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 "CodeGenPGO.h"
25 #include "ConstantEmitter.h"
26 #include "TargetInfo.h"
27 #include "clang/AST/ASTContext.h"
28 #include "clang/AST/ASTLambda.h"
29 #include "clang/AST/Attr.h"
30 #include "clang/AST/DeclObjC.h"
31 #include "clang/AST/NSAPI.h"
32 #include "clang/AST/StmtVisitor.h"
33 #include "clang/Basic/Builtins.h"
34 #include "clang/Basic/CodeGenOptions.h"
35 #include "clang/Basic/Module.h"
36 #include "clang/Basic/SourceManager.h"
37 #include "llvm/ADT/STLExtras.h"
38 #include "llvm/ADT/ScopeExit.h"
39 #include "llvm/ADT/StringExtras.h"
40 #include "llvm/IR/DataLayout.h"
41 #include "llvm/IR/Intrinsics.h"
42 #include "llvm/IR/LLVMContext.h"
43 #include "llvm/IR/MDBuilder.h"
44 #include "llvm/IR/MatrixBuilder.h"
45 #include "llvm/Support/ConvertUTF.h"
46 #include "llvm/Support/Endian.h"
47 #include "llvm/Support/MathExtras.h"
48 #include "llvm/Support/Path.h"
49 #include "llvm/Support/xxhash.h"
50 #include "llvm/Transforms/Utils/SanitizerStats.h"
51
52 #include <numeric>
53 #include <optional>
54 #include <string>
55
56 using namespace clang;
57 using namespace CodeGen;
58
59 namespace clang {
60 // TODO: consider deprecating ClSanitizeGuardChecks; functionality is subsumed
61 // by -fsanitize-skip-hot-cutoff
62 llvm::cl::opt<bool> ClSanitizeGuardChecks(
63 "ubsan-guard-checks", llvm::cl::Optional,
64 llvm::cl::desc("Guard UBSAN checks with `llvm.allow.ubsan.check()`."));
65
66 } // namespace clang
67
68 //===--------------------------------------------------------------------===//
69 // Defines for metadata
70 //===--------------------------------------------------------------------===//
71
72 // Those values are crucial to be the SAME as in ubsan runtime library.
73 enum VariableTypeDescriptorKind : uint16_t {
74 /// An integer type.
75 TK_Integer = 0x0000,
76 /// A floating-point type.
77 TK_Float = 0x0001,
78 /// An _BitInt(N) type.
79 TK_BitInt = 0x0002,
80 /// Any other type. The value representation is unspecified.
81 TK_Unknown = 0xffff
82 };
83
84 //===--------------------------------------------------------------------===//
85 // Miscellaneous Helper Methods
86 //===--------------------------------------------------------------------===//
87
88 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
89 /// block.
90 RawAddress
CreateTempAllocaWithoutCast(llvm::Type * Ty,CharUnits Align,const Twine & Name,llvm::Value * ArraySize)91 CodeGenFunction::CreateTempAllocaWithoutCast(llvm::Type *Ty, CharUnits Align,
92 const Twine &Name,
93 llvm::Value *ArraySize) {
94 auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
95 Alloca->setAlignment(Align.getAsAlign());
96 return RawAddress(Alloca, Ty, Align, KnownNonNull);
97 }
98
CreateTempAlloca(llvm::Type * Ty,LangAS DestLangAS,CharUnits Align,const Twine & Name,llvm::Value * ArraySize,RawAddress * AllocaAddr)99 RawAddress CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, LangAS DestLangAS,
100 CharUnits Align, const Twine &Name,
101 llvm::Value *ArraySize,
102 RawAddress *AllocaAddr) {
103 RawAddress Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
104 if (AllocaAddr)
105 *AllocaAddr = Alloca;
106 llvm::Value *V = Alloca.getPointer();
107 // Alloca always returns a pointer in alloca address space, which may
108 // be different from the type defined by the language. For example,
109 // in C++ the auto variables are in the default address space. Therefore
110 // cast alloca to the default address space when necessary.
111
112 unsigned DestAddrSpace = getContext().getTargetAddressSpace(DestLangAS);
113 if (DestAddrSpace != Alloca.getAddressSpace()) {
114 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
115 // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
116 // otherwise alloca is inserted at the current insertion point of the
117 // builder.
118 if (!ArraySize)
119 Builder.SetInsertPoint(getPostAllocaInsertPoint());
120 V = getTargetHooks().performAddrSpaceCast(
121 *this, V, getASTAllocaAddressSpace(), Builder.getPtrTy(DestAddrSpace),
122 /*IsNonNull=*/true);
123 }
124
125 return RawAddress(V, Ty, Align, KnownNonNull);
126 }
127
128 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
129 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
130 /// insertion point of the builder.
CreateTempAlloca(llvm::Type * Ty,const Twine & Name,llvm::Value * ArraySize)131 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
132 const Twine &Name,
133 llvm::Value *ArraySize) {
134 llvm::AllocaInst *Alloca;
135 if (ArraySize)
136 Alloca = Builder.CreateAlloca(Ty, ArraySize, Name);
137 else
138 Alloca =
139 new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
140 ArraySize, Name, AllocaInsertPt->getIterator());
141 if (SanOpts.Mask & SanitizerKind::Address) {
142 Alloca->addAnnotationMetadata({"alloca_name_altered", Name.str()});
143 }
144 if (Allocas) {
145 Allocas->Add(Alloca);
146 }
147 return Alloca;
148 }
149
150 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
151 /// default alignment of the corresponding LLVM type, which is *not*
152 /// guaranteed to be related in any way to the expected alignment of
153 /// an AST type that might have been lowered to Ty.
CreateDefaultAlignTempAlloca(llvm::Type * Ty,const Twine & Name)154 RawAddress CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
155 const Twine &Name) {
156 CharUnits Align =
157 CharUnits::fromQuantity(CGM.getDataLayout().getPrefTypeAlign(Ty));
158 return CreateTempAlloca(Ty, Align, Name);
159 }
160
CreateIRTemp(QualType Ty,const Twine & Name)161 RawAddress CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
162 CharUnits Align = getContext().getTypeAlignInChars(Ty);
163 return CreateTempAlloca(ConvertType(Ty), Align, Name);
164 }
165
CreateMemTemp(QualType Ty,const Twine & Name,RawAddress * Alloca)166 RawAddress CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name,
167 RawAddress *Alloca) {
168 // FIXME: Should we prefer the preferred type alignment here?
169 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
170 }
171
CreateMemTemp(QualType Ty,CharUnits Align,const Twine & Name,RawAddress * Alloca)172 RawAddress CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
173 const Twine &Name,
174 RawAddress *Alloca) {
175 RawAddress Result = CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
176 /*ArraySize=*/nullptr, Alloca);
177
178 if (Ty->isConstantMatrixType()) {
179 auto *ArrayTy = cast<llvm::ArrayType>(Result.getElementType());
180 auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
181 ArrayTy->getNumElements());
182
183 Result = Address(Result.getPointer(), VectorTy, Result.getAlignment(),
184 KnownNonNull);
185 }
186 return Result;
187 }
188
CreateMemTempWithoutCast(QualType Ty,CharUnits Align,const Twine & Name)189 RawAddress CodeGenFunction::CreateMemTempWithoutCast(QualType Ty,
190 CharUnits Align,
191 const Twine &Name) {
192 return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
193 }
194
CreateMemTempWithoutCast(QualType Ty,const Twine & Name)195 RawAddress CodeGenFunction::CreateMemTempWithoutCast(QualType Ty,
196 const Twine &Name) {
197 return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
198 Name);
199 }
200
201 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
202 /// expression and compare the result against zero, returning an Int1Ty value.
EvaluateExprAsBool(const Expr * E)203 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
204 PGO->setCurrentStmt(E);
205 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
206 llvm::Value *MemPtr = EmitScalarExpr(E);
207 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
208 }
209
210 QualType BoolTy = getContext().BoolTy;
211 SourceLocation Loc = E->getExprLoc();
212 CGFPOptionsRAII FPOptsRAII(*this, E);
213 if (!E->getType()->isAnyComplexType())
214 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
215
216 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
217 Loc);
218 }
219
220 /// EmitIgnoredExpr - Emit code to compute the specified expression,
221 /// ignoring the result.
EmitIgnoredExpr(const Expr * E)222 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
223 if (E->isPRValue())
224 return (void)EmitAnyExpr(E, AggValueSlot::ignored(), true);
225
226 // if this is a bitfield-resulting conditional operator, we can special case
227 // emit this. The normal 'EmitLValue' version of this is particularly
228 // difficult to codegen for, since creating a single "LValue" for two
229 // different sized arguments here is not particularly doable.
230 if (const auto *CondOp = dyn_cast<AbstractConditionalOperator>(
231 E->IgnoreParenNoopCasts(getContext()))) {
232 if (CondOp->getObjectKind() == OK_BitField)
233 return EmitIgnoredConditionalOperator(CondOp);
234 }
235
236 // Just emit it as an l-value and drop the result.
237 EmitLValue(E);
238 }
239
240 /// EmitAnyExpr - Emit code to compute the specified expression which
241 /// can have any type. The result is returned as an RValue struct.
242 /// If this is an aggregate expression, AggSlot indicates where the
243 /// result should be returned.
EmitAnyExpr(const Expr * E,AggValueSlot aggSlot,bool ignoreResult)244 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
245 AggValueSlot aggSlot,
246 bool ignoreResult) {
247 switch (getEvaluationKind(E->getType())) {
248 case TEK_Scalar:
249 return RValue::get(EmitScalarExpr(E, ignoreResult));
250 case TEK_Complex:
251 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
252 case TEK_Aggregate:
253 if (!ignoreResult && aggSlot.isIgnored())
254 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
255 EmitAggExpr(E, aggSlot);
256 return aggSlot.asRValue();
257 }
258 llvm_unreachable("bad evaluation kind");
259 }
260
261 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
262 /// always be accessible even if no aggregate location is provided.
EmitAnyExprToTemp(const Expr * E)263 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
264 AggValueSlot AggSlot = AggValueSlot::ignored();
265
266 if (hasAggregateEvaluationKind(E->getType()))
267 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
268 return EmitAnyExpr(E, AggSlot);
269 }
270
271 /// EmitAnyExprToMem - Evaluate an expression into a given memory
272 /// location.
EmitAnyExprToMem(const Expr * E,Address Location,Qualifiers Quals,bool IsInit)273 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
274 Address Location,
275 Qualifiers Quals,
276 bool IsInit) {
277 // FIXME: This function should take an LValue as an argument.
278 switch (getEvaluationKind(E->getType())) {
279 case TEK_Complex:
280 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
281 /*isInit*/ false);
282 return;
283
284 case TEK_Aggregate: {
285 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
286 AggValueSlot::IsDestructed_t(IsInit),
287 AggValueSlot::DoesNotNeedGCBarriers,
288 AggValueSlot::IsAliased_t(!IsInit),
289 AggValueSlot::MayOverlap));
290 return;
291 }
292
293 case TEK_Scalar: {
294 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
295 LValue LV = MakeAddrLValue(Location, E->getType());
296 EmitStoreThroughLValue(RV, LV);
297 return;
298 }
299 }
300 llvm_unreachable("bad evaluation kind");
301 }
302
EmitInitializationToLValue(const Expr * E,LValue LV,AggValueSlot::IsZeroed_t IsZeroed)303 void CodeGenFunction::EmitInitializationToLValue(
304 const Expr *E, LValue LV, AggValueSlot::IsZeroed_t IsZeroed) {
305 QualType Type = LV.getType();
306 switch (getEvaluationKind(Type)) {
307 case TEK_Complex:
308 EmitComplexExprIntoLValue(E, LV, /*isInit*/ true);
309 return;
310 case TEK_Aggregate:
311 EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed,
312 AggValueSlot::DoesNotNeedGCBarriers,
313 AggValueSlot::IsNotAliased,
314 AggValueSlot::MayOverlap, IsZeroed));
315 return;
316 case TEK_Scalar:
317 if (LV.isSimple())
318 EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false);
319 else
320 EmitStoreThroughLValue(RValue::get(EmitScalarExpr(E)), LV);
321 return;
322 }
323 llvm_unreachable("bad evaluation kind");
324 }
325
326 static void
pushTemporaryCleanup(CodeGenFunction & CGF,const MaterializeTemporaryExpr * M,const Expr * E,Address ReferenceTemporary)327 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
328 const Expr *E, Address ReferenceTemporary) {
329 // Objective-C++ ARC:
330 // If we are binding a reference to a temporary that has ownership, we
331 // need to perform retain/release operations on the temporary.
332 //
333 // FIXME: This should be looking at E, not M.
334 if (auto Lifetime = M->getType().getObjCLifetime()) {
335 switch (Lifetime) {
336 case Qualifiers::OCL_None:
337 case Qualifiers::OCL_ExplicitNone:
338 // Carry on to normal cleanup handling.
339 break;
340
341 case Qualifiers::OCL_Autoreleasing:
342 // Nothing to do; cleaned up by an autorelease pool.
343 return;
344
345 case Qualifiers::OCL_Strong:
346 case Qualifiers::OCL_Weak:
347 switch (StorageDuration Duration = M->getStorageDuration()) {
348 case SD_Static:
349 // Note: we intentionally do not register a cleanup to release
350 // the object on program termination.
351 return;
352
353 case SD_Thread:
354 // FIXME: We should probably register a cleanup in this case.
355 return;
356
357 case SD_Automatic:
358 case SD_FullExpression:
359 CodeGenFunction::Destroyer *Destroy;
360 CleanupKind CleanupKind;
361 if (Lifetime == Qualifiers::OCL_Strong) {
362 const ValueDecl *VD = M->getExtendingDecl();
363 bool Precise = isa_and_nonnull<VarDecl>(VD) &&
364 VD->hasAttr<ObjCPreciseLifetimeAttr>();
365 CleanupKind = CGF.getARCCleanupKind();
366 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
367 : &CodeGenFunction::destroyARCStrongImprecise;
368 } else {
369 // __weak objects always get EH cleanups; otherwise, exceptions
370 // could cause really nasty crashes instead of mere leaks.
371 CleanupKind = NormalAndEHCleanup;
372 Destroy = &CodeGenFunction::destroyARCWeak;
373 }
374 if (Duration == SD_FullExpression)
375 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
376 M->getType(), *Destroy,
377 CleanupKind & EHCleanup);
378 else
379 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
380 M->getType(),
381 *Destroy, CleanupKind & EHCleanup);
382 return;
383
384 case SD_Dynamic:
385 llvm_unreachable("temporary cannot have dynamic storage duration");
386 }
387 llvm_unreachable("unknown storage duration");
388 }
389 }
390
391 QualType::DestructionKind DK = E->getType().isDestructedType();
392 if (DK != QualType::DK_none) {
393 switch (M->getStorageDuration()) {
394 case SD_Static:
395 case SD_Thread: {
396 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
397 if (const RecordType *RT =
398 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
399 // Get the destructor for the reference temporary.
400 if (auto *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl());
401 ClassDecl && !ClassDecl->hasTrivialDestructor())
402 ReferenceTemporaryDtor = ClassDecl->getDestructor();
403 }
404
405 if (!ReferenceTemporaryDtor)
406 return;
407
408 llvm::FunctionCallee CleanupFn;
409 llvm::Constant *CleanupArg;
410 if (E->getType()->isArrayType()) {
411 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
412 ReferenceTemporary, E->getType(), CodeGenFunction::destroyCXXObject,
413 CGF.getLangOpts().Exceptions,
414 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
415 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
416 } else {
417 CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
418 GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
419 CleanupArg =
420 cast<llvm::Constant>(ReferenceTemporary.emitRawPointer(CGF));
421 }
422 CGF.CGM.getCXXABI().registerGlobalDtor(
423 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
424 } break;
425 case SD_FullExpression:
426 CGF.pushDestroy(DK, ReferenceTemporary, E->getType());
427 break;
428 case SD_Automatic:
429 CGF.pushLifetimeExtendedDestroy(DK, ReferenceTemporary, E->getType());
430 break;
431 case SD_Dynamic:
432 llvm_unreachable("temporary cannot have dynamic storage duration");
433 }
434 }
435 }
436
createReferenceTemporary(CodeGenFunction & CGF,const MaterializeTemporaryExpr * M,const Expr * Inner,RawAddress * Alloca=nullptr)437 static RawAddress createReferenceTemporary(CodeGenFunction &CGF,
438 const MaterializeTemporaryExpr *M,
439 const Expr *Inner,
440 RawAddress *Alloca = nullptr) {
441 auto &TCG = CGF.getTargetHooks();
442 switch (M->getStorageDuration()) {
443 case SD_FullExpression:
444 case SD_Automatic: {
445 // If we have a constant temporary array or record try to promote it into a
446 // constant global under the same rules a normal constant would've been
447 // promoted. This is easier on the optimizer and generally emits fewer
448 // instructions.
449 QualType Ty = Inner->getType();
450 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
451 (Ty->isArrayType() || Ty->isRecordType()) &&
452 Ty.isConstantStorage(CGF.getContext(), true, false))
453 if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
454 auto AS = CGF.CGM.GetGlobalConstantAddressSpace();
455 auto *GV = new llvm::GlobalVariable(
456 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
457 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
458 llvm::GlobalValue::NotThreadLocal,
459 CGF.getContext().getTargetAddressSpace(AS));
460 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
461 GV->setAlignment(alignment.getAsAlign());
462 llvm::Constant *C = GV;
463 if (AS != LangAS::Default)
464 C = TCG.performAddrSpaceCast(
465 CGF.CGM, GV, AS,
466 llvm::PointerType::get(
467 CGF.getLLVMContext(),
468 CGF.getContext().getTargetAddressSpace(LangAS::Default)));
469 // FIXME: Should we put the new global into a COMDAT?
470 return RawAddress(C, GV->getValueType(), alignment);
471 }
472 return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
473 }
474 case SD_Thread:
475 case SD_Static:
476 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
477
478 case SD_Dynamic:
479 llvm_unreachable("temporary can't have dynamic storage duration");
480 }
481 llvm_unreachable("unknown storage duration");
482 }
483
484 /// Helper method to check if the underlying ABI is AAPCS
isAAPCS(const TargetInfo & TargetInfo)485 static bool isAAPCS(const TargetInfo &TargetInfo) {
486 return TargetInfo.getABI().starts_with("aapcs");
487 }
488
489 LValue CodeGenFunction::
EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr * M)490 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
491 const Expr *E = M->getSubExpr();
492
493 assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
494 !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
495 "Reference should never be pseudo-strong!");
496
497 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
498 // as that will cause the lifetime adjustment to be lost for ARC
499 auto ownership = M->getType().getObjCLifetime();
500 if (ownership != Qualifiers::OCL_None &&
501 ownership != Qualifiers::OCL_ExplicitNone) {
502 RawAddress Object = createReferenceTemporary(*this, M, E);
503 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
504 llvm::Type *Ty = ConvertTypeForMem(E->getType());
505 Object = Object.withElementType(Ty);
506
507 // createReferenceTemporary will promote the temporary to a global with a
508 // constant initializer if it can. It can only do this to a value of
509 // ARC-manageable type if the value is global and therefore "immune" to
510 // ref-counting operations. Therefore we have no need to emit either a
511 // dynamic initialization or a cleanup and we can just return the address
512 // of the temporary.
513 if (Var->hasInitializer())
514 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
515
516 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
517 }
518 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
519 AlignmentSource::Decl);
520
521 switch (getEvaluationKind(E->getType())) {
522 default: llvm_unreachable("expected scalar or aggregate expression");
523 case TEK_Scalar:
524 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
525 break;
526 case TEK_Aggregate: {
527 EmitAggExpr(E, AggValueSlot::forAddr(Object,
528 E->getType().getQualifiers(),
529 AggValueSlot::IsDestructed,
530 AggValueSlot::DoesNotNeedGCBarriers,
531 AggValueSlot::IsNotAliased,
532 AggValueSlot::DoesNotOverlap));
533 break;
534 }
535 }
536
537 pushTemporaryCleanup(*this, M, E, Object);
538 return RefTempDst;
539 }
540
541 SmallVector<const Expr *, 2> CommaLHSs;
542 SmallVector<SubobjectAdjustment, 2> Adjustments;
543 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
544
545 for (const auto &Ignored : CommaLHSs)
546 EmitIgnoredExpr(Ignored);
547
548 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
549 if (opaque->getType()->isRecordType()) {
550 assert(Adjustments.empty());
551 return EmitOpaqueValueLValue(opaque);
552 }
553 }
554
555 // Create and initialize the reference temporary.
556 RawAddress Alloca = Address::invalid();
557 RawAddress Object = createReferenceTemporary(*this, M, E, &Alloca);
558 if (auto *Var = dyn_cast<llvm::GlobalVariable>(
559 Object.getPointer()->stripPointerCasts())) {
560 llvm::Type *TemporaryType = ConvertTypeForMem(E->getType());
561 Object = Object.withElementType(TemporaryType);
562 // If the temporary is a global and has a constant initializer or is a
563 // constant temporary that we promoted to a global, we may have already
564 // initialized it.
565 if (!Var->hasInitializer()) {
566 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
567 QualType RefType = M->getType().withoutLocalFastQualifiers();
568 if (RefType.getPointerAuth()) {
569 // Use the qualifier of the reference temporary to sign the pointer.
570 LValue LV = MakeRawAddrLValue(Object.getPointer(), RefType,
571 Object.getAlignment());
572 EmitScalarInit(E, M->getExtendingDecl(), LV, false);
573 } else {
574 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/ true);
575 }
576 }
577 } else {
578 switch (M->getStorageDuration()) {
579 case SD_Automatic:
580 if (auto *Size = EmitLifetimeStart(
581 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
582 Alloca.getPointer())) {
583 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
584 Alloca, Size);
585 }
586 break;
587
588 case SD_FullExpression: {
589 if (!ShouldEmitLifetimeMarkers)
590 break;
591
592 // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
593 // marker. Instead, start the lifetime of a conditional temporary earlier
594 // so that it's unconditional. Don't do this with sanitizers which need
595 // more precise lifetime marks. However when inside an "await.suspend"
596 // block, we should always avoid conditional cleanup because it creates
597 // boolean marker that lives across await_suspend, which can destroy coro
598 // frame.
599 ConditionalEvaluation *OldConditional = nullptr;
600 CGBuilderTy::InsertPoint OldIP;
601 if (isInConditionalBranch() && !E->getType().isDestructedType() &&
602 ((!SanOpts.has(SanitizerKind::HWAddress) &&
603 !SanOpts.has(SanitizerKind::Memory) &&
604 !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) ||
605 inSuspendBlock())) {
606 OldConditional = OutermostConditional;
607 OutermostConditional = nullptr;
608
609 OldIP = Builder.saveIP();
610 llvm::BasicBlock *Block = OldConditional->getStartingBlock();
611 Builder.restoreIP(CGBuilderTy::InsertPoint(
612 Block, llvm::BasicBlock::iterator(Block->back())));
613 }
614
615 if (auto *Size = EmitLifetimeStart(
616 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
617 Alloca.getPointer())) {
618 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
619 Size);
620 }
621
622 if (OldConditional) {
623 OutermostConditional = OldConditional;
624 Builder.restoreIP(OldIP);
625 }
626 break;
627 }
628
629 default:
630 break;
631 }
632 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
633 }
634 pushTemporaryCleanup(*this, M, E, Object);
635
636 // Perform derived-to-base casts and/or field accesses, to get from the
637 // temporary object we created (and, potentially, for which we extended
638 // the lifetime) to the subobject we're binding the reference to.
639 for (SubobjectAdjustment &Adjustment : llvm::reverse(Adjustments)) {
640 switch (Adjustment.Kind) {
641 case SubobjectAdjustment::DerivedToBaseAdjustment:
642 Object =
643 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
644 Adjustment.DerivedToBase.BasePath->path_begin(),
645 Adjustment.DerivedToBase.BasePath->path_end(),
646 /*NullCheckValue=*/ false, E->getExprLoc());
647 break;
648
649 case SubobjectAdjustment::FieldAdjustment: {
650 LValue LV = MakeAddrLValue(Object, E->getType(), AlignmentSource::Decl);
651 LV = EmitLValueForField(LV, Adjustment.Field);
652 assert(LV.isSimple() &&
653 "materialized temporary field is not a simple lvalue");
654 Object = LV.getAddress();
655 break;
656 }
657
658 case SubobjectAdjustment::MemberPointerAdjustment: {
659 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
660 Object = EmitCXXMemberDataPointerAddress(
661 E, Object, Ptr, Adjustment.Ptr.MPT, /*IsInBounds=*/true);
662 break;
663 }
664 }
665 }
666
667 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
668 }
669
670 RValue
EmitReferenceBindingToExpr(const Expr * E)671 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
672 // Emit the expression as an lvalue.
673 LValue LV = EmitLValue(E);
674 assert(LV.isSimple());
675 llvm::Value *Value = LV.getPointer(*this);
676
677 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
678 // C++11 [dcl.ref]p5 (as amended by core issue 453):
679 // If a glvalue to which a reference is directly bound designates neither
680 // an existing object or function of an appropriate type nor a region of
681 // storage of suitable size and alignment to contain an object of the
682 // reference's type, the behavior is undefined.
683 QualType Ty = E->getType();
684 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
685 }
686
687 return RValue::get(Value);
688 }
689
690
691 /// getAccessedFieldNo - Given an encoded value and a result number, return the
692 /// input field number being accessed.
getAccessedFieldNo(unsigned Idx,const llvm::Constant * Elts)693 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
694 const llvm::Constant *Elts) {
695 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
696 ->getZExtValue();
697 }
698
emitHashMix(CGBuilderTy & Builder,llvm::Value * Acc,llvm::Value * Ptr)699 static llvm::Value *emitHashMix(CGBuilderTy &Builder, llvm::Value *Acc,
700 llvm::Value *Ptr) {
701 llvm::Value *A0 =
702 Builder.CreateMul(Ptr, Builder.getInt64(0xbf58476d1ce4e5b9u));
703 llvm::Value *A1 =
704 Builder.CreateXor(A0, Builder.CreateLShr(A0, Builder.getInt64(31)));
705 return Builder.CreateXor(Acc, A1);
706 }
707
isNullPointerAllowed(TypeCheckKind TCK)708 bool CodeGenFunction::isNullPointerAllowed(TypeCheckKind TCK) {
709 return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
710 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation;
711 }
712
isVptrCheckRequired(TypeCheckKind TCK,QualType Ty)713 bool CodeGenFunction::isVptrCheckRequired(TypeCheckKind TCK, QualType Ty) {
714 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
715 return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
716 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
717 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
718 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation);
719 }
720
sanitizePerformTypeCheck() const721 bool CodeGenFunction::sanitizePerformTypeCheck() const {
722 return SanOpts.has(SanitizerKind::Null) ||
723 SanOpts.has(SanitizerKind::Alignment) ||
724 SanOpts.has(SanitizerKind::ObjectSize) ||
725 SanOpts.has(SanitizerKind::Vptr);
726 }
727
EmitTypeCheck(TypeCheckKind TCK,SourceLocation Loc,llvm::Value * Ptr,QualType Ty,CharUnits Alignment,SanitizerSet SkippedChecks,llvm::Value * ArraySize)728 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
729 llvm::Value *Ptr, QualType Ty,
730 CharUnits Alignment,
731 SanitizerSet SkippedChecks,
732 llvm::Value *ArraySize) {
733 if (!sanitizePerformTypeCheck())
734 return;
735
736 // Don't check pointers outside the default address space. The null check
737 // isn't correct, the object-size check isn't supported by LLVM, and we can't
738 // communicate the addresses to the runtime handler for the vptr check.
739 if (Ptr->getType()->getPointerAddressSpace())
740 return;
741
742 // Don't check pointers to volatile data. The behavior here is implementation-
743 // defined.
744 if (Ty.isVolatileQualified())
745 return;
746
747 // Quickly determine whether we have a pointer to an alloca. It's possible
748 // to skip null checks, and some alignment checks, for these pointers. This
749 // can reduce compile-time significantly.
750 auto PtrToAlloca = dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCasts());
751
752 llvm::Value *IsNonNull = nullptr;
753 bool IsGuaranteedNonNull =
754 SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
755
756 llvm::BasicBlock *Done = nullptr;
757 bool DoneViaNullSanitize = false;
758
759 {
760 auto CheckHandler = SanitizerHandler::TypeMismatch;
761 SanitizerDebugLocation SanScope(this,
762 {SanitizerKind::SO_Null,
763 SanitizerKind::SO_ObjectSize,
764 SanitizerKind::SO_Alignment},
765 CheckHandler);
766
767 SmallVector<std::pair<llvm::Value *, SanitizerKind::SanitizerOrdinal>, 3>
768 Checks;
769
770 llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
771 bool AllowNullPointers = isNullPointerAllowed(TCK);
772 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
773 !IsGuaranteedNonNull) {
774 // The glvalue must not be an empty glvalue.
775 IsNonNull = Builder.CreateIsNotNull(Ptr);
776
777 // The IR builder can constant-fold the null check if the pointer points
778 // to a constant.
779 IsGuaranteedNonNull = IsNonNull == True;
780
781 // Skip the null check if the pointer is known to be non-null.
782 if (!IsGuaranteedNonNull) {
783 if (AllowNullPointers) {
784 // When performing pointer casts, it's OK if the value is null.
785 // Skip the remaining checks in that case.
786 Done = createBasicBlock("null");
787 DoneViaNullSanitize = true;
788 llvm::BasicBlock *Rest = createBasicBlock("not.null");
789 Builder.CreateCondBr(IsNonNull, Rest, Done);
790 EmitBlock(Rest);
791 } else {
792 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::SO_Null));
793 }
794 }
795 }
796
797 if (SanOpts.has(SanitizerKind::ObjectSize) &&
798 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
799 !Ty->isIncompleteType()) {
800 uint64_t TySize = CGM.getMinimumObjectSize(Ty).getQuantity();
801 llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
802 if (ArraySize)
803 Size = Builder.CreateMul(Size, ArraySize);
804
805 // Degenerate case: new X[0] does not need an objectsize check.
806 llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
807 if (!ConstantSize || !ConstantSize->isNullValue()) {
808 // The glvalue must refer to a large enough storage region.
809 // FIXME: If Address Sanitizer is enabled, insert dynamic
810 // instrumentation
811 // to check this.
812 // FIXME: Get object address space
813 llvm::Type *Tys[2] = {IntPtrTy, Int8PtrTy};
814 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
815 llvm::Value *Min = Builder.getFalse();
816 llvm::Value *NullIsUnknown = Builder.getFalse();
817 llvm::Value *Dynamic = Builder.getFalse();
818 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
819 Builder.CreateCall(F, {Ptr, Min, NullIsUnknown, Dynamic}), Size);
820 Checks.push_back(
821 std::make_pair(LargeEnough, SanitizerKind::SO_ObjectSize));
822 }
823 }
824
825 llvm::MaybeAlign AlignVal;
826 llvm::Value *PtrAsInt = nullptr;
827
828 if (SanOpts.has(SanitizerKind::Alignment) &&
829 !SkippedChecks.has(SanitizerKind::Alignment)) {
830 AlignVal = Alignment.getAsMaybeAlign();
831 if (!Ty->isIncompleteType() && !AlignVal)
832 AlignVal = CGM.getNaturalTypeAlignment(Ty, nullptr, nullptr,
833 /*ForPointeeType=*/true)
834 .getAsMaybeAlign();
835
836 // The glvalue must be suitably aligned.
837 if (AlignVal && *AlignVal > llvm::Align(1) &&
838 (!PtrToAlloca || PtrToAlloca->getAlign() < *AlignVal)) {
839 PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
840 llvm::Value *Align = Builder.CreateAnd(
841 PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal->value() - 1));
842 llvm::Value *Aligned =
843 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
844 if (Aligned != True)
845 Checks.push_back(
846 std::make_pair(Aligned, SanitizerKind::SO_Alignment));
847 }
848 }
849
850 if (Checks.size() > 0) {
851 llvm::Constant *StaticData[] = {
852 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
853 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2(*AlignVal) : 1),
854 llvm::ConstantInt::get(Int8Ty, TCK)};
855 EmitCheck(Checks, CheckHandler, StaticData, PtrAsInt ? PtrAsInt : Ptr);
856 }
857 }
858
859 // If possible, check that the vptr indicates that there is a subobject of
860 // type Ty at offset zero within this object.
861 //
862 // C++11 [basic.life]p5,6:
863 // [For storage which does not refer to an object within its lifetime]
864 // The program has undefined behavior if:
865 // -- the [pointer or glvalue] is used to access a non-static data member
866 // or call a non-static member function
867 if (SanOpts.has(SanitizerKind::Vptr) &&
868 !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
869 SanitizerDebugLocation SanScope(this, {SanitizerKind::SO_Vptr},
870 SanitizerHandler::DynamicTypeCacheMiss);
871
872 // Ensure that the pointer is non-null before loading it. If there is no
873 // compile-time guarantee, reuse the run-time null check or emit a new one.
874 if (!IsGuaranteedNonNull) {
875 if (!IsNonNull)
876 IsNonNull = Builder.CreateIsNotNull(Ptr);
877 if (!Done)
878 Done = createBasicBlock("vptr.null");
879 llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
880 Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
881 EmitBlock(VptrNotNull);
882 }
883
884 // Compute a deterministic hash of the mangled name of the type.
885 SmallString<64> MangledName;
886 llvm::raw_svector_ostream Out(MangledName);
887 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
888 Out);
889
890 // Contained in NoSanitizeList based on the mangled type.
891 if (!CGM.getContext().getNoSanitizeList().containsType(SanitizerKind::Vptr,
892 Out.str())) {
893 // Load the vptr, and mix it with TypeHash.
894 llvm::Value *TypeHash =
895 llvm::ConstantInt::get(Int64Ty, xxh3_64bits(Out.str()));
896
897 llvm::Type *VPtrTy = llvm::PointerType::get(getLLVMContext(), 0);
898 Address VPtrAddr(Ptr, IntPtrTy, getPointerAlign());
899 llvm::Value *VPtrVal = GetVTablePtr(VPtrAddr, VPtrTy,
900 Ty->getAsCXXRecordDecl(),
901 VTableAuthMode::UnsafeUbsanStrip);
902 VPtrVal = Builder.CreateBitOrPointerCast(VPtrVal, IntPtrTy);
903
904 llvm::Value *Hash =
905 emitHashMix(Builder, TypeHash, Builder.CreateZExt(VPtrVal, Int64Ty));
906 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
907
908 // Look the hash up in our cache.
909 const int CacheSize = 128;
910 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
911 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
912 "__ubsan_vptr_type_cache");
913 llvm::Value *Slot = Builder.CreateAnd(Hash,
914 llvm::ConstantInt::get(IntPtrTy,
915 CacheSize-1));
916 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
917 llvm::Value *CacheVal = Builder.CreateAlignedLoad(
918 IntPtrTy, Builder.CreateInBoundsGEP(HashTable, Cache, Indices),
919 getPointerAlign());
920
921 // If the hash isn't in the cache, call a runtime handler to perform the
922 // hard work of checking whether the vptr is for an object of the right
923 // type. This will either fill in the cache and return, or produce a
924 // diagnostic.
925 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
926 llvm::Constant *StaticData[] = {
927 EmitCheckSourceLocation(Loc),
928 EmitCheckTypeDescriptor(Ty),
929 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
930 llvm::ConstantInt::get(Int8Ty, TCK)
931 };
932 llvm::Value *DynamicData[] = { Ptr, Hash };
933 EmitCheck(std::make_pair(EqualHash, SanitizerKind::SO_Vptr),
934 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
935 DynamicData);
936 }
937 }
938
939 if (Done) {
940 SanitizerDebugLocation SanScope(
941 this,
942 {DoneViaNullSanitize ? SanitizerKind::SO_Null : SanitizerKind::SO_Vptr},
943 DoneViaNullSanitize ? SanitizerHandler::TypeMismatch
944 : SanitizerHandler::DynamicTypeCacheMiss);
945 Builder.CreateBr(Done);
946 EmitBlock(Done);
947 }
948 }
949
LoadPassedObjectSize(const Expr * E,QualType EltTy)950 llvm::Value *CodeGenFunction::LoadPassedObjectSize(const Expr *E,
951 QualType EltTy) {
952 ASTContext &C = getContext();
953 uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
954 if (!EltSize)
955 return nullptr;
956
957 auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
958 if (!ArrayDeclRef)
959 return nullptr;
960
961 auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
962 if (!ParamDecl)
963 return nullptr;
964
965 auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
966 if (!POSAttr)
967 return nullptr;
968
969 // Don't load the size if it's a lower bound.
970 int POSType = POSAttr->getType();
971 if (POSType != 0 && POSType != 1)
972 return nullptr;
973
974 // Find the implicit size parameter.
975 auto PassedSizeIt = SizeArguments.find(ParamDecl);
976 if (PassedSizeIt == SizeArguments.end())
977 return nullptr;
978
979 const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
980 assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
981 Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
982 llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
983 C.getSizeType(), E->getExprLoc());
984 llvm::Value *SizeOfElement =
985 llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
986 return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
987 }
988
989 /// If Base is known to point to the start of an array, return the length of
990 /// that array. Return 0 if the length cannot be determined.
getArrayIndexingBound(CodeGenFunction & CGF,const Expr * Base,QualType & IndexedType,LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel)991 static llvm::Value *getArrayIndexingBound(CodeGenFunction &CGF,
992 const Expr *Base,
993 QualType &IndexedType,
994 LangOptions::StrictFlexArraysLevelKind
995 StrictFlexArraysLevel) {
996 // For the vector indexing extension, the bound is the number of elements.
997 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
998 IndexedType = Base->getType();
999 return CGF.Builder.getInt32(VT->getNumElements());
1000 }
1001
1002 Base = Base->IgnoreParens();
1003
1004 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1005 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
1006 !CE->getSubExpr()->isFlexibleArrayMemberLike(CGF.getContext(),
1007 StrictFlexArraysLevel)) {
1008 CodeGenFunction::SanitizerScope SanScope(&CGF);
1009
1010 IndexedType = CE->getSubExpr()->getType();
1011 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
1012 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
1013 return CGF.Builder.getInt(CAT->getSize());
1014
1015 if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
1016 return CGF.getVLASize(VAT).NumElts;
1017 // Ignore pass_object_size here. It's not applicable on decayed pointers.
1018 }
1019 }
1020
1021 CodeGenFunction::SanitizerScope SanScope(&CGF);
1022
1023 QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
1024 if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
1025 IndexedType = Base->getType();
1026 return POS;
1027 }
1028
1029 return nullptr;
1030 }
1031
1032 namespace {
1033
1034 /// \p StructAccessBase returns the base \p Expr of a field access. It returns
1035 /// either a \p DeclRefExpr, representing the base pointer to the struct, i.e.:
1036 ///
1037 /// p in p-> a.b.c
1038 ///
1039 /// or a \p MemberExpr, if the \p MemberExpr has the \p RecordDecl we're
1040 /// looking for:
1041 ///
1042 /// struct s {
1043 /// struct s *ptr;
1044 /// int count;
1045 /// char array[] __attribute__((counted_by(count)));
1046 /// };
1047 ///
1048 /// If we have an expression like \p p->ptr->array[index], we want the
1049 /// \p MemberExpr for \p p->ptr instead of \p p.
1050 class StructAccessBase
1051 : public ConstStmtVisitor<StructAccessBase, const Expr *> {
1052 const RecordDecl *ExpectedRD;
1053
IsExpectedRecordDecl(const Expr * E) const1054 bool IsExpectedRecordDecl(const Expr *E) const {
1055 QualType Ty = E->getType();
1056 if (Ty->isPointerType())
1057 Ty = Ty->getPointeeType();
1058 return ExpectedRD == Ty->getAsRecordDecl();
1059 }
1060
1061 public:
StructAccessBase(const RecordDecl * ExpectedRD)1062 StructAccessBase(const RecordDecl *ExpectedRD) : ExpectedRD(ExpectedRD) {}
1063
1064 //===--------------------------------------------------------------------===//
1065 // Visitor Methods
1066 //===--------------------------------------------------------------------===//
1067
1068 // NOTE: If we build C++ support for counted_by, then we'll have to handle
1069 // horrors like this:
1070 //
1071 // struct S {
1072 // int x, y;
1073 // int blah[] __attribute__((counted_by(x)));
1074 // } s;
1075 //
1076 // int foo(int index, int val) {
1077 // int (S::*IHatePMDs)[] = &S::blah;
1078 // (s.*IHatePMDs)[index] = val;
1079 // }
1080
Visit(const Expr * E)1081 const Expr *Visit(const Expr *E) {
1082 return ConstStmtVisitor<StructAccessBase, const Expr *>::Visit(E);
1083 }
1084
VisitStmt(const Stmt * S)1085 const Expr *VisitStmt(const Stmt *S) { return nullptr; }
1086
1087 // These are the types we expect to return (in order of most to least
1088 // likely):
1089 //
1090 // 1. DeclRefExpr - This is the expression for the base of the structure.
1091 // It's exactly what we want to build an access to the \p counted_by
1092 // field.
1093 // 2. MemberExpr - This is the expression that has the same \p RecordDecl
1094 // as the flexble array member's lexical enclosing \p RecordDecl. This
1095 // allows us to catch things like: "p->p->array"
1096 // 3. CompoundLiteralExpr - This is for people who create something
1097 // heretical like (struct foo has a flexible array member):
1098 //
1099 // (struct foo){ 1, 2 }.blah[idx];
VisitDeclRefExpr(const DeclRefExpr * E)1100 const Expr *VisitDeclRefExpr(const DeclRefExpr *E) {
1101 return IsExpectedRecordDecl(E) ? E : nullptr;
1102 }
VisitMemberExpr(const MemberExpr * E)1103 const Expr *VisitMemberExpr(const MemberExpr *E) {
1104 if (IsExpectedRecordDecl(E) && E->isArrow())
1105 return E;
1106 const Expr *Res = Visit(E->getBase());
1107 return !Res && IsExpectedRecordDecl(E) ? E : Res;
1108 }
VisitCompoundLiteralExpr(const CompoundLiteralExpr * E)1109 const Expr *VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1110 return IsExpectedRecordDecl(E) ? E : nullptr;
1111 }
VisitCallExpr(const CallExpr * E)1112 const Expr *VisitCallExpr(const CallExpr *E) {
1113 return IsExpectedRecordDecl(E) ? E : nullptr;
1114 }
1115
VisitArraySubscriptExpr(const ArraySubscriptExpr * E)1116 const Expr *VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1117 if (IsExpectedRecordDecl(E))
1118 return E;
1119 return Visit(E->getBase());
1120 }
VisitCastExpr(const CastExpr * E)1121 const Expr *VisitCastExpr(const CastExpr *E) {
1122 if (E->getCastKind() == CK_LValueToRValue)
1123 return IsExpectedRecordDecl(E) ? E : nullptr;
1124 return Visit(E->getSubExpr());
1125 }
VisitParenExpr(const ParenExpr * E)1126 const Expr *VisitParenExpr(const ParenExpr *E) {
1127 return Visit(E->getSubExpr());
1128 }
VisitUnaryAddrOf(const UnaryOperator * E)1129 const Expr *VisitUnaryAddrOf(const UnaryOperator *E) {
1130 return Visit(E->getSubExpr());
1131 }
VisitUnaryDeref(const UnaryOperator * E)1132 const Expr *VisitUnaryDeref(const UnaryOperator *E) {
1133 return Visit(E->getSubExpr());
1134 }
1135 };
1136
1137 } // end anonymous namespace
1138
1139 using RecIndicesTy = SmallVector<llvm::Value *, 8>;
1140
getGEPIndicesToField(CodeGenFunction & CGF,const RecordDecl * RD,const FieldDecl * Field,RecIndicesTy & Indices)1141 static bool getGEPIndicesToField(CodeGenFunction &CGF, const RecordDecl *RD,
1142 const FieldDecl *Field,
1143 RecIndicesTy &Indices) {
1144 const CGRecordLayout &Layout = CGF.CGM.getTypes().getCGRecordLayout(RD);
1145 int64_t FieldNo = -1;
1146 for (const FieldDecl *FD : RD->fields()) {
1147 if (!Layout.containsFieldDecl(FD))
1148 // This could happen if the field has a struct type that's empty. I don't
1149 // know why either.
1150 continue;
1151
1152 FieldNo = Layout.getLLVMFieldNo(FD);
1153 if (FD == Field) {
1154 Indices.emplace_back(CGF.Builder.getInt32(FieldNo));
1155 return true;
1156 }
1157
1158 QualType Ty = FD->getType();
1159 if (Ty->isRecordType()) {
1160 if (getGEPIndicesToField(CGF, Ty->getAsRecordDecl(), Field, Indices)) {
1161 if (RD->isUnion())
1162 FieldNo = 0;
1163 Indices.emplace_back(CGF.Builder.getInt32(FieldNo));
1164 return true;
1165 }
1166 }
1167 }
1168
1169 return false;
1170 }
1171
GetCountedByFieldExprGEP(const Expr * Base,const FieldDecl * FAMDecl,const FieldDecl * CountDecl)1172 llvm::Value *CodeGenFunction::GetCountedByFieldExprGEP(
1173 const Expr *Base, const FieldDecl *FAMDecl, const FieldDecl *CountDecl) {
1174 const RecordDecl *RD = CountDecl->getParent()->getOuterLexicalRecordContext();
1175
1176 // Find the base struct expr (i.e. p in p->a.b.c.d).
1177 const Expr *StructBase = StructAccessBase(RD).Visit(Base);
1178 if (!StructBase || StructBase->HasSideEffects(getContext()))
1179 return nullptr;
1180
1181 llvm::Value *Res = nullptr;
1182 if (StructBase->getType()->isPointerType()) {
1183 LValueBaseInfo BaseInfo;
1184 TBAAAccessInfo TBAAInfo;
1185 Address Addr = EmitPointerWithAlignment(StructBase, &BaseInfo, &TBAAInfo);
1186 Res = Addr.emitRawPointer(*this);
1187 } else if (StructBase->isLValue()) {
1188 LValue LV = EmitLValue(StructBase);
1189 Address Addr = LV.getAddress();
1190 Res = Addr.emitRawPointer(*this);
1191 } else {
1192 return nullptr;
1193 }
1194
1195 RecIndicesTy Indices;
1196 getGEPIndicesToField(*this, RD, CountDecl, Indices);
1197 if (Indices.empty())
1198 return nullptr;
1199
1200 Indices.push_back(Builder.getInt32(0));
1201 return Builder.CreateInBoundsGEP(
1202 ConvertType(QualType(RD->getTypeForDecl(), 0)), Res,
1203 RecIndicesTy(llvm::reverse(Indices)), "counted_by.gep");
1204 }
1205
1206 /// This method is typically called in contexts where we can't generate
1207 /// side-effects, like in __builtin_dynamic_object_size. When finding
1208 /// expressions, only choose those that have either already been emitted or can
1209 /// be loaded without side-effects.
1210 ///
1211 /// - \p FAMDecl: the \p Decl for the flexible array member. It may not be
1212 /// within the top-level struct.
1213 /// - \p CountDecl: must be within the same non-anonymous struct as \p FAMDecl.
EmitLoadOfCountedByField(const Expr * Base,const FieldDecl * FAMDecl,const FieldDecl * CountDecl)1214 llvm::Value *CodeGenFunction::EmitLoadOfCountedByField(
1215 const Expr *Base, const FieldDecl *FAMDecl, const FieldDecl *CountDecl) {
1216 if (llvm::Value *GEP = GetCountedByFieldExprGEP(Base, FAMDecl, CountDecl))
1217 return Builder.CreateAlignedLoad(ConvertType(CountDecl->getType()), GEP,
1218 getIntAlign(), "counted_by.load");
1219 return nullptr;
1220 }
1221
EmitBoundsCheck(const Expr * E,const Expr * Base,llvm::Value * Index,QualType IndexType,bool Accessed)1222 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
1223 llvm::Value *Index, QualType IndexType,
1224 bool Accessed) {
1225 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
1226 "should not be called unless adding bounds checks");
1227 const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
1228 getLangOpts().getStrictFlexArraysLevel();
1229 QualType IndexedType;
1230 llvm::Value *Bound =
1231 getArrayIndexingBound(*this, Base, IndexedType, StrictFlexArraysLevel);
1232
1233 EmitBoundsCheckImpl(E, Bound, Index, IndexType, IndexedType, Accessed);
1234 }
1235
EmitBoundsCheckImpl(const Expr * E,llvm::Value * Bound,llvm::Value * Index,QualType IndexType,QualType IndexedType,bool Accessed)1236 void CodeGenFunction::EmitBoundsCheckImpl(const Expr *E, llvm::Value *Bound,
1237 llvm::Value *Index,
1238 QualType IndexType,
1239 QualType IndexedType, bool Accessed) {
1240 if (!Bound)
1241 return;
1242
1243 auto CheckKind = SanitizerKind::SO_ArrayBounds;
1244 auto CheckHandler = SanitizerHandler::OutOfBounds;
1245 SanitizerDebugLocation SanScope(this, {CheckKind}, CheckHandler);
1246
1247 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
1248 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
1249 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
1250
1251 llvm::Constant *StaticData[] = {
1252 EmitCheckSourceLocation(E->getExprLoc()),
1253 EmitCheckTypeDescriptor(IndexedType),
1254 EmitCheckTypeDescriptor(IndexType)
1255 };
1256 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
1257 : Builder.CreateICmpULE(IndexVal, BoundVal);
1258 EmitCheck(std::make_pair(Check, CheckKind), CheckHandler, StaticData, Index);
1259 }
1260
1261 CodeGenFunction::ComplexPairTy CodeGenFunction::
EmitComplexPrePostIncDec(const UnaryOperator * E,LValue LV,bool isInc,bool isPre)1262 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
1263 bool isInc, bool isPre) {
1264 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
1265
1266 llvm::Value *NextVal;
1267 if (isa<llvm::IntegerType>(InVal.first->getType())) {
1268 uint64_t AmountVal = isInc ? 1 : -1;
1269 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
1270
1271 // Add the inc/dec to the real part.
1272 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1273 } else {
1274 QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
1275 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1276 if (!isInc)
1277 FVal.changeSign();
1278 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1279
1280 // Add the inc/dec to the real part.
1281 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1282 }
1283
1284 ComplexPairTy IncVal(NextVal, InVal.second);
1285
1286 // Store the updated result through the lvalue.
1287 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1288 if (getLangOpts().OpenMP)
1289 CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this,
1290 E->getSubExpr());
1291
1292 // If this is a postinc, return the value read from memory, otherwise use the
1293 // updated value.
1294 return isPre ? IncVal : InVal;
1295 }
1296
EmitExplicitCastExprType(const ExplicitCastExpr * E,CodeGenFunction * CGF)1297 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
1298 CodeGenFunction *CGF) {
1299 // Bind VLAs in the cast type.
1300 if (CGF && E->getType()->isVariablyModifiedType())
1301 CGF->EmitVariablyModifiedType(E->getType());
1302
1303 if (CGDebugInfo *DI = getModuleDebugInfo())
1304 DI->EmitExplicitCastType(E->getType());
1305 }
1306
1307 //===----------------------------------------------------------------------===//
1308 // LValue Expression Emission
1309 //===----------------------------------------------------------------------===//
1310
EmitPointerWithAlignment(const Expr * E,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo,KnownNonNull_t IsKnownNonNull,CodeGenFunction & CGF)1311 static Address EmitPointerWithAlignment(const Expr *E, LValueBaseInfo *BaseInfo,
1312 TBAAAccessInfo *TBAAInfo,
1313 KnownNonNull_t IsKnownNonNull,
1314 CodeGenFunction &CGF) {
1315 // We allow this with ObjC object pointers because of fragile ABIs.
1316 assert(E->getType()->isPointerType() ||
1317 E->getType()->isObjCObjectPointerType());
1318 E = E->IgnoreParens();
1319
1320 // Casts:
1321 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1322 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1323 CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
1324
1325 switch (CE->getCastKind()) {
1326 // Non-converting casts (but not C's implicit conversion from void*).
1327 case CK_BitCast:
1328 case CK_NoOp:
1329 case CK_AddressSpaceConversion:
1330 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1331 if (PtrTy->getPointeeType()->isVoidType())
1332 break;
1333
1334 LValueBaseInfo InnerBaseInfo;
1335 TBAAAccessInfo InnerTBAAInfo;
1336 Address Addr = CGF.EmitPointerWithAlignment(
1337 CE->getSubExpr(), &InnerBaseInfo, &InnerTBAAInfo, IsKnownNonNull);
1338 if (BaseInfo) *BaseInfo = InnerBaseInfo;
1339 if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1340
1341 if (isa<ExplicitCastExpr>(CE)) {
1342 LValueBaseInfo TargetTypeBaseInfo;
1343 TBAAAccessInfo TargetTypeTBAAInfo;
1344 CharUnits Align = CGF.CGM.getNaturalPointeeTypeAlignment(
1345 E->getType(), &TargetTypeBaseInfo, &TargetTypeTBAAInfo);
1346 if (TBAAInfo)
1347 *TBAAInfo =
1348 CGF.CGM.mergeTBAAInfoForCast(*TBAAInfo, TargetTypeTBAAInfo);
1349 // If the source l-value is opaque, honor the alignment of the
1350 // casted-to type.
1351 if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1352 if (BaseInfo)
1353 BaseInfo->mergeForCast(TargetTypeBaseInfo);
1354 Addr.setAlignment(Align);
1355 }
1356 }
1357
1358 if (CGF.SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1359 CE->getCastKind() == CK_BitCast) {
1360 if (auto PT = E->getType()->getAs<PointerType>())
1361 CGF.EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr,
1362 /*MayBeNull=*/true,
1363 CodeGenFunction::CFITCK_UnrelatedCast,
1364 CE->getBeginLoc());
1365 }
1366
1367 llvm::Type *ElemTy =
1368 CGF.ConvertTypeForMem(E->getType()->getPointeeType());
1369 Addr = Addr.withElementType(ElemTy);
1370 if (CE->getCastKind() == CK_AddressSpaceConversion)
1371 Addr = CGF.Builder.CreateAddrSpaceCast(
1372 Addr, CGF.ConvertType(E->getType()), ElemTy);
1373 return CGF.authPointerToPointerCast(Addr, CE->getSubExpr()->getType(),
1374 CE->getType());
1375 }
1376 break;
1377
1378 // Array-to-pointer decay.
1379 case CK_ArrayToPointerDecay:
1380 return CGF.EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1381
1382 // Derived-to-base conversions.
1383 case CK_UncheckedDerivedToBase:
1384 case CK_DerivedToBase: {
1385 // TODO: Support accesses to members of base classes in TBAA. For now, we
1386 // conservatively pretend that the complete object is of the base class
1387 // type.
1388 if (TBAAInfo)
1389 *TBAAInfo = CGF.CGM.getTBAAAccessInfo(E->getType());
1390 Address Addr = CGF.EmitPointerWithAlignment(
1391 CE->getSubExpr(), BaseInfo, nullptr,
1392 (KnownNonNull_t)(IsKnownNonNull ||
1393 CE->getCastKind() == CK_UncheckedDerivedToBase));
1394 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1395 return CGF.GetAddressOfBaseClass(
1396 Addr, Derived, CE->path_begin(), CE->path_end(),
1397 CGF.ShouldNullCheckClassCastValue(CE), CE->getExprLoc());
1398 }
1399
1400 // TODO: Is there any reason to treat base-to-derived conversions
1401 // specially?
1402 default:
1403 break;
1404 }
1405 }
1406
1407 // Unary &.
1408 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1409 if (UO->getOpcode() == UO_AddrOf) {
1410 LValue LV = CGF.EmitLValue(UO->getSubExpr(), IsKnownNonNull);
1411 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1412 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1413 return LV.getAddress();
1414 }
1415 }
1416
1417 // std::addressof and variants.
1418 if (auto *Call = dyn_cast<CallExpr>(E)) {
1419 switch (Call->getBuiltinCallee()) {
1420 default:
1421 break;
1422 case Builtin::BIaddressof:
1423 case Builtin::BI__addressof:
1424 case Builtin::BI__builtin_addressof: {
1425 LValue LV = CGF.EmitLValue(Call->getArg(0), IsKnownNonNull);
1426 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1427 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1428 return LV.getAddress();
1429 }
1430 }
1431 }
1432
1433 // TODO: conditional operators, comma.
1434
1435 // Otherwise, use the alignment of the type.
1436 return CGF.makeNaturalAddressForPointer(
1437 CGF.EmitScalarExpr(E), E->getType()->getPointeeType(), CharUnits(),
1438 /*ForPointeeType=*/true, BaseInfo, TBAAInfo, IsKnownNonNull);
1439 }
1440
1441 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1442 /// derive a more accurate bound on the alignment of the pointer.
EmitPointerWithAlignment(const Expr * E,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo,KnownNonNull_t IsKnownNonNull)1443 Address CodeGenFunction::EmitPointerWithAlignment(
1444 const Expr *E, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo,
1445 KnownNonNull_t IsKnownNonNull) {
1446 Address Addr =
1447 ::EmitPointerWithAlignment(E, BaseInfo, TBAAInfo, IsKnownNonNull, *this);
1448 if (IsKnownNonNull && !Addr.isKnownNonNull())
1449 Addr.setKnownNonNull();
1450 return Addr;
1451 }
1452
EmitNonNullRValueCheck(RValue RV,QualType T)1453 llvm::Value *CodeGenFunction::EmitNonNullRValueCheck(RValue RV, QualType T) {
1454 llvm::Value *V = RV.getScalarVal();
1455 if (auto MPT = T->getAs<MemberPointerType>())
1456 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, V, MPT);
1457 return Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType()));
1458 }
1459
GetUndefRValue(QualType Ty)1460 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
1461 if (Ty->isVoidType())
1462 return RValue::get(nullptr);
1463
1464 switch (getEvaluationKind(Ty)) {
1465 case TEK_Complex: {
1466 llvm::Type *EltTy =
1467 ConvertType(Ty->castAs<ComplexType>()->getElementType());
1468 llvm::Value *U = llvm::UndefValue::get(EltTy);
1469 return RValue::getComplex(std::make_pair(U, U));
1470 }
1471
1472 // If this is a use of an undefined aggregate type, the aggregate must have an
1473 // identifiable address. Just because the contents of the value are undefined
1474 // doesn't mean that the address can't be taken and compared.
1475 case TEK_Aggregate: {
1476 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1477 return RValue::getAggregate(DestPtr);
1478 }
1479
1480 case TEK_Scalar:
1481 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1482 }
1483 llvm_unreachable("bad evaluation kind");
1484 }
1485
EmitUnsupportedRValue(const Expr * E,const char * Name)1486 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
1487 const char *Name) {
1488 ErrorUnsupported(E, Name);
1489 return GetUndefRValue(E->getType());
1490 }
1491
EmitUnsupportedLValue(const Expr * E,const char * Name)1492 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
1493 const char *Name) {
1494 ErrorUnsupported(E, Name);
1495 llvm::Type *ElTy = ConvertType(E->getType());
1496 llvm::Type *Ty = UnqualPtrTy;
1497 return MakeAddrLValue(
1498 Address(llvm::UndefValue::get(Ty), ElTy, CharUnits::One()), E->getType());
1499 }
1500
IsWrappedCXXThis(const Expr * Obj)1501 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
1502 const Expr *Base = Obj;
1503 while (!isa<CXXThisExpr>(Base)) {
1504 // The result of a dynamic_cast can be null.
1505 if (isa<CXXDynamicCastExpr>(Base))
1506 return false;
1507
1508 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1509 Base = CE->getSubExpr();
1510 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1511 Base = PE->getSubExpr();
1512 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1513 if (UO->getOpcode() == UO_Extension)
1514 Base = UO->getSubExpr();
1515 else
1516 return false;
1517 } else {
1518 return false;
1519 }
1520 }
1521 return true;
1522 }
1523
EmitCheckedLValue(const Expr * E,TypeCheckKind TCK)1524 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1525 LValue LV;
1526 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1527 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1528 else
1529 LV = EmitLValue(E);
1530 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1531 SanitizerSet SkippedChecks;
1532 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1533 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1534 if (IsBaseCXXThis)
1535 SkippedChecks.set(SanitizerKind::Alignment, true);
1536 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1537 SkippedChecks.set(SanitizerKind::Null, true);
1538 }
1539 EmitTypeCheck(TCK, E->getExprLoc(), LV, E->getType(), SkippedChecks);
1540 }
1541 return LV;
1542 }
1543
1544 /// EmitLValue - Emit code to compute a designator that specifies the location
1545 /// of the expression.
1546 ///
1547 /// This can return one of two things: a simple address or a bitfield reference.
1548 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1549 /// an LLVM pointer type.
1550 ///
1551 /// If this returns a bitfield reference, nothing about the pointee type of the
1552 /// LLVM value is known: For example, it may not be a pointer to an integer.
1553 ///
1554 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1555 /// this method guarantees that the returned pointer type will point to an LLVM
1556 /// type of the same size of the lvalue's type. If the lvalue has a variable
1557 /// length type, this is not possible.
1558 ///
EmitLValue(const Expr * E,KnownNonNull_t IsKnownNonNull)1559 LValue CodeGenFunction::EmitLValue(const Expr *E,
1560 KnownNonNull_t IsKnownNonNull) {
1561 // Running with sufficient stack space to avoid deeply nested expressions
1562 // cause a stack overflow.
1563 LValue LV;
1564 CGM.runWithSufficientStackSpace(
1565 E->getExprLoc(), [&] { LV = EmitLValueHelper(E, IsKnownNonNull); });
1566
1567 if (IsKnownNonNull && !LV.isKnownNonNull())
1568 LV.setKnownNonNull();
1569 return LV;
1570 }
1571
getConstantExprReferredType(const FullExpr * E,const ASTContext & Ctx)1572 static QualType getConstantExprReferredType(const FullExpr *E,
1573 const ASTContext &Ctx) {
1574 const Expr *SE = E->getSubExpr()->IgnoreImplicit();
1575 if (isa<OpaqueValueExpr>(SE))
1576 return SE->getType();
1577 return cast<CallExpr>(SE)->getCallReturnType(Ctx)->getPointeeType();
1578 }
1579
EmitLValueHelper(const Expr * E,KnownNonNull_t IsKnownNonNull)1580 LValue CodeGenFunction::EmitLValueHelper(const Expr *E,
1581 KnownNonNull_t IsKnownNonNull) {
1582 ApplyDebugLocation DL(*this, E);
1583 switch (E->getStmtClass()) {
1584 default: return EmitUnsupportedLValue(E, "l-value expression");
1585
1586 case Expr::ObjCPropertyRefExprClass:
1587 llvm_unreachable("cannot emit a property reference directly");
1588
1589 case Expr::ObjCSelectorExprClass:
1590 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1591 case Expr::ObjCIsaExprClass:
1592 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1593 case Expr::BinaryOperatorClass:
1594 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1595 case Expr::CompoundAssignOperatorClass: {
1596 QualType Ty = E->getType();
1597 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1598 Ty = AT->getValueType();
1599 if (!Ty->isAnyComplexType())
1600 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1601 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1602 }
1603 case Expr::CallExprClass:
1604 case Expr::CXXMemberCallExprClass:
1605 case Expr::CXXOperatorCallExprClass:
1606 case Expr::UserDefinedLiteralClass:
1607 return EmitCallExprLValue(cast<CallExpr>(E));
1608 case Expr::CXXRewrittenBinaryOperatorClass:
1609 return EmitLValue(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm(),
1610 IsKnownNonNull);
1611 case Expr::VAArgExprClass:
1612 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1613 case Expr::DeclRefExprClass:
1614 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1615 case Expr::ConstantExprClass: {
1616 const ConstantExpr *CE = cast<ConstantExpr>(E);
1617 if (llvm::Value *Result = ConstantEmitter(*this).tryEmitConstantExpr(CE)) {
1618 QualType RetType = getConstantExprReferredType(CE, getContext());
1619 return MakeNaturalAlignAddrLValue(Result, RetType);
1620 }
1621 return EmitLValue(cast<ConstantExpr>(E)->getSubExpr(), IsKnownNonNull);
1622 }
1623 case Expr::ParenExprClass:
1624 return EmitLValue(cast<ParenExpr>(E)->getSubExpr(), IsKnownNonNull);
1625 case Expr::GenericSelectionExprClass:
1626 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr(),
1627 IsKnownNonNull);
1628 case Expr::PredefinedExprClass:
1629 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1630 case Expr::StringLiteralClass:
1631 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1632 case Expr::ObjCEncodeExprClass:
1633 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1634 case Expr::PseudoObjectExprClass:
1635 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1636 case Expr::InitListExprClass:
1637 return EmitInitListLValue(cast<InitListExpr>(E));
1638 case Expr::CXXTemporaryObjectExprClass:
1639 case Expr::CXXConstructExprClass:
1640 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1641 case Expr::CXXBindTemporaryExprClass:
1642 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1643 case Expr::CXXUuidofExprClass:
1644 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1645 case Expr::LambdaExprClass:
1646 return EmitAggExprToLValue(E);
1647
1648 case Expr::ExprWithCleanupsClass: {
1649 const auto *cleanups = cast<ExprWithCleanups>(E);
1650 RunCleanupsScope Scope(*this);
1651 LValue LV = EmitLValue(cleanups->getSubExpr(), IsKnownNonNull);
1652 if (LV.isSimple()) {
1653 // Defend against branches out of gnu statement expressions surrounded by
1654 // cleanups.
1655 Address Addr = LV.getAddress();
1656 llvm::Value *V = Addr.getBasePointer();
1657 Scope.ForceCleanup({&V});
1658 Addr.replaceBasePointer(V);
1659 return LValue::MakeAddr(Addr, LV.getType(), getContext(),
1660 LV.getBaseInfo(), LV.getTBAAInfo());
1661 }
1662 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1663 // bitfield lvalue or some other non-simple lvalue?
1664 return LV;
1665 }
1666
1667 case Expr::CXXDefaultArgExprClass: {
1668 auto *DAE = cast<CXXDefaultArgExpr>(E);
1669 CXXDefaultArgExprScope Scope(*this, DAE);
1670 return EmitLValue(DAE->getExpr(), IsKnownNonNull);
1671 }
1672 case Expr::CXXDefaultInitExprClass: {
1673 auto *DIE = cast<CXXDefaultInitExpr>(E);
1674 CXXDefaultInitExprScope Scope(*this, DIE);
1675 return EmitLValue(DIE->getExpr(), IsKnownNonNull);
1676 }
1677 case Expr::CXXTypeidExprClass:
1678 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1679
1680 case Expr::ObjCMessageExprClass:
1681 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1682 case Expr::ObjCIvarRefExprClass:
1683 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1684 case Expr::StmtExprClass:
1685 return EmitStmtExprLValue(cast<StmtExpr>(E));
1686 case Expr::UnaryOperatorClass:
1687 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1688 case Expr::ArraySubscriptExprClass:
1689 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1690 case Expr::MatrixSubscriptExprClass:
1691 return EmitMatrixSubscriptExpr(cast<MatrixSubscriptExpr>(E));
1692 case Expr::ArraySectionExprClass:
1693 return EmitArraySectionExpr(cast<ArraySectionExpr>(E));
1694 case Expr::ExtVectorElementExprClass:
1695 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1696 case Expr::CXXThisExprClass:
1697 return MakeAddrLValue(LoadCXXThisAddress(), E->getType());
1698 case Expr::MemberExprClass:
1699 return EmitMemberExpr(cast<MemberExpr>(E));
1700 case Expr::CompoundLiteralExprClass:
1701 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1702 case Expr::ConditionalOperatorClass:
1703 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1704 case Expr::BinaryConditionalOperatorClass:
1705 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1706 case Expr::ChooseExprClass:
1707 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(), IsKnownNonNull);
1708 case Expr::OpaqueValueExprClass:
1709 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1710 case Expr::SubstNonTypeTemplateParmExprClass:
1711 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(),
1712 IsKnownNonNull);
1713 case Expr::ImplicitCastExprClass:
1714 case Expr::CStyleCastExprClass:
1715 case Expr::CXXFunctionalCastExprClass:
1716 case Expr::CXXStaticCastExprClass:
1717 case Expr::CXXDynamicCastExprClass:
1718 case Expr::CXXReinterpretCastExprClass:
1719 case Expr::CXXConstCastExprClass:
1720 case Expr::CXXAddrspaceCastExprClass:
1721 case Expr::ObjCBridgedCastExprClass:
1722 return EmitCastLValue(cast<CastExpr>(E));
1723
1724 case Expr::MaterializeTemporaryExprClass:
1725 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1726
1727 case Expr::CoawaitExprClass:
1728 return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1729 case Expr::CoyieldExprClass:
1730 return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1731 case Expr::PackIndexingExprClass:
1732 return EmitLValue(cast<PackIndexingExpr>(E)->getSelectedExpr());
1733 case Expr::HLSLOutArgExprClass:
1734 llvm_unreachable("cannot emit a HLSL out argument directly");
1735 }
1736 }
1737
1738 /// Given an object of the given canonical type, can we safely copy a
1739 /// value out of it based on its initializer?
isConstantEmittableObjectType(QualType type)1740 static bool isConstantEmittableObjectType(QualType type) {
1741 assert(type.isCanonical());
1742 assert(!type->isReferenceType());
1743
1744 // Must be const-qualified but non-volatile.
1745 Qualifiers qs = type.getLocalQualifiers();
1746 if (!qs.hasConst() || qs.hasVolatile()) return false;
1747
1748 // Otherwise, all object types satisfy this except C++ classes with
1749 // mutable subobjects or non-trivial copy/destroy behavior.
1750 if (const auto *RT = dyn_cast<RecordType>(type))
1751 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1752 if (RD->hasMutableFields() || !RD->isTrivial())
1753 return false;
1754
1755 return true;
1756 }
1757
1758 /// Can we constant-emit a load of a reference to a variable of the
1759 /// given type? This is different from predicates like
1760 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1761 /// in situations that don't necessarily satisfy the language's rules
1762 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1763 /// to do this with const float variables even if those variables
1764 /// aren't marked 'constexpr'.
1765 enum ConstantEmissionKind {
1766 CEK_None,
1767 CEK_AsReferenceOnly,
1768 CEK_AsValueOrReference,
1769 CEK_AsValueOnly
1770 };
checkVarTypeForConstantEmission(QualType type)1771 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1772 type = type.getCanonicalType();
1773 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1774 if (isConstantEmittableObjectType(ref->getPointeeType()))
1775 return CEK_AsValueOrReference;
1776 return CEK_AsReferenceOnly;
1777 }
1778 if (isConstantEmittableObjectType(type))
1779 return CEK_AsValueOnly;
1780 return CEK_None;
1781 }
1782
1783 /// Try to emit a reference to the given value without producing it as
1784 /// an l-value. This is just an optimization, but it avoids us needing
1785 /// to emit global copies of variables if they're named without triggering
1786 /// a formal use in a context where we can't emit a direct reference to them,
1787 /// for instance if a block or lambda or a member of a local class uses a
1788 /// const int variable or constexpr variable from an enclosing function.
1789 CodeGenFunction::ConstantEmission
tryEmitAsConstant(const DeclRefExpr * RefExpr)1790 CodeGenFunction::tryEmitAsConstant(const DeclRefExpr *RefExpr) {
1791 const ValueDecl *Value = RefExpr->getDecl();
1792
1793 // The value needs to be an enum constant or a constant variable.
1794 ConstantEmissionKind CEK;
1795 if (isa<ParmVarDecl>(Value)) {
1796 CEK = CEK_None;
1797 } else if (const auto *var = dyn_cast<VarDecl>(Value)) {
1798 CEK = checkVarTypeForConstantEmission(var->getType());
1799 } else if (isa<EnumConstantDecl>(Value)) {
1800 CEK = CEK_AsValueOnly;
1801 } else {
1802 CEK = CEK_None;
1803 }
1804 if (CEK == CEK_None) return ConstantEmission();
1805
1806 Expr::EvalResult result;
1807 bool resultIsReference;
1808 QualType resultType;
1809
1810 // It's best to evaluate all the way as an r-value if that's permitted.
1811 if (CEK != CEK_AsReferenceOnly &&
1812 RefExpr->EvaluateAsRValue(result, getContext())) {
1813 resultIsReference = false;
1814 resultType = RefExpr->getType().getUnqualifiedType();
1815
1816 // Otherwise, try to evaluate as an l-value.
1817 } else if (CEK != CEK_AsValueOnly &&
1818 RefExpr->EvaluateAsLValue(result, getContext())) {
1819 resultIsReference = true;
1820 resultType = Value->getType();
1821
1822 // Failure.
1823 } else {
1824 return ConstantEmission();
1825 }
1826
1827 // In any case, if the initializer has side-effects, abandon ship.
1828 if (result.HasSideEffects)
1829 return ConstantEmission();
1830
1831 // In CUDA/HIP device compilation, a lambda may capture a reference variable
1832 // referencing a global host variable by copy. In this case the lambda should
1833 // make a copy of the value of the global host variable. The DRE of the
1834 // captured reference variable cannot be emitted as load from the host
1835 // global variable as compile time constant, since the host variable is not
1836 // accessible on device. The DRE of the captured reference variable has to be
1837 // loaded from captures.
1838 if (CGM.getLangOpts().CUDAIsDevice && result.Val.isLValue() &&
1839 RefExpr->refersToEnclosingVariableOrCapture()) {
1840 auto *MD = dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl);
1841 if (isLambdaMethod(MD) && MD->getOverloadedOperator() == OO_Call) {
1842 const APValue::LValueBase &base = result.Val.getLValueBase();
1843 if (const ValueDecl *D = base.dyn_cast<const ValueDecl *>()) {
1844 if (const VarDecl *VD = dyn_cast<const VarDecl>(D)) {
1845 if (!VD->hasAttr<CUDADeviceAttr>()) {
1846 return ConstantEmission();
1847 }
1848 }
1849 }
1850 }
1851 }
1852
1853 // Emit as a constant.
1854 llvm::Constant *C = ConstantEmitter(*this).emitAbstract(
1855 RefExpr->getLocation(), result.Val, resultType);
1856
1857 // Make sure we emit a debug reference to the global variable.
1858 // This should probably fire even for
1859 if (isa<VarDecl>(Value)) {
1860 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(Value)))
1861 EmitDeclRefExprDbgValue(RefExpr, result.Val);
1862 } else {
1863 assert(isa<EnumConstantDecl>(Value));
1864 EmitDeclRefExprDbgValue(RefExpr, result.Val);
1865 }
1866
1867 // If we emitted a reference constant, we need to dereference that.
1868 if (resultIsReference)
1869 return ConstantEmission::forReference(C);
1870
1871 return ConstantEmission::forValue(C);
1872 }
1873
tryToConvertMemberExprToDeclRefExpr(CodeGenFunction & CGF,const MemberExpr * ME)1874 static DeclRefExpr *tryToConvertMemberExprToDeclRefExpr(CodeGenFunction &CGF,
1875 const MemberExpr *ME) {
1876 if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1877 // Try to emit static variable member expressions as DREs.
1878 return DeclRefExpr::Create(
1879 CGF.getContext(), NestedNameSpecifierLoc(), SourceLocation(), VD,
1880 /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1881 ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1882 }
1883 return nullptr;
1884 }
1885
1886 CodeGenFunction::ConstantEmission
tryEmitAsConstant(const MemberExpr * ME)1887 CodeGenFunction::tryEmitAsConstant(const MemberExpr *ME) {
1888 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1889 return tryEmitAsConstant(DRE);
1890 return ConstantEmission();
1891 }
1892
emitScalarConstant(const CodeGenFunction::ConstantEmission & Constant,Expr * E)1893 llvm::Value *CodeGenFunction::emitScalarConstant(
1894 const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1895 assert(Constant && "not a constant");
1896 if (Constant.isReference())
1897 return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1898 E->getExprLoc())
1899 .getScalarVal();
1900 return Constant.getValue();
1901 }
1902
EmitLoadOfScalar(LValue lvalue,SourceLocation Loc)1903 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1904 SourceLocation Loc) {
1905 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(),
1906 lvalue.getType(), Loc, lvalue.getBaseInfo(),
1907 lvalue.getTBAAInfo(), lvalue.isNontemporal());
1908 }
1909
getRangeForType(CodeGenFunction & CGF,QualType Ty,llvm::APInt & Min,llvm::APInt & End,bool StrictEnums,bool IsBool)1910 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1911 llvm::APInt &Min, llvm::APInt &End,
1912 bool StrictEnums, bool IsBool) {
1913 const EnumType *ET = Ty->getAs<EnumType>();
1914 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1915 ET && !ET->getDecl()->isFixed();
1916 if (!IsBool && !IsRegularCPlusPlusEnum)
1917 return false;
1918
1919 if (IsBool) {
1920 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1921 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1922 } else {
1923 const EnumDecl *ED = ET->getDecl();
1924 ED->getValueRange(End, Min);
1925 }
1926 return true;
1927 }
1928
getRangeForLoadFromType(QualType Ty)1929 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1930 llvm::APInt Min, End;
1931 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1932 Ty->hasBooleanRepresentation() && !Ty->isVectorType()))
1933 return nullptr;
1934
1935 llvm::MDBuilder MDHelper(getLLVMContext());
1936 return MDHelper.createRange(Min, End);
1937 }
1938
maybeAttachRangeForLoad(llvm::LoadInst * Load,QualType Ty,SourceLocation Loc)1939 void CodeGenFunction::maybeAttachRangeForLoad(llvm::LoadInst *Load, QualType Ty,
1940 SourceLocation Loc) {
1941 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1942 // In order to prevent the optimizer from throwing away the check, don't
1943 // attach range metadata to the load.
1944 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
1945 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty)) {
1946 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1947 Load->setMetadata(llvm::LLVMContext::MD_noundef,
1948 llvm::MDNode::get(CGM.getLLVMContext(), {}));
1949 }
1950 }
1951 }
1952
EmitScalarRangeCheck(llvm::Value * Value,QualType Ty,SourceLocation Loc)1953 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1954 SourceLocation Loc) {
1955 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1956 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1957 if (!HasBoolCheck && !HasEnumCheck)
1958 return false;
1959
1960 bool IsBool = (Ty->hasBooleanRepresentation() && !Ty->isVectorType()) ||
1961 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1962 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1963 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1964 if (!NeedsBoolCheck && !NeedsEnumCheck)
1965 return false;
1966
1967 // Single-bit booleans don't need to be checked. Special-case this to avoid
1968 // a bit width mismatch when handling bitfield values. This is handled by
1969 // EmitFromMemory for the non-bitfield case.
1970 if (IsBool &&
1971 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1972 return false;
1973
1974 if (NeedsEnumCheck &&
1975 getContext().isTypeIgnoredBySanitizer(SanitizerKind::Enum, Ty))
1976 return false;
1977
1978 llvm::APInt Min, End;
1979 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1980 return true;
1981
1982 SanitizerKind::SanitizerOrdinal Kind =
1983 NeedsEnumCheck ? SanitizerKind::SO_Enum : SanitizerKind::SO_Bool;
1984
1985 auto &Ctx = getLLVMContext();
1986 auto CheckHandler = SanitizerHandler::LoadInvalidValue;
1987 SanitizerDebugLocation SanScope(this, {Kind}, CheckHandler);
1988 llvm::Value *Check;
1989 --End;
1990 if (!Min) {
1991 Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1992 } else {
1993 llvm::Value *Upper =
1994 Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1995 llvm::Value *Lower =
1996 Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1997 Check = Builder.CreateAnd(Upper, Lower);
1998 }
1999 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
2000 EmitCheckTypeDescriptor(Ty)};
2001 EmitCheck(std::make_pair(Check, Kind), CheckHandler, StaticArgs, Value);
2002 return true;
2003 }
2004
EmitLoadOfScalar(Address Addr,bool Volatile,QualType Ty,SourceLocation Loc,LValueBaseInfo BaseInfo,TBAAAccessInfo TBAAInfo,bool isNontemporal)2005 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
2006 QualType Ty,
2007 SourceLocation Loc,
2008 LValueBaseInfo BaseInfo,
2009 TBAAAccessInfo TBAAInfo,
2010 bool isNontemporal) {
2011 if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr.getBasePointer()))
2012 if (GV->isThreadLocal())
2013 Addr = Addr.withPointer(Builder.CreateThreadLocalAddress(GV),
2014 NotKnownNonNull);
2015
2016 if (const auto *ClangVecTy = Ty->getAs<VectorType>()) {
2017 // Boolean vectors use `iN` as storage type.
2018 if (ClangVecTy->isPackedVectorBoolType(getContext())) {
2019 llvm::Type *ValTy = ConvertType(Ty);
2020 unsigned ValNumElems =
2021 cast<llvm::FixedVectorType>(ValTy)->getNumElements();
2022 // Load the `iP` storage object (P is the padded vector size).
2023 auto *RawIntV = Builder.CreateLoad(Addr, Volatile, "load_bits");
2024 const auto *RawIntTy = RawIntV->getType();
2025 assert(RawIntTy->isIntegerTy() && "compressed iN storage for bitvectors");
2026 // Bitcast iP --> <P x i1>.
2027 auto *PaddedVecTy = llvm::FixedVectorType::get(
2028 Builder.getInt1Ty(), RawIntTy->getPrimitiveSizeInBits());
2029 llvm::Value *V = Builder.CreateBitCast(RawIntV, PaddedVecTy);
2030 // Shuffle <P x i1> --> <N x i1> (N is the actual bit size).
2031 V = emitBoolVecConversion(V, ValNumElems, "extractvec");
2032
2033 return EmitFromMemory(V, Ty);
2034 }
2035
2036 // Handles vectors of sizes that are likely to be expanded to a larger size
2037 // to optimize performance.
2038 auto *VTy = cast<llvm::FixedVectorType>(Addr.getElementType());
2039 auto *NewVecTy =
2040 CGM.getABIInfo().getOptimalVectorMemoryType(VTy, getLangOpts());
2041
2042 if (VTy != NewVecTy) {
2043 Address Cast = Addr.withElementType(NewVecTy);
2044 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVecN");
2045 unsigned OldNumElements = VTy->getNumElements();
2046 SmallVector<int, 16> Mask(OldNumElements);
2047 std::iota(Mask.begin(), Mask.end(), 0);
2048 V = Builder.CreateShuffleVector(V, Mask, "extractVec");
2049 return EmitFromMemory(V, Ty);
2050 }
2051 }
2052
2053 // Atomic operations have to be done on integral types.
2054 LValue AtomicLValue =
2055 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
2056 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
2057 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
2058 }
2059
2060 Addr =
2061 Addr.withElementType(convertTypeForLoadStore(Ty, Addr.getElementType()));
2062
2063 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
2064 if (isNontemporal) {
2065 llvm::MDNode *Node = llvm::MDNode::get(
2066 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
2067 Load->setMetadata(llvm::LLVMContext::MD_nontemporal, Node);
2068 }
2069
2070 CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
2071
2072 maybeAttachRangeForLoad(Load, Ty, Loc);
2073
2074 return EmitFromMemory(Load, Ty);
2075 }
2076
2077 /// Converts a scalar value from its primary IR type (as returned
2078 /// by ConvertType) to its load/store type (as returned by
2079 /// convertTypeForLoadStore).
EmitToMemory(llvm::Value * Value,QualType Ty)2080 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
2081 if (auto *AtomicTy = Ty->getAs<AtomicType>())
2082 Ty = AtomicTy->getValueType();
2083
2084 if (Ty->isExtVectorBoolType()) {
2085 llvm::Type *StoreTy = convertTypeForLoadStore(Ty, Value->getType());
2086 if (StoreTy->isVectorTy() && StoreTy->getScalarSizeInBits() >
2087 Value->getType()->getScalarSizeInBits())
2088 return Builder.CreateZExt(Value, StoreTy);
2089
2090 // Expand to the memory bit width.
2091 unsigned MemNumElems = StoreTy->getPrimitiveSizeInBits();
2092 // <N x i1> --> <P x i1>.
2093 Value = emitBoolVecConversion(Value, MemNumElems, "insertvec");
2094 // <P x i1> --> iP.
2095 Value = Builder.CreateBitCast(Value, StoreTy);
2096 }
2097
2098 if (Ty->hasBooleanRepresentation() || Ty->isBitIntType()) {
2099 llvm::Type *StoreTy = convertTypeForLoadStore(Ty, Value->getType());
2100 bool Signed = Ty->isSignedIntegerOrEnumerationType();
2101 return Builder.CreateIntCast(Value, StoreTy, Signed, "storedv");
2102 }
2103
2104 return Value;
2105 }
2106
2107 /// Converts a scalar value from its load/store type (as returned
2108 /// by convertTypeForLoadStore) to its primary IR type (as returned
2109 /// by ConvertType).
EmitFromMemory(llvm::Value * Value,QualType Ty)2110 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
2111 if (auto *AtomicTy = Ty->getAs<AtomicType>())
2112 Ty = AtomicTy->getValueType();
2113
2114 if (Ty->isPackedVectorBoolType(getContext())) {
2115 const auto *RawIntTy = Value->getType();
2116
2117 // Bitcast iP --> <P x i1>.
2118 auto *PaddedVecTy = llvm::FixedVectorType::get(
2119 Builder.getInt1Ty(), RawIntTy->getPrimitiveSizeInBits());
2120 auto *V = Builder.CreateBitCast(Value, PaddedVecTy);
2121 // Shuffle <P x i1> --> <N x i1> (N is the actual bit size).
2122 llvm::Type *ValTy = ConvertType(Ty);
2123 unsigned ValNumElems = cast<llvm::FixedVectorType>(ValTy)->getNumElements();
2124 return emitBoolVecConversion(V, ValNumElems, "extractvec");
2125 }
2126
2127 llvm::Type *ResTy = ConvertType(Ty);
2128 if (Ty->hasBooleanRepresentation() || Ty->isBitIntType() ||
2129 Ty->isExtVectorBoolType())
2130 return Builder.CreateTrunc(Value, ResTy, "loadedv");
2131
2132 return Value;
2133 }
2134
2135 // Convert the pointer of \p Addr to a pointer to a vector (the value type of
2136 // MatrixType), if it points to a array (the memory type of MatrixType).
MaybeConvertMatrixAddress(RawAddress Addr,CodeGenFunction & CGF,bool IsVector=true)2137 static RawAddress MaybeConvertMatrixAddress(RawAddress Addr,
2138 CodeGenFunction &CGF,
2139 bool IsVector = true) {
2140 auto *ArrayTy = dyn_cast<llvm::ArrayType>(Addr.getElementType());
2141 if (ArrayTy && IsVector) {
2142 auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
2143 ArrayTy->getNumElements());
2144
2145 return Addr.withElementType(VectorTy);
2146 }
2147 auto *VectorTy = dyn_cast<llvm::VectorType>(Addr.getElementType());
2148 if (VectorTy && !IsVector) {
2149 auto *ArrayTy = llvm::ArrayType::get(
2150 VectorTy->getElementType(),
2151 cast<llvm::FixedVectorType>(VectorTy)->getNumElements());
2152
2153 return Addr.withElementType(ArrayTy);
2154 }
2155
2156 return Addr;
2157 }
2158
2159 // Emit a store of a matrix LValue. This may require casting the original
2160 // pointer to memory address (ArrayType) to a pointer to the value type
2161 // (VectorType).
EmitStoreOfMatrixScalar(llvm::Value * value,LValue lvalue,bool isInit,CodeGenFunction & CGF)2162 static void EmitStoreOfMatrixScalar(llvm::Value *value, LValue lvalue,
2163 bool isInit, CodeGenFunction &CGF) {
2164 Address Addr = MaybeConvertMatrixAddress(lvalue.getAddress(), CGF,
2165 value->getType()->isVectorTy());
2166 CGF.EmitStoreOfScalar(value, Addr, lvalue.isVolatile(), lvalue.getType(),
2167 lvalue.getBaseInfo(), lvalue.getTBAAInfo(), isInit,
2168 lvalue.isNontemporal());
2169 }
2170
EmitStoreOfScalar(llvm::Value * Value,Address Addr,bool Volatile,QualType Ty,LValueBaseInfo BaseInfo,TBAAAccessInfo TBAAInfo,bool isInit,bool isNontemporal)2171 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
2172 bool Volatile, QualType Ty,
2173 LValueBaseInfo BaseInfo,
2174 TBAAAccessInfo TBAAInfo,
2175 bool isInit, bool isNontemporal) {
2176 if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr.getBasePointer()))
2177 if (GV->isThreadLocal())
2178 Addr = Addr.withPointer(Builder.CreateThreadLocalAddress(GV),
2179 NotKnownNonNull);
2180
2181 // Handles vectors of sizes that are likely to be expanded to a larger size
2182 // to optimize performance.
2183 llvm::Type *SrcTy = Value->getType();
2184 if (const auto *ClangVecTy = Ty->getAs<VectorType>()) {
2185 if (auto *VecTy = dyn_cast<llvm::FixedVectorType>(SrcTy)) {
2186 auto *NewVecTy =
2187 CGM.getABIInfo().getOptimalVectorMemoryType(VecTy, getLangOpts());
2188 if (!ClangVecTy->isPackedVectorBoolType(getContext()) &&
2189 VecTy != NewVecTy) {
2190 SmallVector<int, 16> Mask(NewVecTy->getNumElements(), -1);
2191 std::iota(Mask.begin(), Mask.begin() + VecTy->getNumElements(), 0);
2192 Value = Builder.CreateShuffleVector(Value, Mask, "extractVec");
2193 SrcTy = NewVecTy;
2194 }
2195 if (Addr.getElementType() != SrcTy)
2196 Addr = Addr.withElementType(SrcTy);
2197 }
2198 }
2199
2200 Value = EmitToMemory(Value, Ty);
2201
2202 LValue AtomicLValue =
2203 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
2204 if (Ty->isAtomicType() ||
2205 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
2206 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
2207 return;
2208 }
2209
2210 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
2211 addInstToCurrentSourceAtom(Store, Value);
2212
2213 if (isNontemporal) {
2214 llvm::MDNode *Node =
2215 llvm::MDNode::get(Store->getContext(),
2216 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
2217 Store->setMetadata(llvm::LLVMContext::MD_nontemporal, Node);
2218 }
2219
2220 CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
2221 }
2222
EmitStoreOfScalar(llvm::Value * value,LValue lvalue,bool isInit)2223 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
2224 bool isInit) {
2225 if (lvalue.getType()->isConstantMatrixType()) {
2226 EmitStoreOfMatrixScalar(value, lvalue, isInit, *this);
2227 return;
2228 }
2229
2230 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
2231 lvalue.getType(), lvalue.getBaseInfo(),
2232 lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
2233 }
2234
2235 // Emit a load of a LValue of matrix type. This may require casting the pointer
2236 // to memory address (ArrayType) to a pointer to the value type (VectorType).
EmitLoadOfMatrixLValue(LValue LV,SourceLocation Loc,CodeGenFunction & CGF)2237 static RValue EmitLoadOfMatrixLValue(LValue LV, SourceLocation Loc,
2238 CodeGenFunction &CGF) {
2239 assert(LV.getType()->isConstantMatrixType());
2240 Address Addr = MaybeConvertMatrixAddress(LV.getAddress(), CGF);
2241 LV.setAddress(Addr);
2242 return RValue::get(CGF.EmitLoadOfScalar(LV, Loc));
2243 }
2244
EmitLoadOfAnyValue(LValue LV,AggValueSlot Slot,SourceLocation Loc)2245 RValue CodeGenFunction::EmitLoadOfAnyValue(LValue LV, AggValueSlot Slot,
2246 SourceLocation Loc) {
2247 QualType Ty = LV.getType();
2248 switch (getEvaluationKind(Ty)) {
2249 case TEK_Scalar:
2250 return EmitLoadOfLValue(LV, Loc);
2251 case TEK_Complex:
2252 return RValue::getComplex(EmitLoadOfComplex(LV, Loc));
2253 case TEK_Aggregate:
2254 EmitAggFinalDestCopy(Ty, Slot, LV, EVK_NonRValue);
2255 return Slot.asRValue();
2256 }
2257 llvm_unreachable("bad evaluation kind");
2258 }
2259
2260 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
2261 /// method emits the address of the lvalue, then loads the result as an rvalue,
2262 /// returning the rvalue.
EmitLoadOfLValue(LValue LV,SourceLocation Loc)2263 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
2264 // Load from __ptrauth.
2265 if (PointerAuthQualifier PtrAuth = LV.getQuals().getPointerAuth()) {
2266 LV.getQuals().removePointerAuth();
2267 llvm::Value *Value = EmitLoadOfLValue(LV, Loc).getScalarVal();
2268 return RValue::get(EmitPointerAuthUnqualify(PtrAuth, Value, LV.getType(),
2269 LV.getAddress(),
2270 /*known nonnull*/ false));
2271 }
2272
2273 if (LV.isObjCWeak()) {
2274 // load of a __weak object.
2275 Address AddrWeakObj = LV.getAddress();
2276 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
2277 AddrWeakObj));
2278 }
2279 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
2280 // In MRC mode, we do a load+autorelease.
2281 if (!getLangOpts().ObjCAutoRefCount) {
2282 return RValue::get(EmitARCLoadWeak(LV.getAddress()));
2283 }
2284
2285 // In ARC mode, we load retained and then consume the value.
2286 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress());
2287 Object = EmitObjCConsumeObject(LV.getType(), Object);
2288 return RValue::get(Object);
2289 }
2290
2291 if (LV.isSimple()) {
2292 assert(!LV.getType()->isFunctionType());
2293
2294 if (LV.getType()->isConstantMatrixType())
2295 return EmitLoadOfMatrixLValue(LV, Loc, *this);
2296
2297 // Everything needs a load.
2298 return RValue::get(EmitLoadOfScalar(LV, Loc));
2299 }
2300
2301 if (LV.isVectorElt()) {
2302 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
2303 LV.isVolatileQualified());
2304 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
2305 "vecext"));
2306 }
2307
2308 // If this is a reference to a subset of the elements of a vector, either
2309 // shuffle the input or extract/insert them as appropriate.
2310 if (LV.isExtVectorElt()) {
2311 return EmitLoadOfExtVectorElementLValue(LV);
2312 }
2313
2314 // Global Register variables always invoke intrinsics
2315 if (LV.isGlobalReg())
2316 return EmitLoadOfGlobalRegLValue(LV);
2317
2318 if (LV.isMatrixElt()) {
2319 llvm::Value *Idx = LV.getMatrixIdx();
2320 if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
2321 const auto *const MatTy = LV.getType()->castAs<ConstantMatrixType>();
2322 llvm::MatrixBuilder MB(Builder);
2323 MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
2324 }
2325 llvm::LoadInst *Load =
2326 Builder.CreateLoad(LV.getMatrixAddress(), LV.isVolatileQualified());
2327 return RValue::get(Builder.CreateExtractElement(Load, Idx, "matrixext"));
2328 }
2329
2330 assert(LV.isBitField() && "Unknown LValue type!");
2331 return EmitLoadOfBitfieldLValue(LV, Loc);
2332 }
2333
EmitLoadOfBitfieldLValue(LValue LV,SourceLocation Loc)2334 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
2335 SourceLocation Loc) {
2336 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
2337
2338 // Get the output type.
2339 llvm::Type *ResLTy = ConvertType(LV.getType());
2340
2341 Address Ptr = LV.getBitFieldAddress();
2342 llvm::Value *Val =
2343 Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
2344
2345 bool UseVolatile = LV.isVolatileQualified() &&
2346 Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
2347 const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
2348 const unsigned StorageSize =
2349 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
2350 if (Info.IsSigned) {
2351 assert(static_cast<unsigned>(Offset + Info.Size) <= StorageSize);
2352 unsigned HighBits = StorageSize - Offset - Info.Size;
2353 if (HighBits)
2354 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
2355 if (Offset + HighBits)
2356 Val = Builder.CreateAShr(Val, Offset + HighBits, "bf.ashr");
2357 } else {
2358 if (Offset)
2359 Val = Builder.CreateLShr(Val, Offset, "bf.lshr");
2360 if (static_cast<unsigned>(Offset) + Info.Size < StorageSize)
2361 Val = Builder.CreateAnd(
2362 Val, llvm::APInt::getLowBitsSet(StorageSize, Info.Size), "bf.clear");
2363 }
2364 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
2365 EmitScalarRangeCheck(Val, LV.getType(), Loc);
2366 return RValue::get(Val);
2367 }
2368
2369 // If this is a reference to a subset of the elements of a vector, create an
2370 // appropriate shufflevector.
EmitLoadOfExtVectorElementLValue(LValue LV)2371 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
2372 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
2373 LV.isVolatileQualified());
2374
2375 // HLSL allows treating scalars as one-element vectors. Converting the scalar
2376 // IR value to a vector here allows the rest of codegen to behave as normal.
2377 if (getLangOpts().HLSL && !Vec->getType()->isVectorTy()) {
2378 llvm::Type *DstTy = llvm::FixedVectorType::get(Vec->getType(), 1);
2379 llvm::Value *Zero = llvm::Constant::getNullValue(CGM.Int64Ty);
2380 Vec = Builder.CreateInsertElement(DstTy, Vec, Zero, "cast.splat");
2381 }
2382
2383 const llvm::Constant *Elts = LV.getExtVectorElts();
2384
2385 // If the result of the expression is a non-vector type, we must be extracting
2386 // a single element. Just codegen as an extractelement.
2387 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
2388 if (!ExprVT) {
2389 unsigned InIdx = getAccessedFieldNo(0, Elts);
2390 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2391
2392 llvm::Value *Element = Builder.CreateExtractElement(Vec, Elt);
2393
2394 llvm::Type *LVTy = ConvertType(LV.getType());
2395 if (Element->getType()->getPrimitiveSizeInBits() >
2396 LVTy->getPrimitiveSizeInBits())
2397 Element = Builder.CreateTrunc(Element, LVTy);
2398
2399 return RValue::get(Element);
2400 }
2401
2402 // Always use shuffle vector to try to retain the original program structure
2403 unsigned NumResultElts = ExprVT->getNumElements();
2404
2405 SmallVector<int, 4> Mask;
2406 for (unsigned i = 0; i != NumResultElts; ++i)
2407 Mask.push_back(getAccessedFieldNo(i, Elts));
2408
2409 Vec = Builder.CreateShuffleVector(Vec, Mask);
2410
2411 if (LV.getType()->isExtVectorBoolType())
2412 Vec = Builder.CreateTrunc(Vec, ConvertType(LV.getType()), "truncv");
2413
2414 return RValue::get(Vec);
2415 }
2416
2417 /// Generates lvalue for partial ext_vector access.
EmitExtVectorElementLValue(LValue LV)2418 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
2419 Address VectorAddress = LV.getExtVectorAddress();
2420 QualType EQT = LV.getType()->castAs<VectorType>()->getElementType();
2421 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
2422
2423 Address CastToPointerElement = VectorAddress.withElementType(VectorElementTy);
2424
2425 const llvm::Constant *Elts = LV.getExtVectorElts();
2426 unsigned ix = getAccessedFieldNo(0, Elts);
2427
2428 Address VectorBasePtrPlusIx =
2429 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
2430 "vector.elt");
2431
2432 return VectorBasePtrPlusIx;
2433 }
2434
2435 /// Load of global named registers are always calls to intrinsics.
EmitLoadOfGlobalRegLValue(LValue LV)2436 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
2437 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
2438 "Bad type for register variable");
2439 llvm::MDNode *RegName = cast<llvm::MDNode>(
2440 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
2441
2442 // We accept integer and pointer types only
2443 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
2444 llvm::Type *Ty = OrigTy;
2445 if (OrigTy->isPointerTy())
2446 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2447 llvm::Type *Types[] = { Ty };
2448
2449 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
2450 llvm::Value *Call = Builder.CreateCall(
2451 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
2452 if (OrigTy->isPointerTy())
2453 Call = Builder.CreateIntToPtr(Call, OrigTy);
2454 return RValue::get(Call);
2455 }
2456
2457 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
2458 /// lvalue, where both are guaranteed to the have the same type, and that type
2459 /// is 'Ty'.
EmitStoreThroughLValue(RValue Src,LValue Dst,bool isInit)2460 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
2461 bool isInit) {
2462 if (!Dst.isSimple()) {
2463 if (Dst.isVectorElt()) {
2464 // Read/modify/write the vector, inserting the new element.
2465 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
2466 Dst.isVolatileQualified());
2467 llvm::Type *VecTy = Vec->getType();
2468 llvm::Value *SrcVal = Src.getScalarVal();
2469
2470 if (SrcVal->getType()->getPrimitiveSizeInBits() <
2471 VecTy->getScalarSizeInBits())
2472 SrcVal = Builder.CreateZExt(SrcVal, VecTy->getScalarType());
2473
2474 auto *IRStoreTy = dyn_cast<llvm::IntegerType>(Vec->getType());
2475 if (IRStoreTy) {
2476 auto *IRVecTy = llvm::FixedVectorType::get(
2477 Builder.getInt1Ty(), IRStoreTy->getPrimitiveSizeInBits());
2478 Vec = Builder.CreateBitCast(Vec, IRVecTy);
2479 // iN --> <N x i1>.
2480 }
2481
2482 // Allow inserting `<1 x T>` into an `<N x T>`. It can happen with scalar
2483 // types which are mapped to vector LLVM IR types (e.g. for implementing
2484 // an ABI).
2485 if (auto *EltTy = dyn_cast<llvm::FixedVectorType>(SrcVal->getType());
2486 EltTy && EltTy->getNumElements() == 1)
2487 SrcVal = Builder.CreateBitCast(SrcVal, EltTy->getElementType());
2488
2489 Vec = Builder.CreateInsertElement(Vec, SrcVal, Dst.getVectorIdx(),
2490 "vecins");
2491 if (IRStoreTy) {
2492 // <N x i1> --> <iN>.
2493 Vec = Builder.CreateBitCast(Vec, IRStoreTy);
2494 }
2495
2496 auto *I = Builder.CreateStore(Vec, Dst.getVectorAddress(),
2497 Dst.isVolatileQualified());
2498 addInstToCurrentSourceAtom(I, Vec);
2499 return;
2500 }
2501
2502 // If this is an update of extended vector elements, insert them as
2503 // appropriate.
2504 if (Dst.isExtVectorElt())
2505 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
2506
2507 if (Dst.isGlobalReg())
2508 return EmitStoreThroughGlobalRegLValue(Src, Dst);
2509
2510 if (Dst.isMatrixElt()) {
2511 llvm::Value *Idx = Dst.getMatrixIdx();
2512 if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
2513 const auto *const MatTy = Dst.getType()->castAs<ConstantMatrixType>();
2514 llvm::MatrixBuilder MB(Builder);
2515 MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
2516 }
2517 llvm::Instruction *Load = Builder.CreateLoad(Dst.getMatrixAddress());
2518 llvm::Value *Vec =
2519 Builder.CreateInsertElement(Load, Src.getScalarVal(), Idx, "matins");
2520 auto *I = Builder.CreateStore(Vec, Dst.getMatrixAddress(),
2521 Dst.isVolatileQualified());
2522 addInstToCurrentSourceAtom(I, Vec);
2523 return;
2524 }
2525
2526 assert(Dst.isBitField() && "Unknown LValue type");
2527 return EmitStoreThroughBitfieldLValue(Src, Dst);
2528 }
2529
2530 // Handle __ptrauth qualification by re-signing the value.
2531 if (PointerAuthQualifier PointerAuth = Dst.getQuals().getPointerAuth()) {
2532 Src = RValue::get(EmitPointerAuthQualify(PointerAuth, Src.getScalarVal(),
2533 Dst.getType(), Dst.getAddress(),
2534 /*known nonnull*/ false));
2535 }
2536
2537 // There's special magic for assigning into an ARC-qualified l-value.
2538 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
2539 switch (Lifetime) {
2540 case Qualifiers::OCL_None:
2541 llvm_unreachable("present but none");
2542
2543 case Qualifiers::OCL_ExplicitNone:
2544 // nothing special
2545 break;
2546
2547 case Qualifiers::OCL_Strong:
2548 if (isInit) {
2549 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
2550 break;
2551 }
2552 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
2553 return;
2554
2555 case Qualifiers::OCL_Weak:
2556 if (isInit)
2557 // Initialize and then skip the primitive store.
2558 EmitARCInitWeak(Dst.getAddress(), Src.getScalarVal());
2559 else
2560 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(),
2561 /*ignore*/ true);
2562 return;
2563
2564 case Qualifiers::OCL_Autoreleasing:
2565 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
2566 Src.getScalarVal()));
2567 // fall into the normal path
2568 break;
2569 }
2570 }
2571
2572 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
2573 // load of a __weak object.
2574 Address LvalueDst = Dst.getAddress();
2575 llvm::Value *src = Src.getScalarVal();
2576 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
2577 return;
2578 }
2579
2580 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
2581 // load of a __strong object.
2582 Address LvalueDst = Dst.getAddress();
2583 llvm::Value *src = Src.getScalarVal();
2584 if (Dst.isObjCIvar()) {
2585 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2586 llvm::Type *ResultType = IntPtrTy;
2587 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
2588 llvm::Value *RHS = dst.emitRawPointer(*this);
2589 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2590 llvm::Value *LHS = Builder.CreatePtrToInt(LvalueDst.emitRawPointer(*this),
2591 ResultType, "sub.ptr.lhs.cast");
2592 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2593 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst, BytesBetween);
2594 } else if (Dst.isGlobalObjCRef()) {
2595 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2596 Dst.isThreadLocalRef());
2597 }
2598 else
2599 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2600 return;
2601 }
2602
2603 assert(Src.isScalar() && "Can't emit an agg store with this method");
2604 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2605 }
2606
EmitStoreThroughBitfieldLValue(RValue Src,LValue Dst,llvm::Value ** Result)2607 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
2608 llvm::Value **Result) {
2609 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2610 llvm::Type *ResLTy = convertTypeForLoadStore(Dst.getType());
2611 Address Ptr = Dst.getBitFieldAddress();
2612
2613 // Get the source value, truncated to the width of the bit-field.
2614 llvm::Value *SrcVal = Src.getScalarVal();
2615
2616 // Cast the source to the storage type and shift it into place.
2617 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2618 /*isSigned=*/false);
2619 llvm::Value *MaskedVal = SrcVal;
2620
2621 const bool UseVolatile =
2622 CGM.getCodeGenOpts().AAPCSBitfieldWidth && Dst.isVolatileQualified() &&
2623 Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
2624 const unsigned StorageSize =
2625 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
2626 const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
2627 // See if there are other bits in the bitfield's storage we'll need to load
2628 // and mask together with source before storing.
2629 if (StorageSize != Info.Size) {
2630 assert(StorageSize > Info.Size && "Invalid bitfield size.");
2631 llvm::Value *Val =
2632 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2633
2634 // Mask the source value as needed.
2635 if (!Dst.getType()->hasBooleanRepresentation())
2636 SrcVal = Builder.CreateAnd(
2637 SrcVal, llvm::APInt::getLowBitsSet(StorageSize, Info.Size),
2638 "bf.value");
2639 MaskedVal = SrcVal;
2640 if (Offset)
2641 SrcVal = Builder.CreateShl(SrcVal, Offset, "bf.shl");
2642
2643 // Mask out the original value.
2644 Val = Builder.CreateAnd(
2645 Val, ~llvm::APInt::getBitsSet(StorageSize, Offset, Offset + Info.Size),
2646 "bf.clear");
2647
2648 // Or together the unchanged values and the source value.
2649 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2650 } else {
2651 assert(Offset == 0);
2652 // According to the AACPS:
2653 // When a volatile bit-field is written, and its container does not overlap
2654 // with any non-bit-field member, its container must be read exactly once
2655 // and written exactly once using the access width appropriate to the type
2656 // of the container. The two accesses are not atomic.
2657 if (Dst.isVolatileQualified() && isAAPCS(CGM.getTarget()) &&
2658 CGM.getCodeGenOpts().ForceAAPCSBitfieldLoad)
2659 Builder.CreateLoad(Ptr, true, "bf.load");
2660 }
2661
2662 // Write the new value back out.
2663 auto *I = Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2664 addInstToCurrentSourceAtom(I, SrcVal);
2665
2666 // Return the new value of the bit-field, if requested.
2667 if (Result) {
2668 llvm::Value *ResultVal = MaskedVal;
2669
2670 // Sign extend the value if needed.
2671 if (Info.IsSigned) {
2672 assert(Info.Size <= StorageSize);
2673 unsigned HighBits = StorageSize - Info.Size;
2674 if (HighBits) {
2675 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2676 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2677 }
2678 }
2679
2680 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2681 "bf.result.cast");
2682 *Result = EmitFromMemory(ResultVal, Dst.getType());
2683 }
2684 }
2685
EmitStoreThroughExtVectorComponentLValue(RValue Src,LValue Dst)2686 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
2687 LValue Dst) {
2688 llvm::Value *SrcVal = Src.getScalarVal();
2689 Address DstAddr = Dst.getExtVectorAddress();
2690 if (DstAddr.getElementType()->getScalarSizeInBits() >
2691 SrcVal->getType()->getScalarSizeInBits())
2692 SrcVal = Builder.CreateZExt(
2693 SrcVal, convertTypeForLoadStore(Dst.getType(), SrcVal->getType()));
2694
2695 // HLSL allows storing to scalar values through ExtVector component LValues.
2696 // To support this we need to handle the case where the destination address is
2697 // a scalar.
2698 if (!DstAddr.getElementType()->isVectorTy()) {
2699 assert(!Dst.getType()->isVectorType() &&
2700 "this should only occur for non-vector l-values");
2701 Builder.CreateStore(SrcVal, DstAddr, Dst.isVolatileQualified());
2702 return;
2703 }
2704
2705 // This access turns into a read/modify/write of the vector. Load the input
2706 // value now.
2707 llvm::Value *Vec = Builder.CreateLoad(DstAddr, Dst.isVolatileQualified());
2708 llvm::Type *VecTy = Vec->getType();
2709 const llvm::Constant *Elts = Dst.getExtVectorElts();
2710
2711 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2712 unsigned NumSrcElts = VTy->getNumElements();
2713 unsigned NumDstElts = cast<llvm::FixedVectorType>(VecTy)->getNumElements();
2714 if (NumDstElts == NumSrcElts) {
2715 // Use shuffle vector is the src and destination are the same number of
2716 // elements and restore the vector mask since it is on the side it will be
2717 // stored.
2718 SmallVector<int, 4> Mask(NumDstElts);
2719 for (unsigned i = 0; i != NumSrcElts; ++i)
2720 Mask[getAccessedFieldNo(i, Elts)] = i;
2721
2722 Vec = Builder.CreateShuffleVector(SrcVal, Mask);
2723 } else if (NumDstElts > NumSrcElts) {
2724 // Extended the source vector to the same length and then shuffle it
2725 // into the destination.
2726 // FIXME: since we're shuffling with undef, can we just use the indices
2727 // into that? This could be simpler.
2728 SmallVector<int, 4> ExtMask;
2729 for (unsigned i = 0; i != NumSrcElts; ++i)
2730 ExtMask.push_back(i);
2731 ExtMask.resize(NumDstElts, -1);
2732 llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal, ExtMask);
2733 // build identity
2734 SmallVector<int, 4> Mask;
2735 for (unsigned i = 0; i != NumDstElts; ++i)
2736 Mask.push_back(i);
2737
2738 // When the vector size is odd and .odd or .hi is used, the last element
2739 // of the Elts constant array will be one past the size of the vector.
2740 // Ignore the last element here, if it is greater than the mask size.
2741 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2742 NumSrcElts--;
2743
2744 // modify when what gets shuffled in
2745 for (unsigned i = 0; i != NumSrcElts; ++i)
2746 Mask[getAccessedFieldNo(i, Elts)] = i + NumDstElts;
2747 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, Mask);
2748 } else {
2749 // We should never shorten the vector
2750 llvm_unreachable("unexpected shorten vector length");
2751 }
2752 } else {
2753 // If the Src is a scalar (not a vector), and the target is a vector it must
2754 // be updating one element.
2755 unsigned InIdx = getAccessedFieldNo(0, Elts);
2756 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2757
2758 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2759 }
2760
2761 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
2762 Dst.isVolatileQualified());
2763 }
2764
2765 /// Store of global named registers are always calls to intrinsics.
EmitStoreThroughGlobalRegLValue(RValue Src,LValue Dst)2766 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
2767 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2768 "Bad type for register variable");
2769 llvm::MDNode *RegName = cast<llvm::MDNode>(
2770 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2771 assert(RegName && "Register LValue is not metadata");
2772
2773 // We accept integer and pointer types only
2774 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2775 llvm::Type *Ty = OrigTy;
2776 if (OrigTy->isPointerTy())
2777 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2778 llvm::Type *Types[] = { Ty };
2779
2780 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2781 llvm::Value *Value = Src.getScalarVal();
2782 if (OrigTy->isPointerTy())
2783 Value = Builder.CreatePtrToInt(Value, Ty);
2784 Builder.CreateCall(
2785 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2786 }
2787
2788 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2789 // generating write-barries API. It is currently a global, ivar,
2790 // or neither.
setObjCGCLValueClass(const ASTContext & Ctx,const Expr * E,LValue & LV,bool IsMemberAccess=false)2791 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2792 LValue &LV,
2793 bool IsMemberAccess=false) {
2794 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2795 return;
2796
2797 if (isa<ObjCIvarRefExpr>(E)) {
2798 QualType ExpTy = E->getType();
2799 if (IsMemberAccess && ExpTy->isPointerType()) {
2800 // If ivar is a structure pointer, assigning to field of
2801 // this struct follows gcc's behavior and makes it a non-ivar
2802 // writer-barrier conservatively.
2803 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2804 if (ExpTy->isRecordType()) {
2805 LV.setObjCIvar(false);
2806 return;
2807 }
2808 }
2809 LV.setObjCIvar(true);
2810 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2811 LV.setBaseIvarExp(Exp->getBase());
2812 LV.setObjCArray(E->getType()->isArrayType());
2813 return;
2814 }
2815
2816 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2817 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2818 if (VD->hasGlobalStorage()) {
2819 LV.setGlobalObjCRef(true);
2820 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2821 }
2822 }
2823 LV.setObjCArray(E->getType()->isArrayType());
2824 return;
2825 }
2826
2827 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2828 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2829 return;
2830 }
2831
2832 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2833 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2834 if (LV.isObjCIvar()) {
2835 // If cast is to a structure pointer, follow gcc's behavior and make it
2836 // a non-ivar write-barrier.
2837 QualType ExpTy = E->getType();
2838 if (ExpTy->isPointerType())
2839 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2840 if (ExpTy->isRecordType())
2841 LV.setObjCIvar(false);
2842 }
2843 return;
2844 }
2845
2846 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2847 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2848 return;
2849 }
2850
2851 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2852 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2853 return;
2854 }
2855
2856 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2857 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2858 return;
2859 }
2860
2861 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2862 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2863 return;
2864 }
2865
2866 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2867 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2868 if (LV.isObjCIvar() && !LV.isObjCArray())
2869 // Using array syntax to assigning to what an ivar points to is not
2870 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2871 LV.setObjCIvar(false);
2872 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2873 // Using array syntax to assigning to what global points to is not
2874 // same as assigning to the global itself. {id *G;} G[i] = 0;
2875 LV.setGlobalObjCRef(false);
2876 return;
2877 }
2878
2879 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2880 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2881 // We don't know if member is an 'ivar', but this flag is looked at
2882 // only in the context of LV.isObjCIvar().
2883 LV.setObjCArray(E->getType()->isArrayType());
2884 return;
2885 }
2886 }
2887
EmitThreadPrivateVarDeclLValue(CodeGenFunction & CGF,const VarDecl * VD,QualType T,Address Addr,llvm::Type * RealVarTy,SourceLocation Loc)2888 static LValue EmitThreadPrivateVarDeclLValue(
2889 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2890 llvm::Type *RealVarTy, SourceLocation Loc) {
2891 if (CGF.CGM.getLangOpts().OpenMPIRBuilder)
2892 Addr = CodeGenFunction::OMPBuilderCBHelpers::getAddrOfThreadPrivate(
2893 CGF, VD, Addr, Loc);
2894 else
2895 Addr =
2896 CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2897
2898 Addr = Addr.withElementType(RealVarTy);
2899 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2900 }
2901
emitDeclTargetVarDeclLValue(CodeGenFunction & CGF,const VarDecl * VD,QualType T)2902 static Address emitDeclTargetVarDeclLValue(CodeGenFunction &CGF,
2903 const VarDecl *VD, QualType T) {
2904 std::optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2905 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2906 // Return an invalid address if variable is MT_To (or MT_Enter starting with
2907 // OpenMP 5.2) and unified memory is not enabled. For all other cases: MT_Link
2908 // and MT_To (or MT_Enter) with unified memory, return a valid address.
2909 if (!Res || ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
2910 *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
2911 !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory()))
2912 return Address::invalid();
2913 assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2914 ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
2915 *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
2916 CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) &&
2917 "Expected link clause OR to clause with unified memory enabled.");
2918 QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2919 Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2920 return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2921 }
2922
2923 Address
EmitLoadOfReference(LValue RefLVal,LValueBaseInfo * PointeeBaseInfo,TBAAAccessInfo * PointeeTBAAInfo)2924 CodeGenFunction::EmitLoadOfReference(LValue RefLVal,
2925 LValueBaseInfo *PointeeBaseInfo,
2926 TBAAAccessInfo *PointeeTBAAInfo) {
2927 llvm::LoadInst *Load =
2928 Builder.CreateLoad(RefLVal.getAddress(), RefLVal.isVolatile());
2929 CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2930 QualType PTy = RefLVal.getType()->getPointeeType();
2931 CharUnits Align = CGM.getNaturalTypeAlignment(
2932 PTy, PointeeBaseInfo, PointeeTBAAInfo, /*ForPointeeType=*/true);
2933 if (!PTy->isIncompleteType()) {
2934 llvm::LLVMContext &Ctx = getLLVMContext();
2935 llvm::MDBuilder MDB(Ctx);
2936 // Emit !nonnull metadata
2937 if (CGM.getTypes().getTargetAddressSpace(PTy) == 0 &&
2938 !CGM.getCodeGenOpts().NullPointerIsValid)
2939 Load->setMetadata(llvm::LLVMContext::MD_nonnull,
2940 llvm::MDNode::get(Ctx, {}));
2941 // Emit !align metadata
2942 if (PTy->isObjectType()) {
2943 auto AlignVal = Align.getQuantity();
2944 if (AlignVal > 1) {
2945 Load->setMetadata(
2946 llvm::LLVMContext::MD_align,
2947 llvm::MDNode::get(Ctx, MDB.createConstant(llvm::ConstantInt::get(
2948 Builder.getInt64Ty(), AlignVal))));
2949 }
2950 }
2951 }
2952 return makeNaturalAddressForPointer(Load, PTy, Align,
2953 /*ForPointeeType=*/true, PointeeBaseInfo,
2954 PointeeTBAAInfo);
2955 }
2956
EmitLoadOfReferenceLValue(LValue RefLVal)2957 LValue CodeGenFunction::EmitLoadOfReferenceLValue(LValue RefLVal) {
2958 LValueBaseInfo PointeeBaseInfo;
2959 TBAAAccessInfo PointeeTBAAInfo;
2960 Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2961 &PointeeTBAAInfo);
2962 return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2963 PointeeBaseInfo, PointeeTBAAInfo);
2964 }
2965
EmitLoadOfPointer(Address Ptr,const PointerType * PtrTy,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo)2966 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2967 const PointerType *PtrTy,
2968 LValueBaseInfo *BaseInfo,
2969 TBAAAccessInfo *TBAAInfo) {
2970 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2971 return makeNaturalAddressForPointer(Addr, PtrTy->getPointeeType(),
2972 CharUnits(), /*ForPointeeType=*/true,
2973 BaseInfo, TBAAInfo);
2974 }
2975
EmitLoadOfPointerLValue(Address PtrAddr,const PointerType * PtrTy)2976 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2977 const PointerType *PtrTy) {
2978 LValueBaseInfo BaseInfo;
2979 TBAAAccessInfo TBAAInfo;
2980 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2981 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2982 }
2983
EmitGlobalVarDeclLValue(CodeGenFunction & CGF,const Expr * E,const VarDecl * VD)2984 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2985 const Expr *E, const VarDecl *VD) {
2986 QualType T = E->getType();
2987
2988 // If it's thread_local, emit a call to its wrapper function instead.
2989 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2990 CGF.CGM.getCXXABI().usesThreadWrapperFunction(VD))
2991 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2992 // Check if the variable is marked as declare target with link clause in
2993 // device codegen.
2994 if (CGF.getLangOpts().OpenMPIsTargetDevice) {
2995 Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2996 if (Addr.isValid())
2997 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2998 }
2999
3000 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
3001
3002 if (VD->getTLSKind() != VarDecl::TLS_None)
3003 V = CGF.Builder.CreateThreadLocalAddress(V);
3004
3005 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
3006 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
3007 Address Addr(V, RealVarTy, Alignment);
3008 // Emit reference to the private copy of the variable if it is an OpenMP
3009 // threadprivate variable.
3010 if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
3011 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
3012 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
3013 E->getExprLoc());
3014 }
3015 LValue LV = VD->getType()->isReferenceType() ?
3016 CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
3017 AlignmentSource::Decl) :
3018 CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
3019 setObjCGCLValueClass(CGF.getContext(), E, LV);
3020 return LV;
3021 }
3022
getRawFunctionPointer(GlobalDecl GD,llvm::Type * Ty)3023 llvm::Constant *CodeGenModule::getRawFunctionPointer(GlobalDecl GD,
3024 llvm::Type *Ty) {
3025 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
3026 if (FD->hasAttr<WeakRefAttr>()) {
3027 ConstantAddress aliasee = GetWeakRefReference(FD);
3028 return aliasee.getPointer();
3029 }
3030
3031 llvm::Constant *V = GetAddrOfFunction(GD, Ty);
3032 return V;
3033 }
3034
EmitFunctionDeclLValue(CodeGenFunction & CGF,const Expr * E,GlobalDecl GD)3035 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF, const Expr *E,
3036 GlobalDecl GD) {
3037 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
3038 llvm::Constant *V = CGF.CGM.getFunctionPointer(GD);
3039 QualType ETy = E->getType();
3040 if (ETy->isCFIUncheckedCalleeFunctionType()) {
3041 if (auto *GV = dyn_cast<llvm::GlobalValue>(V))
3042 V = llvm::NoCFIValue::get(GV);
3043 }
3044 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
3045 return CGF.MakeAddrLValue(V, ETy, Alignment, AlignmentSource::Decl);
3046 }
3047
EmitCapturedFieldLValue(CodeGenFunction & CGF,const FieldDecl * FD,llvm::Value * ThisValue)3048 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
3049 llvm::Value *ThisValue) {
3050
3051 return CGF.EmitLValueForLambdaField(FD, ThisValue);
3052 }
3053
3054 /// Named Registers are named metadata pointing to the register name
3055 /// which will be read from/written to as an argument to the intrinsic
3056 /// @llvm.read/write_register.
3057 /// So far, only the name is being passed down, but other options such as
3058 /// register type, allocation type or even optimization options could be
3059 /// passed down via the metadata node.
EmitGlobalNamedRegister(const VarDecl * VD,CodeGenModule & CGM)3060 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
3061 SmallString<64> Name("llvm.named.register.");
3062 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
3063 assert(Asm->getLabel().size() < 64-Name.size() &&
3064 "Register name too big");
3065 Name.append(Asm->getLabel());
3066 llvm::NamedMDNode *M =
3067 CGM.getModule().getOrInsertNamedMetadata(Name);
3068 if (M->getNumOperands() == 0) {
3069 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
3070 Asm->getLabel());
3071 llvm::Metadata *Ops[] = {Str};
3072 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
3073 }
3074
3075 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
3076
3077 llvm::Value *Ptr =
3078 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
3079 return LValue::MakeGlobalReg(Ptr, Alignment, VD->getType());
3080 }
3081
3082 /// Determine whether we can emit a reference to \p VD from the current
3083 /// context, despite not necessarily having seen an odr-use of the variable in
3084 /// this context.
canEmitSpuriousReferenceToVariable(CodeGenFunction & CGF,const DeclRefExpr * E,const VarDecl * VD)3085 static bool canEmitSpuriousReferenceToVariable(CodeGenFunction &CGF,
3086 const DeclRefExpr *E,
3087 const VarDecl *VD) {
3088 // For a variable declared in an enclosing scope, do not emit a spurious
3089 // reference even if we have a capture, as that will emit an unwarranted
3090 // reference to our capture state, and will likely generate worse code than
3091 // emitting a local copy.
3092 if (E->refersToEnclosingVariableOrCapture())
3093 return false;
3094
3095 // For a local declaration declared in this function, we can always reference
3096 // it even if we don't have an odr-use.
3097 if (VD->hasLocalStorage()) {
3098 return VD->getDeclContext() ==
3099 dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
3100 }
3101
3102 // For a global declaration, we can emit a reference to it if we know
3103 // for sure that we are able to emit a definition of it.
3104 VD = VD->getDefinition(CGF.getContext());
3105 if (!VD)
3106 return false;
3107
3108 // Don't emit a spurious reference if it might be to a variable that only
3109 // exists on a different device / target.
3110 // FIXME: This is unnecessarily broad. Check whether this would actually be a
3111 // cross-target reference.
3112 if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
3113 CGF.getLangOpts().OpenCL) {
3114 return false;
3115 }
3116
3117 // We can emit a spurious reference only if the linkage implies that we'll
3118 // be emitting a non-interposable symbol that will be retained until link
3119 // time.
3120 switch (CGF.CGM.getLLVMLinkageVarDefinition(VD)) {
3121 case llvm::GlobalValue::ExternalLinkage:
3122 case llvm::GlobalValue::LinkOnceODRLinkage:
3123 case llvm::GlobalValue::WeakODRLinkage:
3124 case llvm::GlobalValue::InternalLinkage:
3125 case llvm::GlobalValue::PrivateLinkage:
3126 return true;
3127 default:
3128 return false;
3129 }
3130 }
3131
EmitDeclRefLValue(const DeclRefExpr * E)3132 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
3133 const NamedDecl *ND = E->getDecl();
3134 QualType T = E->getType();
3135
3136 assert(E->isNonOdrUse() != NOUR_Unevaluated &&
3137 "should not emit an unevaluated operand");
3138
3139 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
3140 // Global Named registers access via intrinsics only
3141 if (VD->getStorageClass() == SC_Register &&
3142 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
3143 return EmitGlobalNamedRegister(VD, CGM);
3144
3145 // If this DeclRefExpr does not constitute an odr-use of the variable,
3146 // we're not permitted to emit a reference to it in general, and it might
3147 // not be captured if capture would be necessary for a use. Emit the
3148 // constant value directly instead.
3149 if (E->isNonOdrUse() == NOUR_Constant &&
3150 (VD->getType()->isReferenceType() ||
3151 !canEmitSpuriousReferenceToVariable(*this, E, VD))) {
3152 VD->getAnyInitializer(VD);
3153 llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
3154 E->getLocation(), *VD->evaluateValue(), VD->getType());
3155 assert(Val && "failed to emit constant expression");
3156
3157 Address Addr = Address::invalid();
3158 if (!VD->getType()->isReferenceType()) {
3159 // Spill the constant value to a global.
3160 Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
3161 getContext().getDeclAlign(VD));
3162 llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
3163 auto *PTy = llvm::PointerType::get(
3164 getLLVMContext(), getTypes().getTargetAddressSpace(VD->getType()));
3165 Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy, VarTy);
3166 } else {
3167 // Should we be using the alignment of the constant pointer we emitted?
3168 CharUnits Alignment =
3169 CGM.getNaturalTypeAlignment(E->getType(),
3170 /* BaseInfo= */ nullptr,
3171 /* TBAAInfo= */ nullptr,
3172 /* forPointeeType= */ true);
3173 Addr = makeNaturalAddressForPointer(Val, T, Alignment);
3174 }
3175 return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
3176 }
3177
3178 // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
3179
3180 // Check for captured variables.
3181 if (E->refersToEnclosingVariableOrCapture()) {
3182 VD = VD->getCanonicalDecl();
3183 if (auto *FD = LambdaCaptureFields.lookup(VD))
3184 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
3185 if (CapturedStmtInfo) {
3186 auto I = LocalDeclMap.find(VD);
3187 if (I != LocalDeclMap.end()) {
3188 LValue CapLVal;
3189 if (VD->getType()->isReferenceType())
3190 CapLVal = EmitLoadOfReferenceLValue(I->second, VD->getType(),
3191 AlignmentSource::Decl);
3192 else
3193 CapLVal = MakeAddrLValue(I->second, T);
3194 // Mark lvalue as nontemporal if the variable is marked as nontemporal
3195 // in simd context.
3196 if (getLangOpts().OpenMP &&
3197 CGM.getOpenMPRuntime().isNontemporalDecl(VD))
3198 CapLVal.setNontemporal(/*Value=*/true);
3199 return CapLVal;
3200 }
3201 LValue CapLVal =
3202 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
3203 CapturedStmtInfo->getContextValue());
3204 Address LValueAddress = CapLVal.getAddress();
3205 CapLVal = MakeAddrLValue(Address(LValueAddress.emitRawPointer(*this),
3206 LValueAddress.getElementType(),
3207 getContext().getDeclAlign(VD)),
3208 CapLVal.getType(),
3209 LValueBaseInfo(AlignmentSource::Decl),
3210 CapLVal.getTBAAInfo());
3211 // Mark lvalue as nontemporal if the variable is marked as nontemporal
3212 // in simd context.
3213 if (getLangOpts().OpenMP &&
3214 CGM.getOpenMPRuntime().isNontemporalDecl(VD))
3215 CapLVal.setNontemporal(/*Value=*/true);
3216 return CapLVal;
3217 }
3218
3219 assert(isa<BlockDecl>(CurCodeDecl));
3220 Address addr = GetAddrOfBlockDecl(VD);
3221 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
3222 }
3223 }
3224
3225 // FIXME: We should be able to assert this for FunctionDecls as well!
3226 // FIXME: We should be able to assert this for all DeclRefExprs, not just
3227 // those with a valid source location.
3228 assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
3229 !E->getLocation().isValid()) &&
3230 "Should not use decl without marking it used!");
3231
3232 if (ND->hasAttr<WeakRefAttr>()) {
3233 const auto *VD = cast<ValueDecl>(ND);
3234 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
3235 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
3236 }
3237
3238 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
3239 // Check if this is a global variable.
3240 if (VD->hasLinkage() || VD->isStaticDataMember())
3241 return EmitGlobalVarDeclLValue(*this, E, VD);
3242
3243 Address addr = Address::invalid();
3244
3245 // The variable should generally be present in the local decl map.
3246 auto iter = LocalDeclMap.find(VD);
3247 if (iter != LocalDeclMap.end()) {
3248 addr = iter->second;
3249
3250 // Otherwise, it might be static local we haven't emitted yet for
3251 // some reason; most likely, because it's in an outer function.
3252 } else if (VD->isStaticLocal()) {
3253 llvm::Constant *var = CGM.getOrCreateStaticVarDecl(
3254 *VD, CGM.getLLVMLinkageVarDefinition(VD));
3255 addr = Address(
3256 var, ConvertTypeForMem(VD->getType()), getContext().getDeclAlign(VD));
3257
3258 // No other cases for now.
3259 } else {
3260 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
3261 }
3262
3263 // Handle threadlocal function locals.
3264 if (VD->getTLSKind() != VarDecl::TLS_None)
3265 addr = addr.withPointer(
3266 Builder.CreateThreadLocalAddress(addr.getBasePointer()),
3267 NotKnownNonNull);
3268
3269 // Check for OpenMP threadprivate variables.
3270 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
3271 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
3272 return EmitThreadPrivateVarDeclLValue(
3273 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
3274 E->getExprLoc());
3275 }
3276
3277 // Drill into block byref variables.
3278 bool isBlockByref = VD->isEscapingByref();
3279 if (isBlockByref) {
3280 addr = emitBlockByrefAddress(addr, VD);
3281 }
3282
3283 // Drill into reference types.
3284 LValue LV = VD->getType()->isReferenceType() ?
3285 EmitLoadOfReferenceLValue(addr, VD->getType(), AlignmentSource::Decl) :
3286 MakeAddrLValue(addr, T, AlignmentSource::Decl);
3287
3288 bool isLocalStorage = VD->hasLocalStorage();
3289
3290 bool NonGCable = isLocalStorage &&
3291 !VD->getType()->isReferenceType() &&
3292 !isBlockByref;
3293 if (NonGCable) {
3294 LV.getQuals().removeObjCGCAttr();
3295 LV.setNonGC(true);
3296 }
3297
3298 bool isImpreciseLifetime =
3299 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
3300 if (isImpreciseLifetime)
3301 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
3302 setObjCGCLValueClass(getContext(), E, LV);
3303 return LV;
3304 }
3305
3306 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
3307 return EmitFunctionDeclLValue(*this, E, FD);
3308
3309 // FIXME: While we're emitting a binding from an enclosing scope, all other
3310 // DeclRefExprs we see should be implicitly treated as if they also refer to
3311 // an enclosing scope.
3312 if (const auto *BD = dyn_cast<BindingDecl>(ND)) {
3313 if (E->refersToEnclosingVariableOrCapture()) {
3314 auto *FD = LambdaCaptureFields.lookup(BD);
3315 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
3316 }
3317 // Suppress debug location updates when visiting the binding, since the
3318 // binding may emit instructions that would otherwise be associated with the
3319 // binding itself, rather than the expression referencing the binding. (this
3320 // leads to jumpy debug stepping behavior where the location/debugger jump
3321 // back to the binding declaration, then back to the expression referencing
3322 // the binding)
3323 DisableDebugLocationUpdates D(*this);
3324 return EmitLValue(BD->getBinding(), NotKnownNonNull);
3325 }
3326
3327 // We can form DeclRefExprs naming GUID declarations when reconstituting
3328 // non-type template parameters into expressions.
3329 if (const auto *GD = dyn_cast<MSGuidDecl>(ND))
3330 return MakeAddrLValue(CGM.GetAddrOfMSGuidDecl(GD), T,
3331 AlignmentSource::Decl);
3332
3333 if (const auto *TPO = dyn_cast<TemplateParamObjectDecl>(ND)) {
3334 auto ATPO = CGM.GetAddrOfTemplateParamObject(TPO);
3335 auto AS = getLangASFromTargetAS(ATPO.getAddressSpace());
3336
3337 if (AS != T.getAddressSpace()) {
3338 auto TargetAS = getContext().getTargetAddressSpace(T.getAddressSpace());
3339 auto PtrTy = llvm::PointerType::get(CGM.getLLVMContext(), TargetAS);
3340 auto ASC = getTargetHooks().performAddrSpaceCast(CGM, ATPO.getPointer(),
3341 AS, PtrTy);
3342 ATPO = ConstantAddress(ASC, ATPO.getElementType(), ATPO.getAlignment());
3343 }
3344
3345 return MakeAddrLValue(ATPO, T, AlignmentSource::Decl);
3346 }
3347
3348 llvm_unreachable("Unhandled DeclRefExpr");
3349 }
3350
EmitUnaryOpLValue(const UnaryOperator * E)3351 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
3352 // __extension__ doesn't affect lvalue-ness.
3353 if (E->getOpcode() == UO_Extension)
3354 return EmitLValue(E->getSubExpr());
3355
3356 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
3357 switch (E->getOpcode()) {
3358 default: llvm_unreachable("Unknown unary operator lvalue!");
3359 case UO_Deref: {
3360 QualType T = E->getSubExpr()->getType()->getPointeeType();
3361 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
3362
3363 LValueBaseInfo BaseInfo;
3364 TBAAAccessInfo TBAAInfo;
3365 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
3366 &TBAAInfo);
3367 LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
3368 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
3369
3370 // We should not generate __weak write barrier on indirect reference
3371 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
3372 // But, we continue to generate __strong write barrier on indirect write
3373 // into a pointer to object.
3374 if (getLangOpts().ObjC &&
3375 getLangOpts().getGC() != LangOptions::NonGC &&
3376 LV.isObjCWeak())
3377 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3378 return LV;
3379 }
3380 case UO_Real:
3381 case UO_Imag: {
3382 LValue LV = EmitLValue(E->getSubExpr());
3383 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
3384
3385 // __real is valid on scalars. This is a faster way of testing that.
3386 // __imag can only produce an rvalue on scalars.
3387 if (E->getOpcode() == UO_Real &&
3388 !LV.getAddress().getElementType()->isStructTy()) {
3389 assert(E->getSubExpr()->getType()->isArithmeticType());
3390 return LV;
3391 }
3392
3393 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
3394
3395 Address Component =
3396 (E->getOpcode() == UO_Real
3397 ? emitAddrOfRealComponent(LV.getAddress(), LV.getType())
3398 : emitAddrOfImagComponent(LV.getAddress(), LV.getType()));
3399 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
3400 CGM.getTBAAInfoForSubobject(LV, T));
3401 ElemLV.getQuals().addQualifiers(LV.getQuals());
3402 return ElemLV;
3403 }
3404 case UO_PreInc:
3405 case UO_PreDec: {
3406 LValue LV = EmitLValue(E->getSubExpr());
3407 bool isInc = E->getOpcode() == UO_PreInc;
3408
3409 if (E->getType()->isAnyComplexType())
3410 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
3411 else
3412 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
3413 return LV;
3414 }
3415 }
3416 }
3417
EmitStringLiteralLValue(const StringLiteral * E)3418 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
3419 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
3420 E->getType(), AlignmentSource::Decl);
3421 }
3422
EmitObjCEncodeExprLValue(const ObjCEncodeExpr * E)3423 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
3424 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
3425 E->getType(), AlignmentSource::Decl);
3426 }
3427
EmitPredefinedLValue(const PredefinedExpr * E)3428 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
3429 auto SL = E->getFunctionName();
3430 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
3431 StringRef FnName = CurFn->getName();
3432 FnName.consume_front("\01");
3433 StringRef NameItems[] = {
3434 PredefinedExpr::getIdentKindName(E->getIdentKind()), FnName};
3435 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
3436 if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
3437 std::string Name = std::string(SL->getString());
3438 if (!Name.empty()) {
3439 unsigned Discriminator =
3440 CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
3441 if (Discriminator)
3442 Name += "_" + Twine(Discriminator + 1).str();
3443 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
3444 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
3445 } else {
3446 auto C =
3447 CGM.GetAddrOfConstantCString(std::string(FnName), GVName.c_str());
3448 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
3449 }
3450 }
3451 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
3452 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
3453 }
3454
3455 /// Emit a type description suitable for use by a runtime sanitizer library. The
3456 /// format of a type descriptor is
3457 ///
3458 /// \code
3459 /// { i16 TypeKind, i16 TypeInfo }
3460 /// \endcode
3461 ///
3462 /// followed by an array of i8 containing the type name with extra information
3463 /// for BitInt. TypeKind is TK_Integer(0) for an integer, TK_Float(1) for a
3464 /// floating point value, TK_BitInt(2) for BitInt and TK_Unknown(0xFFFF) for
3465 /// anything else.
EmitCheckTypeDescriptor(QualType T)3466 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
3467 // Only emit each type's descriptor once.
3468 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
3469 return C;
3470
3471 uint16_t TypeKind = TK_Unknown;
3472 uint16_t TypeInfo = 0;
3473 bool IsBitInt = false;
3474
3475 if (T->isIntegerType()) {
3476 TypeKind = TK_Integer;
3477 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
3478 (T->isSignedIntegerType() ? 1 : 0);
3479 // Follow suggestion from discussion of issue 64100.
3480 // So we can write the exact amount of bits in TypeName after '\0'
3481 // making it <diagnostic-like type name>.'\0'.<32-bit width>.
3482 if (T->isSignedIntegerType() && T->getAs<BitIntType>()) {
3483 // Do a sanity checks as we are using 32-bit type to store bit length.
3484 assert(getContext().getTypeSize(T) > 0 &&
3485 " non positive amount of bits in __BitInt type");
3486 assert(getContext().getTypeSize(T) <= 0xFFFFFFFF &&
3487 " too many bits in __BitInt type");
3488
3489 // Redefine TypeKind with the actual __BitInt type if we have signed
3490 // BitInt.
3491 TypeKind = TK_BitInt;
3492 IsBitInt = true;
3493 }
3494 } else if (T->isFloatingType()) {
3495 TypeKind = TK_Float;
3496 TypeInfo = getContext().getTypeSize(T);
3497 }
3498
3499 // Format the type name as if for a diagnostic, including quotes and
3500 // optionally an 'aka'.
3501 SmallString<32> Buffer;
3502 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype,
3503 (intptr_t)T.getAsOpaquePtr(), StringRef(),
3504 StringRef(), {}, Buffer, {});
3505
3506 if (IsBitInt) {
3507 // The Structure is: 0 to end the string, 32 bit unsigned integer in target
3508 // endianness, zero.
3509 char S[6] = {'\0', '\0', '\0', '\0', '\0', '\0'};
3510 const auto *EIT = T->castAs<BitIntType>();
3511 uint32_t Bits = EIT->getNumBits();
3512 llvm::support::endian::write32(S + 1, Bits,
3513 getTarget().isBigEndian()
3514 ? llvm::endianness::big
3515 : llvm::endianness::little);
3516 StringRef Str = StringRef(S, sizeof(S) / sizeof(decltype(S[0])));
3517 Buffer.append(Str);
3518 }
3519
3520 llvm::Constant *Components[] = {
3521 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
3522 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
3523 };
3524 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
3525
3526 auto *GV = new llvm::GlobalVariable(
3527 CGM.getModule(), Descriptor->getType(),
3528 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
3529 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3530 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
3531
3532 // Remember the descriptor for this type.
3533 CGM.setTypeDescriptorInMap(T, GV);
3534
3535 return GV;
3536 }
3537
EmitCheckValue(llvm::Value * V)3538 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
3539 llvm::Type *TargetTy = IntPtrTy;
3540
3541 if (V->getType() == TargetTy)
3542 return V;
3543
3544 // Floating-point types which fit into intptr_t are bitcast to integers
3545 // and then passed directly (after zero-extension, if necessary).
3546 if (V->getType()->isFloatingPointTy()) {
3547 unsigned Bits = V->getType()->getPrimitiveSizeInBits().getFixedValue();
3548 if (Bits <= TargetTy->getIntegerBitWidth())
3549 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
3550 Bits));
3551 }
3552
3553 // Integers which fit in intptr_t are zero-extended and passed directly.
3554 if (V->getType()->isIntegerTy() &&
3555 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
3556 return Builder.CreateZExt(V, TargetTy);
3557
3558 // Pointers are passed directly, everything else is passed by address.
3559 if (!V->getType()->isPointerTy()) {
3560 RawAddress Ptr = CreateDefaultAlignTempAlloca(V->getType());
3561 Builder.CreateStore(V, Ptr);
3562 V = Ptr.getPointer();
3563 }
3564 return Builder.CreatePtrToInt(V, TargetTy);
3565 }
3566
3567 /// Emit a representation of a SourceLocation for passing to a handler
3568 /// in a sanitizer runtime library. The format for this data is:
3569 /// \code
3570 /// struct SourceLocation {
3571 /// const char *Filename;
3572 /// int32_t Line, Column;
3573 /// };
3574 /// \endcode
3575 /// For an invalid SourceLocation, the Filename pointer is null.
EmitCheckSourceLocation(SourceLocation Loc)3576 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
3577 llvm::Constant *Filename;
3578 int Line, Column;
3579
3580 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
3581 if (PLoc.isValid()) {
3582 StringRef FilenameString = PLoc.getFilename();
3583
3584 int PathComponentsToStrip =
3585 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
3586 if (PathComponentsToStrip < 0) {
3587 assert(PathComponentsToStrip != INT_MIN);
3588 int PathComponentsToKeep = -PathComponentsToStrip;
3589 auto I = llvm::sys::path::rbegin(FilenameString);
3590 auto E = llvm::sys::path::rend(FilenameString);
3591 while (I != E && --PathComponentsToKeep)
3592 ++I;
3593
3594 FilenameString = FilenameString.substr(I - E);
3595 } else if (PathComponentsToStrip > 0) {
3596 auto I = llvm::sys::path::begin(FilenameString);
3597 auto E = llvm::sys::path::end(FilenameString);
3598 while (I != E && PathComponentsToStrip--)
3599 ++I;
3600
3601 if (I != E)
3602 FilenameString =
3603 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
3604 else
3605 FilenameString = llvm::sys::path::filename(FilenameString);
3606 }
3607
3608 auto FilenameGV =
3609 CGM.GetAddrOfConstantCString(std::string(FilenameString), ".src");
3610 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
3611 cast<llvm::GlobalVariable>(
3612 FilenameGV.getPointer()->stripPointerCasts()));
3613 Filename = FilenameGV.getPointer();
3614 Line = PLoc.getLine();
3615 Column = PLoc.getColumn();
3616 } else {
3617 Filename = llvm::Constant::getNullValue(Int8PtrTy);
3618 Line = Column = 0;
3619 }
3620
3621 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
3622 Builder.getInt32(Column)};
3623
3624 return llvm::ConstantStruct::getAnon(Data);
3625 }
3626
3627 namespace {
3628 /// Specify under what conditions this check can be recovered
3629 enum class CheckRecoverableKind {
3630 /// Always terminate program execution if this check fails.
3631 Unrecoverable,
3632 /// Check supports recovering, runtime has both fatal (noreturn) and
3633 /// non-fatal handlers for this check.
3634 Recoverable,
3635 /// Runtime conditionally aborts, always need to support recovery.
3636 AlwaysRecoverable
3637 };
3638 }
3639
3640 static CheckRecoverableKind
getRecoverableKind(SanitizerKind::SanitizerOrdinal Ordinal)3641 getRecoverableKind(SanitizerKind::SanitizerOrdinal Ordinal) {
3642 if (Ordinal == SanitizerKind::SO_Vptr)
3643 return CheckRecoverableKind::AlwaysRecoverable;
3644 else if (Ordinal == SanitizerKind::SO_Return ||
3645 Ordinal == SanitizerKind::SO_Unreachable)
3646 return CheckRecoverableKind::Unrecoverable;
3647 else
3648 return CheckRecoverableKind::Recoverable;
3649 }
3650
3651 namespace {
3652 struct SanitizerHandlerInfo {
3653 char const *const Name;
3654 unsigned Version;
3655 };
3656 }
3657
3658 const SanitizerHandlerInfo SanitizerHandlers[] = {
3659 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
3660 LIST_SANITIZER_CHECKS
3661 #undef SANITIZER_CHECK
3662 };
3663
emitCheckHandlerCall(CodeGenFunction & CGF,llvm::FunctionType * FnType,ArrayRef<llvm::Value * > FnArgs,SanitizerHandler CheckHandler,CheckRecoverableKind RecoverKind,bool IsFatal,llvm::BasicBlock * ContBB,bool NoMerge)3664 static void emitCheckHandlerCall(CodeGenFunction &CGF,
3665 llvm::FunctionType *FnType,
3666 ArrayRef<llvm::Value *> FnArgs,
3667 SanitizerHandler CheckHandler,
3668 CheckRecoverableKind RecoverKind, bool IsFatal,
3669 llvm::BasicBlock *ContBB, bool NoMerge) {
3670 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
3671 std::optional<ApplyDebugLocation> DL;
3672 if (!CGF.Builder.getCurrentDebugLocation()) {
3673 // Ensure that the call has at least an artificial debug location.
3674 DL.emplace(CGF, SourceLocation());
3675 }
3676 bool NeedsAbortSuffix =
3677 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
3678 bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
3679 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
3680 const StringRef CheckName = CheckInfo.Name;
3681 std::string FnName = "__ubsan_handle_" + CheckName.str();
3682 if (CheckInfo.Version && !MinimalRuntime)
3683 FnName += "_v" + llvm::utostr(CheckInfo.Version);
3684 if (MinimalRuntime)
3685 FnName += "_minimal";
3686 if (NeedsAbortSuffix)
3687 FnName += "_abort";
3688 bool MayReturn =
3689 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
3690
3691 llvm::AttrBuilder B(CGF.getLLVMContext());
3692 if (!MayReturn) {
3693 B.addAttribute(llvm::Attribute::NoReturn)
3694 .addAttribute(llvm::Attribute::NoUnwind);
3695 }
3696 B.addUWTableAttr(llvm::UWTableKind::Default);
3697
3698 llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
3699 FnType, FnName,
3700 llvm::AttributeList::get(CGF.getLLVMContext(),
3701 llvm::AttributeList::FunctionIndex, B),
3702 /*Local=*/true);
3703 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
3704 NoMerge = NoMerge || !CGF.CGM.getCodeGenOpts().OptimizationLevel ||
3705 (CGF.CurCodeDecl && CGF.CurCodeDecl->hasAttr<OptimizeNoneAttr>());
3706 if (NoMerge)
3707 HandlerCall->addFnAttr(llvm::Attribute::NoMerge);
3708 if (!MayReturn) {
3709 HandlerCall->setDoesNotReturn();
3710 CGF.Builder.CreateUnreachable();
3711 } else {
3712 CGF.Builder.CreateBr(ContBB);
3713 }
3714 }
3715
EmitCheck(ArrayRef<std::pair<llvm::Value *,SanitizerKind::SanitizerOrdinal>> Checked,SanitizerHandler CheckHandler,ArrayRef<llvm::Constant * > StaticArgs,ArrayRef<llvm::Value * > DynamicArgs)3716 void CodeGenFunction::EmitCheck(
3717 ArrayRef<std::pair<llvm::Value *, SanitizerKind::SanitizerOrdinal>> Checked,
3718 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3719 ArrayRef<llvm::Value *> DynamicArgs) {
3720 assert(IsSanitizerScope);
3721 assert(Checked.size() > 0);
3722 assert(CheckHandler >= 0 &&
3723 size_t(CheckHandler) < std::size(SanitizerHandlers));
3724 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3725
3726 llvm::Value *FatalCond = nullptr;
3727 llvm::Value *RecoverableCond = nullptr;
3728 llvm::Value *TrapCond = nullptr;
3729 bool NoMerge = false;
3730 // Expand checks into:
3731 // (Check1 || !allow_ubsan_check) && (Check2 || !allow_ubsan_check) ...
3732 // We need separate allow_ubsan_check intrinsics because they have separately
3733 // specified cutoffs.
3734 // This expression looks expensive but will be simplified after
3735 // LowerAllowCheckPass.
3736 for (auto &[Check, Ord] : Checked) {
3737 llvm::Value *GuardedCheck = Check;
3738 if (ClSanitizeGuardChecks ||
3739 (CGM.getCodeGenOpts().SanitizeSkipHotCutoffs[Ord] > 0)) {
3740 llvm::Value *Allow = Builder.CreateCall(
3741 CGM.getIntrinsic(llvm::Intrinsic::allow_ubsan_check),
3742 llvm::ConstantInt::get(CGM.Int8Ty, Ord));
3743 GuardedCheck = Builder.CreateOr(Check, Builder.CreateNot(Allow));
3744 }
3745
3746 // -fsanitize-trap= overrides -fsanitize-recover=.
3747 llvm::Value *&Cond = CGM.getCodeGenOpts().SanitizeTrap.has(Ord) ? TrapCond
3748 : CGM.getCodeGenOpts().SanitizeRecover.has(Ord)
3749 ? RecoverableCond
3750 : FatalCond;
3751 Cond = Cond ? Builder.CreateAnd(Cond, GuardedCheck) : GuardedCheck;
3752
3753 if (!CGM.getCodeGenOpts().SanitizeMergeHandlers.has(Ord))
3754 NoMerge = true;
3755 }
3756
3757 if (TrapCond)
3758 EmitTrapCheck(TrapCond, CheckHandler, NoMerge);
3759 if (!FatalCond && !RecoverableCond)
3760 return;
3761
3762 llvm::Value *JointCond;
3763 if (FatalCond && RecoverableCond)
3764 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3765 else
3766 JointCond = FatalCond ? FatalCond : RecoverableCond;
3767 assert(JointCond);
3768
3769 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3770 assert(SanOpts.has(Checked[0].second));
3771 #ifndef NDEBUG
3772 for (int i = 1, n = Checked.size(); i < n; ++i) {
3773 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3774 "All recoverable kinds in a single check must be same!");
3775 assert(SanOpts.has(Checked[i].second));
3776 }
3777 #endif
3778
3779 llvm::BasicBlock *Cont = createBasicBlock("cont");
3780 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3781 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3782 // Give hint that we very much don't expect to execute the handler
3783 llvm::MDBuilder MDHelper(getLLVMContext());
3784 llvm::MDNode *Node = MDHelper.createLikelyBranchWeights();
3785 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3786 EmitBlock(Handlers);
3787
3788 // Handler functions take an i8* pointing to the (handler-specific) static
3789 // information block, followed by a sequence of intptr_t arguments
3790 // representing operand values.
3791 SmallVector<llvm::Value *, 4> Args;
3792 SmallVector<llvm::Type *, 4> ArgTypes;
3793 if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3794 Args.reserve(DynamicArgs.size() + 1);
3795 ArgTypes.reserve(DynamicArgs.size() + 1);
3796
3797 // Emit handler arguments and create handler function type.
3798 if (!StaticArgs.empty()) {
3799 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3800 auto *InfoPtr = new llvm::GlobalVariable(
3801 CGM.getModule(), Info->getType(), false,
3802 llvm::GlobalVariable::PrivateLinkage, Info, "", nullptr,
3803 llvm::GlobalVariable::NotThreadLocal,
3804 CGM.getDataLayout().getDefaultGlobalsAddressSpace());
3805 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3806 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3807 Args.push_back(InfoPtr);
3808 ArgTypes.push_back(Args.back()->getType());
3809 }
3810
3811 for (llvm::Value *DynamicArg : DynamicArgs) {
3812 Args.push_back(EmitCheckValue(DynamicArg));
3813 ArgTypes.push_back(IntPtrTy);
3814 }
3815 }
3816
3817 llvm::FunctionType *FnType =
3818 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3819
3820 if (!FatalCond || !RecoverableCond) {
3821 // Simple case: we need to generate a single handler call, either
3822 // fatal, or non-fatal.
3823 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3824 (FatalCond != nullptr), Cont, NoMerge);
3825 } else {
3826 // Emit two handler calls: first one for set of unrecoverable checks,
3827 // another one for recoverable.
3828 llvm::BasicBlock *NonFatalHandlerBB =
3829 createBasicBlock("non_fatal." + CheckName);
3830 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3831 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3832 EmitBlock(FatalHandlerBB);
3833 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3834 NonFatalHandlerBB, NoMerge);
3835 EmitBlock(NonFatalHandlerBB);
3836 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3837 Cont, NoMerge);
3838 }
3839
3840 EmitBlock(Cont);
3841 }
3842
EmitCfiSlowPathCheck(SanitizerKind::SanitizerOrdinal Ordinal,llvm::Value * Cond,llvm::ConstantInt * TypeId,llvm::Value * Ptr,ArrayRef<llvm::Constant * > StaticArgs)3843 void CodeGenFunction::EmitCfiSlowPathCheck(
3844 SanitizerKind::SanitizerOrdinal Ordinal, llvm::Value *Cond,
3845 llvm::ConstantInt *TypeId, llvm::Value *Ptr,
3846 ArrayRef<llvm::Constant *> StaticArgs) {
3847 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3848
3849 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3850 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3851
3852 llvm::MDBuilder MDHelper(getLLVMContext());
3853 llvm::MDNode *Node = MDHelper.createLikelyBranchWeights();
3854 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3855
3856 EmitBlock(CheckBB);
3857
3858 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Ordinal);
3859
3860 llvm::CallInst *CheckCall;
3861 llvm::FunctionCallee SlowPathFn;
3862 if (WithDiag) {
3863 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3864 auto *InfoPtr =
3865 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3866 llvm::GlobalVariable::PrivateLinkage, Info);
3867 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3868 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3869
3870 SlowPathFn = CGM.getModule().getOrInsertFunction(
3871 "__cfi_slowpath_diag",
3872 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3873 false));
3874 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr, InfoPtr});
3875 } else {
3876 SlowPathFn = CGM.getModule().getOrInsertFunction(
3877 "__cfi_slowpath",
3878 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3879 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3880 }
3881
3882 CGM.setDSOLocal(
3883 cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3884 CheckCall->setDoesNotThrow();
3885
3886 EmitBlock(Cont);
3887 }
3888
3889 // Emit a stub for __cfi_check function so that the linker knows about this
3890 // symbol in LTO mode.
EmitCfiCheckStub()3891 void CodeGenFunction::EmitCfiCheckStub() {
3892 llvm::Module *M = &CGM.getModule();
3893 ASTContext &C = getContext();
3894 QualType QInt64Ty = C.getIntTypeForBitwidth(64, false);
3895
3896 FunctionArgList FnArgs;
3897 ImplicitParamDecl ArgCallsiteTypeId(C, QInt64Ty, ImplicitParamKind::Other);
3898 ImplicitParamDecl ArgAddr(C, C.VoidPtrTy, ImplicitParamKind::Other);
3899 ImplicitParamDecl ArgCFICheckFailData(C, C.VoidPtrTy,
3900 ImplicitParamKind::Other);
3901 FnArgs.push_back(&ArgCallsiteTypeId);
3902 FnArgs.push_back(&ArgAddr);
3903 FnArgs.push_back(&ArgCFICheckFailData);
3904 const CGFunctionInfo &FI =
3905 CGM.getTypes().arrangeBuiltinFunctionDeclaration(C.VoidTy, FnArgs);
3906
3907 llvm::Function *F = llvm::Function::Create(
3908 llvm::FunctionType::get(VoidTy, {Int64Ty, VoidPtrTy, VoidPtrTy}, false),
3909 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3910 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F, /*IsThunk=*/false);
3911 CGM.SetLLVMFunctionAttributesForDefinition(nullptr, F);
3912 F->setAlignment(llvm::Align(4096));
3913 CGM.setDSOLocal(F);
3914
3915 llvm::LLVMContext &Ctx = M->getContext();
3916 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3917 // CrossDSOCFI pass is not executed if there is no executable code.
3918 SmallVector<llvm::Value*> Args{F->getArg(2), F->getArg(1)};
3919 llvm::CallInst::Create(M->getFunction("__cfi_check_fail"), Args, "", BB);
3920 llvm::ReturnInst::Create(Ctx, nullptr, BB);
3921 }
3922
3923 // This function is basically a switch over the CFI failure kind, which is
3924 // extracted from CFICheckFailData (1st function argument). Each case is either
3925 // llvm.trap or a call to one of the two runtime handlers, based on
3926 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3927 // failure kind) traps, but this should really never happen. CFICheckFailData
3928 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3929 // check kind; in this case __cfi_check_fail traps as well.
EmitCfiCheckFail()3930 void CodeGenFunction::EmitCfiCheckFail() {
3931 auto CheckHandler = SanitizerHandler::CFICheckFail;
3932 // TODO: the SanitizerKind is not yet determined for this check (and might
3933 // not even be available, if Data == nullptr). However, we still want to
3934 // annotate the instrumentation. We approximate this by using all the CFI
3935 // kinds.
3936 SanitizerDebugLocation SanScope(
3937 this,
3938 {SanitizerKind::SO_CFIVCall, SanitizerKind::SO_CFINVCall,
3939 SanitizerKind::SO_CFIDerivedCast, SanitizerKind::SO_CFIUnrelatedCast,
3940 SanitizerKind::SO_CFIICall},
3941 CheckHandler);
3942 FunctionArgList Args;
3943 ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy,
3944 ImplicitParamKind::Other);
3945 ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy,
3946 ImplicitParamKind::Other);
3947 Args.push_back(&ArgData);
3948 Args.push_back(&ArgAddr);
3949
3950 const CGFunctionInfo &FI =
3951 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
3952
3953 llvm::Function *F = llvm::Function::Create(
3954 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3955 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3956
3957 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F, /*IsThunk=*/false);
3958 CGM.SetLLVMFunctionAttributesForDefinition(nullptr, F);
3959 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3960
3961 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3962 SourceLocation());
3963
3964 // This function is not affected by NoSanitizeList. This function does
3965 // not have a source location, but "src:*" would still apply. Revert any
3966 // changes to SanOpts made in StartFunction.
3967 SanOpts = CGM.getLangOpts().Sanitize;
3968
3969 llvm::Value *Data =
3970 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3971 CGM.getContext().VoidPtrTy, ArgData.getLocation());
3972 llvm::Value *Addr =
3973 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3974 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3975
3976 // Data == nullptr means the calling module has trap behaviour for this check.
3977 llvm::Value *DataIsNotNullPtr =
3978 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3979 // TODO: since there is no data, we don't know the CheckKind, and therefore
3980 // cannot inspect CGM.getCodeGenOpts().SanitizeMergeHandlers. We default to
3981 // NoMerge = false. Users can disable merging by disabling optimization.
3982 EmitTrapCheck(DataIsNotNullPtr, SanitizerHandler::CFICheckFail,
3983 /*NoMerge=*/false);
3984
3985 llvm::StructType *SourceLocationTy =
3986 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3987 llvm::StructType *CfiCheckFailDataTy =
3988 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3989
3990 llvm::Value *V = Builder.CreateConstGEP2_32(
3991 CfiCheckFailDataTy, Builder.CreatePointerCast(Data, UnqualPtrTy), 0, 0);
3992
3993 Address CheckKindAddr(V, Int8Ty, getIntAlign());
3994 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3995
3996 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3997 CGM.getLLVMContext(),
3998 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3999 llvm::Value *ValidVtable = Builder.CreateZExt(
4000 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
4001 {Addr, AllVtables}),
4002 IntPtrTy);
4003
4004 const std::pair<int, SanitizerKind::SanitizerOrdinal> CheckKinds[] = {
4005 {CFITCK_VCall, SanitizerKind::SO_CFIVCall},
4006 {CFITCK_NVCall, SanitizerKind::SO_CFINVCall},
4007 {CFITCK_DerivedCast, SanitizerKind::SO_CFIDerivedCast},
4008 {CFITCK_UnrelatedCast, SanitizerKind::SO_CFIUnrelatedCast},
4009 {CFITCK_ICall, SanitizerKind::SO_CFIICall}};
4010
4011 for (auto CheckKindOrdinalPair : CheckKinds) {
4012 int Kind = CheckKindOrdinalPair.first;
4013 SanitizerKind::SanitizerOrdinal Ordinal = CheckKindOrdinalPair.second;
4014
4015 // TODO: we could apply SanitizerAnnotateDebugInfo(Ordinal) instead of
4016 // relying on the SanitizerScope with all CFI ordinals
4017
4018 llvm::Value *Cond =
4019 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
4020 if (CGM.getLangOpts().Sanitize.has(Ordinal))
4021 EmitCheck(std::make_pair(Cond, Ordinal), SanitizerHandler::CFICheckFail,
4022 {}, {Data, Addr, ValidVtable});
4023 else
4024 // TODO: we can't rely on CGM.getCodeGenOpts().SanitizeMergeHandlers.
4025 // Although the compiler allows SanitizeMergeHandlers to be set
4026 // independently of CGM.getLangOpts().Sanitize, Driver/SanitizerArgs.cpp
4027 // requires that SanitizeMergeHandlers is a subset of Sanitize.
4028 EmitTrapCheck(Cond, CheckHandler, /*NoMerge=*/false);
4029 }
4030
4031 FinishFunction();
4032 // The only reference to this function will be created during LTO link.
4033 // Make sure it survives until then.
4034 CGM.addUsedGlobal(F);
4035 }
4036
EmitUnreachable(SourceLocation Loc)4037 void CodeGenFunction::EmitUnreachable(SourceLocation Loc) {
4038 if (SanOpts.has(SanitizerKind::Unreachable)) {
4039 auto CheckOrdinal = SanitizerKind::SO_Unreachable;
4040 auto CheckHandler = SanitizerHandler::BuiltinUnreachable;
4041 SanitizerDebugLocation SanScope(this, {CheckOrdinal}, CheckHandler);
4042 EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
4043 CheckOrdinal),
4044 CheckHandler, EmitCheckSourceLocation(Loc), {});
4045 }
4046 Builder.CreateUnreachable();
4047 }
4048
EmitTrapCheck(llvm::Value * Checked,SanitizerHandler CheckHandlerID,bool NoMerge)4049 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked,
4050 SanitizerHandler CheckHandlerID,
4051 bool NoMerge) {
4052 llvm::BasicBlock *Cont = createBasicBlock("cont");
4053
4054 // If we're optimizing, collapse all calls to trap down to just one per
4055 // check-type per function to save on code size.
4056 if ((int)TrapBBs.size() <= CheckHandlerID)
4057 TrapBBs.resize(CheckHandlerID + 1);
4058
4059 llvm::BasicBlock *&TrapBB = TrapBBs[CheckHandlerID];
4060
4061 NoMerge = NoMerge || !CGM.getCodeGenOpts().OptimizationLevel ||
4062 (CurCodeDecl && CurCodeDecl->hasAttr<OptimizeNoneAttr>());
4063
4064 llvm::MDBuilder MDHelper(getLLVMContext());
4065 if (TrapBB && !NoMerge) {
4066 auto Call = TrapBB->begin();
4067 assert(isa<llvm::CallInst>(Call) && "Expected call in trap BB");
4068
4069 Call->applyMergedLocation(Call->getDebugLoc(),
4070 Builder.getCurrentDebugLocation());
4071 Builder.CreateCondBr(Checked, Cont, TrapBB,
4072 MDHelper.createLikelyBranchWeights());
4073 } else {
4074 TrapBB = createBasicBlock("trap");
4075 Builder.CreateCondBr(Checked, Cont, TrapBB,
4076 MDHelper.createLikelyBranchWeights());
4077 EmitBlock(TrapBB);
4078
4079 llvm::CallInst *TrapCall =
4080 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::ubsantrap),
4081 llvm::ConstantInt::get(CGM.Int8Ty, CheckHandlerID));
4082
4083 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
4084 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
4085 CGM.getCodeGenOpts().TrapFuncName);
4086 TrapCall->addFnAttr(A);
4087 }
4088 if (NoMerge)
4089 TrapCall->addFnAttr(llvm::Attribute::NoMerge);
4090 TrapCall->setDoesNotReturn();
4091 TrapCall->setDoesNotThrow();
4092 Builder.CreateUnreachable();
4093 }
4094
4095 EmitBlock(Cont);
4096 }
4097
EmitTrapCall(llvm::Intrinsic::ID IntrID)4098 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
4099 llvm::CallInst *TrapCall =
4100 Builder.CreateCall(CGM.getIntrinsic(IntrID));
4101
4102 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
4103 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
4104 CGM.getCodeGenOpts().TrapFuncName);
4105 TrapCall->addFnAttr(A);
4106 }
4107
4108 if (InNoMergeAttributedStmt)
4109 TrapCall->addFnAttr(llvm::Attribute::NoMerge);
4110 return TrapCall;
4111 }
4112
EmitArrayToPointerDecay(const Expr * E,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo)4113 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
4114 LValueBaseInfo *BaseInfo,
4115 TBAAAccessInfo *TBAAInfo) {
4116 assert(E->getType()->isArrayType() &&
4117 "Array to pointer decay must have array source type!");
4118
4119 // Expressions of array type can't be bitfields or vector elements.
4120 LValue LV = EmitLValue(E);
4121 Address Addr = LV.getAddress();
4122
4123 // If the array type was an incomplete type, we need to make sure
4124 // the decay ends up being the right type.
4125 llvm::Type *NewTy = ConvertType(E->getType());
4126 Addr = Addr.withElementType(NewTy);
4127
4128 // Note that VLA pointers are always decayed, so we don't need to do
4129 // anything here.
4130 if (!E->getType()->isVariableArrayType()) {
4131 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
4132 "Expected pointer to array");
4133 Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
4134 }
4135
4136 // The result of this decay conversion points to an array element within the
4137 // base lvalue. However, since TBAA currently does not support representing
4138 // accesses to elements of member arrays, we conservatively represent accesses
4139 // to the pointee object as if it had no any base lvalue specified.
4140 // TODO: Support TBAA for member arrays.
4141 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
4142 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
4143 if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
4144
4145 return Addr.withElementType(ConvertTypeForMem(EltType));
4146 }
4147
4148 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
4149 /// array to pointer, return the array subexpression.
isSimpleArrayDecayOperand(const Expr * E)4150 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
4151 // If this isn't just an array->pointer decay, bail out.
4152 const auto *CE = dyn_cast<CastExpr>(E);
4153 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
4154 return nullptr;
4155
4156 // If this is a decay from variable width array, bail out.
4157 const Expr *SubExpr = CE->getSubExpr();
4158 if (SubExpr->getType()->isVariableArrayType())
4159 return nullptr;
4160
4161 return SubExpr;
4162 }
4163
emitArraySubscriptGEP(CodeGenFunction & CGF,llvm::Type * elemType,llvm::Value * ptr,ArrayRef<llvm::Value * > indices,bool inbounds,bool signedIndices,SourceLocation loc,const llvm::Twine & name="arrayidx")4164 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
4165 llvm::Type *elemType,
4166 llvm::Value *ptr,
4167 ArrayRef<llvm::Value*> indices,
4168 bool inbounds,
4169 bool signedIndices,
4170 SourceLocation loc,
4171 const llvm::Twine &name = "arrayidx") {
4172 if (inbounds) {
4173 return CGF.EmitCheckedInBoundsGEP(elemType, ptr, indices, signedIndices,
4174 CodeGenFunction::NotSubtraction, loc,
4175 name);
4176 } else {
4177 return CGF.Builder.CreateGEP(elemType, ptr, indices, name);
4178 }
4179 }
4180
emitArraySubscriptGEP(CodeGenFunction & CGF,Address addr,ArrayRef<llvm::Value * > indices,llvm::Type * elementType,bool inbounds,bool signedIndices,SourceLocation loc,CharUnits align,const llvm::Twine & name="arrayidx")4181 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
4182 ArrayRef<llvm::Value *> indices,
4183 llvm::Type *elementType, bool inbounds,
4184 bool signedIndices, SourceLocation loc,
4185 CharUnits align,
4186 const llvm::Twine &name = "arrayidx") {
4187 if (inbounds) {
4188 return CGF.EmitCheckedInBoundsGEP(addr, indices, elementType, signedIndices,
4189 CodeGenFunction::NotSubtraction, loc,
4190 align, name);
4191 } else {
4192 return CGF.Builder.CreateGEP(addr, indices, elementType, align, name);
4193 }
4194 }
4195
getArrayElementAlign(CharUnits arrayAlign,llvm::Value * idx,CharUnits eltSize)4196 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
4197 llvm::Value *idx,
4198 CharUnits eltSize) {
4199 // If we have a constant index, we can use the exact offset of the
4200 // element we're accessing.
4201 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
4202 CharUnits offset = constantIdx->getZExtValue() * eltSize;
4203 return arrayAlign.alignmentAtOffset(offset);
4204
4205 // Otherwise, use the worst-case alignment for any element.
4206 } else {
4207 return arrayAlign.alignmentOfArrayElement(eltSize);
4208 }
4209 }
4210
getFixedSizeElementType(const ASTContext & ctx,const VariableArrayType * vla)4211 static QualType getFixedSizeElementType(const ASTContext &ctx,
4212 const VariableArrayType *vla) {
4213 QualType eltType;
4214 do {
4215 eltType = vla->getElementType();
4216 } while ((vla = ctx.getAsVariableArrayType(eltType)));
4217 return eltType;
4218 }
4219
hasBPFPreserveStaticOffset(const RecordDecl * D)4220 static bool hasBPFPreserveStaticOffset(const RecordDecl *D) {
4221 return D && D->hasAttr<BPFPreserveStaticOffsetAttr>();
4222 }
4223
hasBPFPreserveStaticOffset(const Expr * E)4224 static bool hasBPFPreserveStaticOffset(const Expr *E) {
4225 if (!E)
4226 return false;
4227 QualType PointeeType = E->getType()->getPointeeType();
4228 if (PointeeType.isNull())
4229 return false;
4230 if (const auto *BaseDecl = PointeeType->getAsRecordDecl())
4231 return hasBPFPreserveStaticOffset(BaseDecl);
4232 return false;
4233 }
4234
4235 // Wraps Addr with a call to llvm.preserve.static.offset intrinsic.
wrapWithBPFPreserveStaticOffset(CodeGenFunction & CGF,Address & Addr)4236 static Address wrapWithBPFPreserveStaticOffset(CodeGenFunction &CGF,
4237 Address &Addr) {
4238 if (!CGF.getTarget().getTriple().isBPF())
4239 return Addr;
4240
4241 llvm::Function *Fn =
4242 CGF.CGM.getIntrinsic(llvm::Intrinsic::preserve_static_offset);
4243 llvm::CallInst *Call = CGF.Builder.CreateCall(Fn, {Addr.emitRawPointer(CGF)});
4244 return Address(Call, Addr.getElementType(), Addr.getAlignment());
4245 }
4246
4247 /// Given an array base, check whether its member access belongs to a record
4248 /// with preserve_access_index attribute or not.
IsPreserveAIArrayBase(CodeGenFunction & CGF,const Expr * ArrayBase)4249 static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) {
4250 if (!ArrayBase || !CGF.getDebugInfo())
4251 return false;
4252
4253 // Only support base as either a MemberExpr or DeclRefExpr.
4254 // DeclRefExpr to cover cases like:
4255 // struct s { int a; int b[10]; };
4256 // struct s *p;
4257 // p[1].a
4258 // p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr.
4259 // p->b[5] is a MemberExpr example.
4260 const Expr *E = ArrayBase->IgnoreImpCasts();
4261 if (const auto *ME = dyn_cast<MemberExpr>(E))
4262 return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
4263
4264 if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
4265 const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl());
4266 if (!VarDef)
4267 return false;
4268
4269 const auto *PtrT = VarDef->getType()->getAs<PointerType>();
4270 if (!PtrT)
4271 return false;
4272
4273 const auto *PointeeT = PtrT->getPointeeType()
4274 ->getUnqualifiedDesugaredType();
4275 if (const auto *RecT = dyn_cast<RecordType>(PointeeT))
4276 return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
4277 return false;
4278 }
4279
4280 return false;
4281 }
4282
emitArraySubscriptGEP(CodeGenFunction & CGF,Address addr,ArrayRef<llvm::Value * > indices,QualType eltType,bool inbounds,bool signedIndices,SourceLocation loc,QualType * arrayType=nullptr,const Expr * Base=nullptr,const llvm::Twine & name="arrayidx")4283 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
4284 ArrayRef<llvm::Value *> indices,
4285 QualType eltType, bool inbounds,
4286 bool signedIndices, SourceLocation loc,
4287 QualType *arrayType = nullptr,
4288 const Expr *Base = nullptr,
4289 const llvm::Twine &name = "arrayidx") {
4290 // All the indices except that last must be zero.
4291 #ifndef NDEBUG
4292 for (auto *idx : indices.drop_back())
4293 assert(isa<llvm::ConstantInt>(idx) &&
4294 cast<llvm::ConstantInt>(idx)->isZero());
4295 #endif
4296
4297 // Determine the element size of the statically-sized base. This is
4298 // the thing that the indices are expressed in terms of.
4299 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
4300 eltType = getFixedSizeElementType(CGF.getContext(), vla);
4301 }
4302
4303 // We can use that to compute the best alignment of the element.
4304 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
4305 CharUnits eltAlign =
4306 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
4307
4308 if (hasBPFPreserveStaticOffset(Base))
4309 addr = wrapWithBPFPreserveStaticOffset(CGF, addr);
4310
4311 llvm::Value *eltPtr;
4312 auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
4313 if (!LastIndex ||
4314 (!CGF.IsInPreservedAIRegion && !IsPreserveAIArrayBase(CGF, Base))) {
4315 addr = emitArraySubscriptGEP(CGF, addr, indices,
4316 CGF.ConvertTypeForMem(eltType), inbounds,
4317 signedIndices, loc, eltAlign, name);
4318 return addr;
4319 } else {
4320 // Remember the original array subscript for bpf target
4321 unsigned idx = LastIndex->getZExtValue();
4322 llvm::DIType *DbgInfo = nullptr;
4323 if (arrayType)
4324 DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc);
4325 eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(
4326 addr.getElementType(), addr.emitRawPointer(CGF), indices.size() - 1,
4327 idx, DbgInfo);
4328 }
4329
4330 return Address(eltPtr, CGF.ConvertTypeForMem(eltType), eltAlign);
4331 }
4332
4333 namespace {
4334
4335 /// StructFieldAccess is a simple visitor class to grab the first l-value to
4336 /// r-value cast Expr.
4337 struct StructFieldAccess
4338 : public ConstStmtVisitor<StructFieldAccess, const Expr *> {
VisitCastExpr__anonc1809d070511::StructFieldAccess4339 const Expr *VisitCastExpr(const CastExpr *E) {
4340 if (E->getCastKind() == CK_LValueToRValue)
4341 return E;
4342 return Visit(E->getSubExpr());
4343 }
VisitParenExpr__anonc1809d070511::StructFieldAccess4344 const Expr *VisitParenExpr(const ParenExpr *E) {
4345 return Visit(E->getSubExpr());
4346 }
4347 };
4348
4349 } // end anonymous namespace
4350
4351 /// The offset of a field from the beginning of the record.
getFieldOffsetInBits(CodeGenFunction & CGF,const RecordDecl * RD,const FieldDecl * Field,int64_t & Offset)4352 static bool getFieldOffsetInBits(CodeGenFunction &CGF, const RecordDecl *RD,
4353 const FieldDecl *Field, int64_t &Offset) {
4354 ASTContext &Ctx = CGF.getContext();
4355 const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(RD);
4356 unsigned FieldNo = 0;
4357
4358 for (const FieldDecl *FD : RD->fields()) {
4359 if (FD == Field) {
4360 Offset += Layout.getFieldOffset(FieldNo);
4361 return true;
4362 }
4363
4364 QualType Ty = FD->getType();
4365 if (Ty->isRecordType())
4366 if (getFieldOffsetInBits(CGF, Ty->getAsRecordDecl(), Field, Offset)) {
4367 Offset += Layout.getFieldOffset(FieldNo);
4368 return true;
4369 }
4370
4371 if (!RD->isUnion())
4372 ++FieldNo;
4373 }
4374
4375 return false;
4376 }
4377
4378 /// Returns the relative offset difference between \p FD1 and \p FD2.
4379 /// \code
4380 /// offsetof(struct foo, FD1) - offsetof(struct foo, FD2)
4381 /// \endcode
4382 /// Both fields must be within the same struct.
getOffsetDifferenceInBits(CodeGenFunction & CGF,const FieldDecl * FD1,const FieldDecl * FD2)4383 static std::optional<int64_t> getOffsetDifferenceInBits(CodeGenFunction &CGF,
4384 const FieldDecl *FD1,
4385 const FieldDecl *FD2) {
4386 const RecordDecl *FD1OuterRec =
4387 FD1->getParent()->getOuterLexicalRecordContext();
4388 const RecordDecl *FD2OuterRec =
4389 FD2->getParent()->getOuterLexicalRecordContext();
4390
4391 if (FD1OuterRec != FD2OuterRec)
4392 // Fields must be within the same RecordDecl.
4393 return std::optional<int64_t>();
4394
4395 int64_t FD1Offset = 0;
4396 if (!getFieldOffsetInBits(CGF, FD1OuterRec, FD1, FD1Offset))
4397 return std::optional<int64_t>();
4398
4399 int64_t FD2Offset = 0;
4400 if (!getFieldOffsetInBits(CGF, FD2OuterRec, FD2, FD2Offset))
4401 return std::optional<int64_t>();
4402
4403 return std::make_optional<int64_t>(FD1Offset - FD2Offset);
4404 }
4405
4406 /// EmitCountedByBoundsChecking - If the array being accessed has a "counted_by"
4407 /// attribute, generate bounds checking code. The "count" field is at the top
4408 /// level of the struct or in an anonymous struct, that's also at the top level.
4409 /// Future expansions may allow the "count" to reside at any place in the
4410 /// struct, but the value of "counted_by" will be a "simple" path to the count,
4411 /// i.e. "a.b.count", so we shouldn't need the full force of EmitLValue or
4412 /// similar to emit the correct GEP.
EmitCountedByBoundsChecking(const Expr * E,llvm::Value * Idx,Address Addr,QualType IdxTy,QualType ArrayTy,bool Accessed,bool FlexibleArray)4413 void CodeGenFunction::EmitCountedByBoundsChecking(
4414 const Expr *E, llvm::Value *Idx, Address Addr, QualType IdxTy,
4415 QualType ArrayTy, bool Accessed, bool FlexibleArray) {
4416 const auto *ME = dyn_cast<MemberExpr>(E->IgnoreImpCasts());
4417 if (!ME || !ME->getMemberDecl()->getType()->isCountAttributedType())
4418 return;
4419
4420 const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
4421 getLangOpts().getStrictFlexArraysLevel();
4422 if (FlexibleArray &&
4423 !ME->isFlexibleArrayMemberLike(getContext(), StrictFlexArraysLevel))
4424 return;
4425
4426 const FieldDecl *FD = cast<FieldDecl>(ME->getMemberDecl());
4427 const FieldDecl *CountFD = FD->findCountedByField();
4428 if (!CountFD)
4429 return;
4430
4431 if (std::optional<int64_t> Diff =
4432 getOffsetDifferenceInBits(*this, CountFD, FD)) {
4433 if (!Addr.isValid()) {
4434 // An invalid Address indicates we're checking a pointer array access.
4435 // Emit the checked L-Value here.
4436 LValue LV = EmitCheckedLValue(E, TCK_MemberAccess);
4437 Addr = LV.getAddress();
4438 }
4439
4440 // FIXME: The 'static_cast' is necessary, otherwise the result turns into a
4441 // uint64_t, which messes things up if we have a negative offset difference.
4442 Diff = *Diff / static_cast<int64_t>(CGM.getContext().getCharWidth());
4443
4444 // Create a GEP with the byte offset between the counted object and the
4445 // count and use that to load the count value.
4446 Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, Int8PtrTy, Int8Ty);
4447
4448 llvm::Type *CountTy = ConvertType(CountFD->getType());
4449 llvm::Value *Res =
4450 Builder.CreateInBoundsGEP(Int8Ty, Addr.emitRawPointer(*this),
4451 Builder.getInt32(*Diff), ".counted_by.gep");
4452 Res = Builder.CreateAlignedLoad(CountTy, Res, getIntAlign(),
4453 ".counted_by.load");
4454
4455 // Now emit the bounds checking.
4456 EmitBoundsCheckImpl(E, Res, Idx, IdxTy, ArrayTy, Accessed);
4457 }
4458 }
4459
EmitArraySubscriptExpr(const ArraySubscriptExpr * E,bool Accessed)4460 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
4461 bool Accessed) {
4462 // The index must always be an integer, which is not an aggregate. Emit it
4463 // in lexical order (this complexity is, sadly, required by C++17).
4464 llvm::Value *IdxPre =
4465 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
4466 bool SignedIndices = false;
4467 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
4468 auto *Idx = IdxPre;
4469 if (E->getLHS() != E->getIdx()) {
4470 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
4471 Idx = EmitScalarExpr(E->getIdx());
4472 }
4473
4474 QualType IdxTy = E->getIdx()->getType();
4475 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
4476 SignedIndices |= IdxSigned;
4477
4478 if (SanOpts.has(SanitizerKind::ArrayBounds))
4479 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
4480
4481 // Extend or truncate the index type to 32 or 64-bits.
4482 if (Promote && Idx->getType() != IntPtrTy)
4483 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
4484
4485 return Idx;
4486 };
4487 IdxPre = nullptr;
4488
4489 // If the base is a vector type, then we are forming a vector element lvalue
4490 // with this subscript.
4491 if (E->getBase()->getType()->isSubscriptableVectorType() &&
4492 !isa<ExtVectorElementExpr>(E->getBase())) {
4493 // Emit the vector as an lvalue to get its address.
4494 LValue LHS = EmitLValue(E->getBase());
4495 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
4496 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
4497 return LValue::MakeVectorElt(LHS.getAddress(), Idx, E->getBase()->getType(),
4498 LHS.getBaseInfo(), TBAAAccessInfo());
4499 }
4500
4501 // All the other cases basically behave like simple offsetting.
4502
4503 // Handle the extvector case we ignored above.
4504 if (isa<ExtVectorElementExpr>(E->getBase())) {
4505 LValue LV = EmitLValue(E->getBase());
4506 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4507 Address Addr = EmitExtVectorElementLValue(LV);
4508
4509 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
4510 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
4511 SignedIndices, E->getExprLoc());
4512 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
4513 CGM.getTBAAInfoForSubobject(LV, EltType));
4514 }
4515
4516 LValueBaseInfo EltBaseInfo;
4517 TBAAAccessInfo EltTBAAInfo;
4518 Address Addr = Address::invalid();
4519 if (const VariableArrayType *vla =
4520 getContext().getAsVariableArrayType(E->getType())) {
4521 // The base must be a pointer, which is not an aggregate. Emit
4522 // it. It needs to be emitted first in case it's what captures
4523 // the VLA bounds.
4524 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4525 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4526
4527 // The element count here is the total number of non-VLA elements.
4528 llvm::Value *numElements = getVLASize(vla).NumElts;
4529
4530 // Effectively, the multiply by the VLA size is part of the GEP.
4531 // GEP indexes are signed, and scaling an index isn't permitted to
4532 // signed-overflow, so we use the same semantics for our explicit
4533 // multiply. We suppress this if overflow is not undefined behavior.
4534 if (getLangOpts().PointerOverflowDefined) {
4535 Idx = Builder.CreateMul(Idx, numElements);
4536 } else {
4537 Idx = Builder.CreateNSWMul(Idx, numElements);
4538 }
4539
4540 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
4541 !getLangOpts().PointerOverflowDefined,
4542 SignedIndices, E->getExprLoc());
4543
4544 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
4545 // Indexing over an interface, as in "NSString *P; P[4];"
4546
4547 // Emit the base pointer.
4548 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4549 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4550
4551 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
4552 llvm::Value *InterfaceSizeVal =
4553 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
4554
4555 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
4556
4557 // We don't necessarily build correct LLVM struct types for ObjC
4558 // interfaces, so we can't rely on GEP to do this scaling
4559 // correctly, so we need to cast to i8*. FIXME: is this actually
4560 // true? A lot of other things in the fragile ABI would break...
4561 llvm::Type *OrigBaseElemTy = Addr.getElementType();
4562
4563 // Do the GEP.
4564 CharUnits EltAlign =
4565 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
4566 llvm::Value *EltPtr =
4567 emitArraySubscriptGEP(*this, Int8Ty, Addr.emitRawPointer(*this),
4568 ScaledIdx, false, SignedIndices, E->getExprLoc());
4569 Addr = Address(EltPtr, OrigBaseElemTy, EltAlign);
4570 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
4571 // If this is A[i] where A is an array, the frontend will have decayed the
4572 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
4573 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
4574 // "gep x, i" here. Emit one "gep A, 0, i".
4575 assert(Array->getType()->isArrayType() &&
4576 "Array to pointer decay must have array source type!");
4577 LValue ArrayLV;
4578 // For simple multidimensional array indexing, set the 'accessed' flag for
4579 // better bounds-checking of the base expression.
4580 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
4581 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
4582 else
4583 ArrayLV = EmitLValue(Array);
4584 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4585
4586 if (SanOpts.has(SanitizerKind::ArrayBounds))
4587 EmitCountedByBoundsChecking(Array, Idx, ArrayLV.getAddress(),
4588 E->getIdx()->getType(), Array->getType(),
4589 Accessed, /*FlexibleArray=*/true);
4590
4591 // Propagate the alignment from the array itself to the result.
4592 QualType arrayType = Array->getType();
4593 Addr = emitArraySubscriptGEP(
4594 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
4595 E->getType(), !getLangOpts().PointerOverflowDefined, SignedIndices,
4596 E->getExprLoc(), &arrayType, E->getBase());
4597 EltBaseInfo = ArrayLV.getBaseInfo();
4598 if (!CGM.getCodeGenOpts().NewStructPathTBAA) {
4599 // Since CodeGenTBAA::getTypeInfoHelper only handles array types for
4600 // new struct path TBAA, we must a use a plain access.
4601 EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
4602 } else if (ArrayLV.getTBAAInfo().isMayAlias()) {
4603 EltTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4604 } else if (ArrayLV.getTBAAInfo().isIncomplete()) {
4605 // The array element is complete, even if the array is not.
4606 EltTBAAInfo = CGM.getTBAAAccessInfo(E->getType());
4607 } else {
4608 // The TBAA access info from the array (base) lvalue is ordinary. We will
4609 // adapt it to create access info for the element.
4610 EltTBAAInfo = ArrayLV.getTBAAInfo();
4611
4612 // We retain the TBAA struct path (BaseType and Offset members) from the
4613 // array. In the TBAA representation, we map any array access to the
4614 // element at index 0, as the index is generally a runtime value. This
4615 // element has the same offset in the base type as the array itself.
4616 // If the array lvalue had no base type, there is no point trying to
4617 // generate one, since an array itself is not a valid base type.
4618
4619 // We also retain the access type from the base lvalue, but the access
4620 // size must be updated to the size of an individual element.
4621 EltTBAAInfo.Size =
4622 getContext().getTypeSizeInChars(E->getType()).getQuantity();
4623 }
4624 } else {
4625 // The base must be a pointer; emit it with an estimate of its alignment.
4626 Address BaseAddr =
4627 EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4628 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4629 QualType ptrType = E->getBase()->getType();
4630 Addr = emitArraySubscriptGEP(*this, BaseAddr, Idx, E->getType(),
4631 !getLangOpts().PointerOverflowDefined,
4632 SignedIndices, E->getExprLoc(), &ptrType,
4633 E->getBase());
4634
4635 if (SanOpts.has(SanitizerKind::ArrayBounds)) {
4636 StructFieldAccess Visitor;
4637 const Expr *Base = Visitor.Visit(E->getBase());
4638
4639 if (const auto *CE = dyn_cast_if_present<CastExpr>(Base);
4640 CE && CE->getCastKind() == CK_LValueToRValue)
4641 EmitCountedByBoundsChecking(CE, Idx, Address::invalid(),
4642 E->getIdx()->getType(), ptrType, Accessed,
4643 /*FlexibleArray=*/false);
4644 }
4645 }
4646
4647 LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
4648
4649 if (getLangOpts().ObjC &&
4650 getLangOpts().getGC() != LangOptions::NonGC) {
4651 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
4652 setObjCGCLValueClass(getContext(), E, LV);
4653 }
4654 return LV;
4655 }
4656
EmitMatrixIndexExpr(const Expr * E)4657 llvm::Value *CodeGenFunction::EmitMatrixIndexExpr(const Expr *E) {
4658 llvm::Value *Idx = EmitScalarExpr(E);
4659 if (Idx->getType() == IntPtrTy)
4660 return Idx;
4661 bool IsSigned = E->getType()->isSignedIntegerOrEnumerationType();
4662 return Builder.CreateIntCast(Idx, IntPtrTy, IsSigned);
4663 }
4664
EmitMatrixSubscriptExpr(const MatrixSubscriptExpr * E)4665 LValue CodeGenFunction::EmitMatrixSubscriptExpr(const MatrixSubscriptExpr *E) {
4666 assert(
4667 !E->isIncomplete() &&
4668 "incomplete matrix subscript expressions should be rejected during Sema");
4669 LValue Base = EmitLValue(E->getBase());
4670
4671 // Extend or truncate the index type to 32 or 64-bits if needed.
4672 llvm::Value *RowIdx = EmitMatrixIndexExpr(E->getRowIdx());
4673 llvm::Value *ColIdx = EmitMatrixIndexExpr(E->getColumnIdx());
4674
4675 llvm::Value *NumRows = Builder.getIntN(
4676 RowIdx->getType()->getScalarSizeInBits(),
4677 E->getBase()->getType()->castAs<ConstantMatrixType>()->getNumRows());
4678 llvm::Value *FinalIdx =
4679 Builder.CreateAdd(Builder.CreateMul(ColIdx, NumRows), RowIdx);
4680 return LValue::MakeMatrixElt(
4681 MaybeConvertMatrixAddress(Base.getAddress(), *this), FinalIdx,
4682 E->getBase()->getType(), Base.getBaseInfo(), TBAAAccessInfo());
4683 }
4684
emitOMPArraySectionBase(CodeGenFunction & CGF,const Expr * Base,LValueBaseInfo & BaseInfo,TBAAAccessInfo & TBAAInfo,QualType BaseTy,QualType ElTy,bool IsLowerBound)4685 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
4686 LValueBaseInfo &BaseInfo,
4687 TBAAAccessInfo &TBAAInfo,
4688 QualType BaseTy, QualType ElTy,
4689 bool IsLowerBound) {
4690 LValue BaseLVal;
4691 if (auto *ASE = dyn_cast<ArraySectionExpr>(Base->IgnoreParenImpCasts())) {
4692 BaseLVal = CGF.EmitArraySectionExpr(ASE, IsLowerBound);
4693 if (BaseTy->isArrayType()) {
4694 Address Addr = BaseLVal.getAddress();
4695 BaseInfo = BaseLVal.getBaseInfo();
4696
4697 // If the array type was an incomplete type, we need to make sure
4698 // the decay ends up being the right type.
4699 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
4700 Addr = Addr.withElementType(NewTy);
4701
4702 // Note that VLA pointers are always decayed, so we don't need to do
4703 // anything here.
4704 if (!BaseTy->isVariableArrayType()) {
4705 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
4706 "Expected pointer to array");
4707 Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
4708 }
4709
4710 return Addr.withElementType(CGF.ConvertTypeForMem(ElTy));
4711 }
4712 LValueBaseInfo TypeBaseInfo;
4713 TBAAAccessInfo TypeTBAAInfo;
4714 CharUnits Align =
4715 CGF.CGM.getNaturalTypeAlignment(ElTy, &TypeBaseInfo, &TypeTBAAInfo);
4716 BaseInfo.mergeForCast(TypeBaseInfo);
4717 TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
4718 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()),
4719 CGF.ConvertTypeForMem(ElTy), Align);
4720 }
4721 return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
4722 }
4723
EmitArraySectionExpr(const ArraySectionExpr * E,bool IsLowerBound)4724 LValue CodeGenFunction::EmitArraySectionExpr(const ArraySectionExpr *E,
4725 bool IsLowerBound) {
4726
4727 assert(!E->isOpenACCArraySection() &&
4728 "OpenACC Array section codegen not implemented");
4729
4730 QualType BaseTy = ArraySectionExpr::getBaseOriginalType(E->getBase());
4731 QualType ResultExprTy;
4732 if (auto *AT = getContext().getAsArrayType(BaseTy))
4733 ResultExprTy = AT->getElementType();
4734 else
4735 ResultExprTy = BaseTy->getPointeeType();
4736 llvm::Value *Idx = nullptr;
4737 if (IsLowerBound || E->getColonLocFirst().isInvalid()) {
4738 // Requesting lower bound or upper bound, but without provided length and
4739 // without ':' symbol for the default length -> length = 1.
4740 // Idx = LowerBound ?: 0;
4741 if (auto *LowerBound = E->getLowerBound()) {
4742 Idx = Builder.CreateIntCast(
4743 EmitScalarExpr(LowerBound), IntPtrTy,
4744 LowerBound->getType()->hasSignedIntegerRepresentation());
4745 } else
4746 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
4747 } else {
4748 // Try to emit length or lower bound as constant. If this is possible, 1
4749 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
4750 // IR (LB + Len) - 1.
4751 auto &C = CGM.getContext();
4752 auto *Length = E->getLength();
4753 llvm::APSInt ConstLength;
4754 if (Length) {
4755 // Idx = LowerBound + Length - 1;
4756 if (std::optional<llvm::APSInt> CL = Length->getIntegerConstantExpr(C)) {
4757 ConstLength = CL->zextOrTrunc(PointerWidthInBits);
4758 Length = nullptr;
4759 }
4760 auto *LowerBound = E->getLowerBound();
4761 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
4762 if (LowerBound) {
4763 if (std::optional<llvm::APSInt> LB =
4764 LowerBound->getIntegerConstantExpr(C)) {
4765 ConstLowerBound = LB->zextOrTrunc(PointerWidthInBits);
4766 LowerBound = nullptr;
4767 }
4768 }
4769 if (!Length)
4770 --ConstLength;
4771 else if (!LowerBound)
4772 --ConstLowerBound;
4773
4774 if (Length || LowerBound) {
4775 auto *LowerBoundVal =
4776 LowerBound
4777 ? Builder.CreateIntCast(
4778 EmitScalarExpr(LowerBound), IntPtrTy,
4779 LowerBound->getType()->hasSignedIntegerRepresentation())
4780 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
4781 auto *LengthVal =
4782 Length
4783 ? Builder.CreateIntCast(
4784 EmitScalarExpr(Length), IntPtrTy,
4785 Length->getType()->hasSignedIntegerRepresentation())
4786 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
4787 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
4788 /*HasNUW=*/false,
4789 !getLangOpts().PointerOverflowDefined);
4790 if (Length && LowerBound) {
4791 Idx = Builder.CreateSub(
4792 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
4793 /*HasNUW=*/false, !getLangOpts().PointerOverflowDefined);
4794 }
4795 } else
4796 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
4797 } else {
4798 // Idx = ArraySize - 1;
4799 QualType ArrayTy = BaseTy->isPointerType()
4800 ? E->getBase()->IgnoreParenImpCasts()->getType()
4801 : BaseTy;
4802 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
4803 Length = VAT->getSizeExpr();
4804 if (std::optional<llvm::APSInt> L = Length->getIntegerConstantExpr(C)) {
4805 ConstLength = *L;
4806 Length = nullptr;
4807 }
4808 } else {
4809 auto *CAT = C.getAsConstantArrayType(ArrayTy);
4810 assert(CAT && "unexpected type for array initializer");
4811 ConstLength = CAT->getSize();
4812 }
4813 if (Length) {
4814 auto *LengthVal = Builder.CreateIntCast(
4815 EmitScalarExpr(Length), IntPtrTy,
4816 Length->getType()->hasSignedIntegerRepresentation());
4817 Idx = Builder.CreateSub(
4818 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
4819 /*HasNUW=*/false, !getLangOpts().PointerOverflowDefined);
4820 } else {
4821 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
4822 --ConstLength;
4823 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
4824 }
4825 }
4826 }
4827 assert(Idx);
4828
4829 Address EltPtr = Address::invalid();
4830 LValueBaseInfo BaseInfo;
4831 TBAAAccessInfo TBAAInfo;
4832 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
4833 // The base must be a pointer, which is not an aggregate. Emit
4834 // it. It needs to be emitted first in case it's what captures
4835 // the VLA bounds.
4836 Address Base =
4837 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
4838 BaseTy, VLA->getElementType(), IsLowerBound);
4839 // The element count here is the total number of non-VLA elements.
4840 llvm::Value *NumElements = getVLASize(VLA).NumElts;
4841
4842 // Effectively, the multiply by the VLA size is part of the GEP.
4843 // GEP indexes are signed, and scaling an index isn't permitted to
4844 // signed-overflow, so we use the same semantics for our explicit
4845 // multiply. We suppress this if overflow is not undefined behavior.
4846 if (getLangOpts().PointerOverflowDefined)
4847 Idx = Builder.CreateMul(Idx, NumElements);
4848 else
4849 Idx = Builder.CreateNSWMul(Idx, NumElements);
4850 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
4851 !getLangOpts().PointerOverflowDefined,
4852 /*signedIndices=*/false, E->getExprLoc());
4853 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
4854 // If this is A[i] where A is an array, the frontend will have decayed the
4855 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
4856 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
4857 // "gep x, i" here. Emit one "gep A, 0, i".
4858 assert(Array->getType()->isArrayType() &&
4859 "Array to pointer decay must have array source type!");
4860 LValue ArrayLV;
4861 // For simple multidimensional array indexing, set the 'accessed' flag for
4862 // better bounds-checking of the base expression.
4863 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
4864 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
4865 else
4866 ArrayLV = EmitLValue(Array);
4867
4868 // Propagate the alignment from the array itself to the result.
4869 EltPtr = emitArraySubscriptGEP(
4870 *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
4871 ResultExprTy, !getLangOpts().PointerOverflowDefined,
4872 /*signedIndices=*/false, E->getExprLoc());
4873 BaseInfo = ArrayLV.getBaseInfo();
4874 TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
4875 } else {
4876 Address Base =
4877 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo, BaseTy,
4878 ResultExprTy, IsLowerBound);
4879 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
4880 !getLangOpts().PointerOverflowDefined,
4881 /*signedIndices=*/false, E->getExprLoc());
4882 }
4883
4884 return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
4885 }
4886
4887 LValue CodeGenFunction::
EmitExtVectorElementExpr(const ExtVectorElementExpr * E)4888 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
4889 // Emit the base vector as an l-value.
4890 LValue Base;
4891
4892 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
4893 if (E->isArrow()) {
4894 // If it is a pointer to a vector, emit the address and form an lvalue with
4895 // it.
4896 LValueBaseInfo BaseInfo;
4897 TBAAAccessInfo TBAAInfo;
4898 Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
4899 const auto *PT = E->getBase()->getType()->castAs<PointerType>();
4900 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
4901 Base.getQuals().removeObjCGCAttr();
4902 } else if (E->getBase()->isGLValue()) {
4903 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
4904 // emit the base as an lvalue.
4905 assert(E->getBase()->getType()->isVectorType());
4906 Base = EmitLValue(E->getBase());
4907 } else {
4908 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
4909 assert(E->getBase()->getType()->isVectorType() &&
4910 "Result must be a vector");
4911 llvm::Value *Vec = EmitScalarExpr(E->getBase());
4912
4913 // Store the vector to memory (because LValue wants an address).
4914 Address VecMem = CreateMemTemp(E->getBase()->getType());
4915 // need to zero extend an hlsl boolean vector to store it back to memory
4916 QualType Ty = E->getBase()->getType();
4917 llvm::Type *LTy = convertTypeForLoadStore(Ty, Vec->getType());
4918 if (LTy->getScalarSizeInBits() > Vec->getType()->getScalarSizeInBits())
4919 Vec = Builder.CreateZExt(Vec, LTy);
4920 Builder.CreateStore(Vec, VecMem);
4921 Base = MakeAddrLValue(VecMem, Ty, AlignmentSource::Decl);
4922 }
4923
4924 QualType type =
4925 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
4926
4927 // Encode the element access list into a vector of unsigned indices.
4928 SmallVector<uint32_t, 4> Indices;
4929 E->getEncodedElementAccess(Indices);
4930
4931 if (Base.isSimple()) {
4932 llvm::Constant *CV =
4933 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
4934 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type,
4935 Base.getBaseInfo(), TBAAAccessInfo());
4936 }
4937 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
4938
4939 llvm::Constant *BaseElts = Base.getExtVectorElts();
4940 SmallVector<llvm::Constant *, 4> CElts;
4941
4942 for (unsigned Index : Indices)
4943 CElts.push_back(BaseElts->getAggregateElement(Index));
4944 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
4945 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
4946 Base.getBaseInfo(), TBAAAccessInfo());
4947 }
4948
isUnderlyingBasePointerConstantNull(const Expr * E)4949 bool CodeGenFunction::isUnderlyingBasePointerConstantNull(const Expr *E) {
4950 const Expr *UnderlyingBaseExpr = E->IgnoreParens();
4951 while (auto *BaseMemberExpr = dyn_cast<MemberExpr>(UnderlyingBaseExpr))
4952 UnderlyingBaseExpr = BaseMemberExpr->getBase()->IgnoreParens();
4953 return getContext().isSentinelNullExpr(UnderlyingBaseExpr);
4954 }
4955
EmitMemberExpr(const MemberExpr * E)4956 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
4957 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
4958 EmitIgnoredExpr(E->getBase());
4959 return EmitDeclRefLValue(DRE);
4960 }
4961
4962 Expr *BaseExpr = E->getBase();
4963 // Check whether the underlying base pointer is a constant null.
4964 // If so, we do not set inbounds flag for GEP to avoid breaking some
4965 // old-style offsetof idioms.
4966 bool IsInBounds = !getLangOpts().PointerOverflowDefined &&
4967 !isUnderlyingBasePointerConstantNull(BaseExpr);
4968 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
4969 LValue BaseLV;
4970 if (E->isArrow()) {
4971 LValueBaseInfo BaseInfo;
4972 TBAAAccessInfo TBAAInfo;
4973 Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
4974 QualType PtrTy = BaseExpr->getType()->getPointeeType();
4975 SanitizerSet SkippedChecks;
4976 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
4977 if (IsBaseCXXThis)
4978 SkippedChecks.set(SanitizerKind::Alignment, true);
4979 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
4980 SkippedChecks.set(SanitizerKind::Null, true);
4981 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr, PtrTy,
4982 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
4983 BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
4984 } else
4985 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
4986
4987 NamedDecl *ND = E->getMemberDecl();
4988 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
4989 LValue LV = EmitLValueForField(BaseLV, Field, IsInBounds);
4990 setObjCGCLValueClass(getContext(), E, LV);
4991 if (getLangOpts().OpenMP) {
4992 // If the member was explicitly marked as nontemporal, mark it as
4993 // nontemporal. If the base lvalue is marked as nontemporal, mark access
4994 // to children as nontemporal too.
4995 if ((IsWrappedCXXThis(BaseExpr) &&
4996 CGM.getOpenMPRuntime().isNontemporalDecl(Field)) ||
4997 BaseLV.isNontemporal())
4998 LV.setNontemporal(/*Value=*/true);
4999 }
5000 return LV;
5001 }
5002
5003 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
5004 return EmitFunctionDeclLValue(*this, E, FD);
5005
5006 llvm_unreachable("Unhandled member declaration!");
5007 }
5008
5009 /// Given that we are currently emitting a lambda, emit an l-value for
5010 /// one of its members.
5011 ///
EmitLValueForLambdaField(const FieldDecl * Field,llvm::Value * ThisValue)5012 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field,
5013 llvm::Value *ThisValue) {
5014 bool HasExplicitObjectParameter = false;
5015 const auto *MD = dyn_cast_if_present<CXXMethodDecl>(CurCodeDecl);
5016 if (MD) {
5017 HasExplicitObjectParameter = MD->isExplicitObjectMemberFunction();
5018 assert(MD->getParent()->isLambda());
5019 assert(MD->getParent() == Field->getParent());
5020 }
5021 LValue LambdaLV;
5022 if (HasExplicitObjectParameter) {
5023 const VarDecl *D = cast<CXXMethodDecl>(CurCodeDecl)->getParamDecl(0);
5024 auto It = LocalDeclMap.find(D);
5025 assert(It != LocalDeclMap.end() && "explicit parameter not loaded?");
5026 Address AddrOfExplicitObject = It->getSecond();
5027 if (D->getType()->isReferenceType())
5028 LambdaLV = EmitLoadOfReferenceLValue(AddrOfExplicitObject, D->getType(),
5029 AlignmentSource::Decl);
5030 else
5031 LambdaLV = MakeAddrLValue(AddrOfExplicitObject,
5032 D->getType().getNonReferenceType());
5033
5034 // Make sure we have an lvalue to the lambda itself and not a derived class.
5035 auto *ThisTy = D->getType().getNonReferenceType()->getAsCXXRecordDecl();
5036 auto *LambdaTy = cast<CXXRecordDecl>(Field->getParent());
5037 if (ThisTy != LambdaTy) {
5038 const CXXCastPath &BasePathArray = getContext().LambdaCastPaths.at(MD);
5039 Address Base = GetAddressOfBaseClass(
5040 LambdaLV.getAddress(), ThisTy, BasePathArray.begin(),
5041 BasePathArray.end(), /*NullCheckValue=*/false, SourceLocation());
5042 LambdaLV = MakeAddrLValue(Base, QualType{LambdaTy->getTypeForDecl(), 0});
5043 }
5044 } else {
5045 QualType LambdaTagType = getContext().getTagDeclType(Field->getParent());
5046 LambdaLV = MakeNaturalAlignAddrLValue(ThisValue, LambdaTagType);
5047 }
5048 return EmitLValueForField(LambdaLV, Field);
5049 }
5050
EmitLValueForLambdaField(const FieldDecl * Field)5051 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
5052 return EmitLValueForLambdaField(Field, CXXABIThisValue);
5053 }
5054
5055 /// Get the field index in the debug info. The debug info structure/union
5056 /// will ignore the unnamed bitfields.
getDebugInfoFIndex(const RecordDecl * Rec,unsigned FieldIndex)5057 unsigned CodeGenFunction::getDebugInfoFIndex(const RecordDecl *Rec,
5058 unsigned FieldIndex) {
5059 unsigned I = 0, Skipped = 0;
5060
5061 for (auto *F : Rec->getDefinition()->fields()) {
5062 if (I == FieldIndex)
5063 break;
5064 if (F->isUnnamedBitField())
5065 Skipped++;
5066 I++;
5067 }
5068
5069 return FieldIndex - Skipped;
5070 }
5071
5072 /// Get the address of a zero-sized field within a record. The resulting
5073 /// address doesn't necessarily have the right type.
emitAddrOfZeroSizeField(CodeGenFunction & CGF,Address Base,const FieldDecl * Field,bool IsInBounds)5074 static Address emitAddrOfZeroSizeField(CodeGenFunction &CGF, Address Base,
5075 const FieldDecl *Field,
5076 bool IsInBounds) {
5077 CharUnits Offset = CGF.getContext().toCharUnitsFromBits(
5078 CGF.getContext().getFieldOffset(Field));
5079 if (Offset.isZero())
5080 return Base;
5081 Base = Base.withElementType(CGF.Int8Ty);
5082 if (!IsInBounds)
5083 return CGF.Builder.CreateConstByteGEP(Base, Offset);
5084 return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset);
5085 }
5086
5087 /// Drill down to the storage of a field without walking into
5088 /// reference types.
5089 ///
5090 /// The resulting address doesn't necessarily have the right type.
emitAddrOfFieldStorage(CodeGenFunction & CGF,Address base,const FieldDecl * field,bool IsInBounds)5091 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
5092 const FieldDecl *field, bool IsInBounds) {
5093 if (isEmptyFieldForLayout(CGF.getContext(), field))
5094 return emitAddrOfZeroSizeField(CGF, base, field, IsInBounds);
5095
5096 const RecordDecl *rec = field->getParent();
5097
5098 unsigned idx =
5099 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
5100
5101 if (!IsInBounds)
5102 return CGF.Builder.CreateConstGEP2_32(base, 0, idx, field->getName());
5103
5104 return CGF.Builder.CreateStructGEP(base, idx, field->getName());
5105 }
5106
emitPreserveStructAccess(CodeGenFunction & CGF,LValue base,Address addr,const FieldDecl * field)5107 static Address emitPreserveStructAccess(CodeGenFunction &CGF, LValue base,
5108 Address addr, const FieldDecl *field) {
5109 const RecordDecl *rec = field->getParent();
5110 llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(
5111 base.getType(), rec->getLocation());
5112
5113 unsigned idx =
5114 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
5115
5116 return CGF.Builder.CreatePreserveStructAccessIndex(
5117 addr, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
5118 }
5119
hasAnyVptr(const QualType Type,const ASTContext & Context)5120 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
5121 const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
5122 if (!RD)
5123 return false;
5124
5125 if (RD->isDynamicClass())
5126 return true;
5127
5128 for (const auto &Base : RD->bases())
5129 if (hasAnyVptr(Base.getType(), Context))
5130 return true;
5131
5132 for (const FieldDecl *Field : RD->fields())
5133 if (hasAnyVptr(Field->getType(), Context))
5134 return true;
5135
5136 return false;
5137 }
5138
EmitLValueForField(LValue base,const FieldDecl * field,bool IsInBounds)5139 LValue CodeGenFunction::EmitLValueForField(LValue base, const FieldDecl *field,
5140 bool IsInBounds) {
5141 LValueBaseInfo BaseInfo = base.getBaseInfo();
5142
5143 if (field->isBitField()) {
5144 const CGRecordLayout &RL =
5145 CGM.getTypes().getCGRecordLayout(field->getParent());
5146 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
5147 const bool UseVolatile = isAAPCS(CGM.getTarget()) &&
5148 CGM.getCodeGenOpts().AAPCSBitfieldWidth &&
5149 Info.VolatileStorageSize != 0 &&
5150 field->getType()
5151 .withCVRQualifiers(base.getVRQualifiers())
5152 .isVolatileQualified();
5153 Address Addr = base.getAddress();
5154 unsigned Idx = RL.getLLVMFieldNo(field);
5155 const RecordDecl *rec = field->getParent();
5156 if (hasBPFPreserveStaticOffset(rec))
5157 Addr = wrapWithBPFPreserveStaticOffset(*this, Addr);
5158 if (!UseVolatile) {
5159 if (!IsInPreservedAIRegion &&
5160 (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
5161 if (Idx != 0) {
5162 // For structs, we GEP to the field that the record layout suggests.
5163 if (!IsInBounds)
5164 Addr = Builder.CreateConstGEP2_32(Addr, 0, Idx, field->getName());
5165 else
5166 Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
5167 }
5168 } else {
5169 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
5170 getContext().getRecordType(rec), rec->getLocation());
5171 Addr = Builder.CreatePreserveStructAccessIndex(
5172 Addr, Idx, getDebugInfoFIndex(rec, field->getFieldIndex()),
5173 DbgInfo);
5174 }
5175 }
5176 const unsigned SS =
5177 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
5178 // Get the access type.
5179 llvm::Type *FieldIntTy = llvm::Type::getIntNTy(getLLVMContext(), SS);
5180 Addr = Addr.withElementType(FieldIntTy);
5181 if (UseVolatile) {
5182 const unsigned VolatileOffset = Info.VolatileStorageOffset.getQuantity();
5183 if (VolatileOffset)
5184 Addr = Builder.CreateConstInBoundsGEP(Addr, VolatileOffset);
5185 }
5186
5187 QualType fieldType =
5188 field->getType().withCVRQualifiers(base.getVRQualifiers());
5189 // TODO: Support TBAA for bit fields.
5190 LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
5191 return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
5192 TBAAAccessInfo());
5193 }
5194
5195 // Fields of may-alias structures are may-alias themselves.
5196 // FIXME: this should get propagated down through anonymous structs
5197 // and unions.
5198 QualType FieldType = field->getType();
5199 const RecordDecl *rec = field->getParent();
5200 AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
5201 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
5202 TBAAAccessInfo FieldTBAAInfo;
5203 if (base.getTBAAInfo().isMayAlias() ||
5204 rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
5205 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
5206 } else if (rec->isUnion()) {
5207 // TODO: Support TBAA for unions.
5208 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
5209 } else {
5210 // If no base type been assigned for the base access, then try to generate
5211 // one for this base lvalue.
5212 FieldTBAAInfo = base.getTBAAInfo();
5213 if (!FieldTBAAInfo.BaseType) {
5214 FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
5215 assert(!FieldTBAAInfo.Offset &&
5216 "Nonzero offset for an access with no base type!");
5217 }
5218
5219 // Adjust offset to be relative to the base type.
5220 const ASTRecordLayout &Layout =
5221 getContext().getASTRecordLayout(field->getParent());
5222 unsigned CharWidth = getContext().getCharWidth();
5223 if (FieldTBAAInfo.BaseType)
5224 FieldTBAAInfo.Offset +=
5225 Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
5226
5227 // Update the final access type and size.
5228 FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
5229 FieldTBAAInfo.Size =
5230 getContext().getTypeSizeInChars(FieldType).getQuantity();
5231 }
5232
5233 Address addr = base.getAddress();
5234 if (hasBPFPreserveStaticOffset(rec))
5235 addr = wrapWithBPFPreserveStaticOffset(*this, addr);
5236 if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
5237 if (CGM.getCodeGenOpts().StrictVTablePointers &&
5238 ClassDef->isDynamicClass()) {
5239 // Getting to any field of dynamic object requires stripping dynamic
5240 // information provided by invariant.group. This is because accessing
5241 // fields may leak the real address of dynamic object, which could result
5242 // in miscompilation when leaked pointer would be compared.
5243 auto *stripped =
5244 Builder.CreateStripInvariantGroup(addr.emitRawPointer(*this));
5245 addr = Address(stripped, addr.getElementType(), addr.getAlignment());
5246 }
5247 }
5248
5249 unsigned RecordCVR = base.getVRQualifiers();
5250 if (rec->isUnion()) {
5251 // For unions, there is no pointer adjustment.
5252 if (CGM.getCodeGenOpts().StrictVTablePointers &&
5253 hasAnyVptr(FieldType, getContext()))
5254 // Because unions can easily skip invariant.barriers, we need to add
5255 // a barrier every time CXXRecord field with vptr is referenced.
5256 addr = Builder.CreateLaunderInvariantGroup(addr);
5257
5258 if (IsInPreservedAIRegion ||
5259 (getDebugInfo() && rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
5260 // Remember the original union field index
5261 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateStandaloneType(base.getType(),
5262 rec->getLocation());
5263 addr =
5264 Address(Builder.CreatePreserveUnionAccessIndex(
5265 addr.emitRawPointer(*this),
5266 getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
5267 addr.getElementType(), addr.getAlignment());
5268 }
5269
5270 if (FieldType->isReferenceType())
5271 addr = addr.withElementType(CGM.getTypes().ConvertTypeForMem(FieldType));
5272 } else {
5273 if (!IsInPreservedAIRegion &&
5274 (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>()))
5275 // For structs, we GEP to the field that the record layout suggests.
5276 addr = emitAddrOfFieldStorage(*this, addr, field, IsInBounds);
5277 else
5278 // Remember the original struct field index
5279 addr = emitPreserveStructAccess(*this, base, addr, field);
5280 }
5281
5282 // If this is a reference field, load the reference right now.
5283 if (FieldType->isReferenceType()) {
5284 LValue RefLVal =
5285 MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
5286 if (RecordCVR & Qualifiers::Volatile)
5287 RefLVal.getQuals().addVolatile();
5288 addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
5289
5290 // Qualifiers on the struct don't apply to the referencee.
5291 RecordCVR = 0;
5292 FieldType = FieldType->getPointeeType();
5293 }
5294
5295 // Make sure that the address is pointing to the right type. This is critical
5296 // for both unions and structs.
5297 addr = addr.withElementType(CGM.getTypes().ConvertTypeForMem(FieldType));
5298
5299 if (field->hasAttr<AnnotateAttr>())
5300 addr = EmitFieldAnnotations(field, addr);
5301
5302 LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
5303 LV.getQuals().addCVRQualifiers(RecordCVR);
5304
5305 // __weak attribute on a field is ignored.
5306 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
5307 LV.getQuals().removeObjCGCAttr();
5308
5309 return LV;
5310 }
5311
5312 LValue
EmitLValueForFieldInitialization(LValue Base,const FieldDecl * Field)5313 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
5314 const FieldDecl *Field) {
5315 QualType FieldType = Field->getType();
5316
5317 if (!FieldType->isReferenceType())
5318 return EmitLValueForField(Base, Field);
5319
5320 Address V = emitAddrOfFieldStorage(
5321 *this, Base.getAddress(), Field,
5322 /*IsInBounds=*/!getLangOpts().PointerOverflowDefined);
5323
5324 // Make sure that the address is pointing to the right type.
5325 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
5326 V = V.withElementType(llvmType);
5327
5328 // TODO: Generate TBAA information that describes this access as a structure
5329 // member access and not just an access to an object of the field's type. This
5330 // should be similar to what we do in EmitLValueForField().
5331 LValueBaseInfo BaseInfo = Base.getBaseInfo();
5332 AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
5333 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
5334 return MakeAddrLValue(V, FieldType, FieldBaseInfo,
5335 CGM.getTBAAInfoForSubobject(Base, FieldType));
5336 }
5337
EmitCompoundLiteralLValue(const CompoundLiteralExpr * E)5338 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
5339 if (E->isFileScope()) {
5340 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
5341 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
5342 }
5343 if (E->getType()->isVariablyModifiedType())
5344 // make sure to emit the VLA size.
5345 EmitVariablyModifiedType(E->getType());
5346
5347 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
5348 const Expr *InitExpr = E->getInitializer();
5349 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
5350
5351 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
5352 /*Init*/ true);
5353
5354 // Block-scope compound literals are destroyed at the end of the enclosing
5355 // scope in C.
5356 if (!getLangOpts().CPlusPlus)
5357 if (QualType::DestructionKind DtorKind = E->getType().isDestructedType())
5358 pushLifetimeExtendedDestroy(getCleanupKind(DtorKind), DeclPtr,
5359 E->getType(), getDestroyer(DtorKind),
5360 DtorKind & EHCleanup);
5361
5362 return Result;
5363 }
5364
EmitInitListLValue(const InitListExpr * E)5365 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
5366 if (!E->isGLValue())
5367 // Initializing an aggregate temporary in C++11: T{...}.
5368 return EmitAggExprToLValue(E);
5369
5370 // An lvalue initializer list must be initializing a reference.
5371 assert(E->isTransparent() && "non-transparent glvalue init list");
5372 return EmitLValue(E->getInit(0));
5373 }
5374
5375 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
5376 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
5377 /// LValue is returned and the current block has been terminated.
EmitLValueOrThrowExpression(CodeGenFunction & CGF,const Expr * Operand)5378 static std::optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
5379 const Expr *Operand) {
5380 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
5381 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
5382 return std::nullopt;
5383 }
5384
5385 return CGF.EmitLValue(Operand);
5386 }
5387
5388 namespace {
5389 // Handle the case where the condition is a constant evaluatable simple integer,
5390 // which means we don't have to separately handle the true/false blocks.
HandleConditionalOperatorLValueSimpleCase(CodeGenFunction & CGF,const AbstractConditionalOperator * E)5391 std::optional<LValue> HandleConditionalOperatorLValueSimpleCase(
5392 CodeGenFunction &CGF, const AbstractConditionalOperator *E) {
5393 const Expr *condExpr = E->getCond();
5394 bool CondExprBool;
5395 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
5396 const Expr *Live = E->getTrueExpr(), *Dead = E->getFalseExpr();
5397 if (!CondExprBool)
5398 std::swap(Live, Dead);
5399
5400 if (!CGF.ContainsLabel(Dead)) {
5401 // If the true case is live, we need to track its region.
5402 if (CondExprBool)
5403 CGF.incrementProfileCounter(E);
5404 CGF.markStmtMaybeUsed(Dead);
5405 // If a throw expression we emit it and return an undefined lvalue
5406 // because it can't be used.
5407 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Live->IgnoreParens())) {
5408 CGF.EmitCXXThrowExpr(ThrowExpr);
5409 llvm::Type *ElemTy = CGF.ConvertType(Dead->getType());
5410 llvm::Type *Ty = CGF.UnqualPtrTy;
5411 return CGF.MakeAddrLValue(
5412 Address(llvm::UndefValue::get(Ty), ElemTy, CharUnits::One()),
5413 Dead->getType());
5414 }
5415 return CGF.EmitLValue(Live);
5416 }
5417 }
5418 return std::nullopt;
5419 }
5420 struct ConditionalInfo {
5421 llvm::BasicBlock *lhsBlock, *rhsBlock;
5422 std::optional<LValue> LHS, RHS;
5423 };
5424
5425 // Create and generate the 3 blocks for a conditional operator.
5426 // Leaves the 'current block' in the continuation basic block.
5427 template<typename FuncTy>
EmitConditionalBlocks(CodeGenFunction & CGF,const AbstractConditionalOperator * E,const FuncTy & BranchGenFunc)5428 ConditionalInfo EmitConditionalBlocks(CodeGenFunction &CGF,
5429 const AbstractConditionalOperator *E,
5430 const FuncTy &BranchGenFunc) {
5431 ConditionalInfo Info{CGF.createBasicBlock("cond.true"),
5432 CGF.createBasicBlock("cond.false"), std::nullopt,
5433 std::nullopt};
5434 llvm::BasicBlock *endBlock = CGF.createBasicBlock("cond.end");
5435
5436 CodeGenFunction::ConditionalEvaluation eval(CGF);
5437 CGF.EmitBranchOnBoolExpr(E->getCond(), Info.lhsBlock, Info.rhsBlock,
5438 CGF.getProfileCount(E));
5439
5440 // Any temporaries created here are conditional.
5441 CGF.EmitBlock(Info.lhsBlock);
5442 CGF.incrementProfileCounter(E);
5443 eval.begin(CGF);
5444 Info.LHS = BranchGenFunc(CGF, E->getTrueExpr());
5445 eval.end(CGF);
5446 Info.lhsBlock = CGF.Builder.GetInsertBlock();
5447
5448 if (Info.LHS)
5449 CGF.Builder.CreateBr(endBlock);
5450
5451 // Any temporaries created here are conditional.
5452 CGF.EmitBlock(Info.rhsBlock);
5453 eval.begin(CGF);
5454 Info.RHS = BranchGenFunc(CGF, E->getFalseExpr());
5455 eval.end(CGF);
5456 Info.rhsBlock = CGF.Builder.GetInsertBlock();
5457 CGF.EmitBlock(endBlock);
5458
5459 return Info;
5460 }
5461 } // namespace
5462
EmitIgnoredConditionalOperator(const AbstractConditionalOperator * E)5463 void CodeGenFunction::EmitIgnoredConditionalOperator(
5464 const AbstractConditionalOperator *E) {
5465 if (!E->isGLValue()) {
5466 // ?: here should be an aggregate.
5467 assert(hasAggregateEvaluationKind(E->getType()) &&
5468 "Unexpected conditional operator!");
5469 return (void)EmitAggExprToLValue(E);
5470 }
5471
5472 OpaqueValueMapping binding(*this, E);
5473 if (HandleConditionalOperatorLValueSimpleCase(*this, E))
5474 return;
5475
5476 EmitConditionalBlocks(*this, E, [](CodeGenFunction &CGF, const Expr *E) {
5477 CGF.EmitIgnoredExpr(E);
5478 return LValue{};
5479 });
5480 }
EmitConditionalOperatorLValue(const AbstractConditionalOperator * expr)5481 LValue CodeGenFunction::EmitConditionalOperatorLValue(
5482 const AbstractConditionalOperator *expr) {
5483 if (!expr->isGLValue()) {
5484 // ?: here should be an aggregate.
5485 assert(hasAggregateEvaluationKind(expr->getType()) &&
5486 "Unexpected conditional operator!");
5487 return EmitAggExprToLValue(expr);
5488 }
5489
5490 OpaqueValueMapping binding(*this, expr);
5491 if (std::optional<LValue> Res =
5492 HandleConditionalOperatorLValueSimpleCase(*this, expr))
5493 return *Res;
5494
5495 ConditionalInfo Info = EmitConditionalBlocks(
5496 *this, expr, [](CodeGenFunction &CGF, const Expr *E) {
5497 return EmitLValueOrThrowExpression(CGF, E);
5498 });
5499
5500 if ((Info.LHS && !Info.LHS->isSimple()) ||
5501 (Info.RHS && !Info.RHS->isSimple()))
5502 return EmitUnsupportedLValue(expr, "conditional operator");
5503
5504 if (Info.LHS && Info.RHS) {
5505 Address lhsAddr = Info.LHS->getAddress();
5506 Address rhsAddr = Info.RHS->getAddress();
5507 Address result = mergeAddressesInConditionalExpr(
5508 lhsAddr, rhsAddr, Info.lhsBlock, Info.rhsBlock,
5509 Builder.GetInsertBlock(), expr->getType());
5510 AlignmentSource alignSource =
5511 std::max(Info.LHS->getBaseInfo().getAlignmentSource(),
5512 Info.RHS->getBaseInfo().getAlignmentSource());
5513 TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForConditionalOperator(
5514 Info.LHS->getTBAAInfo(), Info.RHS->getTBAAInfo());
5515 return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
5516 TBAAInfo);
5517 } else {
5518 assert((Info.LHS || Info.RHS) &&
5519 "both operands of glvalue conditional are throw-expressions?");
5520 return Info.LHS ? *Info.LHS : *Info.RHS;
5521 }
5522 }
5523
5524 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
5525 /// type. If the cast is to a reference, we can have the usual lvalue result,
5526 /// otherwise if a cast is needed by the code generator in an lvalue context,
5527 /// then it must mean that we need the address of an aggregate in order to
5528 /// access one of its members. This can happen for all the reasons that casts
5529 /// are permitted with aggregate result, including noop aggregate casts, and
5530 /// cast from scalar to union.
EmitCastLValue(const CastExpr * E)5531 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
5532 switch (E->getCastKind()) {
5533 case CK_ToVoid:
5534 case CK_BitCast:
5535 case CK_LValueToRValueBitCast:
5536 case CK_ArrayToPointerDecay:
5537 case CK_FunctionToPointerDecay:
5538 case CK_NullToMemberPointer:
5539 case CK_NullToPointer:
5540 case CK_IntegralToPointer:
5541 case CK_PointerToIntegral:
5542 case CK_PointerToBoolean:
5543 case CK_IntegralCast:
5544 case CK_BooleanToSignedIntegral:
5545 case CK_IntegralToBoolean:
5546 case CK_IntegralToFloating:
5547 case CK_FloatingToIntegral:
5548 case CK_FloatingToBoolean:
5549 case CK_FloatingCast:
5550 case CK_FloatingRealToComplex:
5551 case CK_FloatingComplexToReal:
5552 case CK_FloatingComplexToBoolean:
5553 case CK_FloatingComplexCast:
5554 case CK_FloatingComplexToIntegralComplex:
5555 case CK_IntegralRealToComplex:
5556 case CK_IntegralComplexToReal:
5557 case CK_IntegralComplexToBoolean:
5558 case CK_IntegralComplexCast:
5559 case CK_IntegralComplexToFloatingComplex:
5560 case CK_DerivedToBaseMemberPointer:
5561 case CK_BaseToDerivedMemberPointer:
5562 case CK_MemberPointerToBoolean:
5563 case CK_ReinterpretMemberPointer:
5564 case CK_AnyPointerToBlockPointerCast:
5565 case CK_ARCProduceObject:
5566 case CK_ARCConsumeObject:
5567 case CK_ARCReclaimReturnedObject:
5568 case CK_ARCExtendBlockObject:
5569 case CK_CopyAndAutoreleaseBlockObject:
5570 case CK_IntToOCLSampler:
5571 case CK_FloatingToFixedPoint:
5572 case CK_FixedPointToFloating:
5573 case CK_FixedPointCast:
5574 case CK_FixedPointToBoolean:
5575 case CK_FixedPointToIntegral:
5576 case CK_IntegralToFixedPoint:
5577 case CK_MatrixCast:
5578 case CK_HLSLVectorTruncation:
5579 case CK_HLSLArrayRValue:
5580 case CK_HLSLElementwiseCast:
5581 case CK_HLSLAggregateSplatCast:
5582 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
5583
5584 case CK_Dependent:
5585 llvm_unreachable("dependent cast kind in IR gen!");
5586
5587 case CK_BuiltinFnToFnPtr:
5588 llvm_unreachable("builtin functions are handled elsewhere");
5589
5590 // These are never l-values; just use the aggregate emission code.
5591 case CK_NonAtomicToAtomic:
5592 case CK_AtomicToNonAtomic:
5593 return EmitAggExprToLValue(E);
5594
5595 case CK_Dynamic: {
5596 LValue LV = EmitLValue(E->getSubExpr());
5597 Address V = LV.getAddress();
5598 const auto *DCE = cast<CXXDynamicCastExpr>(E);
5599 return MakeNaturalAlignRawAddrLValue(EmitDynamicCast(V, DCE), E->getType());
5600 }
5601
5602 case CK_ConstructorConversion:
5603 case CK_UserDefinedConversion:
5604 case CK_CPointerToObjCPointerCast:
5605 case CK_BlockPointerToObjCPointerCast:
5606 case CK_LValueToRValue:
5607 return EmitLValue(E->getSubExpr());
5608
5609 case CK_NoOp: {
5610 // CK_NoOp can model a qualification conversion, which can remove an array
5611 // bound and change the IR type.
5612 // FIXME: Once pointee types are removed from IR, remove this.
5613 LValue LV = EmitLValue(E->getSubExpr());
5614 // Propagate the volatile qualifer to LValue, if exist in E.
5615 if (E->changesVolatileQualification())
5616 LV.getQuals() = E->getType().getQualifiers();
5617 if (LV.isSimple()) {
5618 Address V = LV.getAddress();
5619 if (V.isValid()) {
5620 llvm::Type *T = ConvertTypeForMem(E->getType());
5621 if (V.getElementType() != T)
5622 LV.setAddress(V.withElementType(T));
5623 }
5624 }
5625 return LV;
5626 }
5627
5628 case CK_UncheckedDerivedToBase:
5629 case CK_DerivedToBase: {
5630 const auto *DerivedClassTy =
5631 E->getSubExpr()->getType()->castAs<RecordType>();
5632 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
5633
5634 LValue LV = EmitLValue(E->getSubExpr());
5635 Address This = LV.getAddress();
5636
5637 // Perform the derived-to-base conversion
5638 Address Base = GetAddressOfBaseClass(
5639 This, DerivedClassDecl, E->path_begin(), E->path_end(),
5640 /*NullCheckValue=*/false, E->getExprLoc());
5641
5642 // TODO: Support accesses to members of base classes in TBAA. For now, we
5643 // conservatively pretend that the complete object is of the base class
5644 // type.
5645 return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
5646 CGM.getTBAAInfoForSubobject(LV, E->getType()));
5647 }
5648 case CK_ToUnion:
5649 return EmitAggExprToLValue(E);
5650 case CK_BaseToDerived: {
5651 const auto *DerivedClassTy = E->getType()->castAs<RecordType>();
5652 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
5653
5654 LValue LV = EmitLValue(E->getSubExpr());
5655
5656 // Perform the base-to-derived conversion
5657 Address Derived = GetAddressOfDerivedClass(
5658 LV.getAddress(), DerivedClassDecl, E->path_begin(), E->path_end(),
5659 /*NullCheckValue=*/false);
5660
5661 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
5662 // performed and the object is not of the derived type.
5663 if (sanitizePerformTypeCheck())
5664 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(), Derived,
5665 E->getType());
5666
5667 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
5668 EmitVTablePtrCheckForCast(E->getType(), Derived,
5669 /*MayBeNull=*/false, CFITCK_DerivedCast,
5670 E->getBeginLoc());
5671
5672 return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
5673 CGM.getTBAAInfoForSubobject(LV, E->getType()));
5674 }
5675 case CK_LValueBitCast: {
5676 // This must be a reinterpret_cast (or c-style equivalent).
5677 const auto *CE = cast<ExplicitCastExpr>(E);
5678
5679 CGM.EmitExplicitCastExprType(CE, this);
5680 LValue LV = EmitLValue(E->getSubExpr());
5681 Address V = LV.getAddress().withElementType(
5682 ConvertTypeForMem(CE->getTypeAsWritten()->getPointeeType()));
5683
5684 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
5685 EmitVTablePtrCheckForCast(E->getType(), V,
5686 /*MayBeNull=*/false, CFITCK_UnrelatedCast,
5687 E->getBeginLoc());
5688
5689 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
5690 CGM.getTBAAInfoForSubobject(LV, E->getType()));
5691 }
5692 case CK_AddressSpaceConversion: {
5693 LValue LV = EmitLValue(E->getSubExpr());
5694 QualType DestTy = getContext().getPointerType(E->getType());
5695 llvm::Value *V = getTargetHooks().performAddrSpaceCast(
5696 *this, LV.getPointer(*this),
5697 E->getSubExpr()->getType().getAddressSpace(), ConvertType(DestTy));
5698 return MakeAddrLValue(Address(V, ConvertTypeForMem(E->getType()),
5699 LV.getAddress().getAlignment()),
5700 E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
5701 }
5702 case CK_ObjCObjectLValueCast: {
5703 LValue LV = EmitLValue(E->getSubExpr());
5704 Address V = LV.getAddress().withElementType(ConvertType(E->getType()));
5705 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
5706 CGM.getTBAAInfoForSubobject(LV, E->getType()));
5707 }
5708 case CK_ZeroToOCLOpaqueType:
5709 llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
5710
5711 case CK_VectorSplat: {
5712 // LValue results of vector splats are only supported in HLSL.
5713 if (!getLangOpts().HLSL)
5714 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
5715 return EmitLValue(E->getSubExpr());
5716 }
5717 }
5718
5719 llvm_unreachable("Unhandled lvalue cast kind?");
5720 }
5721
EmitOpaqueValueLValue(const OpaqueValueExpr * e)5722 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
5723 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
5724 return getOrCreateOpaqueLValueMapping(e);
5725 }
5726
5727 std::pair<LValue, LValue>
EmitHLSLOutArgLValues(const HLSLOutArgExpr * E,QualType Ty)5728 CodeGenFunction::EmitHLSLOutArgLValues(const HLSLOutArgExpr *E, QualType Ty) {
5729 // Emitting the casted temporary through an opaque value.
5730 LValue BaseLV = EmitLValue(E->getArgLValue());
5731 OpaqueValueMappingData::bind(*this, E->getOpaqueArgLValue(), BaseLV);
5732
5733 QualType ExprTy = E->getType();
5734 Address OutTemp = CreateIRTemp(ExprTy);
5735 LValue TempLV = MakeAddrLValue(OutTemp, ExprTy);
5736
5737 if (E->isInOut())
5738 EmitInitializationToLValue(E->getCastedTemporary()->getSourceExpr(),
5739 TempLV);
5740
5741 OpaqueValueMappingData::bind(*this, E->getCastedTemporary(), TempLV);
5742 return std::make_pair(BaseLV, TempLV);
5743 }
5744
EmitHLSLOutArgExpr(const HLSLOutArgExpr * E,CallArgList & Args,QualType Ty)5745 LValue CodeGenFunction::EmitHLSLOutArgExpr(const HLSLOutArgExpr *E,
5746 CallArgList &Args, QualType Ty) {
5747
5748 auto [BaseLV, TempLV] = EmitHLSLOutArgLValues(E, Ty);
5749
5750 llvm::Value *Addr = TempLV.getAddress().getBasePointer();
5751 llvm::Type *ElTy = ConvertTypeForMem(TempLV.getType());
5752
5753 llvm::TypeSize Sz = CGM.getDataLayout().getTypeAllocSize(ElTy);
5754
5755 llvm::Value *LifetimeSize = EmitLifetimeStart(Sz, Addr);
5756
5757 Address TmpAddr(Addr, ElTy, TempLV.getAlignment());
5758 Args.addWriteback(BaseLV, TmpAddr, nullptr, E->getWritebackCast(),
5759 LifetimeSize);
5760 Args.add(RValue::get(TmpAddr, *this), Ty);
5761 return TempLV;
5762 }
5763
5764 LValue
getOrCreateOpaqueLValueMapping(const OpaqueValueExpr * e)5765 CodeGenFunction::getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e) {
5766 assert(OpaqueValueMapping::shouldBindAsLValue(e));
5767
5768 llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
5769 it = OpaqueLValues.find(e);
5770
5771 if (it != OpaqueLValues.end())
5772 return it->second;
5773
5774 assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
5775 return EmitLValue(e->getSourceExpr());
5776 }
5777
5778 RValue
getOrCreateOpaqueRValueMapping(const OpaqueValueExpr * e)5779 CodeGenFunction::getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e) {
5780 assert(!OpaqueValueMapping::shouldBindAsLValue(e));
5781
5782 llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
5783 it = OpaqueRValues.find(e);
5784
5785 if (it != OpaqueRValues.end())
5786 return it->second;
5787
5788 assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
5789 return EmitAnyExpr(e->getSourceExpr());
5790 }
5791
isOpaqueValueEmitted(const OpaqueValueExpr * E)5792 bool CodeGenFunction::isOpaqueValueEmitted(const OpaqueValueExpr *E) {
5793 if (OpaqueValueMapping::shouldBindAsLValue(E))
5794 return OpaqueLValues.contains(E);
5795 return OpaqueRValues.contains(E);
5796 }
5797
EmitRValueForField(LValue LV,const FieldDecl * FD,SourceLocation Loc)5798 RValue CodeGenFunction::EmitRValueForField(LValue LV,
5799 const FieldDecl *FD,
5800 SourceLocation Loc) {
5801 QualType FT = FD->getType();
5802 LValue FieldLV = EmitLValueForField(LV, FD);
5803 switch (getEvaluationKind(FT)) {
5804 case TEK_Complex:
5805 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
5806 case TEK_Aggregate:
5807 return FieldLV.asAggregateRValue();
5808 case TEK_Scalar:
5809 // This routine is used to load fields one-by-one to perform a copy, so
5810 // don't load reference fields.
5811 if (FD->getType()->isReferenceType())
5812 return RValue::get(FieldLV.getPointer(*this));
5813 // Call EmitLoadOfScalar except when the lvalue is a bitfield to emit a
5814 // primitive load.
5815 if (FieldLV.isBitField())
5816 return EmitLoadOfLValue(FieldLV, Loc);
5817 return RValue::get(EmitLoadOfScalar(FieldLV, Loc));
5818 }
5819 llvm_unreachable("bad evaluation kind");
5820 }
5821
5822 //===--------------------------------------------------------------------===//
5823 // Expression Emission
5824 //===--------------------------------------------------------------------===//
5825
EmitCallExpr(const CallExpr * E,ReturnValueSlot ReturnValue,llvm::CallBase ** CallOrInvoke)5826 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
5827 ReturnValueSlot ReturnValue,
5828 llvm::CallBase **CallOrInvoke) {
5829 llvm::CallBase *CallOrInvokeStorage;
5830 if (!CallOrInvoke) {
5831 CallOrInvoke = &CallOrInvokeStorage;
5832 }
5833
5834 auto AddCoroElideSafeOnExit = llvm::make_scope_exit([&] {
5835 if (E->isCoroElideSafe()) {
5836 auto *I = *CallOrInvoke;
5837 if (I)
5838 I->addFnAttr(llvm::Attribute::CoroElideSafe);
5839 }
5840 });
5841
5842 // Builtins never have block type.
5843 if (E->getCallee()->getType()->isBlockPointerType())
5844 return EmitBlockCallExpr(E, ReturnValue, CallOrInvoke);
5845
5846 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
5847 return EmitCXXMemberCallExpr(CE, ReturnValue, CallOrInvoke);
5848
5849 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
5850 return EmitCUDAKernelCallExpr(CE, ReturnValue, CallOrInvoke);
5851
5852 // A CXXOperatorCallExpr is created even for explicit object methods, but
5853 // these should be treated like static function call.
5854 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
5855 if (const auto *MD =
5856 dyn_cast_if_present<CXXMethodDecl>(CE->getCalleeDecl());
5857 MD && MD->isImplicitObjectMemberFunction())
5858 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue, CallOrInvoke);
5859
5860 CGCallee callee = EmitCallee(E->getCallee());
5861
5862 if (callee.isBuiltin()) {
5863 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
5864 E, ReturnValue);
5865 }
5866
5867 if (callee.isPseudoDestructor()) {
5868 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
5869 }
5870
5871 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue,
5872 /*Chain=*/nullptr, CallOrInvoke);
5873 }
5874
5875 /// Emit a CallExpr without considering whether it might be a subclass.
EmitSimpleCallExpr(const CallExpr * E,ReturnValueSlot ReturnValue,llvm::CallBase ** CallOrInvoke)5876 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
5877 ReturnValueSlot ReturnValue,
5878 llvm::CallBase **CallOrInvoke) {
5879 CGCallee Callee = EmitCallee(E->getCallee());
5880 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue,
5881 /*Chain=*/nullptr, CallOrInvoke);
5882 }
5883
5884 // Detect the unusual situation where an inline version is shadowed by a
5885 // non-inline version. In that case we should pick the external one
5886 // everywhere. That's GCC behavior too.
OnlyHasInlineBuiltinDeclaration(const FunctionDecl * FD)5887 static bool OnlyHasInlineBuiltinDeclaration(const FunctionDecl *FD) {
5888 for (const FunctionDecl *PD = FD; PD; PD = PD->getPreviousDecl())
5889 if (!PD->isInlineBuiltinDeclaration())
5890 return false;
5891 return true;
5892 }
5893
EmitDirectCallee(CodeGenFunction & CGF,GlobalDecl GD)5894 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, GlobalDecl GD) {
5895 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
5896
5897 if (auto builtinID = FD->getBuiltinID()) {
5898 std::string NoBuiltinFD = ("no-builtin-" + FD->getName()).str();
5899 std::string NoBuiltins = "no-builtins";
5900
5901 StringRef Ident = CGF.CGM.getMangledName(GD);
5902 std::string FDInlineName = (Ident + ".inline").str();
5903
5904 bool IsPredefinedLibFunction =
5905 CGF.getContext().BuiltinInfo.isPredefinedLibFunction(builtinID);
5906 bool HasAttributeNoBuiltin =
5907 CGF.CurFn->getAttributes().hasFnAttr(NoBuiltinFD) ||
5908 CGF.CurFn->getAttributes().hasFnAttr(NoBuiltins);
5909
5910 // When directing calling an inline builtin, call it through it's mangled
5911 // name to make it clear it's not the actual builtin.
5912 if (CGF.CurFn->getName() != FDInlineName &&
5913 OnlyHasInlineBuiltinDeclaration(FD)) {
5914 llvm::Constant *CalleePtr = CGF.CGM.getRawFunctionPointer(GD);
5915 llvm::Function *Fn = llvm::cast<llvm::Function>(CalleePtr);
5916 llvm::Module *M = Fn->getParent();
5917 llvm::Function *Clone = M->getFunction(FDInlineName);
5918 if (!Clone) {
5919 Clone = llvm::Function::Create(Fn->getFunctionType(),
5920 llvm::GlobalValue::InternalLinkage,
5921 Fn->getAddressSpace(), FDInlineName, M);
5922 Clone->addFnAttr(llvm::Attribute::AlwaysInline);
5923 }
5924 return CGCallee::forDirect(Clone, GD);
5925 }
5926
5927 // Replaceable builtins provide their own implementation of a builtin. If we
5928 // are in an inline builtin implementation, avoid trivial infinite
5929 // recursion. Honor __attribute__((no_builtin("foo"))) or
5930 // __attribute__((no_builtin)) on the current function unless foo is
5931 // not a predefined library function which means we must generate the
5932 // builtin no matter what.
5933 else if (!IsPredefinedLibFunction || !HasAttributeNoBuiltin)
5934 return CGCallee::forBuiltin(builtinID, FD);
5935 }
5936
5937 llvm::Constant *CalleePtr = CGF.CGM.getRawFunctionPointer(GD);
5938 if (CGF.CGM.getLangOpts().CUDA && !CGF.CGM.getLangOpts().CUDAIsDevice &&
5939 FD->hasAttr<CUDAGlobalAttr>())
5940 CalleePtr = CGF.CGM.getCUDARuntime().getKernelStub(
5941 cast<llvm::GlobalValue>(CalleePtr->stripPointerCasts()));
5942
5943 return CGCallee::forDirect(CalleePtr, GD);
5944 }
5945
getGlobalDeclForDirectCall(const FunctionDecl * FD)5946 static GlobalDecl getGlobalDeclForDirectCall(const FunctionDecl *FD) {
5947 if (DeviceKernelAttr::isOpenCLSpelling(FD->getAttr<DeviceKernelAttr>()))
5948 return GlobalDecl(FD, KernelReferenceKind::Stub);
5949 return GlobalDecl(FD);
5950 }
5951
EmitCallee(const Expr * E)5952 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
5953 E = E->IgnoreParens();
5954
5955 // Look through function-to-pointer decay.
5956 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
5957 if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
5958 ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
5959 return EmitCallee(ICE->getSubExpr());
5960 }
5961
5962 // Try to remember the original __ptrauth qualifier for loads of
5963 // function pointers.
5964 if (ICE->getCastKind() == CK_LValueToRValue) {
5965 const Expr *SubExpr = ICE->getSubExpr();
5966 if (const auto *PtrType = SubExpr->getType()->getAs<PointerType>()) {
5967 std::pair<llvm::Value *, CGPointerAuthInfo> Result =
5968 EmitOrigPointerRValue(E);
5969
5970 QualType FunctionType = PtrType->getPointeeType();
5971 assert(FunctionType->isFunctionType());
5972
5973 GlobalDecl GD;
5974 if (const auto *VD =
5975 dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee())) {
5976 GD = GlobalDecl(VD);
5977 }
5978 CGCalleeInfo CalleeInfo(FunctionType->getAs<FunctionProtoType>(), GD);
5979 CGCallee Callee(CalleeInfo, Result.first, Result.second);
5980 return Callee;
5981 }
5982 }
5983
5984 // Resolve direct calls.
5985 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
5986 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
5987 return EmitDirectCallee(*this, getGlobalDeclForDirectCall(FD));
5988 }
5989 } else if (auto ME = dyn_cast<MemberExpr>(E)) {
5990 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
5991 EmitIgnoredExpr(ME->getBase());
5992 return EmitDirectCallee(*this, FD);
5993 }
5994
5995 // Look through template substitutions.
5996 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
5997 return EmitCallee(NTTP->getReplacement());
5998
5999 // Treat pseudo-destructor calls differently.
6000 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
6001 return CGCallee::forPseudoDestructor(PDE);
6002 }
6003
6004 // Otherwise, we have an indirect reference.
6005 llvm::Value *calleePtr;
6006 QualType functionType;
6007 if (auto ptrType = E->getType()->getAs<PointerType>()) {
6008 calleePtr = EmitScalarExpr(E);
6009 functionType = ptrType->getPointeeType();
6010 } else {
6011 functionType = E->getType();
6012 calleePtr = EmitLValue(E, KnownNonNull).getPointer(*this);
6013 }
6014 assert(functionType->isFunctionType());
6015
6016 GlobalDecl GD;
6017 if (const auto *VD =
6018 dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
6019 GD = GlobalDecl(VD);
6020
6021 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
6022 CGPointerAuthInfo pointerAuth = CGM.getFunctionPointerAuthInfo(functionType);
6023 CGCallee callee(calleeInfo, calleePtr, pointerAuth);
6024 return callee;
6025 }
6026
EmitBinaryOperatorLValue(const BinaryOperator * E)6027 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
6028 // Comma expressions just emit their LHS then their RHS as an l-value.
6029 if (E->getOpcode() == BO_Comma) {
6030 EmitIgnoredExpr(E->getLHS());
6031 EnsureInsertPoint();
6032 return EmitLValue(E->getRHS());
6033 }
6034
6035 if (E->getOpcode() == BO_PtrMemD ||
6036 E->getOpcode() == BO_PtrMemI)
6037 return EmitPointerToDataMemberBinaryExpr(E);
6038
6039 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
6040
6041 // Create a Key Instructions source location atom group that covers both
6042 // LHS and RHS expressions. Nested RHS expressions may get subsequently
6043 // separately grouped (1 below):
6044 //
6045 // 1. `a = b = c` -> Two atoms.
6046 // 2. `x = new(1)` -> One atom (for both addr store and value store).
6047 // 3. Complex and agg assignment -> One atom.
6048 ApplyAtomGroup Grp(getDebugInfo());
6049
6050 // Note that in all of these cases, __block variables need the RHS
6051 // evaluated first just in case the variable gets moved by the RHS.
6052
6053 switch (getEvaluationKind(E->getType())) {
6054 case TEK_Scalar: {
6055 if (PointerAuthQualifier PtrAuth =
6056 E->getLHS()->getType().getPointerAuth()) {
6057 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
6058 LValue CopiedLV = LV;
6059 CopiedLV.getQuals().removePointerAuth();
6060 llvm::Value *RV =
6061 EmitPointerAuthQualify(PtrAuth, E->getRHS(), CopiedLV.getAddress());
6062 EmitNullabilityCheck(CopiedLV, RV, E->getExprLoc());
6063 EmitStoreThroughLValue(RValue::get(RV), CopiedLV);
6064 return LV;
6065 }
6066
6067 switch (E->getLHS()->getType().getObjCLifetime()) {
6068 case Qualifiers::OCL_Strong:
6069 return EmitARCStoreStrong(E, /*ignored*/ false).first;
6070
6071 case Qualifiers::OCL_Autoreleasing:
6072 return EmitARCStoreAutoreleasing(E).first;
6073
6074 // No reason to do any of these differently.
6075 case Qualifiers::OCL_None:
6076 case Qualifiers::OCL_ExplicitNone:
6077 case Qualifiers::OCL_Weak:
6078 break;
6079 }
6080
6081 // TODO: Can we de-duplicate this code with the corresponding code in
6082 // CGExprScalar, similar to the way EmitCompoundAssignmentLValue works?
6083 RValue RV;
6084 llvm::Value *Previous = nullptr;
6085 QualType SrcType = E->getRHS()->getType();
6086 // Check if LHS is a bitfield, if RHS contains an implicit cast expression
6087 // we want to extract that value and potentially (if the bitfield sanitizer
6088 // is enabled) use it to check for an implicit conversion.
6089 if (E->getLHS()->refersToBitField()) {
6090 llvm::Value *RHS =
6091 EmitWithOriginalRHSBitfieldAssignment(E, &Previous, &SrcType);
6092 RV = RValue::get(RHS);
6093 } else
6094 RV = EmitAnyExpr(E->getRHS());
6095
6096 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
6097
6098 if (RV.isScalar())
6099 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
6100
6101 if (LV.isBitField()) {
6102 llvm::Value *Result = nullptr;
6103 // If bitfield sanitizers are enabled we want to use the result
6104 // to check whether a truncation or sign change has occurred.
6105 if (SanOpts.has(SanitizerKind::ImplicitBitfieldConversion))
6106 EmitStoreThroughBitfieldLValue(RV, LV, &Result);
6107 else
6108 EmitStoreThroughBitfieldLValue(RV, LV);
6109
6110 // If the expression contained an implicit conversion, make sure
6111 // to use the value before the scalar conversion.
6112 llvm::Value *Src = Previous ? Previous : RV.getScalarVal();
6113 QualType DstType = E->getLHS()->getType();
6114 EmitBitfieldConversionCheck(Src, SrcType, Result, DstType,
6115 LV.getBitFieldInfo(), E->getExprLoc());
6116 } else
6117 EmitStoreThroughLValue(RV, LV);
6118
6119 if (getLangOpts().OpenMP)
6120 CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this,
6121 E->getLHS());
6122 return LV;
6123 }
6124
6125 case TEK_Complex:
6126 return EmitComplexAssignmentLValue(E);
6127
6128 case TEK_Aggregate:
6129 // If the lang opt is HLSL and the LHS is a constant array
6130 // then we are performing a copy assignment and call a special
6131 // function because EmitAggExprToLValue emits to a temporary LValue
6132 if (getLangOpts().HLSL && E->getLHS()->getType()->isConstantArrayType())
6133 return EmitHLSLArrayAssignLValue(E);
6134
6135 return EmitAggExprToLValue(E);
6136 }
6137 llvm_unreachable("bad evaluation kind");
6138 }
6139
6140 // This function implements trivial copy assignment for HLSL's
6141 // assignable constant arrays.
EmitHLSLArrayAssignLValue(const BinaryOperator * E)6142 LValue CodeGenFunction::EmitHLSLArrayAssignLValue(const BinaryOperator *E) {
6143 // Don't emit an LValue for the RHS because it might not be an LValue
6144 LValue LHS = EmitLValue(E->getLHS());
6145 // In C the RHS of an assignment operator is an RValue.
6146 // EmitAggregateAssign takes anan LValue for the RHS. Instead we can call
6147 // EmitInitializationToLValue to emit an RValue into an LValue.
6148 EmitInitializationToLValue(E->getRHS(), LHS);
6149 return LHS;
6150 }
6151
EmitCallExprLValue(const CallExpr * E,llvm::CallBase ** CallOrInvoke)6152 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E,
6153 llvm::CallBase **CallOrInvoke) {
6154 RValue RV = EmitCallExpr(E, ReturnValueSlot(), CallOrInvoke);
6155
6156 if (!RV.isScalar())
6157 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
6158 AlignmentSource::Decl);
6159
6160 assert(E->getCallReturnType(getContext())->isReferenceType() &&
6161 "Can't have a scalar return unless the return type is a "
6162 "reference type!");
6163
6164 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
6165 }
6166
EmitVAArgExprLValue(const VAArgExpr * E)6167 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
6168 // FIXME: This shouldn't require another copy.
6169 return EmitAggExprToLValue(E);
6170 }
6171
EmitCXXConstructLValue(const CXXConstructExpr * E)6172 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
6173 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
6174 && "binding l-value to type which needs a temporary");
6175 AggValueSlot Slot = CreateAggTemp(E->getType());
6176 EmitCXXConstructExpr(E, Slot);
6177 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
6178 }
6179
6180 LValue
EmitCXXTypeidLValue(const CXXTypeidExpr * E)6181 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
6182 return MakeNaturalAlignRawAddrLValue(EmitCXXTypeidExpr(E), E->getType());
6183 }
6184
EmitCXXUuidofExpr(const CXXUuidofExpr * E)6185 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
6186 return CGM.GetAddrOfMSGuidDecl(E->getGuidDecl())
6187 .withElementType(ConvertType(E->getType()));
6188 }
6189
EmitCXXUuidofLValue(const CXXUuidofExpr * E)6190 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
6191 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
6192 AlignmentSource::Decl);
6193 }
6194
6195 LValue
EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr * E)6196 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
6197 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
6198 Slot.setExternallyDestructed();
6199 EmitAggExpr(E->getSubExpr(), Slot);
6200 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
6201 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
6202 }
6203
EmitObjCMessageExprLValue(const ObjCMessageExpr * E)6204 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
6205 RValue RV = EmitObjCMessageExpr(E);
6206
6207 if (!RV.isScalar())
6208 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
6209 AlignmentSource::Decl);
6210
6211 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
6212 "Can't have a scalar return unless the return type is a "
6213 "reference type!");
6214
6215 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
6216 }
6217
EmitObjCSelectorLValue(const ObjCSelectorExpr * E)6218 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
6219 Address V =
6220 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
6221 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
6222 }
6223
EmitIvarOffset(const ObjCInterfaceDecl * Interface,const ObjCIvarDecl * Ivar)6224 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
6225 const ObjCIvarDecl *Ivar) {
6226 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
6227 }
6228
6229 llvm::Value *
EmitIvarOffsetAsPointerDiff(const ObjCInterfaceDecl * Interface,const ObjCIvarDecl * Ivar)6230 CodeGenFunction::EmitIvarOffsetAsPointerDiff(const ObjCInterfaceDecl *Interface,
6231 const ObjCIvarDecl *Ivar) {
6232 llvm::Value *OffsetValue = EmitIvarOffset(Interface, Ivar);
6233 QualType PointerDiffType = getContext().getPointerDiffType();
6234 return Builder.CreateZExtOrTrunc(OffsetValue,
6235 getTypes().ConvertType(PointerDiffType));
6236 }
6237
EmitLValueForIvar(QualType ObjectTy,llvm::Value * BaseValue,const ObjCIvarDecl * Ivar,unsigned CVRQualifiers)6238 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
6239 llvm::Value *BaseValue,
6240 const ObjCIvarDecl *Ivar,
6241 unsigned CVRQualifiers) {
6242 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
6243 Ivar, CVRQualifiers);
6244 }
6245
EmitObjCIvarRefLValue(const ObjCIvarRefExpr * E)6246 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
6247 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
6248 llvm::Value *BaseValue = nullptr;
6249 const Expr *BaseExpr = E->getBase();
6250 Qualifiers BaseQuals;
6251 QualType ObjectTy;
6252 if (E->isArrow()) {
6253 BaseValue = EmitScalarExpr(BaseExpr);
6254 ObjectTy = BaseExpr->getType()->getPointeeType();
6255 BaseQuals = ObjectTy.getQualifiers();
6256 } else {
6257 LValue BaseLV = EmitLValue(BaseExpr);
6258 BaseValue = BaseLV.getPointer(*this);
6259 ObjectTy = BaseExpr->getType();
6260 BaseQuals = ObjectTy.getQualifiers();
6261 }
6262
6263 LValue LV =
6264 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
6265 BaseQuals.getCVRQualifiers());
6266 setObjCGCLValueClass(getContext(), E, LV);
6267 return LV;
6268 }
6269
EmitStmtExprLValue(const StmtExpr * E)6270 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
6271 // Can only get l-value for message expression returning aggregate type
6272 RValue RV = EmitAnyExprToTemp(E);
6273 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
6274 AlignmentSource::Decl);
6275 }
6276
EmitCall(QualType CalleeType,const CGCallee & OrigCallee,const CallExpr * E,ReturnValueSlot ReturnValue,llvm::Value * Chain,llvm::CallBase ** CallOrInvoke,CGFunctionInfo const ** ResolvedFnInfo)6277 RValue CodeGenFunction::EmitCall(QualType CalleeType,
6278 const CGCallee &OrigCallee, const CallExpr *E,
6279 ReturnValueSlot ReturnValue,
6280 llvm::Value *Chain,
6281 llvm::CallBase **CallOrInvoke,
6282 CGFunctionInfo const **ResolvedFnInfo) {
6283 // Get the actual function type. The callee type will always be a pointer to
6284 // function type or a block pointer type.
6285 assert(CalleeType->isFunctionPointerType() &&
6286 "Call must have function pointer type!");
6287
6288 const Decl *TargetDecl =
6289 OrigCallee.getAbstractInfo().getCalleeDecl().getDecl();
6290
6291 assert((!isa_and_present<FunctionDecl>(TargetDecl) ||
6292 !cast<FunctionDecl>(TargetDecl)->isImmediateFunction()) &&
6293 "trying to emit a call to an immediate function");
6294
6295 CalleeType = getContext().getCanonicalType(CalleeType);
6296
6297 auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
6298
6299 CGCallee Callee = OrigCallee;
6300
6301 if (SanOpts.has(SanitizerKind::Function) &&
6302 (!TargetDecl || !isa<FunctionDecl>(TargetDecl)) &&
6303 !isa<FunctionNoProtoType>(PointeeType)) {
6304 if (llvm::Constant *PrefixSig =
6305 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
6306 auto CheckOrdinal = SanitizerKind::SO_Function;
6307 auto CheckHandler = SanitizerHandler::FunctionTypeMismatch;
6308 SanitizerDebugLocation SanScope(this, {CheckOrdinal}, CheckHandler);
6309 auto *TypeHash = getUBSanFunctionTypeHash(PointeeType);
6310
6311 llvm::Type *PrefixSigType = PrefixSig->getType();
6312 llvm::StructType *PrefixStructTy = llvm::StructType::get(
6313 CGM.getLLVMContext(), {PrefixSigType, Int32Ty}, /*isPacked=*/true);
6314
6315 llvm::Value *CalleePtr = Callee.getFunctionPointer();
6316 if (CGM.getCodeGenOpts().PointerAuth.FunctionPointers) {
6317 // Use raw pointer since we are using the callee pointer as data here.
6318 Address Addr =
6319 Address(CalleePtr, CalleePtr->getType(),
6320 CharUnits::fromQuantity(
6321 CalleePtr->getPointerAlignment(CGM.getDataLayout())),
6322 Callee.getPointerAuthInfo(), nullptr);
6323 CalleePtr = Addr.emitRawPointer(*this);
6324 }
6325
6326 // On 32-bit Arm, the low bit of a function pointer indicates whether
6327 // it's using the Arm or Thumb instruction set. The actual first
6328 // instruction lives at the same address either way, so we must clear
6329 // that low bit before using the function address to find the prefix
6330 // structure.
6331 //
6332 // This applies to both Arm and Thumb target triples, because
6333 // either one could be used in an interworking context where it
6334 // might be passed function pointers of both types.
6335 llvm::Value *AlignedCalleePtr;
6336 if (CGM.getTriple().isARM() || CGM.getTriple().isThumb()) {
6337 llvm::Value *CalleeAddress =
6338 Builder.CreatePtrToInt(CalleePtr, IntPtrTy);
6339 llvm::Value *Mask = llvm::ConstantInt::get(IntPtrTy, ~1);
6340 llvm::Value *AlignedCalleeAddress =
6341 Builder.CreateAnd(CalleeAddress, Mask);
6342 AlignedCalleePtr =
6343 Builder.CreateIntToPtr(AlignedCalleeAddress, CalleePtr->getType());
6344 } else {
6345 AlignedCalleePtr = CalleePtr;
6346 }
6347
6348 llvm::Value *CalleePrefixStruct = AlignedCalleePtr;
6349 llvm::Value *CalleeSigPtr =
6350 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, -1, 0);
6351 llvm::Value *CalleeSig =
6352 Builder.CreateAlignedLoad(PrefixSigType, CalleeSigPtr, getIntAlign());
6353 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
6354
6355 llvm::BasicBlock *Cont = createBasicBlock("cont");
6356 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
6357 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
6358
6359 EmitBlock(TypeCheck);
6360 llvm::Value *CalleeTypeHash = Builder.CreateAlignedLoad(
6361 Int32Ty,
6362 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, -1, 1),
6363 getPointerAlign());
6364 llvm::Value *CalleeTypeHashMatch =
6365 Builder.CreateICmpEQ(CalleeTypeHash, TypeHash);
6366 llvm::Constant *StaticData[] = {EmitCheckSourceLocation(E->getBeginLoc()),
6367 EmitCheckTypeDescriptor(CalleeType)};
6368 EmitCheck(std::make_pair(CalleeTypeHashMatch, CheckOrdinal), CheckHandler,
6369 StaticData, {CalleePtr});
6370
6371 Builder.CreateBr(Cont);
6372 EmitBlock(Cont);
6373 }
6374 }
6375
6376 const auto *FnType = cast<FunctionType>(PointeeType);
6377
6378 if (const auto *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl);
6379 FD && DeviceKernelAttr::isOpenCLSpelling(FD->getAttr<DeviceKernelAttr>()))
6380 CGM.getTargetCodeGenInfo().setOCLKernelStubCallingConvention(FnType);
6381
6382 bool CFIUnchecked =
6383 CalleeType->hasPointeeToToCFIUncheckedCalleeFunctionType();
6384
6385 // If we are checking indirect calls and this call is indirect, check that the
6386 // function pointer is a member of the bit set for the function type.
6387 if (SanOpts.has(SanitizerKind::CFIICall) &&
6388 (!TargetDecl || !isa<FunctionDecl>(TargetDecl)) && !CFIUnchecked) {
6389 auto CheckOrdinal = SanitizerKind::SO_CFIICall;
6390 auto CheckHandler = SanitizerHandler::CFICheckFail;
6391 SanitizerDebugLocation SanScope(this, {CheckOrdinal}, CheckHandler);
6392 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
6393
6394 llvm::Metadata *MD;
6395 if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
6396 MD = CGM.CreateMetadataIdentifierGeneralized(QualType(FnType, 0));
6397 else
6398 MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
6399
6400 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
6401
6402 llvm::Value *CalleePtr = Callee.getFunctionPointer();
6403 llvm::Value *TypeTest = Builder.CreateCall(
6404 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CalleePtr, TypeId});
6405
6406 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
6407 llvm::Constant *StaticData[] = {
6408 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
6409 EmitCheckSourceLocation(E->getBeginLoc()),
6410 EmitCheckTypeDescriptor(QualType(FnType, 0)),
6411 };
6412 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
6413 EmitCfiSlowPathCheck(CheckOrdinal, TypeTest, CrossDsoTypeId, CalleePtr,
6414 StaticData);
6415 } else {
6416 EmitCheck(std::make_pair(TypeTest, CheckOrdinal), CheckHandler,
6417 StaticData, {CalleePtr, llvm::UndefValue::get(IntPtrTy)});
6418 }
6419 }
6420
6421 CallArgList Args;
6422 if (Chain)
6423 Args.add(RValue::get(Chain), CGM.getContext().VoidPtrTy);
6424
6425 // C++17 requires that we evaluate arguments to a call using assignment syntax
6426 // right-to-left, and that we evaluate arguments to certain other operators
6427 // left-to-right. Note that we allow this to override the order dictated by
6428 // the calling convention on the MS ABI, which means that parameter
6429 // destruction order is not necessarily reverse construction order.
6430 // FIXME: Revisit this based on C++ committee response to unimplementability.
6431 EvaluationOrder Order = EvaluationOrder::Default;
6432 bool StaticOperator = false;
6433 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
6434 if (OCE->isAssignmentOp())
6435 Order = EvaluationOrder::ForceRightToLeft;
6436 else {
6437 switch (OCE->getOperator()) {
6438 case OO_LessLess:
6439 case OO_GreaterGreater:
6440 case OO_AmpAmp:
6441 case OO_PipePipe:
6442 case OO_Comma:
6443 case OO_ArrowStar:
6444 Order = EvaluationOrder::ForceLeftToRight;
6445 break;
6446 default:
6447 break;
6448 }
6449 }
6450
6451 if (const auto *MD =
6452 dyn_cast_if_present<CXXMethodDecl>(OCE->getCalleeDecl());
6453 MD && MD->isStatic())
6454 StaticOperator = true;
6455 }
6456
6457 auto Arguments = E->arguments();
6458 if (StaticOperator) {
6459 // If we're calling a static operator, we need to emit the object argument
6460 // and ignore it.
6461 EmitIgnoredExpr(E->getArg(0));
6462 Arguments = drop_begin(Arguments, 1);
6463 }
6464 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), Arguments,
6465 E->getDirectCallee(), /*ParamsToSkip=*/0, Order);
6466
6467 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
6468 Args, FnType, /*ChainCall=*/Chain);
6469
6470 if (ResolvedFnInfo)
6471 *ResolvedFnInfo = &FnInfo;
6472
6473 // HIP function pointer contains kernel handle when it is used in triple
6474 // chevron. The kernel stub needs to be loaded from kernel handle and used
6475 // as callee.
6476 if (CGM.getLangOpts().HIP && !CGM.getLangOpts().CUDAIsDevice &&
6477 isa<CUDAKernelCallExpr>(E) &&
6478 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
6479 llvm::Value *Handle = Callee.getFunctionPointer();
6480 auto *Stub = Builder.CreateLoad(
6481 Address(Handle, Handle->getType(), CGM.getPointerAlign()));
6482 Callee.setFunctionPointer(Stub);
6483 }
6484 llvm::CallBase *LocalCallOrInvoke = nullptr;
6485 RValue Call = EmitCall(FnInfo, Callee, ReturnValue, Args, &LocalCallOrInvoke,
6486 E == MustTailCall, E->getExprLoc());
6487
6488 // Generate function declaration DISuprogram in order to be used
6489 // in debug info about call sites.
6490 if (CGDebugInfo *DI = getDebugInfo()) {
6491 if (auto *CalleeDecl = dyn_cast_or_null<FunctionDecl>(TargetDecl)) {
6492 FunctionArgList Args;
6493 QualType ResTy = BuildFunctionArgList(CalleeDecl, Args);
6494 DI->EmitFuncDeclForCallSite(LocalCallOrInvoke,
6495 DI->getFunctionType(CalleeDecl, ResTy, Args),
6496 CalleeDecl);
6497 }
6498 }
6499 if (CallOrInvoke)
6500 *CallOrInvoke = LocalCallOrInvoke;
6501
6502 return Call;
6503 }
6504
6505 LValue CodeGenFunction::
EmitPointerToDataMemberBinaryExpr(const BinaryOperator * E)6506 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
6507 Address BaseAddr = Address::invalid();
6508 if (E->getOpcode() == BO_PtrMemI) {
6509 BaseAddr = EmitPointerWithAlignment(E->getLHS());
6510 } else {
6511 BaseAddr = EmitLValue(E->getLHS()).getAddress();
6512 }
6513
6514 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
6515 const auto *MPT = E->getRHS()->getType()->castAs<MemberPointerType>();
6516
6517 LValueBaseInfo BaseInfo;
6518 TBAAAccessInfo TBAAInfo;
6519 bool IsInBounds = !getLangOpts().PointerOverflowDefined &&
6520 !isUnderlyingBasePointerConstantNull(E->getLHS());
6521 Address MemberAddr = EmitCXXMemberDataPointerAddress(
6522 E, BaseAddr, OffsetV, MPT, IsInBounds, &BaseInfo, &TBAAInfo);
6523
6524 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo);
6525 }
6526
6527 /// Given the address of a temporary variable, produce an r-value of
6528 /// its type.
convertTempToRValue(Address addr,QualType type,SourceLocation loc)6529 RValue CodeGenFunction::convertTempToRValue(Address addr,
6530 QualType type,
6531 SourceLocation loc) {
6532 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
6533 switch (getEvaluationKind(type)) {
6534 case TEK_Complex:
6535 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
6536 case TEK_Aggregate:
6537 return lvalue.asAggregateRValue();
6538 case TEK_Scalar:
6539 return RValue::get(EmitLoadOfScalar(lvalue, loc));
6540 }
6541 llvm_unreachable("bad evaluation kind");
6542 }
6543
SetFPAccuracy(llvm::Value * Val,float Accuracy)6544 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
6545 assert(Val->getType()->isFPOrFPVectorTy());
6546 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
6547 return;
6548
6549 llvm::MDBuilder MDHelper(getLLVMContext());
6550 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
6551
6552 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
6553 }
6554
SetSqrtFPAccuracy(llvm::Value * Val)6555 void CodeGenFunction::SetSqrtFPAccuracy(llvm::Value *Val) {
6556 llvm::Type *EltTy = Val->getType()->getScalarType();
6557 if (!EltTy->isFloatTy())
6558 return;
6559
6560 if ((getLangOpts().OpenCL &&
6561 !CGM.getCodeGenOpts().OpenCLCorrectlyRoundedDivSqrt) ||
6562 (getLangOpts().HIP && getLangOpts().CUDAIsDevice &&
6563 !CGM.getCodeGenOpts().HIPCorrectlyRoundedDivSqrt)) {
6564 // OpenCL v1.1 s7.4: minimum accuracy of single precision / is 3ulp
6565 //
6566 // OpenCL v1.2 s5.6.4.2: The -cl-fp32-correctly-rounded-divide-sqrt
6567 // build option allows an application to specify that single precision
6568 // floating-point divide (x/y and 1/x) and sqrt used in the program
6569 // source are correctly rounded.
6570 //
6571 // TODO: CUDA has a prec-sqrt flag
6572 SetFPAccuracy(Val, 3.0f);
6573 }
6574 }
6575
SetDivFPAccuracy(llvm::Value * Val)6576 void CodeGenFunction::SetDivFPAccuracy(llvm::Value *Val) {
6577 llvm::Type *EltTy = Val->getType()->getScalarType();
6578 if (!EltTy->isFloatTy())
6579 return;
6580
6581 if ((getLangOpts().OpenCL &&
6582 !CGM.getCodeGenOpts().OpenCLCorrectlyRoundedDivSqrt) ||
6583 (getLangOpts().HIP && getLangOpts().CUDAIsDevice &&
6584 !CGM.getCodeGenOpts().HIPCorrectlyRoundedDivSqrt)) {
6585 // OpenCL v1.1 s7.4: minimum accuracy of single precision / is 2.5ulp
6586 //
6587 // OpenCL v1.2 s5.6.4.2: The -cl-fp32-correctly-rounded-divide-sqrt
6588 // build option allows an application to specify that single precision
6589 // floating-point divide (x/y and 1/x) and sqrt used in the program
6590 // source are correctly rounded.
6591 //
6592 // TODO: CUDA has a prec-div flag
6593 SetFPAccuracy(Val, 2.5f);
6594 }
6595 }
6596
6597 namespace {
6598 struct LValueOrRValue {
6599 LValue LV;
6600 RValue RV;
6601 };
6602 }
6603
emitPseudoObjectExpr(CodeGenFunction & CGF,const PseudoObjectExpr * E,bool forLValue,AggValueSlot slot)6604 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
6605 const PseudoObjectExpr *E,
6606 bool forLValue,
6607 AggValueSlot slot) {
6608 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
6609
6610 // Find the result expression, if any.
6611 const Expr *resultExpr = E->getResultExpr();
6612 LValueOrRValue result;
6613
6614 for (PseudoObjectExpr::const_semantics_iterator
6615 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
6616 const Expr *semantic = *i;
6617
6618 // If this semantic expression is an opaque value, bind it
6619 // to the result of its source expression.
6620 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
6621 // Skip unique OVEs.
6622 if (ov->isUnique()) {
6623 assert(ov != resultExpr &&
6624 "A unique OVE cannot be used as the result expression");
6625 continue;
6626 }
6627
6628 // If this is the result expression, we may need to evaluate
6629 // directly into the slot.
6630 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
6631 OVMA opaqueData;
6632 if (ov == resultExpr && ov->isPRValue() && !forLValue &&
6633 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
6634 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
6635 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
6636 AlignmentSource::Decl);
6637 opaqueData = OVMA::bind(CGF, ov, LV);
6638 result.RV = slot.asRValue();
6639
6640 // Otherwise, emit as normal.
6641 } else {
6642 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
6643
6644 // If this is the result, also evaluate the result now.
6645 if (ov == resultExpr) {
6646 if (forLValue)
6647 result.LV = CGF.EmitLValue(ov);
6648 else
6649 result.RV = CGF.EmitAnyExpr(ov, slot);
6650 }
6651 }
6652
6653 opaques.push_back(opaqueData);
6654
6655 // Otherwise, if the expression is the result, evaluate it
6656 // and remember the result.
6657 } else if (semantic == resultExpr) {
6658 if (forLValue)
6659 result.LV = CGF.EmitLValue(semantic);
6660 else
6661 result.RV = CGF.EmitAnyExpr(semantic, slot);
6662
6663 // Otherwise, evaluate the expression in an ignored context.
6664 } else {
6665 CGF.EmitIgnoredExpr(semantic);
6666 }
6667 }
6668
6669 // Unbind all the opaques now.
6670 for (CodeGenFunction::OpaqueValueMappingData &opaque : opaques)
6671 opaque.unbind(CGF);
6672
6673 return result;
6674 }
6675
EmitPseudoObjectRValue(const PseudoObjectExpr * E,AggValueSlot slot)6676 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
6677 AggValueSlot slot) {
6678 return emitPseudoObjectExpr(*this, E, false, slot).RV;
6679 }
6680
EmitPseudoObjectLValue(const PseudoObjectExpr * E)6681 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
6682 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;
6683 }
6684
FlattenAccessAndType(Address Addr,QualType AddrType,SmallVectorImpl<std::pair<Address,llvm::Value * >> & AccessList,SmallVectorImpl<QualType> & FlatTypes)6685 void CodeGenFunction::FlattenAccessAndType(
6686 Address Addr, QualType AddrType,
6687 SmallVectorImpl<std::pair<Address, llvm::Value *>> &AccessList,
6688 SmallVectorImpl<QualType> &FlatTypes) {
6689 // WorkList is list of type we are processing + the Index List to access
6690 // the field of that type in Addr for use in a GEP
6691 llvm::SmallVector<std::pair<QualType, llvm::SmallVector<llvm::Value *, 4>>,
6692 16>
6693 WorkList;
6694 llvm::IntegerType *IdxTy = llvm::IntegerType::get(getLLVMContext(), 32);
6695 // Addr should be a pointer so we need to 'dereference' it
6696 WorkList.push_back({AddrType, {llvm::ConstantInt::get(IdxTy, 0)}});
6697
6698 while (!WorkList.empty()) {
6699 auto [T, IdxList] = WorkList.pop_back_val();
6700 T = T.getCanonicalType().getUnqualifiedType();
6701 assert(!isa<MatrixType>(T) && "Matrix types not yet supported in HLSL");
6702 if (const auto *CAT = dyn_cast<ConstantArrayType>(T)) {
6703 uint64_t Size = CAT->getZExtSize();
6704 for (int64_t I = Size - 1; I > -1; I--) {
6705 llvm::SmallVector<llvm::Value *, 4> IdxListCopy = IdxList;
6706 IdxListCopy.push_back(llvm::ConstantInt::get(IdxTy, I));
6707 WorkList.emplace_back(CAT->getElementType(), IdxListCopy);
6708 }
6709 } else if (const auto *RT = dyn_cast<RecordType>(T)) {
6710 const RecordDecl *Record = RT->getDecl();
6711 assert(!Record->isUnion() && "Union types not supported in flat cast.");
6712
6713 const CXXRecordDecl *CXXD = dyn_cast<CXXRecordDecl>(Record);
6714
6715 llvm::SmallVector<QualType, 16> FieldTypes;
6716 if (CXXD && CXXD->isStandardLayout())
6717 Record = CXXD->getStandardLayoutBaseWithFields();
6718
6719 // deal with potential base classes
6720 if (CXXD && !CXXD->isStandardLayout()) {
6721 for (auto &Base : CXXD->bases())
6722 FieldTypes.push_back(Base.getType());
6723 }
6724
6725 for (auto *FD : Record->fields())
6726 FieldTypes.push_back(FD->getType());
6727
6728 for (int64_t I = FieldTypes.size() - 1; I > -1; I--) {
6729 llvm::SmallVector<llvm::Value *, 4> IdxListCopy = IdxList;
6730 IdxListCopy.push_back(llvm::ConstantInt::get(IdxTy, I));
6731 WorkList.insert(WorkList.end(), {FieldTypes[I], IdxListCopy});
6732 }
6733 } else if (const auto *VT = dyn_cast<VectorType>(T)) {
6734 llvm::Type *LLVMT = ConvertTypeForMem(T);
6735 CharUnits Align = getContext().getTypeAlignInChars(T);
6736 Address GEP =
6737 Builder.CreateInBoundsGEP(Addr, IdxList, LLVMT, Align, "vector.gep");
6738 for (unsigned I = 0, E = VT->getNumElements(); I < E; I++) {
6739 llvm::Value *Idx = llvm::ConstantInt::get(IdxTy, I);
6740 // gep on vector fields is not recommended so combine gep with
6741 // extract/insert
6742 AccessList.emplace_back(GEP, Idx);
6743 FlatTypes.push_back(VT->getElementType());
6744 }
6745 } else {
6746 // a scalar/builtin type
6747 llvm::Type *LLVMT = ConvertTypeForMem(T);
6748 CharUnits Align = getContext().getTypeAlignInChars(T);
6749 Address GEP =
6750 Builder.CreateInBoundsGEP(Addr, IdxList, LLVMT, Align, "gep");
6751 AccessList.emplace_back(GEP, nullptr);
6752 FlatTypes.push_back(T);
6753 }
6754 }
6755 }
6756