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 "CGCUDARuntime.h"
14 #include "CGCXXABI.h"
15 #include "CGCall.h"
16 #include "CGCleanup.h"
17 #include "CGDebugInfo.h"
18 #include "CGObjCRuntime.h"
19 #include "CGOpenMPRuntime.h"
20 #include "CGRecordLayout.h"
21 #include "CodeGenFunction.h"
22 #include "CodeGenModule.h"
23 #include "ConstantEmitter.h"
24 #include "TargetInfo.h"
25 #include "clang/AST/ASTContext.h"
26 #include "clang/AST/Attr.h"
27 #include "clang/AST/DeclObjC.h"
28 #include "clang/AST/NSAPI.h"
29 #include "clang/AST/StmtVisitor.h"
30 #include "clang/Basic/Builtins.h"
31 #include "clang/Basic/CodeGenOptions.h"
32 #include "clang/Basic/SourceManager.h"
33 #include "llvm/ADT/Hashing.h"
34 #include "llvm/ADT/STLExtras.h"
35 #include "llvm/ADT/StringExtras.h"
36 #include "llvm/IR/DataLayout.h"
37 #include "llvm/IR/Intrinsics.h"
38 #include "llvm/IR/IntrinsicsWebAssembly.h"
39 #include "llvm/IR/LLVMContext.h"
40 #include "llvm/IR/MDBuilder.h"
41 #include "llvm/IR/MatrixBuilder.h"
42 #include "llvm/Passes/OptimizationLevel.h"
43 #include "llvm/Support/ConvertUTF.h"
44 #include "llvm/Support/MathExtras.h"
45 #include "llvm/Support/Path.h"
46 #include "llvm/Support/SaveAndRestore.h"
47 #include "llvm/Support/xxhash.h"
48 #include "llvm/Transforms/Utils/SanitizerStats.h"
49
50 #include <optional>
51 #include <string>
52
53 using namespace clang;
54 using namespace CodeGen;
55
56 // Experiment to make sanitizers easier to debug
57 static llvm::cl::opt<bool> ClSanitizeDebugDeoptimization(
58 "ubsan-unique-traps", llvm::cl::Optional,
59 llvm::cl::desc("Deoptimize traps for UBSAN so there is 1 trap per check"),
60 llvm::cl::init(false));
61
62 //===--------------------------------------------------------------------===//
63 // Miscellaneous Helper Methods
64 //===--------------------------------------------------------------------===//
65
66 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
67 /// block.
CreateTempAllocaWithoutCast(llvm::Type * Ty,CharUnits Align,const Twine & Name,llvm::Value * ArraySize)68 Address CodeGenFunction::CreateTempAllocaWithoutCast(llvm::Type *Ty,
69 CharUnits Align,
70 const Twine &Name,
71 llvm::Value *ArraySize) {
72 auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
73 Alloca->setAlignment(Align.getAsAlign());
74 return Address(Alloca, Ty, Align, KnownNonNull);
75 }
76
77 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
78 /// block. The alloca is casted to default address space if necessary.
CreateTempAlloca(llvm::Type * Ty,CharUnits Align,const Twine & Name,llvm::Value * ArraySize,Address * AllocaAddr)79 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
80 const Twine &Name,
81 llvm::Value *ArraySize,
82 Address *AllocaAddr) {
83 auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize);
84 if (AllocaAddr)
85 *AllocaAddr = Alloca;
86 llvm::Value *V = Alloca.getPointer();
87 // Alloca always returns a pointer in alloca address space, which may
88 // be different from the type defined by the language. For example,
89 // in C++ the auto variables are in the default address space. Therefore
90 // cast alloca to the default address space when necessary.
91 if (getASTAllocaAddressSpace() != LangAS::Default) {
92 auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
93 llvm::IRBuilderBase::InsertPointGuard IPG(Builder);
94 // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt,
95 // otherwise alloca is inserted at the current insertion point of the
96 // builder.
97 if (!ArraySize)
98 Builder.SetInsertPoint(getPostAllocaInsertPoint());
99 V = getTargetHooks().performAddrSpaceCast(
100 *this, V, getASTAllocaAddressSpace(), LangAS::Default,
101 Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
102 }
103
104 return Address(V, Ty, Align, KnownNonNull);
105 }
106
107 /// CreateTempAlloca - This creates an alloca and inserts it into the entry
108 /// block if \p ArraySize is nullptr, otherwise inserts it at the current
109 /// insertion point of the builder.
CreateTempAlloca(llvm::Type * Ty,const Twine & Name,llvm::Value * ArraySize)110 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
111 const Twine &Name,
112 llvm::Value *ArraySize) {
113 if (ArraySize)
114 return Builder.CreateAlloca(Ty, ArraySize, Name);
115 return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
116 ArraySize, Name, AllocaInsertPt);
117 }
118
119 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
120 /// default alignment of the corresponding LLVM type, which is *not*
121 /// guaranteed to be related in any way to the expected alignment of
122 /// an AST type that might have been lowered to Ty.
CreateDefaultAlignTempAlloca(llvm::Type * Ty,const Twine & Name)123 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty,
124 const Twine &Name) {
125 CharUnits Align =
126 CharUnits::fromQuantity(CGM.getDataLayout().getPrefTypeAlign(Ty));
127 return CreateTempAlloca(Ty, Align, Name);
128 }
129
CreateIRTemp(QualType Ty,const Twine & Name)130 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
131 CharUnits Align = getContext().getTypeAlignInChars(Ty);
132 return CreateTempAlloca(ConvertType(Ty), Align, Name);
133 }
134
CreateMemTemp(QualType Ty,const Twine & Name,Address * Alloca)135 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name,
136 Address *Alloca) {
137 // FIXME: Should we prefer the preferred type alignment here?
138 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
139 }
140
CreateMemTemp(QualType Ty,CharUnits Align,const Twine & Name,Address * Alloca)141 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
142 const Twine &Name, Address *Alloca) {
143 Address Result = CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name,
144 /*ArraySize=*/nullptr, Alloca);
145
146 if (Ty->isConstantMatrixType()) {
147 auto *ArrayTy = cast<llvm::ArrayType>(Result.getElementType());
148 auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
149 ArrayTy->getNumElements());
150
151 Result = Address(Result.getPointer(), VectorTy, Result.getAlignment(),
152 KnownNonNull);
153 }
154 return Result;
155 }
156
CreateMemTempWithoutCast(QualType Ty,CharUnits Align,const Twine & Name)157 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty, CharUnits Align,
158 const Twine &Name) {
159 return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
160 }
161
CreateMemTempWithoutCast(QualType Ty,const Twine & Name)162 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty,
163 const Twine &Name) {
164 return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
165 Name);
166 }
167
168 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
169 /// expression and compare the result against zero, returning an Int1Ty value.
EvaluateExprAsBool(const Expr * E)170 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) {
171 PGO.setCurrentStmt(E);
172 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
173 llvm::Value *MemPtr = EmitScalarExpr(E);
174 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
175 }
176
177 QualType BoolTy = getContext().BoolTy;
178 SourceLocation Loc = E->getExprLoc();
179 CGFPOptionsRAII FPOptsRAII(*this, E);
180 if (!E->getType()->isAnyComplexType())
181 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
182
183 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
184 Loc);
185 }
186
187 /// EmitIgnoredExpr - Emit code to compute the specified expression,
188 /// ignoring the result.
EmitIgnoredExpr(const Expr * E)189 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) {
190 if (E->isPRValue())
191 return (void)EmitAnyExpr(E, AggValueSlot::ignored(), true);
192
193 // if this is a bitfield-resulting conditional operator, we can special case
194 // emit this. The normal 'EmitLValue' version of this is particularly
195 // difficult to codegen for, since creating a single "LValue" for two
196 // different sized arguments here is not particularly doable.
197 if (const auto *CondOp = dyn_cast<AbstractConditionalOperator>(
198 E->IgnoreParenNoopCasts(getContext()))) {
199 if (CondOp->getObjectKind() == OK_BitField)
200 return EmitIgnoredConditionalOperator(CondOp);
201 }
202
203 // Just emit it as an l-value and drop the result.
204 EmitLValue(E);
205 }
206
207 /// EmitAnyExpr - Emit code to compute the specified expression which
208 /// can have any type. The result is returned as an RValue struct.
209 /// If this is an aggregate expression, AggSlot indicates where the
210 /// result should be returned.
EmitAnyExpr(const Expr * E,AggValueSlot aggSlot,bool ignoreResult)211 RValue CodeGenFunction::EmitAnyExpr(const Expr *E,
212 AggValueSlot aggSlot,
213 bool ignoreResult) {
214 switch (getEvaluationKind(E->getType())) {
215 case TEK_Scalar:
216 return RValue::get(EmitScalarExpr(E, ignoreResult));
217 case TEK_Complex:
218 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
219 case TEK_Aggregate:
220 if (!ignoreResult && aggSlot.isIgnored())
221 aggSlot = CreateAggTemp(E->getType(), "agg-temp");
222 EmitAggExpr(E, aggSlot);
223 return aggSlot.asRValue();
224 }
225 llvm_unreachable("bad evaluation kind");
226 }
227
228 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
229 /// always be accessible even if no aggregate location is provided.
EmitAnyExprToTemp(const Expr * E)230 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) {
231 AggValueSlot AggSlot = AggValueSlot::ignored();
232
233 if (hasAggregateEvaluationKind(E->getType()))
234 AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
235 return EmitAnyExpr(E, AggSlot);
236 }
237
238 /// EmitAnyExprToMem - Evaluate an expression into a given memory
239 /// location.
EmitAnyExprToMem(const Expr * E,Address Location,Qualifiers Quals,bool IsInit)240 void CodeGenFunction::EmitAnyExprToMem(const Expr *E,
241 Address Location,
242 Qualifiers Quals,
243 bool IsInit) {
244 // FIXME: This function should take an LValue as an argument.
245 switch (getEvaluationKind(E->getType())) {
246 case TEK_Complex:
247 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()),
248 /*isInit*/ false);
249 return;
250
251 case TEK_Aggregate: {
252 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
253 AggValueSlot::IsDestructed_t(IsInit),
254 AggValueSlot::DoesNotNeedGCBarriers,
255 AggValueSlot::IsAliased_t(!IsInit),
256 AggValueSlot::MayOverlap));
257 return;
258 }
259
260 case TEK_Scalar: {
261 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
262 LValue LV = MakeAddrLValue(Location, E->getType());
263 EmitStoreThroughLValue(RV, LV);
264 return;
265 }
266 }
267 llvm_unreachable("bad evaluation kind");
268 }
269
270 static void
pushTemporaryCleanup(CodeGenFunction & CGF,const MaterializeTemporaryExpr * M,const Expr * E,Address ReferenceTemporary)271 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M,
272 const Expr *E, Address ReferenceTemporary) {
273 // Objective-C++ ARC:
274 // If we are binding a reference to a temporary that has ownership, we
275 // need to perform retain/release operations on the temporary.
276 //
277 // FIXME: This should be looking at E, not M.
278 if (auto Lifetime = M->getType().getObjCLifetime()) {
279 switch (Lifetime) {
280 case Qualifiers::OCL_None:
281 case Qualifiers::OCL_ExplicitNone:
282 // Carry on to normal cleanup handling.
283 break;
284
285 case Qualifiers::OCL_Autoreleasing:
286 // Nothing to do; cleaned up by an autorelease pool.
287 return;
288
289 case Qualifiers::OCL_Strong:
290 case Qualifiers::OCL_Weak:
291 switch (StorageDuration Duration = M->getStorageDuration()) {
292 case SD_Static:
293 // Note: we intentionally do not register a cleanup to release
294 // the object on program termination.
295 return;
296
297 case SD_Thread:
298 // FIXME: We should probably register a cleanup in this case.
299 return;
300
301 case SD_Automatic:
302 case SD_FullExpression:
303 CodeGenFunction::Destroyer *Destroy;
304 CleanupKind CleanupKind;
305 if (Lifetime == Qualifiers::OCL_Strong) {
306 const ValueDecl *VD = M->getExtendingDecl();
307 bool Precise =
308 VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
309 CleanupKind = CGF.getARCCleanupKind();
310 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise
311 : &CodeGenFunction::destroyARCStrongImprecise;
312 } else {
313 // __weak objects always get EH cleanups; otherwise, exceptions
314 // could cause really nasty crashes instead of mere leaks.
315 CleanupKind = NormalAndEHCleanup;
316 Destroy = &CodeGenFunction::destroyARCWeak;
317 }
318 if (Duration == SD_FullExpression)
319 CGF.pushDestroy(CleanupKind, ReferenceTemporary,
320 M->getType(), *Destroy,
321 CleanupKind & EHCleanup);
322 else
323 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
324 M->getType(),
325 *Destroy, CleanupKind & EHCleanup);
326 return;
327
328 case SD_Dynamic:
329 llvm_unreachable("temporary cannot have dynamic storage duration");
330 }
331 llvm_unreachable("unknown storage duration");
332 }
333 }
334
335 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
336 if (const RecordType *RT =
337 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) {
338 // Get the destructor for the reference temporary.
339 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
340 if (!ClassDecl->hasTrivialDestructor())
341 ReferenceTemporaryDtor = ClassDecl->getDestructor();
342 }
343
344 if (!ReferenceTemporaryDtor)
345 return;
346
347 // Call the destructor for the temporary.
348 switch (M->getStorageDuration()) {
349 case SD_Static:
350 case SD_Thread: {
351 llvm::FunctionCallee CleanupFn;
352 llvm::Constant *CleanupArg;
353 if (E->getType()->isArrayType()) {
354 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
355 ReferenceTemporary, E->getType(),
356 CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions,
357 dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
358 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
359 } else {
360 CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
361 GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
362 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
363 }
364 CGF.CGM.getCXXABI().registerGlobalDtor(
365 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
366 break;
367 }
368
369 case SD_FullExpression:
370 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
371 CodeGenFunction::destroyCXXObject,
372 CGF.getLangOpts().Exceptions);
373 break;
374
375 case SD_Automatic:
376 CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup,
377 ReferenceTemporary, E->getType(),
378 CodeGenFunction::destroyCXXObject,
379 CGF.getLangOpts().Exceptions);
380 break;
381
382 case SD_Dynamic:
383 llvm_unreachable("temporary cannot have dynamic storage duration");
384 }
385 }
386
createReferenceTemporary(CodeGenFunction & CGF,const MaterializeTemporaryExpr * M,const Expr * Inner,Address * Alloca=nullptr)387 static Address createReferenceTemporary(CodeGenFunction &CGF,
388 const MaterializeTemporaryExpr *M,
389 const Expr *Inner,
390 Address *Alloca = nullptr) {
391 auto &TCG = CGF.getTargetHooks();
392 switch (M->getStorageDuration()) {
393 case SD_FullExpression:
394 case SD_Automatic: {
395 // If we have a constant temporary array or record try to promote it into a
396 // constant global under the same rules a normal constant would've been
397 // promoted. This is easier on the optimizer and generally emits fewer
398 // instructions.
399 QualType Ty = Inner->getType();
400 if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
401 (Ty->isArrayType() || Ty->isRecordType()) &&
402 Ty.isConstantStorage(CGF.getContext(), true, false))
403 if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
404 auto AS = CGF.CGM.GetGlobalConstantAddressSpace();
405 auto *GV = new llvm::GlobalVariable(
406 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
407 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
408 llvm::GlobalValue::NotThreadLocal,
409 CGF.getContext().getTargetAddressSpace(AS));
410 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
411 GV->setAlignment(alignment.getAsAlign());
412 llvm::Constant *C = GV;
413 if (AS != LangAS::Default)
414 C = TCG.performAddrSpaceCast(
415 CGF.CGM, GV, AS, LangAS::Default,
416 GV->getValueType()->getPointerTo(
417 CGF.getContext().getTargetAddressSpace(LangAS::Default)));
418 // FIXME: Should we put the new global into a COMDAT?
419 return Address(C, GV->getValueType(), alignment);
420 }
421 return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
422 }
423 case SD_Thread:
424 case SD_Static:
425 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
426
427 case SD_Dynamic:
428 llvm_unreachable("temporary can't have dynamic storage duration");
429 }
430 llvm_unreachable("unknown storage duration");
431 }
432
433 /// Helper method to check if the underlying ABI is AAPCS
isAAPCS(const TargetInfo & TargetInfo)434 static bool isAAPCS(const TargetInfo &TargetInfo) {
435 return TargetInfo.getABI().starts_with("aapcs");
436 }
437
438 LValue CodeGenFunction::
EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr * M)439 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) {
440 const Expr *E = M->getSubExpr();
441
442 assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
443 !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
444 "Reference should never be pseudo-strong!");
445
446 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
447 // as that will cause the lifetime adjustment to be lost for ARC
448 auto ownership = M->getType().getObjCLifetime();
449 if (ownership != Qualifiers::OCL_None &&
450 ownership != Qualifiers::OCL_ExplicitNone) {
451 Address Object = createReferenceTemporary(*this, M, E);
452 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
453 llvm::Type *Ty = ConvertTypeForMem(E->getType());
454 Object = Object.withElementType(Ty);
455
456 // createReferenceTemporary will promote the temporary to a global with a
457 // constant initializer if it can. It can only do this to a value of
458 // ARC-manageable type if the value is global and therefore "immune" to
459 // ref-counting operations. Therefore we have no need to emit either a
460 // dynamic initialization or a cleanup and we can just return the address
461 // of the temporary.
462 if (Var->hasInitializer())
463 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
464
465 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
466 }
467 LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
468 AlignmentSource::Decl);
469
470 switch (getEvaluationKind(E->getType())) {
471 default: llvm_unreachable("expected scalar or aggregate expression");
472 case TEK_Scalar:
473 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
474 break;
475 case TEK_Aggregate: {
476 EmitAggExpr(E, AggValueSlot::forAddr(Object,
477 E->getType().getQualifiers(),
478 AggValueSlot::IsDestructed,
479 AggValueSlot::DoesNotNeedGCBarriers,
480 AggValueSlot::IsNotAliased,
481 AggValueSlot::DoesNotOverlap));
482 break;
483 }
484 }
485
486 pushTemporaryCleanup(*this, M, E, Object);
487 return RefTempDst;
488 }
489
490 SmallVector<const Expr *, 2> CommaLHSs;
491 SmallVector<SubobjectAdjustment, 2> Adjustments;
492 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
493
494 for (const auto &Ignored : CommaLHSs)
495 EmitIgnoredExpr(Ignored);
496
497 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
498 if (opaque->getType()->isRecordType()) {
499 assert(Adjustments.empty());
500 return EmitOpaqueValueLValue(opaque);
501 }
502 }
503
504 // Create and initialize the reference temporary.
505 Address Alloca = Address::invalid();
506 Address Object = createReferenceTemporary(*this, M, E, &Alloca);
507 if (auto *Var = dyn_cast<llvm::GlobalVariable>(
508 Object.getPointer()->stripPointerCasts())) {
509 llvm::Type *TemporaryType = ConvertTypeForMem(E->getType());
510 Object = Object.withElementType(TemporaryType);
511 // If the temporary is a global and has a constant initializer or is a
512 // constant temporary that we promoted to a global, we may have already
513 // initialized it.
514 if (!Var->hasInitializer()) {
515 Var->setInitializer(CGM.EmitNullConstant(E->getType()));
516 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
517 }
518 } else {
519 switch (M->getStorageDuration()) {
520 case SD_Automatic:
521 if (auto *Size = EmitLifetimeStart(
522 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
523 Alloca.getPointer())) {
524 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
525 Alloca, Size);
526 }
527 break;
528
529 case SD_FullExpression: {
530 if (!ShouldEmitLifetimeMarkers)
531 break;
532
533 // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
534 // marker. Instead, start the lifetime of a conditional temporary earlier
535 // so that it's unconditional. Don't do this with sanitizers which need
536 // more precise lifetime marks. However when inside an "await.suspend"
537 // block, we should always avoid conditional cleanup because it creates
538 // boolean marker that lives across await_suspend, which can destroy coro
539 // frame.
540 ConditionalEvaluation *OldConditional = nullptr;
541 CGBuilderTy::InsertPoint OldIP;
542 if (isInConditionalBranch() && !E->getType().isDestructedType() &&
543 ((!SanOpts.has(SanitizerKind::HWAddress) &&
544 !SanOpts.has(SanitizerKind::Memory) &&
545 !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) ||
546 inSuspendBlock())) {
547 OldConditional = OutermostConditional;
548 OutermostConditional = nullptr;
549
550 OldIP = Builder.saveIP();
551 llvm::BasicBlock *Block = OldConditional->getStartingBlock();
552 Builder.restoreIP(CGBuilderTy::InsertPoint(
553 Block, llvm::BasicBlock::iterator(Block->back())));
554 }
555
556 if (auto *Size = EmitLifetimeStart(
557 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
558 Alloca.getPointer())) {
559 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
560 Size);
561 }
562
563 if (OldConditional) {
564 OutermostConditional = OldConditional;
565 Builder.restoreIP(OldIP);
566 }
567 break;
568 }
569
570 default:
571 break;
572 }
573 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
574 }
575 pushTemporaryCleanup(*this, M, E, Object);
576
577 // Perform derived-to-base casts and/or field accesses, to get from the
578 // temporary object we created (and, potentially, for which we extended
579 // the lifetime) to the subobject we're binding the reference to.
580 for (SubobjectAdjustment &Adjustment : llvm::reverse(Adjustments)) {
581 switch (Adjustment.Kind) {
582 case SubobjectAdjustment::DerivedToBaseAdjustment:
583 Object =
584 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
585 Adjustment.DerivedToBase.BasePath->path_begin(),
586 Adjustment.DerivedToBase.BasePath->path_end(),
587 /*NullCheckValue=*/ false, E->getExprLoc());
588 break;
589
590 case SubobjectAdjustment::FieldAdjustment: {
591 LValue LV = MakeAddrLValue(Object, E->getType(), AlignmentSource::Decl);
592 LV = EmitLValueForField(LV, Adjustment.Field);
593 assert(LV.isSimple() &&
594 "materialized temporary field is not a simple lvalue");
595 Object = LV.getAddress(*this);
596 break;
597 }
598
599 case SubobjectAdjustment::MemberPointerAdjustment: {
600 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
601 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
602 Adjustment.Ptr.MPT);
603 break;
604 }
605 }
606 }
607
608 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
609 }
610
611 RValue
EmitReferenceBindingToExpr(const Expr * E)612 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) {
613 // Emit the expression as an lvalue.
614 LValue LV = EmitLValue(E);
615 assert(LV.isSimple());
616 llvm::Value *Value = LV.getPointer(*this);
617
618 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
619 // C++11 [dcl.ref]p5 (as amended by core issue 453):
620 // If a glvalue to which a reference is directly bound designates neither
621 // an existing object or function of an appropriate type nor a region of
622 // storage of suitable size and alignment to contain an object of the
623 // reference's type, the behavior is undefined.
624 QualType Ty = E->getType();
625 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty);
626 }
627
628 return RValue::get(Value);
629 }
630
631
632 /// getAccessedFieldNo - Given an encoded value and a result number, return the
633 /// input field number being accessed.
getAccessedFieldNo(unsigned Idx,const llvm::Constant * Elts)634 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx,
635 const llvm::Constant *Elts) {
636 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
637 ->getZExtValue();
638 }
639
640 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
emitHash16Bytes(CGBuilderTy & Builder,llvm::Value * Low,llvm::Value * High)641 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low,
642 llvm::Value *High) {
643 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
644 llvm::Value *K47 = Builder.getInt64(47);
645 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
646 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
647 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
648 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
649 return Builder.CreateMul(B1, KMul);
650 }
651
isNullPointerAllowed(TypeCheckKind TCK)652 bool CodeGenFunction::isNullPointerAllowed(TypeCheckKind TCK) {
653 return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
654 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation;
655 }
656
isVptrCheckRequired(TypeCheckKind TCK,QualType Ty)657 bool CodeGenFunction::isVptrCheckRequired(TypeCheckKind TCK, QualType Ty) {
658 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
659 return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
660 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
661 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
662 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation);
663 }
664
sanitizePerformTypeCheck() const665 bool CodeGenFunction::sanitizePerformTypeCheck() const {
666 return SanOpts.has(SanitizerKind::Null) ||
667 SanOpts.has(SanitizerKind::Alignment) ||
668 SanOpts.has(SanitizerKind::ObjectSize) ||
669 SanOpts.has(SanitizerKind::Vptr);
670 }
671
EmitTypeCheck(TypeCheckKind TCK,SourceLocation Loc,llvm::Value * Ptr,QualType Ty,CharUnits Alignment,SanitizerSet SkippedChecks,llvm::Value * ArraySize)672 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc,
673 llvm::Value *Ptr, QualType Ty,
674 CharUnits Alignment,
675 SanitizerSet SkippedChecks,
676 llvm::Value *ArraySize) {
677 if (!sanitizePerformTypeCheck())
678 return;
679
680 // Don't check pointers outside the default address space. The null check
681 // isn't correct, the object-size check isn't supported by LLVM, and we can't
682 // communicate the addresses to the runtime handler for the vptr check.
683 if (Ptr->getType()->getPointerAddressSpace())
684 return;
685
686 // Don't check pointers to volatile data. The behavior here is implementation-
687 // defined.
688 if (Ty.isVolatileQualified())
689 return;
690
691 SanitizerScope SanScope(this);
692
693 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks;
694 llvm::BasicBlock *Done = nullptr;
695
696 // Quickly determine whether we have a pointer to an alloca. It's possible
697 // to skip null checks, and some alignment checks, for these pointers. This
698 // can reduce compile-time significantly.
699 auto PtrToAlloca = dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCasts());
700
701 llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
702 llvm::Value *IsNonNull = nullptr;
703 bool IsGuaranteedNonNull =
704 SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
705 bool AllowNullPointers = isNullPointerAllowed(TCK);
706 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
707 !IsGuaranteedNonNull) {
708 // The glvalue must not be an empty glvalue.
709 IsNonNull = Builder.CreateIsNotNull(Ptr);
710
711 // The IR builder can constant-fold the null check if the pointer points to
712 // a constant.
713 IsGuaranteedNonNull = IsNonNull == True;
714
715 // Skip the null check if the pointer is known to be non-null.
716 if (!IsGuaranteedNonNull) {
717 if (AllowNullPointers) {
718 // When performing pointer casts, it's OK if the value is null.
719 // Skip the remaining checks in that case.
720 Done = createBasicBlock("null");
721 llvm::BasicBlock *Rest = createBasicBlock("not.null");
722 Builder.CreateCondBr(IsNonNull, Rest, Done);
723 EmitBlock(Rest);
724 } else {
725 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
726 }
727 }
728 }
729
730 if (SanOpts.has(SanitizerKind::ObjectSize) &&
731 !SkippedChecks.has(SanitizerKind::ObjectSize) &&
732 !Ty->isIncompleteType()) {
733 uint64_t TySize = CGM.getMinimumObjectSize(Ty).getQuantity();
734 llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
735 if (ArraySize)
736 Size = Builder.CreateMul(Size, ArraySize);
737
738 // Degenerate case: new X[0] does not need an objectsize check.
739 llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
740 if (!ConstantSize || !ConstantSize->isNullValue()) {
741 // The glvalue must refer to a large enough storage region.
742 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
743 // to check this.
744 // FIXME: Get object address space
745 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
746 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
747 llvm::Value *Min = Builder.getFalse();
748 llvm::Value *NullIsUnknown = Builder.getFalse();
749 llvm::Value *Dynamic = Builder.getFalse();
750 llvm::Value *LargeEnough = Builder.CreateICmpUGE(
751 Builder.CreateCall(F, {Ptr, Min, NullIsUnknown, Dynamic}), Size);
752 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
753 }
754 }
755
756 llvm::MaybeAlign AlignVal;
757 llvm::Value *PtrAsInt = nullptr;
758
759 if (SanOpts.has(SanitizerKind::Alignment) &&
760 !SkippedChecks.has(SanitizerKind::Alignment)) {
761 AlignVal = Alignment.getAsMaybeAlign();
762 if (!Ty->isIncompleteType() && !AlignVal)
763 AlignVal = CGM.getNaturalTypeAlignment(Ty, nullptr, nullptr,
764 /*ForPointeeType=*/true)
765 .getAsMaybeAlign();
766
767 // The glvalue must be suitably aligned.
768 if (AlignVal && *AlignVal > llvm::Align(1) &&
769 (!PtrToAlloca || PtrToAlloca->getAlign() < *AlignVal)) {
770 PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
771 llvm::Value *Align = Builder.CreateAnd(
772 PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal->value() - 1));
773 llvm::Value *Aligned =
774 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
775 if (Aligned != True)
776 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
777 }
778 }
779
780 if (Checks.size() > 0) {
781 llvm::Constant *StaticData[] = {
782 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty),
783 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2(*AlignVal) : 1),
784 llvm::ConstantInt::get(Int8Ty, TCK)};
785 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
786 PtrAsInt ? PtrAsInt : Ptr);
787 }
788
789 // If possible, check that the vptr indicates that there is a subobject of
790 // type Ty at offset zero within this object.
791 //
792 // C++11 [basic.life]p5,6:
793 // [For storage which does not refer to an object within its lifetime]
794 // The program has undefined behavior if:
795 // -- the [pointer or glvalue] is used to access a non-static data member
796 // or call a non-static member function
797 if (SanOpts.has(SanitizerKind::Vptr) &&
798 !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
799 // Ensure that the pointer is non-null before loading it. If there is no
800 // compile-time guarantee, reuse the run-time null check or emit a new one.
801 if (!IsGuaranteedNonNull) {
802 if (!IsNonNull)
803 IsNonNull = Builder.CreateIsNotNull(Ptr);
804 if (!Done)
805 Done = createBasicBlock("vptr.null");
806 llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
807 Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
808 EmitBlock(VptrNotNull);
809 }
810
811 // Compute a hash of the mangled name of the type.
812 //
813 // FIXME: This is not guaranteed to be deterministic! Move to a
814 // fingerprinting mechanism once LLVM provides one. For the time
815 // being the implementation happens to be deterministic.
816 SmallString<64> MangledName;
817 llvm::raw_svector_ostream Out(MangledName);
818 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(),
819 Out);
820
821 // Contained in NoSanitizeList based on the mangled type.
822 if (!CGM.getContext().getNoSanitizeList().containsType(SanitizerKind::Vptr,
823 Out.str())) {
824 llvm::hash_code TypeHash = hash_value(Out.str());
825
826 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
827 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
828 Address VPtrAddr(Ptr, IntPtrTy, getPointerAlign());
829 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
830 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
831
832 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
833 Hash = Builder.CreateTrunc(Hash, IntPtrTy);
834
835 // Look the hash up in our cache.
836 const int CacheSize = 128;
837 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
838 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable,
839 "__ubsan_vptr_type_cache");
840 llvm::Value *Slot = Builder.CreateAnd(Hash,
841 llvm::ConstantInt::get(IntPtrTy,
842 CacheSize-1));
843 llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
844 llvm::Value *CacheVal = Builder.CreateAlignedLoad(
845 IntPtrTy, Builder.CreateInBoundsGEP(HashTable, Cache, Indices),
846 getPointerAlign());
847
848 // If the hash isn't in the cache, call a runtime handler to perform the
849 // hard work of checking whether the vptr is for an object of the right
850 // type. This will either fill in the cache and return, or produce a
851 // diagnostic.
852 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
853 llvm::Constant *StaticData[] = {
854 EmitCheckSourceLocation(Loc),
855 EmitCheckTypeDescriptor(Ty),
856 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()),
857 llvm::ConstantInt::get(Int8Ty, TCK)
858 };
859 llvm::Value *DynamicData[] = { Ptr, Hash };
860 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
861 SanitizerHandler::DynamicTypeCacheMiss, StaticData,
862 DynamicData);
863 }
864 }
865
866 if (Done) {
867 Builder.CreateBr(Done);
868 EmitBlock(Done);
869 }
870 }
871
LoadPassedObjectSize(const Expr * E,QualType EltTy)872 llvm::Value *CodeGenFunction::LoadPassedObjectSize(const Expr *E,
873 QualType EltTy) {
874 ASTContext &C = getContext();
875 uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
876 if (!EltSize)
877 return nullptr;
878
879 auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
880 if (!ArrayDeclRef)
881 return nullptr;
882
883 auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
884 if (!ParamDecl)
885 return nullptr;
886
887 auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
888 if (!POSAttr)
889 return nullptr;
890
891 // Don't load the size if it's a lower bound.
892 int POSType = POSAttr->getType();
893 if (POSType != 0 && POSType != 1)
894 return nullptr;
895
896 // Find the implicit size parameter.
897 auto PassedSizeIt = SizeArguments.find(ParamDecl);
898 if (PassedSizeIt == SizeArguments.end())
899 return nullptr;
900
901 const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
902 assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
903 Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
904 llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
905 C.getSizeType(), E->getExprLoc());
906 llvm::Value *SizeOfElement =
907 llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
908 return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
909 }
910
911 /// If Base is known to point to the start of an array, return the length of
912 /// that array. Return 0 if the length cannot be determined.
getArrayIndexingBound(CodeGenFunction & CGF,const Expr * Base,QualType & IndexedType,LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel)913 static llvm::Value *getArrayIndexingBound(CodeGenFunction &CGF,
914 const Expr *Base,
915 QualType &IndexedType,
916 LangOptions::StrictFlexArraysLevelKind
917 StrictFlexArraysLevel) {
918 // For the vector indexing extension, the bound is the number of elements.
919 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
920 IndexedType = Base->getType();
921 return CGF.Builder.getInt32(VT->getNumElements());
922 }
923
924 Base = Base->IgnoreParens();
925
926 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
927 if (CE->getCastKind() == CK_ArrayToPointerDecay &&
928 !CE->getSubExpr()->isFlexibleArrayMemberLike(CGF.getContext(),
929 StrictFlexArraysLevel)) {
930 CodeGenFunction::SanitizerScope SanScope(&CGF);
931
932 IndexedType = CE->getSubExpr()->getType();
933 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
934 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
935 return CGF.Builder.getInt(CAT->getSize());
936
937 if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
938 return CGF.getVLASize(VAT).NumElts;
939 // Ignore pass_object_size here. It's not applicable on decayed pointers.
940 }
941 }
942
943 CodeGenFunction::SanitizerScope SanScope(&CGF);
944
945 QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
946 if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
947 IndexedType = Base->getType();
948 return POS;
949 }
950
951 return nullptr;
952 }
953
954 namespace {
955
956 /// \p StructAccessBase returns the base \p Expr of a field access. It returns
957 /// either a \p DeclRefExpr, representing the base pointer to the struct, i.e.:
958 ///
959 /// p in p-> a.b.c
960 ///
961 /// or a \p MemberExpr, if the \p MemberExpr has the \p RecordDecl we're
962 /// looking for:
963 ///
964 /// struct s {
965 /// struct s *ptr;
966 /// int count;
967 /// char array[] __attribute__((counted_by(count)));
968 /// };
969 ///
970 /// If we have an expression like \p p->ptr->array[index], we want the
971 /// \p MemberExpr for \p p->ptr instead of \p p.
972 class StructAccessBase
973 : public ConstStmtVisitor<StructAccessBase, const Expr *> {
974 const RecordDecl *ExpectedRD;
975
IsExpectedRecordDecl(const Expr * E) const976 bool IsExpectedRecordDecl(const Expr *E) const {
977 QualType Ty = E->getType();
978 if (Ty->isPointerType())
979 Ty = Ty->getPointeeType();
980 return ExpectedRD == Ty->getAsRecordDecl();
981 }
982
983 public:
StructAccessBase(const RecordDecl * ExpectedRD)984 StructAccessBase(const RecordDecl *ExpectedRD) : ExpectedRD(ExpectedRD) {}
985
986 //===--------------------------------------------------------------------===//
987 // Visitor Methods
988 //===--------------------------------------------------------------------===//
989
990 // NOTE: If we build C++ support for counted_by, then we'll have to handle
991 // horrors like this:
992 //
993 // struct S {
994 // int x, y;
995 // int blah[] __attribute__((counted_by(x)));
996 // } s;
997 //
998 // int foo(int index, int val) {
999 // int (S::*IHatePMDs)[] = &S::blah;
1000 // (s.*IHatePMDs)[index] = val;
1001 // }
1002
Visit(const Expr * E)1003 const Expr *Visit(const Expr *E) {
1004 return ConstStmtVisitor<StructAccessBase, const Expr *>::Visit(E);
1005 }
1006
VisitStmt(const Stmt * S)1007 const Expr *VisitStmt(const Stmt *S) { return nullptr; }
1008
1009 // These are the types we expect to return (in order of most to least
1010 // likely):
1011 //
1012 // 1. DeclRefExpr - This is the expression for the base of the structure.
1013 // It's exactly what we want to build an access to the \p counted_by
1014 // field.
1015 // 2. MemberExpr - This is the expression that has the same \p RecordDecl
1016 // as the flexble array member's lexical enclosing \p RecordDecl. This
1017 // allows us to catch things like: "p->p->array"
1018 // 3. CompoundLiteralExpr - This is for people who create something
1019 // heretical like (struct foo has a flexible array member):
1020 //
1021 // (struct foo){ 1, 2 }.blah[idx];
VisitDeclRefExpr(const DeclRefExpr * E)1022 const Expr *VisitDeclRefExpr(const DeclRefExpr *E) {
1023 return IsExpectedRecordDecl(E) ? E : nullptr;
1024 }
VisitMemberExpr(const MemberExpr * E)1025 const Expr *VisitMemberExpr(const MemberExpr *E) {
1026 if (IsExpectedRecordDecl(E) && E->isArrow())
1027 return E;
1028 const Expr *Res = Visit(E->getBase());
1029 return !Res && IsExpectedRecordDecl(E) ? E : Res;
1030 }
VisitCompoundLiteralExpr(const CompoundLiteralExpr * E)1031 const Expr *VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1032 return IsExpectedRecordDecl(E) ? E : nullptr;
1033 }
VisitCallExpr(const CallExpr * E)1034 const Expr *VisitCallExpr(const CallExpr *E) {
1035 return IsExpectedRecordDecl(E) ? E : nullptr;
1036 }
1037
VisitArraySubscriptExpr(const ArraySubscriptExpr * E)1038 const Expr *VisitArraySubscriptExpr(const ArraySubscriptExpr *E) {
1039 if (IsExpectedRecordDecl(E))
1040 return E;
1041 return Visit(E->getBase());
1042 }
VisitCastExpr(const CastExpr * E)1043 const Expr *VisitCastExpr(const CastExpr *E) {
1044 return Visit(E->getSubExpr());
1045 }
VisitParenExpr(const ParenExpr * E)1046 const Expr *VisitParenExpr(const ParenExpr *E) {
1047 return Visit(E->getSubExpr());
1048 }
VisitUnaryAddrOf(const UnaryOperator * E)1049 const Expr *VisitUnaryAddrOf(const UnaryOperator *E) {
1050 return Visit(E->getSubExpr());
1051 }
VisitUnaryDeref(const UnaryOperator * E)1052 const Expr *VisitUnaryDeref(const UnaryOperator *E) {
1053 return Visit(E->getSubExpr());
1054 }
1055 };
1056
1057 } // end anonymous namespace
1058
1059 using RecIndicesTy =
1060 SmallVector<std::pair<const RecordDecl *, llvm::Value *>, 8>;
1061
getGEPIndicesToField(CodeGenFunction & CGF,const RecordDecl * RD,const FieldDecl * FD,RecIndicesTy & Indices)1062 static bool getGEPIndicesToField(CodeGenFunction &CGF, const RecordDecl *RD,
1063 const FieldDecl *FD, RecIndicesTy &Indices) {
1064 const CGRecordLayout &Layout = CGF.CGM.getTypes().getCGRecordLayout(RD);
1065 int64_t FieldNo = -1;
1066 for (const Decl *D : RD->decls()) {
1067 if (const auto *Field = dyn_cast<FieldDecl>(D)) {
1068 FieldNo = Layout.getLLVMFieldNo(Field);
1069 if (FD == Field) {
1070 Indices.emplace_back(std::make_pair(RD, CGF.Builder.getInt32(FieldNo)));
1071 return true;
1072 }
1073 }
1074
1075 if (const auto *Record = dyn_cast<RecordDecl>(D)) {
1076 ++FieldNo;
1077 if (getGEPIndicesToField(CGF, Record, FD, Indices)) {
1078 if (RD->isUnion())
1079 FieldNo = 0;
1080 Indices.emplace_back(std::make_pair(RD, CGF.Builder.getInt32(FieldNo)));
1081 return true;
1082 }
1083 }
1084 }
1085
1086 return false;
1087 }
1088
1089 /// This method is typically called in contexts where we can't generate
1090 /// side-effects, like in __builtin_dynamic_object_size. When finding
1091 /// expressions, only choose those that have either already been emitted or can
1092 /// be loaded without side-effects.
1093 ///
1094 /// - \p FAMDecl: the \p Decl for the flexible array member. It may not be
1095 /// within the top-level struct.
1096 /// - \p CountDecl: must be within the same non-anonymous struct as \p FAMDecl.
EmitCountedByFieldExpr(const Expr * Base,const FieldDecl * FAMDecl,const FieldDecl * CountDecl)1097 llvm::Value *CodeGenFunction::EmitCountedByFieldExpr(
1098 const Expr *Base, const FieldDecl *FAMDecl, const FieldDecl *CountDecl) {
1099 const RecordDecl *RD = CountDecl->getParent()->getOuterLexicalRecordContext();
1100
1101 // Find the base struct expr (i.e. p in p->a.b.c.d).
1102 const Expr *StructBase = StructAccessBase(RD).Visit(Base);
1103 if (!StructBase || StructBase->HasSideEffects(getContext()))
1104 return nullptr;
1105
1106 llvm::Value *Res = nullptr;
1107 if (const auto *DRE = dyn_cast<DeclRefExpr>(StructBase)) {
1108 Res = EmitDeclRefLValue(DRE).getPointer(*this);
1109 Res = Builder.CreateAlignedLoad(ConvertType(DRE->getType()), Res,
1110 getPointerAlign(), "dre.load");
1111 } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(StructBase)) {
1112 LValue LV = EmitMemberExpr(ME);
1113 Address Addr = LV.getAddress(*this);
1114 Res = Addr.getPointer();
1115 } else if (StructBase->getType()->isPointerType()) {
1116 LValueBaseInfo BaseInfo;
1117 TBAAAccessInfo TBAAInfo;
1118 Address Addr = EmitPointerWithAlignment(StructBase, &BaseInfo, &TBAAInfo);
1119 Res = Addr.getPointer();
1120 } else {
1121 return nullptr;
1122 }
1123
1124 llvm::Value *Zero = Builder.getInt32(0);
1125 RecIndicesTy Indices;
1126
1127 getGEPIndicesToField(*this, RD, CountDecl, Indices);
1128
1129 for (auto I = Indices.rbegin(), E = Indices.rend(); I != E; ++I)
1130 Res = Builder.CreateInBoundsGEP(
1131 ConvertType(QualType(I->first->getTypeForDecl(), 0)), Res,
1132 {Zero, I->second}, "..counted_by.gep");
1133
1134 return Builder.CreateAlignedLoad(ConvertType(CountDecl->getType()), Res,
1135 getIntAlign(), "..counted_by.load");
1136 }
1137
FindCountedByField(const FieldDecl * FD)1138 const FieldDecl *CodeGenFunction::FindCountedByField(const FieldDecl *FD) {
1139 if (!FD || !FD->hasAttr<CountedByAttr>())
1140 return nullptr;
1141
1142 const auto *CBA = FD->getAttr<CountedByAttr>();
1143 if (!CBA)
1144 return nullptr;
1145
1146 auto GetNonAnonStructOrUnion =
1147 [](const RecordDecl *RD) -> const RecordDecl * {
1148 while (RD && RD->isAnonymousStructOrUnion()) {
1149 const auto *R = dyn_cast<RecordDecl>(RD->getDeclContext());
1150 if (!R)
1151 return nullptr;
1152 RD = R;
1153 }
1154 return RD;
1155 };
1156 const RecordDecl *EnclosingRD = GetNonAnonStructOrUnion(FD->getParent());
1157 if (!EnclosingRD)
1158 return nullptr;
1159
1160 DeclarationName DName(CBA->getCountedByField());
1161 DeclContext::lookup_result Lookup = EnclosingRD->lookup(DName);
1162
1163 if (Lookup.empty())
1164 return nullptr;
1165
1166 const NamedDecl *ND = Lookup.front();
1167 if (const auto *IFD = dyn_cast<IndirectFieldDecl>(ND))
1168 ND = IFD->getAnonField();
1169
1170 return dyn_cast<FieldDecl>(ND);
1171 }
1172
EmitBoundsCheck(const Expr * E,const Expr * Base,llvm::Value * Index,QualType IndexType,bool Accessed)1173 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base,
1174 llvm::Value *Index, QualType IndexType,
1175 bool Accessed) {
1176 assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
1177 "should not be called unless adding bounds checks");
1178 const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
1179 getLangOpts().getStrictFlexArraysLevel();
1180 QualType IndexedType;
1181 llvm::Value *Bound =
1182 getArrayIndexingBound(*this, Base, IndexedType, StrictFlexArraysLevel);
1183
1184 EmitBoundsCheckImpl(E, Bound, Index, IndexType, IndexedType, Accessed);
1185 }
1186
EmitBoundsCheckImpl(const Expr * E,llvm::Value * Bound,llvm::Value * Index,QualType IndexType,QualType IndexedType,bool Accessed)1187 void CodeGenFunction::EmitBoundsCheckImpl(const Expr *E, llvm::Value *Bound,
1188 llvm::Value *Index,
1189 QualType IndexType,
1190 QualType IndexedType, bool Accessed) {
1191 if (!Bound)
1192 return;
1193
1194 SanitizerScope SanScope(this);
1195
1196 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
1197 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
1198 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
1199
1200 llvm::Constant *StaticData[] = {
1201 EmitCheckSourceLocation(E->getExprLoc()),
1202 EmitCheckTypeDescriptor(IndexedType),
1203 EmitCheckTypeDescriptor(IndexType)
1204 };
1205 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
1206 : Builder.CreateICmpULE(IndexVal, BoundVal);
1207 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
1208 SanitizerHandler::OutOfBounds, StaticData, Index);
1209 }
1210
1211 CodeGenFunction::ComplexPairTy CodeGenFunction::
EmitComplexPrePostIncDec(const UnaryOperator * E,LValue LV,bool isInc,bool isPre)1212 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV,
1213 bool isInc, bool isPre) {
1214 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
1215
1216 llvm::Value *NextVal;
1217 if (isa<llvm::IntegerType>(InVal.first->getType())) {
1218 uint64_t AmountVal = isInc ? 1 : -1;
1219 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
1220
1221 // Add the inc/dec to the real part.
1222 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1223 } else {
1224 QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
1225 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1226 if (!isInc)
1227 FVal.changeSign();
1228 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1229
1230 // Add the inc/dec to the real part.
1231 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1232 }
1233
1234 ComplexPairTy IncVal(NextVal, InVal.second);
1235
1236 // Store the updated result through the lvalue.
1237 EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1238 if (getLangOpts().OpenMP)
1239 CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this,
1240 E->getSubExpr());
1241
1242 // If this is a postinc, return the value read from memory, otherwise use the
1243 // updated value.
1244 return isPre ? IncVal : InVal;
1245 }
1246
EmitExplicitCastExprType(const ExplicitCastExpr * E,CodeGenFunction * CGF)1247 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E,
1248 CodeGenFunction *CGF) {
1249 // Bind VLAs in the cast type.
1250 if (CGF && E->getType()->isVariablyModifiedType())
1251 CGF->EmitVariablyModifiedType(E->getType());
1252
1253 if (CGDebugInfo *DI = getModuleDebugInfo())
1254 DI->EmitExplicitCastType(E->getType());
1255 }
1256
1257 //===----------------------------------------------------------------------===//
1258 // LValue Expression Emission
1259 //===----------------------------------------------------------------------===//
1260
EmitPointerWithAlignment(const Expr * E,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo,KnownNonNull_t IsKnownNonNull,CodeGenFunction & CGF)1261 static Address EmitPointerWithAlignment(const Expr *E, LValueBaseInfo *BaseInfo,
1262 TBAAAccessInfo *TBAAInfo,
1263 KnownNonNull_t IsKnownNonNull,
1264 CodeGenFunction &CGF) {
1265 // We allow this with ObjC object pointers because of fragile ABIs.
1266 assert(E->getType()->isPointerType() ||
1267 E->getType()->isObjCObjectPointerType());
1268 E = E->IgnoreParens();
1269
1270 // Casts:
1271 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1272 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1273 CGF.CGM.EmitExplicitCastExprType(ECE, &CGF);
1274
1275 switch (CE->getCastKind()) {
1276 // Non-converting casts (but not C's implicit conversion from void*).
1277 case CK_BitCast:
1278 case CK_NoOp:
1279 case CK_AddressSpaceConversion:
1280 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1281 if (PtrTy->getPointeeType()->isVoidType())
1282 break;
1283
1284 LValueBaseInfo InnerBaseInfo;
1285 TBAAAccessInfo InnerTBAAInfo;
1286 Address Addr = CGF.EmitPointerWithAlignment(
1287 CE->getSubExpr(), &InnerBaseInfo, &InnerTBAAInfo, IsKnownNonNull);
1288 if (BaseInfo) *BaseInfo = InnerBaseInfo;
1289 if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1290
1291 if (isa<ExplicitCastExpr>(CE)) {
1292 LValueBaseInfo TargetTypeBaseInfo;
1293 TBAAAccessInfo TargetTypeTBAAInfo;
1294 CharUnits Align = CGF.CGM.getNaturalPointeeTypeAlignment(
1295 E->getType(), &TargetTypeBaseInfo, &TargetTypeTBAAInfo);
1296 if (TBAAInfo)
1297 *TBAAInfo =
1298 CGF.CGM.mergeTBAAInfoForCast(*TBAAInfo, TargetTypeTBAAInfo);
1299 // If the source l-value is opaque, honor the alignment of the
1300 // casted-to type.
1301 if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1302 if (BaseInfo)
1303 BaseInfo->mergeForCast(TargetTypeBaseInfo);
1304 Addr = Address(Addr.getPointer(), Addr.getElementType(), Align,
1305 IsKnownNonNull);
1306 }
1307 }
1308
1309 if (CGF.SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1310 CE->getCastKind() == CK_BitCast) {
1311 if (auto PT = E->getType()->getAs<PointerType>())
1312 CGF.EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr,
1313 /*MayBeNull=*/true,
1314 CodeGenFunction::CFITCK_UnrelatedCast,
1315 CE->getBeginLoc());
1316 }
1317
1318 llvm::Type *ElemTy =
1319 CGF.ConvertTypeForMem(E->getType()->getPointeeType());
1320 Addr = Addr.withElementType(ElemTy);
1321 if (CE->getCastKind() == CK_AddressSpaceConversion)
1322 Addr = CGF.Builder.CreateAddrSpaceCast(Addr,
1323 CGF.ConvertType(E->getType()));
1324 return Addr;
1325 }
1326 break;
1327
1328 // Array-to-pointer decay.
1329 case CK_ArrayToPointerDecay:
1330 return CGF.EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1331
1332 // Derived-to-base conversions.
1333 case CK_UncheckedDerivedToBase:
1334 case CK_DerivedToBase: {
1335 // TODO: Support accesses to members of base classes in TBAA. For now, we
1336 // conservatively pretend that the complete object is of the base class
1337 // type.
1338 if (TBAAInfo)
1339 *TBAAInfo = CGF.CGM.getTBAAAccessInfo(E->getType());
1340 Address Addr = CGF.EmitPointerWithAlignment(
1341 CE->getSubExpr(), BaseInfo, nullptr,
1342 (KnownNonNull_t)(IsKnownNonNull ||
1343 CE->getCastKind() == CK_UncheckedDerivedToBase));
1344 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1345 return CGF.GetAddressOfBaseClass(
1346 Addr, Derived, CE->path_begin(), CE->path_end(),
1347 CGF.ShouldNullCheckClassCastValue(CE), CE->getExprLoc());
1348 }
1349
1350 // TODO: Is there any reason to treat base-to-derived conversions
1351 // specially?
1352 default:
1353 break;
1354 }
1355 }
1356
1357 // Unary &.
1358 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1359 if (UO->getOpcode() == UO_AddrOf) {
1360 LValue LV = CGF.EmitLValue(UO->getSubExpr(), IsKnownNonNull);
1361 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1362 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1363 return LV.getAddress(CGF);
1364 }
1365 }
1366
1367 // std::addressof and variants.
1368 if (auto *Call = dyn_cast<CallExpr>(E)) {
1369 switch (Call->getBuiltinCallee()) {
1370 default:
1371 break;
1372 case Builtin::BIaddressof:
1373 case Builtin::BI__addressof:
1374 case Builtin::BI__builtin_addressof: {
1375 LValue LV = CGF.EmitLValue(Call->getArg(0), IsKnownNonNull);
1376 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1377 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1378 return LV.getAddress(CGF);
1379 }
1380 }
1381 }
1382
1383 // TODO: conditional operators, comma.
1384
1385 // Otherwise, use the alignment of the type.
1386 CharUnits Align =
1387 CGF.CGM.getNaturalPointeeTypeAlignment(E->getType(), BaseInfo, TBAAInfo);
1388 llvm::Type *ElemTy = CGF.ConvertTypeForMem(E->getType()->getPointeeType());
1389 return Address(CGF.EmitScalarExpr(E), ElemTy, Align, IsKnownNonNull);
1390 }
1391
1392 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1393 /// derive a more accurate bound on the alignment of the pointer.
EmitPointerWithAlignment(const Expr * E,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo,KnownNonNull_t IsKnownNonNull)1394 Address CodeGenFunction::EmitPointerWithAlignment(
1395 const Expr *E, LValueBaseInfo *BaseInfo, TBAAAccessInfo *TBAAInfo,
1396 KnownNonNull_t IsKnownNonNull) {
1397 Address Addr =
1398 ::EmitPointerWithAlignment(E, BaseInfo, TBAAInfo, IsKnownNonNull, *this);
1399 if (IsKnownNonNull && !Addr.isKnownNonNull())
1400 Addr.setKnownNonNull();
1401 return Addr;
1402 }
1403
EmitNonNullRValueCheck(RValue RV,QualType T)1404 llvm::Value *CodeGenFunction::EmitNonNullRValueCheck(RValue RV, QualType T) {
1405 llvm::Value *V = RV.getScalarVal();
1406 if (auto MPT = T->getAs<MemberPointerType>())
1407 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, V, MPT);
1408 return Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType()));
1409 }
1410
GetUndefRValue(QualType Ty)1411 RValue CodeGenFunction::GetUndefRValue(QualType Ty) {
1412 if (Ty->isVoidType())
1413 return RValue::get(nullptr);
1414
1415 switch (getEvaluationKind(Ty)) {
1416 case TEK_Complex: {
1417 llvm::Type *EltTy =
1418 ConvertType(Ty->castAs<ComplexType>()->getElementType());
1419 llvm::Value *U = llvm::UndefValue::get(EltTy);
1420 return RValue::getComplex(std::make_pair(U, U));
1421 }
1422
1423 // If this is a use of an undefined aggregate type, the aggregate must have an
1424 // identifiable address. Just because the contents of the value are undefined
1425 // doesn't mean that the address can't be taken and compared.
1426 case TEK_Aggregate: {
1427 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1428 return RValue::getAggregate(DestPtr);
1429 }
1430
1431 case TEK_Scalar:
1432 return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1433 }
1434 llvm_unreachable("bad evaluation kind");
1435 }
1436
EmitUnsupportedRValue(const Expr * E,const char * Name)1437 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E,
1438 const char *Name) {
1439 ErrorUnsupported(E, Name);
1440 return GetUndefRValue(E->getType());
1441 }
1442
EmitUnsupportedLValue(const Expr * E,const char * Name)1443 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E,
1444 const char *Name) {
1445 ErrorUnsupported(E, Name);
1446 llvm::Type *ElTy = ConvertType(E->getType());
1447 llvm::Type *Ty = UnqualPtrTy;
1448 return MakeAddrLValue(
1449 Address(llvm::UndefValue::get(Ty), ElTy, CharUnits::One()), E->getType());
1450 }
1451
IsWrappedCXXThis(const Expr * Obj)1452 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) {
1453 const Expr *Base = Obj;
1454 while (!isa<CXXThisExpr>(Base)) {
1455 // The result of a dynamic_cast can be null.
1456 if (isa<CXXDynamicCastExpr>(Base))
1457 return false;
1458
1459 if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1460 Base = CE->getSubExpr();
1461 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1462 Base = PE->getSubExpr();
1463 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1464 if (UO->getOpcode() == UO_Extension)
1465 Base = UO->getSubExpr();
1466 else
1467 return false;
1468 } else {
1469 return false;
1470 }
1471 }
1472 return true;
1473 }
1474
EmitCheckedLValue(const Expr * E,TypeCheckKind TCK)1475 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) {
1476 LValue LV;
1477 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1478 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1479 else
1480 LV = EmitLValue(E);
1481 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1482 SanitizerSet SkippedChecks;
1483 if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1484 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1485 if (IsBaseCXXThis)
1486 SkippedChecks.set(SanitizerKind::Alignment, true);
1487 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1488 SkippedChecks.set(SanitizerKind::Null, true);
1489 }
1490 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(*this), E->getType(),
1491 LV.getAlignment(), SkippedChecks);
1492 }
1493 return LV;
1494 }
1495
1496 /// EmitLValue - Emit code to compute a designator that specifies the location
1497 /// of the expression.
1498 ///
1499 /// This can return one of two things: a simple address or a bitfield reference.
1500 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1501 /// an LLVM pointer type.
1502 ///
1503 /// If this returns a bitfield reference, nothing about the pointee type of the
1504 /// LLVM value is known: For example, it may not be a pointer to an integer.
1505 ///
1506 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1507 /// this method guarantees that the returned pointer type will point to an LLVM
1508 /// type of the same size of the lvalue's type. If the lvalue has a variable
1509 /// length type, this is not possible.
1510 ///
EmitLValue(const Expr * E,KnownNonNull_t IsKnownNonNull)1511 LValue CodeGenFunction::EmitLValue(const Expr *E,
1512 KnownNonNull_t IsKnownNonNull) {
1513 LValue LV = EmitLValueHelper(E, IsKnownNonNull);
1514 if (IsKnownNonNull && !LV.isKnownNonNull())
1515 LV.setKnownNonNull();
1516 return LV;
1517 }
1518
getConstantExprReferredType(const FullExpr * E,const ASTContext & Ctx)1519 static QualType getConstantExprReferredType(const FullExpr *E,
1520 const ASTContext &Ctx) {
1521 const Expr *SE = E->getSubExpr()->IgnoreImplicit();
1522 if (isa<OpaqueValueExpr>(SE))
1523 return SE->getType();
1524 return cast<CallExpr>(SE)->getCallReturnType(Ctx)->getPointeeType();
1525 }
1526
EmitLValueHelper(const Expr * E,KnownNonNull_t IsKnownNonNull)1527 LValue CodeGenFunction::EmitLValueHelper(const Expr *E,
1528 KnownNonNull_t IsKnownNonNull) {
1529 ApplyDebugLocation DL(*this, E);
1530 switch (E->getStmtClass()) {
1531 default: return EmitUnsupportedLValue(E, "l-value expression");
1532
1533 case Expr::ObjCPropertyRefExprClass:
1534 llvm_unreachable("cannot emit a property reference directly");
1535
1536 case Expr::ObjCSelectorExprClass:
1537 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1538 case Expr::ObjCIsaExprClass:
1539 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1540 case Expr::BinaryOperatorClass:
1541 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1542 case Expr::CompoundAssignOperatorClass: {
1543 QualType Ty = E->getType();
1544 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1545 Ty = AT->getValueType();
1546 if (!Ty->isAnyComplexType())
1547 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1548 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1549 }
1550 case Expr::CallExprClass:
1551 case Expr::CXXMemberCallExprClass:
1552 case Expr::CXXOperatorCallExprClass:
1553 case Expr::UserDefinedLiteralClass:
1554 return EmitCallExprLValue(cast<CallExpr>(E));
1555 case Expr::CXXRewrittenBinaryOperatorClass:
1556 return EmitLValue(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm(),
1557 IsKnownNonNull);
1558 case Expr::VAArgExprClass:
1559 return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1560 case Expr::DeclRefExprClass:
1561 return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1562 case Expr::ConstantExprClass: {
1563 const ConstantExpr *CE = cast<ConstantExpr>(E);
1564 if (llvm::Value *Result = ConstantEmitter(*this).tryEmitConstantExpr(CE)) {
1565 QualType RetType = getConstantExprReferredType(CE, getContext());
1566 return MakeNaturalAlignAddrLValue(Result, RetType);
1567 }
1568 return EmitLValue(cast<ConstantExpr>(E)->getSubExpr(), IsKnownNonNull);
1569 }
1570 case Expr::ParenExprClass:
1571 return EmitLValue(cast<ParenExpr>(E)->getSubExpr(), IsKnownNonNull);
1572 case Expr::GenericSelectionExprClass:
1573 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr(),
1574 IsKnownNonNull);
1575 case Expr::PredefinedExprClass:
1576 return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1577 case Expr::StringLiteralClass:
1578 return EmitStringLiteralLValue(cast<StringLiteral>(E));
1579 case Expr::ObjCEncodeExprClass:
1580 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1581 case Expr::PseudoObjectExprClass:
1582 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1583 case Expr::InitListExprClass:
1584 return EmitInitListLValue(cast<InitListExpr>(E));
1585 case Expr::CXXTemporaryObjectExprClass:
1586 case Expr::CXXConstructExprClass:
1587 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1588 case Expr::CXXBindTemporaryExprClass:
1589 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1590 case Expr::CXXUuidofExprClass:
1591 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1592 case Expr::LambdaExprClass:
1593 return EmitAggExprToLValue(E);
1594
1595 case Expr::ExprWithCleanupsClass: {
1596 const auto *cleanups = cast<ExprWithCleanups>(E);
1597 RunCleanupsScope Scope(*this);
1598 LValue LV = EmitLValue(cleanups->getSubExpr(), IsKnownNonNull);
1599 if (LV.isSimple()) {
1600 // Defend against branches out of gnu statement expressions surrounded by
1601 // cleanups.
1602 Address Addr = LV.getAddress(*this);
1603 llvm::Value *V = Addr.getPointer();
1604 Scope.ForceCleanup({&V});
1605 return LValue::MakeAddr(Addr.withPointer(V, Addr.isKnownNonNull()),
1606 LV.getType(), getContext(), LV.getBaseInfo(),
1607 LV.getTBAAInfo());
1608 }
1609 // FIXME: Is it possible to create an ExprWithCleanups that produces a
1610 // bitfield lvalue or some other non-simple lvalue?
1611 return LV;
1612 }
1613
1614 case Expr::CXXDefaultArgExprClass: {
1615 auto *DAE = cast<CXXDefaultArgExpr>(E);
1616 CXXDefaultArgExprScope Scope(*this, DAE);
1617 return EmitLValue(DAE->getExpr(), IsKnownNonNull);
1618 }
1619 case Expr::CXXDefaultInitExprClass: {
1620 auto *DIE = cast<CXXDefaultInitExpr>(E);
1621 CXXDefaultInitExprScope Scope(*this, DIE);
1622 return EmitLValue(DIE->getExpr(), IsKnownNonNull);
1623 }
1624 case Expr::CXXTypeidExprClass:
1625 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1626
1627 case Expr::ObjCMessageExprClass:
1628 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1629 case Expr::ObjCIvarRefExprClass:
1630 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1631 case Expr::StmtExprClass:
1632 return EmitStmtExprLValue(cast<StmtExpr>(E));
1633 case Expr::UnaryOperatorClass:
1634 return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1635 case Expr::ArraySubscriptExprClass:
1636 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1637 case Expr::MatrixSubscriptExprClass:
1638 return EmitMatrixSubscriptExpr(cast<MatrixSubscriptExpr>(E));
1639 case Expr::OMPArraySectionExprClass:
1640 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1641 case Expr::ExtVectorElementExprClass:
1642 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1643 case Expr::CXXThisExprClass:
1644 return MakeAddrLValue(LoadCXXThisAddress(), E->getType());
1645 case Expr::MemberExprClass:
1646 return EmitMemberExpr(cast<MemberExpr>(E));
1647 case Expr::CompoundLiteralExprClass:
1648 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1649 case Expr::ConditionalOperatorClass:
1650 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1651 case Expr::BinaryConditionalOperatorClass:
1652 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1653 case Expr::ChooseExprClass:
1654 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(), IsKnownNonNull);
1655 case Expr::OpaqueValueExprClass:
1656 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1657 case Expr::SubstNonTypeTemplateParmExprClass:
1658 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(),
1659 IsKnownNonNull);
1660 case Expr::ImplicitCastExprClass:
1661 case Expr::CStyleCastExprClass:
1662 case Expr::CXXFunctionalCastExprClass:
1663 case Expr::CXXStaticCastExprClass:
1664 case Expr::CXXDynamicCastExprClass:
1665 case Expr::CXXReinterpretCastExprClass:
1666 case Expr::CXXConstCastExprClass:
1667 case Expr::CXXAddrspaceCastExprClass:
1668 case Expr::ObjCBridgedCastExprClass:
1669 return EmitCastLValue(cast<CastExpr>(E));
1670
1671 case Expr::MaterializeTemporaryExprClass:
1672 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1673
1674 case Expr::CoawaitExprClass:
1675 return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1676 case Expr::CoyieldExprClass:
1677 return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1678 }
1679 }
1680
1681 /// Given an object of the given canonical type, can we safely copy a
1682 /// value out of it based on its initializer?
isConstantEmittableObjectType(QualType type)1683 static bool isConstantEmittableObjectType(QualType type) {
1684 assert(type.isCanonical());
1685 assert(!type->isReferenceType());
1686
1687 // Must be const-qualified but non-volatile.
1688 Qualifiers qs = type.getLocalQualifiers();
1689 if (!qs.hasConst() || qs.hasVolatile()) return false;
1690
1691 // Otherwise, all object types satisfy this except C++ classes with
1692 // mutable subobjects or non-trivial copy/destroy behavior.
1693 if (const auto *RT = dyn_cast<RecordType>(type))
1694 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1695 if (RD->hasMutableFields() || !RD->isTrivial())
1696 return false;
1697
1698 return true;
1699 }
1700
1701 /// Can we constant-emit a load of a reference to a variable of the
1702 /// given type? This is different from predicates like
1703 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1704 /// in situations that don't necessarily satisfy the language's rules
1705 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1706 /// to do this with const float variables even if those variables
1707 /// aren't marked 'constexpr'.
1708 enum ConstantEmissionKind {
1709 CEK_None,
1710 CEK_AsReferenceOnly,
1711 CEK_AsValueOrReference,
1712 CEK_AsValueOnly
1713 };
checkVarTypeForConstantEmission(QualType type)1714 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) {
1715 type = type.getCanonicalType();
1716 if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1717 if (isConstantEmittableObjectType(ref->getPointeeType()))
1718 return CEK_AsValueOrReference;
1719 return CEK_AsReferenceOnly;
1720 }
1721 if (isConstantEmittableObjectType(type))
1722 return CEK_AsValueOnly;
1723 return CEK_None;
1724 }
1725
1726 /// Try to emit a reference to the given value without producing it as
1727 /// an l-value. This is just an optimization, but it avoids us needing
1728 /// to emit global copies of variables if they're named without triggering
1729 /// a formal use in a context where we can't emit a direct reference to them,
1730 /// for instance if a block or lambda or a member of a local class uses a
1731 /// const int variable or constexpr variable from an enclosing function.
1732 CodeGenFunction::ConstantEmission
tryEmitAsConstant(DeclRefExpr * refExpr)1733 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) {
1734 ValueDecl *value = refExpr->getDecl();
1735
1736 // The value needs to be an enum constant or a constant variable.
1737 ConstantEmissionKind CEK;
1738 if (isa<ParmVarDecl>(value)) {
1739 CEK = CEK_None;
1740 } else if (auto *var = dyn_cast<VarDecl>(value)) {
1741 CEK = checkVarTypeForConstantEmission(var->getType());
1742 } else if (isa<EnumConstantDecl>(value)) {
1743 CEK = CEK_AsValueOnly;
1744 } else {
1745 CEK = CEK_None;
1746 }
1747 if (CEK == CEK_None) return ConstantEmission();
1748
1749 Expr::EvalResult result;
1750 bool resultIsReference;
1751 QualType resultType;
1752
1753 // It's best to evaluate all the way as an r-value if that's permitted.
1754 if (CEK != CEK_AsReferenceOnly &&
1755 refExpr->EvaluateAsRValue(result, getContext())) {
1756 resultIsReference = false;
1757 resultType = refExpr->getType();
1758
1759 // Otherwise, try to evaluate as an l-value.
1760 } else if (CEK != CEK_AsValueOnly &&
1761 refExpr->EvaluateAsLValue(result, getContext())) {
1762 resultIsReference = true;
1763 resultType = value->getType();
1764
1765 // Failure.
1766 } else {
1767 return ConstantEmission();
1768 }
1769
1770 // In any case, if the initializer has side-effects, abandon ship.
1771 if (result.HasSideEffects)
1772 return ConstantEmission();
1773
1774 // In CUDA/HIP device compilation, a lambda may capture a reference variable
1775 // referencing a global host variable by copy. In this case the lambda should
1776 // make a copy of the value of the global host variable. The DRE of the
1777 // captured reference variable cannot be emitted as load from the host
1778 // global variable as compile time constant, since the host variable is not
1779 // accessible on device. The DRE of the captured reference variable has to be
1780 // loaded from captures.
1781 if (CGM.getLangOpts().CUDAIsDevice && result.Val.isLValue() &&
1782 refExpr->refersToEnclosingVariableOrCapture()) {
1783 auto *MD = dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl);
1784 if (MD && MD->getParent()->isLambda() &&
1785 MD->getOverloadedOperator() == OO_Call) {
1786 const APValue::LValueBase &base = result.Val.getLValueBase();
1787 if (const ValueDecl *D = base.dyn_cast<const ValueDecl *>()) {
1788 if (const VarDecl *VD = dyn_cast<const VarDecl>(D)) {
1789 if (!VD->hasAttr<CUDADeviceAttr>()) {
1790 return ConstantEmission();
1791 }
1792 }
1793 }
1794 }
1795 }
1796
1797 // Emit as a constant.
1798 auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1799 result.Val, resultType);
1800
1801 // Make sure we emit a debug reference to the global variable.
1802 // This should probably fire even for
1803 if (isa<VarDecl>(value)) {
1804 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1805 EmitDeclRefExprDbgValue(refExpr, result.Val);
1806 } else {
1807 assert(isa<EnumConstantDecl>(value));
1808 EmitDeclRefExprDbgValue(refExpr, result.Val);
1809 }
1810
1811 // If we emitted a reference constant, we need to dereference that.
1812 if (resultIsReference)
1813 return ConstantEmission::forReference(C);
1814
1815 return ConstantEmission::forValue(C);
1816 }
1817
tryToConvertMemberExprToDeclRefExpr(CodeGenFunction & CGF,const MemberExpr * ME)1818 static DeclRefExpr *tryToConvertMemberExprToDeclRefExpr(CodeGenFunction &CGF,
1819 const MemberExpr *ME) {
1820 if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1821 // Try to emit static variable member expressions as DREs.
1822 return DeclRefExpr::Create(
1823 CGF.getContext(), NestedNameSpecifierLoc(), SourceLocation(), VD,
1824 /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1825 ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1826 }
1827 return nullptr;
1828 }
1829
1830 CodeGenFunction::ConstantEmission
tryEmitAsConstant(const MemberExpr * ME)1831 CodeGenFunction::tryEmitAsConstant(const MemberExpr *ME) {
1832 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1833 return tryEmitAsConstant(DRE);
1834 return ConstantEmission();
1835 }
1836
emitScalarConstant(const CodeGenFunction::ConstantEmission & Constant,Expr * E)1837 llvm::Value *CodeGenFunction::emitScalarConstant(
1838 const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1839 assert(Constant && "not a constant");
1840 if (Constant.isReference())
1841 return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1842 E->getExprLoc())
1843 .getScalarVal();
1844 return Constant.getValue();
1845 }
1846
EmitLoadOfScalar(LValue lvalue,SourceLocation Loc)1847 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue,
1848 SourceLocation Loc) {
1849 return EmitLoadOfScalar(lvalue.getAddress(*this), lvalue.isVolatile(),
1850 lvalue.getType(), Loc, lvalue.getBaseInfo(),
1851 lvalue.getTBAAInfo(), lvalue.isNontemporal());
1852 }
1853
hasBooleanRepresentation(QualType Ty)1854 static bool hasBooleanRepresentation(QualType Ty) {
1855 if (Ty->isBooleanType())
1856 return true;
1857
1858 if (const EnumType *ET = Ty->getAs<EnumType>())
1859 return ET->getDecl()->getIntegerType()->isBooleanType();
1860
1861 if (const AtomicType *AT = Ty->getAs<AtomicType>())
1862 return hasBooleanRepresentation(AT->getValueType());
1863
1864 return false;
1865 }
1866
getRangeForType(CodeGenFunction & CGF,QualType Ty,llvm::APInt & Min,llvm::APInt & End,bool StrictEnums,bool IsBool)1867 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty,
1868 llvm::APInt &Min, llvm::APInt &End,
1869 bool StrictEnums, bool IsBool) {
1870 const EnumType *ET = Ty->getAs<EnumType>();
1871 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1872 ET && !ET->getDecl()->isFixed();
1873 if (!IsBool && !IsRegularCPlusPlusEnum)
1874 return false;
1875
1876 if (IsBool) {
1877 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1878 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1879 } else {
1880 const EnumDecl *ED = ET->getDecl();
1881 ED->getValueRange(End, Min);
1882 }
1883 return true;
1884 }
1885
getRangeForLoadFromType(QualType Ty)1886 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1887 llvm::APInt Min, End;
1888 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1889 hasBooleanRepresentation(Ty)))
1890 return nullptr;
1891
1892 llvm::MDBuilder MDHelper(getLLVMContext());
1893 return MDHelper.createRange(Min, End);
1894 }
1895
EmitScalarRangeCheck(llvm::Value * Value,QualType Ty,SourceLocation Loc)1896 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty,
1897 SourceLocation Loc) {
1898 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1899 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1900 if (!HasBoolCheck && !HasEnumCheck)
1901 return false;
1902
1903 bool IsBool = hasBooleanRepresentation(Ty) ||
1904 NSAPI(CGM.getContext()).isObjCBOOLType(Ty);
1905 bool NeedsBoolCheck = HasBoolCheck && IsBool;
1906 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1907 if (!NeedsBoolCheck && !NeedsEnumCheck)
1908 return false;
1909
1910 // Single-bit booleans don't need to be checked. Special-case this to avoid
1911 // a bit width mismatch when handling bitfield values. This is handled by
1912 // EmitFromMemory for the non-bitfield case.
1913 if (IsBool &&
1914 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1915 return false;
1916
1917 llvm::APInt Min, End;
1918 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1919 return true;
1920
1921 auto &Ctx = getLLVMContext();
1922 SanitizerScope SanScope(this);
1923 llvm::Value *Check;
1924 --End;
1925 if (!Min) {
1926 Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1927 } else {
1928 llvm::Value *Upper =
1929 Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1930 llvm::Value *Lower =
1931 Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1932 Check = Builder.CreateAnd(Upper, Lower);
1933 }
1934 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1935 EmitCheckTypeDescriptor(Ty)};
1936 SanitizerMask Kind =
1937 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1938 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1939 StaticArgs, EmitCheckValue(Value));
1940 return true;
1941 }
1942
EmitLoadOfScalar(Address Addr,bool Volatile,QualType Ty,SourceLocation Loc,LValueBaseInfo BaseInfo,TBAAAccessInfo TBAAInfo,bool isNontemporal)1943 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile,
1944 QualType Ty,
1945 SourceLocation Loc,
1946 LValueBaseInfo BaseInfo,
1947 TBAAAccessInfo TBAAInfo,
1948 bool isNontemporal) {
1949 if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr.getPointer()))
1950 if (GV->isThreadLocal())
1951 Addr = Addr.withPointer(Builder.CreateThreadLocalAddress(GV),
1952 NotKnownNonNull);
1953
1954 if (const auto *ClangVecTy = Ty->getAs<VectorType>()) {
1955 // Boolean vectors use `iN` as storage type.
1956 if (ClangVecTy->isExtVectorBoolType()) {
1957 llvm::Type *ValTy = ConvertType(Ty);
1958 unsigned ValNumElems =
1959 cast<llvm::FixedVectorType>(ValTy)->getNumElements();
1960 // Load the `iP` storage object (P is the padded vector size).
1961 auto *RawIntV = Builder.CreateLoad(Addr, Volatile, "load_bits");
1962 const auto *RawIntTy = RawIntV->getType();
1963 assert(RawIntTy->isIntegerTy() && "compressed iN storage for bitvectors");
1964 // Bitcast iP --> <P x i1>.
1965 auto *PaddedVecTy = llvm::FixedVectorType::get(
1966 Builder.getInt1Ty(), RawIntTy->getPrimitiveSizeInBits());
1967 llvm::Value *V = Builder.CreateBitCast(RawIntV, PaddedVecTy);
1968 // Shuffle <P x i1> --> <N x i1> (N is the actual bit size).
1969 V = emitBoolVecConversion(V, ValNumElems, "extractvec");
1970
1971 return EmitFromMemory(V, Ty);
1972 }
1973
1974 // Handle vectors of size 3 like size 4 for better performance.
1975 const llvm::Type *EltTy = Addr.getElementType();
1976 const auto *VTy = cast<llvm::FixedVectorType>(EltTy);
1977
1978 if (!CGM.getCodeGenOpts().PreserveVec3Type && VTy->getNumElements() == 3) {
1979
1980 llvm::VectorType *vec4Ty =
1981 llvm::FixedVectorType::get(VTy->getElementType(), 4);
1982 Address Cast = Addr.withElementType(vec4Ty);
1983 // Now load value.
1984 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1985
1986 // Shuffle vector to get vec3.
1987 V = Builder.CreateShuffleVector(V, ArrayRef<int>{0, 1, 2}, "extractVec");
1988 return EmitFromMemory(V, Ty);
1989 }
1990 }
1991
1992 // Atomic operations have to be done on integral types.
1993 LValue AtomicLValue =
1994 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1995 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1996 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1997 }
1998
1999 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
2000 if (isNontemporal) {
2001 llvm::MDNode *Node = llvm::MDNode::get(
2002 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
2003 Load->setMetadata(llvm::LLVMContext::MD_nontemporal, Node);
2004 }
2005
2006 CGM.DecorateInstructionWithTBAA(Load, TBAAInfo);
2007
2008 if (EmitScalarRangeCheck(Load, Ty, Loc)) {
2009 // In order to prevent the optimizer from throwing away the check, don't
2010 // attach range metadata to the load.
2011 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
2012 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty)) {
2013 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
2014 Load->setMetadata(llvm::LLVMContext::MD_noundef,
2015 llvm::MDNode::get(getLLVMContext(), std::nullopt));
2016 }
2017
2018 return EmitFromMemory(Load, Ty);
2019 }
2020
EmitToMemory(llvm::Value * Value,QualType Ty)2021 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) {
2022 // Bool has a different representation in memory than in registers.
2023 if (hasBooleanRepresentation(Ty)) {
2024 // This should really always be an i1, but sometimes it's already
2025 // an i8, and it's awkward to track those cases down.
2026 if (Value->getType()->isIntegerTy(1))
2027 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
2028 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
2029 "wrong value rep of bool");
2030 }
2031
2032 return Value;
2033 }
2034
EmitFromMemory(llvm::Value * Value,QualType Ty)2035 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
2036 // Bool has a different representation in memory than in registers.
2037 if (hasBooleanRepresentation(Ty)) {
2038 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
2039 "wrong value rep of bool");
2040 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
2041 }
2042 if (Ty->isExtVectorBoolType()) {
2043 const auto *RawIntTy = Value->getType();
2044 // Bitcast iP --> <P x i1>.
2045 auto *PaddedVecTy = llvm::FixedVectorType::get(
2046 Builder.getInt1Ty(), RawIntTy->getPrimitiveSizeInBits());
2047 auto *V = Builder.CreateBitCast(Value, PaddedVecTy);
2048 // Shuffle <P x i1> --> <N x i1> (N is the actual bit size).
2049 llvm::Type *ValTy = ConvertType(Ty);
2050 unsigned ValNumElems = cast<llvm::FixedVectorType>(ValTy)->getNumElements();
2051 return emitBoolVecConversion(V, ValNumElems, "extractvec");
2052 }
2053
2054 return Value;
2055 }
2056
2057 // Convert the pointer of \p Addr to a pointer to a vector (the value type of
2058 // MatrixType), if it points to a array (the memory type of MatrixType).
MaybeConvertMatrixAddress(Address Addr,CodeGenFunction & CGF,bool IsVector=true)2059 static Address MaybeConvertMatrixAddress(Address Addr, CodeGenFunction &CGF,
2060 bool IsVector = true) {
2061 auto *ArrayTy = dyn_cast<llvm::ArrayType>(Addr.getElementType());
2062 if (ArrayTy && IsVector) {
2063 auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
2064 ArrayTy->getNumElements());
2065
2066 return Addr.withElementType(VectorTy);
2067 }
2068 auto *VectorTy = dyn_cast<llvm::VectorType>(Addr.getElementType());
2069 if (VectorTy && !IsVector) {
2070 auto *ArrayTy = llvm::ArrayType::get(
2071 VectorTy->getElementType(),
2072 cast<llvm::FixedVectorType>(VectorTy)->getNumElements());
2073
2074 return Addr.withElementType(ArrayTy);
2075 }
2076
2077 return Addr;
2078 }
2079
2080 // Emit a store of a matrix LValue. This may require casting the original
2081 // pointer to memory address (ArrayType) to a pointer to the value type
2082 // (VectorType).
EmitStoreOfMatrixScalar(llvm::Value * value,LValue lvalue,bool isInit,CodeGenFunction & CGF)2083 static void EmitStoreOfMatrixScalar(llvm::Value *value, LValue lvalue,
2084 bool isInit, CodeGenFunction &CGF) {
2085 Address Addr = MaybeConvertMatrixAddress(lvalue.getAddress(CGF), CGF,
2086 value->getType()->isVectorTy());
2087 CGF.EmitStoreOfScalar(value, Addr, lvalue.isVolatile(), lvalue.getType(),
2088 lvalue.getBaseInfo(), lvalue.getTBAAInfo(), isInit,
2089 lvalue.isNontemporal());
2090 }
2091
EmitStoreOfScalar(llvm::Value * Value,Address Addr,bool Volatile,QualType Ty,LValueBaseInfo BaseInfo,TBAAAccessInfo TBAAInfo,bool isInit,bool isNontemporal)2092 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr,
2093 bool Volatile, QualType Ty,
2094 LValueBaseInfo BaseInfo,
2095 TBAAAccessInfo TBAAInfo,
2096 bool isInit, bool isNontemporal) {
2097 if (auto *GV = dyn_cast<llvm::GlobalValue>(Addr.getPointer()))
2098 if (GV->isThreadLocal())
2099 Addr = Addr.withPointer(Builder.CreateThreadLocalAddress(GV),
2100 NotKnownNonNull);
2101
2102 llvm::Type *SrcTy = Value->getType();
2103 if (const auto *ClangVecTy = Ty->getAs<VectorType>()) {
2104 auto *VecTy = dyn_cast<llvm::FixedVectorType>(SrcTy);
2105 if (VecTy && ClangVecTy->isExtVectorBoolType()) {
2106 auto *MemIntTy = cast<llvm::IntegerType>(Addr.getElementType());
2107 // Expand to the memory bit width.
2108 unsigned MemNumElems = MemIntTy->getPrimitiveSizeInBits();
2109 // <N x i1> --> <P x i1>.
2110 Value = emitBoolVecConversion(Value, MemNumElems, "insertvec");
2111 // <P x i1> --> iP.
2112 Value = Builder.CreateBitCast(Value, MemIntTy);
2113 } else if (!CGM.getCodeGenOpts().PreserveVec3Type) {
2114 // Handle vec3 special.
2115 if (VecTy && cast<llvm::FixedVectorType>(VecTy)->getNumElements() == 3) {
2116 // Our source is a vec3, do a shuffle vector to make it a vec4.
2117 Value = Builder.CreateShuffleVector(Value, ArrayRef<int>{0, 1, 2, -1},
2118 "extractVec");
2119 SrcTy = llvm::FixedVectorType::get(VecTy->getElementType(), 4);
2120 }
2121 if (Addr.getElementType() != SrcTy) {
2122 Addr = Addr.withElementType(SrcTy);
2123 }
2124 }
2125 }
2126
2127 Value = EmitToMemory(Value, Ty);
2128
2129 LValue AtomicLValue =
2130 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
2131 if (Ty->isAtomicType() ||
2132 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
2133 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
2134 return;
2135 }
2136
2137 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
2138 if (isNontemporal) {
2139 llvm::MDNode *Node =
2140 llvm::MDNode::get(Store->getContext(),
2141 llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
2142 Store->setMetadata(llvm::LLVMContext::MD_nontemporal, Node);
2143 }
2144
2145 CGM.DecorateInstructionWithTBAA(Store, TBAAInfo);
2146 }
2147
EmitStoreOfScalar(llvm::Value * value,LValue lvalue,bool isInit)2148 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
2149 bool isInit) {
2150 if (lvalue.getType()->isConstantMatrixType()) {
2151 EmitStoreOfMatrixScalar(value, lvalue, isInit, *this);
2152 return;
2153 }
2154
2155 EmitStoreOfScalar(value, lvalue.getAddress(*this), lvalue.isVolatile(),
2156 lvalue.getType(), lvalue.getBaseInfo(),
2157 lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
2158 }
2159
2160 // Emit a load of a LValue of matrix type. This may require casting the pointer
2161 // to memory address (ArrayType) to a pointer to the value type (VectorType).
EmitLoadOfMatrixLValue(LValue LV,SourceLocation Loc,CodeGenFunction & CGF)2162 static RValue EmitLoadOfMatrixLValue(LValue LV, SourceLocation Loc,
2163 CodeGenFunction &CGF) {
2164 assert(LV.getType()->isConstantMatrixType());
2165 Address Addr = MaybeConvertMatrixAddress(LV.getAddress(CGF), CGF);
2166 LV.setAddress(Addr);
2167 return RValue::get(CGF.EmitLoadOfScalar(LV, Loc));
2168 }
2169
2170 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
2171 /// method emits the address of the lvalue, then loads the result as an rvalue,
2172 /// returning the rvalue.
EmitLoadOfLValue(LValue LV,SourceLocation Loc)2173 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) {
2174 if (LV.isObjCWeak()) {
2175 // load of a __weak object.
2176 Address AddrWeakObj = LV.getAddress(*this);
2177 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this,
2178 AddrWeakObj));
2179 }
2180 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
2181 // In MRC mode, we do a load+autorelease.
2182 if (!getLangOpts().ObjCAutoRefCount) {
2183 return RValue::get(EmitARCLoadWeak(LV.getAddress(*this)));
2184 }
2185
2186 // In ARC mode, we load retained and then consume the value.
2187 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress(*this));
2188 Object = EmitObjCConsumeObject(LV.getType(), Object);
2189 return RValue::get(Object);
2190 }
2191
2192 if (LV.isSimple()) {
2193 assert(!LV.getType()->isFunctionType());
2194
2195 if (LV.getType()->isConstantMatrixType())
2196 return EmitLoadOfMatrixLValue(LV, Loc, *this);
2197
2198 // Everything needs a load.
2199 return RValue::get(EmitLoadOfScalar(LV, Loc));
2200 }
2201
2202 if (LV.isVectorElt()) {
2203 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
2204 LV.isVolatileQualified());
2205 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
2206 "vecext"));
2207 }
2208
2209 // If this is a reference to a subset of the elements of a vector, either
2210 // shuffle the input or extract/insert them as appropriate.
2211 if (LV.isExtVectorElt()) {
2212 return EmitLoadOfExtVectorElementLValue(LV);
2213 }
2214
2215 // Global Register variables always invoke intrinsics
2216 if (LV.isGlobalReg())
2217 return EmitLoadOfGlobalRegLValue(LV);
2218
2219 if (LV.isMatrixElt()) {
2220 llvm::Value *Idx = LV.getMatrixIdx();
2221 if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
2222 const auto *const MatTy = LV.getType()->castAs<ConstantMatrixType>();
2223 llvm::MatrixBuilder MB(Builder);
2224 MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
2225 }
2226 llvm::LoadInst *Load =
2227 Builder.CreateLoad(LV.getMatrixAddress(), LV.isVolatileQualified());
2228 return RValue::get(Builder.CreateExtractElement(Load, Idx, "matrixext"));
2229 }
2230
2231 assert(LV.isBitField() && "Unknown LValue type!");
2232 return EmitLoadOfBitfieldLValue(LV, Loc);
2233 }
2234
EmitLoadOfBitfieldLValue(LValue LV,SourceLocation Loc)2235 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV,
2236 SourceLocation Loc) {
2237 const CGBitFieldInfo &Info = LV.getBitFieldInfo();
2238
2239 // Get the output type.
2240 llvm::Type *ResLTy = ConvertType(LV.getType());
2241
2242 Address Ptr = LV.getBitFieldAddress();
2243 llvm::Value *Val =
2244 Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
2245
2246 bool UseVolatile = LV.isVolatileQualified() &&
2247 Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
2248 const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
2249 const unsigned StorageSize =
2250 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
2251 if (Info.IsSigned) {
2252 assert(static_cast<unsigned>(Offset + Info.Size) <= StorageSize);
2253 unsigned HighBits = StorageSize - Offset - Info.Size;
2254 if (HighBits)
2255 Val = Builder.CreateShl(Val, HighBits, "bf.shl");
2256 if (Offset + HighBits)
2257 Val = Builder.CreateAShr(Val, Offset + HighBits, "bf.ashr");
2258 } else {
2259 if (Offset)
2260 Val = Builder.CreateLShr(Val, Offset, "bf.lshr");
2261 if (static_cast<unsigned>(Offset) + Info.Size < StorageSize)
2262 Val = Builder.CreateAnd(
2263 Val, llvm::APInt::getLowBitsSet(StorageSize, Info.Size), "bf.clear");
2264 }
2265 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
2266 EmitScalarRangeCheck(Val, LV.getType(), Loc);
2267 return RValue::get(Val);
2268 }
2269
2270 // If this is a reference to a subset of the elements of a vector, create an
2271 // appropriate shufflevector.
EmitLoadOfExtVectorElementLValue(LValue LV)2272 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
2273 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(),
2274 LV.isVolatileQualified());
2275
2276 // HLSL allows treating scalars as one-element vectors. Converting the scalar
2277 // IR value to a vector here allows the rest of codegen to behave as normal.
2278 if (getLangOpts().HLSL && !Vec->getType()->isVectorTy()) {
2279 llvm::Type *DstTy = llvm::FixedVectorType::get(Vec->getType(), 1);
2280 llvm::Value *Zero = llvm::Constant::getNullValue(CGM.Int64Ty);
2281 Vec = Builder.CreateInsertElement(DstTy, Vec, Zero, "cast.splat");
2282 }
2283
2284 const llvm::Constant *Elts = LV.getExtVectorElts();
2285
2286 // If the result of the expression is a non-vector type, we must be extracting
2287 // a single element. Just codegen as an extractelement.
2288 const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
2289 if (!ExprVT) {
2290 unsigned InIdx = getAccessedFieldNo(0, Elts);
2291 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2292 return RValue::get(Builder.CreateExtractElement(Vec, Elt));
2293 }
2294
2295 // Always use shuffle vector to try to retain the original program structure
2296 unsigned NumResultElts = ExprVT->getNumElements();
2297
2298 SmallVector<int, 4> Mask;
2299 for (unsigned i = 0; i != NumResultElts; ++i)
2300 Mask.push_back(getAccessedFieldNo(i, Elts));
2301
2302 Vec = Builder.CreateShuffleVector(Vec, Mask);
2303 return RValue::get(Vec);
2304 }
2305
2306 /// Generates lvalue for partial ext_vector access.
EmitExtVectorElementLValue(LValue LV)2307 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) {
2308 Address VectorAddress = LV.getExtVectorAddress();
2309 QualType EQT = LV.getType()->castAs<VectorType>()->getElementType();
2310 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
2311
2312 Address CastToPointerElement = VectorAddress.withElementType(VectorElementTy);
2313
2314 const llvm::Constant *Elts = LV.getExtVectorElts();
2315 unsigned ix = getAccessedFieldNo(0, Elts);
2316
2317 Address VectorBasePtrPlusIx =
2318 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
2319 "vector.elt");
2320
2321 return VectorBasePtrPlusIx;
2322 }
2323
2324 /// Load of global gamed gegisters are always calls to intrinsics.
EmitLoadOfGlobalRegLValue(LValue LV)2325 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) {
2326 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
2327 "Bad type for register variable");
2328 llvm::MDNode *RegName = cast<llvm::MDNode>(
2329 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
2330
2331 // We accept integer and pointer types only
2332 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
2333 llvm::Type *Ty = OrigTy;
2334 if (OrigTy->isPointerTy())
2335 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2336 llvm::Type *Types[] = { Ty };
2337
2338 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
2339 llvm::Value *Call = Builder.CreateCall(
2340 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
2341 if (OrigTy->isPointerTy())
2342 Call = Builder.CreateIntToPtr(Call, OrigTy);
2343 return RValue::get(Call);
2344 }
2345
2346 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
2347 /// lvalue, where both are guaranteed to the have the same type, and that type
2348 /// is 'Ty'.
EmitStoreThroughLValue(RValue Src,LValue Dst,bool isInit)2349 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst,
2350 bool isInit) {
2351 if (!Dst.isSimple()) {
2352 if (Dst.isVectorElt()) {
2353 // Read/modify/write the vector, inserting the new element.
2354 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(),
2355 Dst.isVolatileQualified());
2356 auto *IRStoreTy = dyn_cast<llvm::IntegerType>(Vec->getType());
2357 if (IRStoreTy) {
2358 auto *IRVecTy = llvm::FixedVectorType::get(
2359 Builder.getInt1Ty(), IRStoreTy->getPrimitiveSizeInBits());
2360 Vec = Builder.CreateBitCast(Vec, IRVecTy);
2361 // iN --> <N x i1>.
2362 }
2363 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
2364 Dst.getVectorIdx(), "vecins");
2365 if (IRStoreTy) {
2366 // <N x i1> --> <iN>.
2367 Vec = Builder.CreateBitCast(Vec, IRStoreTy);
2368 }
2369 Builder.CreateStore(Vec, Dst.getVectorAddress(),
2370 Dst.isVolatileQualified());
2371 return;
2372 }
2373
2374 // If this is an update of extended vector elements, insert them as
2375 // appropriate.
2376 if (Dst.isExtVectorElt())
2377 return EmitStoreThroughExtVectorComponentLValue(Src, Dst);
2378
2379 if (Dst.isGlobalReg())
2380 return EmitStoreThroughGlobalRegLValue(Src, Dst);
2381
2382 if (Dst.isMatrixElt()) {
2383 llvm::Value *Idx = Dst.getMatrixIdx();
2384 if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
2385 const auto *const MatTy = Dst.getType()->castAs<ConstantMatrixType>();
2386 llvm::MatrixBuilder MB(Builder);
2387 MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
2388 }
2389 llvm::Instruction *Load = Builder.CreateLoad(Dst.getMatrixAddress());
2390 llvm::Value *Vec =
2391 Builder.CreateInsertElement(Load, Src.getScalarVal(), Idx, "matins");
2392 Builder.CreateStore(Vec, Dst.getMatrixAddress(),
2393 Dst.isVolatileQualified());
2394 return;
2395 }
2396
2397 assert(Dst.isBitField() && "Unknown LValue type");
2398 return EmitStoreThroughBitfieldLValue(Src, Dst);
2399 }
2400
2401 // There's special magic for assigning into an ARC-qualified l-value.
2402 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
2403 switch (Lifetime) {
2404 case Qualifiers::OCL_None:
2405 llvm_unreachable("present but none");
2406
2407 case Qualifiers::OCL_ExplicitNone:
2408 // nothing special
2409 break;
2410
2411 case Qualifiers::OCL_Strong:
2412 if (isInit) {
2413 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
2414 break;
2415 }
2416 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
2417 return;
2418
2419 case Qualifiers::OCL_Weak:
2420 if (isInit)
2421 // Initialize and then skip the primitive store.
2422 EmitARCInitWeak(Dst.getAddress(*this), Src.getScalarVal());
2423 else
2424 EmitARCStoreWeak(Dst.getAddress(*this), Src.getScalarVal(),
2425 /*ignore*/ true);
2426 return;
2427
2428 case Qualifiers::OCL_Autoreleasing:
2429 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(),
2430 Src.getScalarVal()));
2431 // fall into the normal path
2432 break;
2433 }
2434 }
2435
2436 if (Dst.isObjCWeak() && !Dst.isNonGC()) {
2437 // load of a __weak object.
2438 Address LvalueDst = Dst.getAddress(*this);
2439 llvm::Value *src = Src.getScalarVal();
2440 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
2441 return;
2442 }
2443
2444 if (Dst.isObjCStrong() && !Dst.isNonGC()) {
2445 // load of a __strong object.
2446 Address LvalueDst = Dst.getAddress(*this);
2447 llvm::Value *src = Src.getScalarVal();
2448 if (Dst.isObjCIvar()) {
2449 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2450 llvm::Type *ResultType = IntPtrTy;
2451 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp());
2452 llvm::Value *RHS = dst.getPointer();
2453 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2454 llvm::Value *LHS =
2455 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
2456 "sub.ptr.lhs.cast");
2457 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2458 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2459 BytesBetween);
2460 } else if (Dst.isGlobalObjCRef()) {
2461 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2462 Dst.isThreadLocalRef());
2463 }
2464 else
2465 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2466 return;
2467 }
2468
2469 assert(Src.isScalar() && "Can't emit an agg store with this method");
2470 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2471 }
2472
EmitStoreThroughBitfieldLValue(RValue Src,LValue Dst,llvm::Value ** Result)2473 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
2474 llvm::Value **Result) {
2475 const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2476 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2477 Address Ptr = Dst.getBitFieldAddress();
2478
2479 // Get the source value, truncated to the width of the bit-field.
2480 llvm::Value *SrcVal = Src.getScalarVal();
2481
2482 // Cast the source to the storage type and shift it into place.
2483 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2484 /*isSigned=*/false);
2485 llvm::Value *MaskedVal = SrcVal;
2486
2487 const bool UseVolatile =
2488 CGM.getCodeGenOpts().AAPCSBitfieldWidth && Dst.isVolatileQualified() &&
2489 Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
2490 const unsigned StorageSize =
2491 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
2492 const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
2493 // See if there are other bits in the bitfield's storage we'll need to load
2494 // and mask together with source before storing.
2495 if (StorageSize != Info.Size) {
2496 assert(StorageSize > Info.Size && "Invalid bitfield size.");
2497 llvm::Value *Val =
2498 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2499
2500 // Mask the source value as needed.
2501 if (!hasBooleanRepresentation(Dst.getType()))
2502 SrcVal = Builder.CreateAnd(
2503 SrcVal, llvm::APInt::getLowBitsSet(StorageSize, Info.Size),
2504 "bf.value");
2505 MaskedVal = SrcVal;
2506 if (Offset)
2507 SrcVal = Builder.CreateShl(SrcVal, Offset, "bf.shl");
2508
2509 // Mask out the original value.
2510 Val = Builder.CreateAnd(
2511 Val, ~llvm::APInt::getBitsSet(StorageSize, Offset, Offset + Info.Size),
2512 "bf.clear");
2513
2514 // Or together the unchanged values and the source value.
2515 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2516 } else {
2517 assert(Offset == 0);
2518 // According to the AACPS:
2519 // When a volatile bit-field is written, and its container does not overlap
2520 // with any non-bit-field member, its container must be read exactly once
2521 // and written exactly once using the access width appropriate to the type
2522 // of the container. The two accesses are not atomic.
2523 if (Dst.isVolatileQualified() && isAAPCS(CGM.getTarget()) &&
2524 CGM.getCodeGenOpts().ForceAAPCSBitfieldLoad)
2525 Builder.CreateLoad(Ptr, true, "bf.load");
2526 }
2527
2528 // Write the new value back out.
2529 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2530
2531 // Return the new value of the bit-field, if requested.
2532 if (Result) {
2533 llvm::Value *ResultVal = MaskedVal;
2534
2535 // Sign extend the value if needed.
2536 if (Info.IsSigned) {
2537 assert(Info.Size <= StorageSize);
2538 unsigned HighBits = StorageSize - Info.Size;
2539 if (HighBits) {
2540 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2541 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2542 }
2543 }
2544
2545 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2546 "bf.result.cast");
2547 *Result = EmitFromMemory(ResultVal, Dst.getType());
2548 }
2549 }
2550
EmitStoreThroughExtVectorComponentLValue(RValue Src,LValue Dst)2551 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src,
2552 LValue Dst) {
2553 // HLSL allows storing to scalar values through ExtVector component LValues.
2554 // To support this we need to handle the case where the destination address is
2555 // a scalar.
2556 Address DstAddr = Dst.getExtVectorAddress();
2557 if (!DstAddr.getElementType()->isVectorTy()) {
2558 assert(!Dst.getType()->isVectorType() &&
2559 "this should only occur for non-vector l-values");
2560 Builder.CreateStore(Src.getScalarVal(), DstAddr, Dst.isVolatileQualified());
2561 return;
2562 }
2563
2564 // This access turns into a read/modify/write of the vector. Load the input
2565 // value now.
2566 llvm::Value *Vec = Builder.CreateLoad(DstAddr, Dst.isVolatileQualified());
2567 const llvm::Constant *Elts = Dst.getExtVectorElts();
2568
2569 llvm::Value *SrcVal = Src.getScalarVal();
2570
2571 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2572 unsigned NumSrcElts = VTy->getNumElements();
2573 unsigned NumDstElts =
2574 cast<llvm::FixedVectorType>(Vec->getType())->getNumElements();
2575 if (NumDstElts == NumSrcElts) {
2576 // Use shuffle vector is the src and destination are the same number of
2577 // elements and restore the vector mask since it is on the side it will be
2578 // stored.
2579 SmallVector<int, 4> Mask(NumDstElts);
2580 for (unsigned i = 0; i != NumSrcElts; ++i)
2581 Mask[getAccessedFieldNo(i, Elts)] = i;
2582
2583 Vec = Builder.CreateShuffleVector(SrcVal, Mask);
2584 } else if (NumDstElts > NumSrcElts) {
2585 // Extended the source vector to the same length and then shuffle it
2586 // into the destination.
2587 // FIXME: since we're shuffling with undef, can we just use the indices
2588 // into that? This could be simpler.
2589 SmallVector<int, 4> ExtMask;
2590 for (unsigned i = 0; i != NumSrcElts; ++i)
2591 ExtMask.push_back(i);
2592 ExtMask.resize(NumDstElts, -1);
2593 llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal, ExtMask);
2594 // build identity
2595 SmallVector<int, 4> Mask;
2596 for (unsigned i = 0; i != NumDstElts; ++i)
2597 Mask.push_back(i);
2598
2599 // When the vector size is odd and .odd or .hi is used, the last element
2600 // of the Elts constant array will be one past the size of the vector.
2601 // Ignore the last element here, if it is greater than the mask size.
2602 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2603 NumSrcElts--;
2604
2605 // modify when what gets shuffled in
2606 for (unsigned i = 0; i != NumSrcElts; ++i)
2607 Mask[getAccessedFieldNo(i, Elts)] = i + NumDstElts;
2608 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, Mask);
2609 } else {
2610 // We should never shorten the vector
2611 llvm_unreachable("unexpected shorten vector length");
2612 }
2613 } else {
2614 // If the Src is a scalar (not a vector), and the target is a vector it must
2615 // be updating one element.
2616 unsigned InIdx = getAccessedFieldNo(0, Elts);
2617 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2618 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2619 }
2620
2621 Builder.CreateStore(Vec, Dst.getExtVectorAddress(),
2622 Dst.isVolatileQualified());
2623 }
2624
2625 /// Store of global named registers are always calls to intrinsics.
EmitStoreThroughGlobalRegLValue(RValue Src,LValue Dst)2626 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) {
2627 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2628 "Bad type for register variable");
2629 llvm::MDNode *RegName = cast<llvm::MDNode>(
2630 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2631 assert(RegName && "Register LValue is not metadata");
2632
2633 // We accept integer and pointer types only
2634 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2635 llvm::Type *Ty = OrigTy;
2636 if (OrigTy->isPointerTy())
2637 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2638 llvm::Type *Types[] = { Ty };
2639
2640 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2641 llvm::Value *Value = Src.getScalarVal();
2642 if (OrigTy->isPointerTy())
2643 Value = Builder.CreatePtrToInt(Value, Ty);
2644 Builder.CreateCall(
2645 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2646 }
2647
2648 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2649 // generating write-barries API. It is currently a global, ivar,
2650 // or neither.
setObjCGCLValueClass(const ASTContext & Ctx,const Expr * E,LValue & LV,bool IsMemberAccess=false)2651 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2652 LValue &LV,
2653 bool IsMemberAccess=false) {
2654 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2655 return;
2656
2657 if (isa<ObjCIvarRefExpr>(E)) {
2658 QualType ExpTy = E->getType();
2659 if (IsMemberAccess && ExpTy->isPointerType()) {
2660 // If ivar is a structure pointer, assigning to field of
2661 // this struct follows gcc's behavior and makes it a non-ivar
2662 // writer-barrier conservatively.
2663 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2664 if (ExpTy->isRecordType()) {
2665 LV.setObjCIvar(false);
2666 return;
2667 }
2668 }
2669 LV.setObjCIvar(true);
2670 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2671 LV.setBaseIvarExp(Exp->getBase());
2672 LV.setObjCArray(E->getType()->isArrayType());
2673 return;
2674 }
2675
2676 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2677 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2678 if (VD->hasGlobalStorage()) {
2679 LV.setGlobalObjCRef(true);
2680 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2681 }
2682 }
2683 LV.setObjCArray(E->getType()->isArrayType());
2684 return;
2685 }
2686
2687 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2688 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2689 return;
2690 }
2691
2692 if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2693 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2694 if (LV.isObjCIvar()) {
2695 // If cast is to a structure pointer, follow gcc's behavior and make it
2696 // a non-ivar write-barrier.
2697 QualType ExpTy = E->getType();
2698 if (ExpTy->isPointerType())
2699 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2700 if (ExpTy->isRecordType())
2701 LV.setObjCIvar(false);
2702 }
2703 return;
2704 }
2705
2706 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2707 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2708 return;
2709 }
2710
2711 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2712 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2713 return;
2714 }
2715
2716 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2717 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2718 return;
2719 }
2720
2721 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2722 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2723 return;
2724 }
2725
2726 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2727 setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2728 if (LV.isObjCIvar() && !LV.isObjCArray())
2729 // Using array syntax to assigning to what an ivar points to is not
2730 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2731 LV.setObjCIvar(false);
2732 else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2733 // Using array syntax to assigning to what global points to is not
2734 // same as assigning to the global itself. {id *G;} G[i] = 0;
2735 LV.setGlobalObjCRef(false);
2736 return;
2737 }
2738
2739 if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2740 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2741 // We don't know if member is an 'ivar', but this flag is looked at
2742 // only in the context of LV.isObjCIvar().
2743 LV.setObjCArray(E->getType()->isArrayType());
2744 return;
2745 }
2746 }
2747
EmitThreadPrivateVarDeclLValue(CodeGenFunction & CGF,const VarDecl * VD,QualType T,Address Addr,llvm::Type * RealVarTy,SourceLocation Loc)2748 static LValue EmitThreadPrivateVarDeclLValue(
2749 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2750 llvm::Type *RealVarTy, SourceLocation Loc) {
2751 if (CGF.CGM.getLangOpts().OpenMPIRBuilder)
2752 Addr = CodeGenFunction::OMPBuilderCBHelpers::getAddrOfThreadPrivate(
2753 CGF, VD, Addr, Loc);
2754 else
2755 Addr =
2756 CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2757
2758 Addr = Addr.withElementType(RealVarTy);
2759 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2760 }
2761
emitDeclTargetVarDeclLValue(CodeGenFunction & CGF,const VarDecl * VD,QualType T)2762 static Address emitDeclTargetVarDeclLValue(CodeGenFunction &CGF,
2763 const VarDecl *VD, QualType T) {
2764 std::optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res =
2765 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2766 // Return an invalid address if variable is MT_To (or MT_Enter starting with
2767 // OpenMP 5.2) and unified memory is not enabled. For all other cases: MT_Link
2768 // and MT_To (or MT_Enter) with unified memory, return a valid address.
2769 if (!Res || ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
2770 *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
2771 !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory()))
2772 return Address::invalid();
2773 assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2774 ((*Res == OMPDeclareTargetDeclAttr::MT_To ||
2775 *Res == OMPDeclareTargetDeclAttr::MT_Enter) &&
2776 CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) &&
2777 "Expected link clause OR to clause with unified memory enabled.");
2778 QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2779 Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD);
2780 return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2781 }
2782
2783 Address
EmitLoadOfReference(LValue RefLVal,LValueBaseInfo * PointeeBaseInfo,TBAAAccessInfo * PointeeTBAAInfo)2784 CodeGenFunction::EmitLoadOfReference(LValue RefLVal,
2785 LValueBaseInfo *PointeeBaseInfo,
2786 TBAAAccessInfo *PointeeTBAAInfo) {
2787 llvm::LoadInst *Load =
2788 Builder.CreateLoad(RefLVal.getAddress(*this), RefLVal.isVolatile());
2789 CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo());
2790
2791 QualType PointeeType = RefLVal.getType()->getPointeeType();
2792 CharUnits Align = CGM.getNaturalTypeAlignment(
2793 PointeeType, PointeeBaseInfo, PointeeTBAAInfo,
2794 /* forPointeeType= */ true);
2795 return Address(Load, ConvertTypeForMem(PointeeType), Align);
2796 }
2797
EmitLoadOfReferenceLValue(LValue RefLVal)2798 LValue CodeGenFunction::EmitLoadOfReferenceLValue(LValue RefLVal) {
2799 LValueBaseInfo PointeeBaseInfo;
2800 TBAAAccessInfo PointeeTBAAInfo;
2801 Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2802 &PointeeTBAAInfo);
2803 return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2804 PointeeBaseInfo, PointeeTBAAInfo);
2805 }
2806
EmitLoadOfPointer(Address Ptr,const PointerType * PtrTy,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo)2807 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
2808 const PointerType *PtrTy,
2809 LValueBaseInfo *BaseInfo,
2810 TBAAAccessInfo *TBAAInfo) {
2811 llvm::Value *Addr = Builder.CreateLoad(Ptr);
2812 return Address(Addr, ConvertTypeForMem(PtrTy->getPointeeType()),
2813 CGM.getNaturalTypeAlignment(PtrTy->getPointeeType(), BaseInfo,
2814 TBAAInfo,
2815 /*forPointeeType=*/true));
2816 }
2817
EmitLoadOfPointerLValue(Address PtrAddr,const PointerType * PtrTy)2818 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
2819 const PointerType *PtrTy) {
2820 LValueBaseInfo BaseInfo;
2821 TBAAAccessInfo TBAAInfo;
2822 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2823 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2824 }
2825
EmitGlobalVarDeclLValue(CodeGenFunction & CGF,const Expr * E,const VarDecl * VD)2826 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
2827 const Expr *E, const VarDecl *VD) {
2828 QualType T = E->getType();
2829
2830 // If it's thread_local, emit a call to its wrapper function instead.
2831 if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2832 CGF.CGM.getCXXABI().usesThreadWrapperFunction(VD))
2833 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2834 // Check if the variable is marked as declare target with link clause in
2835 // device codegen.
2836 if (CGF.getLangOpts().OpenMPIsTargetDevice) {
2837 Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2838 if (Addr.isValid())
2839 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2840 }
2841
2842 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2843
2844 if (VD->getTLSKind() != VarDecl::TLS_None)
2845 V = CGF.Builder.CreateThreadLocalAddress(V);
2846
2847 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2848 CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2849 Address Addr(V, RealVarTy, Alignment);
2850 // Emit reference to the private copy of the variable if it is an OpenMP
2851 // threadprivate variable.
2852 if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2853 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2854 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2855 E->getExprLoc());
2856 }
2857 LValue LV = VD->getType()->isReferenceType() ?
2858 CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2859 AlignmentSource::Decl) :
2860 CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2861 setObjCGCLValueClass(CGF.getContext(), E, LV);
2862 return LV;
2863 }
2864
EmitFunctionDeclPointer(CodeGenModule & CGM,GlobalDecl GD)2865 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2866 GlobalDecl GD) {
2867 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2868 if (FD->hasAttr<WeakRefAttr>()) {
2869 ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2870 return aliasee.getPointer();
2871 }
2872
2873 llvm::Constant *V = CGM.GetAddrOfFunction(GD);
2874 return V;
2875 }
2876
EmitFunctionDeclLValue(CodeGenFunction & CGF,const Expr * E,GlobalDecl GD)2877 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF, const Expr *E,
2878 GlobalDecl GD) {
2879 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2880 llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, GD);
2881 CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2882 return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2883 AlignmentSource::Decl);
2884 }
2885
EmitCapturedFieldLValue(CodeGenFunction & CGF,const FieldDecl * FD,llvm::Value * ThisValue)2886 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
2887 llvm::Value *ThisValue) {
2888
2889 return CGF.EmitLValueForLambdaField(FD, ThisValue);
2890 }
2891
2892 /// Named Registers are named metadata pointing to the register name
2893 /// which will be read from/written to as an argument to the intrinsic
2894 /// @llvm.read/write_register.
2895 /// So far, only the name is being passed down, but other options such as
2896 /// register type, allocation type or even optimization options could be
2897 /// passed down via the metadata node.
EmitGlobalNamedRegister(const VarDecl * VD,CodeGenModule & CGM)2898 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) {
2899 SmallString<64> Name("llvm.named.register.");
2900 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2901 assert(Asm->getLabel().size() < 64-Name.size() &&
2902 "Register name too big");
2903 Name.append(Asm->getLabel());
2904 llvm::NamedMDNode *M =
2905 CGM.getModule().getOrInsertNamedMetadata(Name);
2906 if (M->getNumOperands() == 0) {
2907 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2908 Asm->getLabel());
2909 llvm::Metadata *Ops[] = {Str};
2910 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2911 }
2912
2913 CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2914
2915 llvm::Value *Ptr =
2916 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2917 return LValue::MakeGlobalReg(Ptr, Alignment, VD->getType());
2918 }
2919
2920 /// Determine whether we can emit a reference to \p VD from the current
2921 /// context, despite not necessarily having seen an odr-use of the variable in
2922 /// this context.
canEmitSpuriousReferenceToVariable(CodeGenFunction & CGF,const DeclRefExpr * E,const VarDecl * VD)2923 static bool canEmitSpuriousReferenceToVariable(CodeGenFunction &CGF,
2924 const DeclRefExpr *E,
2925 const VarDecl *VD) {
2926 // For a variable declared in an enclosing scope, do not emit a spurious
2927 // reference even if we have a capture, as that will emit an unwarranted
2928 // reference to our capture state, and will likely generate worse code than
2929 // emitting a local copy.
2930 if (E->refersToEnclosingVariableOrCapture())
2931 return false;
2932
2933 // For a local declaration declared in this function, we can always reference
2934 // it even if we don't have an odr-use.
2935 if (VD->hasLocalStorage()) {
2936 return VD->getDeclContext() ==
2937 dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2938 }
2939
2940 // For a global declaration, we can emit a reference to it if we know
2941 // for sure that we are able to emit a definition of it.
2942 VD = VD->getDefinition(CGF.getContext());
2943 if (!VD)
2944 return false;
2945
2946 // Don't emit a spurious reference if it might be to a variable that only
2947 // exists on a different device / target.
2948 // FIXME: This is unnecessarily broad. Check whether this would actually be a
2949 // cross-target reference.
2950 if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2951 CGF.getLangOpts().OpenCL) {
2952 return false;
2953 }
2954
2955 // We can emit a spurious reference only if the linkage implies that we'll
2956 // be emitting a non-interposable symbol that will be retained until link
2957 // time.
2958 switch (CGF.CGM.getLLVMLinkageVarDefinition(VD)) {
2959 case llvm::GlobalValue::ExternalLinkage:
2960 case llvm::GlobalValue::LinkOnceODRLinkage:
2961 case llvm::GlobalValue::WeakODRLinkage:
2962 case llvm::GlobalValue::InternalLinkage:
2963 case llvm::GlobalValue::PrivateLinkage:
2964 return true;
2965 default:
2966 return false;
2967 }
2968 }
2969
EmitDeclRefLValue(const DeclRefExpr * E)2970 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) {
2971 const NamedDecl *ND = E->getDecl();
2972 QualType T = E->getType();
2973
2974 assert(E->isNonOdrUse() != NOUR_Unevaluated &&
2975 "should not emit an unevaluated operand");
2976
2977 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2978 // Global Named registers access via intrinsics only
2979 if (VD->getStorageClass() == SC_Register &&
2980 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2981 return EmitGlobalNamedRegister(VD, CGM);
2982
2983 // If this DeclRefExpr does not constitute an odr-use of the variable,
2984 // we're not permitted to emit a reference to it in general, and it might
2985 // not be captured if capture would be necessary for a use. Emit the
2986 // constant value directly instead.
2987 if (E->isNonOdrUse() == NOUR_Constant &&
2988 (VD->getType()->isReferenceType() ||
2989 !canEmitSpuriousReferenceToVariable(*this, E, VD))) {
2990 VD->getAnyInitializer(VD);
2991 llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
2992 E->getLocation(), *VD->evaluateValue(), VD->getType());
2993 assert(Val && "failed to emit constant expression");
2994
2995 Address Addr = Address::invalid();
2996 if (!VD->getType()->isReferenceType()) {
2997 // Spill the constant value to a global.
2998 Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
2999 getContext().getDeclAlign(VD));
3000 llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
3001 auto *PTy = llvm::PointerType::get(
3002 VarTy, getTypes().getTargetAddressSpace(VD->getType()));
3003 Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy, VarTy);
3004 } else {
3005 // Should we be using the alignment of the constant pointer we emitted?
3006 CharUnits Alignment =
3007 CGM.getNaturalTypeAlignment(E->getType(),
3008 /* BaseInfo= */ nullptr,
3009 /* TBAAInfo= */ nullptr,
3010 /* forPointeeType= */ true);
3011 Addr = Address(Val, ConvertTypeForMem(E->getType()), Alignment);
3012 }
3013 return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
3014 }
3015
3016 // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
3017
3018 // Check for captured variables.
3019 if (E->refersToEnclosingVariableOrCapture()) {
3020 VD = VD->getCanonicalDecl();
3021 if (auto *FD = LambdaCaptureFields.lookup(VD))
3022 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
3023 if (CapturedStmtInfo) {
3024 auto I = LocalDeclMap.find(VD);
3025 if (I != LocalDeclMap.end()) {
3026 LValue CapLVal;
3027 if (VD->getType()->isReferenceType())
3028 CapLVal = EmitLoadOfReferenceLValue(I->second, VD->getType(),
3029 AlignmentSource::Decl);
3030 else
3031 CapLVal = MakeAddrLValue(I->second, T);
3032 // Mark lvalue as nontemporal if the variable is marked as nontemporal
3033 // in simd context.
3034 if (getLangOpts().OpenMP &&
3035 CGM.getOpenMPRuntime().isNontemporalDecl(VD))
3036 CapLVal.setNontemporal(/*Value=*/true);
3037 return CapLVal;
3038 }
3039 LValue CapLVal =
3040 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD),
3041 CapturedStmtInfo->getContextValue());
3042 Address LValueAddress = CapLVal.getAddress(*this);
3043 CapLVal = MakeAddrLValue(
3044 Address(LValueAddress.getPointer(), LValueAddress.getElementType(),
3045 getContext().getDeclAlign(VD)),
3046 CapLVal.getType(), LValueBaseInfo(AlignmentSource::Decl),
3047 CapLVal.getTBAAInfo());
3048 // Mark lvalue as nontemporal if the variable is marked as nontemporal
3049 // in simd context.
3050 if (getLangOpts().OpenMP &&
3051 CGM.getOpenMPRuntime().isNontemporalDecl(VD))
3052 CapLVal.setNontemporal(/*Value=*/true);
3053 return CapLVal;
3054 }
3055
3056 assert(isa<BlockDecl>(CurCodeDecl));
3057 Address addr = GetAddrOfBlockDecl(VD);
3058 return MakeAddrLValue(addr, T, AlignmentSource::Decl);
3059 }
3060 }
3061
3062 // FIXME: We should be able to assert this for FunctionDecls as well!
3063 // FIXME: We should be able to assert this for all DeclRefExprs, not just
3064 // those with a valid source location.
3065 assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
3066 !E->getLocation().isValid()) &&
3067 "Should not use decl without marking it used!");
3068
3069 if (ND->hasAttr<WeakRefAttr>()) {
3070 const auto *VD = cast<ValueDecl>(ND);
3071 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
3072 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
3073 }
3074
3075 if (const auto *VD = dyn_cast<VarDecl>(ND)) {
3076 // Check if this is a global variable.
3077 if (VD->hasLinkage() || VD->isStaticDataMember())
3078 return EmitGlobalVarDeclLValue(*this, E, VD);
3079
3080 Address addr = Address::invalid();
3081
3082 // The variable should generally be present in the local decl map.
3083 auto iter = LocalDeclMap.find(VD);
3084 if (iter != LocalDeclMap.end()) {
3085 addr = iter->second;
3086
3087 // Otherwise, it might be static local we haven't emitted yet for
3088 // some reason; most likely, because it's in an outer function.
3089 } else if (VD->isStaticLocal()) {
3090 llvm::Constant *var = CGM.getOrCreateStaticVarDecl(
3091 *VD, CGM.getLLVMLinkageVarDefinition(VD));
3092 addr = Address(
3093 var, ConvertTypeForMem(VD->getType()), getContext().getDeclAlign(VD));
3094
3095 // No other cases for now.
3096 } else {
3097 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
3098 }
3099
3100 // Handle threadlocal function locals.
3101 if (VD->getTLSKind() != VarDecl::TLS_None)
3102 addr = addr.withPointer(
3103 Builder.CreateThreadLocalAddress(addr.getPointer()), NotKnownNonNull);
3104
3105 // Check for OpenMP threadprivate variables.
3106 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
3107 VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
3108 return EmitThreadPrivateVarDeclLValue(
3109 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
3110 E->getExprLoc());
3111 }
3112
3113 // Drill into block byref variables.
3114 bool isBlockByref = VD->isEscapingByref();
3115 if (isBlockByref) {
3116 addr = emitBlockByrefAddress(addr, VD);
3117 }
3118
3119 // Drill into reference types.
3120 LValue LV = VD->getType()->isReferenceType() ?
3121 EmitLoadOfReferenceLValue(addr, VD->getType(), AlignmentSource::Decl) :
3122 MakeAddrLValue(addr, T, AlignmentSource::Decl);
3123
3124 bool isLocalStorage = VD->hasLocalStorage();
3125
3126 bool NonGCable = isLocalStorage &&
3127 !VD->getType()->isReferenceType() &&
3128 !isBlockByref;
3129 if (NonGCable) {
3130 LV.getQuals().removeObjCGCAttr();
3131 LV.setNonGC(true);
3132 }
3133
3134 bool isImpreciseLifetime =
3135 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
3136 if (isImpreciseLifetime)
3137 LV.setARCPreciseLifetime(ARCImpreciseLifetime);
3138 setObjCGCLValueClass(getContext(), E, LV);
3139 return LV;
3140 }
3141
3142 if (const auto *FD = dyn_cast<FunctionDecl>(ND)) {
3143 LValue LV = EmitFunctionDeclLValue(*this, E, FD);
3144
3145 // Emit debuginfo for the function declaration if the target wants to.
3146 if (getContext().getTargetInfo().allowDebugInfoForExternalRef()) {
3147 if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) {
3148 auto *Fn =
3149 cast<llvm::Function>(LV.getPointer(*this)->stripPointerCasts());
3150 if (!Fn->getSubprogram())
3151 DI->EmitFunctionDecl(FD, FD->getLocation(), T, Fn);
3152 }
3153 }
3154
3155 return LV;
3156 }
3157
3158 // FIXME: While we're emitting a binding from an enclosing scope, all other
3159 // DeclRefExprs we see should be implicitly treated as if they also refer to
3160 // an enclosing scope.
3161 if (const auto *BD = dyn_cast<BindingDecl>(ND)) {
3162 if (E->refersToEnclosingVariableOrCapture()) {
3163 auto *FD = LambdaCaptureFields.lookup(BD);
3164 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
3165 }
3166 return EmitLValue(BD->getBinding());
3167 }
3168
3169 // We can form DeclRefExprs naming GUID declarations when reconstituting
3170 // non-type template parameters into expressions.
3171 if (const auto *GD = dyn_cast<MSGuidDecl>(ND))
3172 return MakeAddrLValue(CGM.GetAddrOfMSGuidDecl(GD), T,
3173 AlignmentSource::Decl);
3174
3175 if (const auto *TPO = dyn_cast<TemplateParamObjectDecl>(ND)) {
3176 auto ATPO = CGM.GetAddrOfTemplateParamObject(TPO);
3177 auto AS = getLangASFromTargetAS(ATPO.getAddressSpace());
3178
3179 if (AS != T.getAddressSpace()) {
3180 auto TargetAS = getContext().getTargetAddressSpace(T.getAddressSpace());
3181 auto PtrTy = ATPO.getElementType()->getPointerTo(TargetAS);
3182 auto ASC = getTargetHooks().performAddrSpaceCast(
3183 CGM, ATPO.getPointer(), AS, T.getAddressSpace(), PtrTy);
3184 ATPO = ConstantAddress(ASC, ATPO.getElementType(), ATPO.getAlignment());
3185 }
3186
3187 return MakeAddrLValue(ATPO, T, AlignmentSource::Decl);
3188 }
3189
3190 llvm_unreachable("Unhandled DeclRefExpr");
3191 }
3192
EmitUnaryOpLValue(const UnaryOperator * E)3193 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) {
3194 // __extension__ doesn't affect lvalue-ness.
3195 if (E->getOpcode() == UO_Extension)
3196 return EmitLValue(E->getSubExpr());
3197
3198 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType());
3199 switch (E->getOpcode()) {
3200 default: llvm_unreachable("Unknown unary operator lvalue!");
3201 case UO_Deref: {
3202 QualType T = E->getSubExpr()->getType()->getPointeeType();
3203 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
3204
3205 LValueBaseInfo BaseInfo;
3206 TBAAAccessInfo TBAAInfo;
3207 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
3208 &TBAAInfo);
3209 LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
3210 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
3211
3212 // We should not generate __weak write barrier on indirect reference
3213 // of a pointer to object; as in void foo (__weak id *param); *param = 0;
3214 // But, we continue to generate __strong write barrier on indirect write
3215 // into a pointer to object.
3216 if (getLangOpts().ObjC &&
3217 getLangOpts().getGC() != LangOptions::NonGC &&
3218 LV.isObjCWeak())
3219 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
3220 return LV;
3221 }
3222 case UO_Real:
3223 case UO_Imag: {
3224 LValue LV = EmitLValue(E->getSubExpr());
3225 assert(LV.isSimple() && "real/imag on non-ordinary l-value");
3226
3227 // __real is valid on scalars. This is a faster way of testing that.
3228 // __imag can only produce an rvalue on scalars.
3229 if (E->getOpcode() == UO_Real &&
3230 !LV.getAddress(*this).getElementType()->isStructTy()) {
3231 assert(E->getSubExpr()->getType()->isArithmeticType());
3232 return LV;
3233 }
3234
3235 QualType T = ExprTy->castAs<ComplexType>()->getElementType();
3236
3237 Address Component =
3238 (E->getOpcode() == UO_Real
3239 ? emitAddrOfRealComponent(LV.getAddress(*this), LV.getType())
3240 : emitAddrOfImagComponent(LV.getAddress(*this), LV.getType()));
3241 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
3242 CGM.getTBAAInfoForSubobject(LV, T));
3243 ElemLV.getQuals().addQualifiers(LV.getQuals());
3244 return ElemLV;
3245 }
3246 case UO_PreInc:
3247 case UO_PreDec: {
3248 LValue LV = EmitLValue(E->getSubExpr());
3249 bool isInc = E->getOpcode() == UO_PreInc;
3250
3251 if (E->getType()->isAnyComplexType())
3252 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
3253 else
3254 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
3255 return LV;
3256 }
3257 }
3258 }
3259
EmitStringLiteralLValue(const StringLiteral * E)3260 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) {
3261 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E),
3262 E->getType(), AlignmentSource::Decl);
3263 }
3264
EmitObjCEncodeExprLValue(const ObjCEncodeExpr * E)3265 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) {
3266 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E),
3267 E->getType(), AlignmentSource::Decl);
3268 }
3269
EmitPredefinedLValue(const PredefinedExpr * E)3270 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) {
3271 auto SL = E->getFunctionName();
3272 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
3273 StringRef FnName = CurFn->getName();
3274 if (FnName.starts_with("\01"))
3275 FnName = FnName.substr(1);
3276 StringRef NameItems[] = {
3277 PredefinedExpr::getIdentKindName(E->getIdentKind()), FnName};
3278 std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
3279 if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
3280 std::string Name = std::string(SL->getString());
3281 if (!Name.empty()) {
3282 unsigned Discriminator =
3283 CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
3284 if (Discriminator)
3285 Name += "_" + Twine(Discriminator + 1).str();
3286 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
3287 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
3288 } else {
3289 auto C =
3290 CGM.GetAddrOfConstantCString(std::string(FnName), GVName.c_str());
3291 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
3292 }
3293 }
3294 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
3295 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
3296 }
3297
3298 /// Emit a type description suitable for use by a runtime sanitizer library. The
3299 /// format of a type descriptor is
3300 ///
3301 /// \code
3302 /// { i16 TypeKind, i16 TypeInfo }
3303 /// \endcode
3304 ///
3305 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
3306 /// integer, 1 for a floating point value, and -1 for anything else.
EmitCheckTypeDescriptor(QualType T)3307 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) {
3308 // Only emit each type's descriptor once.
3309 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
3310 return C;
3311
3312 uint16_t TypeKind = -1;
3313 uint16_t TypeInfo = 0;
3314
3315 if (T->isIntegerType()) {
3316 TypeKind = 0;
3317 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
3318 (T->isSignedIntegerType() ? 1 : 0);
3319 } else if (T->isFloatingType()) {
3320 TypeKind = 1;
3321 TypeInfo = getContext().getTypeSize(T);
3322 }
3323
3324 // Format the type name as if for a diagnostic, including quotes and
3325 // optionally an 'aka'.
3326 SmallString<32> Buffer;
3327 CGM.getDiags().ConvertArgToString(
3328 DiagnosticsEngine::ak_qualtype, (intptr_t)T.getAsOpaquePtr(), StringRef(),
3329 StringRef(), std::nullopt, Buffer, std::nullopt);
3330
3331 llvm::Constant *Components[] = {
3332 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
3333 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
3334 };
3335 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
3336
3337 auto *GV = new llvm::GlobalVariable(
3338 CGM.getModule(), Descriptor->getType(),
3339 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
3340 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3341 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV);
3342
3343 // Remember the descriptor for this type.
3344 CGM.setTypeDescriptorInMap(T, GV);
3345
3346 return GV;
3347 }
3348
EmitCheckValue(llvm::Value * V)3349 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) {
3350 llvm::Type *TargetTy = IntPtrTy;
3351
3352 if (V->getType() == TargetTy)
3353 return V;
3354
3355 // Floating-point types which fit into intptr_t are bitcast to integers
3356 // and then passed directly (after zero-extension, if necessary).
3357 if (V->getType()->isFloatingPointTy()) {
3358 unsigned Bits = V->getType()->getPrimitiveSizeInBits().getFixedValue();
3359 if (Bits <= TargetTy->getIntegerBitWidth())
3360 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
3361 Bits));
3362 }
3363
3364 // Integers which fit in intptr_t are zero-extended and passed directly.
3365 if (V->getType()->isIntegerTy() &&
3366 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
3367 return Builder.CreateZExt(V, TargetTy);
3368
3369 // Pointers are passed directly, everything else is passed by address.
3370 if (!V->getType()->isPointerTy()) {
3371 Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
3372 Builder.CreateStore(V, Ptr);
3373 V = Ptr.getPointer();
3374 }
3375 return Builder.CreatePtrToInt(V, TargetTy);
3376 }
3377
3378 /// Emit a representation of a SourceLocation for passing to a handler
3379 /// in a sanitizer runtime library. The format for this data is:
3380 /// \code
3381 /// struct SourceLocation {
3382 /// const char *Filename;
3383 /// int32_t Line, Column;
3384 /// };
3385 /// \endcode
3386 /// For an invalid SourceLocation, the Filename pointer is null.
EmitCheckSourceLocation(SourceLocation Loc)3387 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) {
3388 llvm::Constant *Filename;
3389 int Line, Column;
3390
3391 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc);
3392 if (PLoc.isValid()) {
3393 StringRef FilenameString = PLoc.getFilename();
3394
3395 int PathComponentsToStrip =
3396 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
3397 if (PathComponentsToStrip < 0) {
3398 assert(PathComponentsToStrip != INT_MIN);
3399 int PathComponentsToKeep = -PathComponentsToStrip;
3400 auto I = llvm::sys::path::rbegin(FilenameString);
3401 auto E = llvm::sys::path::rend(FilenameString);
3402 while (I != E && --PathComponentsToKeep)
3403 ++I;
3404
3405 FilenameString = FilenameString.substr(I - E);
3406 } else if (PathComponentsToStrip > 0) {
3407 auto I = llvm::sys::path::begin(FilenameString);
3408 auto E = llvm::sys::path::end(FilenameString);
3409 while (I != E && PathComponentsToStrip--)
3410 ++I;
3411
3412 if (I != E)
3413 FilenameString =
3414 FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
3415 else
3416 FilenameString = llvm::sys::path::filename(FilenameString);
3417 }
3418
3419 auto FilenameGV =
3420 CGM.GetAddrOfConstantCString(std::string(FilenameString), ".src");
3421 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(
3422 cast<llvm::GlobalVariable>(
3423 FilenameGV.getPointer()->stripPointerCasts()));
3424 Filename = FilenameGV.getPointer();
3425 Line = PLoc.getLine();
3426 Column = PLoc.getColumn();
3427 } else {
3428 Filename = llvm::Constant::getNullValue(Int8PtrTy);
3429 Line = Column = 0;
3430 }
3431
3432 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
3433 Builder.getInt32(Column)};
3434
3435 return llvm::ConstantStruct::getAnon(Data);
3436 }
3437
3438 namespace {
3439 /// Specify under what conditions this check can be recovered
3440 enum class CheckRecoverableKind {
3441 /// Always terminate program execution if this check fails.
3442 Unrecoverable,
3443 /// Check supports recovering, runtime has both fatal (noreturn) and
3444 /// non-fatal handlers for this check.
3445 Recoverable,
3446 /// Runtime conditionally aborts, always need to support recovery.
3447 AlwaysRecoverable
3448 };
3449 }
3450
getRecoverableKind(SanitizerMask Kind)3451 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
3452 assert(Kind.countPopulation() == 1);
3453 if (Kind == SanitizerKind::Vptr)
3454 return CheckRecoverableKind::AlwaysRecoverable;
3455 else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
3456 return CheckRecoverableKind::Unrecoverable;
3457 else
3458 return CheckRecoverableKind::Recoverable;
3459 }
3460
3461 namespace {
3462 struct SanitizerHandlerInfo {
3463 char const *const Name;
3464 unsigned Version;
3465 };
3466 }
3467
3468 const SanitizerHandlerInfo SanitizerHandlers[] = {
3469 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
3470 LIST_SANITIZER_CHECKS
3471 #undef SANITIZER_CHECK
3472 };
3473
emitCheckHandlerCall(CodeGenFunction & CGF,llvm::FunctionType * FnType,ArrayRef<llvm::Value * > FnArgs,SanitizerHandler CheckHandler,CheckRecoverableKind RecoverKind,bool IsFatal,llvm::BasicBlock * ContBB)3474 static void emitCheckHandlerCall(CodeGenFunction &CGF,
3475 llvm::FunctionType *FnType,
3476 ArrayRef<llvm::Value *> FnArgs,
3477 SanitizerHandler CheckHandler,
3478 CheckRecoverableKind RecoverKind, bool IsFatal,
3479 llvm::BasicBlock *ContBB) {
3480 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
3481 std::optional<ApplyDebugLocation> DL;
3482 if (!CGF.Builder.getCurrentDebugLocation()) {
3483 // Ensure that the call has at least an artificial debug location.
3484 DL.emplace(CGF, SourceLocation());
3485 }
3486 bool NeedsAbortSuffix =
3487 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
3488 bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
3489 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
3490 const StringRef CheckName = CheckInfo.Name;
3491 std::string FnName = "__ubsan_handle_" + CheckName.str();
3492 if (CheckInfo.Version && !MinimalRuntime)
3493 FnName += "_v" + llvm::utostr(CheckInfo.Version);
3494 if (MinimalRuntime)
3495 FnName += "_minimal";
3496 if (NeedsAbortSuffix)
3497 FnName += "_abort";
3498 bool MayReturn =
3499 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
3500
3501 llvm::AttrBuilder B(CGF.getLLVMContext());
3502 if (!MayReturn) {
3503 B.addAttribute(llvm::Attribute::NoReturn)
3504 .addAttribute(llvm::Attribute::NoUnwind);
3505 }
3506 B.addUWTableAttr(llvm::UWTableKind::Default);
3507
3508 llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
3509 FnType, FnName,
3510 llvm::AttributeList::get(CGF.getLLVMContext(),
3511 llvm::AttributeList::FunctionIndex, B),
3512 /*Local=*/true);
3513 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
3514 if (!MayReturn) {
3515 HandlerCall->setDoesNotReturn();
3516 CGF.Builder.CreateUnreachable();
3517 } else {
3518 CGF.Builder.CreateBr(ContBB);
3519 }
3520 }
3521
EmitCheck(ArrayRef<std::pair<llvm::Value *,SanitizerMask>> Checked,SanitizerHandler CheckHandler,ArrayRef<llvm::Constant * > StaticArgs,ArrayRef<llvm::Value * > DynamicArgs)3522 void CodeGenFunction::EmitCheck(
3523 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3524 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3525 ArrayRef<llvm::Value *> DynamicArgs) {
3526 assert(IsSanitizerScope);
3527 assert(Checked.size() > 0);
3528 assert(CheckHandler >= 0 &&
3529 size_t(CheckHandler) < std::size(SanitizerHandlers));
3530 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3531
3532 llvm::Value *FatalCond = nullptr;
3533 llvm::Value *RecoverableCond = nullptr;
3534 llvm::Value *TrapCond = nullptr;
3535 for (int i = 0, n = Checked.size(); i < n; ++i) {
3536 llvm::Value *Check = Checked[i].first;
3537 // -fsanitize-trap= overrides -fsanitize-recover=.
3538 llvm::Value *&Cond =
3539 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3540 ? TrapCond
3541 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3542 ? RecoverableCond
3543 : FatalCond;
3544 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3545 }
3546
3547 if (TrapCond)
3548 EmitTrapCheck(TrapCond, CheckHandler);
3549 if (!FatalCond && !RecoverableCond)
3550 return;
3551
3552 llvm::Value *JointCond;
3553 if (FatalCond && RecoverableCond)
3554 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3555 else
3556 JointCond = FatalCond ? FatalCond : RecoverableCond;
3557 assert(JointCond);
3558
3559 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3560 assert(SanOpts.has(Checked[0].second));
3561 #ifndef NDEBUG
3562 for (int i = 1, n = Checked.size(); i < n; ++i) {
3563 assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3564 "All recoverable kinds in a single check must be same!");
3565 assert(SanOpts.has(Checked[i].second));
3566 }
3567 #endif
3568
3569 llvm::BasicBlock *Cont = createBasicBlock("cont");
3570 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3571 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3572 // Give hint that we very much don't expect to execute the handler
3573 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
3574 llvm::MDBuilder MDHelper(getLLVMContext());
3575 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3576 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3577 EmitBlock(Handlers);
3578
3579 // Handler functions take an i8* pointing to the (handler-specific) static
3580 // information block, followed by a sequence of intptr_t arguments
3581 // representing operand values.
3582 SmallVector<llvm::Value *, 4> Args;
3583 SmallVector<llvm::Type *, 4> ArgTypes;
3584 if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3585 Args.reserve(DynamicArgs.size() + 1);
3586 ArgTypes.reserve(DynamicArgs.size() + 1);
3587
3588 // Emit handler arguments and create handler function type.
3589 if (!StaticArgs.empty()) {
3590 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3591 auto *InfoPtr = new llvm::GlobalVariable(
3592 CGM.getModule(), Info->getType(), false,
3593 llvm::GlobalVariable::PrivateLinkage, Info, "", nullptr,
3594 llvm::GlobalVariable::NotThreadLocal,
3595 CGM.getDataLayout().getDefaultGlobalsAddressSpace());
3596 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3597 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3598 Args.push_back(InfoPtr);
3599 ArgTypes.push_back(Args.back()->getType());
3600 }
3601
3602 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3603 Args.push_back(EmitCheckValue(DynamicArgs[i]));
3604 ArgTypes.push_back(IntPtrTy);
3605 }
3606 }
3607
3608 llvm::FunctionType *FnType =
3609 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3610
3611 if (!FatalCond || !RecoverableCond) {
3612 // Simple case: we need to generate a single handler call, either
3613 // fatal, or non-fatal.
3614 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3615 (FatalCond != nullptr), Cont);
3616 } else {
3617 // Emit two handler calls: first one for set of unrecoverable checks,
3618 // another one for recoverable.
3619 llvm::BasicBlock *NonFatalHandlerBB =
3620 createBasicBlock("non_fatal." + CheckName);
3621 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3622 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3623 EmitBlock(FatalHandlerBB);
3624 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3625 NonFatalHandlerBB);
3626 EmitBlock(NonFatalHandlerBB);
3627 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3628 Cont);
3629 }
3630
3631 EmitBlock(Cont);
3632 }
3633
EmitCfiSlowPathCheck(SanitizerMask Kind,llvm::Value * Cond,llvm::ConstantInt * TypeId,llvm::Value * Ptr,ArrayRef<llvm::Constant * > StaticArgs)3634 void CodeGenFunction::EmitCfiSlowPathCheck(
3635 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3636 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3637 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3638
3639 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3640 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3641
3642 llvm::MDBuilder MDHelper(getLLVMContext());
3643 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3644 BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3645
3646 EmitBlock(CheckBB);
3647
3648 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3649
3650 llvm::CallInst *CheckCall;
3651 llvm::FunctionCallee SlowPathFn;
3652 if (WithDiag) {
3653 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3654 auto *InfoPtr =
3655 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3656 llvm::GlobalVariable::PrivateLinkage, Info);
3657 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3658 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr);
3659
3660 SlowPathFn = CGM.getModule().getOrInsertFunction(
3661 "__cfi_slowpath_diag",
3662 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3663 false));
3664 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr, InfoPtr});
3665 } else {
3666 SlowPathFn = CGM.getModule().getOrInsertFunction(
3667 "__cfi_slowpath",
3668 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3669 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3670 }
3671
3672 CGM.setDSOLocal(
3673 cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3674 CheckCall->setDoesNotThrow();
3675
3676 EmitBlock(Cont);
3677 }
3678
3679 // Emit a stub for __cfi_check function so that the linker knows about this
3680 // symbol in LTO mode.
EmitCfiCheckStub()3681 void CodeGenFunction::EmitCfiCheckStub() {
3682 llvm::Module *M = &CGM.getModule();
3683 auto &Ctx = M->getContext();
3684 llvm::Function *F = llvm::Function::Create(
3685 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3686 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3687 F->setAlignment(llvm::Align(4096));
3688 CGM.setDSOLocal(F);
3689 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3690 // CrossDSOCFI pass is not executed if there is no executable code.
3691 SmallVector<llvm::Value*> Args{F->getArg(2), F->getArg(1)};
3692 llvm::CallInst::Create(M->getFunction("__cfi_check_fail"), Args, "", BB);
3693 llvm::ReturnInst::Create(Ctx, nullptr, BB);
3694 }
3695
3696 // This function is basically a switch over the CFI failure kind, which is
3697 // extracted from CFICheckFailData (1st function argument). Each case is either
3698 // llvm.trap or a call to one of the two runtime handlers, based on
3699 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3700 // failure kind) traps, but this should really never happen. CFICheckFailData
3701 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3702 // check kind; in this case __cfi_check_fail traps as well.
EmitCfiCheckFail()3703 void CodeGenFunction::EmitCfiCheckFail() {
3704 SanitizerScope SanScope(this);
3705 FunctionArgList Args;
3706 ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy,
3707 ImplicitParamKind::Other);
3708 ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy,
3709 ImplicitParamKind::Other);
3710 Args.push_back(&ArgData);
3711 Args.push_back(&ArgAddr);
3712
3713 const CGFunctionInfo &FI =
3714 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args);
3715
3716 llvm::Function *F = llvm::Function::Create(
3717 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3718 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3719
3720 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F, /*IsThunk=*/false);
3721 CGM.SetLLVMFunctionAttributesForDefinition(nullptr, F);
3722 F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3723
3724 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3725 SourceLocation());
3726
3727 // This function is not affected by NoSanitizeList. This function does
3728 // not have a source location, but "src:*" would still apply. Revert any
3729 // changes to SanOpts made in StartFunction.
3730 SanOpts = CGM.getLangOpts().Sanitize;
3731
3732 llvm::Value *Data =
3733 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3734 CGM.getContext().VoidPtrTy, ArgData.getLocation());
3735 llvm::Value *Addr =
3736 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3737 CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3738
3739 // Data == nullptr means the calling module has trap behaviour for this check.
3740 llvm::Value *DataIsNotNullPtr =
3741 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3742 EmitTrapCheck(DataIsNotNullPtr, SanitizerHandler::CFICheckFail);
3743
3744 llvm::StructType *SourceLocationTy =
3745 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3746 llvm::StructType *CfiCheckFailDataTy =
3747 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3748
3749 llvm::Value *V = Builder.CreateConstGEP2_32(
3750 CfiCheckFailDataTy,
3751 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3752 0);
3753
3754 Address CheckKindAddr(V, Int8Ty, getIntAlign());
3755 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3756
3757 llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3758 CGM.getLLVMContext(),
3759 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3760 llvm::Value *ValidVtable = Builder.CreateZExt(
3761 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3762 {Addr, AllVtables}),
3763 IntPtrTy);
3764
3765 const std::pair<int, SanitizerMask> CheckKinds[] = {
3766 {CFITCK_VCall, SanitizerKind::CFIVCall},
3767 {CFITCK_NVCall, SanitizerKind::CFINVCall},
3768 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3769 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3770 {CFITCK_ICall, SanitizerKind::CFIICall}};
3771
3772 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks;
3773 for (auto CheckKindMaskPair : CheckKinds) {
3774 int Kind = CheckKindMaskPair.first;
3775 SanitizerMask Mask = CheckKindMaskPair.second;
3776 llvm::Value *Cond =
3777 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3778 if (CGM.getLangOpts().Sanitize.has(Mask))
3779 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3780 {Data, Addr, ValidVtable});
3781 else
3782 EmitTrapCheck(Cond, SanitizerHandler::CFICheckFail);
3783 }
3784
3785 FinishFunction();
3786 // The only reference to this function will be created during LTO link.
3787 // Make sure it survives until then.
3788 CGM.addUsedGlobal(F);
3789 }
3790
EmitUnreachable(SourceLocation Loc)3791 void CodeGenFunction::EmitUnreachable(SourceLocation Loc) {
3792 if (SanOpts.has(SanitizerKind::Unreachable)) {
3793 SanitizerScope SanScope(this);
3794 EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3795 SanitizerKind::Unreachable),
3796 SanitizerHandler::BuiltinUnreachable,
3797 EmitCheckSourceLocation(Loc), std::nullopt);
3798 }
3799 Builder.CreateUnreachable();
3800 }
3801
EmitTrapCheck(llvm::Value * Checked,SanitizerHandler CheckHandlerID)3802 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked,
3803 SanitizerHandler CheckHandlerID) {
3804 llvm::BasicBlock *Cont = createBasicBlock("cont");
3805
3806 // If we're optimizing, collapse all calls to trap down to just one per
3807 // check-type per function to save on code size.
3808 if (TrapBBs.size() <= CheckHandlerID)
3809 TrapBBs.resize(CheckHandlerID + 1);
3810
3811 llvm::BasicBlock *&TrapBB = TrapBBs[CheckHandlerID];
3812
3813 if (!ClSanitizeDebugDeoptimization &&
3814 CGM.getCodeGenOpts().OptimizationLevel && TrapBB &&
3815 (!CurCodeDecl || !CurCodeDecl->hasAttr<OptimizeNoneAttr>())) {
3816 auto Call = TrapBB->begin();
3817 assert(isa<llvm::CallInst>(Call) && "Expected call in trap BB");
3818
3819 Call->applyMergedLocation(Call->getDebugLoc(),
3820 Builder.getCurrentDebugLocation());
3821 Builder.CreateCondBr(Checked, Cont, TrapBB);
3822 } else {
3823 TrapBB = createBasicBlock("trap");
3824 Builder.CreateCondBr(Checked, Cont, TrapBB);
3825 EmitBlock(TrapBB);
3826
3827 llvm::CallInst *TrapCall = Builder.CreateCall(
3828 CGM.getIntrinsic(llvm::Intrinsic::ubsantrap),
3829 llvm::ConstantInt::get(CGM.Int8Ty, ClSanitizeDebugDeoptimization
3830 ? TrapBB->getParent()->size()
3831 : CheckHandlerID));
3832
3833 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3834 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3835 CGM.getCodeGenOpts().TrapFuncName);
3836 TrapCall->addFnAttr(A);
3837 }
3838 TrapCall->setDoesNotReturn();
3839 TrapCall->setDoesNotThrow();
3840 Builder.CreateUnreachable();
3841 }
3842
3843 EmitBlock(Cont);
3844 }
3845
EmitTrapCall(llvm::Intrinsic::ID IntrID)3846 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) {
3847 llvm::CallInst *TrapCall =
3848 Builder.CreateCall(CGM.getIntrinsic(IntrID));
3849
3850 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3851 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3852 CGM.getCodeGenOpts().TrapFuncName);
3853 TrapCall->addFnAttr(A);
3854 }
3855
3856 return TrapCall;
3857 }
3858
EmitArrayToPointerDecay(const Expr * E,LValueBaseInfo * BaseInfo,TBAAAccessInfo * TBAAInfo)3859 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E,
3860 LValueBaseInfo *BaseInfo,
3861 TBAAAccessInfo *TBAAInfo) {
3862 assert(E->getType()->isArrayType() &&
3863 "Array to pointer decay must have array source type!");
3864
3865 // Expressions of array type can't be bitfields or vector elements.
3866 LValue LV = EmitLValue(E);
3867 Address Addr = LV.getAddress(*this);
3868
3869 // If the array type was an incomplete type, we need to make sure
3870 // the decay ends up being the right type.
3871 llvm::Type *NewTy = ConvertType(E->getType());
3872 Addr = Addr.withElementType(NewTy);
3873
3874 // Note that VLA pointers are always decayed, so we don't need to do
3875 // anything here.
3876 if (!E->getType()->isVariableArrayType()) {
3877 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3878 "Expected pointer to array");
3879 Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3880 }
3881
3882 // The result of this decay conversion points to an array element within the
3883 // base lvalue. However, since TBAA currently does not support representing
3884 // accesses to elements of member arrays, we conservatively represent accesses
3885 // to the pointee object as if it had no any base lvalue specified.
3886 // TODO: Support TBAA for member arrays.
3887 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType();
3888 if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3889 if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3890
3891 return Addr.withElementType(ConvertTypeForMem(EltType));
3892 }
3893
3894 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3895 /// array to pointer, return the array subexpression.
isSimpleArrayDecayOperand(const Expr * E)3896 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3897 // If this isn't just an array->pointer decay, bail out.
3898 const auto *CE = dyn_cast<CastExpr>(E);
3899 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3900 return nullptr;
3901
3902 // If this is a decay from variable width array, bail out.
3903 const Expr *SubExpr = CE->getSubExpr();
3904 if (SubExpr->getType()->isVariableArrayType())
3905 return nullptr;
3906
3907 return SubExpr;
3908 }
3909
emitArraySubscriptGEP(CodeGenFunction & CGF,llvm::Type * elemType,llvm::Value * ptr,ArrayRef<llvm::Value * > indices,bool inbounds,bool signedIndices,SourceLocation loc,const llvm::Twine & name="arrayidx")3910 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF,
3911 llvm::Type *elemType,
3912 llvm::Value *ptr,
3913 ArrayRef<llvm::Value*> indices,
3914 bool inbounds,
3915 bool signedIndices,
3916 SourceLocation loc,
3917 const llvm::Twine &name = "arrayidx") {
3918 if (inbounds) {
3919 return CGF.EmitCheckedInBoundsGEP(elemType, ptr, indices, signedIndices,
3920 CodeGenFunction::NotSubtraction, loc,
3921 name);
3922 } else {
3923 return CGF.Builder.CreateGEP(elemType, ptr, indices, name);
3924 }
3925 }
3926
getArrayElementAlign(CharUnits arrayAlign,llvm::Value * idx,CharUnits eltSize)3927 static CharUnits getArrayElementAlign(CharUnits arrayAlign,
3928 llvm::Value *idx,
3929 CharUnits eltSize) {
3930 // If we have a constant index, we can use the exact offset of the
3931 // element we're accessing.
3932 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3933 CharUnits offset = constantIdx->getZExtValue() * eltSize;
3934 return arrayAlign.alignmentAtOffset(offset);
3935
3936 // Otherwise, use the worst-case alignment for any element.
3937 } else {
3938 return arrayAlign.alignmentOfArrayElement(eltSize);
3939 }
3940 }
3941
getFixedSizeElementType(const ASTContext & ctx,const VariableArrayType * vla)3942 static QualType getFixedSizeElementType(const ASTContext &ctx,
3943 const VariableArrayType *vla) {
3944 QualType eltType;
3945 do {
3946 eltType = vla->getElementType();
3947 } while ((vla = ctx.getAsVariableArrayType(eltType)));
3948 return eltType;
3949 }
3950
hasBPFPreserveStaticOffset(const RecordDecl * D)3951 static bool hasBPFPreserveStaticOffset(const RecordDecl *D) {
3952 return D && D->hasAttr<BPFPreserveStaticOffsetAttr>();
3953 }
3954
hasBPFPreserveStaticOffset(const Expr * E)3955 static bool hasBPFPreserveStaticOffset(const Expr *E) {
3956 if (!E)
3957 return false;
3958 QualType PointeeType = E->getType()->getPointeeType();
3959 if (PointeeType.isNull())
3960 return false;
3961 if (const auto *BaseDecl = PointeeType->getAsRecordDecl())
3962 return hasBPFPreserveStaticOffset(BaseDecl);
3963 return false;
3964 }
3965
3966 // Wraps Addr with a call to llvm.preserve.static.offset intrinsic.
wrapWithBPFPreserveStaticOffset(CodeGenFunction & CGF,Address & Addr)3967 static Address wrapWithBPFPreserveStaticOffset(CodeGenFunction &CGF,
3968 Address &Addr) {
3969 if (!CGF.getTarget().getTriple().isBPF())
3970 return Addr;
3971
3972 llvm::Function *Fn =
3973 CGF.CGM.getIntrinsic(llvm::Intrinsic::preserve_static_offset);
3974 llvm::CallInst *Call = CGF.Builder.CreateCall(Fn, {Addr.getPointer()});
3975 return Address(Call, Addr.getElementType(), Addr.getAlignment());
3976 }
3977
3978 /// Given an array base, check whether its member access belongs to a record
3979 /// with preserve_access_index attribute or not.
IsPreserveAIArrayBase(CodeGenFunction & CGF,const Expr * ArrayBase)3980 static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) {
3981 if (!ArrayBase || !CGF.getDebugInfo())
3982 return false;
3983
3984 // Only support base as either a MemberExpr or DeclRefExpr.
3985 // DeclRefExpr to cover cases like:
3986 // struct s { int a; int b[10]; };
3987 // struct s *p;
3988 // p[1].a
3989 // p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr.
3990 // p->b[5] is a MemberExpr example.
3991 const Expr *E = ArrayBase->IgnoreImpCasts();
3992 if (const auto *ME = dyn_cast<MemberExpr>(E))
3993 return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
3994
3995 if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
3996 const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl());
3997 if (!VarDef)
3998 return false;
3999
4000 const auto *PtrT = VarDef->getType()->getAs<PointerType>();
4001 if (!PtrT)
4002 return false;
4003
4004 const auto *PointeeT = PtrT->getPointeeType()
4005 ->getUnqualifiedDesugaredType();
4006 if (const auto *RecT = dyn_cast<RecordType>(PointeeT))
4007 return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
4008 return false;
4009 }
4010
4011 return false;
4012 }
4013
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")4014 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr,
4015 ArrayRef<llvm::Value *> indices,
4016 QualType eltType, bool inbounds,
4017 bool signedIndices, SourceLocation loc,
4018 QualType *arrayType = nullptr,
4019 const Expr *Base = nullptr,
4020 const llvm::Twine &name = "arrayidx") {
4021 // All the indices except that last must be zero.
4022 #ifndef NDEBUG
4023 for (auto *idx : indices.drop_back())
4024 assert(isa<llvm::ConstantInt>(idx) &&
4025 cast<llvm::ConstantInt>(idx)->isZero());
4026 #endif
4027
4028 // Determine the element size of the statically-sized base. This is
4029 // the thing that the indices are expressed in terms of.
4030 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
4031 eltType = getFixedSizeElementType(CGF.getContext(), vla);
4032 }
4033
4034 // We can use that to compute the best alignment of the element.
4035 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
4036 CharUnits eltAlign =
4037 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
4038
4039 if (hasBPFPreserveStaticOffset(Base))
4040 addr = wrapWithBPFPreserveStaticOffset(CGF, addr);
4041
4042 llvm::Value *eltPtr;
4043 auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
4044 if (!LastIndex ||
4045 (!CGF.IsInPreservedAIRegion && !IsPreserveAIArrayBase(CGF, Base))) {
4046 eltPtr = emitArraySubscriptGEP(
4047 CGF, addr.getElementType(), addr.getPointer(), indices, inbounds,
4048 signedIndices, loc, name);
4049 } else {
4050 // Remember the original array subscript for bpf target
4051 unsigned idx = LastIndex->getZExtValue();
4052 llvm::DIType *DbgInfo = nullptr;
4053 if (arrayType)
4054 DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc);
4055 eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getElementType(),
4056 addr.getPointer(),
4057 indices.size() - 1,
4058 idx, DbgInfo);
4059 }
4060
4061 return Address(eltPtr, CGF.ConvertTypeForMem(eltType), eltAlign);
4062 }
4063
4064 /// The offset of a field from the beginning of the record.
getFieldOffsetInBits(CodeGenFunction & CGF,const RecordDecl * RD,const FieldDecl * FD,int64_t & Offset)4065 static bool getFieldOffsetInBits(CodeGenFunction &CGF, const RecordDecl *RD,
4066 const FieldDecl *FD, int64_t &Offset) {
4067 ASTContext &Ctx = CGF.getContext();
4068 const ASTRecordLayout &Layout = Ctx.getASTRecordLayout(RD);
4069 unsigned FieldNo = 0;
4070
4071 for (const Decl *D : RD->decls()) {
4072 if (const auto *Record = dyn_cast<RecordDecl>(D))
4073 if (getFieldOffsetInBits(CGF, Record, FD, Offset)) {
4074 Offset += Layout.getFieldOffset(FieldNo);
4075 return true;
4076 }
4077
4078 if (const auto *Field = dyn_cast<FieldDecl>(D))
4079 if (FD == Field) {
4080 Offset += Layout.getFieldOffset(FieldNo);
4081 return true;
4082 }
4083
4084 if (isa<FieldDecl>(D))
4085 ++FieldNo;
4086 }
4087
4088 return false;
4089 }
4090
4091 /// Returns the relative offset difference between \p FD1 and \p FD2.
4092 /// \code
4093 /// offsetof(struct foo, FD1) - offsetof(struct foo, FD2)
4094 /// \endcode
4095 /// Both fields must be within the same struct.
getOffsetDifferenceInBits(CodeGenFunction & CGF,const FieldDecl * FD1,const FieldDecl * FD2)4096 static std::optional<int64_t> getOffsetDifferenceInBits(CodeGenFunction &CGF,
4097 const FieldDecl *FD1,
4098 const FieldDecl *FD2) {
4099 const RecordDecl *FD1OuterRec =
4100 FD1->getParent()->getOuterLexicalRecordContext();
4101 const RecordDecl *FD2OuterRec =
4102 FD2->getParent()->getOuterLexicalRecordContext();
4103
4104 if (FD1OuterRec != FD2OuterRec)
4105 // Fields must be within the same RecordDecl.
4106 return std::optional<int64_t>();
4107
4108 int64_t FD1Offset = 0;
4109 if (!getFieldOffsetInBits(CGF, FD1OuterRec, FD1, FD1Offset))
4110 return std::optional<int64_t>();
4111
4112 int64_t FD2Offset = 0;
4113 if (!getFieldOffsetInBits(CGF, FD2OuterRec, FD2, FD2Offset))
4114 return std::optional<int64_t>();
4115
4116 return std::make_optional<int64_t>(FD1Offset - FD2Offset);
4117 }
4118
EmitArraySubscriptExpr(const ArraySubscriptExpr * E,bool Accessed)4119 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E,
4120 bool Accessed) {
4121 // The index must always be an integer, which is not an aggregate. Emit it
4122 // in lexical order (this complexity is, sadly, required by C++17).
4123 llvm::Value *IdxPre =
4124 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
4125 bool SignedIndices = false;
4126 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
4127 auto *Idx = IdxPre;
4128 if (E->getLHS() != E->getIdx()) {
4129 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
4130 Idx = EmitScalarExpr(E->getIdx());
4131 }
4132
4133 QualType IdxTy = E->getIdx()->getType();
4134 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
4135 SignedIndices |= IdxSigned;
4136
4137 if (SanOpts.has(SanitizerKind::ArrayBounds))
4138 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
4139
4140 // Extend or truncate the index type to 32 or 64-bits.
4141 if (Promote && Idx->getType() != IntPtrTy)
4142 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
4143
4144 return Idx;
4145 };
4146 IdxPre = nullptr;
4147
4148 // If the base is a vector type, then we are forming a vector element lvalue
4149 // with this subscript.
4150 if (E->getBase()->getType()->isVectorType() &&
4151 !isa<ExtVectorElementExpr>(E->getBase())) {
4152 // Emit the vector as an lvalue to get its address.
4153 LValue LHS = EmitLValue(E->getBase());
4154 auto *Idx = EmitIdxAfterBase(/*Promote*/false);
4155 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
4156 return LValue::MakeVectorElt(LHS.getAddress(*this), Idx,
4157 E->getBase()->getType(), LHS.getBaseInfo(),
4158 TBAAAccessInfo());
4159 }
4160
4161 // All the other cases basically behave like simple offsetting.
4162
4163 // Handle the extvector case we ignored above.
4164 if (isa<ExtVectorElementExpr>(E->getBase())) {
4165 LValue LV = EmitLValue(E->getBase());
4166 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4167 Address Addr = EmitExtVectorElementLValue(LV);
4168
4169 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
4170 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
4171 SignedIndices, E->getExprLoc());
4172 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
4173 CGM.getTBAAInfoForSubobject(LV, EltType));
4174 }
4175
4176 LValueBaseInfo EltBaseInfo;
4177 TBAAAccessInfo EltTBAAInfo;
4178 Address Addr = Address::invalid();
4179 if (const VariableArrayType *vla =
4180 getContext().getAsVariableArrayType(E->getType())) {
4181 // The base must be a pointer, which is not an aggregate. Emit
4182 // it. It needs to be emitted first in case it's what captures
4183 // the VLA bounds.
4184 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4185 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4186
4187 // The element count here is the total number of non-VLA elements.
4188 llvm::Value *numElements = getVLASize(vla).NumElts;
4189
4190 // Effectively, the multiply by the VLA size is part of the GEP.
4191 // GEP indexes are signed, and scaling an index isn't permitted to
4192 // signed-overflow, so we use the same semantics for our explicit
4193 // multiply. We suppress this if overflow is not undefined behavior.
4194 if (getLangOpts().isSignedOverflowDefined()) {
4195 Idx = Builder.CreateMul(Idx, numElements);
4196 } else {
4197 Idx = Builder.CreateNSWMul(Idx, numElements);
4198 }
4199
4200 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
4201 !getLangOpts().isSignedOverflowDefined(),
4202 SignedIndices, E->getExprLoc());
4203
4204 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
4205 // Indexing over an interface, as in "NSString *P; P[4];"
4206
4207 // Emit the base pointer.
4208 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4209 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4210
4211 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
4212 llvm::Value *InterfaceSizeVal =
4213 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
4214
4215 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
4216
4217 // We don't necessarily build correct LLVM struct types for ObjC
4218 // interfaces, so we can't rely on GEP to do this scaling
4219 // correctly, so we need to cast to i8*. FIXME: is this actually
4220 // true? A lot of other things in the fragile ABI would break...
4221 llvm::Type *OrigBaseElemTy = Addr.getElementType();
4222
4223 // Do the GEP.
4224 CharUnits EltAlign =
4225 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
4226 llvm::Value *EltPtr =
4227 emitArraySubscriptGEP(*this, Int8Ty, Addr.getPointer(), ScaledIdx,
4228 false, SignedIndices, E->getExprLoc());
4229 Addr = Address(EltPtr, OrigBaseElemTy, EltAlign);
4230 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
4231 // If this is A[i] where A is an array, the frontend will have decayed the
4232 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
4233 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
4234 // "gep x, i" here. Emit one "gep A, 0, i".
4235 assert(Array->getType()->isArrayType() &&
4236 "Array to pointer decay must have array source type!");
4237 LValue ArrayLV;
4238 // For simple multidimensional array indexing, set the 'accessed' flag for
4239 // better bounds-checking of the base expression.
4240 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
4241 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
4242 else
4243 ArrayLV = EmitLValue(Array);
4244 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4245
4246 if (SanOpts.has(SanitizerKind::ArrayBounds)) {
4247 // If the array being accessed has a "counted_by" attribute, generate
4248 // bounds checking code. The "count" field is at the top level of the
4249 // struct or in an anonymous struct, that's also at the top level. Future
4250 // expansions may allow the "count" to reside at any place in the struct,
4251 // but the value of "counted_by" will be a "simple" path to the count,
4252 // i.e. "a.b.count", so we shouldn't need the full force of EmitLValue or
4253 // similar to emit the correct GEP.
4254 const LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel =
4255 getLangOpts().getStrictFlexArraysLevel();
4256
4257 if (const auto *ME = dyn_cast<MemberExpr>(Array);
4258 ME &&
4259 ME->isFlexibleArrayMemberLike(getContext(), StrictFlexArraysLevel) &&
4260 ME->getMemberDecl()->hasAttr<CountedByAttr>()) {
4261 const FieldDecl *FAMDecl = dyn_cast<FieldDecl>(ME->getMemberDecl());
4262 if (const FieldDecl *CountFD = FindCountedByField(FAMDecl)) {
4263 if (std::optional<int64_t> Diff =
4264 getOffsetDifferenceInBits(*this, CountFD, FAMDecl)) {
4265 CharUnits OffsetDiff = CGM.getContext().toCharUnitsFromBits(*Diff);
4266
4267 // Create a GEP with a byte offset between the FAM and count and
4268 // use that to load the count value.
4269 Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(
4270 ArrayLV.getAddress(*this), Int8PtrTy, Int8Ty);
4271
4272 llvm::Type *CountTy = ConvertType(CountFD->getType());
4273 llvm::Value *Res = Builder.CreateInBoundsGEP(
4274 Int8Ty, Addr.getPointer(),
4275 Builder.getInt32(OffsetDiff.getQuantity()), ".counted_by.gep");
4276 Res = Builder.CreateAlignedLoad(CountTy, Res, getIntAlign(),
4277 ".counted_by.load");
4278
4279 // Now emit the bounds checking.
4280 EmitBoundsCheckImpl(E, Res, Idx, E->getIdx()->getType(),
4281 Array->getType(), Accessed);
4282 }
4283 }
4284 }
4285 }
4286
4287 // Propagate the alignment from the array itself to the result.
4288 QualType arrayType = Array->getType();
4289 Addr = emitArraySubscriptGEP(
4290 *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx},
4291 E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
4292 E->getExprLoc(), &arrayType, E->getBase());
4293 EltBaseInfo = ArrayLV.getBaseInfo();
4294 EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
4295 } else {
4296 // The base must be a pointer; emit it with an estimate of its alignment.
4297 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
4298 auto *Idx = EmitIdxAfterBase(/*Promote*/true);
4299 QualType ptrType = E->getBase()->getType();
4300 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
4301 !getLangOpts().isSignedOverflowDefined(),
4302 SignedIndices, E->getExprLoc(), &ptrType,
4303 E->getBase());
4304 }
4305
4306 LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
4307
4308 if (getLangOpts().ObjC &&
4309 getLangOpts().getGC() != LangOptions::NonGC) {
4310 LV.setNonGC(!E->isOBJCGCCandidate(getContext()));
4311 setObjCGCLValueClass(getContext(), E, LV);
4312 }
4313 return LV;
4314 }
4315
EmitMatrixSubscriptExpr(const MatrixSubscriptExpr * E)4316 LValue CodeGenFunction::EmitMatrixSubscriptExpr(const MatrixSubscriptExpr *E) {
4317 assert(
4318 !E->isIncomplete() &&
4319 "incomplete matrix subscript expressions should be rejected during Sema");
4320 LValue Base = EmitLValue(E->getBase());
4321 llvm::Value *RowIdx = EmitScalarExpr(E->getRowIdx());
4322 llvm::Value *ColIdx = EmitScalarExpr(E->getColumnIdx());
4323 llvm::Value *NumRows = Builder.getIntN(
4324 RowIdx->getType()->getScalarSizeInBits(),
4325 E->getBase()->getType()->castAs<ConstantMatrixType>()->getNumRows());
4326 llvm::Value *FinalIdx =
4327 Builder.CreateAdd(Builder.CreateMul(ColIdx, NumRows), RowIdx);
4328 return LValue::MakeMatrixElt(
4329 MaybeConvertMatrixAddress(Base.getAddress(*this), *this), FinalIdx,
4330 E->getBase()->getType(), Base.getBaseInfo(), TBAAAccessInfo());
4331 }
4332
emitOMPArraySectionBase(CodeGenFunction & CGF,const Expr * Base,LValueBaseInfo & BaseInfo,TBAAAccessInfo & TBAAInfo,QualType BaseTy,QualType ElTy,bool IsLowerBound)4333 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
4334 LValueBaseInfo &BaseInfo,
4335 TBAAAccessInfo &TBAAInfo,
4336 QualType BaseTy, QualType ElTy,
4337 bool IsLowerBound) {
4338 LValue BaseLVal;
4339 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
4340 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
4341 if (BaseTy->isArrayType()) {
4342 Address Addr = BaseLVal.getAddress(CGF);
4343 BaseInfo = BaseLVal.getBaseInfo();
4344
4345 // If the array type was an incomplete type, we need to make sure
4346 // the decay ends up being the right type.
4347 llvm::Type *NewTy = CGF.ConvertType(BaseTy);
4348 Addr = Addr.withElementType(NewTy);
4349
4350 // Note that VLA pointers are always decayed, so we don't need to do
4351 // anything here.
4352 if (!BaseTy->isVariableArrayType()) {
4353 assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
4354 "Expected pointer to array");
4355 Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
4356 }
4357
4358 return Addr.withElementType(CGF.ConvertTypeForMem(ElTy));
4359 }
4360 LValueBaseInfo TypeBaseInfo;
4361 TBAAAccessInfo TypeTBAAInfo;
4362 CharUnits Align =
4363 CGF.CGM.getNaturalTypeAlignment(ElTy, &TypeBaseInfo, &TypeTBAAInfo);
4364 BaseInfo.mergeForCast(TypeBaseInfo);
4365 TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
4366 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress(CGF)),
4367 CGF.ConvertTypeForMem(ElTy), Align);
4368 }
4369 return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
4370 }
4371
EmitOMPArraySectionExpr(const OMPArraySectionExpr * E,bool IsLowerBound)4372 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
4373 bool IsLowerBound) {
4374 QualType BaseTy = OMPArraySectionExpr::getBaseOriginalType(E->getBase());
4375 QualType ResultExprTy;
4376 if (auto *AT = getContext().getAsArrayType(BaseTy))
4377 ResultExprTy = AT->getElementType();
4378 else
4379 ResultExprTy = BaseTy->getPointeeType();
4380 llvm::Value *Idx = nullptr;
4381 if (IsLowerBound || E->getColonLocFirst().isInvalid()) {
4382 // Requesting lower bound or upper bound, but without provided length and
4383 // without ':' symbol for the default length -> length = 1.
4384 // Idx = LowerBound ?: 0;
4385 if (auto *LowerBound = E->getLowerBound()) {
4386 Idx = Builder.CreateIntCast(
4387 EmitScalarExpr(LowerBound), IntPtrTy,
4388 LowerBound->getType()->hasSignedIntegerRepresentation());
4389 } else
4390 Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
4391 } else {
4392 // Try to emit length or lower bound as constant. If this is possible, 1
4393 // is subtracted from constant length or lower bound. Otherwise, emit LLVM
4394 // IR (LB + Len) - 1.
4395 auto &C = CGM.getContext();
4396 auto *Length = E->getLength();
4397 llvm::APSInt ConstLength;
4398 if (Length) {
4399 // Idx = LowerBound + Length - 1;
4400 if (std::optional<llvm::APSInt> CL = Length->getIntegerConstantExpr(C)) {
4401 ConstLength = CL->zextOrTrunc(PointerWidthInBits);
4402 Length = nullptr;
4403 }
4404 auto *LowerBound = E->getLowerBound();
4405 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
4406 if (LowerBound) {
4407 if (std::optional<llvm::APSInt> LB =
4408 LowerBound->getIntegerConstantExpr(C)) {
4409 ConstLowerBound = LB->zextOrTrunc(PointerWidthInBits);
4410 LowerBound = nullptr;
4411 }
4412 }
4413 if (!Length)
4414 --ConstLength;
4415 else if (!LowerBound)
4416 --ConstLowerBound;
4417
4418 if (Length || LowerBound) {
4419 auto *LowerBoundVal =
4420 LowerBound
4421 ? Builder.CreateIntCast(
4422 EmitScalarExpr(LowerBound), IntPtrTy,
4423 LowerBound->getType()->hasSignedIntegerRepresentation())
4424 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
4425 auto *LengthVal =
4426 Length
4427 ? Builder.CreateIntCast(
4428 EmitScalarExpr(Length), IntPtrTy,
4429 Length->getType()->hasSignedIntegerRepresentation())
4430 : llvm::ConstantInt::get(IntPtrTy, ConstLength);
4431 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
4432 /*HasNUW=*/false,
4433 !getLangOpts().isSignedOverflowDefined());
4434 if (Length && LowerBound) {
4435 Idx = Builder.CreateSub(
4436 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
4437 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
4438 }
4439 } else
4440 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
4441 } else {
4442 // Idx = ArraySize - 1;
4443 QualType ArrayTy = BaseTy->isPointerType()
4444 ? E->getBase()->IgnoreParenImpCasts()->getType()
4445 : BaseTy;
4446 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
4447 Length = VAT->getSizeExpr();
4448 if (std::optional<llvm::APSInt> L = Length->getIntegerConstantExpr(C)) {
4449 ConstLength = *L;
4450 Length = nullptr;
4451 }
4452 } else {
4453 auto *CAT = C.getAsConstantArrayType(ArrayTy);
4454 assert(CAT && "unexpected type for array initializer");
4455 ConstLength = CAT->getSize();
4456 }
4457 if (Length) {
4458 auto *LengthVal = Builder.CreateIntCast(
4459 EmitScalarExpr(Length), IntPtrTy,
4460 Length->getType()->hasSignedIntegerRepresentation());
4461 Idx = Builder.CreateSub(
4462 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
4463 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
4464 } else {
4465 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
4466 --ConstLength;
4467 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
4468 }
4469 }
4470 }
4471 assert(Idx);
4472
4473 Address EltPtr = Address::invalid();
4474 LValueBaseInfo BaseInfo;
4475 TBAAAccessInfo TBAAInfo;
4476 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
4477 // The base must be a pointer, which is not an aggregate. Emit
4478 // it. It needs to be emitted first in case it's what captures
4479 // the VLA bounds.
4480 Address Base =
4481 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
4482 BaseTy, VLA->getElementType(), IsLowerBound);
4483 // The element count here is the total number of non-VLA elements.
4484 llvm::Value *NumElements = getVLASize(VLA).NumElts;
4485
4486 // Effectively, the multiply by the VLA size is part of the GEP.
4487 // GEP indexes are signed, and scaling an index isn't permitted to
4488 // signed-overflow, so we use the same semantics for our explicit
4489 // multiply. We suppress this if overflow is not undefined behavior.
4490 if (getLangOpts().isSignedOverflowDefined())
4491 Idx = Builder.CreateMul(Idx, NumElements);
4492 else
4493 Idx = Builder.CreateNSWMul(Idx, NumElements);
4494 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
4495 !getLangOpts().isSignedOverflowDefined(),
4496 /*signedIndices=*/false, E->getExprLoc());
4497 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
4498 // If this is A[i] where A is an array, the frontend will have decayed the
4499 // base to be a ArrayToPointerDecay implicit cast. While correct, it is
4500 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
4501 // "gep x, i" here. Emit one "gep A, 0, i".
4502 assert(Array->getType()->isArrayType() &&
4503 "Array to pointer decay must have array source type!");
4504 LValue ArrayLV;
4505 // For simple multidimensional array indexing, set the 'accessed' flag for
4506 // better bounds-checking of the base expression.
4507 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
4508 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
4509 else
4510 ArrayLV = EmitLValue(Array);
4511
4512 // Propagate the alignment from the array itself to the result.
4513 EltPtr = emitArraySubscriptGEP(
4514 *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx},
4515 ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
4516 /*signedIndices=*/false, E->getExprLoc());
4517 BaseInfo = ArrayLV.getBaseInfo();
4518 TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
4519 } else {
4520 Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
4521 TBAAInfo, BaseTy, ResultExprTy,
4522 IsLowerBound);
4523 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
4524 !getLangOpts().isSignedOverflowDefined(),
4525 /*signedIndices=*/false, E->getExprLoc());
4526 }
4527
4528 return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
4529 }
4530
4531 LValue CodeGenFunction::
EmitExtVectorElementExpr(const ExtVectorElementExpr * E)4532 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) {
4533 // Emit the base vector as an l-value.
4534 LValue Base;
4535
4536 // ExtVectorElementExpr's base can either be a vector or pointer to vector.
4537 if (E->isArrow()) {
4538 // If it is a pointer to a vector, emit the address and form an lvalue with
4539 // it.
4540 LValueBaseInfo BaseInfo;
4541 TBAAAccessInfo TBAAInfo;
4542 Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
4543 const auto *PT = E->getBase()->getType()->castAs<PointerType>();
4544 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
4545 Base.getQuals().removeObjCGCAttr();
4546 } else if (E->getBase()->isGLValue()) {
4547 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
4548 // emit the base as an lvalue.
4549 assert(E->getBase()->getType()->isVectorType());
4550 Base = EmitLValue(E->getBase());
4551 } else {
4552 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
4553 assert(E->getBase()->getType()->isVectorType() &&
4554 "Result must be a vector");
4555 llvm::Value *Vec = EmitScalarExpr(E->getBase());
4556
4557 // Store the vector to memory (because LValue wants an address).
4558 Address VecMem = CreateMemTemp(E->getBase()->getType());
4559 Builder.CreateStore(Vec, VecMem);
4560 Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
4561 AlignmentSource::Decl);
4562 }
4563
4564 QualType type =
4565 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
4566
4567 // Encode the element access list into a vector of unsigned indices.
4568 SmallVector<uint32_t, 4> Indices;
4569 E->getEncodedElementAccess(Indices);
4570
4571 if (Base.isSimple()) {
4572 llvm::Constant *CV =
4573 llvm::ConstantDataVector::get(getLLVMContext(), Indices);
4574 return LValue::MakeExtVectorElt(Base.getAddress(*this), CV, type,
4575 Base.getBaseInfo(), TBAAAccessInfo());
4576 }
4577 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
4578
4579 llvm::Constant *BaseElts = Base.getExtVectorElts();
4580 SmallVector<llvm::Constant *, 4> CElts;
4581
4582 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
4583 CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
4584 llvm::Constant *CV = llvm::ConstantVector::get(CElts);
4585 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
4586 Base.getBaseInfo(), TBAAAccessInfo());
4587 }
4588
EmitMemberExpr(const MemberExpr * E)4589 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) {
4590 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
4591 EmitIgnoredExpr(E->getBase());
4592 return EmitDeclRefLValue(DRE);
4593 }
4594
4595 Expr *BaseExpr = E->getBase();
4596 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
4597 LValue BaseLV;
4598 if (E->isArrow()) {
4599 LValueBaseInfo BaseInfo;
4600 TBAAAccessInfo TBAAInfo;
4601 Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
4602 QualType PtrTy = BaseExpr->getType()->getPointeeType();
4603 SanitizerSet SkippedChecks;
4604 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
4605 if (IsBaseCXXThis)
4606 SkippedChecks.set(SanitizerKind::Alignment, true);
4607 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
4608 SkippedChecks.set(SanitizerKind::Null, true);
4609 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
4610 /*Alignment=*/CharUnits::Zero(), SkippedChecks);
4611 BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
4612 } else
4613 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
4614
4615 NamedDecl *ND = E->getMemberDecl();
4616 if (auto *Field = dyn_cast<FieldDecl>(ND)) {
4617 LValue LV = EmitLValueForField(BaseLV, Field);
4618 setObjCGCLValueClass(getContext(), E, LV);
4619 if (getLangOpts().OpenMP) {
4620 // If the member was explicitly marked as nontemporal, mark it as
4621 // nontemporal. If the base lvalue is marked as nontemporal, mark access
4622 // to children as nontemporal too.
4623 if ((IsWrappedCXXThis(BaseExpr) &&
4624 CGM.getOpenMPRuntime().isNontemporalDecl(Field)) ||
4625 BaseLV.isNontemporal())
4626 LV.setNontemporal(/*Value=*/true);
4627 }
4628 return LV;
4629 }
4630
4631 if (const auto *FD = dyn_cast<FunctionDecl>(ND))
4632 return EmitFunctionDeclLValue(*this, E, FD);
4633
4634 llvm_unreachable("Unhandled member declaration!");
4635 }
4636
4637 /// Given that we are currently emitting a lambda, emit an l-value for
4638 /// one of its members.
4639 ///
EmitLValueForLambdaField(const FieldDecl * Field,llvm::Value * ThisValue)4640 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field,
4641 llvm::Value *ThisValue) {
4642 bool HasExplicitObjectParameter = false;
4643 if (const auto *MD = dyn_cast_if_present<CXXMethodDecl>(CurCodeDecl)) {
4644 HasExplicitObjectParameter = MD->isExplicitObjectMemberFunction();
4645 assert(MD->getParent()->isLambda());
4646 assert(MD->getParent() == Field->getParent());
4647 }
4648 LValue LambdaLV;
4649 if (HasExplicitObjectParameter) {
4650 const VarDecl *D = cast<CXXMethodDecl>(CurCodeDecl)->getParamDecl(0);
4651 auto It = LocalDeclMap.find(D);
4652 assert(It != LocalDeclMap.end() && "explicit parameter not loaded?");
4653 Address AddrOfExplicitObject = It->getSecond();
4654 if (D->getType()->isReferenceType())
4655 LambdaLV = EmitLoadOfReferenceLValue(AddrOfExplicitObject, D->getType(),
4656 AlignmentSource::Decl);
4657 else
4658 LambdaLV = MakeNaturalAlignAddrLValue(AddrOfExplicitObject.getPointer(),
4659 D->getType().getNonReferenceType());
4660 } else {
4661 QualType LambdaTagType = getContext().getTagDeclType(Field->getParent());
4662 LambdaLV = MakeNaturalAlignAddrLValue(ThisValue, LambdaTagType);
4663 }
4664 return EmitLValueForField(LambdaLV, Field);
4665 }
4666
EmitLValueForLambdaField(const FieldDecl * Field)4667 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) {
4668 return EmitLValueForLambdaField(Field, CXXABIThisValue);
4669 }
4670
4671 /// Get the field index in the debug info. The debug info structure/union
4672 /// will ignore the unnamed bitfields.
getDebugInfoFIndex(const RecordDecl * Rec,unsigned FieldIndex)4673 unsigned CodeGenFunction::getDebugInfoFIndex(const RecordDecl *Rec,
4674 unsigned FieldIndex) {
4675 unsigned I = 0, Skipped = 0;
4676
4677 for (auto *F : Rec->getDefinition()->fields()) {
4678 if (I == FieldIndex)
4679 break;
4680 if (F->isUnnamedBitfield())
4681 Skipped++;
4682 I++;
4683 }
4684
4685 return FieldIndex - Skipped;
4686 }
4687
4688 /// Get the address of a zero-sized field within a record. The resulting
4689 /// address doesn't necessarily have the right type.
emitAddrOfZeroSizeField(CodeGenFunction & CGF,Address Base,const FieldDecl * Field)4690 static Address emitAddrOfZeroSizeField(CodeGenFunction &CGF, Address Base,
4691 const FieldDecl *Field) {
4692 CharUnits Offset = CGF.getContext().toCharUnitsFromBits(
4693 CGF.getContext().getFieldOffset(Field));
4694 if (Offset.isZero())
4695 return Base;
4696 Base = Base.withElementType(CGF.Int8Ty);
4697 return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset);
4698 }
4699
4700 /// Drill down to the storage of a field without walking into
4701 /// reference types.
4702 ///
4703 /// The resulting address doesn't necessarily have the right type.
emitAddrOfFieldStorage(CodeGenFunction & CGF,Address base,const FieldDecl * field)4704 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base,
4705 const FieldDecl *field) {
4706 if (field->isZeroSize(CGF.getContext()))
4707 return emitAddrOfZeroSizeField(CGF, base, field);
4708
4709 const RecordDecl *rec = field->getParent();
4710
4711 unsigned idx =
4712 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
4713
4714 return CGF.Builder.CreateStructGEP(base, idx, field->getName());
4715 }
4716
emitPreserveStructAccess(CodeGenFunction & CGF,LValue base,Address addr,const FieldDecl * field)4717 static Address emitPreserveStructAccess(CodeGenFunction &CGF, LValue base,
4718 Address addr, const FieldDecl *field) {
4719 const RecordDecl *rec = field->getParent();
4720 llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(
4721 base.getType(), rec->getLocation());
4722
4723 unsigned idx =
4724 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
4725
4726 return CGF.Builder.CreatePreserveStructAccessIndex(
4727 addr, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
4728 }
4729
hasAnyVptr(const QualType Type,const ASTContext & Context)4730 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
4731 const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
4732 if (!RD)
4733 return false;
4734
4735 if (RD->isDynamicClass())
4736 return true;
4737
4738 for (const auto &Base : RD->bases())
4739 if (hasAnyVptr(Base.getType(), Context))
4740 return true;
4741
4742 for (const FieldDecl *Field : RD->fields())
4743 if (hasAnyVptr(Field->getType(), Context))
4744 return true;
4745
4746 return false;
4747 }
4748
EmitLValueForField(LValue base,const FieldDecl * field)4749 LValue CodeGenFunction::EmitLValueForField(LValue base,
4750 const FieldDecl *field) {
4751 LValueBaseInfo BaseInfo = base.getBaseInfo();
4752
4753 if (field->isBitField()) {
4754 const CGRecordLayout &RL =
4755 CGM.getTypes().getCGRecordLayout(field->getParent());
4756 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
4757 const bool UseVolatile = isAAPCS(CGM.getTarget()) &&
4758 CGM.getCodeGenOpts().AAPCSBitfieldWidth &&
4759 Info.VolatileStorageSize != 0 &&
4760 field->getType()
4761 .withCVRQualifiers(base.getVRQualifiers())
4762 .isVolatileQualified();
4763 Address Addr = base.getAddress(*this);
4764 unsigned Idx = RL.getLLVMFieldNo(field);
4765 const RecordDecl *rec = field->getParent();
4766 if (hasBPFPreserveStaticOffset(rec))
4767 Addr = wrapWithBPFPreserveStaticOffset(*this, Addr);
4768 if (!UseVolatile) {
4769 if (!IsInPreservedAIRegion &&
4770 (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
4771 if (Idx != 0)
4772 // For structs, we GEP to the field that the record layout suggests.
4773 Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
4774 } else {
4775 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4776 getContext().getRecordType(rec), rec->getLocation());
4777 Addr = Builder.CreatePreserveStructAccessIndex(
4778 Addr, Idx, getDebugInfoFIndex(rec, field->getFieldIndex()),
4779 DbgInfo);
4780 }
4781 }
4782 const unsigned SS =
4783 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
4784 // Get the access type.
4785 llvm::Type *FieldIntTy = llvm::Type::getIntNTy(getLLVMContext(), SS);
4786 Addr = Addr.withElementType(FieldIntTy);
4787 if (UseVolatile) {
4788 const unsigned VolatileOffset = Info.VolatileStorageOffset.getQuantity();
4789 if (VolatileOffset)
4790 Addr = Builder.CreateConstInBoundsGEP(Addr, VolatileOffset);
4791 }
4792
4793 QualType fieldType =
4794 field->getType().withCVRQualifiers(base.getVRQualifiers());
4795 // TODO: Support TBAA for bit fields.
4796 LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
4797 return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
4798 TBAAAccessInfo());
4799 }
4800
4801 // Fields of may-alias structures are may-alias themselves.
4802 // FIXME: this should get propagated down through anonymous structs
4803 // and unions.
4804 QualType FieldType = field->getType();
4805 const RecordDecl *rec = field->getParent();
4806 AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
4807 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
4808 TBAAAccessInfo FieldTBAAInfo;
4809 if (base.getTBAAInfo().isMayAlias() ||
4810 rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
4811 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4812 } else if (rec->isUnion()) {
4813 // TODO: Support TBAA for unions.
4814 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4815 } else {
4816 // If no base type been assigned for the base access, then try to generate
4817 // one for this base lvalue.
4818 FieldTBAAInfo = base.getTBAAInfo();
4819 if (!FieldTBAAInfo.BaseType) {
4820 FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
4821 assert(!FieldTBAAInfo.Offset &&
4822 "Nonzero offset for an access with no base type!");
4823 }
4824
4825 // Adjust offset to be relative to the base type.
4826 const ASTRecordLayout &Layout =
4827 getContext().getASTRecordLayout(field->getParent());
4828 unsigned CharWidth = getContext().getCharWidth();
4829 if (FieldTBAAInfo.BaseType)
4830 FieldTBAAInfo.Offset +=
4831 Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
4832
4833 // Update the final access type and size.
4834 FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
4835 FieldTBAAInfo.Size =
4836 getContext().getTypeSizeInChars(FieldType).getQuantity();
4837 }
4838
4839 Address addr = base.getAddress(*this);
4840 if (hasBPFPreserveStaticOffset(rec))
4841 addr = wrapWithBPFPreserveStaticOffset(*this, addr);
4842 if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
4843 if (CGM.getCodeGenOpts().StrictVTablePointers &&
4844 ClassDef->isDynamicClass()) {
4845 // Getting to any field of dynamic object requires stripping dynamic
4846 // information provided by invariant.group. This is because accessing
4847 // fields may leak the real address of dynamic object, which could result
4848 // in miscompilation when leaked pointer would be compared.
4849 auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
4850 addr = Address(stripped, addr.getElementType(), addr.getAlignment());
4851 }
4852 }
4853
4854 unsigned RecordCVR = base.getVRQualifiers();
4855 if (rec->isUnion()) {
4856 // For unions, there is no pointer adjustment.
4857 if (CGM.getCodeGenOpts().StrictVTablePointers &&
4858 hasAnyVptr(FieldType, getContext()))
4859 // Because unions can easily skip invariant.barriers, we need to add
4860 // a barrier every time CXXRecord field with vptr is referenced.
4861 addr = Builder.CreateLaunderInvariantGroup(addr);
4862
4863 if (IsInPreservedAIRegion ||
4864 (getDebugInfo() && rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
4865 // Remember the original union field index
4866 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateStandaloneType(base.getType(),
4867 rec->getLocation());
4868 addr = Address(
4869 Builder.CreatePreserveUnionAccessIndex(
4870 addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
4871 addr.getElementType(), addr.getAlignment());
4872 }
4873
4874 if (FieldType->isReferenceType())
4875 addr = addr.withElementType(CGM.getTypes().ConvertTypeForMem(FieldType));
4876 } else {
4877 if (!IsInPreservedAIRegion &&
4878 (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>()))
4879 // For structs, we GEP to the field that the record layout suggests.
4880 addr = emitAddrOfFieldStorage(*this, addr, field);
4881 else
4882 // Remember the original struct field index
4883 addr = emitPreserveStructAccess(*this, base, addr, field);
4884 }
4885
4886 // If this is a reference field, load the reference right now.
4887 if (FieldType->isReferenceType()) {
4888 LValue RefLVal =
4889 MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4890 if (RecordCVR & Qualifiers::Volatile)
4891 RefLVal.getQuals().addVolatile();
4892 addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
4893
4894 // Qualifiers on the struct don't apply to the referencee.
4895 RecordCVR = 0;
4896 FieldType = FieldType->getPointeeType();
4897 }
4898
4899 // Make sure that the address is pointing to the right type. This is critical
4900 // for both unions and structs.
4901 addr = addr.withElementType(CGM.getTypes().ConvertTypeForMem(FieldType));
4902
4903 if (field->hasAttr<AnnotateAttr>())
4904 addr = EmitFieldAnnotations(field, addr);
4905
4906 LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4907 LV.getQuals().addCVRQualifiers(RecordCVR);
4908
4909 // __weak attribute on a field is ignored.
4910 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
4911 LV.getQuals().removeObjCGCAttr();
4912
4913 return LV;
4914 }
4915
4916 LValue
EmitLValueForFieldInitialization(LValue Base,const FieldDecl * Field)4917 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base,
4918 const FieldDecl *Field) {
4919 QualType FieldType = Field->getType();
4920
4921 if (!FieldType->isReferenceType())
4922 return EmitLValueForField(Base, Field);
4923
4924 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(*this), Field);
4925
4926 // Make sure that the address is pointing to the right type.
4927 llvm::Type *llvmType = ConvertTypeForMem(FieldType);
4928 V = V.withElementType(llvmType);
4929
4930 // TODO: Generate TBAA information that describes this access as a structure
4931 // member access and not just an access to an object of the field's type. This
4932 // should be similar to what we do in EmitLValueForField().
4933 LValueBaseInfo BaseInfo = Base.getBaseInfo();
4934 AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
4935 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
4936 return MakeAddrLValue(V, FieldType, FieldBaseInfo,
4937 CGM.getTBAAInfoForSubobject(Base, FieldType));
4938 }
4939
EmitCompoundLiteralLValue(const CompoundLiteralExpr * E)4940 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){
4941 if (E->isFileScope()) {
4942 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E);
4943 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
4944 }
4945 if (E->getType()->isVariablyModifiedType())
4946 // make sure to emit the VLA size.
4947 EmitVariablyModifiedType(E->getType());
4948
4949 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4950 const Expr *InitExpr = E->getInitializer();
4951 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4952
4953 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4954 /*Init*/ true);
4955
4956 // Block-scope compound literals are destroyed at the end of the enclosing
4957 // scope in C.
4958 if (!getLangOpts().CPlusPlus)
4959 if (QualType::DestructionKind DtorKind = E->getType().isDestructedType())
4960 pushLifetimeExtendedDestroy(getCleanupKind(DtorKind), DeclPtr,
4961 E->getType(), getDestroyer(DtorKind),
4962 DtorKind & EHCleanup);
4963
4964 return Result;
4965 }
4966
EmitInitListLValue(const InitListExpr * E)4967 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) {
4968 if (!E->isGLValue())
4969 // Initializing an aggregate temporary in C++11: T{...}.
4970 return EmitAggExprToLValue(E);
4971
4972 // An lvalue initializer list must be initializing a reference.
4973 assert(E->isTransparent() && "non-transparent glvalue init list");
4974 return EmitLValue(E->getInit(0));
4975 }
4976
4977 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4978 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4979 /// LValue is returned and the current block has been terminated.
EmitLValueOrThrowExpression(CodeGenFunction & CGF,const Expr * Operand)4980 static std::optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF,
4981 const Expr *Operand) {
4982 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4983 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4984 return std::nullopt;
4985 }
4986
4987 return CGF.EmitLValue(Operand);
4988 }
4989
4990 namespace {
4991 // Handle the case where the condition is a constant evaluatable simple integer,
4992 // which means we don't have to separately handle the true/false blocks.
HandleConditionalOperatorLValueSimpleCase(CodeGenFunction & CGF,const AbstractConditionalOperator * E)4993 std::optional<LValue> HandleConditionalOperatorLValueSimpleCase(
4994 CodeGenFunction &CGF, const AbstractConditionalOperator *E) {
4995 const Expr *condExpr = E->getCond();
4996 bool CondExprBool;
4997 if (CGF.ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4998 const Expr *Live = E->getTrueExpr(), *Dead = E->getFalseExpr();
4999 if (!CondExprBool)
5000 std::swap(Live, Dead);
5001
5002 if (!CGF.ContainsLabel(Dead)) {
5003 // If the true case is live, we need to track its region.
5004 if (CondExprBool)
5005 CGF.incrementProfileCounter(E);
5006 // If a throw expression we emit it and return an undefined lvalue
5007 // because it can't be used.
5008 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Live->IgnoreParens())) {
5009 CGF.EmitCXXThrowExpr(ThrowExpr);
5010 llvm::Type *ElemTy = CGF.ConvertType(Dead->getType());
5011 llvm::Type *Ty = CGF.UnqualPtrTy;
5012 return CGF.MakeAddrLValue(
5013 Address(llvm::UndefValue::get(Ty), ElemTy, CharUnits::One()),
5014 Dead->getType());
5015 }
5016 return CGF.EmitLValue(Live);
5017 }
5018 }
5019 return std::nullopt;
5020 }
5021 struct ConditionalInfo {
5022 llvm::BasicBlock *lhsBlock, *rhsBlock;
5023 std::optional<LValue> LHS, RHS;
5024 };
5025
5026 // Create and generate the 3 blocks for a conditional operator.
5027 // Leaves the 'current block' in the continuation basic block.
5028 template<typename FuncTy>
EmitConditionalBlocks(CodeGenFunction & CGF,const AbstractConditionalOperator * E,const FuncTy & BranchGenFunc)5029 ConditionalInfo EmitConditionalBlocks(CodeGenFunction &CGF,
5030 const AbstractConditionalOperator *E,
5031 const FuncTy &BranchGenFunc) {
5032 ConditionalInfo Info{CGF.createBasicBlock("cond.true"),
5033 CGF.createBasicBlock("cond.false"), std::nullopt,
5034 std::nullopt};
5035 llvm::BasicBlock *endBlock = CGF.createBasicBlock("cond.end");
5036
5037 CodeGenFunction::ConditionalEvaluation eval(CGF);
5038 CGF.EmitBranchOnBoolExpr(E->getCond(), Info.lhsBlock, Info.rhsBlock,
5039 CGF.getProfileCount(E));
5040
5041 // Any temporaries created here are conditional.
5042 CGF.EmitBlock(Info.lhsBlock);
5043 CGF.incrementProfileCounter(E);
5044 eval.begin(CGF);
5045 Info.LHS = BranchGenFunc(CGF, E->getTrueExpr());
5046 eval.end(CGF);
5047 Info.lhsBlock = CGF.Builder.GetInsertBlock();
5048
5049 if (Info.LHS)
5050 CGF.Builder.CreateBr(endBlock);
5051
5052 // Any temporaries created here are conditional.
5053 CGF.EmitBlock(Info.rhsBlock);
5054 eval.begin(CGF);
5055 Info.RHS = BranchGenFunc(CGF, E->getFalseExpr());
5056 eval.end(CGF);
5057 Info.rhsBlock = CGF.Builder.GetInsertBlock();
5058 CGF.EmitBlock(endBlock);
5059
5060 return Info;
5061 }
5062 } // namespace
5063
EmitIgnoredConditionalOperator(const AbstractConditionalOperator * E)5064 void CodeGenFunction::EmitIgnoredConditionalOperator(
5065 const AbstractConditionalOperator *E) {
5066 if (!E->isGLValue()) {
5067 // ?: here should be an aggregate.
5068 assert(hasAggregateEvaluationKind(E->getType()) &&
5069 "Unexpected conditional operator!");
5070 return (void)EmitAggExprToLValue(E);
5071 }
5072
5073 OpaqueValueMapping binding(*this, E);
5074 if (HandleConditionalOperatorLValueSimpleCase(*this, E))
5075 return;
5076
5077 EmitConditionalBlocks(*this, E, [](CodeGenFunction &CGF, const Expr *E) {
5078 CGF.EmitIgnoredExpr(E);
5079 return LValue{};
5080 });
5081 }
EmitConditionalOperatorLValue(const AbstractConditionalOperator * expr)5082 LValue CodeGenFunction::EmitConditionalOperatorLValue(
5083 const AbstractConditionalOperator *expr) {
5084 if (!expr->isGLValue()) {
5085 // ?: here should be an aggregate.
5086 assert(hasAggregateEvaluationKind(expr->getType()) &&
5087 "Unexpected conditional operator!");
5088 return EmitAggExprToLValue(expr);
5089 }
5090
5091 OpaqueValueMapping binding(*this, expr);
5092 if (std::optional<LValue> Res =
5093 HandleConditionalOperatorLValueSimpleCase(*this, expr))
5094 return *Res;
5095
5096 ConditionalInfo Info = EmitConditionalBlocks(
5097 *this, expr, [](CodeGenFunction &CGF, const Expr *E) {
5098 return EmitLValueOrThrowExpression(CGF, E);
5099 });
5100
5101 if ((Info.LHS && !Info.LHS->isSimple()) ||
5102 (Info.RHS && !Info.RHS->isSimple()))
5103 return EmitUnsupportedLValue(expr, "conditional operator");
5104
5105 if (Info.LHS && Info.RHS) {
5106 Address lhsAddr = Info.LHS->getAddress(*this);
5107 Address rhsAddr = Info.RHS->getAddress(*this);
5108 llvm::PHINode *phi = Builder.CreatePHI(lhsAddr.getType(), 2, "cond-lvalue");
5109 phi->addIncoming(lhsAddr.getPointer(), Info.lhsBlock);
5110 phi->addIncoming(rhsAddr.getPointer(), Info.rhsBlock);
5111 Address result(phi, lhsAddr.getElementType(),
5112 std::min(lhsAddr.getAlignment(), rhsAddr.getAlignment()));
5113 AlignmentSource alignSource =
5114 std::max(Info.LHS->getBaseInfo().getAlignmentSource(),
5115 Info.RHS->getBaseInfo().getAlignmentSource());
5116 TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForConditionalOperator(
5117 Info.LHS->getTBAAInfo(), Info.RHS->getTBAAInfo());
5118 return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
5119 TBAAInfo);
5120 } else {
5121 assert((Info.LHS || Info.RHS) &&
5122 "both operands of glvalue conditional are throw-expressions?");
5123 return Info.LHS ? *Info.LHS : *Info.RHS;
5124 }
5125 }
5126
5127 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
5128 /// type. If the cast is to a reference, we can have the usual lvalue result,
5129 /// otherwise if a cast is needed by the code generator in an lvalue context,
5130 /// then it must mean that we need the address of an aggregate in order to
5131 /// access one of its members. This can happen for all the reasons that casts
5132 /// are permitted with aggregate result, including noop aggregate casts, and
5133 /// cast from scalar to union.
EmitCastLValue(const CastExpr * E)5134 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
5135 switch (E->getCastKind()) {
5136 case CK_ToVoid:
5137 case CK_BitCast:
5138 case CK_LValueToRValueBitCast:
5139 case CK_ArrayToPointerDecay:
5140 case CK_FunctionToPointerDecay:
5141 case CK_NullToMemberPointer:
5142 case CK_NullToPointer:
5143 case CK_IntegralToPointer:
5144 case CK_PointerToIntegral:
5145 case CK_PointerToBoolean:
5146 case CK_IntegralCast:
5147 case CK_BooleanToSignedIntegral:
5148 case CK_IntegralToBoolean:
5149 case CK_IntegralToFloating:
5150 case CK_FloatingToIntegral:
5151 case CK_FloatingToBoolean:
5152 case CK_FloatingCast:
5153 case CK_FloatingRealToComplex:
5154 case CK_FloatingComplexToReal:
5155 case CK_FloatingComplexToBoolean:
5156 case CK_FloatingComplexCast:
5157 case CK_FloatingComplexToIntegralComplex:
5158 case CK_IntegralRealToComplex:
5159 case CK_IntegralComplexToReal:
5160 case CK_IntegralComplexToBoolean:
5161 case CK_IntegralComplexCast:
5162 case CK_IntegralComplexToFloatingComplex:
5163 case CK_DerivedToBaseMemberPointer:
5164 case CK_BaseToDerivedMemberPointer:
5165 case CK_MemberPointerToBoolean:
5166 case CK_ReinterpretMemberPointer:
5167 case CK_AnyPointerToBlockPointerCast:
5168 case CK_ARCProduceObject:
5169 case CK_ARCConsumeObject:
5170 case CK_ARCReclaimReturnedObject:
5171 case CK_ARCExtendBlockObject:
5172 case CK_CopyAndAutoreleaseBlockObject:
5173 case CK_IntToOCLSampler:
5174 case CK_FloatingToFixedPoint:
5175 case CK_FixedPointToFloating:
5176 case CK_FixedPointCast:
5177 case CK_FixedPointToBoolean:
5178 case CK_FixedPointToIntegral:
5179 case CK_IntegralToFixedPoint:
5180 case CK_MatrixCast:
5181 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
5182
5183 case CK_Dependent:
5184 llvm_unreachable("dependent cast kind in IR gen!");
5185
5186 case CK_BuiltinFnToFnPtr:
5187 llvm_unreachable("builtin functions are handled elsewhere");
5188
5189 // These are never l-values; just use the aggregate emission code.
5190 case CK_NonAtomicToAtomic:
5191 case CK_AtomicToNonAtomic:
5192 return EmitAggExprToLValue(E);
5193
5194 case CK_Dynamic: {
5195 LValue LV = EmitLValue(E->getSubExpr());
5196 Address V = LV.getAddress(*this);
5197 const auto *DCE = cast<CXXDynamicCastExpr>(E);
5198 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType());
5199 }
5200
5201 case CK_ConstructorConversion:
5202 case CK_UserDefinedConversion:
5203 case CK_CPointerToObjCPointerCast:
5204 case CK_BlockPointerToObjCPointerCast:
5205 case CK_LValueToRValue:
5206 return EmitLValue(E->getSubExpr());
5207
5208 case CK_NoOp: {
5209 // CK_NoOp can model a qualification conversion, which can remove an array
5210 // bound and change the IR type.
5211 // FIXME: Once pointee types are removed from IR, remove this.
5212 LValue LV = EmitLValue(E->getSubExpr());
5213 // Propagate the volatile qualifer to LValue, if exist in E.
5214 if (E->changesVolatileQualification())
5215 LV.getQuals() = E->getType().getQualifiers();
5216 if (LV.isSimple()) {
5217 Address V = LV.getAddress(*this);
5218 if (V.isValid()) {
5219 llvm::Type *T = ConvertTypeForMem(E->getType());
5220 if (V.getElementType() != T)
5221 LV.setAddress(V.withElementType(T));
5222 }
5223 }
5224 return LV;
5225 }
5226
5227 case CK_UncheckedDerivedToBase:
5228 case CK_DerivedToBase: {
5229 const auto *DerivedClassTy =
5230 E->getSubExpr()->getType()->castAs<RecordType>();
5231 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
5232
5233 LValue LV = EmitLValue(E->getSubExpr());
5234 Address This = LV.getAddress(*this);
5235
5236 // Perform the derived-to-base conversion
5237 Address Base = GetAddressOfBaseClass(
5238 This, DerivedClassDecl, E->path_begin(), E->path_end(),
5239 /*NullCheckValue=*/false, E->getExprLoc());
5240
5241 // TODO: Support accesses to members of base classes in TBAA. For now, we
5242 // conservatively pretend that the complete object is of the base class
5243 // type.
5244 return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
5245 CGM.getTBAAInfoForSubobject(LV, E->getType()));
5246 }
5247 case CK_ToUnion:
5248 return EmitAggExprToLValue(E);
5249 case CK_BaseToDerived: {
5250 const auto *DerivedClassTy = E->getType()->castAs<RecordType>();
5251 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
5252
5253 LValue LV = EmitLValue(E->getSubExpr());
5254
5255 // Perform the base-to-derived conversion
5256 Address Derived = GetAddressOfDerivedClass(
5257 LV.getAddress(*this), DerivedClassDecl, E->path_begin(), E->path_end(),
5258 /*NullCheckValue=*/false);
5259
5260 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is
5261 // performed and the object is not of the derived type.
5262 if (sanitizePerformTypeCheck())
5263 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(),
5264 Derived.getPointer(), E->getType());
5265
5266 if (SanOpts.has(SanitizerKind::CFIDerivedCast))
5267 EmitVTablePtrCheckForCast(E->getType(), Derived,
5268 /*MayBeNull=*/false, CFITCK_DerivedCast,
5269 E->getBeginLoc());
5270
5271 return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(),
5272 CGM.getTBAAInfoForSubobject(LV, E->getType()));
5273 }
5274 case CK_LValueBitCast: {
5275 // This must be a reinterpret_cast (or c-style equivalent).
5276 const auto *CE = cast<ExplicitCastExpr>(E);
5277
5278 CGM.EmitExplicitCastExprType(CE, this);
5279 LValue LV = EmitLValue(E->getSubExpr());
5280 Address V = LV.getAddress(*this).withElementType(
5281 ConvertTypeForMem(CE->getTypeAsWritten()->getPointeeType()));
5282
5283 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast))
5284 EmitVTablePtrCheckForCast(E->getType(), V,
5285 /*MayBeNull=*/false, CFITCK_UnrelatedCast,
5286 E->getBeginLoc());
5287
5288 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
5289 CGM.getTBAAInfoForSubobject(LV, E->getType()));
5290 }
5291 case CK_AddressSpaceConversion: {
5292 LValue LV = EmitLValue(E->getSubExpr());
5293 QualType DestTy = getContext().getPointerType(E->getType());
5294 llvm::Value *V = getTargetHooks().performAddrSpaceCast(
5295 *this, LV.getPointer(*this),
5296 E->getSubExpr()->getType().getAddressSpace(),
5297 E->getType().getAddressSpace(), ConvertType(DestTy));
5298 return MakeAddrLValue(Address(V, ConvertTypeForMem(E->getType()),
5299 LV.getAddress(*this).getAlignment()),
5300 E->getType(), LV.getBaseInfo(), LV.getTBAAInfo());
5301 }
5302 case CK_ObjCObjectLValueCast: {
5303 LValue LV = EmitLValue(E->getSubExpr());
5304 Address V = LV.getAddress(*this).withElementType(ConvertType(E->getType()));
5305 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(),
5306 CGM.getTBAAInfoForSubobject(LV, E->getType()));
5307 }
5308 case CK_ZeroToOCLOpaqueType:
5309 llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid");
5310
5311 case CK_VectorSplat: {
5312 // LValue results of vector splats are only supported in HLSL.
5313 if (!getLangOpts().HLSL)
5314 return EmitUnsupportedLValue(E, "unexpected cast lvalue");
5315 return EmitLValue(E->getSubExpr());
5316 }
5317 }
5318
5319 llvm_unreachable("Unhandled lvalue cast kind?");
5320 }
5321
EmitOpaqueValueLValue(const OpaqueValueExpr * e)5322 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) {
5323 assert(OpaqueValueMappingData::shouldBindAsLValue(e));
5324 return getOrCreateOpaqueLValueMapping(e);
5325 }
5326
5327 LValue
getOrCreateOpaqueLValueMapping(const OpaqueValueExpr * e)5328 CodeGenFunction::getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e) {
5329 assert(OpaqueValueMapping::shouldBindAsLValue(e));
5330
5331 llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator
5332 it = OpaqueLValues.find(e);
5333
5334 if (it != OpaqueLValues.end())
5335 return it->second;
5336
5337 assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted");
5338 return EmitLValue(e->getSourceExpr());
5339 }
5340
5341 RValue
getOrCreateOpaqueRValueMapping(const OpaqueValueExpr * e)5342 CodeGenFunction::getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e) {
5343 assert(!OpaqueValueMapping::shouldBindAsLValue(e));
5344
5345 llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator
5346 it = OpaqueRValues.find(e);
5347
5348 if (it != OpaqueRValues.end())
5349 return it->second;
5350
5351 assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted");
5352 return EmitAnyExpr(e->getSourceExpr());
5353 }
5354
EmitRValueForField(LValue LV,const FieldDecl * FD,SourceLocation Loc)5355 RValue CodeGenFunction::EmitRValueForField(LValue LV,
5356 const FieldDecl *FD,
5357 SourceLocation Loc) {
5358 QualType FT = FD->getType();
5359 LValue FieldLV = EmitLValueForField(LV, FD);
5360 switch (getEvaluationKind(FT)) {
5361 case TEK_Complex:
5362 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc));
5363 case TEK_Aggregate:
5364 return FieldLV.asAggregateRValue(*this);
5365 case TEK_Scalar:
5366 // This routine is used to load fields one-by-one to perform a copy, so
5367 // don't load reference fields.
5368 if (FD->getType()->isReferenceType())
5369 return RValue::get(FieldLV.getPointer(*this));
5370 // Call EmitLoadOfScalar except when the lvalue is a bitfield to emit a
5371 // primitive load.
5372 if (FieldLV.isBitField())
5373 return EmitLoadOfLValue(FieldLV, Loc);
5374 return RValue::get(EmitLoadOfScalar(FieldLV, Loc));
5375 }
5376 llvm_unreachable("bad evaluation kind");
5377 }
5378
5379 //===--------------------------------------------------------------------===//
5380 // Expression Emission
5381 //===--------------------------------------------------------------------===//
5382
EmitCallExpr(const CallExpr * E,ReturnValueSlot ReturnValue)5383 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E,
5384 ReturnValueSlot ReturnValue) {
5385 // Builtins never have block type.
5386 if (E->getCallee()->getType()->isBlockPointerType())
5387 return EmitBlockCallExpr(E, ReturnValue);
5388
5389 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E))
5390 return EmitCXXMemberCallExpr(CE, ReturnValue);
5391
5392 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E))
5393 return EmitCUDAKernelCallExpr(CE, ReturnValue);
5394
5395 // A CXXOperatorCallExpr is created even for explicit object methods, but
5396 // these should be treated like static function call.
5397 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E))
5398 if (const auto *MD =
5399 dyn_cast_if_present<CXXMethodDecl>(CE->getCalleeDecl());
5400 MD && MD->isImplicitObjectMemberFunction())
5401 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue);
5402
5403 CGCallee callee = EmitCallee(E->getCallee());
5404
5405 if (callee.isBuiltin()) {
5406 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(),
5407 E, ReturnValue);
5408 }
5409
5410 if (callee.isPseudoDestructor()) {
5411 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr());
5412 }
5413
5414 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue);
5415 }
5416
5417 /// Emit a CallExpr without considering whether it might be a subclass.
EmitSimpleCallExpr(const CallExpr * E,ReturnValueSlot ReturnValue)5418 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
5419 ReturnValueSlot ReturnValue) {
5420 CGCallee Callee = EmitCallee(E->getCallee());
5421 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
5422 }
5423
5424 // Detect the unusual situation where an inline version is shadowed by a
5425 // non-inline version. In that case we should pick the external one
5426 // everywhere. That's GCC behavior too.
OnlyHasInlineBuiltinDeclaration(const FunctionDecl * FD)5427 static bool OnlyHasInlineBuiltinDeclaration(const FunctionDecl *FD) {
5428 for (const FunctionDecl *PD = FD; PD; PD = PD->getPreviousDecl())
5429 if (!PD->isInlineBuiltinDeclaration())
5430 return false;
5431 return true;
5432 }
5433
EmitDirectCallee(CodeGenFunction & CGF,GlobalDecl GD)5434 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, GlobalDecl GD) {
5435 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
5436
5437 if (auto builtinID = FD->getBuiltinID()) {
5438 std::string NoBuiltinFD = ("no-builtin-" + FD->getName()).str();
5439 std::string NoBuiltins = "no-builtins";
5440
5441 StringRef Ident = CGF.CGM.getMangledName(GD);
5442 std::string FDInlineName = (Ident + ".inline").str();
5443
5444 bool IsPredefinedLibFunction =
5445 CGF.getContext().BuiltinInfo.isPredefinedLibFunction(builtinID);
5446 bool HasAttributeNoBuiltin =
5447 CGF.CurFn->getAttributes().hasFnAttr(NoBuiltinFD) ||
5448 CGF.CurFn->getAttributes().hasFnAttr(NoBuiltins);
5449
5450 // When directing calling an inline builtin, call it through it's mangled
5451 // name to make it clear it's not the actual builtin.
5452 if (CGF.CurFn->getName() != FDInlineName &&
5453 OnlyHasInlineBuiltinDeclaration(FD)) {
5454 llvm::Constant *CalleePtr = EmitFunctionDeclPointer(CGF.CGM, GD);
5455 llvm::Function *Fn = llvm::cast<llvm::Function>(CalleePtr);
5456 llvm::Module *M = Fn->getParent();
5457 llvm::Function *Clone = M->getFunction(FDInlineName);
5458 if (!Clone) {
5459 Clone = llvm::Function::Create(Fn->getFunctionType(),
5460 llvm::GlobalValue::InternalLinkage,
5461 Fn->getAddressSpace(), FDInlineName, M);
5462 Clone->addFnAttr(llvm::Attribute::AlwaysInline);
5463 }
5464 return CGCallee::forDirect(Clone, GD);
5465 }
5466
5467 // Replaceable builtins provide their own implementation of a builtin. If we
5468 // are in an inline builtin implementation, avoid trivial infinite
5469 // recursion. Honor __attribute__((no_builtin("foo"))) or
5470 // __attribute__((no_builtin)) on the current function unless foo is
5471 // not a predefined library function which means we must generate the
5472 // builtin no matter what.
5473 else if (!IsPredefinedLibFunction || !HasAttributeNoBuiltin)
5474 return CGCallee::forBuiltin(builtinID, FD);
5475 }
5476
5477 llvm::Constant *CalleePtr = EmitFunctionDeclPointer(CGF.CGM, GD);
5478 if (CGF.CGM.getLangOpts().CUDA && !CGF.CGM.getLangOpts().CUDAIsDevice &&
5479 FD->hasAttr<CUDAGlobalAttr>())
5480 CalleePtr = CGF.CGM.getCUDARuntime().getKernelStub(
5481 cast<llvm::GlobalValue>(CalleePtr->stripPointerCasts()));
5482
5483 return CGCallee::forDirect(CalleePtr, GD);
5484 }
5485
EmitCallee(const Expr * E)5486 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
5487 E = E->IgnoreParens();
5488
5489 // Look through function-to-pointer decay.
5490 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
5491 if (ICE->getCastKind() == CK_FunctionToPointerDecay ||
5492 ICE->getCastKind() == CK_BuiltinFnToFnPtr) {
5493 return EmitCallee(ICE->getSubExpr());
5494 }
5495
5496 // Resolve direct calls.
5497 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) {
5498 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) {
5499 return EmitDirectCallee(*this, FD);
5500 }
5501 } else if (auto ME = dyn_cast<MemberExpr>(E)) {
5502 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) {
5503 EmitIgnoredExpr(ME->getBase());
5504 return EmitDirectCallee(*this, FD);
5505 }
5506
5507 // Look through template substitutions.
5508 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) {
5509 return EmitCallee(NTTP->getReplacement());
5510
5511 // Treat pseudo-destructor calls differently.
5512 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) {
5513 return CGCallee::forPseudoDestructor(PDE);
5514 }
5515
5516 // Otherwise, we have an indirect reference.
5517 llvm::Value *calleePtr;
5518 QualType functionType;
5519 if (auto ptrType = E->getType()->getAs<PointerType>()) {
5520 calleePtr = EmitScalarExpr(E);
5521 functionType = ptrType->getPointeeType();
5522 } else {
5523 functionType = E->getType();
5524 calleePtr = EmitLValue(E, KnownNonNull).getPointer(*this);
5525 }
5526 assert(functionType->isFunctionType());
5527
5528 GlobalDecl GD;
5529 if (const auto *VD =
5530 dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee()))
5531 GD = GlobalDecl(VD);
5532
5533 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD);
5534 CGCallee callee(calleeInfo, calleePtr);
5535 return callee;
5536 }
5537
EmitBinaryOperatorLValue(const BinaryOperator * E)5538 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) {
5539 // Comma expressions just emit their LHS then their RHS as an l-value.
5540 if (E->getOpcode() == BO_Comma) {
5541 EmitIgnoredExpr(E->getLHS());
5542 EnsureInsertPoint();
5543 return EmitLValue(E->getRHS());
5544 }
5545
5546 if (E->getOpcode() == BO_PtrMemD ||
5547 E->getOpcode() == BO_PtrMemI)
5548 return EmitPointerToDataMemberBinaryExpr(E);
5549
5550 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value");
5551
5552 // Note that in all of these cases, __block variables need the RHS
5553 // evaluated first just in case the variable gets moved by the RHS.
5554
5555 switch (getEvaluationKind(E->getType())) {
5556 case TEK_Scalar: {
5557 switch (E->getLHS()->getType().getObjCLifetime()) {
5558 case Qualifiers::OCL_Strong:
5559 return EmitARCStoreStrong(E, /*ignored*/ false).first;
5560
5561 case Qualifiers::OCL_Autoreleasing:
5562 return EmitARCStoreAutoreleasing(E).first;
5563
5564 // No reason to do any of these differently.
5565 case Qualifiers::OCL_None:
5566 case Qualifiers::OCL_ExplicitNone:
5567 case Qualifiers::OCL_Weak:
5568 break;
5569 }
5570
5571 RValue RV = EmitAnyExpr(E->getRHS());
5572 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store);
5573 if (RV.isScalar())
5574 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc());
5575 EmitStoreThroughLValue(RV, LV);
5576 if (getLangOpts().OpenMP)
5577 CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this,
5578 E->getLHS());
5579 return LV;
5580 }
5581
5582 case TEK_Complex:
5583 return EmitComplexAssignmentLValue(E);
5584
5585 case TEK_Aggregate:
5586 return EmitAggExprToLValue(E);
5587 }
5588 llvm_unreachable("bad evaluation kind");
5589 }
5590
EmitCallExprLValue(const CallExpr * E)5591 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) {
5592 RValue RV = EmitCallExpr(E);
5593
5594 if (!RV.isScalar())
5595 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
5596 AlignmentSource::Decl);
5597
5598 assert(E->getCallReturnType(getContext())->isReferenceType() &&
5599 "Can't have a scalar return unless the return type is a "
5600 "reference type!");
5601
5602 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
5603 }
5604
EmitVAArgExprLValue(const VAArgExpr * E)5605 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) {
5606 // FIXME: This shouldn't require another copy.
5607 return EmitAggExprToLValue(E);
5608 }
5609
EmitCXXConstructLValue(const CXXConstructExpr * E)5610 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) {
5611 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor()
5612 && "binding l-value to type which needs a temporary");
5613 AggValueSlot Slot = CreateAggTemp(E->getType());
5614 EmitCXXConstructExpr(E, Slot);
5615 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
5616 }
5617
5618 LValue
EmitCXXTypeidLValue(const CXXTypeidExpr * E)5619 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) {
5620 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType());
5621 }
5622
EmitCXXUuidofExpr(const CXXUuidofExpr * E)5623 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) {
5624 return CGM.GetAddrOfMSGuidDecl(E->getGuidDecl())
5625 .withElementType(ConvertType(E->getType()));
5626 }
5627
EmitCXXUuidofLValue(const CXXUuidofExpr * E)5628 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) {
5629 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(),
5630 AlignmentSource::Decl);
5631 }
5632
5633 LValue
EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr * E)5634 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) {
5635 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue");
5636 Slot.setExternallyDestructed();
5637 EmitAggExpr(E->getSubExpr(), Slot);
5638 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress());
5639 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl);
5640 }
5641
EmitObjCMessageExprLValue(const ObjCMessageExpr * E)5642 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) {
5643 RValue RV = EmitObjCMessageExpr(E);
5644
5645 if (!RV.isScalar())
5646 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
5647 AlignmentSource::Decl);
5648
5649 assert(E->getMethodDecl()->getReturnType()->isReferenceType() &&
5650 "Can't have a scalar return unless the return type is a "
5651 "reference type!");
5652
5653 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType());
5654 }
5655
EmitObjCSelectorLValue(const ObjCSelectorExpr * E)5656 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) {
5657 Address V =
5658 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector());
5659 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl);
5660 }
5661
EmitIvarOffset(const ObjCInterfaceDecl * Interface,const ObjCIvarDecl * Ivar)5662 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface,
5663 const ObjCIvarDecl *Ivar) {
5664 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar);
5665 }
5666
5667 llvm::Value *
EmitIvarOffsetAsPointerDiff(const ObjCInterfaceDecl * Interface,const ObjCIvarDecl * Ivar)5668 CodeGenFunction::EmitIvarOffsetAsPointerDiff(const ObjCInterfaceDecl *Interface,
5669 const ObjCIvarDecl *Ivar) {
5670 llvm::Value *OffsetValue = EmitIvarOffset(Interface, Ivar);
5671 QualType PointerDiffType = getContext().getPointerDiffType();
5672 return Builder.CreateZExtOrTrunc(OffsetValue,
5673 getTypes().ConvertType(PointerDiffType));
5674 }
5675
EmitLValueForIvar(QualType ObjectTy,llvm::Value * BaseValue,const ObjCIvarDecl * Ivar,unsigned CVRQualifiers)5676 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy,
5677 llvm::Value *BaseValue,
5678 const ObjCIvarDecl *Ivar,
5679 unsigned CVRQualifiers) {
5680 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue,
5681 Ivar, CVRQualifiers);
5682 }
5683
EmitObjCIvarRefLValue(const ObjCIvarRefExpr * E)5684 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) {
5685 // FIXME: A lot of the code below could be shared with EmitMemberExpr.
5686 llvm::Value *BaseValue = nullptr;
5687 const Expr *BaseExpr = E->getBase();
5688 Qualifiers BaseQuals;
5689 QualType ObjectTy;
5690 if (E->isArrow()) {
5691 BaseValue = EmitScalarExpr(BaseExpr);
5692 ObjectTy = BaseExpr->getType()->getPointeeType();
5693 BaseQuals = ObjectTy.getQualifiers();
5694 } else {
5695 LValue BaseLV = EmitLValue(BaseExpr);
5696 BaseValue = BaseLV.getPointer(*this);
5697 ObjectTy = BaseExpr->getType();
5698 BaseQuals = ObjectTy.getQualifiers();
5699 }
5700
5701 LValue LV =
5702 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(),
5703 BaseQuals.getCVRQualifiers());
5704 setObjCGCLValueClass(getContext(), E, LV);
5705 return LV;
5706 }
5707
EmitStmtExprLValue(const StmtExpr * E)5708 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) {
5709 // Can only get l-value for message expression returning aggregate type
5710 RValue RV = EmitAnyExprToTemp(E);
5711 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(),
5712 AlignmentSource::Decl);
5713 }
5714
EmitCall(QualType CalleeType,const CGCallee & OrigCallee,const CallExpr * E,ReturnValueSlot ReturnValue,llvm::Value * Chain)5715 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee,
5716 const CallExpr *E, ReturnValueSlot ReturnValue,
5717 llvm::Value *Chain) {
5718 // Get the actual function type. The callee type will always be a pointer to
5719 // function type or a block pointer type.
5720 assert(CalleeType->isFunctionPointerType() &&
5721 "Call must have function pointer type!");
5722
5723 const Decl *TargetDecl =
5724 OrigCallee.getAbstractInfo().getCalleeDecl().getDecl();
5725
5726 assert((!isa_and_present<FunctionDecl>(TargetDecl) ||
5727 !cast<FunctionDecl>(TargetDecl)->isImmediateFunction()) &&
5728 "trying to emit a call to an immediate function");
5729
5730 CalleeType = getContext().getCanonicalType(CalleeType);
5731
5732 auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType();
5733
5734 CGCallee Callee = OrigCallee;
5735
5736 if (SanOpts.has(SanitizerKind::Function) &&
5737 (!TargetDecl || !isa<FunctionDecl>(TargetDecl)) &&
5738 !isa<FunctionNoProtoType>(PointeeType)) {
5739 if (llvm::Constant *PrefixSig =
5740 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) {
5741 SanitizerScope SanScope(this);
5742 auto *TypeHash = getUBSanFunctionTypeHash(PointeeType);
5743
5744 llvm::Type *PrefixSigType = PrefixSig->getType();
5745 llvm::StructType *PrefixStructTy = llvm::StructType::get(
5746 CGM.getLLVMContext(), {PrefixSigType, Int32Ty}, /*isPacked=*/true);
5747
5748 llvm::Value *CalleePtr = Callee.getFunctionPointer();
5749
5750 // On 32-bit Arm, the low bit of a function pointer indicates whether
5751 // it's using the Arm or Thumb instruction set. The actual first
5752 // instruction lives at the same address either way, so we must clear
5753 // that low bit before using the function address to find the prefix
5754 // structure.
5755 //
5756 // This applies to both Arm and Thumb target triples, because
5757 // either one could be used in an interworking context where it
5758 // might be passed function pointers of both types.
5759 llvm::Value *AlignedCalleePtr;
5760 if (CGM.getTriple().isARM() || CGM.getTriple().isThumb()) {
5761 llvm::Value *CalleeAddress =
5762 Builder.CreatePtrToInt(CalleePtr, IntPtrTy);
5763 llvm::Value *Mask = llvm::ConstantInt::get(IntPtrTy, ~1);
5764 llvm::Value *AlignedCalleeAddress =
5765 Builder.CreateAnd(CalleeAddress, Mask);
5766 AlignedCalleePtr =
5767 Builder.CreateIntToPtr(AlignedCalleeAddress, CalleePtr->getType());
5768 } else {
5769 AlignedCalleePtr = CalleePtr;
5770 }
5771
5772 llvm::Value *CalleePrefixStruct = AlignedCalleePtr;
5773 llvm::Value *CalleeSigPtr =
5774 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, -1, 0);
5775 llvm::Value *CalleeSig =
5776 Builder.CreateAlignedLoad(PrefixSigType, CalleeSigPtr, getIntAlign());
5777 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig);
5778
5779 llvm::BasicBlock *Cont = createBasicBlock("cont");
5780 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck");
5781 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont);
5782
5783 EmitBlock(TypeCheck);
5784 llvm::Value *CalleeTypeHash = Builder.CreateAlignedLoad(
5785 Int32Ty,
5786 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, -1, 1),
5787 getPointerAlign());
5788 llvm::Value *CalleeTypeHashMatch =
5789 Builder.CreateICmpEQ(CalleeTypeHash, TypeHash);
5790 llvm::Constant *StaticData[] = {EmitCheckSourceLocation(E->getBeginLoc()),
5791 EmitCheckTypeDescriptor(CalleeType)};
5792 EmitCheck(std::make_pair(CalleeTypeHashMatch, SanitizerKind::Function),
5793 SanitizerHandler::FunctionTypeMismatch, StaticData,
5794 {CalleePtr});
5795
5796 Builder.CreateBr(Cont);
5797 EmitBlock(Cont);
5798 }
5799 }
5800
5801 const auto *FnType = cast<FunctionType>(PointeeType);
5802
5803 // If we are checking indirect calls and this call is indirect, check that the
5804 // function pointer is a member of the bit set for the function type.
5805 if (SanOpts.has(SanitizerKind::CFIICall) &&
5806 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
5807 SanitizerScope SanScope(this);
5808 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall);
5809
5810 llvm::Metadata *MD;
5811 if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers)
5812 MD = CGM.CreateMetadataIdentifierGeneralized(QualType(FnType, 0));
5813 else
5814 MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0));
5815
5816 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD);
5817
5818 llvm::Value *CalleePtr = Callee.getFunctionPointer();
5819 llvm::Value *TypeTest = Builder.CreateCall(
5820 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CalleePtr, TypeId});
5821
5822 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD);
5823 llvm::Constant *StaticData[] = {
5824 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall),
5825 EmitCheckSourceLocation(E->getBeginLoc()),
5826 EmitCheckTypeDescriptor(QualType(FnType, 0)),
5827 };
5828 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) {
5829 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId,
5830 CalleePtr, StaticData);
5831 } else {
5832 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall),
5833 SanitizerHandler::CFICheckFail, StaticData,
5834 {CalleePtr, llvm::UndefValue::get(IntPtrTy)});
5835 }
5836 }
5837
5838 CallArgList Args;
5839 if (Chain)
5840 Args.add(RValue::get(Chain), CGM.getContext().VoidPtrTy);
5841
5842 // C++17 requires that we evaluate arguments to a call using assignment syntax
5843 // right-to-left, and that we evaluate arguments to certain other operators
5844 // left-to-right. Note that we allow this to override the order dictated by
5845 // the calling convention on the MS ABI, which means that parameter
5846 // destruction order is not necessarily reverse construction order.
5847 // FIXME: Revisit this based on C++ committee response to unimplementability.
5848 EvaluationOrder Order = EvaluationOrder::Default;
5849 bool StaticOperator = false;
5850 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) {
5851 if (OCE->isAssignmentOp())
5852 Order = EvaluationOrder::ForceRightToLeft;
5853 else {
5854 switch (OCE->getOperator()) {
5855 case OO_LessLess:
5856 case OO_GreaterGreater:
5857 case OO_AmpAmp:
5858 case OO_PipePipe:
5859 case OO_Comma:
5860 case OO_ArrowStar:
5861 Order = EvaluationOrder::ForceLeftToRight;
5862 break;
5863 default:
5864 break;
5865 }
5866 }
5867
5868 if (const auto *MD =
5869 dyn_cast_if_present<CXXMethodDecl>(OCE->getCalleeDecl());
5870 MD && MD->isStatic())
5871 StaticOperator = true;
5872 }
5873
5874 auto Arguments = E->arguments();
5875 if (StaticOperator) {
5876 // If we're calling a static operator, we need to emit the object argument
5877 // and ignore it.
5878 EmitIgnoredExpr(E->getArg(0));
5879 Arguments = drop_begin(Arguments, 1);
5880 }
5881 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), Arguments,
5882 E->getDirectCallee(), /*ParamsToSkip=*/0, Order);
5883
5884 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall(
5885 Args, FnType, /*ChainCall=*/Chain);
5886
5887 // C99 6.5.2.2p6:
5888 // If the expression that denotes the called function has a type
5889 // that does not include a prototype, [the default argument
5890 // promotions are performed]. If the number of arguments does not
5891 // equal the number of parameters, the behavior is undefined. If
5892 // the function is defined with a type that includes a prototype,
5893 // and either the prototype ends with an ellipsis (, ...) or the
5894 // types of the arguments after promotion are not compatible with
5895 // the types of the parameters, the behavior is undefined. If the
5896 // function is defined with a type that does not include a
5897 // prototype, and the types of the arguments after promotion are
5898 // not compatible with those of the parameters after promotion,
5899 // the behavior is undefined [except in some trivial cases].
5900 // That is, in the general case, we should assume that a call
5901 // through an unprototyped function type works like a *non-variadic*
5902 // call. The way we make this work is to cast to the exact type
5903 // of the promoted arguments.
5904 //
5905 // Chain calls use this same code path to add the invisible chain parameter
5906 // to the function type.
5907 if (isa<FunctionNoProtoType>(FnType) || Chain) {
5908 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo);
5909 int AS = Callee.getFunctionPointer()->getType()->getPointerAddressSpace();
5910 CalleeTy = CalleeTy->getPointerTo(AS);
5911
5912 llvm::Value *CalleePtr = Callee.getFunctionPointer();
5913 CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast");
5914 Callee.setFunctionPointer(CalleePtr);
5915 }
5916
5917 // HIP function pointer contains kernel handle when it is used in triple
5918 // chevron. The kernel stub needs to be loaded from kernel handle and used
5919 // as callee.
5920 if (CGM.getLangOpts().HIP && !CGM.getLangOpts().CUDAIsDevice &&
5921 isa<CUDAKernelCallExpr>(E) &&
5922 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) {
5923 llvm::Value *Handle = Callee.getFunctionPointer();
5924 auto *Stub = Builder.CreateLoad(
5925 Address(Handle, Handle->getType(), CGM.getPointerAlign()));
5926 Callee.setFunctionPointer(Stub);
5927 }
5928 llvm::CallBase *CallOrInvoke = nullptr;
5929 RValue Call = EmitCall(FnInfo, Callee, ReturnValue, Args, &CallOrInvoke,
5930 E == MustTailCall, E->getExprLoc());
5931
5932 // Generate function declaration DISuprogram in order to be used
5933 // in debug info about call sites.
5934 if (CGDebugInfo *DI = getDebugInfo()) {
5935 if (auto *CalleeDecl = dyn_cast_or_null<FunctionDecl>(TargetDecl)) {
5936 FunctionArgList Args;
5937 QualType ResTy = BuildFunctionArgList(CalleeDecl, Args);
5938 DI->EmitFuncDeclForCallSite(CallOrInvoke,
5939 DI->getFunctionType(CalleeDecl, ResTy, Args),
5940 CalleeDecl);
5941 }
5942 }
5943
5944 return Call;
5945 }
5946
5947 LValue CodeGenFunction::
EmitPointerToDataMemberBinaryExpr(const BinaryOperator * E)5948 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) {
5949 Address BaseAddr = Address::invalid();
5950 if (E->getOpcode() == BO_PtrMemI) {
5951 BaseAddr = EmitPointerWithAlignment(E->getLHS());
5952 } else {
5953 BaseAddr = EmitLValue(E->getLHS()).getAddress(*this);
5954 }
5955
5956 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS());
5957 const auto *MPT = E->getRHS()->getType()->castAs<MemberPointerType>();
5958
5959 LValueBaseInfo BaseInfo;
5960 TBAAAccessInfo TBAAInfo;
5961 Address MemberAddr =
5962 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo,
5963 &TBAAInfo);
5964
5965 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo);
5966 }
5967
5968 /// Given the address of a temporary variable, produce an r-value of
5969 /// its type.
convertTempToRValue(Address addr,QualType type,SourceLocation loc)5970 RValue CodeGenFunction::convertTempToRValue(Address addr,
5971 QualType type,
5972 SourceLocation loc) {
5973 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl);
5974 switch (getEvaluationKind(type)) {
5975 case TEK_Complex:
5976 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc));
5977 case TEK_Aggregate:
5978 return lvalue.asAggregateRValue(*this);
5979 case TEK_Scalar:
5980 return RValue::get(EmitLoadOfScalar(lvalue, loc));
5981 }
5982 llvm_unreachable("bad evaluation kind");
5983 }
5984
SetFPAccuracy(llvm::Value * Val,float Accuracy)5985 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) {
5986 assert(Val->getType()->isFPOrFPVectorTy());
5987 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val))
5988 return;
5989
5990 llvm::MDBuilder MDHelper(getLLVMContext());
5991 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy);
5992
5993 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node);
5994 }
5995
SetSqrtFPAccuracy(llvm::Value * Val)5996 void CodeGenFunction::SetSqrtFPAccuracy(llvm::Value *Val) {
5997 llvm::Type *EltTy = Val->getType()->getScalarType();
5998 if (!EltTy->isFloatTy())
5999 return;
6000
6001 if ((getLangOpts().OpenCL &&
6002 !CGM.getCodeGenOpts().OpenCLCorrectlyRoundedDivSqrt) ||
6003 (getLangOpts().HIP && getLangOpts().CUDAIsDevice &&
6004 !CGM.getCodeGenOpts().HIPCorrectlyRoundedDivSqrt)) {
6005 // OpenCL v1.1 s7.4: minimum accuracy of single precision / is 3ulp
6006 //
6007 // OpenCL v1.2 s5.6.4.2: The -cl-fp32-correctly-rounded-divide-sqrt
6008 // build option allows an application to specify that single precision
6009 // floating-point divide (x/y and 1/x) and sqrt used in the program
6010 // source are correctly rounded.
6011 //
6012 // TODO: CUDA has a prec-sqrt flag
6013 SetFPAccuracy(Val, 3.0f);
6014 }
6015 }
6016
SetDivFPAccuracy(llvm::Value * Val)6017 void CodeGenFunction::SetDivFPAccuracy(llvm::Value *Val) {
6018 llvm::Type *EltTy = Val->getType()->getScalarType();
6019 if (!EltTy->isFloatTy())
6020 return;
6021
6022 if ((getLangOpts().OpenCL &&
6023 !CGM.getCodeGenOpts().OpenCLCorrectlyRoundedDivSqrt) ||
6024 (getLangOpts().HIP && getLangOpts().CUDAIsDevice &&
6025 !CGM.getCodeGenOpts().HIPCorrectlyRoundedDivSqrt)) {
6026 // OpenCL v1.1 s7.4: minimum accuracy of single precision / is 2.5ulp
6027 //
6028 // OpenCL v1.2 s5.6.4.2: The -cl-fp32-correctly-rounded-divide-sqrt
6029 // build option allows an application to specify that single precision
6030 // floating-point divide (x/y and 1/x) and sqrt used in the program
6031 // source are correctly rounded.
6032 //
6033 // TODO: CUDA has a prec-div flag
6034 SetFPAccuracy(Val, 2.5f);
6035 }
6036 }
6037
6038 namespace {
6039 struct LValueOrRValue {
6040 LValue LV;
6041 RValue RV;
6042 };
6043 }
6044
emitPseudoObjectExpr(CodeGenFunction & CGF,const PseudoObjectExpr * E,bool forLValue,AggValueSlot slot)6045 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF,
6046 const PseudoObjectExpr *E,
6047 bool forLValue,
6048 AggValueSlot slot) {
6049 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
6050
6051 // Find the result expression, if any.
6052 const Expr *resultExpr = E->getResultExpr();
6053 LValueOrRValue result;
6054
6055 for (PseudoObjectExpr::const_semantics_iterator
6056 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
6057 const Expr *semantic = *i;
6058
6059 // If this semantic expression is an opaque value, bind it
6060 // to the result of its source expression.
6061 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
6062 // Skip unique OVEs.
6063 if (ov->isUnique()) {
6064 assert(ov != resultExpr &&
6065 "A unique OVE cannot be used as the result expression");
6066 continue;
6067 }
6068
6069 // If this is the result expression, we may need to evaluate
6070 // directly into the slot.
6071 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
6072 OVMA opaqueData;
6073 if (ov == resultExpr && ov->isPRValue() && !forLValue &&
6074 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) {
6075 CGF.EmitAggExpr(ov->getSourceExpr(), slot);
6076 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(),
6077 AlignmentSource::Decl);
6078 opaqueData = OVMA::bind(CGF, ov, LV);
6079 result.RV = slot.asRValue();
6080
6081 // Otherwise, emit as normal.
6082 } else {
6083 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
6084
6085 // If this is the result, also evaluate the result now.
6086 if (ov == resultExpr) {
6087 if (forLValue)
6088 result.LV = CGF.EmitLValue(ov);
6089 else
6090 result.RV = CGF.EmitAnyExpr(ov, slot);
6091 }
6092 }
6093
6094 opaques.push_back(opaqueData);
6095
6096 // Otherwise, if the expression is the result, evaluate it
6097 // and remember the result.
6098 } else if (semantic == resultExpr) {
6099 if (forLValue)
6100 result.LV = CGF.EmitLValue(semantic);
6101 else
6102 result.RV = CGF.EmitAnyExpr(semantic, slot);
6103
6104 // Otherwise, evaluate the expression in an ignored context.
6105 } else {
6106 CGF.EmitIgnoredExpr(semantic);
6107 }
6108 }
6109
6110 // Unbind all the opaques now.
6111 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
6112 opaques[i].unbind(CGF);
6113
6114 return result;
6115 }
6116
EmitPseudoObjectRValue(const PseudoObjectExpr * E,AggValueSlot slot)6117 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E,
6118 AggValueSlot slot) {
6119 return emitPseudoObjectExpr(*this, E, false, slot).RV;
6120 }
6121
EmitPseudoObjectLValue(const PseudoObjectExpr * E)6122 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) {
6123 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV;
6124 }
6125