.isVolatile());
2328 CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2330 CharUnits Align = getNaturalTypeAlignment(RefLVal.getType()->getPointeeType(),
2331 PointeeBaseInfo, PointeeTBAAInfo,
2332 /* forPointeeType= */ true);
2333 return Address(Load, Align);
2336 LValue CodeGenFunction::EmitLoadOfReferenceLValue(LValue RefLVal) {
2337 LValueBaseInfo PointeeBaseInfo;
2338 TBAAAccessInfo PointeeTBAAInfo;
2339 Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2341 return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2342 PointeeBaseInfo, PointeeTBAAInfo);
2345 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2346 const PointerType *PtrTy,
2347 LValueBaseInfo *BaseInfo,
2348 TBAAAccessInfo *TBAAInfo) {
2349 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2350 return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(),
2352 /*forPointeeType=*/true));
2355 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2356 const PointerType *PtrTy) {
2357 LValueBaseInfo BaseInfo;
2358 TBAAAccessInfo TBAAInfo;
2359 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2360 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2363 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2364 const Expr *E, const VarDecl *VD) {
2365 QualType T = E->getType();
2367 // If it's thread_local, emit a call to its wrapper function instead.
2368 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2369 CGF.CGM.getCXXABI().usesThreadWrapperFunction(VD))
2370 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2371 // Check if the variable is marked as declare target with link clause in
2373 if (CGF.getLangOpts().OpenMPIsDevice) {
2374 Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2376 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2379 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2380 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2381 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2382 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2383 Address Addr(V, Alignment);
2384 // Emit reference to the private copy of the variable if it is an OpenMP
2385 // threadprivate variable.
2386 if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2387 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2388 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2391 LValue LV = VD->getType()->isReferenceType() ?
2392 CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2393 AlignmentSource::Decl) :
2394 CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2395 setObjCGCLValueClass(CGF.getContext(), E, LV);
2399 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2400 const FunctionDecl *FD) {
2401 if (FD->hasAttr<WeakRefAttr>()) {
2402 ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2403 return aliasee.getPointer();
2406 llvm::Constant *V = CGM.GetAddrOfFunction(FD);
2407 if (!FD->hasPrototype()) {
2408 if (const FunctionProtoType *Proto =
2409 FD->getType()->getAs<FunctionProtoType>()) {
2410 // Ugly case: for a K&R-style definition, the type of the definition
2411 // isn't the same as the type of a use. Correct for this with a
2413 QualType NoProtoType =
2414 CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2415 NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2416 V = llvm::ConstantExpr::getBitCast(V,
2417 CGM.getTypes().ConvertType(NoProtoType));
2423 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
2424 const Expr *E, const FunctionDecl *FD) {
2425 llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
2426 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2427 return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2428 AlignmentSource::Decl);
2431 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2432 llvm::Value *ThisValue) {
2433 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());
2434 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2435 return CGF.EmitLValueForField(LV, FD);
2438 /// Named Registers are named metadata pointing to the register name
2439 /// which will be read from/written to as an argument to the intrinsic
2440 /// @llvm.read/write_register.
2441 /// So far, only the name is being passed down, but other options such as
2442 /// register type, allocation type or even optimization options could be
2443 /// passed down via the metadata node.
2444 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2445 SmallString<64> Name("llvm.named.register.");
2446 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2447 assert(Asm->getLabel().size() < 64-Name.size() &&
2448 "Register name too big");
2449 Name.append(Asm->getLabel());
2450 llvm::NamedMDNode *M =
2451 CGM.getModule().getOrInsertNamedMetadata(Name);
2452 if (M->getNumOperands() == 0) {
2453 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2455 llvm::Metadata *Ops[] = {Str};
2456 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2459 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2462 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2463 return LValue::MakeGlobalReg(Address(Ptr, Alignment), VD->getType());
2466 /// Determine whether we can emit a reference to \p VD from the current
2467 /// context, despite not necessarily having seen an odr-use of the variable in
2469 static bool canEmitSpuriousReferenceToVariable(CodeGenFunction &CGF,
2470 const DeclRefExpr *E,
2473 // For a variable declared in an enclosing scope, do not emit a spurious
2474 // reference even if we have a capture, as that will emit an unwarranted
2475 // reference to our capture state, and will likely generate worse code than
2476 // emitting a local copy.
2477 if (E->refersToEnclosingVariableOrCapture())
2480 // For a local declaration declared in this function, we can always reference
2481 // it even if we don't have an odr-use.
2482 if (VD->hasLocalStorage()) {
2483 return VD->getDeclContext() ==
2484 dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2487 // For a global declaration, we can emit a reference to it if we know
2488 // for sure that we are able to emit a definition of it.
2489 VD = VD->getDefinition(CGF.getContext());
2493 // Don't emit a spurious reference if it might be to a variable that only
2494 // exists on a different device / target.
2495 // FIXME: This is unnecessarily broad. Check whether this would actually be a
2496 // cross-target reference.
2497 if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2498 CGF.getLangOpts().OpenCL) {
2502 // We can emit a spurious reference only if the linkage implies that we'll
2503 // be emitting a non-interposable symbol that will be retained until link
2505 switch (CGF.CGM.getLLVMLinkageVarDefinition(VD, IsConstant)) {
2506 case llvm::GlobalValue::ExternalLinkage:
2507 case llvm::GlobalValue::LinkOnceODRLinkage:
2508 case llvm::GlobalValue::WeakODRLinkage:
2509 case llvm::GlobalValue::InternalLinkage:
2510 case llvm::GlobalValue::PrivateLinkage:
2517 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2518 const NamedDecl *ND = E->getDecl();
2519 QualType T = E->getType();
2521 assert(E->isNonOdrUse() != NOUR_Unevaluated &&
2522 "should not emit an unevaluated operand");
2524 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2525 // Global Named registers access via intrinsics only
2526 if (VD->getStorageClass() == SC_Register &&
2527 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2528 return EmitGlobalNamedRegister(VD, CGM);
2530 // If this DeclRefExpr does not constitute an odr-use of the variable,
2531 // we're not permitted to emit a reference to it in general, and it might
2532 // not be captured if capture would be necessary for a use. Emit the
2533 // constant value directly instead.
2534 if (E->isNonOdrUse() == NOUR_Constant &&
2535 (VD->getType()->isReferenceType() ||
2536 !canEmitSpuriousReferenceToVariable(*this, E, VD, true))) {
2537 VD->getAnyInitializer(VD);
2538 llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
2539 E->getLocation(), *VD->evaluateValue(), VD->getType());
2540 assert(Val && "failed to emit constant expression");
2542 Address Addr = Address::invalid();
2543 if (!VD->getType()->isReferenceType()) {
2544 // Spill the constant value to a global.
2545 Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
2546 getContext().getDeclAlign(VD));
2547 llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
2548 auto *PTy = llvm::PointerType::get(
2549 VarTy, getContext().getTargetAddressSpace(VD->getType()));
2550 if (PTy != Addr.getType())
2551 Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy);
2553 // Should we be using the alignment of the constant pointer we emitted?
2554 CharUnits Alignment =
2555 getNaturalTypeAlignment(E->getType(),
2556 /* BaseInfo= */ nullptr,
2557 /* TBAAInfo= */ nullptr,
2558 /* forPointeeType= */ true);
2559 Addr = Address(Val, Alignment);
2561 return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2564 // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
2566 // Check for captured variables.
2567 if (E->refersToEnclosingVariableOrCapture()) {
2568 VD = VD->getCanonicalDecl();
2569 if (auto *FD = LambdaCaptureFields.lookup(VD))
2570 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2571 if (CapturedStmtInfo) {
2572 auto I = LocalDeclMap.find(VD);
2573 if (I != LocalDeclMap.end()) {
2575 if (VD->getType()->isReferenceType())
2576 CapLVal = EmitLoadOfReferenceLValue(I->second, VD->getType(),
2577 AlignmentSource::Decl);
2579 CapLVal = MakeAddrLValue(I->second, T);
2580 // Mark lvalue as nontemporal if the variable is marked as nontemporal
2582 if (getLangOpts().OpenMP &&
2583 CGM.getOpenMPRuntime().isNontemporalDecl(VD))
2584 CapLVal.setNontemporal(/*Value=*/true);
2588 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
2589 CapturedStmtInfo->getContextValue());
2590 CapLVal = MakeAddrLValue(
2591 Address(CapLVal.getPointer(*this), getContext().getDeclAlign(VD)),
2592 CapLVal.getType(), LValueBaseInfo(AlignmentSource::Decl),
2593 CapLVal.getTBAAInfo());
2594 // Mark lvalue as nontemporal if the variable is marked as nontemporal
2596 if (getLangOpts().OpenMP &&
2597 CGM.getOpenMPRuntime().isNontemporalDecl(VD))
2598 CapLVal.setNontemporal(/*Value=*/true);
2602 assert(isa<BlockDecl>(CurCodeDecl));
2603 Address addr = GetAddrOfBlockDecl(VD);
2604 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2608 // FIXME: We should be able to assert this for FunctionDecls as well!
2609 // FIXME: We should be able to assert this for all DeclRefExprs, not just
2610 // those with a valid source location.
2611 assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
2612 !E->getLocation().isValid()) &&
2613 "Should not use decl without marking it used!");
2615 if (ND->hasAttr<WeakRefAttr>()) {
2616 const auto *VD = cast<ValueDecl>(ND);
2617 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2618 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2621 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2622 // Check if this is a global variable.
2623 if (VD->hasLinkage() || VD->isStaticDataMember())
2624 return EmitGlobalVarDeclLValue(*this, E, VD);
2626 Address addr = Address::invalid();
2628 // The variable should generally be present in the local decl map.
2629 auto iter = LocalDeclMap.find(VD);
2630 if (iter != LocalDeclMap.end()) {
2631 addr = iter->second;
2633 // Otherwise, it might be static local we haven't emitted yet for
2634 // some reason; most likely, because it's in an outer function.
2635 } else if (VD->isStaticLocal()) {
2636 addr = Address(CGM.getOrCreateStaticVarDecl(
2637 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false)),
2638 getContext().getDeclAlign(VD));
2640 // No other cases for now.
2642 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2646 // Check for OpenMP threadprivate variables.
2647 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2648 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2649 return EmitThreadPrivateVarDeclLValue(
2650 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2654 // Drill into block byref variables.
2655 bool isBlockByref = VD->isEscapingByref();
2657 addr = emitBlockByrefAddress(addr, VD);
2660 // Drill into reference types.
2661 LValue LV = VD->getType()->isReferenceType() ?
2662 EmitLoadOfReferenceLValue(addr, VD->getType(), AlignmentSource::Decl) :
2663 MakeAddrLValue(addr, T, AlignmentSource::Decl);
2665 bool isLocalStorage = VD->hasLocalStorage();
2667 bool NonGCable = isLocalStorage &&
2668 !VD->getType()->isReferenceType() &&
2671 LV.getQuals().removeObjCGCAttr();
2675 bool isImpreciseLifetime =
2676 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2677 if (isImpreciseLifetime)
2678 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
2679 setObjCGCLValueClass(getContext(), E, LV);
2683 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
2684 return EmitFunctionDeclLValue(*this, E, FD);
2686 // FIXME: While we're emitting a binding from an enclosing scope, all other
2687 // DeclRefExprs we see should be implicitly treated as if they also refer to
2688 // an enclosing scope.
2689 if (const auto *BD = dyn_cast<BindingDecl>(ND))
2690 return EmitLValue(BD->getBinding());
2692 llvm_unreachable("Unhandled DeclRefExpr");
2695 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
2696 // __extension__ doesn't affect lvalue-ness.
2697 if (E->getOpcode() == UO_Extension)
2698 return EmitLValue(E->getSubExpr());
2700 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
2701 switch (E->getOpcode()) {
2702 default: llvm_unreachable("Unknown unary operator lvalue!");
2704 QualType T = E->getSubExpr()->getType()->getPointeeType();
2705 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2707 LValueBaseInfo BaseInfo;
2708 TBAAAccessInfo TBAAInfo;
2709 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2711 LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2712 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2714 // We should not generate __weak write barrier on indirect reference
2715 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2716 // But, we continue to generate __strong write barrier on indirect write
2717 // into a pointer to object.
2718 if (getLangOpts().ObjC &&
2719 getLangOpts().getGC() != LangOptions::NonGC &&
2721 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
2726 LValue LV = EmitLValue(E->getSubExpr());
2727 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2729 // __real is valid on scalars. This is a faster way of testing that.
2730 // __imag can only produce an rvalue on scalars.
2731 if (E->getOpcode() == UO_Real &&
2732 !LV.getAddress(*this).getElementType()->isStructTy()) {
2733 assert(E->getSubExpr()->getType()->isArithmeticType());
2737 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2740 (E->getOpcode() == UO_Real
2741 ? emitAddrOfRealComponent(LV.getAddress(*this), LV.getType())
2742 : emitAddrOfImagComponent(LV.getAddress(*this), LV.getType()));
2743 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2744 CGM.getTBAAInfoForSubobject(LV, T));
2745 ElemLV.getQuals().addQualifiers(LV.getQuals());
2750 LValue LV = EmitLValue(E->getSubExpr());
2751 bool isInc = E->getOpcode() == UO_PreInc;
2753 if (E->getType()->isAnyComplexType())
2754 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2756 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2762 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
2763 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
2764 E->getType(), AlignmentSource::Decl);
2767 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
2768 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
2769 E->getType(), AlignmentSource::Decl);
2772 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
2773 auto SL = E->getFunctionName();
2774 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2775 StringRef FnName = CurFn->getName();
2776 if (FnName.startswith("\01"))
2777 FnName = FnName.substr(1);
2778 StringRef NameItems[] = {
2779 PredefinedExpr::getIdentKindName(E->getIdentKind()), FnName};
2780 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2781 if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2782 std::string Name = SL->getString();
2783 if (!Name.empty()) {
2784 unsigned Discriminator =
2785 CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2787 Name += "_" + Twine(Discriminator + 1).str();
2788 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2789 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2791 auto C = CGM.GetAddrOfConstantCString(FnName, GVName.c_str());
2792 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2795 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2796 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2799 /// Emit a type description suitable for use by a runtime sanitizer library. The
2800 /// format of a type descriptor is
2803 /// { i16 TypeKind, i16 TypeInfo }
2806 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2807 /// integer, 1 for a floating point value, and -1 for anything else.
2808 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
2809 // Only emit each type's descriptor once.
2810 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2813 uint16_t TypeKind = -1;
2814 uint16_t TypeInfo = 0;
2816 if (T->isIntegerType()) {
2818 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2819 (T->isSignedIntegerType() ? 1 : 0);
2820 } else if (T->isFloatingType()) {
2822 TypeInfo = getContext().getTypeSize(T);
2825 // Format the type name as if for a diagnostic, including quotes and
2826 // optionally an 'aka'.
2827 SmallString<32> Buffer;
2828 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
2829 (intptr_t)T.getAsOpaquePtr(),
2830 StringRef(), StringRef(), None, Buffer,
2833 llvm::Constant *Components[] = {
2834 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
2835 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
2837 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
2839 auto *GV = new llvm::GlobalVariable(
2840 CGM.getModule(), Descriptor->getType(),
2841 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
2842 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
2843 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
2845 // Remember the descriptor for this type.
2846 CGM.setTypeDescriptorInMap(T, GV);
2851 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
2852 llvm::Type *TargetTy = IntPtrTy;
2854 if (V->getType() == TargetTy)
2857 // Floating-point types which fit into intptr_t are bitcast to integers
2858 // and then passed directly (after zero-extension, if necessary).
2859 if (V->getType()->isFloatingPointTy()) {
2860 unsigned Bits = V->getType()->getPrimitiveSizeInBits();
2861 if (Bits <= TargetTy->getIntegerBitWidth())
2862 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
2866 // Integers which fit in intptr_t are zero-extended and passed directly.
2867 if (V->getType()->isIntegerTy() &&
2868 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
2869 return Builder.CreateZExt(V, TargetTy);
2871 // Pointers are passed directly, everything else is passed by address.
2872 if (!V->getType()->isPointerTy()) {
2873 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
2874 Builder.CreateStore(V, Ptr);
2875 V = Ptr.getPointer();
2877 return Builder.CreatePtrToInt(V, TargetTy);
2880 /// Emit a representation of a SourceLocation for passing to a handler
2881 /// in a sanitizer runtime library. The format for this data is:
2883 /// struct SourceLocation {
2884 /// const char *Filename;
2885 /// int32_t Line, Column;
2888 /// For an invalid SourceLocation, the Filename pointer is null.
2889 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
2890 llvm::Constant *Filename;
2893 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
2894 if (PLoc.isValid()) {
2895 StringRef FilenameString = PLoc.getFilename();
2897 int PathComponentsToStrip =
2898 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
2899 if (PathComponentsToStrip < 0) {
2900 assert(PathComponentsToStrip != INT_MIN);
2901 int PathComponentsToKeep = -PathComponentsToStrip;
2902 auto I = llvm::sys::path::rbegin(FilenameString);
2903 auto E = llvm::sys::path::rend(FilenameString);
2904 while (I != E && --PathComponentsToKeep)
2907 FilenameString = FilenameString.substr(I - E);
2908 } else if (PathComponentsToStrip > 0) {
2909 auto I = llvm::sys::path::begin(FilenameString);
2910 auto E = llvm::sys::path::end(FilenameString);
2911 while (I != E && PathComponentsToStrip--)
2916 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
2918 FilenameString = llvm::sys::path::filename(FilenameString);
2921 auto FilenameGV = CGM.GetAddrOfConstantCString(FilenameString, ".src");
2922 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
2923 cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
2924 Filename = FilenameGV.getPointer();
2925 Line = PLoc.getLine();
2926 Column = PLoc.getColumn();
2928 Filename = llvm::Constant::getNullValue(Int8PtrTy);
2932 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
2933 Builder.getInt32(Column)};
2935 return llvm::ConstantStruct::getAnon(Data);
2939 /// Specify under what conditions this check can be recovered
2940 enum class CheckRecoverableKind {
2941 /// Always terminate program execution if this check fails.
2943 /// Check supports recovering, runtime has both fatal (noreturn) and
2944 /// non-fatal handlers for this check.
2946 /// Runtime conditionally aborts, always need to support recovery.
2951 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
2952 assert(Kind.countPopulation() == 1);
2953 if (Kind == SanitizerKind::Function || Kind == SanitizerKind::Vptr)
2954 return CheckRecoverableKind::AlwaysRecoverable;
2955 else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
2956 return CheckRecoverableKind::Unrecoverable;
2958 return CheckRecoverableKind::Recoverable;
2962 struct SanitizerHandlerInfo {
2963 char const *const Name;
2968 const SanitizerHandlerInfo SanitizerHandlers[] = {
2969 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
2970 LIST_SANITIZER_CHECKS
2971 #undef SANITIZER_CHECK
2974 static void emitCheckHandlerCall(CodeGenFunction &CGF,
2975 llvm::FunctionType *FnType,
2976 ArrayRef<llvm::Value *> FnArgs,
2977 SanitizerHandler CheckHandler,
2978 CheckRecoverableKind RecoverKind, bool IsFatal,
2979 llvm::BasicBlock *ContBB) {
2980 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
2981 Optional<ApplyDebugLocation> DL;
2982 if (!CGF.Builder.getCurrentDebugLocation()) {
2983 // Ensure that the call has at least an artificial debug location.
2984 DL.emplace(CGF, SourceLocation());
2986 bool NeedsAbortSuffix =
2987 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
2988 bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
2989 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
2990 const StringRef CheckName = CheckInfo.Name;
2991 std::string FnName = "__ubsan_handle_" + CheckName.str();
2992 if (CheckInfo.Version && !MinimalRuntime)
2993 FnName += "_v" + llvm::utostr(CheckInfo.Version);
2995 FnName += "_minimal";
2996 if (NeedsAbortSuffix)
2999 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
3001 llvm::AttrBuilder B;
3003 B.addAttribute(llvm::Attribute::NoReturn)
3004 .addAttribute(llvm::Attribute::NoUnwind);
3006 B.addAttribute(llvm::Attribute::UWTable);
3008 llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
3010 llvm::AttributeList::get(CGF.getLLVMContext(),
3011 llvm::AttributeList::FunctionIndex, B),
3013 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
3015 HandlerCall->setDoesNotReturn();
3016 CGF.Builder.CreateUnreachable();
3018 CGF.Builder.CreateBr(ContBB);
3022 void CodeGenFunction::EmitCheck(
3023 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3024 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3025 ArrayRef<llvm::Value *> DynamicArgs) {
3026 assert(IsSanitizerScope);
3027 assert(Checked.size() > 0);
3028 assert(CheckHandler >= 0 &&
3029 size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
3030 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3032 llvm::Value *FatalCond = nullptr;
3033 llvm::Value *RecoverableCond = nullptr;
3034 llvm::Value *TrapCond = nullptr;
3035 for (int i = 0, n = Checked.size(); i < n; ++i) {
3036 llvm::Value *Check = Checked[i].first;
3037 // -fsanitize-trap= overrides -fsanitize-recover=.
3038 llvm::Value *&Cond =
3039 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3041 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3044 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3048 EmitTrapCheck(TrapCond);
3049 if (!FatalCond && !RecoverableCond)
3052 llvm::Value *JointCond;
3053 if (FatalCond && RecoverableCond)
3054 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3056 JointCond = FatalCond ? FatalCond : RecoverableCond;
3059 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3060 assert(SanOpts.has(Checked[0].second));
3062 for (int i = 1, n = Checked.size(); i < n; ++i) {
3063 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3064 "All recoverable kinds in a single check must be same!");
3065 assert(SanOpts.has(Checked[i].second));
3069 llvm::BasicBlock *Cont = createBasicBlock("cont");
3070 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3071 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3072 // Give hint that we very much don't expect to execute the handler
3073 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
3074 llvm::MDBuilder MDHelper(getLLVMContext());
3075 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3076 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3077 EmitBlock(Handlers);
3079 // Handler functions take an i8* pointing to the (handler-specific) static
3080 // information block, followed by a sequence of intptr_t arguments
3081 // representing operand values.
3082 SmallVector<llvm::Value *, 4> Args;
3083 SmallVector<llvm::Type *, 4> ArgTypes;
3084 if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3085 Args.reserve(DynamicArgs.size() + 1);
3086 ArgTypes.reserve(DynamicArgs.size() + 1);
3088 // Emit handler arguments and create handler function type.
3089 if (!StaticArgs.empty()) {
3090 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3092 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3093 llvm::GlobalVariable::PrivateLinkage, Info);
3094 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3095 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3096 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
3097 ArgTypes.push_back(Int8PtrTy);
3100 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3101 Args.push_back(EmitCheckValue(DynamicArgs[i]));
3102 ArgTypes.push_back(IntPtrTy);
3106 llvm::FunctionType *FnType =
3107 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3109 if (!FatalCond || !RecoverableCond) {
3110 // Simple case: we need to generate a single handler call, either
3111 // fatal, or non-fatal.
3112 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3113 (FatalCond != nullptr), Cont);
3115 // Emit two handler calls: first one for set of unrecoverable checks,
3116 // another one for recoverable.
3117 llvm::BasicBlock *NonFatalHandlerBB =
3118 createBasicBlock("non_fatal." + CheckName);
3119 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3120 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3121 EmitBlock(FatalHandlerBB);
3122 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3124 EmitBlock(NonFatalHandlerBB);
3125 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3132 void CodeGenFunction::EmitCfiSlowPathCheck(
3133 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3134 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3135 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3137 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3138 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3140 llvm::MDBuilder MDHelper(getLLVMContext());
3141 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3142 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3146 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3148 llvm::CallInst *CheckCall;
3149 llvm::FunctionCallee SlowPathFn;
3151 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3153 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3154 llvm::GlobalVariable::PrivateLinkage, Info);
3155 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3156 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3158 SlowPathFn = CGM.getModule().getOrInsertFunction(
3159 "__cfi_slowpath_diag",
3160 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3162 CheckCall = Builder.CreateCall(
3163 SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3165 SlowPathFn = CGM.getModule().getOrInsertFunction(
3167 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3168 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3172 cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3173 CheckCall->setDoesNotThrow();
3178 // Emit a stub for __cfi_check function so that the linker knows about this
3179 // symbol in LTO mode.
3180 void CodeGenFunction::EmitCfiCheckStub() {
3181 llvm::Module *M = &CGM.getModule();
3182 auto &Ctx = M->getContext();
3183 llvm::Function *F = llvm::Function::Create(
3184 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3185 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3187 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3188 // FIXME: consider emitting an intrinsic call like
3189 // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3190 // which can be lowered in CrossDSOCFI pass to the actual contents of
3191 // __cfi_check. This would allow inlining of __cfi_check calls.
3192 llvm::CallInst::Create(
3193 llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3194 llvm::ReturnInst::Create(Ctx, nullptr, BB);
3197 // This function is basically a switch over the CFI failure kind, which is
3198 // extracted from CFICheckFailData (1st function argument). Each case is either
3199 // llvm.trap or a call to one of the two runtime handlers, based on
3200 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3201 // failure kind) traps, but this should really never happen. CFICheckFailData
3202 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3203 // check kind; in this case __cfi_check_fail traps as well.
3204 void CodeGenFunction::EmitCfiCheckFail() {
3205 SanitizerScope SanScope(this);
3206 FunctionArgList Args;
3207 ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy,
3208 ImplicitParamDecl::Other);
3209 ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy,
3210 ImplicitParamDecl::Other);
3211 Args.push_back(&ArgData);
3212 Args.push_back(&ArgAddr);
3214 const CGFunctionInfo &FI =
3215 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
3217 llvm::Function *F = llvm::Function::Create(
3218 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3219 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3221 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F);
3222 CGM.SetLLVMFunctionAttributesForDefinition(nullptr, F);
3223 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3225 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3228 // This function should not be affected by blacklist. This function does
3229 // not have a source location, but "src:*" would still apply. Revert any
3230 // changes to SanOpts made in StartFunction.
3231 SanOpts = CGM.getLangOpts().Sanitize;
3234 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3235 CGM.getContext().VoidPtrTy, ArgData.getLocation());
3237 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3238 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3240 // Data == nullptr means the calling module has trap behaviour for this check.
3241 llvm::Value *DataIsNotNullPtr =
3242 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3243 EmitTrapCheck(DataIsNotNullPtr);
3245 llvm::StructType *SourceLocationTy =
3246 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3247 llvm::StructType *CfiCheckFailDataTy =
3248 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3250 llvm::Value *V = Builder.CreateConstGEP2_32(
3252 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3254 Address CheckKindAddr(V, getIntAlign());
3255 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3257 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3258 CGM.getLLVMContext(),
3259 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3260 llvm::Value *ValidVtable = Builder.CreateZExt(
3261 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3262 {Addr, AllVtables}),
3265 const std::pair<int, SanitizerMask> CheckKinds[] = {
3266 {CFITCK_VCall, SanitizerKind::CFIVCall},
3267 {CFITCK_NVCall, SanitizerKind::CFINVCall},
3268 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3269 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3270 {CFITCK_ICall, SanitizerKind::CFIICall}};
3272 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
3273 for (auto CheckKindMaskPair : CheckKinds) {
3274 int Kind = CheckKindMaskPair.first;
3275 SanitizerMask Mask = CheckKindMaskPair.second;
3277 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3278 if (CGM.getLangOpts().Sanitize.has(Mask))
3279 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3280 {Data, Addr, ValidVtable});
3282 EmitTrapCheck(Cond);
3286 // The only reference to this function will be created during LTO link.
3287 // Make sure it survives until then.
3288 CGM.addUsedGlobal(F);
3291 void CodeGenFunction::EmitUnreachable(SourceLocation Loc) {
3292 if (SanOpts.has(SanitizerKind::Unreachable)) {
3293 SanitizerScope SanScope(this);
3294 EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3295 SanitizerKind::Unreachable),
3296 SanitizerHandler::BuiltinUnreachable,
3297 EmitCheckSourceLocation(Loc), None);
3299 Builder.CreateUnreachable();
3302 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked) {
3303 llvm::BasicBlock *Cont = createBasicBlock("cont");
3305 // If we're optimizing, collapse all calls to trap down to just one per
3306 // function to save on code size.
3307 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3308 TrapBB = createBasicBlock("trap");
3309 Builder.CreateCondBr(Checked, Cont, TrapBB);
3311 llvm::CallInst *TrapCall = EmitTrapCall(llvm::Intrinsic::trap);
3312 TrapCall->setDoesNotReturn();
3313 TrapCall->setDoesNotThrow();
3314 Builder.CreateUnreachable();
3316 Builder.CreateCondBr(Checked, Cont, TrapBB);
3322 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
3323 llvm::CallInst *TrapCall = Builder.CreateCall(CGM.getIntrinsic(IntrID));
3325 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3326 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3327 CGM.getCodeGenOpts().TrapFuncName);
3328 TrapCall->addAttribute(llvm::AttributeList::FunctionIndex, A);
3334 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
3335 LValueBaseInfo *BaseInfo,
3336 TBAAAccessInfo *TBAAInfo) {
3337 assert(E->getType()->isArrayType() &&
3338 "Array to pointer decay must have array source type!");
3340 // Expressions of array type can't be bitfields or vector elements.
3341 LValue LV = EmitLValue(E);
3342 Address Addr = LV.getAddress(*this);
3344 // If the array type was an incomplete type, we need to make sure
3345 // the decay ends up being the right type.
3346 llvm::Type *NewTy = ConvertType(E->getType());
3347 Addr = Builder.CreateElementBitCast(Addr, NewTy);
3349 // Note that VLA pointers are always decayed, so we don't need to do
3351 if (!E->getType()->isVariableArrayType()) {
3352 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3353 "Expected pointer to array");
3354 Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3357 // The result of this decay conversion points to an array element within the
3358 // base lvalue. However, since TBAA currently does not support representing
3359 // accesses to elements of member arrays, we conservatively represent accesses
3360 // to the pointee object as if it had no any base lvalue specified.
3361 // TODO: Support TBAA for member arrays.
3362 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
3363 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3364 if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3366 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3369 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3370 /// array to pointer, return the array subexpression.
3371 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3372 // If this isn't just an array->pointer decay, bail out.
3373 const auto *CE = dyn_cast<CastExpr>(E);
3374 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3377 // If this is a decay from variable width array, bail out.
3378 const Expr *SubExpr = CE->getSubExpr();
3379 if (SubExpr->getType()->isVariableArrayType())
3385 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
3387 ArrayRef<llvm::Value*> indices,
3391 const llvm::Twine &name = "arrayidx") {
3393 return CGF.EmitCheckedInBoundsGEP(ptr, indices, signedIndices,
3394 CodeGenFunction::NotSubtraction, loc,
3397 return CGF.Builder.CreateGEP(ptr, indices, name);
3401 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
3403 CharUnits eltSize) {
3404 // If we have a constant index, we can use the exact offset of the
3405 // element we're accessing.
3406 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3407 CharUnits offset = constantIdx->getZExtValue() * eltSize;
3408 return arrayAlign.alignmentAtOffset(offset);
3410 // Otherwise, use the worst-case alignment for any element.
3412 return arrayAlign.alignmentOfArrayElement(eltSize);
3416 static QualType getFixedSizeElementType(const ASTContext &ctx,
3417 const VariableArrayType *vla) {
3420 eltType = vla->getElementType();
3421 } while ((vla = ctx.getAsVariableArrayType(eltType)));
3425 /// Given an array base, check whether its member access belongs to a record
3426 /// with preserve_access_index attribute or not.
3427 static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) {
3428 if (!ArrayBase || !CGF.getDebugInfo())
3431 // Only support base as either a MemberExpr or DeclRefExpr.
3432 // DeclRefExpr to cover cases like:
3433 // struct s { int a; int b[10]; };
3436 // p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr.
3437 // p->b[5] is a MemberExpr example.
3438 const Expr *E = ArrayBase->IgnoreImpCasts();
3439 if (const auto *ME = dyn_cast<MemberExpr>(E))
3440 return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
3442 if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
3443 const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl());
3447 const auto *PtrT = VarDef->getType()->getAs<PointerType>();
3451 const auto *PointeeT = PtrT->getPointeeType()
3452 ->getUnqualifiedDesugaredType();
3453 if (const auto *RecT = dyn_cast<RecordType>(PointeeT))
3454 return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
3461 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
3462 ArrayRef<llvm::Value *> indices,
3463 QualType eltType, bool inbounds,
3464 bool signedIndices, SourceLocation loc,
3465 QualType *arrayType = nullptr,
3466 const Expr *Base = nullptr,
3467 const llvm::Twine &name = "arrayidx") {
3468 // All the indices except that last must be zero.
3470 for (auto idx : indices.drop_back())
3471 assert(isa<llvm::ConstantInt>(idx) &&
3472 cast<llvm::ConstantInt>(idx)->isZero());
3475 // Determine the element size of the statically-sized base. This is
3476 // the thing that the indices are expressed in terms of.
3477 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3478 eltType = getFixedSizeElementType(CGF.getContext(), vla);
3481 // We can use that to compute the best alignment of the element.
3482 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3483 CharUnits eltAlign =
3484 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3486 llvm::Value *eltPtr;
3487 auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
3489 (!CGF.IsInPreservedAIRegion && !IsPreserveAIArrayBase(CGF, Base))) {
3490 eltPtr = emitArraySubscriptGEP(
3491 CGF, addr.getPointer(), indices, inbounds, signedIndices,
3494 // Remember the original array subscript for bpf target
3495 unsigned idx = LastIndex->getZExtValue();
3496 llvm::DIType *DbgInfo = nullptr;
3498 DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc);
3499 eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getElementType(),
3505 return Address(eltPtr, eltAlign);
3508 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
3510 // The index must always be an integer, which is not an aggregate. Emit it
3511 // in lexical order (this complexity is, sadly, required by C++17).
3512 llvm::Value *IdxPre =
3513 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3514 bool SignedIndices = false;
3515 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3517 if (E->getLHS() != E->getIdx()) {
3518 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3519 Idx = EmitScalarExpr(E->getIdx());
3522 QualType IdxTy = E->getIdx()->getType();
3523 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3524 SignedIndices |= IdxSigned;
3526 if (SanOpts.has(SanitizerKind::ArrayBounds))
3527 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3529 // Extend or truncate the index type to 32 or 64-bits.
3530 if (Promote && Idx->getType() != IntPtrTy)
3531 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3537 // If the base is a vector type, then we are forming a vector element lvalue
3538 // with this subscript.
3539 if (E->getBase()->getType()->isVectorType() &&
3540 !isa<ExtVectorElementExpr>(E->getBase())) {
3541 // Emit the vector as an lvalue to get its address.
3542 LValue LHS = EmitLValue(E->getBase());
3543 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3544 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3545 return LValue::MakeVectorElt(LHS.getAddress(*this), Idx,
3546 E->getBase()->getType(), LHS.getBaseInfo(),
3550 // All the other cases basically behave like simple offsetting.
3552 // Handle the extvector case we ignored above.
3553 if (isa<ExtVectorElementExpr>(E->getBase())) {
3554 LValue LV = EmitLValue(E->getBase());
3555 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3556 Address Addr = EmitExtVectorElementLValue(LV);
3558 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3559 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3560 SignedIndices, E->getExprLoc());
3561 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3562 CGM.getTBAAInfoForSubobject(LV, EltType));
3565 LValueBaseInfo EltBaseInfo;
3566 TBAAAccessInfo EltTBAAInfo;
3567 Address Addr = Address::invalid();
3568 if (const VariableArrayType *vla =
3569 getContext().getAsVariableArrayType(E->getType())) {
3570 // The base must be a pointer, which is not an aggregate. Emit
3571 // it. It needs to be emitted first in case it's what captures
3573 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3574 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3576 // The element count here is the total number of non-VLA elements.
3577 llvm::Value *numElements = getVLASize(vla).NumElts;
3579 // Effectively, the multiply by the VLA size is part of the GEP.
3580 // GEP indexes are signed, and scaling an index isn't permitted to
3581 // signed-overflow, so we use the same semantics for our explicit
3582 // multiply. We suppress this if overflow is not undefined behavior.
3583 if (getLangOpts().isSignedOverflowDefined()) {
3584 Idx = Builder.CreateMul(Idx, numElements);
3586 Idx = Builder.CreateNSWMul(Idx, numElements);
3589 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3590 !getLangOpts().isSignedOverflowDefined(),
3591 SignedIndices, E->getExprLoc());
3593 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3594 // Indexing over an interface, as in "NSString *P; P[4];"
3596 // Emit the base pointer.
3597 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3598 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3600 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3601 llvm::Value *InterfaceSizeVal =
3602 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3604 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3606 // We don't necessarily build correct LLVM struct types for ObjC
3607 // interfaces, so we can't rely on GEP to do this scaling
3608 // correctly, so we need to cast to i8*. FIXME: is this actually
3609 // true? A lot of other things in the fragile ABI would break...
3610 llvm::Type *OrigBaseTy = Addr.getType();
3611 Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3614 CharUnits EltAlign =
3615 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3616 llvm::Value *EltPtr =
3617 emitArraySubscriptGEP(*this, Addr.getPointer(), ScaledIdx, false,
3618 SignedIndices, E->getExprLoc());
3619 Addr = Address(EltPtr, EltAlign);
3622 Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3623 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3624 // If this is A[i] where A is an array, the frontend will have decayed the
3625 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3626 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3627 // "gep x, i" here. Emit one "gep A, 0, i".
3628 assert(Array->getType()->isArrayType() &&
3629 "Array to pointer decay must have array source type!");
3631 // For simple multidimensional array indexing, set the 'accessed' flag for
3632 // better bounds-checking of the base expression.
3633 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3634 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3636 ArrayLV = EmitLValue(Array);
3637 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3639 // Propagate the alignment from the array itself to the result.
3640 QualType arrayType = Array->getType();
3641 Addr = emitArraySubscriptGEP(
3642 *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx},
3643 E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3644 E->getExprLoc(), &arrayType, E->getBase());
3645 EltBaseInfo = ArrayLV.getBaseInfo();
3646 EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3648 // The base must be a pointer; emit it with an estimate of its alignment.
3649 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3650 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3651 QualType ptrType = E->getBase()->getType();
3652 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3653 !getLangOpts().isSignedOverflowDefined(),
3654 SignedIndices, E->getExprLoc(), &ptrType,
3658 LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3660 if (getLangOpts().ObjC &&
3661 getLangOpts().getGC() != LangOptions::NonGC) {
3662 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3663 setObjCGCLValueClass(getContext(), E, LV);
3668 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
3669 LValueBaseInfo &BaseInfo,
3670 TBAAAccessInfo &TBAAInfo,
3671 QualType BaseTy, QualType ElTy,
3672 bool IsLowerBound) {
3674 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3675 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3676 if (BaseTy->isArrayType()) {
3677 Address Addr = BaseLVal.getAddress(CGF);
3678 BaseInfo = BaseLVal.getBaseInfo();
3680 // If the array type was an incomplete type, we need to make sure
3681 // the decay ends up being the right type.
3682 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3683 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3685 // Note that VLA pointers are always decayed, so we don't need to do
3687 if (!BaseTy->isVariableArrayType()) {
3688 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3689 "Expected pointer to array");
3690 Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3693 return CGF.Builder.CreateElementBitCast(Addr,
3694 CGF.ConvertTypeForMem(ElTy));
3696 LValueBaseInfo TypeBaseInfo;
3697 TBAAAccessInfo TypeTBAAInfo;
3698 CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &TypeBaseInfo,
3700 BaseInfo.mergeForCast(TypeBaseInfo);
3701 TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3702 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress(CGF)), Align);
3704 return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3707 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
3708 bool IsLowerBound) {
3709 QualType BaseTy = OMPArraySectionExpr::getBaseOriginalType(E->getBase());
3710 QualType ResultExprTy;
3711 if (auto *AT = getContext().getAsArrayType(BaseTy))
3712 ResultExprTy = AT->getElementType();
3714 ResultExprTy = BaseTy->getPointeeType();
3715 llvm::Value *Idx = nullptr;
3716 if (IsLowerBound || E->getColonLoc().isInvalid()) {
3717 // Requesting lower bound or upper bound, but without provided length and
3718 // without ':' symbol for the default length -> length = 1.
3719 // Idx = LowerBound ?: 0;
3720 if (auto *LowerBound = E->getLowerBound()) {
3721 Idx = Builder.CreateIntCast(
3722 EmitScalarExpr(LowerBound), IntPtrTy,
3723 LowerBound->getType()->hasSignedIntegerRepresentation());
3725 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3727 // Try to emit length or lower bound as constant. If this is possible, 1
3728 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3729 // IR (LB + Len) - 1.
3730 auto &C = CGM.getContext();
3731 auto *Length = E->getLength();
3732 llvm::APSInt ConstLength;
3734 // Idx = LowerBound + Length - 1;
3735 if (Length->isIntegerConstantExpr(ConstLength, C)) {
3736 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3739 auto *LowerBound = E->getLowerBound();
3740 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3741 if (LowerBound && LowerBound->isIntegerConstantExpr(ConstLowerBound, C)) {
3742 ConstLowerBound = ConstLowerBound.zextOrTrunc(PointerWidthInBits);
3743 LowerBound = nullptr;
3747 else if (!LowerBound)
3750 if (Length || LowerBound) {
3751 auto *LowerBoundVal =
3753 ? Builder.CreateIntCast(
3754 EmitScalarExpr(LowerBound), IntPtrTy,
3755 LowerBound->getType()->hasSignedIntegerRepresentation())
3756 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3759 ? Builder.CreateIntCast(
3760 EmitScalarExpr(Length), IntPtrTy,
3761 Length->getType()->hasSignedIntegerRepresentation())
3762 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3763 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3765 !getLangOpts().isSignedOverflowDefined());
3766 if (Length && LowerBound) {
3767 Idx = Builder.CreateSub(
3768 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3769 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3772 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3774 // Idx = ArraySize - 1;
3775 QualType ArrayTy = BaseTy->isPointerType()
3776 ? E->getBase()->IgnoreParenImpCasts()->getType()
3778 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3779 Length = VAT->getSizeExpr();
3780 if (Length->isIntegerConstantExpr(ConstLength, C))
3783 auto *CAT = C.getAsConstantArrayType(ArrayTy);
3784 ConstLength = CAT->getSize();
3787 auto *LengthVal = Builder.CreateIntCast(
3788 EmitScalarExpr(Length), IntPtrTy,
3789 Length->getType()->hasSignedIntegerRepresentation());
3790 Idx = Builder.CreateSub(
3791 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
3792 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3794 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
3796 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
3802 Address EltPtr = Address::invalid();
3803 LValueBaseInfo BaseInfo;
3804 TBAAAccessInfo TBAAInfo;
3805 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
3806 // The base must be a pointer, which is not an aggregate. Emit
3807 // it. It needs to be emitted first in case it's what captures
3810 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
3811 BaseTy, VLA->getElementType(), IsLowerBound);
3812 // The element count here is the total number of non-VLA elements.
3813 llvm::Value *NumElements = getVLASize(VLA).NumElts;
3815 // Effectively, the multiply by the VLA size is part of the GEP.
3816 // GEP indexes are signed, and scaling an index isn't permitted to
3817 // signed-overflow, so we use the same semantics for our explicit
3818 // multiply. We suppress this if overflow is not undefined behavior.
3819 if (getLangOpts().isSignedOverflowDefined())
3820 Idx = Builder.CreateMul(Idx, NumElements);
3822 Idx = Builder.CreateNSWMul(Idx, NumElements);
3823 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
3824 !getLangOpts().isSignedOverflowDefined(),
3825 /*signedIndices=*/false, E->getExprLoc());
3826 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3827 // If this is A[i] where A is an array, the frontend will have decayed the
3828 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3829 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3830 // "gep x, i" here. Emit one "gep A, 0, i".
3831 assert(Array->getType()->isArrayType() &&
3832 "Array to pointer decay must have array source type!");
3834 // For simple multidimensional array indexing, set the 'accessed' flag for
3835 // better bounds-checking of the base expression.
3836 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3837 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3839 ArrayLV = EmitLValue(Array);
3841 // Propagate the alignment from the array itself to the result.
3842 EltPtr = emitArraySubscriptGEP(
3843 *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx},
3844 ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
3845 /*signedIndices=*/false, E->getExprLoc());
3846 BaseInfo = ArrayLV.getBaseInfo();
3847 TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
3849 Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
3850 TBAAInfo, BaseTy, ResultExprTy,
3852 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
3853 !getLangOpts().isSignedOverflowDefined(),
3854 /*signedIndices=*/false, E->getExprLoc());
3857 return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
3860 LValue CodeGenFunction::
3861 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
3862 // Emit the base vector as an l-value.
3865 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
3867 // If it is a pointer to a vector, emit the address and form an lvalue with
3869 LValueBaseInfo BaseInfo;
3870 TBAAAccessInfo TBAAInfo;
3871 Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
3872 const auto *PT = E->getBase()->getType()->castAs<PointerType>();
3873 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
3874 Base.getQuals().removeObjCGCAttr();
3875 } else if (E->getBase()->isGLValue()) {
3876 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
3877 // emit the base as an lvalue.
3878 assert(E->getBase()->getType()->isVectorType());
3879 Base = EmitLValue(E->getBase());
3881 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
3882 assert(E->getBase()->getType()->isVectorType() &&
3883 "Result must be a vector");
3884 llvm::Value *Vec = EmitScalarExpr(E->getBase());
3886 // Store the vector to memory (because LValue wants an address).
3887 Address VecMem = CreateMemTemp(E->getBase()->getType());
3888 Builder.CreateStore(Vec, VecMem);
3889 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
3890 AlignmentSource::Decl);
3894 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
3896 // Encode the element access list into a vector of unsigned indices.
3897 SmallVector<uint32_t, 4> Indices;
3898 E->getEncodedElementAccess(Indices);
3900 if (Base.isSimple()) {
3901 llvm::Constant *CV =
3902 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
3903 return LValue::MakeExtVectorElt(Base.getAddress(*this), CV, type,
3904 Base.getBaseInfo(), TBAAAccessInfo());
3906 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
3908 llvm::Constant *BaseElts = Base.getExtVectorElts();
3909 SmallVector<llvm::Constant *, 4> CElts;
3911 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
3912 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
3913 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
3914 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
3915 Base.getBaseInfo(), TBAAAccessInfo());
3918 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
3919 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
3920 EmitIgnoredExpr(E->getBase());
3921 return EmitDeclRefLValue(DRE);
3924 Expr *BaseExpr = E->getBase();
3925 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
3928 LValueBaseInfo BaseInfo;
3929 TBAAAccessInfo TBAAInfo;
3930 Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
3931 QualType PtrTy = BaseExpr->getType()->getPointeeType();
3932 SanitizerSet SkippedChecks;
3933 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
3935 SkippedChecks.set(SanitizerKind::Alignment, true);
3936 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
3937 SkippedChecks.set(SanitizerKind::Null, true);
3938 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
3939 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
3940 BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
3942 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
3944 NamedDecl *ND = E->getMemberDecl();
3945 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
3946 LValue LV = EmitLValueForField(BaseLV, Field);
3947 setObjCGCLValueClass(getContext(), E, LV);
3948 if (getLangOpts().OpenMP) {
3949 // If the member was explicitly marked as nontemporal, mark it as
3950 // nontemporal. If the base lvalue is marked as nontemporal, mark access
3951 // to children as nontemporal too.
3952 if ((IsWrappedCXXThis(BaseExpr) &&
3953 CGM.getOpenMPRuntime().isNontemporalDecl(Field)) ||
3954 BaseLV.isNontemporal())
3955 LV.setNontemporal(/*Value=*/true);
3960 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3961 return EmitFunctionDeclLValue(*this, E, FD);
3963 llvm_unreachable("Unhandled member declaration!");
3966 /// Given that we are currently emitting a lambda, emit an l-value for
3967 /// one of its members.
3968 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
3969 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
3970 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
3971 QualType LambdaTagType =
3972 getContext().getTagDeclType(Field->getParent());
3973 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
3974 return EmitLValueForField(LambdaLV, Field);
3977 /// Get the field index in the debug info. The debug info structure/union
3978 /// will ignore the unnamed bitfields.
3979 unsigned CodeGenFunction::getDebugInfoFIndex(const RecordDecl *Rec,
3980 unsigned FieldIndex) {
3981 unsigned I = 0, Skipped = 0;
3983 for (auto F : Rec->getDefinition()->fields()) {
3984 if (I == FieldIndex)
3986 if (F->isUnnamedBitfield())
3991 return FieldIndex - Skipped;
3994 /// Get the address of a zero-sized field within a record. The resulting
3995 /// address doesn't necessarily have the right type.
3996 static Address emitAddrOfZeroSizeField(CodeGenFunction &CGF, Address Base,
3997 const FieldDecl *Field) {
3998 CharUnits Offset = CGF.getContext().toCharUnitsFromBits(
3999 CGF.getContext().getFieldOffset(Field));
4000 if (Offset.isZero())
4002 Base = CGF.Builder.CreateElementBitCast(Base, CGF.Int8Ty);
4003 return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset);
4006 /// Drill down to the storage of a field without walking into
4007 /// reference types.
4009 /// The resulting address doesn't necessarily have the right type.
4010 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
4011 const FieldDecl *field) {
4012 if (field->isZeroSize(CGF.getContext()))
4013 return emitAddrOfZeroSizeField(CGF, base, field);
4015 const RecordDecl *rec = field->getParent();
4018 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
4020 return CGF.Builder.CreateStructGEP(base, idx, field->getName());
4023 static Address emitPreserveStructAccess(CodeGenFunction &CGF, Address base,
4024 const FieldDecl *field) {
4025 const RecordDecl *rec = field->getParent();
4026 llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateRecordType(
4027 CGF.getContext().getRecordType(rec), rec->getLocation());
4030 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
4032 return CGF.Builder.CreatePreserveStructAccessIndex(
4033 base, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
4036 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
4037 const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
4041 if (RD->isDynamicClass())
4044 for (const auto &Base : RD->bases())
4045 if (hasAnyVptr(Base.getType(), Context))
4048 for (const FieldDecl *Field : RD->fields())
4049 if (hasAnyVptr(Field->getType(), Context))
4055 LValue CodeGenFunction::EmitLValueForField(LValue base,
4056 const FieldDecl *field) {
4057 LValueBaseInfo BaseInfo = base.getBaseInfo();
4059 if (field->isBitField()) {
4060 const CGRecordLayout &RL =
4061 CGM.getTypes().getCGRecordLayout(field->getParent());
4062 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
4063 Address Addr = base.getAddress(*this);
4064 unsigned Idx = RL.getLLVMFieldNo(field);
4065 const RecordDecl *rec = field->getParent();
4066 if (!IsInPreservedAIRegion &&
4067 (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
4069 // For structs, we GEP to the field that the record layout suggests.
4070 Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
4072 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4073 getContext().getRecordType(rec), rec->getLocation());
4074 Addr = Builder.CreatePreserveStructAccessIndex(Addr, Idx,
4075 getDebugInfoFIndex(rec, field->getFieldIndex()),
4079 // Get the access type.
4080 llvm::Type *FieldIntTy =
4081 llvm::Type::getIntNTy(getLLVMContext(), Info.StorageSize);
4082 if (Addr.getElementType() != FieldIntTy)
4083 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
4085 QualType fieldType =
4086 field->getType().withCVRQualifiers(base.getVRQualifiers());
4087 // TODO: Support TBAA for bit fields.
4088 LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
4089 return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
4093 // Fields of may-alias structures are may-alias themselves.
4094 // FIXME: this should get propagated down through anonymous structs
4096 QualType FieldType = field->getType();
4097 const RecordDecl *rec = field->getParent();
4098 AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
4099 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
4100 TBAAAccessInfo FieldTBAAInfo;
4101 if (base.getTBAAInfo().isMayAlias() ||
4102 rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
4103 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4104 } else if (rec->isUnion()) {
4105 // TODO: Support TBAA for unions.
4106 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4108 // If no base type been assigned for the base access, then try to generate
4109 // one for this base lvalue.
4110 FieldTBAAInfo = base.getTBAAInfo();
4111 if (!FieldTBAAInfo.BaseType) {
4112 FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
4113 assert(!FieldTBAAInfo.Offset &&
4114 "Nonzero offset for an access with no base type!");
4117 // Adjust offset to be relative to the base type.
4118 const ASTRecordLayout &Layout =
4119 getContext().getASTRecordLayout(field->getParent());
4120 unsigned CharWidth = getContext().getCharWidth();
4121 if (FieldTBAAInfo.BaseType)
4122 FieldTBAAInfo.Offset +=
4123 Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
4125 // Update the final access type and size.
4126 FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
4127 FieldTBAAInfo.Size =
4128 getContext().getTypeSizeInChars(FieldType).getQuantity();
4131 Address addr = base.getAddress(*this);
4132 if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
4133 if (CGM.getCodeGenOpts().StrictVTablePointers &&
4134 ClassDef->isDynamicClass()) {
4135 // Getting to any field of dynamic object requires stripping dynamic
4136 // information provided by invariant.group. This is because accessing
4137 // fields may leak the real address of dynamic object, which could result
4138 // in miscompilation when leaked pointer would be compared.
4139 auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
4140 addr = Address(stripped, addr.getAlignment());
4144 unsigned RecordCVR = base.getVRQualifiers();
4145 if (rec->isUnion()) {
4146 // For unions, there is no pointer adjustment.
4147 if (CGM.getCodeGenOpts().StrictVTablePointers &&
4148 hasAnyVptr(FieldType, getContext()))
4149 // Because unions can easily skip invariant.barriers, we need to add
4150 // a barrier every time CXXRecord field with vptr is referenced.
4151 addr = Address(Builder.CreateLaunderInvariantGroup(addr.getPointer()),
4152 addr.getAlignment());
4154 if (IsInPreservedAIRegion ||
4155 (getDebugInfo() && rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
4156 // Remember the original union field index
4157 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4158 getContext().getRecordType(rec), rec->getLocation());
4160 Builder.CreatePreserveUnionAccessIndex(
4161 addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
4162 addr.getAlignment());
4165 if (FieldType->isReferenceType())
4166 addr = Builder.CreateElementBitCast(
4167 addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4169 if (!IsInPreservedAIRegion &&
4170 (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>()))
4171 // For structs, we GEP to the field that the record layout suggests.
4172 addr = emitAddrOfFieldStorage(*this, addr, field);
4174 // Remember the original struct field index
4175 addr = emitPreserveStructAccess(*this, addr, field);
4178 // If this is a reference field, load the reference right now.
4179 if (FieldType->isReferenceType()) {
4181 MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4182 if (RecordCVR & Qualifiers::Volatile)
4183 RefLVal.getQuals().addVolatile();
4184 addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
4186 // Qualifiers on the struct don't apply to the referencee.
4188 FieldType = FieldType->getPointeeType();
4191 // Make sure that the address is pointing to the right type. This is critical
4192 // for both unions and structs. A union needs a bitcast, a struct element
4193 // will need a bitcast if the LLVM type laid out doesn't match the desired
4195 addr = Builder.CreateElementBitCast(
4196 addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4198 if (field->hasAttr<AnnotateAttr>())
4199 addr = EmitFieldAnnotations(field, addr);
4201 LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4202 LV.getQuals().addCVRQualifiers(RecordCVR);
4204 // __weak attribute on a field is ignored.
4205 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
4206 LV.getQuals().removeObjCGCAttr();
4212 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
4213 const FieldDecl *Field) {
4214 QualType FieldType = Field->getType();
4216 if (!FieldType->isReferenceType())
4217 return EmitLValueForField(Base, Field);
4219 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(*this), Field);
4221 // Make sure that the address is pointing to the right type.
4222 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
4223 V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
4225 // TODO: Generate TBAA information that describes this access as a structure
4226 // member access and not just an access to an object of the field's type. This
4227 // should be similar to what we do in EmitLValueForField().
4228 LValueBaseInfo BaseInfo = Base.getBaseInfo();
4229 AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
4230 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
4231 return MakeAddrLValue(V, FieldType, FieldBaseInfo,
4232 CGM.getTBAAInfoForSubobject(Base, FieldType));
4235 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
4236 if (E->isFileScope()) {
4237 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
4238 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
4240 if (E->getType()->isVariablyModifiedType())
4241 // make sure to emit the VLA size.
4242 EmitVariablyModifiedType(E->getType());
4244 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4245 const Expr *InitExpr = E->getInitializer();
4246 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4248 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4254 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
4255 if (!E->isGLValue())
4256 // Initializing an aggregate temporary in C++11: T{...}.
4257 return EmitAggExprToLValue(E);
4259 // An lvalue initializer list must be initializing a reference.
4260 assert(E->isTransparent() && "non-transparent glvalue init list");
4261 return EmitLValue(E->getInit(0));
4264 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4265 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4266 /// LValue is returned and the current block has been terminated.
4267 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
4268 const Expr *Operand) {
4269 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4270 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4274 return CGF.EmitLValue(Operand);
4277 LValue CodeGenFunction::
4278 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) {
4279 if (!expr->isGLValue()) {
4280 // ?: here should be an aggregate.
4281 assert(hasAggregateEvaluationKind(expr->getType()) &&
4282 "Unexpected conditional operator!");
4283 return EmitAggExprToLValue(expr);
4286 OpaqueValueMapping binding(*this, expr);
4288 const Expr *condExpr = expr->getCond();
4290 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4291 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4292 if (!CondExprBool) std::swap(live, dead);
4294 if (!ContainsLabel(dead)) {
4295 // If the true case is live, we need to track its region.
4297 incrementProfileCounter(expr);
4298 return EmitLValue(live);
4302 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4303 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4304 llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4306 ConditionalEvaluation eval(*this);
4307 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4309 // Any temporaries created here are conditional.
4310 EmitBlock(lhsBlock);
4311 incrementProfileCounter(expr);
4313 Optional<LValue> lhs =
4314 EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4317 if (lhs && !lhs->isSimple())
4318 return EmitUnsupportedLValue(expr, "conditional operator");
4320 lhsBlock = Builder.GetInsertBlock();
4322 Builder.CreateBr(contBlock);
4324 // Any temporaries created here are conditional.
4325 EmitBlock(rhsBlock);
4327 Optional<LValue> rhs =
4328 EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4330 if (rhs && !rhs->isSimple())
4331 return EmitUnsupportedLValue(expr, "conditional operator");
4332 rhsBlock = Builder.GetInsertBlock();
4334 EmitBlock(contBlock);
4337 llvm::PHINode *phi =
4338 Builder.CreatePHI(lhs->getPointer(*this)->getType(), 2, "cond-lvalue");
4339 phi->addIncoming(lhs->getPointer(*this), lhsBlock);
4340 phi->addIncoming(rhs->getPointer(*this), rhsBlock);
4341 Address result(phi, std::min(lhs->getAlignment(), rhs->getAlignment()));
4342 AlignmentSource alignSource =
4343 std::max(lhs->getBaseInfo().getAlignmentSource(),
4344 rhs->getBaseInfo().getAlignmentSource());
4345 TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForConditionalOperator(
4346 lhs->getTBAAInfo(), rhs->getTBAAInfo());
4347 return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4350 assert((lhs || rhs) &&
4351 "both operands of glvalue conditional are throw-expressions?");
4352 return lhs ? *lhs : *rhs;
4356 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4357 /// type. If the cast is to a reference, we can have the usual lvalue result,
4358 /// otherwise if a cast is needed by the code generator in an lvalue context,
4359 /// then it must mean that we need the address of an aggregate in order to
4360 /// access one of its members. This can happen for all the reasons that casts
4361 /// are permitted with aggregate result, including noop aggregate casts, and
4362 /// cast from scalar to union.
4363 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
4364 switch (E->getCastKind()) {
4367 case CK_LValueToRValueBitCast:
4368 case CK_ArrayToPointerDecay:
4369 case CK_FunctionToPointerDecay:
4370 case CK_NullToMemberPointer:
4371 case CK_NullToPointer:
4372 case CK_IntegralToPointer:
4373 case CK_PointerToIntegral:
4374 case CK_PointerToBoolean:
4375 case CK_VectorSplat:
4376 case CK_IntegralCast:
4377 case CK_BooleanToSignedIntegral:
4378 case CK_IntegralToBoolean:
4379 case CK_IntegralToFloating:
4380 case CK_FloatingToIntegral:
4381 case CK_FloatingToBoolean:
4382 case CK_FloatingCast:
4383 case CK_FloatingRealToComplex:
4384 case CK_FloatingComplexToReal:
4385 case CK_FloatingComplexToBoolean:
4386 case CK_FloatingComplexCast:
4387 case CK_FloatingComplexToIntegralComplex:
4388 case CK_IntegralRealToComplex:
4389 case CK_IntegralComplexToReal:
4390 case CK_IntegralComplexToBoolean:
4391 case CK_IntegralComplexCast:
4392 case CK_IntegralComplexToFloatingComplex:
4393 case CK_DerivedToBaseMemberPointer:
4394 case CK_BaseToDerivedMemberPointer:
4395 case CK_MemberPointerToBoolean:
4396 case CK_ReinterpretMemberPointer:
4397 case CK_AnyPointerToBlockPointerCast:
4398 case CK_ARCProduceObject:
4399 case CK_ARCConsumeObject:
4400 case CK_ARCReclaimReturnedObject:
4401 case CK_ARCExtendBlockObject:
4402 case CK_CopyAndAutoreleaseBlockObject:
4403 case CK_IntToOCLSampler:
4404 case CK_FixedPointCast:
4405 case CK_FixedPointToBoolean:
4406 case CK_FixedPointToIntegral:
4407 case CK_IntegralToFixedPoint:
4408 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4411 llvm_unreachable("dependent cast kind in IR gen!");
4413 case CK_BuiltinFnToFnPtr:
4414 llvm_unreachable("builtin functions are handled elsewhere");
4416 // These are never l-values; just use the aggregate emission code.
4417 case CK_NonAtomicToAtomic:
4418 case CK_AtomicToNonAtomic:
4419 return EmitAggExprToLValue(E);
4422 LValue LV = EmitLValue(E->getSubExpr());
4423 Address V = LV.getAddress(*this);
4424 const auto *DCE = cast<CXXDynamicCastExpr>(E);
4425 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
4428 case CK_ConstructorConversion:
4429 case CK_UserDefinedConversion:
4430 case CK_CPointerToObjCPointerCast:
4431 case CK_BlockPointerToObjCPointerCast:
4433 case CK_LValueToRValue:
4434 return EmitLValue(E->getSubExpr());
4436 case CK_UncheckedDerivedToBase:
4437 case CK_DerivedToBase: {
4438 const auto *DerivedClassTy =
4439 E->getSubExpr()->getType()->castAs<RecordType>();
4440 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4442 LValue LV = EmitLValue(E->getSubExpr());
4443 Address This = LV.getAddress(*this);
4445 // Perform the derived-to-base conversion
4446 Address Base = GetAddressOfBaseClass(
4447 This, DerivedClassDecl, E->path_begin(), E->path_end(),
4448 /*NullCheckValue=*/false, E->getExprLoc());
4450 // TODO: Support accesses to members of base classes in TBAA. For now, we
4451 // conservatively pretend that the complete object is of the base class
4453 return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4454 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4457 return EmitAggExprToLValue(E);
4458 case CK_BaseToDerived: {
4459 const auto *DerivedClassTy = E->getType()->castAs<RecordType>();
4460 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4462 LValue LV = EmitLValue(E->getSubExpr());
4464 // Perform the base-to-derived conversion
4465 Address Derived = GetAddressOfDerivedClass(
4466 LV.getAddress(*this), DerivedClassDecl, E->path_begin(), E->path_end(),
4467 /*NullCheckValue=*/false);
4469 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
4470 // performed and the object is not of the derived type.
4471 if (sanitizePerformTypeCheck())
4472 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
4473 Derived.getPointer(), E->getType());
4475 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
4476 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(),
4477 /*MayBeNull=*/false, CFITCK_DerivedCast,
4480 return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
4481 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4483 case CK_LValueBitCast: {
4484 // This must be a reinterpret_cast (or c-style equivalent).
4485 const auto *CE = cast<ExplicitCastExpr>(E);
4487 CGM.EmitExplicitCastExprType(CE, this);
4488 LValue LV = EmitLValue(E->getSubExpr());
4489 Address V = Builder.CreateBitCast(LV.getAddress(*this),
4490 ConvertType(CE->getTypeAsWritten()));
4492 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
4493 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(),
4494 /*MayBeNull=*/false, CFITCK_UnrelatedCast,
4497 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4498 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4500 case CK_AddressSpaceConversion: {
4501 LValue LV = EmitLValue(E->getSubExpr());
4502 QualType DestTy = getContext().getPointerType(E->getType());
4503 llvm::Value *V = getTargetHooks().performAddrSpaceCast(
4504 *this, LV.getPointer(*this),
4505 E->getSubExpr()->getType().getAddressSpace(),
4506 E->getType().getAddressSpace(), ConvertType(DestTy));
4507 return MakeAddrLValue(Address(V, LV.getAddress(*this).getAlignment()),
4508 E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
4510 case CK_ObjCObjectLValueCast: {
4511 LValue LV = EmitLValue(E->getSubExpr());
4512 Address V = Builder.CreateElementBitCast(LV.getAddress(*this),
4513 ConvertType(E->getType()));
4514 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
4515 CGM.getTBAAInfoForSubobject(LV, E->getType()));
4517 case CK_ZeroToOCLOpaqueType:
4518 llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
4521 llvm_unreachable("Unhandled lvalue cast kind?");
4524 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
4525 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
4526 return getOrCreateOpaqueLValueMapping(e);
4530 CodeGenFunction::getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e) {
4531 assert(OpaqueValueMapping::shouldBindAsLValue(e));
4533 llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
4534 it = OpaqueLValues.find(e);
4536 if (it != OpaqueLValues.end())
4539 assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
4540 return EmitLValue(e->getSourceExpr());
4544 CodeGenFunction::getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e) {
4545 assert(!OpaqueValueMapping::shouldBindAsLValue(e));
4547 llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
4548 it = OpaqueRValues.find(e);
4550 if (it != OpaqueRValues.end())
4553 assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
4554 return EmitAnyExpr(e->getSourceExpr());
4557 RValue CodeGenFunction::EmitRValueForField(LValue LV,
4558 const FieldDecl *FD,
4559 SourceLocation Loc) {
4560 QualType FT = FD->getType();
4561 LValue FieldLV = EmitLValueForField(LV, FD);
4562 switch (getEvaluationKind(FT)) {
4564 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
4566 return FieldLV.asAggregateRValue(*this);
4568 // This routine is used to load fields one-by-one to perform a copy, so
4569 // don't load reference fields.
4570 if (FD->getType()->isReferenceType())
4571 return RValue::get(FieldLV.getPointer(*this));
4572 // Call EmitLoadOfScalar except when the lvalue is a bitfield to emit a
4574 if (FieldLV.isBitField())
4575 return EmitLoadOfLValue(FieldLV, Loc);
4576 return RValue::get(EmitLoadOfScalar(FieldLV, Loc));
4578 llvm_unreachable("bad evaluation kind");
4581 //===--------------------------------------------------------------------===//
4582 // Expression Emission
4583 //===--------------------------------------------------------------------===//
4585 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
4586 ReturnValueSlot ReturnValue) {
4587 // Builtins never have block type.
4588 if (E->getCallee()->getType()->isBlockPointerType())
4589 return EmitBlockCallExpr(E, ReturnValue);
4591 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
4592 return EmitCXXMemberCallExpr(CE, ReturnValue);
4594 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
4595 return EmitCUDAKernelCallExpr(CE, ReturnValue);
4597 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
4598 if (const CXXMethodDecl *MD =
4599 dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl()))
4600 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
4602 CGCallee callee = EmitCallee(E->getCallee());
4604 if (callee.isBuiltin()) {
4605 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
4609 if (callee.isPseudoDestructor()) {
4610 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
4613 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
4616 /// Emit a CallExpr without considering whether it might be a subclass.
4617 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
4618 ReturnValueSlot ReturnValue) {
4619 CGCallee Callee = EmitCallee(E->getCallee());
4620 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
4623 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
4625 if (auto builtinID = FD->getBuiltinID()) {
4626 // Replaceable builtin provide their own implementation of a builtin. Unless
4627 // we are in the builtin implementation itself, don't call the actual
4628 // builtin. If we are in the builtin implementation, avoid trivial infinite
4630 if (!FD->isInlineBuiltinDeclaration() ||
4631 CGF.CurFn->getName() == FD->getName())
4632 return CGCallee::forBuiltin(builtinID, FD);
4635 llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
4636 return CGCallee::forDirect(calleePtr, GlobalDecl(FD));
4639 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
4640 E = E->IgnoreParens();
4642 // Look through function-to-pointer decay.
4643 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
4644 if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
4645 ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
4646 return EmitCallee(ICE->getSubExpr());
4649 // Resolve direct calls.
4650 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
4651 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
4652 return EmitDirectCallee(*this, FD);
4654 } else if (auto ME = dyn_cast<MemberExpr>(E)) {
4655 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
4656 EmitIgnoredExpr(ME->getBase());
4657 return EmitDirectCallee(*this, FD);
4660 // Look through template substitutions.
4661 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
4662 return EmitCallee(NTTP->getReplacement());
4664 // Treat pseudo-destructor calls differently.
4665 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
4666 return CGCallee::forPseudoDestructor(PDE);
4669 // Otherwise, we have an indirect reference.
4670 llvm::Value *calleePtr;
4671 QualType functionType;
4672 if (auto ptrType = E->getType()->getAs<PointerType>()) {
4673 calleePtr = EmitScalarExpr(E);
4674 functionType = ptrType->getPointeeType();
4676 functionType = E->getType();
4677 calleePtr = EmitLValue(E).getPointer(*this);
4679 assert(functionType->isFunctionType());
4682 if (const auto *VD =
4683 dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
4684 GD = GlobalDecl(VD);
4686 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
4687 CGCallee callee(calleeInfo, calleePtr);
4691 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
4692 // Comma expressions just emit their LHS then their RHS as an l-value.
4693 if (E->getOpcode() == BO_Comma) {
4694 EmitIgnoredExpr(E->getLHS());
4695 EnsureInsertPoint();
4696 return EmitLValue(E->getRHS());
4699 if (E->getOpcode() == BO_PtrMemD ||
4700 E->getOpcode() == BO_PtrMemI)
4701 return EmitPointerToDataMemberBinaryExpr(E);
4703 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
4705 // Note that in all of these cases, __block variables need the RHS
4706 // evaluated first just in case the variable gets moved by the RHS.
4708 switch (getEvaluationKind(E->getType())) {
4710 switch (E->getLHS()->getType().getObjCLifetime()) {
4711 case Qualifiers::OCL_Strong:
4712 return EmitARCStoreStrong(E, /*ignored*/ false).first;
4714 case Qualifiers::OCL_Autoreleasing:
4715 return EmitARCStoreAutoreleasing(E).first;
4717 // No reason to do any of these differently.
4718 case Qualifiers::OCL_None:
4719 case Qualifiers::OCL_ExplicitNone:
4720 case Qualifiers::OCL_Weak:
4724 RValue RV = EmitAnyExpr(E->getRHS());
4725 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
4727 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
4728 EmitStoreThroughLValue(RV, LV);
4729 if (getLangOpts().OpenMP)
4730 CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this,
4736 return EmitComplexAssignmentLValue(E);
4739 return EmitAggExprToLValue(E);
4741 llvm_unreachable("bad evaluation kind");
4744 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
4745 RValue RV = EmitCallExpr(E);
4748 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4749 AlignmentSource::Decl);
4751 assert(E->getCallReturnType(getContext())->isReferenceType() &&
4752 "Can't have a scalar return unless the return type is a "
4755 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4758 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
4759 // FIXME: This shouldn't require another copy.
4760 return EmitAggExprToLValue(E);
4763 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
4764 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
4765 && "binding l-value to type which needs a temporary");
4766 AggValueSlot Slot = CreateAggTemp(E->getType());
4767 EmitCXXConstructExpr(E, Slot);
4768 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4772 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
4773 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
4776 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
4777 return Builder.CreateElementBitCast(CGM.GetAddrOfUuidDescriptor(E),
4778 ConvertType(E->getType()));
4781 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
4782 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
4783 AlignmentSource::Decl);
4787 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
4788 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
4789 Slot.setExternallyDestructed();
4790 EmitAggExpr(E->getSubExpr(), Slot);
4791 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
4792 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
4795 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
4796 RValue RV = EmitObjCMessageExpr(E);
4799 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4800 AlignmentSource::Decl);
4802 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
4803 "Can't have a scalar return unless the return type is a "
4806 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
4809 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
4811 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
4812 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
4815 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
4816 const ObjCIvarDecl *Ivar) {
4817 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
4820 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
4821 llvm::Value *BaseValue,
4822 const ObjCIvarDecl *Ivar,
4823 unsigned CVRQualifiers) {
4824 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
4825 Ivar, CVRQualifiers);
4828 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
4829 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
4830 llvm::Value *BaseValue = nullptr;
4831 const Expr *BaseExpr = E->getBase();
4832 Qualifiers BaseQuals;
4835 BaseValue = EmitScalarExpr(BaseExpr);
4836 ObjectTy = BaseExpr->getType()->getPointeeType();
4837 BaseQuals = ObjectTy.getQualifiers();
4839 LValue BaseLV = EmitLValue(BaseExpr);
4840 BaseValue = BaseLV.getPointer(*this);
4841 ObjectTy = BaseExpr->getType();
4842 BaseQuals = ObjectTy.getQualifiers();
4846 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
4847 BaseQuals.getCVRQualifiers());
4848 setObjCGCLValueClass(getContext(), E, LV);
4852 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
4853 // Can only get l-value for message expression returning aggregate type
4854 RValue RV = EmitAnyExprToTemp(E);
4855 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
4856 AlignmentSource::Decl);
4859 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
4860 const CallExpr *E, ReturnValueSlot ReturnValue,
4861 llvm::Value *Chain) {
4862 // Get the actual function type. The callee type will always be a pointer to
4863 // function type or a block pointer type.
4864 assert(CalleeType->isFunctionPointerType() &&
4865 "Call must have function pointer type!");
4867 const Decl *TargetDecl =
4868 OrigCallee.getAbstractInfo().getCalleeDecl().getDecl();
4870 CalleeType = getContext().getCanonicalType(CalleeType);
4872 auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
4874 CGCallee Callee = OrigCallee;
4876 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) &&
4877 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4878 if (llvm::Constant *PrefixSig =
4879 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
4880 SanitizerScope SanScope(this);
4881 // Remove any (C++17) exception specifications, to allow calling e.g. a
4882 // noexcept function through a non-noexcept pointer.
4884 getContext().getFunctionTypeWithExceptionSpec(PointeeType, EST_None);
4885 llvm::Constant *FTRTTIConst =
4886 CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true);
4887 llvm::Type *PrefixStructTyElems[] = {PrefixSig->getType(), Int32Ty};
4888 llvm::StructType *PrefixStructTy = llvm::StructType::get(
4889 CGM.getLLVMContext(), PrefixStructTyElems, /*isPacked=*/true);
4891 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4893 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast(
4894 CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy));
4895 llvm::Value *CalleeSigPtr =
4896 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0);
4897 llvm::Value *CalleeSig =
4898 Builder.CreateAlignedLoad(CalleeSigPtr, getIntAlign());
4899 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
4901 llvm::BasicBlock *Cont = createBasicBlock("cont");
4902 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
4903 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
4905 EmitBlock(TypeCheck);
4906 llvm::Value *CalleeRTTIPtr =
4907 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1);
4908 llvm::Value *CalleeRTTIEncoded =
4909 Builder.CreateAlignedLoad(CalleeRTTIPtr, getPointerAlign());
4910 llvm::Value *CalleeRTTI =
4911 DecodeAddrUsedInPrologue(CalleePtr, CalleeRTTIEncoded);
4912 llvm::Value *CalleeRTTIMatch =
4913 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst);
4914 llvm::Constant *StaticData[] = {EmitCheckSourceLocation(E->getBeginLoc()),
4915 EmitCheckTypeDescriptor(CalleeType)};
4916 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function),
4917 SanitizerHandler::FunctionTypeMismatch, StaticData,
4918 {CalleePtr, CalleeRTTI, FTRTTIConst});
4920 Builder.CreateBr(Cont);
4925 const auto *FnType = cast<FunctionType>(PointeeType);
4927 // If we are checking indirect calls and this call is indirect, check that the
4928 // function pointer is a member of the bit set for the function type.
4929 if (SanOpts.has(SanitizerKind::CFIICall) &&
4930 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
4931 SanitizerScope SanScope(this);
4932 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
4935 if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
4936 MD = CGM.CreateMetadataIdentifierGeneralized(QualType(FnType, 0));
4938 MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
4940 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
4942 llvm::Value *CalleePtr = Callee.getFunctionPointer();
4943 llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy);
4944 llvm::Value *TypeTest = Builder.CreateCall(
4945 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId});
4947 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
4948 llvm::Constant *StaticData[] = {
4949 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
4950 EmitCheckSourceLocation(E->getBeginLoc()),
4951 EmitCheckTypeDescriptor(QualType(FnType, 0)),
4953 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
4954 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
4955 CastedCallee, StaticData);
4957 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
4958 SanitizerHandler::CFICheckFail, StaticData,
4959 {CastedCallee, llvm::UndefValue::get(IntPtrTy)});
4965 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)),
4966 CGM.getContext().VoidPtrTy);
4968 // C++17 requires that we evaluate arguments to a call using assignment syntax
4969 // right-to-left, and that we evaluate arguments to certain other operators
4970 // left-to-right. Note that we allow this to override the order dictated by
4971 // the calling convention on the MS ABI, which means that parameter
4972 // destruction order is not necessarily reverse construction order.
4973 // FIXME: Revisit this based on C++ committee response to unimplementability.
4974 EvaluationOrder Order = EvaluationOrder::Default;
4975 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
4976 if (OCE->isAssignmentOp())
4977 Order = EvaluationOrder::ForceRightToLeft;
4979 switch (OCE->getOperator()) {
4981 case OO_GreaterGreater:
4986 Order = EvaluationOrder::ForceLeftToRight;
4994 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(),
4995 E->getDirectCallee(), /*ParamsToSkip*/ 0, Order);
4997 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
4998 Args, FnType, /*ChainCall=*/Chain);
5001 // If the expression that denotes the called function has a type
5002 // that does not include a prototype, [the default argument
5003 // promotions are performed]. If the number of arguments does not
5004 // equal the number of parameters, the behavior is undefined. If
5005 // the function is defined with a type that includes a prototype,
5006 // and either the prototype ends with an ellipsis (, ...) or the
5007 // types of the arguments after promotion are not compatible with
5008 // the types of the parameters, the behavior is undefined. If the
5009 // function is defined with a type that does not include a
5010 // prototype, and the types of the arguments after promotion are
5011 // not compatible with those of the parameters after promotion,
5012 // the behavior is undefined [except in some trivial cases].
5013 // That is, in the general case, we should assume that a call
5014 // through an unprototyped function type works like a *non-variadic*
5015 // call. The way we make this work is to cast to the exact type
5016 // of the promoted arguments.
5018 // Chain calls use this same code path to add the invisible chain parameter
5019 // to the function type.
5020 if (isa<FunctionNoProtoType>(FnType) || Chain) {
5021 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
5022 CalleeTy = CalleeTy->getPointerTo();
5024 llvm::Value *CalleePtr = Callee.getFunctionPointer();
5025 CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
5026 Callee.setFunctionPointer(CalleePtr);
5029 llvm::CallBase *CallOrInvoke = nullptr;
5030 RValue Call = EmitCall(FnInfo, Callee, ReturnValue, Args, &CallOrInvoke,
5033 // Generate function declaration DISuprogram in order to be used
5034 // in debug info about call sites.
5035 if (CGDebugInfo *DI = getDebugInfo()) {
5036 if (auto *CalleeDecl = dyn_cast_or_null<FunctionDecl>(TargetDecl))
5037 DI->EmitFuncDeclForCallSite(CallOrInvoke, QualType(FnType, 0),
5044 LValue CodeGenFunction::
5045 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
5046 Address BaseAddr = Address::invalid();
5047 if (E->getOpcode() == BO_PtrMemI) {
5048 BaseAddr = EmitPointerWithAlignment(E->getLHS());
5050 BaseAddr = EmitLValue(E->getLHS()).getAddress(*this);
5053 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
5054 const auto *MPT = E->getRHS()->getType()->castAs<MemberPointerType>();
5056 LValueBaseInfo BaseInfo;
5057 TBAAAccessInfo TBAAInfo;
5058 Address MemberAddr =
5059 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo,
5062 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo);
5065 /// Given the address of a temporary variable, produce an r-value of
5067 RValue CodeGenFunction::convertTempToRValue(Address addr,
5069 SourceLocation loc) {
5070 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
5071 switch (getEvaluationKind(type)) {
5073 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
5075 return lvalue.asAggregateRValue(*this);
5077 return RValue::get(EmitLoadOfScalar(lvalue, loc));
5079 llvm_unreachable("bad evaluation kind");
5082 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
5083 assert(Val->getType()->isFPOrFPVectorTy());
5084 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
5087 llvm::MDBuilder MDHelper(getLLVMContext());
5088 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
5090 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
5094 struct LValueOrRValue {
5100 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
5101 const PseudoObjectExpr *E,
5103 AggValueSlot slot) {
5104 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
5106 // Find the result expression, if any.
5107 const Expr *resultExpr = E->getResultExpr();
5108 LValueOrRValue result;
5110 for (PseudoObjectExpr::const_semantics_iterator
5111 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
5112 const Expr *semantic = *i;
5114 // If this semantic expression is an opaque value, bind it
5115 // to the result of its source expression.
5116 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
5117 // Skip unique OVEs.
5118 if (ov->isUnique()) {
5119 assert(ov != resultExpr &&
5120 "A unique OVE cannot be used as the result expression");
5124 // If this is the result expression, we may need to evaluate
5125 // directly into the slot.
5126 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
5128 if (ov == resultExpr && ov->isRValue() && !forLValue &&
5129 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
5130 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
5131 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
5132 AlignmentSource::Decl);
5133 opaqueData = OVMA::bind(CGF, ov, LV);
5134 result.RV = slot.asRValue();
5136 // Otherwise, emit as normal.
5138 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
5140 // If this is the result, also evaluate the result now.
5141 if (ov == resultExpr) {
5143 result.LV = CGF.EmitLValue(ov);
5145 result.RV = CGF.EmitAnyExpr(ov, slot);
5149 opaques.push_back(opaqueData);
5151 // Otherwise, if the expression is the result, evaluate it
5152 // and remember the result.
5153 } else if (semantic == resultExpr) {
5155 result.LV = CGF.EmitLValue(semantic);
5157 result.RV = CGF.EmitAnyExpr(semantic, slot);
5159 // Otherwise, evaluate the expression in an ignored context.
5161 CGF.EmitIgnoredExpr(semantic);
5165 // Unbind all the opaques now.
5166 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
5167 opaques[i].unbind(CGF);
5172 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
5173 AggValueSlot slot) {
5174 return emitPseudoObjectExpr(*this, E, false, slot).RV;
5177 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
5178 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;