clang 20.0.0git
CGExpr.cpp
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1//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
2//
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
6//
7//===----------------------------------------------------------------------===//
8//
9// This contains code to emit Expr nodes as LLVM code.
10//
11//===----------------------------------------------------------------------===//
12
13#include "ABIInfoImpl.h"
14#include "CGCUDARuntime.h"
15#include "CGCXXABI.h"
16#include "CGCall.h"
17#include "CGCleanup.h"
18#include "CGDebugInfo.h"
19#include "CGObjCRuntime.h"
20#include "CGOpenMPRuntime.h"
21#include "CGRecordLayout.h"
22#include "CodeGenFunction.h"
23#include "CodeGenModule.h"
24#include "ConstantEmitter.h"
25#include "TargetInfo.h"
27#include "clang/AST/Attr.h"
28#include "clang/AST/DeclObjC.h"
29#include "clang/AST/NSAPI.h"
34#include "llvm/ADT/STLExtras.h"
35#include "llvm/ADT/ScopeExit.h"
36#include "llvm/ADT/StringExtras.h"
37#include "llvm/IR/DataLayout.h"
38#include "llvm/IR/Intrinsics.h"
39#include "llvm/IR/LLVMContext.h"
40#include "llvm/IR/MDBuilder.h"
41#include "llvm/IR/MatrixBuilder.h"
42#include "llvm/Support/ConvertUTF.h"
43#include "llvm/Support/Endian.h"
44#include "llvm/Support/MathExtras.h"
45#include "llvm/Support/Path.h"
46#include "llvm/Support/xxhash.h"
47#include "llvm/Transforms/Utils/SanitizerStats.h"
48
49#include <optional>
50#include <string>
51
52using namespace clang;
53using namespace CodeGen;
54
55// TODO: Introduce frontend options to enabled per sanitizers, similar to
56// `fsanitize-trap`.
57static llvm::cl::opt<bool> ClSanitizeGuardChecks(
58 "ubsan-guard-checks", llvm::cl::Optional,
59 llvm::cl::desc("Guard UBSAN checks with `llvm.allow.ubsan.check()`."));
60
61//===--------------------------------------------------------------------===//
62// Defines for metadata
63//===--------------------------------------------------------------------===//
64
65// Those values are crucial to be the SAME as in ubsan runtime library.
67 /// An integer type.
68 TK_Integer = 0x0000,
69 /// A floating-point type.
70 TK_Float = 0x0001,
71 /// An _BitInt(N) type.
72 TK_BitInt = 0x0002,
73 /// Any other type. The value representation is unspecified.
74 TK_Unknown = 0xffff
75};
76
77//===--------------------------------------------------------------------===//
78// Miscellaneous Helper Methods
79//===--------------------------------------------------------------------===//
80
81/// CreateTempAlloca - This creates a alloca and inserts it into the entry
82/// block.
84CodeGenFunction::CreateTempAllocaWithoutCast(llvm::Type *Ty, CharUnits Align,
85 const Twine &Name,
86 llvm::Value *ArraySize) {
87 auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
88 Alloca->setAlignment(Align.getAsAlign());
89 return RawAddress(Alloca, Ty, Align, KnownNonNull);
90}
91
92/// CreateTempAlloca - This creates a alloca and inserts it into the entry
93/// block. The alloca is casted to default address space if necessary.
95 const Twine &Name,
96 llvm::Value *ArraySize,
97 RawAddress *AllocaAddr) {
98 auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
99 if (AllocaAddr)
100 *AllocaAddr = Alloca;
101 llvm::Value *V = Alloca.getPointer();
102 // Alloca always returns a pointer in alloca address space, which may
103 // be different from the type defined by the language. For example,
104 // in C++ the auto variables are in the default address space. Therefore
105 // cast alloca to the default address space when necessary.
107 auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
108 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
109 // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
110 // otherwise alloca is inserted at the current insertion point of the
111 // builder.
112 if (!ArraySize)
113 Builder.SetInsertPoint(getPostAllocaInsertPoint());
116 Builder.getPtrTy(DestAddrSpace), /*non-null*/ true);
117 }
118
119 return RawAddress(V, Ty, Align, KnownNonNull);
120}
121
122/// CreateTempAlloca - This creates an alloca and inserts it into the entry
123/// block if \p ArraySize is nullptr, otherwise inserts it at the current
124/// insertion point of the builder.
125llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
126 const Twine &Name,
127 llvm::Value *ArraySize) {
128 llvm::AllocaInst *Alloca;
129 if (ArraySize)
130 Alloca = Builder.CreateAlloca(Ty, ArraySize, Name);
131 else
132 Alloca =
133 new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
134 ArraySize, Name, AllocaInsertPt->getIterator());
135 if (Allocas) {
136 Allocas->Add(Alloca);
137 }
138 return Alloca;
139}
140
141/// CreateDefaultAlignTempAlloca - This creates an alloca with the
142/// default alignment of the corresponding LLVM type, which is *not*
143/// guaranteed to be related in any way to the expected alignment of
144/// an AST type that might have been lowered to Ty.
146 const Twine &Name) {
147 CharUnits Align =
148 CharUnits::fromQuantity(CGM.getDataLayout().getPrefTypeAlign(Ty));
149 return CreateTempAlloca(Ty, Align, Name);
150}
151
154 return CreateTempAlloca(ConvertType(Ty), Align, Name);
155}
156
158 RawAddress *Alloca) {
159 // FIXME: Should we prefer the preferred type alignment here?
160 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
161}
162
164 const Twine &Name,
165 RawAddress *Alloca) {
167 /*ArraySize=*/nullptr, Alloca);
168
169 if (Ty->isConstantMatrixType()) {
170 auto *ArrayTy = cast<llvm::ArrayType>(Result.getElementType());
171 auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
172 ArrayTy->getNumElements());
173
174 Result = Address(Result.getPointer(), VectorTy, Result.getAlignment(),
176 }
177 return Result;
178}
179
181 CharUnits Align,
182 const Twine &Name) {
183 return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
184}
185
187 const Twine &Name) {
188 return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
189 Name);
190}
191
192/// EvaluateExprAsBool - Perform the usual unary conversions on the specified
193/// expression and compare the result against zero, returning an Int1Ty value.
194llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
195 PGO.setCurrentStmt(E);
196 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
197 llvm::Value *MemPtr = EmitScalarExpr(E);
198 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
199 }
200
201 QualType BoolTy = getContext().BoolTy;
203 CGFPOptionsRAII FPOptsRAII(*this, E);
204 if (!E->getType()->isAnyComplexType())
205 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
206
208 Loc);
209}
210
211/// EmitIgnoredExpr - Emit code to compute the specified expression,
212/// ignoring the result.
214 if (E->isPRValue())
215 return (void)EmitAnyExpr(E, AggValueSlot::ignored(), true);
216
217 // if this is a bitfield-resulting conditional operator, we can special case
218 // emit this. The normal 'EmitLValue' version of this is particularly
219 // difficult to codegen for, since creating a single "LValue" for two
220 // different sized arguments here is not particularly doable.
221 if (const auto *CondOp = dyn_cast<AbstractConditionalOperator>(
223 if (CondOp->getObjectKind() == OK_BitField)
224 return EmitIgnoredConditionalOperator(CondOp);
225 }
226
227 // Just emit it as an l-value and drop the result.
228 EmitLValue(E);
229}
230
231/// EmitAnyExpr - Emit code to compute the specified expression which
232/// can have any type. The result is returned as an RValue struct.
233/// If this is an aggregate expression, AggSlot indicates where the
234/// result should be returned.
236 AggValueSlot aggSlot,
237 bool ignoreResult) {
238 switch (getEvaluationKind(E->getType())) {
239 case TEK_Scalar:
240 return RValue::get(EmitScalarExpr(E, ignoreResult));
241 case TEK_Complex:
242 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
243 case TEK_Aggregate:
244 if (!ignoreResult && aggSlot.isIgnored())
245 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
246 EmitAggExpr(E, aggSlot);
247 return aggSlot.asRValue();
248 }
249 llvm_unreachable("bad evaluation kind");
250}
251
252/// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
253/// always be accessible even if no aggregate location is provided.
256
258 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
259 return EmitAnyExpr(E, AggSlot);
260}
261
262/// EmitAnyExprToMem - Evaluate an expression into a given memory
263/// location.
265 Address Location,
266 Qualifiers Quals,
267 bool IsInit) {
268 // FIXME: This function should take an LValue as an argument.
269 switch (getEvaluationKind(E->getType())) {
270 case TEK_Complex:
272 /*isInit*/ false);
273 return;
274
275 case TEK_Aggregate: {
276 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
281 return;
282 }
283
284 case TEK_Scalar: {
285 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
286 LValue LV = MakeAddrLValue(Location, E->getType());
288 return;
289 }
290 }
291 llvm_unreachable("bad evaluation kind");
292}
293
295 const Expr *E, LValue LV, AggValueSlot::IsZeroed_t IsZeroed) {
296 QualType Type = LV.getType();
297 switch (getEvaluationKind(Type)) {
298 case TEK_Complex:
299 EmitComplexExprIntoLValue(E, LV, /*isInit*/ true);
300 return;
301 case TEK_Aggregate:
305 AggValueSlot::MayOverlap, IsZeroed));
306 return;
307 case TEK_Scalar:
308 if (LV.isSimple())
309 EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false);
310 else
312 return;
313 }
314 llvm_unreachable("bad evaluation kind");
315}
316
317static void
319 const Expr *E, Address ReferenceTemporary) {
320 // Objective-C++ ARC:
321 // If we are binding a reference to a temporary that has ownership, we
322 // need to perform retain/release operations on the temporary.
323 //
324 // FIXME: This should be looking at E, not M.
325 if (auto Lifetime = M->getType().getObjCLifetime()) {
326 switch (Lifetime) {
329 // Carry on to normal cleanup handling.
330 break;
331
333 // Nothing to do; cleaned up by an autorelease pool.
334 return;
335
338 switch (StorageDuration Duration = M->getStorageDuration()) {
339 case SD_Static:
340 // Note: we intentionally do not register a cleanup to release
341 // the object on program termination.
342 return;
343
344 case SD_Thread:
345 // FIXME: We should probably register a cleanup in this case.
346 return;
347
348 case SD_Automatic:
352 if (Lifetime == Qualifiers::OCL_Strong) {
353 const ValueDecl *VD = M->getExtendingDecl();
354 bool Precise = isa_and_nonnull<VarDecl>(VD) &&
355 VD->hasAttr<ObjCPreciseLifetimeAttr>();
359 } else {
360 // __weak objects always get EH cleanups; otherwise, exceptions
361 // could cause really nasty crashes instead of mere leaks.
364 }
365 if (Duration == SD_FullExpression)
366 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
367 M->getType(), *Destroy,
369 else
370 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
371 M->getType(),
372 *Destroy, CleanupKind & EHCleanup);
373 return;
374
375 case SD_Dynamic:
376 llvm_unreachable("temporary cannot have dynamic storage duration");
377 }
378 llvm_unreachable("unknown storage duration");
379 }
380 }
381
382 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
383 if (const RecordType *RT =
385 // Get the destructor for the reference temporary.
386 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
387 if (!ClassDecl->hasTrivialDestructor())
388 ReferenceTemporaryDtor = ClassDecl->getDestructor();
389 }
390
391 if (!ReferenceTemporaryDtor)
392 return;
393
394 // Call the destructor for the temporary.
395 switch (M->getStorageDuration()) {
396 case SD_Static:
397 case SD_Thread: {
398 llvm::FunctionCallee CleanupFn;
399 llvm::Constant *CleanupArg;
400 if (E->getType()->isArrayType()) {
402 ReferenceTemporary, E->getType(),
404 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
405 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
406 } else {
407 CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
408 GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
409 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.emitRawPointer(CGF));
410 }
412 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
413 break;
414 }
415
417 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
419 CGF.getLangOpts().Exceptions);
420 break;
421
422 case SD_Automatic:
424 ReferenceTemporary, E->getType(),
426 CGF.getLangOpts().Exceptions);
427 break;
428
429 case SD_Dynamic:
430 llvm_unreachable("temporary cannot have dynamic storage duration");
431 }
432}
433
436 const Expr *Inner,
437 RawAddress *Alloca = nullptr) {
438 auto &TCG = CGF.getTargetHooks();
439 switch (M->getStorageDuration()) {
441 case SD_Automatic: {
442 // If we have a constant temporary array or record try to promote it into a
443 // constant global under the same rules a normal constant would've been
444 // promoted. This is easier on the optimizer and generally emits fewer
445 // instructions.
446 QualType Ty = Inner->getType();
447 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
448 (Ty->isArrayType() || Ty->isRecordType()) &&
449 Ty.isConstantStorage(CGF.getContext(), true, false))
450 if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
451 auto AS = CGF.CGM.GetGlobalConstantAddressSpace();
452 auto *GV = new llvm::GlobalVariable(
453 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
454 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
455 llvm::GlobalValue::NotThreadLocal,
457 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
458 GV->setAlignment(alignment.getAsAlign());
459 llvm::Constant *C = GV;
460 if (AS != LangAS::Default)
461 C = TCG.performAddrSpaceCast(
462 CGF.CGM, GV, AS, LangAS::Default,
463 llvm::PointerType::get(
464 CGF.getLLVMContext(),
466 // FIXME: Should we put the new global into a COMDAT?
467 return RawAddress(C, GV->getValueType(), alignment);
468 }
469 return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
470 }
471 case SD_Thread:
472 case SD_Static:
473 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
474
475 case SD_Dynamic:
476 llvm_unreachable("temporary can't have dynamic storage duration");
477 }
478 llvm_unreachable("unknown storage duration");
479}
480
481/// Helper method to check if the underlying ABI is AAPCS
482static bool isAAPCS(const TargetInfo &TargetInfo) {
483 return TargetInfo.getABI().starts_with("aapcs");
484}
485
488 const Expr *E = M->getSubExpr();
489
490 assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
491 !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
492 "Reference should never be pseudo-strong!");
493
494 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
495 // as that will cause the lifetime adjustment to be lost for ARC
496 auto ownership = M->getType().getObjCLifetime();
497 if (ownership != Qualifiers::OCL_None &&
498 ownership != Qualifiers::OCL_ExplicitNone) {
500 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
501 llvm::Type *Ty = ConvertTypeForMem(E->getType());
502 Object = Object.withElementType(Ty);
503
504 // createReferenceTemporary will promote the temporary to a global with a
505 // constant initializer if it can. It can only do this to a value of
506 // ARC-manageable type if the value is global and therefore "immune" to
507 // ref-counting operations. Therefore we have no need to emit either a
508 // dynamic initialization or a cleanup and we can just return the address
509 // of the temporary.
510 if (Var->hasInitializer())
511 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
512
513 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
514 }
515 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
517
518 switch (getEvaluationKind(E->getType())) {
519 default: llvm_unreachable("expected scalar or aggregate expression");
520 case TEK_Scalar:
521 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
522 break;
523 case TEK_Aggregate: {
530 break;
531 }
532 }
533
534 pushTemporaryCleanup(*this, M, E, Object);
535 return RefTempDst;
536 }
537
540 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
541
542 for (const auto &Ignored : CommaLHSs)
543 EmitIgnoredExpr(Ignored);
544
545 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
546 if (opaque->getType()->isRecordType()) {
547 assert(Adjustments.empty());
548 return EmitOpaqueValueLValue(opaque);
549 }
550 }
551
552 // Create and initialize the reference temporary.
553 RawAddress Alloca = Address::invalid();
554 RawAddress Object = createReferenceTemporary(*this, M, E, &Alloca);
555 if (auto *Var = dyn_cast<llvm::GlobalVariable>(
556 Object.getPointer()->stripPointerCasts())) {
557 llvm::Type *TemporaryType = ConvertTypeForMem(E->getType());
558 Object = Object.withElementType(TemporaryType);
559 // If the temporary is a global and has a constant initializer or is a
560 // constant temporary that we promoted to a global, we may have already
561 // initialized it.
562 if (!Var->hasInitializer()) {
563 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
564 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
565 }
566 } else {
567 switch (M->getStorageDuration()) {
568 case SD_Automatic:
569 if (auto *Size = EmitLifetimeStart(
570 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
571 Alloca.getPointer())) {
572 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
573 Alloca, Size);
574 }
575 break;
576
577 case SD_FullExpression: {
578 if (!ShouldEmitLifetimeMarkers)
579 break;
580
581 // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
582 // marker. Instead, start the lifetime of a conditional temporary earlier
583 // so that it's unconditional. Don't do this with sanitizers which need
584 // more precise lifetime marks. However when inside an "await.suspend"
585 // block, we should always avoid conditional cleanup because it creates
586 // boolean marker that lives across await_suspend, which can destroy coro
587 // frame.
588 ConditionalEvaluation *OldConditional = nullptr;
589 CGBuilderTy::InsertPoint OldIP;
591 ((!SanOpts.has(SanitizerKind::HWAddress) &&
592 !SanOpts.has(SanitizerKind::Memory) &&
593 !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) ||
594 inSuspendBlock())) {
595 OldConditional = OutermostConditional;
596 OutermostConditional = nullptr;
597
598 OldIP = Builder.saveIP();
599 llvm::BasicBlock *Block = OldConditional->getStartingBlock();
600 Builder.restoreIP(CGBuilderTy::InsertPoint(
601 Block, llvm::BasicBlock::iterator(Block->back())));
602 }
603
604 if (auto *Size = EmitLifetimeStart(
605 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
606 Alloca.getPointer())) {
607 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
608 Size);
609 }
610
611 if (OldConditional) {
612 OutermostConditional = OldConditional;
613 Builder.restoreIP(OldIP);
614 }
615 break;
616 }
617
618 default:
619 break;
620 }
621 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
622 }
623 pushTemporaryCleanup(*this, M, E, Object);
624
625 // Perform derived-to-base casts and/or field accesses, to get from the
626 // temporary object we created (and, potentially, for which we extended
627 // the lifetime) to the subobject we're binding the reference to.
628 for (SubobjectAdjustment &Adjustment : llvm::reverse(Adjustments)) {
629 switch (Adjustment.Kind) {
631 Object =
632 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
633 Adjustment.DerivedToBase.BasePath->path_begin(),
634 Adjustment.DerivedToBase.BasePath->path_end(),
635 /*NullCheckValue=*/ false, E->getExprLoc());
636 break;
637
640 LV = EmitLValueForField(LV, Adjustment.Field);
641 assert(LV.isSimple() &&
642 "materialized temporary field is not a simple lvalue");
643 Object = LV.getAddress();
644 break;
645 }
646
648 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
650 Adjustment.Ptr.MPT);
651 break;
652 }
653 }
654 }
655
656 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
657}
658
659RValue
661 // Emit the expression as an lvalue.
662 LValue LV = EmitLValue(E);
663 assert(LV.isSimple());
664 llvm::Value *Value = LV.getPointer(*this);
665
667 // C++11 [dcl.ref]p5 (as amended by core issue 453):
668 // If a glvalue to which a reference is directly bound designates neither
669 // an existing object or function of an appropriate type nor a region of
670 // storage of suitable size and alignment to contain an object of the
671 // reference's type, the behavior is undefined.
672 QualType Ty = E->getType();
674 }
675
676 return RValue::get(Value);
677}
678
679
680/// getAccessedFieldNo - Given an encoded value and a result number, return the
681/// input field number being accessed.
682unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
683 const llvm::Constant *Elts) {
684 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
685 ->getZExtValue();
686}
687
688static llvm::Value *emitHashMix(CGBuilderTy &Builder, llvm::Value *Acc,
689 llvm::Value *Ptr) {
690 llvm::Value *A0 =
691 Builder.CreateMul(Ptr, Builder.getInt64(0xbf58476d1ce4e5b9u));
692 llvm::Value *A1 =
693 Builder.CreateXor(A0, Builder.CreateLShr(A0, Builder.getInt64(31)));
694 return Builder.CreateXor(Acc, A1);
695}
696
697bool CodeGenFunction::isNullPointerAllowed(TypeCheckKind TCK) {
698 return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
700}
701
702bool CodeGenFunction::isVptrCheckRequired(TypeCheckKind TCK, QualType Ty) {
704 return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
705 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
708}
709
711 return SanOpts.has(SanitizerKind::Null) ||
712 SanOpts.has(SanitizerKind::Alignment) ||
713 SanOpts.has(SanitizerKind::ObjectSize) ||
714 SanOpts.has(SanitizerKind::Vptr);
715}
716
718 llvm::Value *Ptr, QualType Ty,
719 CharUnits Alignment,
720 SanitizerSet SkippedChecks,
721 llvm::Value *ArraySize) {
723 return;
724
725 // Don't check pointers outside the default address space. The null check
726 // isn't correct, the object-size check isn't supported by LLVM, and we can't
727 // communicate the addresses to the runtime handler for the vptr check.
728 if (Ptr->getType()->getPointerAddressSpace())
729 return;
730
731 // Don't check pointers to volatile data. The behavior here is implementation-
732 // defined.
733 if (Ty.isVolatileQualified())
734 return;
735
736 SanitizerScope SanScope(this);
737
739 llvm::BasicBlock *Done = nullptr;
740
741 // Quickly determine whether we have a pointer to an alloca. It's possible
742 // to skip null checks, and some alignment checks, for these pointers. This
743 // can reduce compile-time significantly.
744 auto PtrToAlloca = dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCasts());
745
746 llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
747 llvm::Value *IsNonNull = nullptr;
748 bool IsGuaranteedNonNull =
749 SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
750 bool AllowNullPointers = isNullPointerAllowed(TCK);
751 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
752 !IsGuaranteedNonNull) {
753 // The glvalue must not be an empty glvalue.
754 IsNonNull = Builder.CreateIsNotNull(Ptr);
755
756 // The IR builder can constant-fold the null check if the pointer points to
757 // a constant.
758 IsGuaranteedNonNull = IsNonNull == True;
759
760 // Skip the null check if the pointer is known to be non-null.
761 if (!IsGuaranteedNonNull) {
762 if (AllowNullPointers) {
763 // When performing pointer casts, it's OK if the value is null.
764 // Skip the remaining checks in that case.
765 Done = createBasicBlock("null");
766 llvm::BasicBlock *Rest = createBasicBlock("not.null");
767 Builder.CreateCondBr(IsNonNull, Rest, Done);
768 EmitBlock(Rest);
769 } else {
770 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
771 }
772 }
773 }
774
775 if (SanOpts.has(SanitizerKind::ObjectSize) &&
776 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
777 !Ty->isIncompleteType()) {
779 llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
780 if (ArraySize)
781 Size = Builder.CreateMul(Size, ArraySize);
782
783 // Degenerate case: new X[0] does not need an objectsize check.
784 llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
785 if (!ConstantSize || !ConstantSize->isNullValue()) {
786 // The glvalue must refer to a large enough storage region.
787 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
788 // to check this.
789 // FIXME: Get object address space
790 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
791 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
792 llvm::Value *Min = Builder.getFalse();
793 llvm::Value *NullIsUnknown = Builder.getFalse();
794 llvm::Value *Dynamic = Builder.getFalse();
795 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
796 Builder.CreateCall(F, {Ptr, Min, NullIsUnknown, Dynamic}), Size);
797 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
798 }
799 }
800
801 llvm::MaybeAlign AlignVal;
802 llvm::Value *PtrAsInt = nullptr;
803
804 if (SanOpts.has(SanitizerKind::Alignment) &&
805 !SkippedChecks.has(SanitizerKind::Alignment)) {
806 AlignVal = Alignment.getAsMaybeAlign();
807 if (!Ty->isIncompleteType() && !AlignVal)
808 AlignVal = CGM.getNaturalTypeAlignment(Ty, nullptr, nullptr,
809 /*ForPointeeType=*/true)
811
812 // The glvalue must be suitably aligned.
813 if (AlignVal && *AlignVal > llvm::Align(1) &&
814 (!PtrToAlloca || PtrToAlloca->getAlign() < *AlignVal)) {
815 PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
816 llvm::Value *Align = Builder.CreateAnd(
817 PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal->value() - 1));
818 llvm::Value *Aligned =
819 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
820 if (Aligned != True)
821 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
822 }
823 }
824
825 if (Checks.size() > 0) {
826 llvm::Constant *StaticData[] = {
828 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2(*AlignVal) : 1),
829 llvm::ConstantInt::get(Int8Ty, TCK)};
830 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
831 PtrAsInt ? PtrAsInt : Ptr);
832 }
833
834 // If possible, check that the vptr indicates that there is a subobject of
835 // type Ty at offset zero within this object.
836 //
837 // C++11 [basic.life]p5,6:
838 // [For storage which does not refer to an object within its lifetime]
839 // The program has undefined behavior if:
840 // -- the [pointer or glvalue] is used to access a non-static data member
841 // or call a non-static member function
842 if (SanOpts.has(SanitizerKind::Vptr) &&
843 !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
844 // Ensure that the pointer is non-null before loading it. If there is no
845 // compile-time guarantee, reuse the run-time null check or emit a new one.
846 if (!IsGuaranteedNonNull) {
847 if (!IsNonNull)
848 IsNonNull = Builder.CreateIsNotNull(Ptr);
849 if (!Done)
850 Done = createBasicBlock("vptr.null");
851 llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
852 Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
853 EmitBlock(VptrNotNull);
854 }
855
856 // Compute a deterministic hash of the mangled name of the type.
857 SmallString<64> MangledName;
858 llvm::raw_svector_ostream Out(MangledName);
860 Out);
861
862 // Contained in NoSanitizeList based on the mangled type.
863 if (!CGM.getContext().getNoSanitizeList().containsType(SanitizerKind::Vptr,
864 Out.str())) {
865 // Load the vptr, and mix it with TypeHash.
866 llvm::Value *TypeHash =
867 llvm::ConstantInt::get(Int64Ty, xxh3_64bits(Out.str()));
868
869 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
870 Address VPtrAddr(Ptr, IntPtrTy, getPointerAlign());
871 llvm::Value *VPtrVal = GetVTablePtr(VPtrAddr, VPtrTy,
872 Ty->getAsCXXRecordDecl(),
874 VPtrVal = Builder.CreateBitOrPointerCast(VPtrVal, IntPtrTy);
875
876 llvm::Value *Hash =
877 emitHashMix(Builder, TypeHash, Builder.CreateZExt(VPtrVal, Int64Ty));
878 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
879
880 // Look the hash up in our cache.
881 const int CacheSize = 128;
882 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
883 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
884 "__ubsan_vptr_type_cache");
885 llvm::Value *Slot = Builder.CreateAnd(Hash,
886 llvm::ConstantInt::get(IntPtrTy,
887 CacheSize-1));
888 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
889 llvm::Value *CacheVal = Builder.CreateAlignedLoad(
890 IntPtrTy, Builder.CreateInBoundsGEP(HashTable, Cache, Indices),
892
893 // If the hash isn't in the cache, call a runtime handler to perform the
894 // hard work of checking whether the vptr is for an object of the right
895 // type. This will either fill in the cache and return, or produce a
896 // diagnostic.
897 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
898 llvm::Constant *StaticData[] = {
902 llvm::ConstantInt::get(Int8Ty, TCK)
903 };
904 llvm::Value *DynamicData[] = { Ptr, Hash };
905 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
906 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
907 DynamicData);
908 }
909 }
910
911 if (Done) {
912 Builder.CreateBr(Done);
913 EmitBlock(Done);
914 }
915}
916
918 QualType EltTy) {
920 uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
921 if (!EltSize)
922 return nullptr;
923
924 auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
925 if (!ArrayDeclRef)
926 return nullptr;
927
928 auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
929 if (!ParamDecl)
930 return nullptr;
931
932 auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
933 if (!POSAttr)
934 return nullptr;
935
936 // Don't load the size if it's a lower bound.
937 int POSType = POSAttr->getType();
938 if (POSType != 0 && POSType != 1)
939 return nullptr;
940
941 // Find the implicit size parameter.
942 auto PassedSizeIt = SizeArguments.find(ParamDecl);
943 if (PassedSizeIt == SizeArguments.end())
944 return nullptr;
945
946 const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
947 assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
948 Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
949 llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
950 C.getSizeType(), E->getExprLoc());
951 llvm::Value *SizeOfElement =
952 llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
953 return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
954}
955
956/// If Base is known to point to the start of an array, return the length of
957/// that array. Return 0 if the length cannot be determined.
958static llvm::Value *getArrayIndexingBound(CodeGenFunction &CGF,
959 const Expr *Base,
960 QualType &IndexedType,
962 StrictFlexArraysLevel) {
963 // For the vector indexing extension, the bound is the number of elements.
964 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
965 IndexedType = Base->getType();
966 return CGF.Builder.getInt32(VT->getNumElements());
967 }
968
969 Base = Base->IgnoreParens();
970
971 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
972 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
973 !CE->getSubExpr()->isFlexibleArrayMemberLike(CGF.getContext(),
974 StrictFlexArraysLevel)) {
975 CodeGenFunction::SanitizerScope SanScope(&CGF);
976
977 IndexedType = CE->getSubExpr()->getType();
978 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
979 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
980 return CGF.Builder.getInt(CAT->getSize());
981
982 if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
983 return CGF.getVLASize(VAT).NumElts;
984 // Ignore pass_object_size here. It's not applicable on decayed pointers.
985 }
986 }
987
988 CodeGenFunction::SanitizerScope SanScope(&CGF);
989
990 QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
991 if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
992 IndexedType = Base->getType();
993 return POS;
994 }
995
996 return nullptr;
997}
998
999namespace {
1000
1001/// \p StructAccessBase returns the base \p Expr of a field access. It returns
1002/// either a \p DeclRefExpr, representing the base pointer to the struct, i.e.:
1003///
1004/// p in p-> a.b.c
1005///
1006/// or a \p MemberExpr, if the \p MemberExpr has the \p RecordDecl we're
1007/// looking for:
1008///
1009/// struct s {
1010/// struct s *ptr;
1011/// int count;
1012/// char array[] __attribute__((counted_by(count)));
1013/// };
1014///
1015/// If we have an expression like \p p->ptr->array[index], we want the
1016/// \p MemberExpr for \p p->ptr instead of \p p.
1017class StructAccessBase
1018 : public ConstStmtVisitor<StructAccessBase, const Expr *> {
1019 const RecordDecl *ExpectedRD;
1020
1021 bool IsExpectedRecordDecl(const Expr *E) const {
1022 QualType Ty = E->getType();
1023 if (Ty->isPointerType())
1024 Ty = Ty->getPointeeType();
1025 return ExpectedRD == Ty->getAsRecordDecl();
1026 }
1027
1028public:
1029 StructAccessBase(const RecordDecl *ExpectedRD) : ExpectedRD(ExpectedRD) {}
1030
1031 //===--------------------------------------------------------------------===//
1032 // Visitor Methods
1033 //===--------------------------------------------------------------------===//
1034
1035 // NOTE: If we build C++ support for counted_by, then we'll have to handle
1036 // horrors like this:
1037 //
1038 // struct S {
1039 // int x, y;
1040 // int blah[] __attribute__((counted_by(x)));
1041 // } s;
1042 //
1043 // int foo(int index, int val) {
1044 // int (S::*IHatePMDs)[] = &S::blah;
1045 // (s.*IHatePMDs)[index] = val;
1046 // }
1047
1048 const Expr *Visit(const Expr *E) {
1050 }
1051
1052 const Expr *VisitStmt(const Stmt *S) { return nullptr; }
1053
1054 // These are the types we expect to return (in order of most to least
1055 // likely):
1056 //
1057 // 1. DeclRefExpr - This is the expression for the base of the structure.
1058 // It's exactly what we want to build an access to the \p counted_by
1059 // field.
1060 // 2. MemberExpr - This is the expression that has the same \p RecordDecl
1061 // as the flexble array member's lexical enclosing \p RecordDecl. This
1062 // allows us to catch things like: "p->p->array"
1063 // 3. CompoundLiteralExpr - This is for people who create something
1064 // heretical like (struct foo has a flexible array member):
1065 //
1066 // (struct foo){ 1, 2 }.blah[idx];
1067 const Expr *VisitDeclRefExpr(const DeclRefExpr *E) {
1068 return IsExpectedRecordDecl(E) ? E : nullptr;
1069 }
1070 const Expr *VisitMemberExpr(const MemberExpr *E) {
1071 if (IsExpectedRecordDecl(E) && E->isArrow())
1072 return E;
1073 const Expr *Res = Visit(E->getBase());
1074 return !Res && IsExpectedRecordDecl(E) ? E : Res;
1075 }
1076 const Expr *VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1077 return IsExpectedRecordDecl(E) ? E : nullptr;
1078 }
1079 const Expr *VisitCallExpr(const CallExpr *E) {
1080 return IsExpectedRecordDecl(E) ? E : nullptr;
1081 }
1082
1083 const Expr *VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1084 if (IsExpectedRecordDecl(E))
1085 return E;
1086 return Visit(E->getBase());
1087 }
1088 const Expr *VisitCastExpr(const CastExpr *E) {
1089 if (E->getCastKind() == CK_LValueToRValue)
1090 return IsExpectedRecordDecl(E) ? E : nullptr;
1091 return Visit(E->getSubExpr());
1092 }
1093 const Expr *VisitParenExpr(const ParenExpr *E) {
1094 return Visit(E->getSubExpr());
1095 }
1096 const Expr *VisitUnaryAddrOf(const UnaryOperator *E) {
1097 return Visit(E->getSubExpr());
1098 }
1099 const Expr *VisitUnaryDeref(const UnaryOperator *E) {
1100 return Visit(E->getSubExpr());
1101 }
1102};
1103
1104} // end anonymous namespace
1105
1107
1109 const FieldDecl *Field,
1110 RecIndicesTy &Indices) {
1111 const CGRecordLayout &Layout = CGF.CGM.getTypes().getCGRecordLayout(RD);
1112 int64_t FieldNo = -1;
1113 for (const FieldDecl *FD : RD->fields()) {
1114 if (!Layout.containsFieldDecl(FD))
1115 // This could happen if the field has a struct type that's empty. I don't
1116 // know why either.
1117 continue;
1118
1119 FieldNo = Layout.getLLVMFieldNo(FD);
1120 if (FD == Field) {
1121 Indices.emplace_back(CGF.Builder.getInt32(FieldNo));
1122 return true;
1123 }
1124
1125 QualType Ty = FD->getType();
1126 if (Ty->isRecordType()) {
1127 if (getGEPIndicesToField(CGF, Ty->getAsRecordDecl(), Field, Indices)) {
1128 if (RD->isUnion())
1129 FieldNo = 0;
1130 Indices.emplace_back(CGF.Builder.getInt32(FieldNo));
1131 return true;
1132 }
1133 }
1134 }
1135
1136 return false;
1137}
1138
1140 const Expr *Base, const FieldDecl *FAMDecl, const FieldDecl *CountDecl) {
1141 const RecordDecl *RD = CountDecl->getParent()->getOuterLexicalRecordContext();
1142
1143 // Find the base struct expr (i.e. p in p->a.b.c.d).
1144 const Expr *StructBase = StructAccessBase(RD).Visit(Base);
1145 if (!StructBase || StructBase->HasSideEffects(getContext()))
1146 return nullptr;
1147
1148 llvm::Value *Res = nullptr;
1149 if (StructBase->getType()->isPointerType()) {
1150 LValueBaseInfo BaseInfo;
1151 TBAAAccessInfo TBAAInfo;
1152 Address Addr = EmitPointerWithAlignment(StructBase, &BaseInfo, &TBAAInfo);
1153 Res = Addr.emitRawPointer(*this);
1154 } else if (StructBase->isLValue()) {
1155 LValue LV = EmitLValue(StructBase);
1156 Address Addr = LV.getAddress();
1157 Res = Addr.emitRawPointer(*this);
1158 } else {
1159 return nullptr;
1160 }
1161
1162 RecIndicesTy Indices;
1163 getGEPIndicesToField(*this, RD, CountDecl, Indices);
1164 if (Indices.empty())
1165 return nullptr;
1166
1167 Indices.push_back(Builder.getInt32(0));
1169 ConvertType(QualType(RD->getTypeForDecl(), 0)), Res,
1170 RecIndicesTy(llvm::reverse(Indices)), "counted_by.gep");
1171}
1172
1173/// This method is typically called in contexts where we can't generate
1174/// side-effects, like in __builtin_dynamic_object_size. When finding
1175/// expressions, only choose those that have either already been emitted or can
1176/// be loaded without side-effects.
1177///
1178/// - \p FAMDecl: the \p Decl for the flexible array member. It may not be
1179/// within the top-level struct.
1180/// - \p CountDecl: must be within the same non-anonymous struct as \p FAMDecl.
1182 const Expr *Base, const FieldDecl *FAMDecl, const FieldDecl *CountDecl) {
1183 if (llvm::Value *GEP = GetCountedByFieldExprGEP(Base, FAMDecl, CountDecl))
1184 return Builder.CreateAlignedLoad(ConvertType(CountDecl->getType()), GEP,
1185 getIntAlign(), "counted_by.load");
1186 return nullptr;
1187}
1188
1189void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
1190 llvm::Value *Index, QualType IndexType,
1191 bool Accessed) {
1192 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
1193 "should not be called unless adding bounds checks");
1194 const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
1195 getLangOpts().getStrictFlexArraysLevel();
1196 QualType IndexedType;
1197 llvm::Value *Bound =
1198 getArrayIndexingBound(*this, Base, IndexedType, StrictFlexArraysLevel);
1199
1200 EmitBoundsCheckImpl(E, Bound, Index, IndexType, IndexedType, Accessed);
1201}
1202
1203void CodeGenFunction::EmitBoundsCheckImpl(const Expr *E, llvm::Value *Bound,
1204 llvm::Value *Index,
1205 QualType IndexType,
1206 QualType IndexedType, bool Accessed) {
1207 if (!Bound)
1208 return;
1209
1210 SanitizerScope SanScope(this);
1211
1212 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
1213 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
1214 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
1215
1216 llvm::Constant *StaticData[] = {
1218 EmitCheckTypeDescriptor(IndexedType),
1219 EmitCheckTypeDescriptor(IndexType)
1220 };
1221 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
1222 : Builder.CreateICmpULE(IndexVal, BoundVal);
1223 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
1224 SanitizerHandler::OutOfBounds, StaticData, Index);
1225}
1226
1229 bool isInc, bool isPre) {
1231
1232 llvm::Value *NextVal;
1233 if (isa<llvm::IntegerType>(InVal.first->getType())) {
1234 uint64_t AmountVal = isInc ? 1 : -1;
1235 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
1236
1237 // Add the inc/dec to the real part.
1238 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1239 } else {
1240 QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
1241 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1242 if (!isInc)
1243 FVal.changeSign();
1244 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1245
1246 // Add the inc/dec to the real part.
1247 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1248 }
1249
1250 ComplexPairTy IncVal(NextVal, InVal.second);
1251
1252 // Store the updated result through the lvalue.
1253 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1254 if (getLangOpts().OpenMP)
1256 E->getSubExpr());
1257
1258 // If this is a postinc, return the value read from memory, otherwise use the
1259 // updated value.
1260 return isPre ? IncVal : InVal;
1261}
1262
1264 CodeGenFunction *CGF) {
1265 // Bind VLAs in the cast type.
1266 if (CGF && E->getType()->isVariablyModifiedType())
1268
1269 if (CGDebugInfo *DI = getModuleDebugInfo())
1270 DI->EmitExplicitCastType(E->getType());
1271}
1272
1273//===----------------------------------------------------------------------===//
1274// LValue Expression Emission
1275//===----------------------------------------------------------------------===//
1276
1278 TBAAAccessInfo *TBAAInfo,
1279 KnownNonNull_t IsKnownNonNull,
1280 CodeGenFunction &CGF) {
1281 // We allow this with ObjC object pointers because of fragile ABIs.
1282 assert(E->getType()->isPointerType() ||
1284 E = E->IgnoreParens();
1285
1286 // Casts:
1287 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1288 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1289 CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
1290
1291 switch (CE->getCastKind()) {
1292 // Non-converting casts (but not C's implicit conversion from void*).
1293 case CK_BitCast:
1294 case CK_NoOp:
1295 case CK_AddressSpaceConversion:
1296 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1297 if (PtrTy->getPointeeType()->isVoidType())
1298 break;
1299
1300 LValueBaseInfo InnerBaseInfo;
1301 TBAAAccessInfo InnerTBAAInfo;
1303 CE->getSubExpr(), &InnerBaseInfo, &InnerTBAAInfo, IsKnownNonNull);
1304 if (BaseInfo) *BaseInfo = InnerBaseInfo;
1305 if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1306
1307 if (isa<ExplicitCastExpr>(CE)) {
1308 LValueBaseInfo TargetTypeBaseInfo;
1309 TBAAAccessInfo TargetTypeTBAAInfo;
1311 E->getType(), &TargetTypeBaseInfo, &TargetTypeTBAAInfo);
1312 if (TBAAInfo)
1313 *TBAAInfo =
1314 CGF.CGM.mergeTBAAInfoForCast(*TBAAInfo, TargetTypeTBAAInfo);
1315 // If the source l-value is opaque, honor the alignment of the
1316 // casted-to type.
1317 if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1318 if (BaseInfo)
1319 BaseInfo->mergeForCast(TargetTypeBaseInfo);
1320 Addr.setAlignment(Align);
1321 }
1322 }
1323
1324 if (CGF.SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1325 CE->getCastKind() == CK_BitCast) {
1326 if (auto PT = E->getType()->getAs<PointerType>())
1327 CGF.EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr,
1328 /*MayBeNull=*/true,
1330 CE->getBeginLoc());
1331 }
1332
1333 llvm::Type *ElemTy =
1335 Addr = Addr.withElementType(ElemTy);
1336 if (CE->getCastKind() == CK_AddressSpaceConversion)
1337 Addr = CGF.Builder.CreateAddrSpaceCast(
1338 Addr, CGF.ConvertType(E->getType()), ElemTy);
1339 return CGF.authPointerToPointerCast(Addr, CE->getSubExpr()->getType(),
1340 CE->getType());
1341 }
1342 break;
1343
1344 // Array-to-pointer decay.
1345 case CK_ArrayToPointerDecay:
1346 return CGF.EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1347
1348 // Derived-to-base conversions.
1349 case CK_UncheckedDerivedToBase:
1350 case CK_DerivedToBase: {
1351 // TODO: Support accesses to members of base classes in TBAA. For now, we
1352 // conservatively pretend that the complete object is of the base class
1353 // type.
1354 if (TBAAInfo)
1355 *TBAAInfo = CGF.CGM.getTBAAAccessInfo(E->getType());
1357 CE->getSubExpr(), BaseInfo, nullptr,
1358 (KnownNonNull_t)(IsKnownNonNull ||
1359 CE->getCastKind() == CK_UncheckedDerivedToBase));
1360 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1361 return CGF.GetAddressOfBaseClass(
1362 Addr, Derived, CE->path_begin(), CE->path_end(),
1363 CGF.ShouldNullCheckClassCastValue(CE), CE->getExprLoc());
1364 }
1365
1366 // TODO: Is there any reason to treat base-to-derived conversions
1367 // specially?
1368 default:
1369 break;
1370 }
1371 }
1372
1373 // Unary &.
1374 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1375 if (UO->getOpcode() == UO_AddrOf) {
1376 LValue LV = CGF.EmitLValue(UO->getSubExpr(), IsKnownNonNull);
1377 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1378 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1379 return LV.getAddress();
1380 }
1381 }
1382
1383 // std::addressof and variants.
1384 if (auto *Call = dyn_cast<CallExpr>(E)) {
1385 switch (Call->getBuiltinCallee()) {
1386 default:
1387 break;
1388 case Builtin::BIaddressof:
1389 case Builtin::BI__addressof:
1390 case Builtin::BI__builtin_addressof: {
1391 LValue LV = CGF.EmitLValue(Call->getArg(0), IsKnownNonNull);
1392 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1393 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1394 return LV.getAddress();
1395 }
1396 }
1397 }
1398
1399 // TODO: conditional operators, comma.
1400
1401 // Otherwise, use the alignment of the type.
1404 /*ForPointeeType=*/true, BaseInfo, TBAAInfo, IsKnownNonNull);
1405}
1406
1407/// EmitPointerWithAlignment - Given an expression of pointer type, try to
1408/// derive a more accurate bound on the alignment of the pointer.
1410 const Expr *E, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo,
1411 KnownNonNull_t IsKnownNonNull) {
1412 Address Addr =
1413 ::EmitPointerWithAlignment(E, BaseInfo, TBAAInfo, IsKnownNonNull, *this);
1414 if (IsKnownNonNull && !Addr.isKnownNonNull())
1415 Addr.setKnownNonNull();
1416 return Addr;
1417}
1418
1420 llvm::Value *V = RV.getScalarVal();
1421 if (auto MPT = T->getAs<MemberPointerType>())
1422 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, V, MPT);
1423 return Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType()));
1424}
1425
1427 if (Ty->isVoidType())
1428 return RValue::get(nullptr);
1429
1430 switch (getEvaluationKind(Ty)) {
1431 case TEK_Complex: {
1432 llvm::Type *EltTy =
1434 llvm::Value *U = llvm::UndefValue::get(EltTy);
1435 return RValue::getComplex(std::make_pair(U, U));
1436 }
1437
1438 // If this is a use of an undefined aggregate type, the aggregate must have an
1439 // identifiable address. Just because the contents of the value are undefined
1440 // doesn't mean that the address can't be taken and compared.
1441 case TEK_Aggregate: {
1442 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1443 return RValue::getAggregate(DestPtr);
1444 }
1445
1446 case TEK_Scalar:
1447 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1448 }
1449 llvm_unreachable("bad evaluation kind");
1450}
1451
1453 const char *Name) {
1454 ErrorUnsupported(E, Name);
1455 return GetUndefRValue(E->getType());
1456}
1457
1459 const char *Name) {
1460 ErrorUnsupported(E, Name);
1461 llvm::Type *ElTy = ConvertType(E->getType());
1462 llvm::Type *Ty = UnqualPtrTy;
1463 return MakeAddrLValue(
1464 Address(llvm::UndefValue::get(Ty), ElTy, CharUnits::One()), E->getType());
1465}
1466
1467bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
1468 const Expr *Base = Obj;
1469 while (!isa<CXXThisExpr>(Base)) {
1470 // The result of a dynamic_cast can be null.
1471 if (isa<CXXDynamicCastExpr>(Base))
1472 return false;
1473
1474 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1475 Base = CE->getSubExpr();
1476 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1477 Base = PE->getSubExpr();
1478 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1479 if (UO->getOpcode() == UO_Extension)
1480 Base = UO->getSubExpr();
1481 else
1482 return false;
1483 } else {
1484 return false;
1485 }
1486 }
1487 return true;
1488}
1489
1490LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1491 LValue LV;
1492 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1493 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1494 else
1495 LV = EmitLValue(E);
1496 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1497 SanitizerSet SkippedChecks;
1498 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1499 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1500 if (IsBaseCXXThis)
1501 SkippedChecks.set(SanitizerKind::Alignment, true);
1502 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1503 SkippedChecks.set(SanitizerKind::Null, true);
1504 }
1505 EmitTypeCheck(TCK, E->getExprLoc(), LV, E->getType(), SkippedChecks);
1506 }
1507 return LV;
1508}
1509
1510/// EmitLValue - Emit code to compute a designator that specifies the location
1511/// of the expression.
1512///
1513/// This can return one of two things: a simple address or a bitfield reference.
1514/// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1515/// an LLVM pointer type.
1516///
1517/// If this returns a bitfield reference, nothing about the pointee type of the
1518/// LLVM value is known: For example, it may not be a pointer to an integer.
1519///
1520/// If this returns a normal address, and if the lvalue's C type is fixed size,
1521/// this method guarantees that the returned pointer type will point to an LLVM
1522/// type of the same size of the lvalue's type. If the lvalue has a variable
1523/// length type, this is not possible.
1524///
1526 KnownNonNull_t IsKnownNonNull) {
1527 // Running with sufficient stack space to avoid deeply nested expressions
1528 // cause a stack overflow.
1529 LValue LV;
1531 E->getExprLoc(), [&] { LV = EmitLValueHelper(E, IsKnownNonNull); });
1532
1533 if (IsKnownNonNull && !LV.isKnownNonNull())
1534 LV.setKnownNonNull();
1535 return LV;
1536}
1537
1539 const ASTContext &Ctx) {
1540 const Expr *SE = E->getSubExpr()->IgnoreImplicit();
1541 if (isa<OpaqueValueExpr>(SE))
1542 return SE->getType();
1543 return cast<CallExpr>(SE)->getCallReturnType(Ctx)->getPointeeType();
1544}
1545
1546LValue CodeGenFunction::EmitLValueHelper(const Expr *E,
1547 KnownNonNull_t IsKnownNonNull) {
1548 ApplyDebugLocation DL(*this, E);
1549 switch (E->getStmtClass()) {
1550 default: return EmitUnsupportedLValue(E, "l-value expression");
1551
1552 case Expr::ObjCPropertyRefExprClass:
1553 llvm_unreachable("cannot emit a property reference directly");
1554
1555 case Expr::ObjCSelectorExprClass:
1556 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1557 case Expr::ObjCIsaExprClass:
1558 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1559 case Expr::BinaryOperatorClass:
1560 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1561 case Expr::CompoundAssignOperatorClass: {
1562 QualType Ty = E->getType();
1563 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1564 Ty = AT->getValueType();
1565 if (!Ty->isAnyComplexType())
1566 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1567 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1568 }
1569 case Expr::CallExprClass:
1570 case Expr::CXXMemberCallExprClass:
1571 case Expr::CXXOperatorCallExprClass:
1572 case Expr::UserDefinedLiteralClass:
1573 return EmitCallExprLValue(cast<CallExpr>(E));
1574 case Expr::CXXRewrittenBinaryOperatorClass:
1575 return EmitLValue(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm(),
1576 IsKnownNonNull);
1577 case Expr::VAArgExprClass:
1578 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1579 case Expr::DeclRefExprClass:
1580 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1581 case Expr::ConstantExprClass: {
1582 const ConstantExpr *CE = cast<ConstantExpr>(E);
1583 if (llvm::Value *Result = ConstantEmitter(*this).tryEmitConstantExpr(CE)) {
1585 return MakeNaturalAlignAddrLValue(Result, RetType);
1586 }
1587 return EmitLValue(cast<ConstantExpr>(E)->getSubExpr(), IsKnownNonNull);
1588 }
1589 case Expr::ParenExprClass:
1590 return EmitLValue(cast<ParenExpr>(E)->getSubExpr(), IsKnownNonNull);
1591 case Expr::GenericSelectionExprClass:
1592 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr(),
1593 IsKnownNonNull);
1594 case Expr::PredefinedExprClass:
1595 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1596 case Expr::StringLiteralClass:
1597 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1598 case Expr::ObjCEncodeExprClass:
1599 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1600 case Expr::PseudoObjectExprClass:
1601 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1602 case Expr::InitListExprClass:
1603 return EmitInitListLValue(cast<InitListExpr>(E));
1604 case Expr::CXXTemporaryObjectExprClass:
1605 case Expr::CXXConstructExprClass:
1606 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1607 case Expr::CXXBindTemporaryExprClass:
1608 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1609 case Expr::CXXUuidofExprClass:
1610 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1611 case Expr::LambdaExprClass:
1612 return EmitAggExprToLValue(E);
1613
1614 case Expr::ExprWithCleanupsClass: {
1615 const auto *cleanups = cast<ExprWithCleanups>(E);
1616 RunCleanupsScope Scope(*this);
1617 LValue LV = EmitLValue(cleanups->getSubExpr(), IsKnownNonNull);
1618 if (LV.isSimple()) {
1619 // Defend against branches out of gnu statement expressions surrounded by
1620 // cleanups.
1621 Address Addr = LV.getAddress();
1622 llvm::Value *V = Addr.getBasePointer();
1623 Scope.ForceCleanup({&V});
1624 Addr.replaceBasePointer(V);
1625 return LValue::MakeAddr(Addr, LV.getType(), getContext(),
1626 LV.getBaseInfo(), LV.getTBAAInfo());
1627 }
1628 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1629 // bitfield lvalue or some other non-simple lvalue?
1630 return LV;
1631 }
1632
1633 case Expr::CXXDefaultArgExprClass: {
1634 auto *DAE = cast<CXXDefaultArgExpr>(E);
1635 CXXDefaultArgExprScope Scope(*this, DAE);
1636 return EmitLValue(DAE->getExpr(), IsKnownNonNull);
1637 }
1638 case Expr::CXXDefaultInitExprClass: {
1639 auto *DIE = cast<CXXDefaultInitExpr>(E);
1640 CXXDefaultInitExprScope Scope(*this, DIE);
1641 return EmitLValue(DIE->getExpr(), IsKnownNonNull);
1642 }
1643 case Expr::CXXTypeidExprClass:
1644 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1645
1646 case Expr::ObjCMessageExprClass:
1647 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1648 case Expr::ObjCIvarRefExprClass:
1649 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1650 case Expr::StmtExprClass:
1651 return EmitStmtExprLValue(cast<StmtExpr>(E));
1652 case Expr::UnaryOperatorClass:
1653 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1654 case Expr::ArraySubscriptExprClass:
1655 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1656 case Expr::MatrixSubscriptExprClass:
1657 return EmitMatrixSubscriptExpr(cast<MatrixSubscriptExpr>(E));
1658 case Expr::ArraySectionExprClass:
1659 return EmitArraySectionExpr(cast<ArraySectionExpr>(E));
1660 case Expr::ExtVectorElementExprClass:
1661 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1662 case Expr::CXXThisExprClass:
1664 case Expr::MemberExprClass:
1665 return EmitMemberExpr(cast<MemberExpr>(E));
1666 case Expr::CompoundLiteralExprClass:
1667 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1668 case Expr::ConditionalOperatorClass:
1669 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1670 case Expr::BinaryConditionalOperatorClass:
1671 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1672 case Expr::ChooseExprClass:
1673 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(), IsKnownNonNull);
1674 case Expr::OpaqueValueExprClass:
1675 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1676 case Expr::SubstNonTypeTemplateParmExprClass:
1677 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(),
1678 IsKnownNonNull);
1679 case Expr::ImplicitCastExprClass:
1680 case Expr::CStyleCastExprClass:
1681 case Expr::CXXFunctionalCastExprClass:
1682 case Expr::CXXStaticCastExprClass:
1683 case Expr::CXXDynamicCastExprClass:
1684 case Expr::CXXReinterpretCastExprClass:
1685 case Expr::CXXConstCastExprClass:
1686 case Expr::CXXAddrspaceCastExprClass:
1687 case Expr::ObjCBridgedCastExprClass:
1688 return EmitCastLValue(cast<CastExpr>(E));
1689
1690 case Expr::MaterializeTemporaryExprClass:
1691 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1692
1693 case Expr::CoawaitExprClass:
1694 return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1695 case Expr::CoyieldExprClass:
1696 return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1697 case Expr::PackIndexingExprClass:
1698 return EmitLValue(cast<PackIndexingExpr>(E)->getSelectedExpr());
1699 case Expr::HLSLOutArgExprClass:
1700 llvm_unreachable("cannot emit a HLSL out argument directly");
1701 }
1702}
1703
1704/// Given an object of the given canonical type, can we safely copy a
1705/// value out of it based on its initializer?
1707 assert(type.isCanonical());
1708 assert(!type->isReferenceType());
1709
1710 // Must be const-qualified but non-volatile.
1711 Qualifiers qs = type.getLocalQualifiers();
1712 if (!qs.hasConst() || qs.hasVolatile()) return false;
1713
1714 // Otherwise, all object types satisfy this except C++ classes with
1715 // mutable subobjects or non-trivial copy/destroy behavior.
1716 if (const auto *RT = dyn_cast<RecordType>(type))
1717 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1718 if (RD->hasMutableFields() || !RD->isTrivial())
1719 return false;
1720
1721 return true;
1722}
1723
1724/// Can we constant-emit a load of a reference to a variable of the
1725/// given type? This is different from predicates like
1726/// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1727/// in situations that don't necessarily satisfy the language's rules
1728/// for this (e.g. C++'s ODR-use rules). For example, we want to able
1729/// to do this with const float variables even if those variables
1730/// aren't marked 'constexpr'.
1738 type = type.getCanonicalType();
1739 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1740 if (isConstantEmittableObjectType(ref->getPointeeType()))
1742 return CEK_AsReferenceOnly;
1743 }
1745 return CEK_AsValueOnly;
1746 return CEK_None;
1747}
1748
1749/// Try to emit a reference to the given value without producing it as
1750/// an l-value. This is just an optimization, but it avoids us needing
1751/// to emit global copies of variables if they're named without triggering
1752/// a formal use in a context where we can't emit a direct reference to them,
1753/// for instance if a block or lambda or a member of a local class uses a
1754/// const int variable or constexpr variable from an enclosing function.
1755CodeGenFunction::ConstantEmission
1757 ValueDecl *value = refExpr->getDecl();
1758
1759 // The value needs to be an enum constant or a constant variable.
1761 if (isa<ParmVarDecl>(value)) {
1762 CEK = CEK_None;
1763 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1764 CEK = checkVarTypeForConstantEmission(var->getType());
1765 } else if (isa<EnumConstantDecl>(value)) {
1766 CEK = CEK_AsValueOnly;
1767 } else {
1768 CEK = CEK_None;
1769 }
1770 if (CEK == CEK_None) return ConstantEmission();
1771
1772 Expr::EvalResult result;
1773 bool resultIsReference;
1774 QualType resultType;
1775
1776 // It's best to evaluate all the way as an r-value if that's permitted.
1777 if (CEK != CEK_AsReferenceOnly &&
1778 refExpr->EvaluateAsRValue(result, getContext())) {
1779 resultIsReference = false;
1780 resultType = refExpr->getType();
1781
1782 // Otherwise, try to evaluate as an l-value.
1783 } else if (CEK != CEK_AsValueOnly &&
1784 refExpr->EvaluateAsLValue(result, getContext())) {
1785 resultIsReference = true;
1786 resultType = value->getType();
1787
1788 // Failure.
1789 } else {
1790 return ConstantEmission();
1791 }
1792
1793 // In any case, if the initializer has side-effects, abandon ship.
1794 if (result.HasSideEffects)
1795 return ConstantEmission();
1796
1797 // In CUDA/HIP device compilation, a lambda may capture a reference variable
1798 // referencing a global host variable by copy. In this case the lambda should
1799 // make a copy of the value of the global host variable. The DRE of the
1800 // captured reference variable cannot be emitted as load from the host
1801 // global variable as compile time constant, since the host variable is not
1802 // accessible on device. The DRE of the captured reference variable has to be
1803 // loaded from captures.
1804 if (CGM.getLangOpts().CUDAIsDevice && result.Val.isLValue() &&
1806 auto *MD = dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl);
1807 if (MD && MD->getParent()->isLambda() &&
1808 MD->getOverloadedOperator() == OO_Call) {
1809 const APValue::LValueBase &base = result.Val.getLValueBase();
1810 if (const ValueDecl *D = base.dyn_cast<const ValueDecl *>()) {
1811 if (const VarDecl *VD = dyn_cast<const VarDecl>(D)) {
1812 if (!VD->hasAttr<CUDADeviceAttr>()) {
1813 return ConstantEmission();
1814 }
1815 }
1816 }
1817 }
1818 }
1819
1820 // Emit as a constant.
1821 auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1822 result.Val, resultType);
1823
1824 // Make sure we emit a debug reference to the global variable.
1825 // This should probably fire even for
1826 if (isa<VarDecl>(value)) {
1827 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1828 EmitDeclRefExprDbgValue(refExpr, result.Val);
1829 } else {
1830 assert(isa<EnumConstantDecl>(value));
1831 EmitDeclRefExprDbgValue(refExpr, result.Val);
1832 }
1833
1834 // If we emitted a reference constant, we need to dereference that.
1835 if (resultIsReference)
1837
1839}
1840
1842 const MemberExpr *ME) {
1843 if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1844 // Try to emit static variable member expressions as DREs.
1845 return DeclRefExpr::Create(
1847 /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1848 ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1849 }
1850 return nullptr;
1851}
1852
1853CodeGenFunction::ConstantEmission
1856 return tryEmitAsConstant(DRE);
1857 return ConstantEmission();
1858}
1859
1861 const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1862 assert(Constant && "not a constant");
1863 if (Constant.isReference())
1864 return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1865 E->getExprLoc())
1866 .getScalarVal();
1867 return Constant.getValue();
1868}
1869
1870llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1872 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1873 lvalue.getType(), Loc, lvalue.getBaseInfo(),
1874 lvalue.getTBAAInfo(), lvalue.isNontemporal());
1875}
1876
1878 if (Ty->isBooleanType())
1879 return true;
1880
1881 if (const EnumType *ET = Ty->getAs<EnumType>())
1882 return ET->getDecl()->getIntegerType()->isBooleanType();
1883
1884 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1885 return hasBooleanRepresentation(AT->getValueType());
1886
1887 return false;
1888}
1889
1891 llvm::APInt &Min, llvm::APInt &End,
1892 bool StrictEnums, bool IsBool) {
1893 const EnumType *ET = Ty->getAs<EnumType>();
1894 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1895 ET && !ET->getDecl()->isFixed();
1896 if (!IsBool && !IsRegularCPlusPlusEnum)
1897 return false;
1898
1899 if (IsBool) {
1900 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1901 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1902 } else {
1903 const EnumDecl *ED = ET->getDecl();
1904 ED->getValueRange(End, Min);
1905 }
1906 return true;
1907}
1908
1909llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1910 llvm::APInt Min, End;
1911 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1913 return nullptr;
1914
1915 llvm::MDBuilder MDHelper(getLLVMContext());
1916 return MDHelper.createRange(Min, End);
1917}
1918
1921 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1922 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1923 if (!HasBoolCheck && !HasEnumCheck)
1924 return false;
1925
1926 bool IsBool = hasBooleanRepresentation(Ty) ||
1928 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1929 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1930 if (!NeedsBoolCheck && !NeedsEnumCheck)
1931 return false;
1932
1933 // Single-bit booleans don't need to be checked. Special-case this to avoid
1934 // a bit width mismatch when handling bitfield values. This is handled by
1935 // EmitFromMemory for the non-bitfield case.
1936 if (IsBool &&
1937 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1938 return false;
1939
1940 if (NeedsEnumCheck &&
1941 getContext().isTypeIgnoredBySanitizer(SanitizerKind::Enum, Ty))
1942 return false;
1943
1944 llvm::APInt Min, End;
1945 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1946 return true;
1947
1948 auto &Ctx = getLLVMContext();
1949 SanitizerScope SanScope(this);
1950 llvm::Value *Check;
1951 --End;
1952 if (!Min) {
1953 Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1954 } else {
1955 llvm::Value *Upper =
1956 Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1957 llvm::Value *Lower =
1958 Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1959 Check = Builder.CreateAnd(Upper, Lower);
1960 }
1961 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1964 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1965 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1966 StaticArgs, EmitCheckValue(Value));
1967 return true;
1968}
1969
1970llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1971 QualType Ty,
1973 LValueBaseInfo BaseInfo,
1974 TBAAAccessInfo TBAAInfo,
1975 bool isNontemporal) {
1976 if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr.getBasePointer()))
1977 if (GV->isThreadLocal())
1978 Addr = Addr.withPointer(Builder.CreateThreadLocalAddress(GV),
1980
1981 if (const auto *ClangVecTy = Ty->getAs<VectorType>()) {
1982 // Boolean vectors use `iN` as storage type.
1983 if (ClangVecTy->isExtVectorBoolType()) {
1984 llvm::Type *ValTy = ConvertType(Ty);
1985 unsigned ValNumElems =
1986 cast<llvm::FixedVectorType>(ValTy)->getNumElements();
1987 // Load the `iP` storage object (P is the padded vector size).
1988 auto *RawIntV = Builder.CreateLoad(Addr, Volatile, "load_bits");
1989 const auto *RawIntTy = RawIntV->getType();
1990 assert(RawIntTy->isIntegerTy() && "compressed iN storage for bitvectors");
1991 // Bitcast iP --> <P x i1>.
1992 auto *PaddedVecTy = llvm::FixedVectorType::get(
1993 Builder.getInt1Ty(), RawIntTy->getPrimitiveSizeInBits());
1994 llvm::Value *V = Builder.CreateBitCast(RawIntV, PaddedVecTy);
1995 // Shuffle <P x i1> --> <N x i1> (N is the actual bit size).
1996 V = emitBoolVecConversion(V, ValNumElems, "extractvec");
1997
1998 return EmitFromMemory(V, Ty);
1999 }
2000
2001 // Handle vectors of size 3 like size 4 for better performance.
2002 const llvm::Type *EltTy = Addr.getElementType();
2003 const auto *VTy = cast<llvm::FixedVectorType>(EltTy);
2004
2005 if (!CGM.getCodeGenOpts().PreserveVec3Type && VTy->getNumElements() == 3) {
2006
2007 llvm::VectorType *vec4Ty =
2008 llvm::FixedVectorType::get(VTy->getElementType(), 4);
2009 Address Cast = Addr.withElementType(vec4Ty);
2010 // Now load value.
2011 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
2012
2013 // Shuffle vector to get vec3.
2014 V = Builder.CreateShuffleVector(V, ArrayRef<int>{0, 1, 2}, "extractVec");
2015 return EmitFromMemory(V, Ty);
2016 }
2017 }
2018
2019 // Atomic operations have to be done on integral types.
2020 LValue AtomicLValue =
2021 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
2022 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
2023 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
2024 }
2025
2026 Addr =
2028
2029 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
2030 if (isNontemporal) {
2031 llvm::MDNode *Node = llvm::MDNode::get(
2032 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
2033 Load->setMetadata(llvm::LLVMContext::MD_nontemporal, Node);
2034 }
2035
2036 CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
2037
2038 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
2039 // In order to prevent the optimizer from throwing away the check, don't
2040 // attach range metadata to the load.
2041 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
2042 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty)) {
2043 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
2044 Load->setMetadata(llvm::LLVMContext::MD_noundef,
2045 llvm::MDNode::get(getLLVMContext(), {}));
2046 }
2047
2048 return EmitFromMemory(Load, Ty);
2049}
2050
2051/// Converts a scalar value from its primary IR type (as returned
2052/// by ConvertType) to its load/store type (as returned by
2053/// convertTypeForLoadStore).
2054llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
2055 if (hasBooleanRepresentation(Ty) || Ty->isBitIntType()) {
2056 llvm::Type *StoreTy = convertTypeForLoadStore(Ty, Value->getType());
2058 return Builder.CreateIntCast(Value, StoreTy, Signed, "storedv");
2059 }
2060
2061 if (Ty->isExtVectorBoolType()) {
2062 llvm::Type *StoreTy = convertTypeForLoadStore(Ty, Value->getType());
2063 // Expand to the memory bit width.
2064 unsigned MemNumElems = StoreTy->getPrimitiveSizeInBits();
2065 // <N x i1> --> <P x i1>.
2066 Value = emitBoolVecConversion(Value, MemNumElems, "insertvec");
2067 // <P x i1> --> iP.
2068 Value = Builder.CreateBitCast(Value, StoreTy);
2069 }
2070
2071 return Value;
2072}
2073
2074/// Converts a scalar value from its load/store type (as returned
2075/// by convertTypeForLoadStore) to its primary IR type (as returned
2076/// by ConvertType).
2077llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
2078 if (Ty->isExtVectorBoolType()) {
2079 const auto *RawIntTy = Value->getType();
2080 // Bitcast iP --> <P x i1>.
2081 auto *PaddedVecTy = llvm::FixedVectorType::get(
2082 Builder.getInt1Ty(), RawIntTy->getPrimitiveSizeInBits());
2083 auto *V = Builder.CreateBitCast(Value, PaddedVecTy);
2084 // Shuffle <P x i1> --> <N x i1> (N is the actual bit size).
2085 llvm::Type *ValTy = ConvertType(Ty);
2086 unsigned ValNumElems = cast<llvm::FixedVectorType>(ValTy)->getNumElements();
2087 return emitBoolVecConversion(V, ValNumElems, "extractvec");
2088 }
2089
2090 if (hasBooleanRepresentation(Ty) || Ty->isBitIntType()) {
2091 llvm::Type *ResTy = ConvertType(Ty);
2092 return Builder.CreateTrunc(Value, ResTy, "loadedv");
2093 }
2094
2095 return Value;
2096}
2097
2098// Convert the pointer of \p Addr to a pointer to a vector (the value type of
2099// MatrixType), if it points to a array (the memory type of MatrixType).
2101 CodeGenFunction &CGF,
2102 bool IsVector = true) {
2103 auto *ArrayTy = dyn_cast<llvm::ArrayType>(Addr.getElementType());
2104 if (ArrayTy && IsVector) {
2105 auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
2106 ArrayTy->getNumElements());
2107
2108 return Addr.withElementType(VectorTy);
2109 }
2110 auto *VectorTy = dyn_cast<llvm::VectorType>(Addr.getElementType());
2111 if (VectorTy && !IsVector) {
2112 auto *ArrayTy = llvm::ArrayType::get(
2113 VectorTy->getElementType(),
2114 cast<llvm::FixedVectorType>(VectorTy)->getNumElements());
2115
2116 return Addr.withElementType(ArrayTy);
2117 }
2118
2119 return Addr;
2120}
2121
2122// Emit a store of a matrix LValue. This may require casting the original
2123// pointer to memory address (ArrayType) to a pointer to the value type
2124// (VectorType).
2125static void EmitStoreOfMatrixScalar(llvm::Value *value, LValue lvalue,
2126 bool isInit, CodeGenFunction &CGF) {
2127 Address Addr = MaybeConvertMatrixAddress(lvalue.getAddress(), CGF,
2128 value->getType()->isVectorTy());
2129 CGF.EmitStoreOfScalar(value, Addr, lvalue.isVolatile(), lvalue.getType(),
2130 lvalue.getBaseInfo(), lvalue.getTBAAInfo(), isInit,
2131 lvalue.isNontemporal());
2132}
2133
2134void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
2135 bool Volatile, QualType Ty,
2136 LValueBaseInfo BaseInfo,
2137 TBAAAccessInfo TBAAInfo,
2138 bool isInit, bool isNontemporal) {
2139 if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr.getBasePointer()))
2140 if (GV->isThreadLocal())
2141 Addr = Addr.withPointer(Builder.CreateThreadLocalAddress(GV),
2143
2144 llvm::Type *SrcTy = Value->getType();
2145 if (const auto *ClangVecTy = Ty->getAs<VectorType>()) {
2146 auto *VecTy = dyn_cast<llvm::FixedVectorType>(SrcTy);
2147 if (!CGM.getCodeGenOpts().PreserveVec3Type) {
2148 // Handle vec3 special.
2149 if (VecTy && !ClangVecTy->isExtVectorBoolType() &&
2150 cast<llvm::FixedVectorType>(VecTy)->getNumElements() == 3) {
2151 // Our source is a vec3, do a shuffle vector to make it a vec4.
2152 Value = Builder.CreateShuffleVector(Value, ArrayRef<int>{0, 1, 2, -1},
2153 "extractVec");
2154 SrcTy = llvm::FixedVectorType::get(VecTy->getElementType(), 4);
2155 }
2156 if (Addr.getElementType() != SrcTy) {
2157 Addr = Addr.withElementType(SrcTy);
2158 }
2159 }
2160 }
2161
2162 Value = EmitToMemory(Value, Ty);
2163
2164 LValue AtomicLValue =
2165 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
2166 if (Ty->isAtomicType() ||
2167 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
2168 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
2169 return;
2170 }
2171
2172 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
2173 if (isNontemporal) {
2174 llvm::MDNode *Node =
2175 llvm::MDNode::get(Store->getContext(),
2176 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
2177 Store->setMetadata(llvm::LLVMContext::MD_nontemporal, Node);
2178 }
2179
2180 CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
2181}
2182
2183void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
2184 bool isInit) {
2185 if (lvalue.getType()->isConstantMatrixType()) {
2186 EmitStoreOfMatrixScalar(value, lvalue, isInit, *this);
2187 return;
2188 }
2189
2190 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
2191 lvalue.getType(), lvalue.getBaseInfo(),
2192 lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
2193}
2194
2195// Emit a load of a LValue of matrix type. This may require casting the pointer
2196// to memory address (ArrayType) to a pointer to the value type (VectorType).
2198 CodeGenFunction &CGF) {
2199 assert(LV.getType()->isConstantMatrixType());
2201 LV.setAddress(Addr);
2202 return RValue::get(CGF.EmitLoadOfScalar(LV, Loc));
2203}
2204
2207 QualType Ty = LV.getType();
2208 switch (getEvaluationKind(Ty)) {
2209 case TEK_Scalar:
2210 return EmitLoadOfLValue(LV, Loc);
2211 case TEK_Complex:
2213 case TEK_Aggregate:
2214 EmitAggFinalDestCopy(Ty, Slot, LV, EVK_NonRValue);
2215 return Slot.asRValue();
2216 }
2217 llvm_unreachable("bad evaluation kind");
2218}
2219
2220/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
2221/// method emits the address of the lvalue, then loads the result as an rvalue,
2222/// returning the rvalue.
2224 if (LV.isObjCWeak()) {
2225 // load of a __weak object.
2226 Address AddrWeakObj = LV.getAddress();
2228 AddrWeakObj));
2229 }
2231 // In MRC mode, we do a load+autorelease.
2232 if (!getLangOpts().ObjCAutoRefCount) {
2234 }
2235
2236 // In ARC mode, we load retained and then consume the value.
2237 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
2238 Object = EmitObjCConsumeObject(LV.getType(), Object);
2239 return RValue::get(Object);
2240 }
2241
2242 if (LV.isSimple()) {
2243 assert(!LV.getType()->isFunctionType());
2244
2245 if (LV.getType()->isConstantMatrixType())
2246 return EmitLoadOfMatrixLValue(LV, Loc, *this);
2247
2248 // Everything needs a load.
2249 return RValue::get(EmitLoadOfScalar(LV, Loc));
2250 }
2251
2252 if (LV.isVectorElt()) {
2253 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
2254 LV.isVolatileQualified());
2255 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
2256 "vecext"));
2257 }
2258
2259 // If this is a reference to a subset of the elements of a vector, either
2260 // shuffle the input or extract/insert them as appropriate.
2261 if (LV.isExtVectorElt()) {
2263 }
2264
2265 // Global Register variables always invoke intrinsics
2266 if (LV.isGlobalReg())
2267 return EmitLoadOfGlobalRegLValue(LV);
2268
2269 if (LV.isMatrixElt()) {
2270 llvm::Value *Idx = LV.getMatrixIdx();
2271 if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
2272 const auto *const MatTy = LV.getType()->castAs<ConstantMatrixType>();
2273 llvm::MatrixBuilder MB(Builder);
2274 MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
2275 }
2276 llvm::LoadInst *Load =
2278 return RValue::get(Builder.CreateExtractElement(Load, Idx, "matrixext"));
2279 }
2280
2281 assert(LV.isBitField() && "Unknown LValue type!");
2282 return EmitLoadOfBitfieldLValue(LV, Loc);
2283}
2284
2287 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
2288
2289 // Get the output type.
2290 llvm::Type *ResLTy = ConvertType(LV.getType());
2291
2292 Address Ptr = LV.getBitFieldAddress();
2293 llvm::Value *Val =
2294 Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
2295
2296 bool UseVolatile = LV.isVolatileQualified() &&
2297 Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
2298 const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
2299 const unsigned StorageSize =
2300 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
2301 if (Info.IsSigned) {
2302 assert(static_cast<unsigned>(Offset + Info.Size) <= StorageSize);
2303 unsigned HighBits = StorageSize - Offset - Info.Size;
2304 if (HighBits)
2305 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
2306 if (Offset + HighBits)
2307 Val = Builder.CreateAShr(Val, Offset + HighBits, "bf.ashr");
2308 } else {
2309 if (Offset)
2310 Val = Builder.CreateLShr(Val, Offset, "bf.lshr");
2311 if (static_cast<unsigned>(Offset) + Info.Size < StorageSize)
2312 Val = Builder.CreateAnd(
2313 Val, llvm::APInt::getLowBitsSet(StorageSize, Info.Size), "bf.clear");
2314 }
2315 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
2316 EmitScalarRangeCheck(Val, LV.getType(), Loc);
2317 return RValue::get(Val);
2318}
2319
2320// If this is a reference to a subset of the elements of a vector, create an
2321// appropriate shufflevector.
2323 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
2324 LV.isVolatileQualified());
2325
2326 // HLSL allows treating scalars as one-element vectors. Converting the scalar
2327 // IR value to a vector here allows the rest of codegen to behave as normal.
2328 if (getLangOpts().HLSL && !Vec->getType()->isVectorTy()) {
2329 llvm::Type *DstTy = llvm::FixedVectorType::get(Vec->getType(), 1);
2330 llvm::Value *Zero = llvm::Constant::getNullValue(CGM.Int64Ty);
2331 Vec = Builder.CreateInsertElement(DstTy, Vec, Zero, "cast.splat");
2332 }
2333
2334 const llvm::Constant *Elts = LV.getExtVectorElts();
2335
2336 // If the result of the expression is a non-vector type, we must be extracting
2337 // a single element. Just codegen as an extractelement.
2338 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
2339 if (!ExprVT) {
2340 unsigned InIdx = getAccessedFieldNo(0, Elts);
2341 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2342 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
2343 }
2344
2345 // Always use shuffle vector to try to retain the original program structure
2346 unsigned NumResultElts = ExprVT->getNumElements();
2347
2349 for (unsigned i = 0; i != NumResultElts; ++i)
2350 Mask.push_back(getAccessedFieldNo(i, Elts));
2351
2352 Vec = Builder.CreateShuffleVector(Vec, Mask);
2353 return RValue::get(Vec);
2354}
2355
2356/// Generates lvalue for partial ext_vector access.
2358 Address VectorAddress = LV.getExtVectorAddress();
2359 QualType EQT = LV.getType()->castAs<VectorType>()->getElementType();
2360 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
2361
2362 Address CastToPointerElement = VectorAddress.withElementType(VectorElementTy);
2363
2364 const llvm::Constant *Elts = LV.getExtVectorElts();
2365 unsigned ix = getAccessedFieldNo(0, Elts);
2366
2367 Address VectorBasePtrPlusIx =
2368 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
2369 "vector.elt");
2370
2371 return VectorBasePtrPlusIx;
2372}
2373
2374/// Load of global named registers are always calls to intrinsics.
2376 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
2377 "Bad type for register variable");
2378 llvm::MDNode *RegName = cast<llvm::MDNode>(
2379 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
2380
2381 // We accept integer and pointer types only
2382 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
2383 llvm::Type *Ty = OrigTy;
2384 if (OrigTy->isPointerTy())
2385 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2386 llvm::Type *Types[] = { Ty };
2387
2388 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
2389 llvm::Value *Call = Builder.CreateCall(
2390 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
2391 if (OrigTy->isPointerTy())
2392 Call = Builder.CreateIntToPtr(Call, OrigTy);
2393 return RValue::get(Call);
2394}
2395
2396/// EmitStoreThroughLValue - Store the specified rvalue into the specified
2397/// lvalue, where both are guaranteed to the have the same type, and that type
2398/// is 'Ty'.
2400 bool isInit) {
2401 if (!Dst.isSimple()) {
2402 if (Dst.isVectorElt()) {
2403 // Read/modify/write the vector, inserting the new element.
2404 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
2405 Dst.isVolatileQualified());
2406 auto *IRStoreTy = dyn_cast<llvm::IntegerType>(Vec->getType());
2407 if (IRStoreTy) {
2408 auto *IRVecTy = llvm::FixedVectorType::get(
2409 Builder.getInt1Ty(), IRStoreTy->getPrimitiveSizeInBits());
2410 Vec = Builder.CreateBitCast(Vec, IRVecTy);
2411 // iN --> <N x i1>.
2412 }
2413 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
2414 Dst.getVectorIdx(), "vecins");
2415 if (IRStoreTy) {
2416 // <N x i1> --> <iN>.
2417 Vec = Builder.CreateBitCast(Vec, IRStoreTy);
2418 }
2420 Dst.isVolatileQualified());
2421 return;
2422 }
2423
2424 // If this is an update of extended vector elements, insert them as
2425 // appropriate.
2426 if (Dst.isExtVectorElt())
2428
2429 if (Dst.isGlobalReg())
2430 return EmitStoreThroughGlobalRegLValue(Src, Dst);
2431
2432 if (Dst.isMatrixElt()) {
2433 llvm::Value *Idx = Dst.getMatrixIdx();
2434 if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
2435 const auto *const MatTy = Dst.getType()->castAs<ConstantMatrixType>();
2436 llvm::MatrixBuilder MB(Builder);
2437 MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
2438 }
2439 llvm::Instruction *Load = Builder.CreateLoad(Dst.getMatrixAddress());
2440 llvm::Value *Vec =
2441 Builder.CreateInsertElement(Load, Src.getScalarVal(), Idx, "matins");
2443 Dst.isVolatileQualified());
2444 return;
2445 }
2446
2447 assert(Dst.isBitField() && "Unknown LValue type");
2448 return EmitStoreThroughBitfieldLValue(Src, Dst);
2449 }
2450
2451 // There's special magic for assigning into an ARC-qualified l-value.
2452 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
2453 switch (Lifetime) {
2455 llvm_unreachable("present but none");
2456
2458 // nothing special
2459 break;
2460
2462 if (isInit) {
2463 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
2464 break;
2465 }
2466 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
2467 return;
2468
2470 if (isInit)
2471 // Initialize and then skip the primitive store.
2473 else
2475 /*ignore*/ true);
2476 return;
2477
2480 Src.getScalarVal()));
2481 // fall into the normal path
2482 break;
2483 }
2484 }
2485
2486 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
2487 // load of a __weak object.
2488 Address LvalueDst = Dst.getAddress();
2489 llvm::Value *src = Src.getScalarVal();
2490 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
2491 return;
2492 }
2493
2494 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
2495 // load of a __strong object.
2496 Address LvalueDst = Dst.getAddress();
2497 llvm::Value *src = Src.getScalarVal();
2498 if (Dst.isObjCIvar()) {
2499 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2500 llvm::Type *ResultType = IntPtrTy;
2502 llvm::Value *RHS = dst.emitRawPointer(*this);
2503 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2504 llvm::Value *LHS = Builder.CreatePtrToInt(LvalueDst.emitRawPointer(*this),
2505 ResultType, "sub.ptr.lhs.cast");
2506 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2507 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst, BytesBetween);
2508 } else if (Dst.isGlobalObjCRef()) {
2509 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2510 Dst.isThreadLocalRef());
2511 }
2512 else
2513 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2514 return;
2515 }
2516
2517 assert(Src.isScalar() && "Can't emit an agg store with this method");
2518 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2519}
2520
2522 llvm::Value **Result) {
2523 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2524 llvm::Type *ResLTy = convertTypeForLoadStore(Dst.getType());
2525 Address Ptr = Dst.getBitFieldAddress();
2526
2527 // Get the source value, truncated to the width of the bit-field.
2528 llvm::Value *SrcVal = Src.getScalarVal();
2529
2530 // Cast the source to the storage type and shift it into place.
2531 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2532 /*isSigned=*/false);
2533 llvm::Value *MaskedVal = SrcVal;
2534
2535 const bool UseVolatile =
2536 CGM.getCodeGenOpts().AAPCSBitfieldWidth && Dst.isVolatileQualified() &&
2537 Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
2538 const unsigned StorageSize =
2539 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
2540 const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
2541 // See if there are other bits in the bitfield's storage we'll need to load
2542 // and mask together with source before storing.
2543 if (StorageSize != Info.Size) {
2544 assert(StorageSize > Info.Size && "Invalid bitfield size.");
2545 llvm::Value *Val =
2546 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2547
2548 // Mask the source value as needed.
2550 SrcVal = Builder.CreateAnd(
2551 SrcVal, llvm::APInt::getLowBitsSet(StorageSize, Info.Size),
2552 "bf.value");
2553 MaskedVal = SrcVal;
2554 if (Offset)
2555 SrcVal = Builder.CreateShl(SrcVal, Offset, "bf.shl");
2556
2557 // Mask out the original value.
2558 Val = Builder.CreateAnd(
2559 Val, ~llvm::APInt::getBitsSet(StorageSize, Offset, Offset + Info.Size),
2560 "bf.clear");
2561
2562 // Or together the unchanged values and the source value.
2563 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2564 } else {
2565 assert(Offset == 0);
2566 // According to the AACPS:
2567 // When a volatile bit-field is written, and its container does not overlap
2568 // with any non-bit-field member, its container must be read exactly once
2569 // and written exactly once using the access width appropriate to the type
2570 // of the container. The two accesses are not atomic.
2571 if (Dst.isVolatileQualified() && isAAPCS(CGM.getTarget()) &&
2572 CGM.getCodeGenOpts().ForceAAPCSBitfieldLoad)
2573 Builder.CreateLoad(Ptr, true, "bf.load");
2574 }
2575
2576 // Write the new value back out.
2577 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2578
2579 // Return the new value of the bit-field, if requested.
2580 if (Result) {
2581 llvm::Value *ResultVal = MaskedVal;
2582
2583 // Sign extend the value if needed.
2584 if (Info.IsSigned) {
2585 assert(Info.Size <= StorageSize);
2586 unsigned HighBits = StorageSize - Info.Size;
2587 if (HighBits) {
2588 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2589 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2590 }
2591 }
2592
2593 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2594 "bf.result.cast");
2595 *Result = EmitFromMemory(ResultVal, Dst.getType());
2596 }
2597}
2598
2600 LValue Dst) {
2601 // HLSL allows storing to scalar values through ExtVector component LValues.
2602 // To support this we need to handle the case where the destination address is
2603 // a scalar.
2604 Address DstAddr = Dst.getExtVectorAddress();
2605 if (!DstAddr.getElementType()->isVectorTy()) {
2606 assert(!Dst.getType()->isVectorType() &&
2607 "this should only occur for non-vector l-values");
2608 Builder.CreateStore(Src.getScalarVal(), DstAddr, Dst.isVolatileQualified());
2609 return;
2610 }
2611
2612 // This access turns into a read/modify/write of the vector. Load the input
2613 // value now.
2614 llvm::Value *Vec = Builder.CreateLoad(DstAddr, Dst.isVolatileQualified());
2615 const llvm::Constant *Elts = Dst.getExtVectorElts();
2616
2617 llvm::Value *SrcVal = Src.getScalarVal();
2618
2619 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2620 unsigned NumSrcElts = VTy->getNumElements();
2621 unsigned NumDstElts =
2622 cast<llvm::FixedVectorType>(Vec->getType())->getNumElements();
2623 if (NumDstElts == NumSrcElts) {
2624 // Use shuffle vector is the src and destination are the same number of
2625 // elements and restore the vector mask since it is on the side it will be
2626 // stored.
2627 SmallVector<int, 4> Mask(NumDstElts);
2628 for (unsigned i = 0; i != NumSrcElts; ++i)
2629 Mask[getAccessedFieldNo(i, Elts)] = i;
2630
2631 Vec = Builder.CreateShuffleVector(SrcVal, Mask);
2632 } else if (NumDstElts > NumSrcElts) {
2633 // Extended the source vector to the same length and then shuffle it
2634 // into the destination.
2635 // FIXME: since we're shuffling with undef, can we just use the indices
2636 // into that? This could be simpler.
2637 SmallVector<int, 4> ExtMask;
2638 for (unsigned i = 0; i != NumSrcElts; ++i)
2639 ExtMask.push_back(i);
2640 ExtMask.resize(NumDstElts, -1);
2641 llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal, ExtMask);
2642 // build identity
2644 for (unsigned i = 0; i != NumDstElts; ++i)
2645 Mask.push_back(i);
2646
2647 // When the vector size is odd and .odd or .hi is used, the last element
2648 // of the Elts constant array will be one past the size of the vector.
2649 // Ignore the last element here, if it is greater than the mask size.
2650 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2651 NumSrcElts--;
2652
2653 // modify when what gets shuffled in
2654 for (unsigned i = 0; i != NumSrcElts; ++i)
2655 Mask[getAccessedFieldNo(i, Elts)] = i + NumDstElts;
2656 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, Mask);
2657 } else {
2658 // We should never shorten the vector
2659 llvm_unreachable("unexpected shorten vector length");
2660 }
2661 } else {
2662 // If the Src is a scalar (not a vector), and the target is a vector it must
2663 // be updating one element.
2664 unsigned InIdx = getAccessedFieldNo(0, Elts);
2665 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2666 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2667 }
2668
2670 Dst.isVolatileQualified());
2671}
2672
2673/// Store of global named registers are always calls to intrinsics.
2675 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2676 "Bad type for register variable");
2677 llvm::MDNode *RegName = cast<llvm::MDNode>(
2678 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2679 assert(RegName && "Register LValue is not metadata");
2680
2681 // We accept integer and pointer types only
2682 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2683 llvm::Type *Ty = OrigTy;
2684 if (OrigTy->isPointerTy())
2685 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2686 llvm::Type *Types[] = { Ty };
2687
2688 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2689 llvm::Value *Value = Src.getScalarVal();
2690 if (OrigTy->isPointerTy())
2691 Value = Builder.CreatePtrToInt(Value, Ty);
2692 Builder.CreateCall(
2693 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2694}
2695
2696// setObjCGCLValueClass - sets class of the lvalue for the purpose of
2697// generating write-barries API. It is currently a global, ivar,
2698// or neither.
2699static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2700 LValue &LV,
2701 bool IsMemberAccess=false) {
2702 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2703 return;
2704
2705 if (isa<ObjCIvarRefExpr>(E)) {
2706 QualType ExpTy = E->getType();
2707 if (IsMemberAccess && ExpTy->isPointerType()) {
2708 // If ivar is a structure pointer, assigning to field of
2709 // this struct follows gcc's behavior and makes it a non-ivar
2710 // writer-barrier conservatively.
2711 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2712 if (ExpTy->isRecordType()) {
2713 LV.setObjCIvar(false);
2714 return;
2715 }
2716 }
2717 LV.setObjCIvar(true);
2718 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2719 LV.setBaseIvarExp(Exp->getBase());
2721 return;
2722 }
2723
2724 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2725 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2726 if (VD->hasGlobalStorage()) {
2727 LV.setGlobalObjCRef(true);
2728 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2729 }
2730 }
2732 return;
2733 }
2734
2735 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2736 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2737 return;
2738 }
2739
2740 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2741 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2742 if (LV.isObjCIvar()) {
2743 // If cast is to a structure pointer, follow gcc's behavior and make it
2744 // a non-ivar write-barrier.
2745 QualType ExpTy = E->getType();
2746 if (ExpTy->isPointerType())
2747 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2748 if (ExpTy->isRecordType())
2749 LV.setObjCIvar(false);
2750 }
2751 return;
2752 }
2753
2754 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2755 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2756 return;
2757 }
2758
2759 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2760 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2761 return;
2762 }
2763
2764 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2765 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2766 return;
2767 }
2768
2769 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2770 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2771 return;
2772 }
2773
2774 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2775 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2776 if (LV.isObjCIvar() && !LV.isObjCArray())
2777 // Using array syntax to assigning to what an ivar points to is not
2778 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2779 LV.setObjCIvar(false);
2780 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2781 // Using array syntax to assigning to what global points to is not
2782 // same as assigning to the global itself. {id *G;} G[i] = 0;
2783 LV.setGlobalObjCRef(false);
2784 return;
2785 }
2786
2787 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2788 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2789 // We don't know if member is an 'ivar', but this flag is looked at
2790 // only in the context of LV.isObjCIvar().
2792 return;
2793 }
2794}
2795
2797 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2798 llvm::Type *RealVarTy, SourceLocation Loc) {
2799 if (CGF.CGM.getLangOpts().OpenMPIRBuilder)
2801 CGF, VD, Addr, Loc);
2802 else
2803 Addr =
2804 CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2805
2806 Addr = Addr.withElementType(RealVarTy);
2807 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2808}
2809
2811 const VarDecl *VD, QualType T) {
2812 std::optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2813 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2814 // Return an invalid address if variable is MT_To (or MT_Enter starting with
2815 // OpenMP 5.2) and unified memory is not enabled. For all other cases: MT_Link
2816 // and MT_To (or MT_Enter) with unified memory, return a valid address.
2817 if (!Res || ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
2818 *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
2820 return Address::invalid();
2821 assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2822 ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
2823 *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
2825 "Expected link clause OR to clause with unified memory enabled.");
2826 QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2828 return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2829}
2830
2831Address
2833 LValueBaseInfo *PointeeBaseInfo,
2834 TBAAAccessInfo *PointeeTBAAInfo) {
2835 llvm::LoadInst *Load =
2836 Builder.CreateLoad(RefLVal.getAddress(), RefLVal.isVolatile());
2838 return makeNaturalAddressForPointer(Load, RefLVal.getType()->getPointeeType(),
2839 CharUnits(), /*ForPointeeType=*/true,
2840 PointeeBaseInfo, PointeeTBAAInfo);
2841}
2842
2844 LValueBaseInfo PointeeBaseInfo;
2845 TBAAAccessInfo PointeeTBAAInfo;
2846 Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2847 &PointeeTBAAInfo);
2848 return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2849 PointeeBaseInfo, PointeeTBAAInfo);
2850}
2851
2853 const PointerType *PtrTy,
2854 LValueBaseInfo *BaseInfo,
2855 TBAAAccessInfo *TBAAInfo) {
2856 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2857 return makeNaturalAddressForPointer(Addr, PtrTy->getPointeeType(),
2858 CharUnits(), /*ForPointeeType=*/true,
2859 BaseInfo, TBAAInfo);
2860}
2861
2863 const PointerType *PtrTy) {
2864 LValueBaseInfo BaseInfo;
2865 TBAAAccessInfo TBAAInfo;
2866 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2867 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2868}
2869
2871 const Expr *E, const VarDecl *VD) {
2872 QualType T = E->getType();
2873
2874 // If it's thread_local, emit a call to its wrapper function instead.
2875 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2877 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2878 // Check if the variable is marked as declare target with link clause in
2879 // device codegen.
2880 if (CGF.getLangOpts().OpenMPIsTargetDevice) {
2881 Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2882 if (Addr.isValid())
2883 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2884 }
2885
2886 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2887
2888 if (VD->getTLSKind() != VarDecl::TLS_None)
2889 V = CGF.Builder.CreateThreadLocalAddress(V);
2890
2891 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2892 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2893 Address Addr(V, RealVarTy, Alignment);
2894 // Emit reference to the private copy of the variable if it is an OpenMP
2895 // threadprivate variable.
2896 if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2897 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2898 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2899 E->getExprLoc());
2900 }
2901 LValue LV = VD->getType()->isReferenceType() ?
2902 CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2905 setObjCGCLValueClass(CGF.getContext(), E, LV);
2906 return LV;
2907}
2908
2910 llvm::Type *Ty) {
2911 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2912 if (FD->hasAttr<WeakRefAttr>()) {
2914 return aliasee.getPointer();
2915 }
2916
2917 llvm::Constant *V = GetAddrOfFunction(GD, Ty);
2918 return V;
2919}
2920
2922 GlobalDecl GD) {
2923 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2924 llvm::Constant *V = CGF.CGM.getFunctionPointer(GD);
2925 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2926 return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2928}
2929
2931 llvm::Value *ThisValue) {
2932
2933 return CGF.EmitLValueForLambdaField(FD, ThisValue);
2934}
2935
2936/// Named Registers are named metadata pointing to the register name
2937/// which will be read from/written to as an argument to the intrinsic
2938/// @llvm.read/write_register.
2939/// So far, only the name is being passed down, but other options such as
2940/// register type, allocation type or even optimization options could be
2941/// passed down via the metadata node.
2943 SmallString<64> Name("llvm.named.register.");
2944 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2945 assert(Asm->getLabel().size() < 64-Name.size() &&
2946 "Register name too big");
2947 Name.append(Asm->getLabel());
2948 llvm::NamedMDNode *M =
2949 CGM.getModule().getOrInsertNamedMetadata(Name);
2950 if (M->getNumOperands() == 0) {
2951 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2952 Asm->getLabel());
2953 llvm::Metadata *Ops[] = {Str};
2954 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2955 }
2956
2957 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2958
2959 llvm::Value *Ptr =
2960 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2961 return LValue::MakeGlobalReg(Ptr, Alignment, VD->getType());
2962}
2963
2964/// Determine whether we can emit a reference to \p VD from the current
2965/// context, despite not necessarily having seen an odr-use of the variable in
2966/// this context.
2968 const DeclRefExpr *E,
2969 const VarDecl *VD) {
2970 // For a variable declared in an enclosing scope, do not emit a spurious
2971 // reference even if we have a capture, as that will emit an unwarranted
2972 // reference to our capture state, and will likely generate worse code than
2973 // emitting a local copy.
2974 if (E->refersToEnclosingVariableOrCapture())
2975 return false;
2976
2977 // For a local declaration declared in this function, we can always reference
2978 // it even if we don't have an odr-use.
2979 if (VD->hasLocalStorage()) {
2980 return VD->getDeclContext() ==
2981 dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2982 }
2983
2984 // For a global declaration, we can emit a reference to it if we know
2985 // for sure that we are able to emit a definition of it.
2986 VD = VD->getDefinition(CGF.getContext());
2987 if (!VD)
2988 return false;
2989
2990 // Don't emit a spurious reference if it might be to a variable that only
2991 // exists on a different device / target.
2992 // FIXME: This is unnecessarily broad. Check whether this would actually be a
2993 // cross-target reference.
2994 if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2995 CGF.getLangOpts().OpenCL) {
2996 return false;
2997 }
2998
2999 // We can emit a spurious reference only if the linkage implies that we'll
3000 // be emitting a non-interposable symbol that will be retained until link
3001 // time.
3002 switch (CGF.CGM.getLLVMLinkageVarDefinition(VD)) {
3003 case llvm::GlobalValue::ExternalLinkage:
3004 case llvm::GlobalValue::LinkOnceODRLinkage:
3005 case llvm::GlobalValue::WeakODRLinkage:
3006 case llvm::GlobalValue::InternalLinkage:
3007 case llvm::GlobalValue::PrivateLinkage:
3008 return true;
3009 default:
3010 return false;
3011 }
3012}
3013
3015 const NamedDecl *ND = E->getDecl();
3016 QualType T = E->getType();
3017
3018 assert(E->isNonOdrUse() != NOUR_Unevaluated &&
3019 "should not emit an unevaluated operand");
3020
3021 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
3022 // Global Named registers access via intrinsics only
3023 if (VD->getStorageClass() == SC_Register &&
3024 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
3025 return EmitGlobalNamedRegister(VD, CGM);
3026
3027 // If this DeclRefExpr does not constitute an odr-use of the variable,
3028 // we're not permitted to emit a reference to it in general, and it might
3029 // not be captured if capture would be necessary for a use. Emit the
3030 // constant value directly instead.
3031 if (E->isNonOdrUse() == NOUR_Constant &&
3032 (VD->getType()->isReferenceType() ||
3033 !canEmitSpuriousReferenceToVariable(*this, E, VD))) {
3034 VD->getAnyInitializer(VD);
3035 llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
3036 E->getLocation(), *VD->evaluateValue(), VD->getType());
3037 assert(Val && "failed to emit constant expression");
3038
3039 Address Addr = Address::invalid();
3040 if (!VD->getType()->isReferenceType()) {
3041 // Spill the constant value to a global.
3042 Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
3043 getContext().getDeclAlign(VD));
3044 llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
3045 auto *PTy = llvm::PointerType::get(
3046 VarTy, getTypes().getTargetAddressSpace(VD->getType()));
3047 Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy, VarTy);
3048 } else {
3049 // Should we be using the alignment of the constant pointer we emitted?
3050 CharUnits Alignment =
3052 /* BaseInfo= */ nullptr,
3053 /* TBAAInfo= */ nullptr,
3054 /* forPointeeType= */ true);
3055 Addr = makeNaturalAddressForPointer(Val, T, Alignment);
3056 }
3057 return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
3058 }
3059
3060 // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
3061
3062 // Check for captured variables.
3063 if (E->refersToEnclosingVariableOrCapture()) {
3064 VD = VD->getCanonicalDecl();
3065 if (auto *FD = LambdaCaptureFields.lookup(VD))
3066 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
3067 if (CapturedStmtInfo) {
3068 auto I = LocalDeclMap.find(VD);
3069 if (I != LocalDeclMap.end()) {
3070 LValue CapLVal;
3071 if (VD->getType()->isReferenceType())
3072 CapLVal = EmitLoadOfReferenceLValue(I->second, VD->getType(),
3074 else
3075 CapLVal = MakeAddrLValue(I->second, T);
3076 // Mark lvalue as nontemporal if the variable is marked as nontemporal
3077 // in simd context.
3078 if (getLangOpts().OpenMP &&
3080 CapLVal.setNontemporal(/*Value=*/true);
3081 return CapLVal;
3082 }
3083 LValue CapLVal =
3086 Address LValueAddress = CapLVal.getAddress();
3087 CapLVal = MakeAddrLValue(Address(LValueAddress.emitRawPointer(*this),
3088 LValueAddress.getElementType(),
3089 getContext().getDeclAlign(VD)),
3090 CapLVal.getType(),
3092 CapLVal.getTBAAInfo());
3093 // Mark lvalue as nontemporal if the variable is marked as nontemporal
3094 // in simd context.
3095 if (getLangOpts().OpenMP &&
3097 CapLVal.setNontemporal(/*Value=*/true);
3098 return CapLVal;
3099 }
3100
3101 assert(isa<BlockDecl>(CurCodeDecl));
3102 Address addr = GetAddrOfBlockDecl(VD);
3103 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
3104 }
3105 }
3106
3107 // FIXME: We should be able to assert this for FunctionDecls as well!
3108 // FIXME: We should be able to assert this for all DeclRefExprs, not just
3109 // those with a valid source location.
3110 assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
3111 !E->getLocation().isValid()) &&
3112 "Should not use decl without marking it used!");
3113
3114 if (ND->hasAttr<WeakRefAttr>()) {
3115 const auto *VD = cast<ValueDecl>(ND);
3117 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
3118 }
3119
3120 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
3121 // Check if this is a global variable.
3122 if (VD->hasLinkage() || VD->isStaticDataMember())
3123 return EmitGlobalVarDeclLValue(*this, E, VD);
3124
3125 Address addr = Address::invalid();
3126
3127 // The variable should generally be present in the local decl map.
3128 auto iter = LocalDeclMap.find(VD);
3129 if (iter != LocalDeclMap.end()) {
3130 addr = iter->second;
3131
3132 // Otherwise, it might be static local we haven't emitted yet for
3133 // some reason; most likely, because it's in an outer function.
3134 } else if (VD->isStaticLocal()) {
3135 llvm::Constant *var = CGM.getOrCreateStaticVarDecl(
3137 addr = Address(
3138 var, ConvertTypeForMem(VD->getType()), getContext().getDeclAlign(VD));
3139
3140 // No other cases for now.
3141 } else {
3142 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
3143 }
3144
3145 // Handle threadlocal function locals.
3146 if (VD->getTLSKind() != VarDecl::TLS_None)
3147 addr = addr.withPointer(
3148 Builder.CreateThreadLocalAddress(addr.getBasePointer()),
3150
3151 // Check for OpenMP threadprivate variables.
3152 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
3153 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
3155 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
3156 E->getExprLoc());
3157 }
3158
3159 // Drill into block byref variables.
3160 bool isBlockByref = VD->isEscapingByref();
3161 if (isBlockByref) {
3162 addr = emitBlockByrefAddress(addr, VD);
3163 }
3164
3165 // Drill into reference types.
3166 LValue LV = VD->getType()->isReferenceType() ?
3167 EmitLoadOfReferenceLValue(addr, VD->getType(), AlignmentSource::Decl) :
3169
3170 bool isLocalStorage = VD->hasLocalStorage();
3171
3172 bool NonGCable = isLocalStorage &&
3173 !VD->getType()->isReferenceType() &&
3174 !isBlockByref;
3175 if (NonGCable) {
3177 LV.setNonGC(true);
3178 }
3179
3180 bool isImpreciseLifetime =
3181 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
3182 if (isImpreciseLifetime)
3185 return LV;
3186 }
3187
3188 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3189 return EmitFunctionDeclLValue(*this, E, FD);
3190
3191 // FIXME: While we're emitting a binding from an enclosing scope, all other
3192 // DeclRefExprs we see should be implicitly treated as if they also refer to
3193 // an enclosing scope.
3194 if (const auto *BD = dyn_cast<BindingDecl>(ND)) {
3195 if (E->refersToEnclosingVariableOrCapture()) {
3196 auto *FD = LambdaCaptureFields.lookup(BD);
3197 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
3198 }
3199 return EmitLValue(BD->getBinding());
3200 }
3201
3202 // We can form DeclRefExprs naming GUID declarations when reconstituting
3203 // non-type template parameters into expressions.
3204 if (const auto *GD = dyn_cast<MSGuidDecl>(ND))
3207
3208 if (const auto *TPO = dyn_cast<TemplateParamObjectDecl>(ND)) {
3209 auto ATPO = CGM.GetAddrOfTemplateParamObject(TPO);
3210 auto AS = getLangASFromTargetAS(ATPO.getAddressSpace());
3211
3212 if (AS != T.getAddressSpace()) {
3213 auto TargetAS = getContext().getTargetAddressSpace(T.getAddressSpace());
3214 auto PtrTy = llvm::PointerType::get(CGM.getLLVMContext(), TargetAS);
3216 CGM, ATPO.getPointer(), AS, T.getAddressSpace(), PtrTy);
3217 ATPO = ConstantAddress(ASC, ATPO.getElementType(), ATPO.getAlignment());
3218 }
3219
3220 return MakeAddrLValue(ATPO, T, AlignmentSource::Decl);
3221 }
3222
3223 llvm_unreachable("Unhandled DeclRefExpr");
3224}
3225
3227 // __extension__ doesn't affect lvalue-ness.
3228 if (E->getOpcode() == UO_Extension)
3229 return EmitLValue(E->getSubExpr());
3230
3231 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
3232 switch (E->getOpcode()) {
3233 default: llvm_unreachable("Unknown unary operator lvalue!");
3234 case UO_Deref: {
3235 QualType T = E->getSubExpr()->getType()->getPointeeType();
3236 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
3237
3238 LValueBaseInfo BaseInfo;
3239 TBAAAccessInfo TBAAInfo;
3240 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
3241 &TBAAInfo);
3242 LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
3244
3245 // We should not generate __weak write barrier on indirect reference
3246 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
3247 // But, we continue to generate __strong write barrier on indirect write
3248 // into a pointer to object.
3249 if (getLangOpts().ObjC &&
3250 getLangOpts().getGC() != LangOptions::NonGC &&
3251 LV.isObjCWeak())
3253 return LV;
3254 }
3255 case UO_Real:
3256 case UO_Imag: {
3257 LValue LV = EmitLValue(E->getSubExpr());
3258 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
3259
3260 // __real is valid on scalars. This is a faster way of testing that.
3261 // __imag can only produce an rvalue on scalars.
3262 if (E->getOpcode() == UO_Real &&
3263 !LV.getAddress().getElementType()->isStructTy()) {
3264 assert(E->getSubExpr()->getType()->isArithmeticType());
3265 return LV;
3266 }
3267
3268 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
3269
3270 Address Component =
3271 (E->getOpcode() == UO_Real
3273 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
3274 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
3276 ElemLV.getQuals().addQualifiers(LV.getQuals());
3277 return ElemLV;
3278 }
3279 case UO_PreInc:
3280 case UO_PreDec: {
3281 LValue LV = EmitLValue(E->getSubExpr());
3282 bool isInc = E->getOpcode() == UO_PreInc;
3283
3284 if (E->getType()->isAnyComplexType())
3285 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
3286 else
3287 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
3288 return LV;
3289 }
3290 }
3291}
3292
3296}
3297
3301}
3302
3304 auto SL = E->getFunctionName();
3305 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
3306 StringRef FnName = CurFn->getName();
3307 if (FnName.starts_with("\01"))
3308 FnName = FnName.substr(1);
3309 StringRef NameItems[] = {
3310 PredefinedExpr::getIdentKindName(E->getIdentKind()), FnName};
3311 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
3312 if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
3313 std::string Name = std::string(SL->getString());
3314 if (!Name.empty()) {
3315 unsigned Discriminator =
3317 if (Discriminator)
3318 Name += "_" + Twine(Discriminator + 1).str();
3319 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
3321 } else {
3322 auto C =
3323 CGM.GetAddrOfConstantCString(std::string(FnName), GVName.c_str());
3325 }
3326 }
3327 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
3329}
3330
3331/// Emit a type description suitable for use by a runtime sanitizer library. The
3332/// format of a type descriptor is
3333///
3334/// \code
3335/// { i16 TypeKind, i16 TypeInfo }
3336/// \endcode
3337///
3338/// followed by an array of i8 containing the type name with extra information
3339/// for BitInt. TypeKind is TK_Integer(0) for an integer, TK_Float(1) for a
3340/// floating point value, TK_BitInt(2) for BitInt and TK_Unknown(0xFFFF) for
3341/// anything else.
3343 // Only emit each type's descriptor once.
3344 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
3345 return C;
3346
3347 uint16_t TypeKind = TK_Unknown;
3348 uint16_t TypeInfo = 0;
3349 bool IsBitInt = false;
3350
3351 if (T->isIntegerType()) {
3352 TypeKind = TK_Integer;
3353 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
3354 (T->isSignedIntegerType() ? 1 : 0);
3355 // Follow suggestion from discussion of issue 64100.
3356 // So we can write the exact amount of bits in TypeName after '\0'
3357 // making it <diagnostic-like type name>.'\0'.<32-bit width>.
3358 if (T->isSignedIntegerType() && T->getAs<BitIntType>()) {
3359 // Do a sanity checks as we are using 32-bit type to store bit length.
3360 assert(getContext().getTypeSize(T) > 0 &&
3361 " non positive amount of bits in __BitInt type");
3362 assert(getContext().getTypeSize(T) <= 0xFFFFFFFF &&
3363 " too many bits in __BitInt type");
3364
3365 // Redefine TypeKind with the actual __BitInt type if we have signed
3366 // BitInt.
3367 TypeKind = TK_BitInt;
3368 IsBitInt = true;
3369 }
3370 } else if (T->isFloatingType()) {
3371 TypeKind = TK_Float;
3373 }
3374
3375 // Format the type name as if for a diagnostic, including quotes and
3376 // optionally an 'aka'.
3377 SmallString<32> Buffer;
3379 (intptr_t)T.getAsOpaquePtr(), StringRef(),
3380 StringRef(), {}, Buffer, {});
3381
3382 if (IsBitInt) {
3383 // The Structure is: 0 to end the string, 32 bit unsigned integer in target
3384 // endianness, zero.
3385 char S[6] = {'\0', '\0', '\0', '\0', '\0', '\0'};
3386 const auto *EIT = T->castAs<BitIntType>();
3387 uint32_t Bits = EIT->getNumBits();
3388 llvm::support::endian::write32(S + 1, Bits,
3389 getTarget().isBigEndian()
3390 ? llvm::endianness::big
3391 : llvm::endianness::little);
3392 StringRef Str = StringRef(S, sizeof(S) / sizeof(decltype(S[0])));
3393 Buffer.append(Str);
3394 }
3395
3396 llvm::Constant *Components[] = {
3397 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
3398 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
3399 };
3400 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
3401
3402 auto *GV = new llvm::GlobalVariable(
3403 CGM.getModule(), Descriptor->getType(),
3404 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
3405 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3407
3408 // Remember the descriptor for this type.
3410
3411 return GV;
3412}
3413
3414llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
3415 llvm::Type *TargetTy = IntPtrTy;
3416
3417 if (V->getType() == TargetTy)
3418 return V;
3419
3420 // Floating-point types which fit into intptr_t are bitcast to integers
3421 // and then passed directly (after zero-extension, if necessary).
3422 if (V->getType()->isFloatingPointTy()) {
3423 unsigned Bits = V->getType()->getPrimitiveSizeInBits().getFixedValue();
3424 if (Bits <= TargetTy->getIntegerBitWidth())
3425 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
3426 Bits));
3427 }
3428
3429 // Integers which fit in intptr_t are zero-extended and passed directly.
3430 if (V->getType()->isIntegerTy() &&
3431 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
3432 return Builder.CreateZExt(V, TargetTy);
3433
3434 // Pointers are passed directly, everything else is passed by address.
3435 if (!V->getType()->isPointerTy()) {
3436 RawAddress Ptr = CreateDefaultAlignTempAlloca(V->getType());
3437 Builder.CreateStore(V, Ptr);
3438 V = Ptr.getPointer();
3439 }
3440 return Builder.CreatePtrToInt(V, TargetTy);
3441}
3442
3443/// Emit a representation of a SourceLocation for passing to a handler
3444/// in a sanitizer runtime library. The format for this data is:
3445/// \code
3446/// struct SourceLocation {
3447/// const char *Filename;
3448/// int32_t Line, Column;
3449/// };
3450/// \endcode
3451/// For an invalid SourceLocation, the Filename pointer is null.
3453 llvm::Constant *Filename;
3454 int Line, Column;
3455
3457 if (PLoc.isValid()) {
3458 StringRef FilenameString = PLoc.getFilename();
3459
3460 int PathComponentsToStrip =
3461 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
3462 if (PathComponentsToStrip < 0) {
3463 assert(PathComponentsToStrip != INT_MIN);
3464 int PathComponentsToKeep = -PathComponentsToStrip;
3465 auto I = llvm::sys::path::rbegin(FilenameString);
3466 auto E = llvm::sys::path::rend(FilenameString);
3467 while (I != E && --PathComponentsToKeep)
3468 ++I;
3469
3470 FilenameString = FilenameString.substr(I - E);
3471 } else if (PathComponentsToStrip > 0) {
3472 auto I = llvm::sys::path::begin(FilenameString);
3473 auto E = llvm::sys::path::end(FilenameString);
3474 while (I != E && PathComponentsToStrip--)
3475 ++I;
3476
3477 if (I != E)
3478 FilenameString =
3479 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
3480 else
3481 FilenameString = llvm::sys::path::filename(FilenameString);
3482 }
3483
3484 auto FilenameGV =
3485 CGM.GetAddrOfConstantCString(std::string(FilenameString), ".src");
3487 cast<llvm::GlobalVariable>(
3488 FilenameGV.getPointer()->stripPointerCasts()));
3489 Filename = FilenameGV.getPointer();
3490 Line = PLoc.getLine();
3491 Column = PLoc.getColumn();
3492 } else {
3493 Filename = llvm::Constant::getNullValue(Int8PtrTy);
3494 Line = Column = 0;
3495 }
3496
3497 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
3498 Builder.getInt32(Column)};
3499
3500 return llvm::ConstantStruct::getAnon(Data);
3501}
3502
3503namespace {
3504/// Specify under what conditions this check can be recovered
3505enum class CheckRecoverableKind {
3506 /// Always terminate program execution if this check fails.
3508 /// Check supports recovering, runtime has both fatal (noreturn) and
3509 /// non-fatal handlers for this check.
3510 Recoverable,
3511 /// Runtime conditionally aborts, always need to support recovery.
3513};
3514}
3515
3516static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
3517 assert(Kind.countPopulation() == 1);
3518 if (Kind == SanitizerKind::Vptr)
3519 return CheckRecoverableKind::AlwaysRecoverable;
3520 else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
3521 return CheckRecoverableKind::Unrecoverable;
3522 else
3523 return CheckRecoverableKind::Recoverable;
3524}
3525
3526namespace {
3527struct SanitizerHandlerInfo {
3528 char const *const Name;
3529 unsigned Version;
3530};
3531}
3532
3533const SanitizerHandlerInfo SanitizerHandlers[] = {
3534#define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
3536#undef SANITIZER_CHECK
3537};
3538
3540 llvm::FunctionType *FnType,
3542 SanitizerHandler CheckHandler,
3543 CheckRecoverableKind RecoverKind, bool IsFatal,
3544 llvm::BasicBlock *ContBB, bool NoMerge) {
3545 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
3546 std::optional<ApplyDebugLocation> DL;
3547 if (!CGF.Builder.getCurrentDebugLocation()) {
3548 // Ensure that the call has at least an artificial debug location.
3549 DL.emplace(CGF, SourceLocation());
3550 }
3551 bool NeedsAbortSuffix =
3552 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
3553 bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
3554 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
3555 const StringRef CheckName = CheckInfo.Name;
3556 std::string FnName = "__ubsan_handle_" + CheckName.str();
3557 if (CheckInfo.Version && !MinimalRuntime)
3558 FnName += "_v" + llvm::utostr(CheckInfo.Version);
3559 if (MinimalRuntime)
3560 FnName += "_minimal";
3561 if (NeedsAbortSuffix)
3562 FnName += "_abort";
3563 bool MayReturn =
3564 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
3565
3566 llvm::AttrBuilder B(CGF.getLLVMContext());
3567 if (!MayReturn) {
3568 B.addAttribute(llvm::Attribute::NoReturn)
3569 .addAttribute(llvm::Attribute::NoUnwind);
3570 }
3571 B.addUWTableAttr(llvm::UWTableKind::Default);
3572
3573 llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
3574 FnType, FnName,
3575 llvm::AttributeList::get(CGF.getLLVMContext(),
3576 llvm::AttributeList::FunctionIndex, B),
3577 /*Local=*/true);
3578 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
3579 NoMerge = NoMerge || !CGF.CGM.getCodeGenOpts().OptimizationLevel ||
3580 (CGF.CurCodeDecl && CGF.CurCodeDecl->hasAttr<OptimizeNoneAttr>());
3581 if (NoMerge)
3582 HandlerCall->addFnAttr(llvm::Attribute::NoMerge);
3583 if (!MayReturn) {
3584 HandlerCall->setDoesNotReturn();
3585 CGF.Builder.CreateUnreachable();
3586 } else {
3587 CGF.Builder.CreateBr(ContBB);
3588 }
3589}
3590
3592 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3593 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3594 ArrayRef<llvm::Value *> DynamicArgs) {
3595 assert(IsSanitizerScope);
3596 assert(Checked.size() > 0);
3597 assert(CheckHandler >= 0 &&
3598 size_t(CheckHandler) < std::size(SanitizerHandlers));
3599 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3600
3601 llvm::Value *FatalCond = nullptr;
3602 llvm::Value *RecoverableCond = nullptr;
3603 llvm::Value *TrapCond = nullptr;
3604 bool NoMerge = false;
3605 for (int i = 0, n = Checked.size(); i < n; ++i) {
3606 llvm::Value *Check = Checked[i].first;
3607 // -fsanitize-trap= overrides -fsanitize-recover=.
3608 llvm::Value *&Cond =
3609 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3610 ? TrapCond
3611 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3612 ? RecoverableCond
3613 : FatalCond;
3614 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3615
3616 if (!CGM.getCodeGenOpts().SanitizeMergeHandlers.has(Checked[i].second))
3617 NoMerge = true;
3618 }
3619
3621 llvm::Value *Allow =
3622 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::allow_ubsan_check),
3623 llvm::ConstantInt::get(CGM.Int8Ty, CheckHandler));
3624
3625 for (llvm::Value **Cond : {&FatalCond, &RecoverableCond, &TrapCond}) {
3626 if (*Cond)
3627 *Cond = Builder.CreateOr(*Cond, Builder.CreateNot(Allow));
3628 }
3629 }
3630
3631 if (TrapCond)
3632 EmitTrapCheck(TrapCond, CheckHandler, NoMerge);
3633 if (!FatalCond && !RecoverableCond)
3634 return;
3635
3636 llvm::Value *JointCond;
3637 if (FatalCond && RecoverableCond)
3638 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3639 else
3640 JointCond = FatalCond ? FatalCond : RecoverableCond;
3641 assert(JointCond);
3642
3643 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3644 assert(SanOpts.has(Checked[0].second));
3645#ifndef NDEBUG
3646 for (int i = 1, n = Checked.size(); i < n; ++i) {
3647 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3648 "All recoverable kinds in a single check must be same!");
3649 assert(SanOpts.has(Checked[i].second));
3650 }
3651#endif
3652
3653 llvm::BasicBlock *Cont = createBasicBlock("cont");
3654 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3655 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3656 // Give hint that we very much don't expect to execute the handler
3657 llvm::MDBuilder MDHelper(getLLVMContext());
3658 llvm::MDNode *Node = MDHelper.createLikelyBranchWeights();
3659 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3660 EmitBlock(Handlers);
3661
3662 // Handler functions take an i8* pointing to the (handler-specific) static
3663 // information block, followed by a sequence of intptr_t arguments
3664 // representing operand values.
3667 if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3668 Args.reserve(DynamicArgs.size() + 1);
3669 ArgTypes.reserve(DynamicArgs.size() + 1);
3670
3671 // Emit handler arguments and create handler function type.
3672 if (!StaticArgs.empty()) {
3673 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3674 auto *InfoPtr = new llvm::GlobalVariable(
3675 CGM.getModule(), Info->getType(), false,
3676 llvm::GlobalVariable::PrivateLinkage, Info, "", nullptr,
3677 llvm::GlobalVariable::NotThreadLocal,
3678 CGM.getDataLayout().getDefaultGlobalsAddressSpace());
3679 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3681 Args.push_back(InfoPtr);
3682 ArgTypes.push_back(Args.back()->getType());
3683 }
3684
3685 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3686 Args.push_back(EmitCheckValue(DynamicArgs[i]));
3687 ArgTypes.push_back(IntPtrTy);
3688 }
3689 }
3690
3691 llvm::FunctionType *FnType =
3692 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3693
3694 if (!FatalCond || !RecoverableCond) {
3695 // Simple case: we need to generate a single handler call, either
3696 // fatal, or non-fatal.
3697 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3698 (FatalCond != nullptr), Cont, NoMerge);
3699 } else {
3700 // Emit two handler calls: first one for set of unrecoverable checks,
3701 // another one for recoverable.
3702 llvm::BasicBlock *NonFatalHandlerBB =
3703 createBasicBlock("non_fatal." + CheckName);
3704 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3705 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3706 EmitBlock(FatalHandlerBB);
3707 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3708 NonFatalHandlerBB, NoMerge);
3709 EmitBlock(NonFatalHandlerBB);
3710 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3711 Cont, NoMerge);
3712 }
3713
3714 EmitBlock(Cont);
3715}
3716
3718 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3719 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3720 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3721
3722 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3723 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3724
3725 llvm::MDBuilder MDHelper(getLLVMContext());
3726 llvm::MDNode *Node = MDHelper.createLikelyBranchWeights();
3727 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3728
3729 EmitBlock(CheckBB);
3730
3731 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3732
3733 llvm::CallInst *CheckCall;
3734 llvm::FunctionCallee SlowPathFn;
3735 if (WithDiag) {
3736 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3737 auto *InfoPtr =
3738 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3739 llvm::GlobalVariable::PrivateLinkage, Info);
3740 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3742
3743 SlowPathFn = CGM.getModule().getOrInsertFunction(
3744 "__cfi_slowpath_diag",
3745 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3746 false));
3747 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr, InfoPtr});
3748 } else {
3749 SlowPathFn = CGM.getModule().getOrInsertFunction(
3750 "__cfi_slowpath",
3751 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3752 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3753 }
3754
3756 cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3757 CheckCall->setDoesNotThrow();
3758
3759 EmitBlock(Cont);
3760}
3761
3762// Emit a stub for __cfi_check function so that the linker knows about this
3763// symbol in LTO mode.
3765 llvm::Module *M = &CGM.getModule();
3766 ASTContext &C = getContext();
3767 QualType QInt64Ty = C.getIntTypeForBitwidth(64, false);
3768
3770 ImplicitParamDecl ArgCallsiteTypeId(C, QInt64Ty, ImplicitParamKind::Other);
3771 ImplicitParamDecl ArgAddr(C, C.VoidPtrTy, ImplicitParamKind::Other);
3772 ImplicitParamDecl ArgCFICheckFailData(C, C.VoidPtrTy,
3774 FnArgs.push_back(&ArgCallsiteTypeId);
3775 FnArgs.push_back(&ArgAddr);
3776 FnArgs.push_back(&ArgCFICheckFailData);
3777 const CGFunctionInfo &FI =
3779
3780 llvm::Function *F = llvm::Function::Create(
3781 llvm::FunctionType::get(VoidTy, {Int64Ty, VoidPtrTy, VoidPtrTy}, false),
3782 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3783 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F, /*IsThunk=*/false);
3785 F->setAlignment(llvm::Align(4096));
3786 CGM.setDSOLocal(F);
3787
3788 llvm::LLVMContext &Ctx = M->getContext();
3789 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3790 // CrossDSOCFI pass is not executed if there is no executable code.
3791 SmallVector<llvm::Value*> Args{F->getArg(2), F->getArg(1)};
3792 llvm::CallInst::Create(M->getFunction("__cfi_check_fail"), Args, "", BB);
3793 llvm::ReturnInst::Create(Ctx, nullptr, BB);
3794}
3795
3796// This function is basically a switch over the CFI failure kind, which is
3797// extracted from CFICheckFailData (1st function argument). Each case is either
3798// llvm.trap or a call to one of the two runtime handlers, based on
3799// -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3800// failure kind) traps, but this should really never happen. CFICheckFailData
3801// can be nullptr if the calling module has -fsanitize-trap behavior for this
3802// check kind; in this case __cfi_check_fail traps as well.
3804 SanitizerScope SanScope(this);
3805 FunctionArgList Args;
3810 Args.push_back(&ArgData);
3811 Args.push_back(&ArgAddr);
3812
3813 const CGFunctionInfo &FI =
3815
3816 llvm::Function *F = llvm::Function::Create(
3817 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3818 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3819
3820 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F, /*IsThunk=*/false);
3822 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3823
3824 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3825 SourceLocation());
3826
3827 // This function is not affected by NoSanitizeList. This function does
3828 // not have a source location, but "src:*" would still apply. Revert any
3829 // changes to SanOpts made in StartFunction.
3831
3832 llvm::Value *Data =
3833 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3834 CGM.getContext().VoidPtrTy, ArgData.getLocation());
3835 llvm::Value *Addr =
3836 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3837 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3838
3839 // Data == nullptr means the calling module has trap behaviour for this check.
3840 llvm::Value *DataIsNotNullPtr =
3841 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3842 EmitTrapCheck(DataIsNotNullPtr, SanitizerHandler::CFICheckFail);
3843
3844 llvm::StructType *SourceLocationTy =
3845 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3846 llvm::StructType *CfiCheckFailDataTy =
3847 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3848
3849 llvm::Value *V = Builder.CreateConstGEP2_32(
3850 CfiCheckFailDataTy, Builder.CreatePointerCast(Data, UnqualPtrTy), 0, 0);
3851
3852 Address CheckKindAddr(V, Int8Ty, getIntAlign());
3853 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3854
3855 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3857 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3858 llvm::Value *ValidVtable = Builder.CreateZExt(
3859 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3860 {Addr, AllVtables}),
3861 IntPtrTy);
3862
3863 const std::pair<int, SanitizerMask> CheckKinds[] = {
3864 {CFITCK_VCall, SanitizerKind::CFIVCall},
3865 {CFITCK_NVCall, SanitizerKind::CFINVCall},
3866 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3867 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3868 {CFITCK_ICall, SanitizerKind::CFIICall}};
3869
3871 for (auto CheckKindMaskPair : CheckKinds) {
3872 int Kind = CheckKindMaskPair.first;
3873 SanitizerMask Mask = CheckKindMaskPair.second;
3874 llvm::Value *Cond =
3875 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3876 if (CGM.getLangOpts().Sanitize.has(Mask))
3877 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3878 {Data, Addr, ValidVtable});
3879 else
3880 EmitTrapCheck(Cond, SanitizerHandler::CFICheckFail);
3881 }
3882
3884 // The only reference to this function will be created during LTO link.
3885 // Make sure it survives until then.
3886 CGM.addUsedGlobal(F);
3887}
3888
3890 if (SanOpts.has(SanitizerKind::Unreachable)) {
3891 SanitizerScope SanScope(this);
3892 EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3893 SanitizerKind::Unreachable),
3894 SanitizerHandler::BuiltinUnreachable,
3896 }
3897 Builder.CreateUnreachable();
3898}
3899
3900void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked,
3901 SanitizerHandler CheckHandlerID,
3902 bool NoMerge) {
3903 llvm::BasicBlock *Cont = createBasicBlock("cont");
3904
3905 // If we're optimizing, collapse all calls to trap down to just one per
3906 // check-type per function to save on code size.
3907 if ((int)TrapBBs.size() <= CheckHandlerID)
3908 TrapBBs.resize(CheckHandlerID + 1);
3909
3910 llvm::BasicBlock *&TrapBB = TrapBBs[CheckHandlerID];
3911
3912 NoMerge = NoMerge || !CGM.getCodeGenOpts().OptimizationLevel ||
3913 (CurCodeDecl && CurCodeDecl->hasAttr<OptimizeNoneAttr>());
3914
3915 if (TrapBB && !NoMerge) {
3916 auto Call = TrapBB->begin();
3917 assert(isa<llvm::CallInst>(Call) && "Expected call in trap BB");
3918
3919 Call->applyMergedLocation(Call->getDebugLoc(),
3920 Builder.getCurrentDebugLocation());
3921 Builder.CreateCondBr(Checked, Cont, TrapBB);
3922 } else {
3923 TrapBB = createBasicBlock("trap");
3924 Builder.CreateCondBr(Checked, Cont, TrapBB);
3925 EmitBlock(TrapBB);
3926
3927 llvm::CallInst *TrapCall =
3928 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::ubsantrap),
3929 llvm::ConstantInt::get(CGM.Int8Ty, CheckHandlerID));
3930
3931 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3932 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3934 TrapCall->addFnAttr(A);
3935 }
3936 if (NoMerge)
3937 TrapCall->addFnAttr(llvm::Attribute::NoMerge);
3938 TrapCall->setDoesNotReturn();
3939 TrapCall->setDoesNotThrow();
3940 Builder.CreateUnreachable();
3941 }
3942
3943 EmitBlock(Cont);
3944}
3945
3946llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
3947 llvm::CallInst *TrapCall =
3948 Builder.CreateCall(CGM.getIntrinsic(IntrID));
3949
3950 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3951 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3953 TrapCall->addFnAttr(A);
3954 }
3955
3957 TrapCall->addFnAttr(llvm::Attribute::NoMerge);
3958 return TrapCall;
3959}
3960
3962 LValueBaseInfo *BaseInfo,
3963 TBAAAccessInfo *TBAAInfo) {
3964 assert(E->getType()->isArrayType() &&
3965 "Array to pointer decay must have array source type!");
3966
3967 // Expressions of array type can't be bitfields or vector elements.
3968 LValue LV = EmitLValue(E);
3969 Address Addr = LV.getAddress();
3970
3971 // If the array type was an incomplete type, we need to make sure
3972 // the decay ends up being the right type.
3973 llvm::Type *NewTy = ConvertType(E->getType());
3974 Addr = Addr.withElementType(NewTy);
3975
3976 // Note that VLA pointers are always decayed, so we don't need to do
3977 // anything here.
3978 if (!E->getType()->isVariableArrayType()) {
3979 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3980 "Expected pointer to array");
3981 Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3982 }
3983
3984 // The result of this decay conversion points to an array element within the
3985 // base lvalue. However, since TBAA currently does not support representing
3986 // accesses to elements of member arrays, we conservatively represent accesses
3987 // to the pointee object as if it had no any base lvalue specified.
3988 // TODO: Support TBAA for member arrays.
3990 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3991 if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3992
3993 return Addr.withElementType(ConvertTypeForMem(EltType));
3994}
3995
3996/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3997/// array to pointer, return the array subexpression.
3998static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3999 // If this isn't just an array->pointer decay, bail out.
4000 const auto *CE = dyn_cast<CastExpr>(E);
4001 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
4002 return nullptr;
4003
4004 // If this is a decay from variable width array, bail out.
4005 const Expr *SubExpr = CE->getSubExpr();
4006 if (SubExpr->getType()->isVariableArrayType())
4007 return nullptr;
4008
4009 return SubExpr;
4010}
4011
4013 llvm::Type *elemType,
4014 llvm::Value *ptr,
4015 ArrayRef<llvm::Value*> indices,
4016 bool inbounds,
4017 bool signedIndices,
4018 SourceLocation loc,
4019 const llvm::Twine &name = "arrayidx") {
4020 if (inbounds) {
4021 return CGF.EmitCheckedInBoundsGEP(elemType, ptr, indices, signedIndices,
4023 name);
4024 } else {
4025 return CGF.Builder.CreateGEP(elemType, ptr, indices, name);
4026 }
4027}
4028
4031 llvm::Type *elementType, bool inbounds,
4032 bool signedIndices, SourceLocation loc,
4033 CharUnits align,
4034 const llvm::Twine &name = "arrayidx") {
4035 if (inbounds) {
4036 return CGF.EmitCheckedInBoundsGEP(addr, indices, elementType, signedIndices,
4038 align, name);
4039 } else {
4040 return CGF.Builder.CreateGEP(addr, indices, elementType, align, name);
4041 }
4042}
4043
4045 llvm::Value *idx,
4046 CharUnits eltSize) {
4047 // If we have a constant index, we can use the exact offset of the
4048 // element we're accessing.
4049 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
4050 CharUnits offset = constantIdx->getZExtValue() * eltSize;
4051 return arrayAlign.alignmentAtOffset(offset);
4052
4053 // Otherwise, use the worst-case alignment for any element.
4054 } else {
4055 return arrayAlign.alignmentOfArrayElement(eltSize);
4056 }
4057}
4058
4060 const VariableArrayType *vla) {
4061 QualType eltType;
4062 do {
4063 eltType = vla->getElementType();
4064 } while ((vla = ctx.getAsVariableArrayType(eltType)));
4065 return eltType;
4066}
4067
4069 return D && D->hasAttr<BPFPreserveStaticOffsetAttr>();
4070}
4071
4072static bool hasBPFPreserveStaticOffset(const Expr *E) {
4073 if (!E)
4074 return false;
4075 QualType PointeeType = E->getType()->getPointeeType();
4076 if (PointeeType.isNull())
4077 return false;
4078 if (const auto *BaseDecl = PointeeType->getAsRecordDecl())
4079 return hasBPFPreserveStaticOffset(BaseDecl);
4080 return false;
4081}
4082
4083// Wraps Addr with a call to llvm.preserve.static.offset intrinsic.
4085 Address &Addr) {
4086 if (!CGF.getTarget().getTriple().isBPF())
4087 return Addr;
4088
4089 llvm::Function *Fn =
4090 CGF.CGM.getIntrinsic(llvm::Intrinsic::preserve_static_offset);
4091 llvm::CallInst *Call = CGF.Builder.CreateCall(Fn, {Addr.emitRawPointer(CGF)});
4092 return Address(Call, Addr.getElementType(), Addr.getAlignment());
4093}
4094
4095/// Given an array base, check whether its member access belongs to a record
4096/// with preserve_access_index attribute or not.
4097static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) {
4098 if (!ArrayBase || !CGF.getDebugInfo())
4099 return false;
4100
4101 // Only support base as either a MemberExpr or DeclRefExpr.
4102 // DeclRefExpr to cover cases like:
4103 // struct s { int a; int b[10]; };
4104 // struct s *p;
4105 // p[1].a
4106 // p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr.
4107 // p->b[5] is a MemberExpr example.
4108 const Expr *E = ArrayBase->IgnoreImpCasts();
4109 if (const auto *ME = dyn_cast<MemberExpr>(E))
4110 return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
4111
4112 if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
4113 const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl());
4114 if (!VarDef)
4115 return false;
4116
4117 const auto *PtrT = VarDef->getType()->getAs<PointerType>();
4118 if (!PtrT)
4119 return false;
4120
4121 const auto *PointeeT = PtrT->getPointeeType()
4123 if (const auto *RecT = dyn_cast<RecordType>(PointeeT))
4124 return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
4125 return false;
4126 }
4127
4128 return false;
4129}
4130
4133 QualType eltType, bool inbounds,
4134 bool signedIndices, SourceLocation loc,
4135 QualType *arrayType = nullptr,
4136 const Expr *Base = nullptr,
4137 const llvm::Twine &name = "arrayidx") {
4138 // All the indices except that last must be zero.
4139#ifndef NDEBUG
4140 for (auto *idx : indices.drop_back())
4141 assert(isa<llvm::ConstantInt>(idx) &&
4142 cast<llvm::ConstantInt>(idx)->isZero());
4143#endif
4144
4145 // Determine the element size of the statically-sized base. This is
4146 // the thing that the indices are expressed in terms of.
4147 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
4148 eltType = getFixedSizeElementType(CGF.getContext(), vla);
4149 }
4150
4151 // We can use that to compute the best alignment of the element.
4152 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
4153 CharUnits eltAlign =
4154 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
4155
4157 addr = wrapWithBPFPreserveStaticOffset(CGF, addr);
4158
4159 llvm::Value *eltPtr;
4160 auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
4161 if (!LastIndex ||
4163 addr = emitArraySubscriptGEP(CGF, addr, indices,
4164 CGF.ConvertTypeForMem(eltType), inbounds,
4165 signedIndices, loc, eltAlign, name);
4166 return addr;
4167 } else {
4168 // Remember the original array subscript for bpf target
4169 unsigned idx = LastIndex->getZExtValue();
4170 llvm::DIType *DbgInfo = nullptr;
4171 if (arrayType)
4172 DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc);
4173 eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(
4174 addr.getElementType(), addr.emitRawPointer(CGF), indices.size() - 1,
4175 idx, DbgInfo);
4176 }
4177
4178 return Address(eltPtr, CGF.ConvertTypeForMem(eltType), eltAlign);
4179}
4180
4181/// The offset of a field from the beginning of the record.
4183 const FieldDecl *Field, int64_t &Offset) {
4184 ASTContext &Ctx = CGF.getContext();
4185 const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(RD);
4186 unsigned FieldNo = 0;
4187
4188 for (const FieldDecl *FD : RD->fields()) {
4189 if (FD == Field) {
4190 Offset += Layout.getFieldOffset(FieldNo);
4191 return true;
4192 }
4193
4194 QualType Ty = FD->getType();
4195 if (Ty->isRecordType())
4196 if (getFieldOffsetInBits(CGF, Ty->getAsRecordDecl(), Field, Offset)) {
4197 Offset += Layout.getFieldOffset(FieldNo);
4198 return true;
4199 }
4200
4201 if (!RD->isUnion())
4202 ++FieldNo;
4203 }
4204
4205 return false;
4206}
4207
4208/// Returns the relative offset difference between \p FD1 and \p FD2.
4209/// \code
4210/// offsetof(struct foo, FD1) - offsetof(struct foo, FD2)
4211/// \endcode
4212/// Both fields must be within the same struct.
4213static std::optional<int64_t> getOffsetDifferenceInBits(CodeGenFunction &CGF,
4214 const FieldDecl *FD1,
4215 const FieldDecl *FD2) {
4216 const RecordDecl *FD1OuterRec =
4218 const RecordDecl *FD2OuterRec =
4220
4221 if (FD1OuterRec != FD2OuterRec)
4222 // Fields must be within the same RecordDecl.
4223 return std::optional<int64_t>();
4224
4225 int64_t FD1Offset = 0;
4226 if (!getFieldOffsetInBits(CGF, FD1OuterRec, FD1, FD1Offset))
4227 return std::optional<int64_t>();
4228
4229 int64_t FD2Offset = 0;
4230 if (!getFieldOffsetInBits(CGF, FD2OuterRec, FD2, FD2Offset))
4231 return std::optional<int64_t>();
4232
4233 return std::make_optional<int64_t>(FD1Offset - FD2Offset);
4234}
4235
4237 bool Accessed) {
4238 // The index must always be an integer, which is not an aggregate. Emit it
4239 // in lexical order (this complexity is, sadly, required by C++17).
4240 llvm::Value *IdxPre =
4241 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
4242 bool SignedIndices = false;
4243 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
4244 auto *Idx = IdxPre;
4245 if (E->getLHS() != E->getIdx()) {
4246 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
4247 Idx = EmitScalarExpr(E->getIdx());
4248 }
4249
4250 QualType IdxTy = E->getIdx()->getType();
4251 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
4252 SignedIndices |= IdxSigned;
4253
4254 if (SanOpts.has(SanitizerKind::ArrayBounds))
4255 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
4256
4257 // Extend or truncate the index type to 32 or 64-bits.
4258 if (Promote && Idx->getType() != IntPtrTy)
4259 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
4260
4261 return Idx;
4262 };
4263 IdxPre = nullptr;
4264
4265 // If the base is a vector type, then we are forming a vector element lvalue
4266 // with this subscript.
4267 if (E->getBase()->getType()->isSubscriptableVectorType() &&
4268 !isa<ExtVectorElementExpr>(E->getBase())) {
4269 // Emit the vector as an lvalue to get its address.
4270 LValue LHS = EmitLValue(E->getBase());
4271 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
4272 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
4273 return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
4274 LHS.getBaseInfo(), TBAAAccessInfo());
4275 }
4276
4277 // All the other cases basically behave like simple offsetting.
4278
4279 // Handle the extvector case we ignored above.
4280 if (isa<ExtVectorElementExpr>(E->getBase())) {
4281 LValue LV = EmitLValue(E->getBase());
4282 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4284
4285 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
4286 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
4287 SignedIndices, E->getExprLoc());
4288 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
4289 CGM.getTBAAInfoForSubobject(LV, EltType));
4290 }
4291
4292 LValueBaseInfo EltBaseInfo;
4293 TBAAAccessInfo EltTBAAInfo;
4294 Address Addr = Address::invalid();
4295 if (const VariableArrayType *vla =
4296 getContext().getAsVariableArrayType(E->getType())) {
4297 // The base must be a pointer, which is not an aggregate. Emit
4298 // it. It needs to be emitted first in case it's what captures
4299 // the VLA bounds.
4300 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4301 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4302
4303 // The element count here is the total number of non-VLA elements.
4304 llvm::Value *numElements = getVLASize(vla).NumElts;
4305
4306 // Effectively, the multiply by the VLA size is part of the GEP.
4307 // GEP indexes are signed, and scaling an index isn't permitted to
4308 // signed-overflow, so we use the same semantics for our explicit
4309 // multiply. We suppress this if overflow is not undefined behavior.
4310 if (getLangOpts().isSignedOverflowDefined()) {
4311 Idx = Builder.CreateMul(Idx, numElements);
4312 } else {
4313 Idx = Builder.CreateNSWMul(Idx, numElements);
4314 }
4315
4316 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
4317 !getLangOpts().isSignedOverflowDefined(),
4318 SignedIndices, E->getExprLoc());
4319
4320 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
4321 // Indexing over an interface, as in "NSString *P; P[4];"
4322
4323 // Emit the base pointer.
4324 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4325 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4326
4327 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
4328 llvm::Value *InterfaceSizeVal =
4329 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
4330
4331 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
4332
4333 // We don't necessarily build correct LLVM struct types for ObjC
4334 // interfaces, so we can't rely on GEP to do this scaling
4335 // correctly, so we need to cast to i8*. FIXME: is this actually
4336 // true? A lot of other things in the fragile ABI would break...
4337 llvm::Type *OrigBaseElemTy = Addr.getElementType();
4338
4339 // Do the GEP.
4340 CharUnits EltAlign =
4341 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
4342 llvm::Value *EltPtr =
4343 emitArraySubscriptGEP(*this, Int8Ty, Addr.emitRawPointer(*this),
4344 ScaledIdx, false, SignedIndices, E->getExprLoc());
4345 Addr = Address(EltPtr, OrigBaseElemTy, EltAlign);
4346 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
4347 // If this is A[i] where A is an array, the frontend will have decayed the
4348 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
4349 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
4350 // "gep x, i" here. Emit one "gep A, 0, i".
4351 assert(Array->getType()->isArrayType() &&
4352 "Array to pointer decay must have array source type!");
4353 LValue ArrayLV;
4354 // For simple multidimensional array indexing, set the 'accessed' flag for
4355 // better bounds-checking of the base expression.
4356 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
4357 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
4358 else
4359 ArrayLV = EmitLValue(Array);
4360 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4361
4362 if (SanOpts.has(SanitizerKind::ArrayBounds)) {
4363 // If the array being accessed has a "counted_by" attribute, generate
4364 // bounds checking code. The "count" field is at the top level of the
4365 // struct or in an anonymous struct, that's also at the top level. Future
4366 // expansions may allow the "count" to reside at any place in the struct,
4367 // but the value of "counted_by" will be a "simple" path to the count,
4368 // i.e. "a.b.count", so we shouldn't need the full force of EmitLValue or
4369 // similar to emit the correct GEP.
4370 const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
4371 getLangOpts().getStrictFlexArraysLevel();
4372
4373 if (const auto *ME = dyn_cast<MemberExpr>(Array);
4374 ME &&
4375 ME->isFlexibleArrayMemberLike(getContext(), StrictFlexArraysLevel) &&
4377 const FieldDecl *FAMDecl = cast<FieldDecl>(ME->getMemberDecl());
4378 if (const FieldDecl *CountFD = FAMDecl->findCountedByField()) {
4379 if (std::optional<int64_t> Diff =
4380 getOffsetDifferenceInBits(*this, CountFD, FAMDecl)) {
4381 CharUnits OffsetDiff = CGM.getContext().toCharUnitsFromBits(*Diff);
4382
4383 // Create a GEP with a byte offset between the FAM and count and
4384 // use that to load the count value.
4386 ArrayLV.getAddress(), Int8PtrTy, Int8Ty);
4387
4388 llvm::Type *CountTy = ConvertType(CountFD->getType());
4389 llvm::Value *Res = Builder.CreateInBoundsGEP(
4390 Int8Ty, Addr.emitRawPointer(*this),
4391 Builder.getInt32(OffsetDiff.getQuantity()), ".counted_by.gep");
4392 Res = Builder.CreateAlignedLoad(CountTy, Res, getIntAlign(),
4393 ".counted_by.load");
4394
4395 // Now emit the bounds checking.
4396 EmitBoundsCheckImpl(E, Res, Idx, E->getIdx()->getType(),
4397 Array->getType(), Accessed);
4398 }
4399 }
4400 }
4401 }
4402
4403 // Propagate the alignment from the array itself to the result.
4404 QualType arrayType = Array->getType();
4405 Addr = emitArraySubscriptGEP(
4406 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
4407 E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
4408 E->getExprLoc(), &arrayType, E->getBase());
4409 EltBaseInfo = ArrayLV.getBaseInfo();
4410 EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
4411 } else {
4412 // The base must be a pointer; emit it with an estimate of its alignment.
4413 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4414 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4415 QualType ptrType = E->getBase()->getType();
4416 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
4417 !getLangOpts().isSignedOverflowDefined(),
4418 SignedIndices, E->getExprLoc(), &ptrType,
4419 E->getBase());
4420 }
4421
4422 LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
4423
4424 if (getLangOpts().ObjC &&
4425 getLangOpts().getGC() != LangOptions::NonGC) {
4428 }
4429 return LV;
4430}