clang  14.0.0git
CGExpr.cpp
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1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This contains code to emit Expr nodes as LLVM code.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "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/Basic/Builtins.h"
32 #include "llvm/ADT/Hashing.h"
33 #include "llvm/ADT/StringExtras.h"
34 #include "llvm/IR/DataLayout.h"
35 #include "llvm/IR/Intrinsics.h"
36 #include "llvm/IR/LLVMContext.h"
37 #include "llvm/IR/MDBuilder.h"
38 #include "llvm/IR/MatrixBuilder.h"
39 #include "llvm/Support/ConvertUTF.h"
40 #include "llvm/Support/MathExtras.h"
41 #include "llvm/Support/Path.h"
42 #include "llvm/Support/SaveAndRestore.h"
43 #include "llvm/Transforms/Utils/SanitizerStats.h"
44 
45 #include <string>
46 
47 using namespace clang;
48 using namespace CodeGen;
49 
50 //===--------------------------------------------------------------------===//
51 // Miscellaneous Helper Methods
52 //===--------------------------------------------------------------------===//
53 
55  unsigned addressSpace =
56  cast<llvm::PointerType>(value->getType())->getAddressSpace();
57 
58  llvm::PointerType *destType = Int8PtrTy;
59  if (addressSpace)
60  destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace);
61 
62  if (value->getType() == destType) return value;
63  return Builder.CreateBitCast(value, destType);
64 }
65 
66 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
67 /// block.
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);
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.
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.
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());
101  Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
102  }
103 
104  return Address(V, Ty, Align);
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.
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.
124  const Twine &Name) {
125  CharUnits Align =
126  CharUnits::fromQuantity(CGM.getDataLayout().getPrefTypeAlignment(Ty));
127  return CreateTempAlloca(Ty, Align, Name);
128 }
129 
132  return CreateTempAlloca(ConvertType(Ty), Align, Name);
133 }
134 
136  Address *Alloca) {
137  // FIXME: Should we prefer the preferred type alignment here?
138  return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca);
139 }
140 
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(
152  Builder.CreateBitCast(Result.getPointer(), VectorTy->getPointerTo()),
153  Result.getAlignment());
154  }
155  return Result;
156 }
157 
159  const Twine &Name) {
160  return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name);
161 }
162 
164  const Twine &Name) {
165  return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty),
166  Name);
167 }
168 
169 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
170 /// expression and compare the result against zero, returning an Int1Ty value.
172  PGO.setCurrentStmt(E);
173  if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) {
174  llvm::Value *MemPtr = EmitScalarExpr(E);
175  return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT);
176  }
177 
178  QualType BoolTy = getContext().BoolTy;
179  SourceLocation Loc = E->getExprLoc();
180  CGFPOptionsRAII FPOptsRAII(*this, E);
181  if (!E->getType()->isAnyComplexType())
182  return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc);
183 
184  return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy,
185  Loc);
186 }
187 
188 /// EmitIgnoredExpr - Emit code to compute the specified expression,
189 /// ignoring the result.
191  if (E->isPRValue())
192  return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true);
193 
194  // Just emit it as an l-value and drop the result.
195  EmitLValue(E);
196 }
197 
198 /// EmitAnyExpr - Emit code to compute the specified expression which
199 /// can have any type. The result is returned as an RValue struct.
200 /// If this is an aggregate expression, AggSlot indicates where the
201 /// result should be returned.
203  AggValueSlot aggSlot,
204  bool ignoreResult) {
205  switch (getEvaluationKind(E->getType())) {
206  case TEK_Scalar:
207  return RValue::get(EmitScalarExpr(E, ignoreResult));
208  case TEK_Complex:
209  return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult));
210  case TEK_Aggregate:
211  if (!ignoreResult && aggSlot.isIgnored())
212  aggSlot = CreateAggTemp(E->getType(), "agg-temp");
213  EmitAggExpr(E, aggSlot);
214  return aggSlot.asRValue();
215  }
216  llvm_unreachable("bad evaluation kind");
217 }
218 
219 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will
220 /// always be accessible even if no aggregate location is provided.
223 
225  AggSlot = CreateAggTemp(E->getType(), "agg.tmp");
226  return EmitAnyExpr(E, AggSlot);
227 }
228 
229 /// EmitAnyExprToMem - Evaluate an expression into a given memory
230 /// location.
232  Address Location,
233  Qualifiers Quals,
234  bool IsInit) {
235  // FIXME: This function should take an LValue as an argument.
236  switch (getEvaluationKind(E->getType())) {
237  case TEK_Complex:
239  /*isInit*/ false);
240  return;
241 
242  case TEK_Aggregate: {
243  EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals,
246  AggValueSlot::IsAliased_t(!IsInit),
248  return;
249  }
250 
251  case TEK_Scalar: {
252  RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false));
253  LValue LV = MakeAddrLValue(Location, E->getType());
254  EmitStoreThroughLValue(RV, LV);
255  return;
256  }
257  }
258  llvm_unreachable("bad evaluation kind");
259 }
260 
261 static void
263  const Expr *E, Address ReferenceTemporary) {
264  // Objective-C++ ARC:
265  // If we are binding a reference to a temporary that has ownership, we
266  // need to perform retain/release operations on the temporary.
267  //
268  // FIXME: This should be looking at E, not M.
269  if (auto Lifetime = M->getType().getObjCLifetime()) {
270  switch (Lifetime) {
273  // Carry on to normal cleanup handling.
274  break;
275 
277  // Nothing to do; cleaned up by an autorelease pool.
278  return;
279 
282  switch (StorageDuration Duration = M->getStorageDuration()) {
283  case SD_Static:
284  // Note: we intentionally do not register a cleanup to release
285  // the object on program termination.
286  return;
287 
288  case SD_Thread:
289  // FIXME: We should probably register a cleanup in this case.
290  return;
291 
292  case SD_Automatic:
293  case SD_FullExpression:
296  if (Lifetime == Qualifiers::OCL_Strong) {
297  const ValueDecl *VD = M->getExtendingDecl();
298  bool Precise =
299  VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>();
303  } else {
304  // __weak objects always get EH cleanups; otherwise, exceptions
305  // could cause really nasty crashes instead of mere leaks.
308  }
309  if (Duration == SD_FullExpression)
310  CGF.pushDestroy(CleanupKind, ReferenceTemporary,
311  M->getType(), *Destroy,
313  else
314  CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary,
315  M->getType(),
317  return;
318 
319  case SD_Dynamic:
320  llvm_unreachable("temporary cannot have dynamic storage duration");
321  }
322  llvm_unreachable("unknown storage duration");
323  }
324  }
325 
326  CXXDestructorDecl *ReferenceTemporaryDtor = nullptr;
327  if (const RecordType *RT =
329  // Get the destructor for the reference temporary.
330  auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl());
331  if (!ClassDecl->hasTrivialDestructor())
332  ReferenceTemporaryDtor = ClassDecl->getDestructor();
333  }
334 
335  if (!ReferenceTemporaryDtor)
336  return;
337 
338  // Call the destructor for the temporary.
339  switch (M->getStorageDuration()) {
340  case SD_Static:
341  case SD_Thread: {
342  llvm::FunctionCallee CleanupFn;
343  llvm::Constant *CleanupArg;
344  if (E->getType()->isArrayType()) {
345  CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper(
346  ReferenceTemporary, E->getType(),
348  dyn_cast_or_null<VarDecl>(M->getExtendingDecl()));
349  CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy);
350  } else {
351  CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor(
352  GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete));
353  CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer());
354  }
356  CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg);
357  break;
358  }
359 
360  case SD_FullExpression:
361  CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(),
363  CGF.getLangOpts().Exceptions);
364  break;
365 
366  case SD_Automatic:
368  ReferenceTemporary, E->getType(),
370  CGF.getLangOpts().Exceptions);
371  break;
372 
373  case SD_Dynamic:
374  llvm_unreachable("temporary cannot have dynamic storage duration");
375  }
376 }
377 
379  const MaterializeTemporaryExpr *M,
380  const Expr *Inner,
381  Address *Alloca = nullptr) {
382  auto &TCG = CGF.getTargetHooks();
383  switch (M->getStorageDuration()) {
384  case SD_FullExpression:
385  case SD_Automatic: {
386  // If we have a constant temporary array or record try to promote it into a
387  // constant global under the same rules a normal constant would've been
388  // promoted. This is easier on the optimizer and generally emits fewer
389  // instructions.
390  QualType Ty = Inner->getType();
391  if (CGF.CGM.getCodeGenOpts().MergeAllConstants &&
392  (Ty->isArrayType() || Ty->isRecordType()) &&
393  CGF.CGM.isTypeConstant(Ty, true))
394  if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) {
395  auto AS = CGF.CGM.GetGlobalConstantAddressSpace();
396  auto *GV = new llvm::GlobalVariable(
397  CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true,
398  llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr,
399  llvm::GlobalValue::NotThreadLocal,
401  CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty);
402  GV->setAlignment(alignment.getAsAlign());
403  llvm::Constant *C = GV;
404  if (AS != LangAS::Default)
405  C = TCG.performAddrSpaceCast(
406  CGF.CGM, GV, AS, LangAS::Default,
407  GV->getValueType()->getPointerTo(
409  // FIXME: Should we put the new global into a COMDAT?
410  return Address(C, alignment);
411  }
412  return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca);
413  }
414  case SD_Thread:
415  case SD_Static:
416  return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner);
417 
418  case SD_Dynamic:
419  llvm_unreachable("temporary can't have dynamic storage duration");
420  }
421  llvm_unreachable("unknown storage duration");
422 }
423 
424 /// Helper method to check if the underlying ABI is AAPCS
425 static bool isAAPCS(const TargetInfo &TargetInfo) {
426  return TargetInfo.getABI().startswith("aapcs");
427 }
428 
431  const Expr *E = M->getSubExpr();
432 
433  assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) ||
434  !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) &&
435  "Reference should never be pseudo-strong!");
436 
437  // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so
438  // as that will cause the lifetime adjustment to be lost for ARC
439  auto ownership = M->getType().getObjCLifetime();
440  if (ownership != Qualifiers::OCL_None &&
441  ownership != Qualifiers::OCL_ExplicitNone) {
442  Address Object = createReferenceTemporary(*this, M, E);
443  if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) {
444  Object = Address(llvm::ConstantExpr::getBitCast(Var,
446  ->getPointerTo(Object.getAddressSpace())),
447  Object.getAlignment());
448 
449  // createReferenceTemporary will promote the temporary to a global with a
450  // constant initializer if it can. It can only do this to a value of
451  // ARC-manageable type if the value is global and therefore "immune" to
452  // ref-counting operations. Therefore we have no need to emit either a
453  // dynamic initialization or a cleanup and we can just return the address
454  // of the temporary.
455  if (Var->hasInitializer())
456  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
457 
458  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
459  }
460  LValue RefTempDst = MakeAddrLValue(Object, M->getType(),
462 
463  switch (getEvaluationKind(E->getType())) {
464  default: llvm_unreachable("expected scalar or aggregate expression");
465  case TEK_Scalar:
466  EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false);
467  break;
468  case TEK_Aggregate: {
470  E->getType().getQualifiers(),
475  break;
476  }
477  }
478 
479  pushTemporaryCleanup(*this, M, E, Object);
480  return RefTempDst;
481  }
482 
485  E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
486 
487  for (const auto &Ignored : CommaLHSs)
488  EmitIgnoredExpr(Ignored);
489 
490  if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) {
491  if (opaque->getType()->isRecordType()) {
492  assert(Adjustments.empty());
493  return EmitOpaqueValueLValue(opaque);
494  }
495  }
496 
497  // Create and initialize the reference temporary.
498  Address Alloca = Address::invalid();
499  Address Object = createReferenceTemporary(*this, M, E, &Alloca);
500  if (auto *Var = dyn_cast<llvm::GlobalVariable>(
501  Object.getPointer()->stripPointerCasts())) {
502  Object = Address(llvm::ConstantExpr::getBitCast(
503  cast<llvm::Constant>(Object.getPointer()),
504  ConvertTypeForMem(E->getType())->getPointerTo()),
505  Object.getAlignment());
506  // If the temporary is a global and has a constant initializer or is a
507  // constant temporary that we promoted to a global, we may have already
508  // initialized it.
509  if (!Var->hasInitializer()) {
510  Var->setInitializer(CGM.EmitNullConstant(E->getType()));
511  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
512  }
513  } else {
514  switch (M->getStorageDuration()) {
515  case SD_Automatic:
516  if (auto *Size = EmitLifetimeStart(
517  CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
518  Alloca.getPointer())) {
519  pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker,
520  Alloca, Size);
521  }
522  break;
523 
524  case SD_FullExpression: {
525  if (!ShouldEmitLifetimeMarkers)
526  break;
527 
528  // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end
529  // marker. Instead, start the lifetime of a conditional temporary earlier
530  // so that it's unconditional. Don't do this with sanitizers which need
531  // more precise lifetime marks.
532  ConditionalEvaluation *OldConditional = nullptr;
533  CGBuilderTy::InsertPoint OldIP;
535  !SanOpts.has(SanitizerKind::HWAddress) &&
536  !SanOpts.has(SanitizerKind::Memory) &&
537  !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) {
538  OldConditional = OutermostConditional;
539  OutermostConditional = nullptr;
540 
541  OldIP = Builder.saveIP();
542  llvm::BasicBlock *Block = OldConditional->getStartingBlock();
543  Builder.restoreIP(CGBuilderTy::InsertPoint(
544  Block, llvm::BasicBlock::iterator(Block->back())));
545  }
546 
547  if (auto *Size = EmitLifetimeStart(
548  CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()),
549  Alloca.getPointer())) {
550  pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca,
551  Size);
552  }
553 
554  if (OldConditional) {
555  OutermostConditional = OldConditional;
556  Builder.restoreIP(OldIP);
557  }
558  break;
559  }
560 
561  default:
562  break;
563  }
564  EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true);
565  }
566  pushTemporaryCleanup(*this, M, E, Object);
567 
568  // Perform derived-to-base casts and/or field accesses, to get from the
569  // temporary object we created (and, potentially, for which we extended
570  // the lifetime) to the subobject we're binding the reference to.
571  for (SubobjectAdjustment &Adjustment : llvm::reverse(Adjustments)) {
572  switch (Adjustment.Kind) {
574  Object =
575  GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass,
576  Adjustment.DerivedToBase.BasePath->path_begin(),
577  Adjustment.DerivedToBase.BasePath->path_end(),
578  /*NullCheckValue=*/ false, E->getExprLoc());
579  break;
580 
583  LV = EmitLValueForField(LV, Adjustment.Field);
584  assert(LV.isSimple() &&
585  "materialized temporary field is not a simple lvalue");
586  Object = LV.getAddress(*this);
587  break;
588  }
589 
591  llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS);
592  Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr,
593  Adjustment.Ptr.MPT);
594  break;
595  }
596  }
597  }
598 
599  return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl);
600 }
601 
602 RValue
604  // Emit the expression as an lvalue.
605  LValue LV = EmitLValue(E);
606  assert(LV.isSimple());
607  llvm::Value *Value = LV.getPointer(*this);
608 
609  if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) {
610  // C++11 [dcl.ref]p5 (as amended by core issue 453):
611  // If a glvalue to which a reference is directly bound designates neither
612  // an existing object or function of an appropriate type nor a region of
613  // storage of suitable size and alignment to contain an object of the
614  // reference's type, the behavior is undefined.
615  QualType Ty = E->getType();
617  }
618 
619  return RValue::get(Value);
620 }
621 
622 
623 /// getAccessedFieldNo - Given an encoded value and a result number, return the
624 /// input field number being accessed.
626  const llvm::Constant *Elts) {
627  return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx))
628  ->getZExtValue();
629 }
630 
631 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h.
633  llvm::Value *High) {
634  llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL);
635  llvm::Value *K47 = Builder.getInt64(47);
636  llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul);
637  llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0);
638  llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul);
639  llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0);
640  return Builder.CreateMul(B1, KMul);
641 }
642 
644  return TCK == TCK_DowncastPointer || TCK == TCK_Upcast ||
646 }
647 
649  CXXRecordDecl *RD = Ty->getAsCXXRecordDecl();
650  return (RD && RD->hasDefinition() && RD->isDynamicClass()) &&
651  (TCK == TCK_MemberAccess || TCK == TCK_MemberCall ||
652  TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference ||
654 }
655 
657  return SanOpts.has(SanitizerKind::Null) ||
658  SanOpts.has(SanitizerKind::Alignment) ||
659  SanOpts.has(SanitizerKind::ObjectSize) ||
660  SanOpts.has(SanitizerKind::Vptr);
661 }
662 
664  llvm::Value *Ptr, QualType Ty,
665  CharUnits Alignment,
666  SanitizerSet SkippedChecks,
667  llvm::Value *ArraySize) {
669  return;
670 
671  // Don't check pointers outside the default address space. The null check
672  // isn't correct, the object-size check isn't supported by LLVM, and we can't
673  // communicate the addresses to the runtime handler for the vptr check.
674  if (Ptr->getType()->getPointerAddressSpace())
675  return;
676 
677  // Don't check pointers to volatile data. The behavior here is implementation-
678  // defined.
679  if (Ty.isVolatileQualified())
680  return;
681 
682  SanitizerScope SanScope(this);
683 
685  llvm::BasicBlock *Done = nullptr;
686 
687  // Quickly determine whether we have a pointer to an alloca. It's possible
688  // to skip null checks, and some alignment checks, for these pointers. This
689  // can reduce compile-time significantly.
690  auto PtrToAlloca = dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCasts());
691 
692  llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext());
693  llvm::Value *IsNonNull = nullptr;
694  bool IsGuaranteedNonNull =
695  SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca;
696  bool AllowNullPointers = isNullPointerAllowed(TCK);
697  if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) &&
698  !IsGuaranteedNonNull) {
699  // The glvalue must not be an empty glvalue.
700  IsNonNull = Builder.CreateIsNotNull(Ptr);
701 
702  // The IR builder can constant-fold the null check if the pointer points to
703  // a constant.
704  IsGuaranteedNonNull = IsNonNull == True;
705 
706  // Skip the null check if the pointer is known to be non-null.
707  if (!IsGuaranteedNonNull) {
708  if (AllowNullPointers) {
709  // When performing pointer casts, it's OK if the value is null.
710  // Skip the remaining checks in that case.
711  Done = createBasicBlock("null");
712  llvm::BasicBlock *Rest = createBasicBlock("not.null");
713  Builder.CreateCondBr(IsNonNull, Rest, Done);
714  EmitBlock(Rest);
715  } else {
716  Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null));
717  }
718  }
719  }
720 
721  if (SanOpts.has(SanitizerKind::ObjectSize) &&
722  !SkippedChecks.has(SanitizerKind::ObjectSize) &&
723  !Ty->isIncompleteType()) {
724  uint64_t TySize = CGM.getMinimumObjectSize(Ty).getQuantity();
725  llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize);
726  if (ArraySize)
727  Size = Builder.CreateMul(Size, ArraySize);
728 
729  // Degenerate case: new X[0] does not need an objectsize check.
730  llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size);
731  if (!ConstantSize || !ConstantSize->isNullValue()) {
732  // The glvalue must refer to a large enough storage region.
733  // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation
734  // to check this.
735  // FIXME: Get object address space
736  llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy };
737  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys);
738  llvm::Value *Min = Builder.getFalse();
739  llvm::Value *NullIsUnknown = Builder.getFalse();
740  llvm::Value *Dynamic = Builder.getFalse();
741  llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy);
742  llvm::Value *LargeEnough = Builder.CreateICmpUGE(
743  Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown, Dynamic}), Size);
744  Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize));
745  }
746  }
747 
748  uint64_t AlignVal = 0;
749  llvm::Value *PtrAsInt = nullptr;
750 
751  if (SanOpts.has(SanitizerKind::Alignment) &&
752  !SkippedChecks.has(SanitizerKind::Alignment)) {
753  AlignVal = Alignment.getQuantity();
754  if (!Ty->isIncompleteType() && !AlignVal)
755  AlignVal = CGM.getNaturalTypeAlignment(Ty, nullptr, nullptr,
756  /*ForPointeeType=*/true)
757  .getQuantity();
758 
759  // The glvalue must be suitably aligned.
760  if (AlignVal > 1 &&
761  (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) {
762  PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy);
763  llvm::Value *Align = Builder.CreateAnd(
764  PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1));
765  llvm::Value *Aligned =
766  Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0));
767  if (Aligned != True)
768  Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment));
769  }
770  }
771 
772  if (Checks.size() > 0) {
773  // Make sure we're not losing information. Alignment needs to be a power of
774  // 2
775  assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal);
776  llvm::Constant *StaticData[] = {
778  llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1),
779  llvm::ConstantInt::get(Int8Ty, TCK)};
780  EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData,
781  PtrAsInt ? PtrAsInt : Ptr);
782  }
783 
784  // If possible, check that the vptr indicates that there is a subobject of
785  // type Ty at offset zero within this object.
786  //
787  // C++11 [basic.life]p5,6:
788  // [For storage which does not refer to an object within its lifetime]
789  // The program has undefined behavior if:
790  // -- the [pointer or glvalue] is used to access a non-static data member
791  // or call a non-static member function
792  if (SanOpts.has(SanitizerKind::Vptr) &&
793  !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) {
794  // Ensure that the pointer is non-null before loading it. If there is no
795  // compile-time guarantee, reuse the run-time null check or emit a new one.
796  if (!IsGuaranteedNonNull) {
797  if (!IsNonNull)
798  IsNonNull = Builder.CreateIsNotNull(Ptr);
799  if (!Done)
800  Done = createBasicBlock("vptr.null");
801  llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null");
802  Builder.CreateCondBr(IsNonNull, VptrNotNull, Done);
803  EmitBlock(VptrNotNull);
804  }
805 
806  // Compute a hash of the mangled name of the type.
807  //
808  // FIXME: This is not guaranteed to be deterministic! Move to a
809  // fingerprinting mechanism once LLVM provides one. For the time
810  // being the implementation happens to be deterministic.
811  SmallString<64> MangledName;
812  llvm::raw_svector_ostream Out(MangledName);
814  Out);
815 
816  // Contained in NoSanitizeList based on the mangled type.
817  if (!CGM.getContext().getNoSanitizeList().containsType(SanitizerKind::Vptr,
818  Out.str())) {
819  llvm::hash_code TypeHash = hash_value(Out.str());
820 
821  // Load the vptr, and compute hash_16_bytes(TypeHash, vptr).
822  llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash);
823  llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0);
824  Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign());
825  llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr);
826  llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty);
827 
828  llvm::Value *Hash = emitHash16Bytes(Builder, Low, High);
829  Hash = Builder.CreateTrunc(Hash, IntPtrTy);
830 
831  // Look the hash up in our cache.
832  const int CacheSize = 128;
833  llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize);
835  "__ubsan_vptr_type_cache");
836  llvm::Value *Slot = Builder.CreateAnd(Hash,
837  llvm::ConstantInt::get(IntPtrTy,
838  CacheSize-1));
839  llvm::Value *Indices[] = { Builder.getInt32(0), Slot };
841  IntPtrTy, Builder.CreateInBoundsGEP(HashTable, Cache, Indices),
842  getPointerAlign());
843 
844  // If the hash isn't in the cache, call a runtime handler to perform the
845  // hard work of checking whether the vptr is for an object of the right
846  // type. This will either fill in the cache and return, or produce a
847  // diagnostic.
848  llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash);
849  llvm::Constant *StaticData[] = {
853  llvm::ConstantInt::get(Int8Ty, TCK)
854  };
855  llvm::Value *DynamicData[] = { Ptr, Hash };
856  EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr),
857  SanitizerHandler::DynamicTypeCacheMiss, StaticData,
858  DynamicData);
859  }
860  }
861 
862  if (Done) {
863  Builder.CreateBr(Done);
864  EmitBlock(Done);
865  }
866 }
867 
868 /// Determine whether this expression refers to a flexible array member in a
869 /// struct. We disable array bounds checks for such members.
870 static bool isFlexibleArrayMemberExpr(const Expr *E) {
871  // For compatibility with existing code, we treat arrays of length 0 or
872  // 1 as flexible array members.
873  // FIXME: This is inconsistent with the warning code in SemaChecking. Unify
874  // the two mechanisms.
875  const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe();
876  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) {
877  // FIXME: Sema doesn't treat [1] as a flexible array member if the bound
878  // was produced by macro expansion.
879  if (CAT->getSize().ugt(1))
880  return false;
881  } else if (!isa<IncompleteArrayType>(AT))
882  return false;
883 
884  E = E->IgnoreParens();
885 
886  // A flexible array member must be the last member in the class.
887  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
888  // FIXME: If the base type of the member expr is not FD->getParent(),
889  // this should not be treated as a flexible array member access.
890  if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) {
891  // FIXME: Sema doesn't treat a T[1] union member as a flexible array
892  // member, only a T[0] or T[] member gets that treatment.
893  if (FD->getParent()->isUnion())
894  return true;
896  DeclContext::decl_iterator(const_cast<FieldDecl *>(FD)));
897  return ++FI == FD->getParent()->field_end();
898  }
899  } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) {
900  return IRE->getDecl()->getNextIvar() == nullptr;
901  }
902 
903  return false;
904 }
905 
907  QualType EltTy) {
908  ASTContext &C = getContext();
909  uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity();
910  if (!EltSize)
911  return nullptr;
912 
913  auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts());
914  if (!ArrayDeclRef)
915  return nullptr;
916 
917  auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl());
918  if (!ParamDecl)
919  return nullptr;
920 
921  auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>();
922  if (!POSAttr)
923  return nullptr;
924 
925  // Don't load the size if it's a lower bound.
926  int POSType = POSAttr->getType();
927  if (POSType != 0 && POSType != 1)
928  return nullptr;
929 
930  // Find the implicit size parameter.
931  auto PassedSizeIt = SizeArguments.find(ParamDecl);
932  if (PassedSizeIt == SizeArguments.end())
933  return nullptr;
934 
935  const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second;
936  assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable");
937  Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second;
938  llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false,
939  C.getSizeType(), E->getExprLoc());
940  llvm::Value *SizeOfElement =
941  llvm::ConstantInt::get(SizeInBytes->getType(), EltSize);
942  return Builder.CreateUDiv(SizeInBytes, SizeOfElement);
943 }
944 
945 /// If Base is known to point to the start of an array, return the length of
946 /// that array. Return 0 if the length cannot be determined.
948  CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) {
949  // For the vector indexing extension, the bound is the number of elements.
950  if (const VectorType *VT = Base->getType()->getAs<VectorType>()) {
951  IndexedType = Base->getType();
952  return CGF.Builder.getInt32(VT->getNumElements());
953  }
954 
955  Base = Base->IgnoreParens();
956 
957  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
958  if (CE->getCastKind() == CK_ArrayToPointerDecay &&
959  !isFlexibleArrayMemberExpr(CE->getSubExpr())) {
960  IndexedType = CE->getSubExpr()->getType();
961  const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe();
962  if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
963  return CGF.Builder.getInt(CAT->getSize());
964  else if (const auto *VAT = dyn_cast<VariableArrayType>(AT))
965  return CGF.getVLASize(VAT).NumElts;
966  // Ignore pass_object_size here. It's not applicable on decayed pointers.
967  }
968  }
969 
970  QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0};
971  if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) {
972  IndexedType = Base->getType();
973  return POS;
974  }
975 
976  return nullptr;
977 }
978 
980  llvm::Value *Index, QualType IndexType,
981  bool Accessed) {
982  assert(SanOpts.has(SanitizerKind::ArrayBounds) &&
983  "should not be called unless adding bounds checks");
984  SanitizerScope SanScope(this);
985 
986  QualType IndexedType;
987  llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType);
988  if (!Bound)
989  return;
990 
991  bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType();
992  llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned);
993  llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false);
994 
995  llvm::Constant *StaticData[] = {
997  EmitCheckTypeDescriptor(IndexedType),
998  EmitCheckTypeDescriptor(IndexType)
999  };
1000  llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal)
1001  : Builder.CreateICmpULE(IndexVal, BoundVal);
1002  EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds),
1003  SanitizerHandler::OutOfBounds, StaticData, Index);
1004 }
1005 
1006 
1009  bool isInc, bool isPre) {
1010  ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc());
1011 
1012  llvm::Value *NextVal;
1013  if (isa<llvm::IntegerType>(InVal.first->getType())) {
1014  uint64_t AmountVal = isInc ? 1 : -1;
1015  NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true);
1016 
1017  // Add the inc/dec to the real part.
1018  NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1019  } else {
1020  QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType();
1021  llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1);
1022  if (!isInc)
1023  FVal.changeSign();
1024  NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal);
1025 
1026  // Add the inc/dec to the real part.
1027  NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec");
1028  }
1029 
1030  ComplexPairTy IncVal(NextVal, InVal.second);
1031 
1032  // Store the updated result through the lvalue.
1033  EmitStoreOfComplex(IncVal, LV, /*init*/ false);
1034  if (getLangOpts().OpenMP)
1036  E->getSubExpr());
1037 
1038  // If this is a postinc, return the value read from memory, otherwise use the
1039  // updated value.
1040  return isPre ? IncVal : InVal;
1041 }
1042 
1044  CodeGenFunction *CGF) {
1045  // Bind VLAs in the cast type.
1046  if (CGF && E->getType()->isVariablyModifiedType())
1047  CGF->EmitVariablyModifiedType(E->getType());
1048 
1049  if (CGDebugInfo *DI = getModuleDebugInfo())
1050  DI->EmitExplicitCastType(E->getType());
1051 }
1052 
1053 //===----------------------------------------------------------------------===//
1054 // LValue Expression Emission
1055 //===----------------------------------------------------------------------===//
1056 
1057 /// EmitPointerWithAlignment - Given an expression of pointer type, try to
1058 /// derive a more accurate bound on the alignment of the pointer.
1060  LValueBaseInfo *BaseInfo,
1061  TBAAAccessInfo *TBAAInfo) {
1062  // We allow this with ObjC object pointers because of fragile ABIs.
1063  assert(E->getType()->isPointerType() ||
1065  E = E->IgnoreParens();
1066 
1067  // Casts:
1068  if (const CastExpr *CE = dyn_cast<CastExpr>(E)) {
1069  if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE))
1070  CGM.EmitExplicitCastExprType(ECE, this);
1071 
1072  switch (CE->getCastKind()) {
1073  // Non-converting casts (but not C's implicit conversion from void*).
1074  case CK_BitCast:
1075  case CK_NoOp:
1076  case CK_AddressSpaceConversion:
1077  if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) {
1078  if (PtrTy->getPointeeType()->isVoidType())
1079  break;
1080 
1081  LValueBaseInfo InnerBaseInfo;
1082  TBAAAccessInfo InnerTBAAInfo;
1083  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(),
1084  &InnerBaseInfo,
1085  &InnerTBAAInfo);
1086  if (BaseInfo) *BaseInfo = InnerBaseInfo;
1087  if (TBAAInfo) *TBAAInfo = InnerTBAAInfo;
1088 
1089  if (isa<ExplicitCastExpr>(CE)) {
1090  LValueBaseInfo TargetTypeBaseInfo;
1091  TBAAAccessInfo TargetTypeTBAAInfo;
1093  E->getType(), &TargetTypeBaseInfo, &TargetTypeTBAAInfo);
1094  if (TBAAInfo)
1095  *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo,
1096  TargetTypeTBAAInfo);
1097  // If the source l-value is opaque, honor the alignment of the
1098  // casted-to type.
1099  if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) {
1100  if (BaseInfo)
1101  BaseInfo->mergeForCast(TargetTypeBaseInfo);
1102  Addr = Address(Addr.getPointer(), Addr.getElementType(), Align);
1103  }
1104  }
1105 
1106  if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) &&
1107  CE->getCastKind() == CK_BitCast) {
1108  if (auto PT = E->getType()->getAs<PointerType>())
1109  EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(),
1110  /*MayBeNull=*/true,
1112  CE->getBeginLoc());
1113  }
1114 
1115  if (CE->getCastKind() == CK_AddressSpaceConversion)
1116  return Builder.CreateAddrSpaceCast(Addr, ConvertType(E->getType()));
1117 
1118  llvm::Type *ElemTy = ConvertTypeForMem(E->getType()->getPointeeType());
1119  return Builder.CreateElementBitCast(Addr, ElemTy);
1120  }
1121  break;
1122 
1123  // Array-to-pointer decay.
1124  case CK_ArrayToPointerDecay:
1125  return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo);
1126 
1127  // Derived-to-base conversions.
1128  case CK_UncheckedDerivedToBase:
1129  case CK_DerivedToBase: {
1130  // TODO: Support accesses to members of base classes in TBAA. For now, we
1131  // conservatively pretend that the complete object is of the base class
1132  // type.
1133  if (TBAAInfo)
1134  *TBAAInfo = CGM.getTBAAAccessInfo(E->getType());
1135  Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo);
1136  auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl();
1137  return GetAddressOfBaseClass(Addr, Derived,
1138  CE->path_begin(), CE->path_end(),
1140  CE->getExprLoc());
1141  }
1142 
1143  // TODO: Is there any reason to treat base-to-derived conversions
1144  // specially?
1145  default:
1146  break;
1147  }
1148  }
1149 
1150  // Unary &.
1151  if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1152  if (UO->getOpcode() == UO_AddrOf) {
1153  LValue LV = EmitLValue(UO->getSubExpr());
1154  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
1155  if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo();
1156  return LV.getAddress(*this);
1157  }
1158  }
1159 
1160  // TODO: conditional operators, comma.
1161 
1162  // Otherwise, use the alignment of the type.
1163  CharUnits Align =
1164  CGM.getNaturalPointeeTypeAlignment(E->getType(), BaseInfo, TBAAInfo);
1165  llvm::Type *ElemTy = ConvertTypeForMem(E->getType()->getPointeeType());
1166  return Address(EmitScalarExpr(E), ElemTy, Align);
1167 }
1168 
1170  llvm::Value *V = RV.getScalarVal();
1171  if (auto MPT = T->getAs<MemberPointerType>())
1172  return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, V, MPT);
1173  return Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType()));
1174 }
1175 
1177  if (Ty->isVoidType())
1178  return RValue::get(nullptr);
1179 
1180  switch (getEvaluationKind(Ty)) {
1181  case TEK_Complex: {
1182  llvm::Type *EltTy =
1184  llvm::Value *U = llvm::UndefValue::get(EltTy);
1185  return RValue::getComplex(std::make_pair(U, U));
1186  }
1187 
1188  // If this is a use of an undefined aggregate type, the aggregate must have an
1189  // identifiable address. Just because the contents of the value are undefined
1190  // doesn't mean that the address can't be taken and compared.
1191  case TEK_Aggregate: {
1192  Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp");
1193  return RValue::getAggregate(DestPtr);
1194  }
1195 
1196  case TEK_Scalar:
1197  return RValue::get(llvm::UndefValue::get(ConvertType(Ty)));
1198  }
1199  llvm_unreachable("bad evaluation kind");
1200 }
1201 
1203  const char *Name) {
1204  ErrorUnsupported(E, Name);
1205  return GetUndefRValue(E->getType());
1206 }
1207 
1209  const char *Name) {
1210  ErrorUnsupported(E, Name);
1211  llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
1212  return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()),
1213  E->getType());
1214 }
1215 
1217  const Expr *Base = Obj;
1218  while (!isa<CXXThisExpr>(Base)) {
1219  // The result of a dynamic_cast can be null.
1220  if (isa<CXXDynamicCastExpr>(Base))
1221  return false;
1222 
1223  if (const auto *CE = dyn_cast<CastExpr>(Base)) {
1224  Base = CE->getSubExpr();
1225  } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) {
1226  Base = PE->getSubExpr();
1227  } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) {
1228  if (UO->getOpcode() == UO_Extension)
1229  Base = UO->getSubExpr();
1230  else
1231  return false;
1232  } else {
1233  return false;
1234  }
1235  }
1236  return true;
1237 }
1238 
1240  LValue LV;
1241  if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E))
1242  LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true);
1243  else
1244  LV = EmitLValue(E);
1245  if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) {
1246  SanitizerSet SkippedChecks;
1247  if (const auto *ME = dyn_cast<MemberExpr>(E)) {
1248  bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase());
1249  if (IsBaseCXXThis)
1250  SkippedChecks.set(SanitizerKind::Alignment, true);
1251  if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase()))
1252  SkippedChecks.set(SanitizerKind::Null, true);
1253  }
1254  EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(*this), E->getType(),
1255  LV.getAlignment(), SkippedChecks);
1256  }
1257  return LV;
1258 }
1259 
1260 /// EmitLValue - Emit code to compute a designator that specifies the location
1261 /// of the expression.
1262 ///
1263 /// This can return one of two things: a simple address or a bitfield reference.
1264 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be
1265 /// an LLVM pointer type.
1266 ///
1267 /// If this returns a bitfield reference, nothing about the pointee type of the
1268 /// LLVM value is known: For example, it may not be a pointer to an integer.
1269 ///
1270 /// If this returns a normal address, and if the lvalue's C type is fixed size,
1271 /// this method guarantees that the returned pointer type will point to an LLVM
1272 /// type of the same size of the lvalue's type. If the lvalue has a variable
1273 /// length type, this is not possible.
1274 ///
1276  ApplyDebugLocation DL(*this, E);
1277  switch (E->getStmtClass()) {
1278  default: return EmitUnsupportedLValue(E, "l-value expression");
1279 
1280  case Expr::ObjCPropertyRefExprClass:
1281  llvm_unreachable("cannot emit a property reference directly");
1282 
1283  case Expr::ObjCSelectorExprClass:
1284  return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E));
1285  case Expr::ObjCIsaExprClass:
1286  return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E));
1287  case Expr::BinaryOperatorClass:
1288  return EmitBinaryOperatorLValue(cast<BinaryOperator>(E));
1289  case Expr::CompoundAssignOperatorClass: {
1290  QualType Ty = E->getType();
1291  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1292  Ty = AT->getValueType();
1293  if (!Ty->isAnyComplexType())
1294  return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1295  return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E));
1296  }
1297  case Expr::CallExprClass:
1298  case Expr::CXXMemberCallExprClass:
1299  case Expr::CXXOperatorCallExprClass:
1300  case Expr::UserDefinedLiteralClass:
1301  return EmitCallExprLValue(cast<CallExpr>(E));
1302  case Expr::CXXRewrittenBinaryOperatorClass:
1303  return EmitLValue(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm());
1304  case Expr::VAArgExprClass:
1305  return EmitVAArgExprLValue(cast<VAArgExpr>(E));
1306  case Expr::DeclRefExprClass:
1307  return EmitDeclRefLValue(cast<DeclRefExpr>(E));
1308  case Expr::ConstantExprClass: {
1309  const ConstantExpr *CE = cast<ConstantExpr>(E);
1310  if (llvm::Value *Result = ConstantEmitter(*this).tryEmitConstantExpr(CE)) {
1311  QualType RetType = cast<CallExpr>(CE->getSubExpr()->IgnoreImplicit())
1312  ->getCallReturnType(getContext())
1313  ->getPointeeType();
1314  return MakeNaturalAlignAddrLValue(Result, RetType);
1315  }
1316  return EmitLValue(cast<ConstantExpr>(E)->getSubExpr());
1317  }
1318  case Expr::ParenExprClass:
1319  return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
1320  case Expr::GenericSelectionExprClass:
1321  return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr());
1322  case Expr::PredefinedExprClass:
1323  return EmitPredefinedLValue(cast<PredefinedExpr>(E));
1324  case Expr::StringLiteralClass:
1325  return EmitStringLiteralLValue(cast<StringLiteral>(E));
1326  case Expr::ObjCEncodeExprClass:
1327  return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E));
1328  case Expr::PseudoObjectExprClass:
1329  return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E));
1330  case Expr::InitListExprClass:
1331  return EmitInitListLValue(cast<InitListExpr>(E));
1332  case Expr::CXXTemporaryObjectExprClass:
1333  case Expr::CXXConstructExprClass:
1334  return EmitCXXConstructLValue(cast<CXXConstructExpr>(E));
1335  case Expr::CXXBindTemporaryExprClass:
1336  return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E));
1337  case Expr::CXXUuidofExprClass:
1338  return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E));
1339  case Expr::LambdaExprClass:
1340  return EmitAggExprToLValue(E);
1341 
1342  case Expr::ExprWithCleanupsClass: {
1343  const auto *cleanups = cast<ExprWithCleanups>(E);
1344  RunCleanupsScope Scope(*this);
1345  LValue LV = EmitLValue(cleanups->getSubExpr());
1346  if (LV.isSimple()) {
1347  // Defend against branches out of gnu statement expressions surrounded by
1348  // cleanups.
1349  Address Addr = LV.getAddress(*this);
1350  llvm::Value *V = Addr.getPointer();
1351  Scope.ForceCleanup({&V});
1352  return LValue::MakeAddr(Addr.withPointer(V), LV.getType(), getContext(),
1353  LV.getBaseInfo(), LV.getTBAAInfo());
1354  }
1355  // FIXME: Is it possible to create an ExprWithCleanups that produces a
1356  // bitfield lvalue or some other non-simple lvalue?
1357  return LV;
1358  }
1359 
1360  case Expr::CXXDefaultArgExprClass: {
1361  auto *DAE = cast<CXXDefaultArgExpr>(E);
1362  CXXDefaultArgExprScope Scope(*this, DAE);
1363  return EmitLValue(DAE->getExpr());
1364  }
1365  case Expr::CXXDefaultInitExprClass: {
1366  auto *DIE = cast<CXXDefaultInitExpr>(E);
1367  CXXDefaultInitExprScope Scope(*this, DIE);
1368  return EmitLValue(DIE->getExpr());
1369  }
1370  case Expr::CXXTypeidExprClass:
1371  return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E));
1372 
1373  case Expr::ObjCMessageExprClass:
1374  return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E));
1375  case Expr::ObjCIvarRefExprClass:
1376  return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E));
1377  case Expr::StmtExprClass:
1378  return EmitStmtExprLValue(cast<StmtExpr>(E));
1379  case Expr::UnaryOperatorClass:
1380  return EmitUnaryOpLValue(cast<UnaryOperator>(E));
1381  case Expr::ArraySubscriptExprClass:
1382  return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E));
1383  case Expr::MatrixSubscriptExprClass:
1384  return EmitMatrixSubscriptExpr(cast<MatrixSubscriptExpr>(E));
1385  case Expr::OMPArraySectionExprClass:
1386  return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E));
1387  case Expr::ExtVectorElementExprClass:
1388  return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E));
1389  case Expr::MemberExprClass:
1390  return EmitMemberExpr(cast<MemberExpr>(E));
1391  case Expr::CompoundLiteralExprClass:
1392  return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E));
1393  case Expr::ConditionalOperatorClass:
1394  return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E));
1395  case Expr::BinaryConditionalOperatorClass:
1396  return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E));
1397  case Expr::ChooseExprClass:
1398  return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr());
1399  case Expr::OpaqueValueExprClass:
1400  return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E));
1401  case Expr::SubstNonTypeTemplateParmExprClass:
1402  return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement());
1403  case Expr::ImplicitCastExprClass:
1404  case Expr::CStyleCastExprClass:
1405  case Expr::CXXFunctionalCastExprClass:
1406  case Expr::CXXStaticCastExprClass:
1407  case Expr::CXXDynamicCastExprClass:
1408  case Expr::CXXReinterpretCastExprClass:
1409  case Expr::CXXConstCastExprClass:
1410  case Expr::CXXAddrspaceCastExprClass:
1411  case Expr::ObjCBridgedCastExprClass:
1412  return EmitCastLValue(cast<CastExpr>(E));
1413 
1414  case Expr::MaterializeTemporaryExprClass:
1415  return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E));
1416 
1417  case Expr::CoawaitExprClass:
1418  return EmitCoawaitLValue(cast<CoawaitExpr>(E));
1419  case Expr::CoyieldExprClass:
1420  return EmitCoyieldLValue(cast<CoyieldExpr>(E));
1421  }
1422 }
1423 
1424 /// Given an object of the given canonical type, can we safely copy a
1425 /// value out of it based on its initializer?
1427  assert(type.isCanonical());
1428  assert(!type->isReferenceType());
1429 
1430  // Must be const-qualified but non-volatile.
1431  Qualifiers qs = type.getLocalQualifiers();
1432  if (!qs.hasConst() || qs.hasVolatile()) return false;
1433 
1434  // Otherwise, all object types satisfy this except C++ classes with
1435  // mutable subobjects or non-trivial copy/destroy behavior.
1436  if (const auto *RT = dyn_cast<RecordType>(type))
1437  if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()))
1438  if (RD->hasMutableFields() || !RD->isTrivial())
1439  return false;
1440 
1441  return true;
1442 }
1443 
1444 /// Can we constant-emit a load of a reference to a variable of the
1445 /// given type? This is different from predicates like
1446 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply
1447 /// in situations that don't necessarily satisfy the language's rules
1448 /// for this (e.g. C++'s ODR-use rules). For example, we want to able
1449 /// to do this with const float variables even if those variables
1450 /// aren't marked 'constexpr'.
1456 };
1458  type = type.getCanonicalType();
1459  if (const auto *ref = dyn_cast<ReferenceType>(type)) {
1460  if (isConstantEmittableObjectType(ref->getPointeeType()))
1461  return CEK_AsValueOrReference;
1462  return CEK_AsReferenceOnly;
1463  }
1465  return CEK_AsValueOnly;
1466  return CEK_None;
1467 }
1468 
1469 /// Try to emit a reference to the given value without producing it as
1470 /// an l-value. This is just an optimization, but it avoids us needing
1471 /// to emit global copies of variables if they're named without triggering
1472 /// a formal use in a context where we can't emit a direct reference to them,
1473 /// for instance if a block or lambda or a member of a local class uses a
1474 /// const int variable or constexpr variable from an enclosing function.
1477  ValueDecl *value = refExpr->getDecl();
1478 
1479  // The value needs to be an enum constant or a constant variable.
1481  if (isa<ParmVarDecl>(value)) {
1482  CEK = CEK_None;
1483  } else if (auto *var = dyn_cast<VarDecl>(value)) {
1484  CEK = checkVarTypeForConstantEmission(var->getType());
1485  } else if (isa<EnumConstantDecl>(value)) {
1486  CEK = CEK_AsValueOnly;
1487  } else {
1488  CEK = CEK_None;
1489  }
1490  if (CEK == CEK_None) return ConstantEmission();
1491 
1492  Expr::EvalResult result;
1493  bool resultIsReference;
1494  QualType resultType;
1495 
1496  // It's best to evaluate all the way as an r-value if that's permitted.
1497  if (CEK != CEK_AsReferenceOnly &&
1498  refExpr->EvaluateAsRValue(result, getContext())) {
1499  resultIsReference = false;
1500  resultType = refExpr->getType();
1501 
1502  // Otherwise, try to evaluate as an l-value.
1503  } else if (CEK != CEK_AsValueOnly &&
1504  refExpr->EvaluateAsLValue(result, getContext())) {
1505  resultIsReference = true;
1506  resultType = value->getType();
1507 
1508  // Failure.
1509  } else {
1510  return ConstantEmission();
1511  }
1512 
1513  // In any case, if the initializer has side-effects, abandon ship.
1514  if (result.HasSideEffects)
1515  return ConstantEmission();
1516 
1517  // In CUDA/HIP device compilation, a lambda may capture a reference variable
1518  // referencing a global host variable by copy. In this case the lambda should
1519  // make a copy of the value of the global host variable. The DRE of the
1520  // captured reference variable cannot be emitted as load from the host
1521  // global variable as compile time constant, since the host variable is not
1522  // accessible on device. The DRE of the captured reference variable has to be
1523  // loaded from captures.
1524  if (CGM.getLangOpts().CUDAIsDevice && result.Val.isLValue() &&
1526  auto *MD = dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl);
1527  if (MD && MD->getParent()->isLambda() &&
1528  MD->getOverloadedOperator() == OO_Call) {
1529  const APValue::LValueBase &base = result.Val.getLValueBase();
1530  if (const ValueDecl *D = base.dyn_cast<const ValueDecl *>()) {
1531  if (const VarDecl *VD = dyn_cast<const VarDecl>(D)) {
1532  if (!VD->hasAttr<CUDADeviceAttr>()) {
1533  return ConstantEmission();
1534  }
1535  }
1536  }
1537  }
1538  }
1539 
1540  // Emit as a constant.
1541  auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(),
1542  result.Val, resultType);
1543 
1544  // Make sure we emit a debug reference to the global variable.
1545  // This should probably fire even for
1546  if (isa<VarDecl>(value)) {
1547  if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value)))
1548  EmitDeclRefExprDbgValue(refExpr, result.Val);
1549  } else {
1550  assert(isa<EnumConstantDecl>(value));
1551  EmitDeclRefExprDbgValue(refExpr, result.Val);
1552  }
1553 
1554  // If we emitted a reference constant, we need to dereference that.
1555  if (resultIsReference)
1557 
1558  return ConstantEmission::forValue(C);
1559 }
1560 
1562  const MemberExpr *ME) {
1563  if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) {
1564  // Try to emit static variable member expressions as DREs.
1565  return DeclRefExpr::Create(
1567  /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(),
1568  ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse());
1569  }
1570  return nullptr;
1571 }
1572 
1575  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME))
1576  return tryEmitAsConstant(DRE);
1577  return ConstantEmission();
1578 }
1579 
1581  const CodeGenFunction::ConstantEmission &Constant, Expr *E) {
1582  assert(Constant && "not a constant");
1583  if (Constant.isReference())
1584  return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E),
1585  E->getExprLoc())
1586  .getScalarVal();
1587  return Constant.getValue();
1588 }
1589 
1591  SourceLocation Loc) {
1592  return EmitLoadOfScalar(lvalue.getAddress(*this), lvalue.isVolatile(),
1593  lvalue.getType(), Loc, lvalue.getBaseInfo(),
1594  lvalue.getTBAAInfo(), lvalue.isNontemporal());
1595 }
1596 
1598  if (Ty->isBooleanType())
1599  return true;
1600 
1601  if (const EnumType *ET = Ty->getAs<EnumType>())
1602  return ET->getDecl()->getIntegerType()->isBooleanType();
1603 
1604  if (const AtomicType *AT = Ty->getAs<AtomicType>())
1605  return hasBooleanRepresentation(AT->getValueType());
1606 
1607  return false;
1608 }
1609 
1611  llvm::APInt &Min, llvm::APInt &End,
1612  bool StrictEnums, bool IsBool) {
1613  const EnumType *ET = Ty->getAs<EnumType>();
1614  bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums &&
1615  ET && !ET->getDecl()->isFixed();
1616  if (!IsBool && !IsRegularCPlusPlusEnum)
1617  return false;
1618 
1619  if (IsBool) {
1620  Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0);
1621  End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2);
1622  } else {
1623  const EnumDecl *ED = ET->getDecl();
1624  llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType());
1625  unsigned Bitwidth = LTy->getScalarSizeInBits();
1626  unsigned NumNegativeBits = ED->getNumNegativeBits();
1627  unsigned NumPositiveBits = ED->getNumPositiveBits();
1628 
1629  if (NumNegativeBits) {
1630  unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1);
1631  assert(NumBits <= Bitwidth);
1632  End = llvm::APInt(Bitwidth, 1) << (NumBits - 1);
1633  Min = -End;
1634  } else {
1635  assert(NumPositiveBits <= Bitwidth);
1636  End = llvm::APInt(Bitwidth, 1) << NumPositiveBits;
1637  Min = llvm::APInt::getZero(Bitwidth);
1638  }
1639  }
1640  return true;
1641 }
1642 
1643 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) {
1644  llvm::APInt Min, End;
1645  if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums,
1647  return nullptr;
1648 
1649  llvm::MDBuilder MDHelper(getLLVMContext());
1650  return MDHelper.createRange(Min, End);
1651 }
1652 
1654  SourceLocation Loc) {
1655  bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool);
1656  bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum);
1657  if (!HasBoolCheck && !HasEnumCheck)
1658  return false;
1659 
1660  bool IsBool = hasBooleanRepresentation(Ty) ||
1662  bool NeedsBoolCheck = HasBoolCheck && IsBool;
1663  bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>();
1664  if (!NeedsBoolCheck && !NeedsEnumCheck)
1665  return false;
1666 
1667  // Single-bit booleans don't need to be checked. Special-case this to avoid
1668  // a bit width mismatch when handling bitfield values. This is handled by
1669  // EmitFromMemory for the non-bitfield case.
1670  if (IsBool &&
1671  cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1)
1672  return false;
1673 
1674  llvm::APInt Min, End;
1675  if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool))
1676  return true;
1677 
1678  auto &Ctx = getLLVMContext();
1679  SanitizerScope SanScope(this);
1680  llvm::Value *Check;
1681  --End;
1682  if (!Min) {
1683  Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End));
1684  } else {
1685  llvm::Value *Upper =
1686  Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End));
1687  llvm::Value *Lower =
1688  Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min));
1689  Check = Builder.CreateAnd(Upper, Lower);
1690  }
1691  llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc),
1694  NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool;
1695  EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue,
1696  StaticArgs, EmitCheckValue(Value));
1697  return true;
1698 }
1699 
1701  QualType Ty,
1702  SourceLocation Loc,
1703  LValueBaseInfo BaseInfo,
1704  TBAAAccessInfo TBAAInfo,
1705  bool isNontemporal) {
1706  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1707  // For better performance, handle vector loads differently.
1708  if (Ty->isVectorType()) {
1709  const llvm::Type *EltTy = Addr.getElementType();
1710 
1711  const auto *VTy = cast<llvm::FixedVectorType>(EltTy);
1712 
1713  // Handle vectors of size 3 like size 4 for better performance.
1714  if (VTy->getNumElements() == 3) {
1715 
1716  // Bitcast to vec4 type.
1717  auto *vec4Ty = llvm::FixedVectorType::get(VTy->getElementType(), 4);
1718  Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4");
1719  // Now load value.
1720  llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4");
1721 
1722  // Shuffle vector to get vec3.
1723  V = Builder.CreateShuffleVector(V, ArrayRef<int>{0, 1, 2},
1724  "extractVec");
1725  return EmitFromMemory(V, Ty);
1726  }
1727  }
1728  }
1729 
1730  // Atomic operations have to be done on integral types.
1731  LValue AtomicLValue =
1732  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1733  if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) {
1734  return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal();
1735  }
1736 
1737  llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile);
1738  if (isNontemporal) {
1739  llvm::MDNode *Node = llvm::MDNode::get(
1740  Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1741  Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1742  }
1743 
1745 
1746  if (EmitScalarRangeCheck(Load, Ty, Loc)) {
1747  // In order to prevent the optimizer from throwing away the check, don't
1748  // attach range metadata to the load.
1749  } else if (CGM.getCodeGenOpts().OptimizationLevel > 0)
1750  if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty))
1751  Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo);
1752 
1753  return EmitFromMemory(Load, Ty);
1754 }
1755 
1757  // Bool has a different representation in memory than in registers.
1758  if (hasBooleanRepresentation(Ty)) {
1759  // This should really always be an i1, but sometimes it's already
1760  // an i8, and it's awkward to track those cases down.
1761  if (Value->getType()->isIntegerTy(1))
1762  return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool");
1763  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1764  "wrong value rep of bool");
1765  }
1766 
1767  return Value;
1768 }
1769 
1771  // Bool has a different representation in memory than in registers.
1772  if (hasBooleanRepresentation(Ty)) {
1773  assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) &&
1774  "wrong value rep of bool");
1775  return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool");
1776  }
1777 
1778  return Value;
1779 }
1780 
1781 // Convert the pointer of \p Addr to a pointer to a vector (the value type of
1782 // MatrixType), if it points to a array (the memory type of MatrixType).
1784  bool IsVector = true) {
1785  auto *ArrayTy = dyn_cast<llvm::ArrayType>(Addr.getElementType());
1786  if (ArrayTy && IsVector) {
1787  auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(),
1788  ArrayTy->getNumElements());
1789 
1790  return Address(CGF.Builder.CreateElementBitCast(Addr, VectorTy));
1791  }
1792  auto *VectorTy = dyn_cast<llvm::VectorType>(Addr.getElementType());
1793  if (VectorTy && !IsVector) {
1794  auto *ArrayTy = llvm::ArrayType::get(
1795  VectorTy->getElementType(),
1796  cast<llvm::FixedVectorType>(VectorTy)->getNumElements());
1797 
1798  return Address(CGF.Builder.CreateElementBitCast(Addr, ArrayTy));
1799  }
1800 
1801  return Addr;
1802 }
1803 
1804 // Emit a store of a matrix LValue. This may require casting the original
1805 // pointer to memory address (ArrayType) to a pointer to the value type
1806 // (VectorType).
1807 static void EmitStoreOfMatrixScalar(llvm::Value *value, LValue lvalue,
1808  bool isInit, CodeGenFunction &CGF) {
1809  Address Addr = MaybeConvertMatrixAddress(lvalue.getAddress(CGF), CGF,
1810  value->getType()->isVectorTy());
1811  CGF.EmitStoreOfScalar(value, Addr, lvalue.isVolatile(), lvalue.getType(),
1812  lvalue.getBaseInfo(), lvalue.getTBAAInfo(), isInit,
1813  lvalue.isNontemporal());
1814 }
1815 
1817  bool Volatile, QualType Ty,
1818  LValueBaseInfo BaseInfo,
1819  TBAAAccessInfo TBAAInfo,
1820  bool isInit, bool isNontemporal) {
1821  if (!CGM.getCodeGenOpts().PreserveVec3Type) {
1822  // Handle vectors differently to get better performance.
1823  if (Ty->isVectorType()) {
1824  llvm::Type *SrcTy = Value->getType();
1825  auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy);
1826  // Handle vec3 special.
1827  if (VecTy && cast<llvm::FixedVectorType>(VecTy)->getNumElements() == 3) {
1828  // Our source is a vec3, do a shuffle vector to make it a vec4.
1829  Value = Builder.CreateShuffleVector(Value, ArrayRef<int>{0, 1, 2, -1},
1830  "extractVec");
1831  SrcTy = llvm::FixedVectorType::get(VecTy->getElementType(), 4);
1832  }
1833  if (Addr.getElementType() != SrcTy) {
1834  Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp");
1835  }
1836  }
1837  }
1838 
1839  Value = EmitToMemory(Value, Ty);
1840 
1841  LValue AtomicLValue =
1842  LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo);
1843  if (Ty->isAtomicType() ||
1844  (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) {
1845  EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit);
1846  return;
1847  }
1848 
1849  llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
1850  if (isNontemporal) {
1851  llvm::MDNode *Node =
1852  llvm::MDNode::get(Store->getContext(),
1853  llvm::ConstantAsMetadata::get(Builder.getInt32(1)));
1854  Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node);
1855  }
1856 
1858 }
1859 
1861  bool isInit) {
1862  if (lvalue.getType()->isConstantMatrixType()) {
1863  EmitStoreOfMatrixScalar(value, lvalue, isInit, *this);
1864  return;
1865  }
1866 
1867  EmitStoreOfScalar(value, lvalue.getAddress(*this), lvalue.isVolatile(),
1868  lvalue.getType(), lvalue.getBaseInfo(),
1869  lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal());
1870 }
1871 
1872 // Emit a load of a LValue of matrix type. This may require casting the pointer
1873 // to memory address (ArrayType) to a pointer to the value type (VectorType).
1875  CodeGenFunction &CGF) {
1876  assert(LV.getType()->isConstantMatrixType());
1877  Address Addr = MaybeConvertMatrixAddress(LV.getAddress(CGF), CGF);
1878  LV.setAddress(Addr);
1879  return RValue::get(CGF.EmitLoadOfScalar(LV, Loc));
1880 }
1881 
1882 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
1883 /// method emits the address of the lvalue, then loads the result as an rvalue,
1884 /// returning the rvalue.
1886  if (LV.isObjCWeak()) {
1887  // load of a __weak object.
1888  Address AddrWeakObj = LV.getAddress(*this);
1890  AddrWeakObj));
1891  }
1893  // In MRC mode, we do a load+autorelease.
1894  if (!getLangOpts().ObjCAutoRefCount) {
1895  return RValue::get(EmitARCLoadWeak(LV.getAddress(*this)));
1896  }
1897 
1898  // In ARC mode, we load retained and then consume the value.
1899  llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress(*this));
1900  Object = EmitObjCConsumeObject(LV.getType(), Object);
1901  return RValue::get(Object);
1902  }
1903 
1904  if (LV.isSimple()) {
1905  assert(!LV.getType()->isFunctionType());
1906 
1907  if (LV.getType()->isConstantMatrixType())
1908  return EmitLoadOfMatrixLValue(LV, Loc, *this);
1909 
1910  // Everything needs a load.
1911  return RValue::get(EmitLoadOfScalar(LV, Loc));
1912  }
1913 
1914  if (LV.isVectorElt()) {
1915  llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(),
1916  LV.isVolatileQualified());
1917  return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(),
1918  "vecext"));
1919  }
1920 
1921  // If this is a reference to a subset of the elements of a vector, either
1922  // shuffle the input or extract/insert them as appropriate.
1923  if (LV.isExtVectorElt()) {
1925  }
1926 
1927  // Global Register variables always invoke intrinsics
1928  if (LV.isGlobalReg())
1929  return EmitLoadOfGlobalRegLValue(LV);
1930 
1931  if (LV.isMatrixElt()) {
1932  llvm::Value *Idx = LV.getMatrixIdx();
1933  if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
1934  const auto *const MatTy = LV.getType()->castAs<ConstantMatrixType>();
1935  llvm::MatrixBuilder<CGBuilderTy> MB(Builder);
1936  MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
1937  }
1938  llvm::LoadInst *Load =
1940  return RValue::get(Builder.CreateExtractElement(Load, Idx, "matrixext"));
1941  }
1942 
1943  assert(LV.isBitField() && "Unknown LValue type!");
1944  return EmitLoadOfBitfieldLValue(LV, Loc);
1945 }
1946 
1948  SourceLocation Loc) {
1949  const CGBitFieldInfo &Info = LV.getBitFieldInfo();
1950 
1951  // Get the output type.
1952  llvm::Type *ResLTy = ConvertType(LV.getType());
1953 
1954  Address Ptr = LV.getBitFieldAddress();
1955  llvm::Value *Val =
1956  Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load");
1957 
1958  bool UseVolatile = LV.isVolatileQualified() &&
1959  Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
1960  const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
1961  const unsigned StorageSize =
1962  UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
1963  if (Info.IsSigned) {
1964  assert(static_cast<unsigned>(Offset + Info.Size) <= StorageSize);
1965  unsigned HighBits = StorageSize - Offset - Info.Size;
1966  if (HighBits)
1967  Val = Builder.CreateShl(Val, HighBits, "bf.shl");
1968  if (Offset + HighBits)
1969  Val = Builder.CreateAShr(Val, Offset + HighBits, "bf.ashr");
1970  } else {
1971  if (Offset)
1972  Val = Builder.CreateLShr(Val, Offset, "bf.lshr");
1973  if (static_cast<unsigned>(Offset) + Info.Size < StorageSize)
1974  Val = Builder.CreateAnd(
1975  Val, llvm::APInt::getLowBitsSet(StorageSize, Info.Size), "bf.clear");
1976  }
1977  Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast");
1978  EmitScalarRangeCheck(Val, LV.getType(), Loc);
1979  return RValue::get(Val);
1980 }
1981 
1982 // If this is a reference to a subset of the elements of a vector, create an
1983 // appropriate shufflevector.
1986  LV.isVolatileQualified());
1987 
1988  const llvm::Constant *Elts = LV.getExtVectorElts();
1989 
1990  // If the result of the expression is a non-vector type, we must be extracting
1991  // a single element. Just codegen as an extractelement.
1992  const VectorType *ExprVT = LV.getType()->getAs<VectorType>();
1993  if (!ExprVT) {
1994  unsigned InIdx = getAccessedFieldNo(0, Elts);
1995  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
1996  return RValue::get(Builder.CreateExtractElement(Vec, Elt));
1997  }
1998 
1999  // Always use shuffle vector to try to retain the original program structure
2000  unsigned NumResultElts = ExprVT->getNumElements();
2001 
2002  SmallVector<int, 4> Mask;
2003  for (unsigned i = 0; i != NumResultElts; ++i)
2004  Mask.push_back(getAccessedFieldNo(i, Elts));
2005 
2006  Vec = Builder.CreateShuffleVector(Vec, Mask);
2007  return RValue::get(Vec);
2008 }
2009 
2010 /// Generates lvalue for partial ext_vector access.
2012  Address VectorAddress = LV.getExtVectorAddress();
2013  QualType EQT = LV.getType()->castAs<VectorType>()->getElementType();
2014  llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT);
2015 
2016  Address CastToPointerElement =
2017  Builder.CreateElementBitCast(VectorAddress, VectorElementTy,
2018  "conv.ptr.element");
2019 
2020  const llvm::Constant *Elts = LV.getExtVectorElts();
2021  unsigned ix = getAccessedFieldNo(0, Elts);
2022 
2023  Address VectorBasePtrPlusIx =
2024  Builder.CreateConstInBoundsGEP(CastToPointerElement, ix,
2025  "vector.elt");
2026 
2027  return VectorBasePtrPlusIx;
2028 }
2029 
2030 /// Load of global gamed gegisters are always calls to intrinsics.
2032  assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) &&
2033  "Bad type for register variable");
2034  llvm::MDNode *RegName = cast<llvm::MDNode>(
2035  cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata());
2036 
2037  // We accept integer and pointer types only
2038  llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType());
2039  llvm::Type *Ty = OrigTy;
2040  if (OrigTy->isPointerTy())
2041  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2042  llvm::Type *Types[] = { Ty };
2043 
2044  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types);
2045  llvm::Value *Call = Builder.CreateCall(
2046  F, llvm::MetadataAsValue::get(Ty->getContext(), RegName));
2047  if (OrigTy->isPointerTy())
2048  Call = Builder.CreateIntToPtr(Call, OrigTy);
2049  return RValue::get(Call);
2050 }
2051 
2052 /// EmitStoreThroughLValue - Store the specified rvalue into the specified
2053 /// lvalue, where both are guaranteed to the have the same type, and that type
2054 /// is 'Ty'.
2056  bool isInit) {
2057  if (!Dst.isSimple()) {
2058  if (Dst.isVectorElt()) {
2059  // Read/modify/write the vector, inserting the new element.
2061  Dst.isVolatileQualified());
2062  Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(),
2063  Dst.getVectorIdx(), "vecins");
2065  Dst.isVolatileQualified());
2066  return;
2067  }
2068 
2069  // If this is an update of extended vector elements, insert them as
2070  // appropriate.
2071  if (Dst.isExtVectorElt())
2073 
2074  if (Dst.isGlobalReg())
2075  return EmitStoreThroughGlobalRegLValue(Src, Dst);
2076 
2077  if (Dst.isMatrixElt()) {
2078  llvm::Value *Idx = Dst.getMatrixIdx();
2079  if (CGM.getCodeGenOpts().OptimizationLevel > 0) {
2080  const auto *const MatTy = Dst.getType()->castAs<ConstantMatrixType>();
2081  llvm::MatrixBuilder<CGBuilderTy> MB(Builder);
2082  MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened());
2083  }
2084  llvm::Instruction *Load = Builder.CreateLoad(Dst.getMatrixAddress());
2085  llvm::Value *Vec =
2086  Builder.CreateInsertElement(Load, Src.getScalarVal(), Idx, "matins");
2088  Dst.isVolatileQualified());
2089  return;
2090  }
2091 
2092  assert(Dst.isBitField() && "Unknown LValue type");
2093  return EmitStoreThroughBitfieldLValue(Src, Dst);
2094  }
2095 
2096  // There's special magic for assigning into an ARC-qualified l-value.
2097  if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) {
2098  switch (Lifetime) {
2099  case Qualifiers::OCL_None:
2100  llvm_unreachable("present but none");
2101 
2103  // nothing special
2104  break;
2105 
2107  if (isInit) {
2108  Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal()));
2109  break;
2110  }
2111  EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true);
2112  return;
2113 
2114  case Qualifiers::OCL_Weak:
2115  if (isInit)
2116  // Initialize and then skip the primitive store.
2117  EmitARCInitWeak(Dst.getAddress(*this), Src.getScalarVal());
2118  else
2119  EmitARCStoreWeak(Dst.getAddress(*this), Src.getScalarVal(),
2120  /*ignore*/ true);
2121  return;
2122 
2125  Src.getScalarVal()));
2126  // fall into the normal path
2127  break;
2128  }
2129  }
2130 
2131  if (Dst.isObjCWeak() && !Dst.isNonGC()) {
2132  // load of a __weak object.
2133  Address LvalueDst = Dst.getAddress(*this);
2134  llvm::Value *src = Src.getScalarVal();
2135  CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst);
2136  return;
2137  }
2138 
2139  if (Dst.isObjCStrong() && !Dst.isNonGC()) {
2140  // load of a __strong object.
2141  Address LvalueDst = Dst.getAddress(*this);
2142  llvm::Value *src = Src.getScalarVal();
2143  if (Dst.isObjCIvar()) {
2144  assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
2145  llvm::Type *ResultType = IntPtrTy;
2147  llvm::Value *RHS = dst.getPointer();
2148  RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
2149  llvm::Value *LHS =
2150  Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType,
2151  "sub.ptr.lhs.cast");
2152  llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
2153  CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst,
2154  BytesBetween);
2155  } else if (Dst.isGlobalObjCRef()) {
2156  CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst,
2157  Dst.isThreadLocalRef());
2158  }
2159  else
2160  CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst);
2161  return;
2162  }
2163 
2164  assert(Src.isScalar() && "Can't emit an agg store with this method");
2165  EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
2166 }
2167 
2169  llvm::Value **Result) {
2170  const CGBitFieldInfo &Info = Dst.getBitFieldInfo();
2171  llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType());
2172  Address Ptr = Dst.getBitFieldAddress();
2173 
2174  // Get the source value, truncated to the width of the bit-field.
2175  llvm::Value *SrcVal = Src.getScalarVal();
2176 
2177  // Cast the source to the storage type and shift it into place.
2178  SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(),
2179  /*isSigned=*/false);
2180  llvm::Value *MaskedVal = SrcVal;
2181 
2182  const bool UseVolatile =
2183  CGM.getCodeGenOpts().AAPCSBitfieldWidth && Dst.isVolatileQualified() &&
2184  Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget());
2185  const unsigned StorageSize =
2186  UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
2187  const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset;
2188  // See if there are other bits in the bitfield's storage we'll need to load
2189  // and mask together with source before storing.
2190  if (StorageSize != Info.Size) {
2191  assert(StorageSize > Info.Size && "Invalid bitfield size.");
2192  llvm::Value *Val =
2193  Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load");
2194 
2195  // Mask the source value as needed.
2196  if (!hasBooleanRepresentation(Dst.getType()))
2197  SrcVal = Builder.CreateAnd(
2198  SrcVal, llvm::APInt::getLowBitsSet(StorageSize, Info.Size),
2199  "bf.value");
2200  MaskedVal = SrcVal;
2201  if (Offset)
2202  SrcVal = Builder.CreateShl(SrcVal, Offset, "bf.shl");
2203 
2204  // Mask out the original value.
2205  Val = Builder.CreateAnd(
2206  Val, ~llvm::APInt::getBitsSet(StorageSize, Offset, Offset + Info.Size),
2207  "bf.clear");
2208 
2209  // Or together the unchanged values and the source value.
2210  SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set");
2211  } else {
2212  assert(Offset == 0);
2213  // According to the AACPS:
2214  // When a volatile bit-field is written, and its container does not overlap
2215  // with any non-bit-field member, its container must be read exactly once
2216  // and written exactly once using the access width appropriate to the type
2217  // of the container. The two accesses are not atomic.
2218  if (Dst.isVolatileQualified() && isAAPCS(CGM.getTarget()) &&
2219  CGM.getCodeGenOpts().ForceAAPCSBitfieldLoad)
2220  Builder.CreateLoad(Ptr, true, "bf.load");
2221  }
2222 
2223  // Write the new value back out.
2224  Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified());
2225 
2226  // Return the new value of the bit-field, if requested.
2227  if (Result) {
2228  llvm::Value *ResultVal = MaskedVal;
2229 
2230  // Sign extend the value if needed.
2231  if (Info.IsSigned) {
2232  assert(Info.Size <= StorageSize);
2233  unsigned HighBits = StorageSize - Info.Size;
2234  if (HighBits) {
2235  ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl");
2236  ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr");
2237  }
2238  }
2239 
2240  ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned,
2241  "bf.result.cast");
2242  *Result = EmitFromMemory(ResultVal, Dst.getType());
2243  }
2244 }
2245 
2247  LValue Dst) {
2248  // This access turns into a read/modify/write of the vector. Load the input
2249  // value now.
2251  Dst.isVolatileQualified());
2252  const llvm::Constant *Elts = Dst.getExtVectorElts();
2253 
2254  llvm::Value *SrcVal = Src.getScalarVal();
2255 
2256  if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) {
2257  unsigned NumSrcElts = VTy->getNumElements();
2258  unsigned NumDstElts =
2259  cast<llvm::FixedVectorType>(Vec->getType())->getNumElements();
2260  if (NumDstElts == NumSrcElts) {
2261  // Use shuffle vector is the src and destination are the same number of
2262  // elements and restore the vector mask since it is on the side it will be
2263  // stored.
2264  SmallVector<int, 4> Mask(NumDstElts);
2265  for (unsigned i = 0; i != NumSrcElts; ++i)
2266  Mask[getAccessedFieldNo(i, Elts)] = i;
2267 
2268  Vec = Builder.CreateShuffleVector(SrcVal, Mask);
2269  } else if (NumDstElts > NumSrcElts) {
2270  // Extended the source vector to the same length and then shuffle it
2271  // into the destination.
2272  // FIXME: since we're shuffling with undef, can we just use the indices
2273  // into that? This could be simpler.
2274  SmallVector<int, 4> ExtMask;
2275  for (unsigned i = 0; i != NumSrcElts; ++i)
2276  ExtMask.push_back(i);
2277  ExtMask.resize(NumDstElts, -1);
2278  llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal, ExtMask);
2279  // build identity
2280  SmallVector<int, 4> Mask;
2281  for (unsigned i = 0; i != NumDstElts; ++i)
2282  Mask.push_back(i);
2283 
2284  // When the vector size is odd and .odd or .hi is used, the last element
2285  // of the Elts constant array will be one past the size of the vector.
2286  // Ignore the last element here, if it is greater than the mask size.
2287  if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size())
2288  NumSrcElts--;
2289 
2290  // modify when what gets shuffled in
2291  for (unsigned i = 0; i != NumSrcElts; ++i)
2292  Mask[getAccessedFieldNo(i, Elts)] = i + NumDstElts;
2293  Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, Mask);
2294  } else {
2295  // We should never shorten the vector
2296  llvm_unreachable("unexpected shorten vector length");
2297  }
2298  } else {
2299  // If the Src is a scalar (not a vector) it must be updating one element.
2300  unsigned InIdx = getAccessedFieldNo(0, Elts);
2301  llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx);
2302  Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt);
2303  }
2304 
2306  Dst.isVolatileQualified());
2307 }
2308 
2309 /// Store of global named registers are always calls to intrinsics.
2311  assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) &&
2312  "Bad type for register variable");
2313  llvm::MDNode *RegName = cast<llvm::MDNode>(
2314  cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata());
2315  assert(RegName && "Register LValue is not metadata");
2316 
2317  // We accept integer and pointer types only
2318  llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType());
2319  llvm::Type *Ty = OrigTy;
2320  if (OrigTy->isPointerTy())
2321  Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy);
2322  llvm::Type *Types[] = { Ty };
2323 
2324  llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types);
2325  llvm::Value *Value = Src.getScalarVal();
2326  if (OrigTy->isPointerTy())
2327  Value = Builder.CreatePtrToInt(Value, Ty);
2328  Builder.CreateCall(
2329  F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value});
2330 }
2331 
2332 // setObjCGCLValueClass - sets class of the lvalue for the purpose of
2333 // generating write-barries API. It is currently a global, ivar,
2334 // or neither.
2335 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E,
2336  LValue &LV,
2337  bool IsMemberAccess=false) {
2338  if (Ctx.getLangOpts().getGC() == LangOptions::NonGC)
2339  return;
2340 
2341  if (isa<ObjCIvarRefExpr>(E)) {
2342  QualType ExpTy = E->getType();
2343  if (IsMemberAccess && ExpTy->isPointerType()) {
2344  // If ivar is a structure pointer, assigning to field of
2345  // this struct follows gcc's behavior and makes it a non-ivar
2346  // writer-barrier conservatively.
2347  ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2348  if (ExpTy->isRecordType()) {
2349  LV.setObjCIvar(false);
2350  return;
2351  }
2352  }
2353  LV.setObjCIvar(true);
2354  auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E));
2355  LV.setBaseIvarExp(Exp->getBase());
2356  LV.setObjCArray(E->getType()->isArrayType());
2357  return;
2358  }
2359 
2360  if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) {
2361  if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) {
2362  if (VD->hasGlobalStorage()) {
2363  LV.setGlobalObjCRef(true);
2364  LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None);
2365  }
2366  }
2367  LV.setObjCArray(E->getType()->isArrayType());
2368  return;
2369  }
2370 
2371  if (const auto *Exp = dyn_cast<UnaryOperator>(E)) {
2372  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2373  return;
2374  }
2375 
2376  if (const auto *Exp = dyn_cast<ParenExpr>(E)) {
2377  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2378  if (LV.isObjCIvar()) {
2379  // If cast is to a structure pointer, follow gcc's behavior and make it
2380  // a non-ivar write-barrier.
2381  QualType ExpTy = E->getType();
2382  if (ExpTy->isPointerType())
2383  ExpTy = ExpTy->castAs<PointerType>()->getPointeeType();
2384  if (ExpTy->isRecordType())
2385  LV.setObjCIvar(false);
2386  }
2387  return;
2388  }
2389 
2390  if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) {
2391  setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV);
2392  return;
2393  }
2394 
2395  if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) {
2396  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2397  return;
2398  }
2399 
2400  if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) {
2401  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2402  return;
2403  }
2404 
2405  if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) {
2406  setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess);
2407  return;
2408  }
2409 
2410  if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) {
2411  setObjCGCLValueClass(Ctx, Exp->getBase(), LV);
2412  if (LV.isObjCIvar() && !LV.isObjCArray())
2413  // Using array syntax to assigning to what an ivar points to is not
2414  // same as assigning to the ivar itself. {id *Names;} Names[i] = 0;
2415  LV.setObjCIvar(false);
2416  else if (LV.isGlobalObjCRef() && !LV.isObjCArray())
2417  // Using array syntax to assigning to what global points to is not
2418  // same as assigning to the global itself. {id *G;} G[i] = 0;
2419  LV.setGlobalObjCRef(false);
2420  return;
2421  }
2422 
2423  if (const auto *Exp = dyn_cast<MemberExpr>(E)) {
2424  setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true);
2425  // We don't know if member is an 'ivar', but this flag is looked at
2426  // only in the context of LV.isObjCIvar().
2427  LV.setObjCArray(E->getType()->isArrayType());
2428  return;
2429  }
2430 }
2431 
2432 static llvm::Value *
2434  llvm::Value *V, llvm::Type *IRType,
2435  StringRef Name = StringRef()) {
2436  unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace();
2437  return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name);
2438 }
2439 
2441  CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr,
2442  llvm::Type *RealVarTy, SourceLocation Loc) {
2443  if (CGF.CGM.getLangOpts().OpenMPIRBuilder)
2445  CGF, VD, Addr, Loc);
2446  else
2447  Addr =
2448  CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc);
2449 
2450  Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy);
2451  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2452 }
2453 
2455  const VarDecl *VD, QualType T) {
2457  OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD);
2458  // Return an invalid address if variable is MT_To and unified
2459  // memory is not enabled. For all other cases: MT_Link and
2460  // MT_To with unified memory, return a valid address.
2461  if (!Res || (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2463  return Address::invalid();
2464  assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) ||
2465  (*Res == OMPDeclareTargetDeclAttr::MT_To &&
2467  "Expected link clause OR to clause with unified memory enabled.");
2468  QualType PtrTy = CGF.getContext().getPointerType(VD->getType());
2470  return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>());
2471 }
2472 
2473 Address
2475  LValueBaseInfo *PointeeBaseInfo,
2476  TBAAAccessInfo *PointeeTBAAInfo) {
2477  llvm::LoadInst *Load =
2478  Builder.CreateLoad(RefLVal.getAddress(*this), RefLVal.isVolatile());
2480 
2481  QualType PointeeType = RefLVal.getType()->getPointeeType();
2483  PointeeType, PointeeBaseInfo, PointeeTBAAInfo,
2484  /* forPointeeType= */ true);
2485  return Address(Load, ConvertTypeForMem(PointeeType), Align);
2486 }
2487 
2489  LValueBaseInfo PointeeBaseInfo;
2490  TBAAAccessInfo PointeeTBAAInfo;
2491  Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo,
2492  &PointeeTBAAInfo);
2493  return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(),
2494  PointeeBaseInfo, PointeeTBAAInfo);
2495 }
2496 
2498  const PointerType *PtrTy,
2499  LValueBaseInfo *BaseInfo,
2500  TBAAAccessInfo *TBAAInfo) {
2501  llvm::Value *Addr = Builder.CreateLoad(Ptr);
2502  return Address(Addr, CGM.getNaturalTypeAlignment(PtrTy->getPointeeType(),
2503  BaseInfo, TBAAInfo,
2504  /*forPointeeType=*/true));
2505 }
2506 
2508  const PointerType *PtrTy) {
2509  LValueBaseInfo BaseInfo;
2510  TBAAAccessInfo TBAAInfo;
2511  Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo);
2512  return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo);
2513 }
2514 
2516  const Expr *E, const VarDecl *VD) {
2517  QualType T = E->getType();
2518 
2519  // If it's thread_local, emit a call to its wrapper function instead.
2520  if (VD->getTLSKind() == VarDecl::TLS_Dynamic &&
2522  return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T);
2523  // Check if the variable is marked as declare target with link clause in
2524  // device codegen.
2525  if (CGF.getLangOpts().OpenMPIsDevice) {
2526  Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T);
2527  if (Addr.isValid())
2528  return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2529  }
2530 
2531  llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD);
2532  llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType());
2533  V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy);
2534  CharUnits Alignment = CGF.getContext().getDeclAlign(VD);
2535  Address Addr(V, RealVarTy, Alignment);
2536  // Emit reference to the private copy of the variable if it is an OpenMP
2537  // threadprivate variable.
2538  if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd &&
2539  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2540  return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy,
2541  E->getExprLoc());
2542  }
2543  LValue LV = VD->getType()->isReferenceType() ?
2544  CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
2546  CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2547  setObjCGCLValueClass(CGF.getContext(), E, LV);
2548  return LV;
2549 }
2550 
2551 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
2552  GlobalDecl GD) {
2553  const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2554  if (FD->hasAttr<WeakRefAttr>()) {
2555  ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
2556  return aliasee.getPointer();
2557  }
2558 
2559  llvm::Constant *V = CGM.GetAddrOfFunction(GD);
2560  if (!FD->hasPrototype()) {
2561  if (const FunctionProtoType *Proto =
2562  FD->getType()->getAs<FunctionProtoType>()) {
2563  // Ugly case: for a K&R-style definition, the type of the definition
2564  // isn't the same as the type of a use. Correct for this with a
2565  // bitcast.
2566  QualType NoProtoType =
2567  CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
2568  NoProtoType = CGM.getContext().getPointerType(NoProtoType);
2569  V = llvm::ConstantExpr::getBitCast(V,
2570  CGM.getTypes().ConvertType(NoProtoType));
2571  }
2572  }
2573  return V;
2574 }
2575 
2577  GlobalDecl GD) {
2578  const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
2580  CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
2581  return CGF.MakeAddrLValue(V, E->getType(), Alignment,
2583 }
2584 
2586  llvm::Value *ThisValue) {
2588  LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType);
2589  return CGF.EmitLValueForField(LV, FD);
2590 }
2591 
2592 /// Named Registers are named metadata pointing to the register name
2593 /// which will be read from/written to as an argument to the intrinsic
2594 /// @llvm.read/write_register.
2595 /// So far, only the name is being passed down, but other options such as
2596 /// register type, allocation type or even optimization options could be
2597 /// passed down via the metadata node.
2599  SmallString<64> Name("llvm.named.register.");
2600  AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>();
2601  assert(Asm->getLabel().size() < 64-Name.size() &&
2602  "Register name too big");
2603  Name.append(Asm->getLabel());
2604  llvm::NamedMDNode *M =
2605  CGM.getModule().getOrInsertNamedMetadata(Name);
2606  if (M->getNumOperands() == 0) {
2607  llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(),
2608  Asm->getLabel());
2609  llvm::Metadata *Ops[] = {Str};
2610  M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops));
2611  }
2612 
2613  CharUnits Alignment = CGM.getContext().getDeclAlign(VD);
2614 
2615  llvm::Value *Ptr =
2616  llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0));
2617  return LValue::MakeGlobalReg(Ptr, Alignment, VD->getType());
2618 }
2619 
2620 /// Determine whether we can emit a reference to \p VD from the current
2621 /// context, despite not necessarily having seen an odr-use of the variable in
2622 /// this context.
2624  const DeclRefExpr *E,
2625  const VarDecl *VD,
2626  bool IsConstant) {
2627  // For a variable declared in an enclosing scope, do not emit a spurious
2628  // reference even if we have a capture, as that will emit an unwarranted
2629  // reference to our capture state, and will likely generate worse code than
2630  // emitting a local copy.
2632  return false;
2633 
2634  // For a local declaration declared in this function, we can always reference
2635  // it even if we don't have an odr-use.
2636  if (VD->hasLocalStorage()) {
2637  return VD->getDeclContext() ==
2638  dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl);
2639  }
2640 
2641  // For a global declaration, we can emit a reference to it if we know
2642  // for sure that we are able to emit a definition of it.
2643  VD = VD->getDefinition(CGF.getContext());
2644  if (!VD)
2645  return false;
2646 
2647  // Don't emit a spurious reference if it might be to a variable that only
2648  // exists on a different device / target.
2649  // FIXME: This is unnecessarily broad. Check whether this would actually be a
2650  // cross-target reference.
2651  if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA ||
2652  CGF.getLangOpts().OpenCL) {
2653  return false;
2654  }
2655 
2656  // We can emit a spurious reference only if the linkage implies that we'll
2657  // be emitting a non-interposable symbol that will be retained until link
2658  // time.
2659  switch (CGF.CGM.getLLVMLinkageVarDefinition(VD, IsConstant)) {
2661  case llvm::GlobalValue::LinkOnceODRLinkage:
2662  case llvm::GlobalValue::WeakODRLinkage:
2664  case llvm::GlobalValue::PrivateLinkage:
2665  return true;
2666  default:
2667  return false;
2668  }
2669 }
2670 
2672  const NamedDecl *ND = E->getDecl();
2673  QualType T = E->getType();
2674 
2675  assert(E->isNonOdrUse() != NOUR_Unevaluated &&
2676  "should not emit an unevaluated operand");
2677 
2678  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2679  // Global Named registers access via intrinsics only
2680  if (VD->getStorageClass() == SC_Register &&
2681  VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl())
2682  return EmitGlobalNamedRegister(VD, CGM);
2683 
2684  // If this DeclRefExpr does not constitute an odr-use of the variable,
2685  // we're not permitted to emit a reference to it in general, and it might
2686  // not be captured if capture would be necessary for a use. Emit the
2687  // constant value directly instead.
2688  if (E->isNonOdrUse() == NOUR_Constant &&
2689  (VD->getType()->isReferenceType() ||
2690  !canEmitSpuriousReferenceToVariable(*this, E, VD, true))) {
2691  VD->getAnyInitializer(VD);
2692  llvm::Constant *Val = ConstantEmitter(*this).emitAbstract(
2693  E->getLocation(), *VD->evaluateValue(), VD->getType());
2694  assert(Val && "failed to emit constant expression");
2695 
2696  Address Addr = Address::invalid();
2697  if (!VD->getType()->isReferenceType()) {
2698  // Spill the constant value to a global.
2699  Addr = CGM.createUnnamedGlobalFrom(*VD, Val,
2700  getContext().getDeclAlign(VD));
2701  llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType());
2702  auto *PTy = llvm::PointerType::get(
2703  VarTy, getContext().getTargetAddressSpace(VD->getType()));
2704  if (PTy != Addr.getType())
2705  Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy);
2706  } else {
2707  // Should we be using the alignment of the constant pointer we emitted?
2708  CharUnits Alignment =
2710  /* BaseInfo= */ nullptr,
2711  /* TBAAInfo= */ nullptr,
2712  /* forPointeeType= */ true);
2713  Addr = Address(Val, ConvertTypeForMem(E->getType()), Alignment);
2714  }
2715  return MakeAddrLValue(Addr, T, AlignmentSource::Decl);
2716  }
2717 
2718  // FIXME: Handle other kinds of non-odr-use DeclRefExprs.
2719 
2720  // Check for captured variables.
2722  VD = VD->getCanonicalDecl();
2723  if (auto *FD = LambdaCaptureFields.lookup(VD))
2724  return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue);
2725  if (CapturedStmtInfo) {
2726  auto I = LocalDeclMap.find(VD);
2727  if (I != LocalDeclMap.end()) {
2728  LValue CapLVal;
2729  if (VD->getType()->isReferenceType())
2730  CapLVal = EmitLoadOfReferenceLValue(I->second, VD->getType(),
2732  else
2733  CapLVal = MakeAddrLValue(I->second, T);
2734  // Mark lvalue as nontemporal if the variable is marked as nontemporal
2735  // in simd context.
2736  if (getLangOpts().OpenMP &&
2738  CapLVal.setNontemporal(/*Value=*/true);
2739  return CapLVal;
2740  }
2741  LValue CapLVal =
2744  CapLVal = MakeAddrLValue(
2745  Address(CapLVal.getPointer(*this), getContext().getDeclAlign(VD)),
2747  CapLVal.getTBAAInfo());
2748  // Mark lvalue as nontemporal if the variable is marked as nontemporal
2749  // in simd context.
2750  if (getLangOpts().OpenMP &&
2752  CapLVal.setNontemporal(/*Value=*/true);
2753  return CapLVal;
2754  }
2755 
2756  assert(isa<BlockDecl>(CurCodeDecl));
2757  Address addr = GetAddrOfBlockDecl(VD);
2758  return MakeAddrLValue(addr, T, AlignmentSource::Decl);
2759  }
2760  }
2761 
2762  // FIXME: We should be able to assert this for FunctionDecls as well!
2763  // FIXME: We should be able to assert this for all DeclRefExprs, not just
2764  // those with a valid source location.
2765  assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() ||
2766  !E->getLocation().isValid()) &&
2767  "Should not use decl without marking it used!");
2768 
2769  if (ND->hasAttr<WeakRefAttr>()) {
2770  const auto *VD = cast<ValueDecl>(ND);
2771  ConstantAddress Aliasee = CGM.GetWeakRefReference(VD);
2772  return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl);
2773  }
2774 
2775  if (const auto *VD = dyn_cast<VarDecl>(ND)) {
2776  // Check if this is a global variable.
2777  if (VD->hasLinkage() || VD->isStaticDataMember())
2778  return EmitGlobalVarDeclLValue(*this, E, VD);
2779 
2780  Address addr = Address::invalid();
2781 
2782  // The variable should generally be present in the local decl map.
2783  auto iter = LocalDeclMap.find(VD);
2784  if (iter != LocalDeclMap.end()) {
2785  addr = iter->second;
2786 
2787  // Otherwise, it might be static local we haven't emitted yet for
2788  // some reason; most likely, because it's in an outer function.
2789  } else if (VD->isStaticLocal()) {
2790  llvm::Constant *var = CGM.getOrCreateStaticVarDecl(
2791  *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false));
2792  addr = Address(
2793  var, ConvertTypeForMem(VD->getType()), getContext().getDeclAlign(VD));
2794 
2795  // No other cases for now.
2796  } else {
2797  llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?");
2798  }
2799 
2800 
2801  // Check for OpenMP threadprivate variables.
2802  if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd &&
2803  VD->hasAttr<OMPThreadPrivateDeclAttr>()) {
2805  *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()),
2806  E->getExprLoc());
2807  }
2808 
2809  // Drill into block byref variables.
2810  bool isBlockByref = VD->isEscapingByref();
2811  if (isBlockByref) {
2812  addr = emitBlockByrefAddress(addr, VD);
2813  }
2814 
2815  // Drill into reference types.
2816  LValue LV = VD->getType()->isReferenceType() ?
2819 
2820  bool isLocalStorage = VD->hasLocalStorage();
2821 
2822  bool NonGCable = isLocalStorage &&
2823  !VD->getType()->isReferenceType() &&
2824  !isBlockByref;
2825  if (NonGCable) {
2826  LV.getQuals().removeObjCGCAttr();
2827  LV.setNonGC(true);
2828  }
2829 
2830  bool isImpreciseLifetime =
2831  (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>());
2832  if (isImpreciseLifetime)
2834  setObjCGCLValueClass(getContext(), E, LV);
2835  return LV;
2836  }
2837 
2838  if (const auto *FD = dyn_cast<FunctionDecl>(ND)) {
2839  LValue LV = EmitFunctionDeclLValue(*this, E, FD);
2840 
2841  // Emit debuginfo for the function declaration if the target wants to.
2842  if (getContext().getTargetInfo().allowDebugInfoForExternalRef()) {
2843  if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) {
2844  auto *Fn =
2845  cast<llvm::Function>(LV.getPointer(*this)->stripPointerCasts());
2846  if (!Fn->getSubprogram())
2847  DI->EmitFunctionDecl(FD, FD->getLocation(), T, Fn);
2848  }
2849  }
2850 
2851  return LV;
2852  }
2853 
2854  // FIXME: While we're emitting a binding from an enclosing scope, all other
2855  // DeclRefExprs we see should be implicitly treated as if they also refer to
2856  // an enclosing scope.
2857  if (const auto *BD = dyn_cast<BindingDecl>(ND))
2858  return EmitLValue(BD->getBinding());
2859 
2860  // We can form DeclRefExprs naming GUID declarations when reconstituting
2861  // non-type template parameters into expressions.
2862  if (const auto *GD = dyn_cast<MSGuidDecl>(ND))
2863  return MakeAddrLValue(CGM.GetAddrOfMSGuidDecl(GD), T,
2865 
2866  if (const auto *TPO = dyn_cast<TemplateParamObjectDecl>(ND))
2869 
2870  llvm_unreachable("Unhandled DeclRefExpr");
2871 }
2872 
2874  // __extension__ doesn't affect lvalue-ness.
2875  if (E->getOpcode() == UO_Extension)
2876  return EmitLValue(E->getSubExpr());
2877 
2879  switch (E->getOpcode()) {
2880  default: llvm_unreachable("Unknown unary operator lvalue!");
2881  case UO_Deref: {
2882  QualType T = E->getSubExpr()->getType()->getPointeeType();
2883  assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type");
2884 
2885  LValueBaseInfo BaseInfo;
2886  TBAAAccessInfo TBAAInfo;
2887  Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo,
2888  &TBAAInfo);
2889  LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo);
2890  LV.getQuals().setAddressSpace(ExprTy.getAddressSpace());
2891 
2892  // We should not generate __weak write barrier on indirect reference
2893  // of a pointer to object; as in void foo (__weak id *param); *param = 0;
2894  // But, we continue to generate __strong write barrier on indirect write
2895  // into a pointer to object.
2896  if (getLangOpts().ObjC &&
2897  getLangOpts().getGC() != LangOptions::NonGC &&
2898  LV.isObjCWeak())
2900  return LV;
2901  }
2902  case UO_Real:
2903  case UO_Imag: {
2904  LValue LV = EmitLValue(E->getSubExpr());
2905  assert(LV.isSimple() && "real/imag on non-ordinary l-value");
2906 
2907  // __real is valid on scalars. This is a faster way of testing that.
2908  // __imag can only produce an rvalue on scalars.
2909  if (E->getOpcode() == UO_Real &&
2910  !LV.getAddress(*this).getElementType()->isStructTy()) {
2911  assert(E->getSubExpr()->getType()->isArithmeticType());
2912  return LV;
2913  }
2914 
2915  QualType T = ExprTy->castAs<ComplexType>()->getElementType();
2916 
2917  Address Component =
2918  (E->getOpcode() == UO_Real
2919  ? emitAddrOfRealComponent(LV.getAddress(*this), LV.getType())
2920  : emitAddrOfImagComponent(LV.getAddress(*this), LV.getType()));
2921  LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(),
2922  CGM.getTBAAInfoForSubobject(LV, T));
2923  ElemLV.getQuals().addQualifiers(LV.getQuals());
2924  return ElemLV;
2925  }
2926  case UO_PreInc:
2927  case UO_PreDec: {
2928  LValue LV = EmitLValue(E->getSubExpr());
2929  bool isInc = E->getOpcode() == UO_PreInc;
2930 
2931  if (E->getType()->isAnyComplexType())
2932  EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/);
2933  else
2934  EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/);
2935  return LV;
2936  }
2937  }
2938 }
2939 
2943 }
2944 
2948 }
2949 
2951  auto SL = E->getFunctionName();
2952  assert(SL != nullptr && "No StringLiteral name in PredefinedExpr");
2953  StringRef FnName = CurFn->getName();
2954  if (FnName.startswith("\01"))
2955  FnName = FnName.substr(1);
2956  StringRef NameItems[] = {
2958  std::string GVName = llvm::join(NameItems, NameItems + 2, ".");
2959  if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) {
2960  std::string Name = std::string(SL->getString());
2961  if (!Name.empty()) {
2962  unsigned Discriminator =
2963  CGM.getCXXABI().getMangleContext().getBlockId(BD, true);
2964  if (Discriminator)
2965  Name += "_" + Twine(Discriminator + 1).str();
2966  auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str());
2967  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2968  } else {
2969  auto C =
2970  CGM.GetAddrOfConstantCString(std::string(FnName), GVName.c_str());
2971  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2972  }
2973  }
2974  auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName);
2975  return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl);
2976 }
2977 
2978 /// Emit a type description suitable for use by a runtime sanitizer library. The
2979 /// format of a type descriptor is
2980 ///
2981 /// \code
2982 /// { i16 TypeKind, i16 TypeInfo }
2983 /// \endcode
2984 ///
2985 /// followed by an array of i8 containing the type name. TypeKind is 0 for an
2986 /// integer, 1 for a floating point value, and -1 for anything else.
2988  // Only emit each type's descriptor once.
2989  if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T))
2990  return C;
2991 
2992  uint16_t TypeKind = -1;
2993  uint16_t TypeInfo = 0;
2994 
2995  if (T->isIntegerType()) {
2996  TypeKind = 0;
2997  TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) |
2998  (T->isSignedIntegerType() ? 1 : 0);
2999  } else if (T->isFloatingType()) {
3000  TypeKind = 1;
3002  }
3003 
3004  // Format the type name as if for a diagnostic, including quotes and
3005  // optionally an 'aka'.
3006  SmallString<32> Buffer;
3008  (intptr_t)T.getAsOpaquePtr(),
3009  StringRef(), StringRef(), None, Buffer,
3010  None);
3011 
3012  llvm::Constant *Components[] = {
3013  Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo),
3014  llvm::ConstantDataArray::getString(getLLVMContext(), Buffer)
3015  };
3016  llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components);
3017 
3018  auto *GV = new llvm::GlobalVariable(
3019  CGM.getModule(), Descriptor->getType(),
3020  /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor);
3021  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3023 
3024  // Remember the descriptor for this type.
3025  CGM.setTypeDescriptorInMap(T, GV);
3026 
3027  return GV;
3028 }
3029 
3031  llvm::Type *TargetTy = IntPtrTy;
3032 
3033  if (V->getType() == TargetTy)
3034  return V;
3035 
3036  // Floating-point types which fit into intptr_t are bitcast to integers
3037  // and then passed directly (after zero-extension, if necessary).
3038  if (V->getType()->isFloatingPointTy()) {
3039  unsigned Bits = V->getType()->getPrimitiveSizeInBits().getFixedSize();
3040  if (Bits <= TargetTy->getIntegerBitWidth())
3041  V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(),
3042  Bits));
3043  }
3044 
3045  // Integers which fit in intptr_t are zero-extended and passed directly.
3046  if (V->getType()->isIntegerTy() &&
3047  V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth())
3048  return Builder.CreateZExt(V, TargetTy);
3049 
3050  // Pointers are passed directly, everything else is passed by address.
3051  if (!V->getType()->isPointerTy()) {
3052  Address Ptr = CreateDefaultAlignTempAlloca(V->getType());
3053  Builder.CreateStore(V, Ptr);
3054  V = Ptr.getPointer();
3055  }
3056  return Builder.CreatePtrToInt(V, TargetTy);
3057 }
3058 
3059 /// Emit a representation of a SourceLocation for passing to a handler
3060 /// in a sanitizer runtime library. The format for this data is:
3061 /// \code
3062 /// struct SourceLocation {
3063 /// const char *Filename;
3064 /// int32_t Line, Column;
3065 /// };
3066 /// \endcode
3067 /// For an invalid SourceLocation, the Filename pointer is null.
3069  llvm::Constant *Filename;
3070  int Line, Column;
3071 
3073  if (PLoc.isValid()) {
3074  StringRef FilenameString = PLoc.getFilename();
3075 
3076  int PathComponentsToStrip =
3077  CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip;
3078  if (PathComponentsToStrip < 0) {
3079  assert(PathComponentsToStrip != INT_MIN);
3080  int PathComponentsToKeep = -PathComponentsToStrip;
3081  auto I = llvm::sys::path::rbegin(FilenameString);
3082  auto E = llvm::sys::path::rend(FilenameString);
3083  while (I != E && --PathComponentsToKeep)
3084  ++I;
3085 
3086  FilenameString = FilenameString.substr(I - E);
3087  } else if (PathComponentsToStrip > 0) {
3088  auto I = llvm::sys::path::begin(FilenameString);
3089  auto E = llvm::sys::path::end(FilenameString);
3090  while (I != E && PathComponentsToStrip--)
3091  ++I;
3092 
3093  if (I != E)
3094  FilenameString =
3095  FilenameString.substr(I - llvm::sys::path::begin(FilenameString));
3096  else
3097  FilenameString = llvm::sys::path::filename(FilenameString);
3098  }
3099 
3100  auto FilenameGV =
3101  CGM.GetAddrOfConstantCString(std::string(FilenameString), ".src");
3103  cast<llvm::GlobalVariable>(FilenameGV.getPointer()));
3104  Filename = FilenameGV.getPointer();
3105  Line = PLoc.getLine();
3106  Column = PLoc.getColumn();
3107  } else {
3108  Filename = llvm::Constant::getNullValue(Int8PtrTy);
3109  Line = Column = 0;
3110  }
3111 
3112  llvm::Constant *Data[] = {Filename, Builder.getInt32(Line),
3113  Builder.getInt32(Column)};
3114 
3115  return llvm::ConstantStruct::getAnon(Data);
3116 }
3117 
3118 namespace {
3119 /// Specify under what conditions this check can be recovered
3120 enum class CheckRecoverableKind {
3121  /// Always terminate program execution if this check fails.
3122  Unrecoverable,
3123  /// Check supports recovering, runtime has both fatal (noreturn) and
3124  /// non-fatal handlers for this check.
3125  Recoverable,
3126  /// Runtime conditionally aborts, always need to support recovery.
3127  AlwaysRecoverable
3128 };
3129 }
3130 
3131 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) {
3132  assert(Kind.countPopulation() == 1);
3133  if (Kind == SanitizerKind::Function || Kind == SanitizerKind::Vptr)
3135  else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable)
3137  else
3138  return CheckRecoverableKind::Recoverable;
3139 }
3140 
3141 namespace {
3142 struct SanitizerHandlerInfo {
3143  char const *const Name;
3144  unsigned Version;
3145 };
3146 }
3147 
3148 const SanitizerHandlerInfo SanitizerHandlers[] = {
3149 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version},
3151 #undef SANITIZER_CHECK
3152 };
3153 
3155  llvm::FunctionType *FnType,
3156  ArrayRef<llvm::Value *> FnArgs,
3157  SanitizerHandler CheckHandler,
3158  CheckRecoverableKind RecoverKind, bool IsFatal,
3159  llvm::BasicBlock *ContBB) {
3160  assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable);
3162  if (!CGF.Builder.getCurrentDebugLocation()) {
3163  // Ensure that the call has at least an artificial debug location.
3164  DL.emplace(CGF, SourceLocation());
3165  }
3166  bool NeedsAbortSuffix =
3167  IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable;
3168  bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime;
3169  const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler];
3170  const StringRef CheckName = CheckInfo.Name;
3171  std::string FnName = "__ubsan_handle_" + CheckName.str();
3172  if (CheckInfo.Version && !MinimalRuntime)
3173  FnName += "_v" + llvm::utostr(CheckInfo.Version);
3174  if (MinimalRuntime)
3175  FnName += "_minimal";
3176  if (NeedsAbortSuffix)
3177  FnName += "_abort";
3178  bool MayReturn =
3179  !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable;
3180 
3181  llvm::AttrBuilder B(CGF.getLLVMContext());
3182  if (!MayReturn) {
3183  B.addAttribute(llvm::Attribute::NoReturn)
3184  .addAttribute(llvm::Attribute::NoUnwind);
3185  }
3186  B.addAttribute(llvm::Attribute::UWTable);
3187 
3188  llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction(
3189  FnType, FnName,
3190  llvm::AttributeList::get(CGF.getLLVMContext(),
3191  llvm::AttributeList::FunctionIndex, B),
3192  /*Local=*/true);
3193  llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs);
3194  if (!MayReturn) {
3195  HandlerCall->setDoesNotReturn();
3196  CGF.Builder.CreateUnreachable();
3197  } else {
3198  CGF.Builder.CreateBr(ContBB);
3199  }
3200 }
3201 
3203  ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked,
3204  SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs,
3205  ArrayRef<llvm::Value *> DynamicArgs) {
3206  assert(IsSanitizerScope);
3207  assert(Checked.size() > 0);
3208  assert(CheckHandler >= 0 &&
3209  size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers));
3210  const StringRef CheckName = SanitizerHandlers[CheckHandler].Name;
3211 
3212  llvm::Value *FatalCond = nullptr;
3213  llvm::Value *RecoverableCond = nullptr;
3214  llvm::Value *TrapCond = nullptr;
3215  for (int i = 0, n = Checked.size(); i < n; ++i) {
3216  llvm::Value *Check = Checked[i].first;
3217  // -fsanitize-trap= overrides -fsanitize-recover=.
3218  llvm::Value *&Cond =
3219  CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second)
3220  ? TrapCond
3221  : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second)
3222  ? RecoverableCond
3223  : FatalCond;
3224  Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check;
3225  }
3226 
3227  if (TrapCond)
3228  EmitTrapCheck(TrapCond, CheckHandler);
3229  if (!FatalCond && !RecoverableCond)
3230  return;
3231 
3232  llvm::Value *JointCond;
3233  if (FatalCond && RecoverableCond)
3234  JointCond = Builder.CreateAnd(FatalCond, RecoverableCond);
3235  else
3236  JointCond = FatalCond ? FatalCond : RecoverableCond;
3237  assert(JointCond);
3238 
3239  CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second);
3240  assert(SanOpts.has(Checked[0].second));
3241 #ifndef NDEBUG
3242  for (int i = 1, n = Checked.size(); i < n; ++i) {
3243  assert(RecoverKind == getRecoverableKind(Checked[i].second) &&
3244  "All recoverable kinds in a single check must be same!");
3245  assert(SanOpts.has(Checked[i].second));
3246  }
3247 #endif
3248 
3249  llvm::BasicBlock *Cont = createBasicBlock("cont");
3250  llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName);
3251  llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers);
3252  // Give hint that we very much don't expect to execute the handler
3253  // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp
3254  llvm::MDBuilder MDHelper(getLLVMContext());
3255  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3256  Branch->setMetadata(llvm::LLVMContext::MD_prof, Node);
3257  EmitBlock(Handlers);
3258 
3259  // Handler functions take an i8* pointing to the (handler-specific) static
3260  // information block, followed by a sequence of intptr_t arguments
3261  // representing operand values.
3264  if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) {
3265  Args.reserve(DynamicArgs.size() + 1);
3266  ArgTypes.reserve(DynamicArgs.size() + 1);
3267 
3268  // Emit handler arguments and create handler function type.
3269  if (!StaticArgs.empty()) {
3270  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3271  auto *InfoPtr =
3272  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3273  llvm::GlobalVariable::PrivateLinkage, Info);
3274  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3276  Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy));
3277  ArgTypes.push_back(Int8PtrTy);
3278  }
3279 
3280  for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) {
3281  Args.push_back(EmitCheckValue(DynamicArgs[i]));
3282  ArgTypes.push_back(IntPtrTy);
3283  }
3284  }
3285 
3286  llvm::FunctionType *FnType =
3287  llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false);
3288 
3289  if (!FatalCond || !RecoverableCond) {
3290  // Simple case: we need to generate a single handler call, either
3291  // fatal, or non-fatal.
3292  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind,
3293  (FatalCond != nullptr), Cont);
3294  } else {
3295  // Emit two handler calls: first one for set of unrecoverable checks,
3296  // another one for recoverable.
3297  llvm::BasicBlock *NonFatalHandlerBB =
3298  createBasicBlock("non_fatal." + CheckName);
3299  llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName);
3300  Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB);
3301  EmitBlock(FatalHandlerBB);
3302  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true,
3303  NonFatalHandlerBB);
3304  EmitBlock(NonFatalHandlerBB);
3305  emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false,
3306  Cont);
3307  }
3308 
3309  EmitBlock(Cont);
3310 }
3311 
3313  SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId,
3314  llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) {
3315  llvm::BasicBlock *Cont = createBasicBlock("cfi.cont");
3316 
3317  llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath");
3318  llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB);
3319 
3320  llvm::MDBuilder MDHelper(getLLVMContext());
3321  llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1);
3322  BI->setMetadata(llvm::LLVMContext::MD_prof, Node);
3323 
3324  EmitBlock(CheckBB);
3325 
3326  bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind);
3327 
3328  llvm::CallInst *CheckCall;
3329  llvm::FunctionCallee SlowPathFn;
3330  if (WithDiag) {
3331  llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs);
3332  auto *InfoPtr =
3333  new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false,
3334  llvm::GlobalVariable::PrivateLinkage, Info);
3335  InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
3337 
3338  SlowPathFn = CGM.getModule().getOrInsertFunction(
3339  "__cfi_slowpath_diag",
3340  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy},
3341  false));
3342  CheckCall = Builder.CreateCall(
3343  SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)});
3344  } else {
3345  SlowPathFn = CGM.getModule().getOrInsertFunction(
3346  "__cfi_slowpath",
3347  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false));
3348  CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr});
3349  }
3350 
3351  CGM.setDSOLocal(
3352  cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts()));
3353  CheckCall->setDoesNotThrow();
3354 
3355  EmitBlock(Cont);
3356 }
3357 
3358 // Emit a stub for __cfi_check function so that the linker knows about this
3359 // symbol in LTO mode.
3361  llvm::Module *M = &CGM.getModule();
3362  auto &Ctx = M->getContext();
3363  llvm::Function *F = llvm::Function::Create(
3364  llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false),
3365  llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M);
3366  CGM.setDSOLocal(F);
3367  llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F);
3368  // FIXME: consider emitting an intrinsic call like
3369  // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2)
3370  // which can be lowered in CrossDSOCFI pass to the actual contents of
3371  // __cfi_check. This would allow inlining of __cfi_check calls.
3372  llvm::CallInst::Create(
3373  llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB);
3374  llvm::ReturnInst::Create(Ctx, nullptr, BB);
3375 }
3376 
3377 // This function is basically a switch over the CFI failure kind, which is
3378 // extracted from CFICheckFailData (1st function argument). Each case is either
3379 // llvm.trap or a call to one of the two runtime handlers, based on
3380 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid
3381 // failure kind) traps, but this should really never happen. CFICheckFailData
3382 // can be nullptr if the calling module has -fsanitize-trap behavior for this
3383 // check kind; in this case __cfi_check_fail traps as well.
3385  SanitizerScope SanScope(this);
3386  FunctionArgList Args;
3391  Args.push_back(&ArgData);
3392  Args.push_back(&ArgAddr);
3393 
3394  const CGFunctionInfo &FI =
3396 
3397  llvm::Function *F = llvm::Function::Create(
3398  llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false),
3399  llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule());
3400 
3401  CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F, /*IsThunk=*/false);
3403  F->setVisibility(llvm::GlobalValue::HiddenVisibility);
3404 
3405  StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args,
3406  SourceLocation());
3407 
3408  // This function is not affected by NoSanitizeList. This function does
3409  // not have a source location, but "src:*" would still apply. Revert any
3410  // changes to SanOpts made in StartFunction.
3412 
3413  llvm::Value *Data =
3414  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false,
3415  CGM.getContext().VoidPtrTy, ArgData.getLocation());
3416  llvm::Value *Addr =
3417  EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false,
3418  CGM.getContext().VoidPtrTy, ArgAddr.getLocation());
3419 
3420  // Data == nullptr means the calling module has trap behaviour for this check.
3421  llvm::Value *DataIsNotNullPtr =
3422  Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy));
3423  EmitTrapCheck(DataIsNotNullPtr, SanitizerHandler::CFICheckFail);
3424 
3425  llvm::StructType *SourceLocationTy =
3426  llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty);
3427  llvm::StructType *CfiCheckFailDataTy =
3428  llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy);
3429 
3430  llvm::Value *V = Builder.CreateConstGEP2_32(
3431  CfiCheckFailDataTy,
3432  Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0,
3433  0);
3434  Address CheckKindAddr(V, getIntAlign());
3435  llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr);
3436 
3437  llvm::Value *AllVtables = llvm::MetadataAsValue::get(
3438  CGM.getLLVMContext(),
3439  llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
3440  llvm::Value *ValidVtable = Builder.CreateZExt(
3441  Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test),
3442  {Addr, AllVtables}),
3443  IntPtrTy);
3444 
3445  const std::pair<int, SanitizerMask> CheckKinds[] = {
3446  {CFITCK_VCall, SanitizerKind::CFIVCall},
3447  {CFITCK_NVCall, SanitizerKind::CFINVCall},
3448  {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast},
3449  {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast},
3450  {CFITCK_ICall, SanitizerKind::CFIICall}};
3451 
3453  for (auto CheckKindMaskPair : CheckKinds) {
3454  int Kind = CheckKindMaskPair.first;
3455  SanitizerMask Mask = CheckKindMaskPair.second;
3456  llvm::Value *Cond =
3457  Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind));
3458  if (CGM.getLangOpts().Sanitize.has(Mask))
3459  EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {},
3460  {Data, Addr, ValidVtable});
3461  else
3462  EmitTrapCheck(Cond, SanitizerHandler::CFICheckFail);
3463  }
3464 
3465  FinishFunction();
3466  // The only reference to this function will be created during LTO link.
3467  // Make sure it survives until then.
3468  CGM.addUsedGlobal(F);
3469 }
3470 
3472  if (SanOpts.has(SanitizerKind::Unreachable)) {
3473  SanitizerScope SanScope(this);
3474  EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()),
3475  SanitizerKind::Unreachable),
3476  SanitizerHandler::BuiltinUnreachable,
3477  EmitCheckSourceLocation(Loc), None);
3478  }
3479  Builder.CreateUnreachable();
3480 }
3481 
3483  SanitizerHandler CheckHandlerID) {
3484  llvm::BasicBlock *Cont = createBasicBlock("cont");
3485 
3486  // If we're optimizing, collapse all calls to trap down to just one per
3487  // check-type per function to save on code size.
3488  if (TrapBBs.size() <= CheckHandlerID)
3489  TrapBBs.resize(CheckHandlerID + 1);
3490  llvm::BasicBlock *&TrapBB = TrapBBs[CheckHandlerID];
3491 
3492  if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) {
3493  TrapBB = createBasicBlock("trap");
3494  Builder.CreateCondBr(Checked, Cont, TrapBB);
3495  EmitBlock(TrapBB);
3496 
3497  llvm::CallInst *TrapCall =
3498  Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::ubsantrap),
3499  llvm::ConstantInt::get(CGM.Int8Ty, CheckHandlerID));
3500 
3501  if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3502  auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3504  TrapCall->addFnAttr(A);
3505  }
3506  TrapCall->setDoesNotReturn();
3507  TrapCall->setDoesNotThrow();
3508  Builder.CreateUnreachable();
3509  } else {
3510  auto Call = TrapBB->begin();
3511  assert(isa<llvm::CallInst>(Call) && "Expected call in trap BB");
3512 
3513  Call->applyMergedLocation(Call->getDebugLoc(),
3514  Builder.getCurrentDebugLocation());
3515  Builder.CreateCondBr(Checked, Cont, TrapBB);
3516  }
3517 
3518  EmitBlock(Cont);
3519 }
3520 
3522  llvm::CallInst *TrapCall =
3523  Builder.CreateCall(CGM.getIntrinsic(IntrID));
3524 
3525  if (!CGM.getCodeGenOpts().TrapFuncName.empty()) {
3526  auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name",
3528  TrapCall->addFnAttr(A);
3529  }
3530 
3531  return TrapCall;
3532 }
3533 
3535  LValueBaseInfo *BaseInfo,
3536  TBAAAccessInfo *TBAAInfo) {
3537  assert(E->getType()->isArrayType() &&
3538  "Array to pointer decay must have array source type!");
3539 
3540  // Expressions of array type can't be bitfields or vector elements.
3541  LValue LV = EmitLValue(E);
3542  Address Addr = LV.getAddress(*this);
3543 
3544  // If the array type was an incomplete type, we need to make sure
3545  // the decay ends up being the right type.
3546  llvm::Type *NewTy = ConvertType(E->getType());
3547  Addr = Builder.CreateElementBitCast(Addr, NewTy);
3548 
3549  // Note that VLA pointers are always decayed, so we don't need to do
3550  // anything here.
3551  if (!E->getType()->isVariableArrayType()) {
3552  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3553  "Expected pointer to array");
3554  Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3555  }
3556 
3557  // The result of this decay conversion points to an array element within the
3558  // base lvalue. However, since TBAA currently does not support representing
3559  // accesses to elements of member arrays, we conservatively represent accesses
3560  // to the pointee object as if it had no any base lvalue specified.
3561  // TODO: Support TBAA for member arrays.
3563  if (BaseInfo) *BaseInfo = LV.getBaseInfo();
3564  if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType);
3565 
3566  return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType));
3567 }
3568 
3569 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an
3570 /// array to pointer, return the array subexpression.
3571 static const Expr *isSimpleArrayDecayOperand(const Expr *E) {
3572  // If this isn't just an array->pointer decay, bail out.
3573  const auto *CE = dyn_cast<CastExpr>(E);
3574  if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay)
3575  return nullptr;
3576 
3577  // If this is a decay from variable width array, bail out.
3578  const Expr *SubExpr = CE->getSubExpr();
3579  if (SubExpr->getType()->isVariableArrayType())
3580  return nullptr;
3581 
3582  return SubExpr;
3583 }
3584 
3586  llvm::Type *elemType,
3587  llvm::Value *ptr,
3588  ArrayRef<llvm::Value*> indices,
3589  bool inbounds,
3590  bool signedIndices,
3591  SourceLocation loc,
3592  const llvm::Twine &name = "arrayidx") {
3593  if (inbounds) {
3594  return CGF.EmitCheckedInBoundsGEP(elemType, ptr, indices, signedIndices,
3596  name);
3597  } else {
3598  return CGF.Builder.CreateGEP(elemType, ptr, indices, name);
3599  }
3600 }
3601 
3603  llvm::Value *idx,
3604  CharUnits eltSize) {
3605  // If we have a constant index, we can use the exact offset of the
3606  // element we're accessing.
3607  if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) {
3608  CharUnits offset = constantIdx->getZExtValue() * eltSize;
3609  return arrayAlign.alignmentAtOffset(offset);
3610 
3611  // Otherwise, use the worst-case alignment for any element.
3612  } else {
3613  return arrayAlign.alignmentOfArrayElement(eltSize);
3614  }
3615 }
3616 
3618  const VariableArrayType *vla) {
3619  QualType eltType;
3620  do {
3621  eltType = vla->getElementType();
3622  } while ((vla = ctx.getAsVariableArrayType(eltType)));
3623  return eltType;
3624 }
3625 
3626 /// Given an array base, check whether its member access belongs to a record
3627 /// with preserve_access_index attribute or not.
3628 static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) {
3629  if (!ArrayBase || !CGF.getDebugInfo())
3630  return false;
3631 
3632  // Only support base as either a MemberExpr or DeclRefExpr.
3633  // DeclRefExpr to cover cases like:
3634  // struct s { int a; int b[10]; };
3635  // struct s *p;
3636  // p[1].a
3637  // p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr.
3638  // p->b[5] is a MemberExpr example.
3639  const Expr *E = ArrayBase->IgnoreImpCasts();
3640  if (const auto *ME = dyn_cast<MemberExpr>(E))
3641  return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
3642 
3643  if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) {
3644  const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl());
3645  if (!VarDef)
3646  return false;
3647 
3648  const auto *PtrT = VarDef->getType()->getAs<PointerType>();
3649  if (!PtrT)
3650  return false;
3651 
3652  const auto *PointeeT = PtrT->getPointeeType()
3654  if (const auto *RecT = dyn_cast<RecordType>(PointeeT))
3655  return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>();
3656  return false;
3657  }
3658 
3659  return false;
3660 }
3661 
3663  ArrayRef<llvm::Value *> indices,
3664  QualType eltType, bool inbounds,
3665  bool signedIndices, SourceLocation loc,
3666  QualType *arrayType = nullptr,
3667  const Expr *Base = nullptr,
3668  const llvm::Twine &name = "arrayidx") {
3669  // All the indices except that last must be zero.
3670 #ifndef NDEBUG
3671  for (auto idx : indices.drop_back())
3672  assert(isa<llvm::ConstantInt>(idx) &&
3673  cast<llvm::ConstantInt>(idx)->isZero());
3674 #endif
3675 
3676  // Determine the element size of the statically-sized base. This is
3677  // the thing that the indices are expressed in terms of.
3678  if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) {
3679  eltType = getFixedSizeElementType(CGF.getContext(), vla);
3680  }
3681 
3682  // We can use that to compute the best alignment of the element.
3683  CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType);
3684  CharUnits eltAlign =
3685  getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize);
3686 
3687  llvm::Value *eltPtr;
3688  auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back());
3689  if (!LastIndex ||
3691  eltPtr = emitArraySubscriptGEP(
3692  CGF, addr.getElementType(), addr.getPointer(), indices, inbounds,
3693  signedIndices, loc, name);
3694  } else {
3695  // Remember the original array subscript for bpf target
3696  unsigned idx = LastIndex->getZExtValue();
3697  llvm::DIType *DbgInfo = nullptr;
3698  if (arrayType)
3699  DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc);
3700  eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getElementType(),
3701  addr.getPointer(),
3702  indices.size() - 1,
3703  idx, DbgInfo);
3704  }
3705 
3706  return Address(eltPtr, CGF.ConvertTypeForMem(eltType), eltAlign);
3707 }
3708 
3710  bool Accessed) {
3711  // The index must always be an integer, which is not an aggregate. Emit it
3712  // in lexical order (this complexity is, sadly, required by C++17).
3713  llvm::Value *IdxPre =
3714  (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr;
3715  bool SignedIndices = false;
3716  auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * {
3717  auto *Idx = IdxPre;
3718  if (E->getLHS() != E->getIdx()) {
3719  assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS");
3720  Idx = EmitScalarExpr(E->getIdx());
3721  }
3722 
3723  QualType IdxTy = E->getIdx()->getType();
3724  bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType();
3725  SignedIndices |= IdxSigned;
3726 
3727  if (SanOpts.has(SanitizerKind::ArrayBounds))
3728  EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed);
3729 
3730  // Extend or truncate the index type to 32 or 64-bits.
3731  if (Promote && Idx->getType() != IntPtrTy)
3732  Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom");
3733 
3734  return Idx;
3735  };
3736  IdxPre = nullptr;
3737 
3738  // If the base is a vector type, then we are forming a vector element lvalue
3739  // with this subscript.
3740  if (E->getBase()->getType()->isVectorType() &&
3741  !isa<ExtVectorElementExpr>(E->getBase())) {
3742  // Emit the vector as an lvalue to get its address.
3743  LValue LHS = EmitLValue(E->getBase());
3744  auto *Idx = EmitIdxAfterBase(/*Promote*/false);
3745  assert(LHS.isSimple() && "Can only subscript lvalue vectors here!");
3746  return LValue::MakeVectorElt(LHS.getAddress(*this), Idx,
3747  E->getBase()->getType(), LHS.getBaseInfo(),
3748  TBAAAccessInfo());
3749  }
3750 
3751  // All the other cases basically behave like simple offsetting.
3752 
3753  // Handle the extvector case we ignored above.
3754  if (isa<ExtVectorElementExpr>(E->getBase())) {
3755  LValue LV = EmitLValue(E->getBase());
3756  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3758 
3759  QualType EltType = LV.getType()->castAs<VectorType>()->getElementType();
3760  Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true,
3761  SignedIndices, E->getExprLoc());
3762  return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(),
3763  CGM.getTBAAInfoForSubobject(LV, EltType));
3764  }
3765 
3766  LValueBaseInfo EltBaseInfo;
3767  TBAAAccessInfo EltTBAAInfo;
3768  Address Addr = Address::invalid();
3769  if (const VariableArrayType *vla =
3770  getContext().getAsVariableArrayType(E->getType())) {
3771  // The base must be a pointer, which is not an aggregate. Emit
3772  // it. It needs to be emitted first in case it's what captures
3773  // the VLA bounds.
3774  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3775  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3776 
3777  // The element count here is the total number of non-VLA elements.
3778  llvm::Value *numElements = getVLASize(vla).NumElts;
3779 
3780  // Effectively, the multiply by the VLA size is part of the GEP.
3781  // GEP indexes are signed, and scaling an index isn't permitted to
3782  // signed-overflow, so we use the same semantics for our explicit
3783  // multiply. We suppress this if overflow is not undefined behavior.
3784  if (getLangOpts().isSignedOverflowDefined()) {
3785  Idx = Builder.CreateMul(Idx, numElements);
3786  } else {
3787  Idx = Builder.CreateNSWMul(Idx, numElements);
3788  }
3789 
3790  Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(),
3791  !getLangOpts().isSignedOverflowDefined(),
3792  SignedIndices, E->getExprLoc());
3793 
3794  } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){
3795  // Indexing over an interface, as in "NSString *P; P[4];"
3796 
3797  // Emit the base pointer.
3798  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3799  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3800 
3801  CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT);
3802  llvm::Value *InterfaceSizeVal =
3803  llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity());
3804 
3805  llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal);
3806 
3807  // We don't necessarily build correct LLVM struct types for ObjC
3808  // interfaces, so we can't rely on GEP to do this scaling
3809  // correctly, so we need to cast to i8*. FIXME: is this actually
3810  // true? A lot of other things in the fragile ABI would break...
3811  llvm::Type *OrigBaseTy = Addr.getType();
3812  Addr = Builder.CreateElementBitCast(Addr, Int8Ty);
3813 
3814  // Do the GEP.
3815  CharUnits EltAlign =
3816  getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize);
3817  llvm::Value *EltPtr =
3818  emitArraySubscriptGEP(*this, Addr.getElementType(), Addr.getPointer(),
3819  ScaledIdx, false, SignedIndices, E->getExprLoc());
3820  Addr = Address(EltPtr, EltAlign);
3821 
3822  // Cast back.
3823  Addr = Builder.CreateBitCast(Addr, OrigBaseTy);
3824  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
3825  // If this is A[i] where A is an array, the frontend will have decayed the
3826  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
3827  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
3828  // "gep x, i" here. Emit one "gep A, 0, i".
3829  assert(Array->getType()->isArrayType() &&
3830  "Array to pointer decay must have array source type!");
3831  LValue ArrayLV;
3832  // For simple multidimensional array indexing, set the 'accessed' flag for
3833  // better bounds-checking of the base expression.
3834  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
3835  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
3836  else
3837  ArrayLV = EmitLValue(Array);
3838  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3839 
3840  // Propagate the alignment from the array itself to the result.
3841  QualType arrayType = Array->getType();
3842  Addr = emitArraySubscriptGEP(
3843  *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx},
3844  E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices,
3845  E->getExprLoc(), &arrayType, E->getBase());
3846  EltBaseInfo = ArrayLV.getBaseInfo();
3847  EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType());
3848  } else {
3849  // The base must be a pointer; emit it with an estimate of its alignment.
3850  Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo);
3851  auto *Idx = EmitIdxAfterBase(/*Promote*/true);
3852  QualType ptrType = E->getBase()->getType();
3853  Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(),
3854  !getLangOpts().isSignedOverflowDefined(),
3855  SignedIndices, E->getExprLoc(), &ptrType,
3856  E->getBase());
3857  }
3858 
3859  LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo);
3860 
3861  if (getLangOpts().ObjC &&
3862  getLangOpts().getGC() != LangOptions::NonGC) {
3864  setObjCGCLValueClass(getContext(), E, LV);
3865  }
3866  return LV;
3867 }
3868 
3870  assert(
3871  !E->isIncomplete() &&
3872  "incomplete matrix subscript expressions should be rejected during Sema");
3873  LValue Base = EmitLValue(E->getBase());
3874  llvm::Value *RowIdx = EmitScalarExpr(E->getRowIdx());
3875  llvm::Value *ColIdx = EmitScalarExpr(E->getColumnIdx());
3876  llvm::Value *NumRows = Builder.getIntN(
3877  RowIdx->getType()->getScalarSizeInBits(),
3879  llvm::Value *FinalIdx =
3880  Builder.CreateAdd(Builder.CreateMul(ColIdx, NumRows), RowIdx);
3881  return LValue::MakeMatrixElt(
3882  MaybeConvertMatrixAddress(Base.getAddress(*this), *this), FinalIdx,
3883  E->getBase()->getType(), Base.getBaseInfo(), TBAAAccessInfo());
3884 }
3885 
3887  LValueBaseInfo &BaseInfo,
3888  TBAAAccessInfo &TBAAInfo,
3889  QualType BaseTy, QualType ElTy,
3890  bool IsLowerBound) {
3891  LValue BaseLVal;
3892  if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
3893  BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
3894  if (BaseTy->isArrayType()) {
3895  Address Addr = BaseLVal.getAddress(CGF);
3896  BaseInfo = BaseLVal.getBaseInfo();
3897 
3898  // If the array type was an incomplete type, we need to make sure
3899  // the decay ends up being the right type.
3900  llvm::Type *NewTy = CGF.ConvertType(BaseTy);
3901  Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
3902 
3903  // Note that VLA pointers are always decayed, so we don't need to do
3904  // anything here.
3905  if (!BaseTy->isVariableArrayType()) {
3906  assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
3907  "Expected pointer to array");
3908  Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay");
3909  }
3910 
3911  return CGF.Builder.CreateElementBitCast(Addr,
3912  CGF.ConvertTypeForMem(ElTy));
3913  }
3914  LValueBaseInfo TypeBaseInfo;
3915  TBAAAccessInfo TypeTBAAInfo;
3916  CharUnits Align =
3917  CGF.CGM.getNaturalTypeAlignment(ElTy, &TypeBaseInfo, &TypeTBAAInfo);
3918  BaseInfo.mergeForCast(TypeBaseInfo);
3919  TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo);
3920  return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress(CGF)), Align);
3921  }
3922  return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo);
3923 }
3924 
3926  bool IsLowerBound) {
3928  QualType ResultExprTy;
3929  if (auto *AT = getContext().getAsArrayType(BaseTy))
3930  ResultExprTy = AT->getElementType();
3931  else
3932  ResultExprTy = BaseTy->getPointeeType();
3933  llvm::Value *Idx = nullptr;
3934  if (IsLowerBound || E->getColonLocFirst().isInvalid()) {
3935  // Requesting lower bound or upper bound, but without provided length and
3936  // without ':' symbol for the default length -> length = 1.
3937  // Idx = LowerBound ?: 0;
3938  if (auto *LowerBound = E->getLowerBound()) {
3939  Idx = Builder.CreateIntCast(
3940  EmitScalarExpr(LowerBound), IntPtrTy,
3941  LowerBound->getType()->hasSignedIntegerRepresentation());
3942  } else
3943  Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
3944  } else {
3945  // Try to emit length or lower bound as constant. If this is possible, 1
3946  // is subtracted from constant length or lower bound. Otherwise, emit LLVM
3947  // IR (LB + Len) - 1.
3948  auto &C = CGM.getContext();
3949  auto *Length = E->getLength();
3950  llvm::APSInt ConstLength;
3951  if (Length) {
3952  // Idx = LowerBound + Length - 1;
3953  if (Optional<llvm::APSInt> CL = Length->getIntegerConstantExpr(C)) {
3954  ConstLength = CL->zextOrTrunc(PointerWidthInBits);
3955  Length = nullptr;
3956  }
3957  auto *LowerBound = E->getLowerBound();
3958  llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false);
3959  if (LowerBound) {
3960  if (Optional<llvm::APSInt> LB = LowerBound->getIntegerConstantExpr(C)) {
3961  ConstLowerBound = LB->zextOrTrunc(PointerWidthInBits);
3962  LowerBound = nullptr;
3963  }
3964  }
3965  if (!Length)
3966  --ConstLength;
3967  else if (!LowerBound)
3968  --ConstLowerBound;
3969 
3970  if (Length || LowerBound) {
3971  auto *LowerBoundVal =
3972  LowerBound
3973  ? Builder.CreateIntCast(
3974  EmitScalarExpr(LowerBound), IntPtrTy,
3975  LowerBound->getType()->hasSignedIntegerRepresentation())
3976  : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound);
3977  auto *LengthVal =
3978  Length
3979  ? Builder.CreateIntCast(
3980  EmitScalarExpr(Length), IntPtrTy,
3981  Length->getType()->hasSignedIntegerRepresentation())
3982  : llvm::ConstantInt::get(IntPtrTy, ConstLength);
3983  Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len",
3984  /*HasNUW=*/false,
3985  !getLangOpts().isSignedOverflowDefined());
3986  if (Length && LowerBound) {
3987  Idx = Builder.CreateSub(
3988  Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1",
3989  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
3990  }
3991  } else
3992  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
3993  } else {
3994  // Idx = ArraySize - 1;
3995  QualType ArrayTy = BaseTy->isPointerType()
3996  ? E->getBase()->IgnoreParenImpCasts()->getType()
3997  : BaseTy;
3998  if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
3999  Length = VAT->getSizeExpr();
4000  if (Optional<llvm::APSInt> L = Length->getIntegerConstantExpr(C)) {
4001  ConstLength = *L;
4002  Length = nullptr;
4003  }
4004  } else {
4005  auto *CAT = C.getAsConstantArrayType(ArrayTy);
4006  ConstLength = CAT->getSize();
4007  }
4008  if (Length) {
4009  auto *LengthVal = Builder.CreateIntCast(
4010  EmitScalarExpr(Length), IntPtrTy,
4011  Length->getType()->hasSignedIntegerRepresentation());
4012  Idx = Builder.CreateSub(
4013  LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1",
4014  /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined());
4015  } else {
4016  ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits);
4017  --ConstLength;
4018  Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength);
4019  }
4020  }
4021  }
4022  assert(Idx);
4023 
4024  Address EltPtr = Address::invalid();
4025  LValueBaseInfo BaseInfo;
4026  TBAAAccessInfo TBAAInfo;
4027  if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
4028  // The base must be a pointer, which is not an aggregate. Emit
4029  // it. It needs to be emitted first in case it's what captures
4030  // the VLA bounds.
4031  Address Base =
4032  emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo,
4033  BaseTy, VLA->getElementType(), IsLowerBound);
4034  // The element count here is the total number of non-VLA elements.
4035  llvm::Value *NumElements = getVLASize(VLA).NumElts;
4036 
4037  // Effectively, the multiply by the VLA size is part of the GEP.
4038  // GEP indexes are signed, and scaling an index isn't permitted to
4039  // signed-overflow, so we use the same semantics for our explicit
4040  // multiply. We suppress this if overflow is not undefined behavior.
4041  if (getLangOpts().isSignedOverflowDefined())
4042  Idx = Builder.CreateMul(Idx, NumElements);
4043  else
4044  Idx = Builder.CreateNSWMul(Idx, NumElements);
4045  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
4046  !getLangOpts().isSignedOverflowDefined(),
4047  /*signedIndices=*/false, E->getExprLoc());
4048  } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
4049  // If this is A[i] where A is an array, the frontend will have decayed the
4050  // base to be a ArrayToPointerDecay implicit cast. While correct, it is
4051  // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
4052  // "gep x, i" here. Emit one "gep A, 0, i".
4053  assert(Array->getType()->isArrayType() &&
4054  "Array to pointer decay must have array source type!");
4055  LValue ArrayLV;
4056  // For simple multidimensional array indexing, set the 'accessed' flag for
4057  // better bounds-checking of the base expression.
4058  if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
4059  ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
4060  else
4061  ArrayLV = EmitLValue(Array);
4062 
4063  // Propagate the alignment from the array itself to the result.
4064  EltPtr = emitArraySubscriptGEP(
4065  *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx},
4066  ResultExprTy, !getLangOpts().isSignedOverflowDefined(),
4067  /*signedIndices=*/false, E->getExprLoc());
4068  BaseInfo = ArrayLV.getBaseInfo();
4069  TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy);
4070  } else {
4071  Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo,
4072  TBAAInfo, BaseTy, ResultExprTy,
4073  IsLowerBound);
4074  EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
4075  !getLangOpts().isSignedOverflowDefined(),
4076  /*signedIndices=*/false, E->getExprLoc());
4077  }
4078 
4079  return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo);
4080 }
4081 
4084  // Emit the base vector as an l-value.
4085  LValue Base;
4086 
4087  // ExtVectorElementExpr's base can either be a vector or pointer to vector.
4088  if (E->isArrow()) {
4089  // If it is a pointer to a vector, emit the address and form an lvalue with
4090  // it.
4091  LValueBaseInfo BaseInfo;
4092  TBAAAccessInfo TBAAInfo;
4093  Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo);
4094  const auto *PT = E->getBase()->getType()->castAs<PointerType>();
4095  Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo);
4096  Base.getQuals().removeObjCGCAttr();
4097  } else if (E->getBase()->isGLValue()) {
4098  // Otherwise, if the base is an lvalue ( as in the case of foo.x.x),
4099  // emit the base as an lvalue.
4100  assert(E->getBase()->getType()->isVectorType());
4101  Base = EmitLValue(E->getBase());
4102  } else {
4103  // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such.
4104  assert(E->getBase()->getType()->isVectorType() &&
4105  "Result must be a vector");
4106  llvm::Value *Vec = EmitScalarExpr(E->getBase());
4107 
4108  // Store the vector to memory (because LValue wants an address).
4109  Address VecMem = CreateMemTemp(E->getBase()->getType());
4110  Builder.CreateStore(Vec, VecMem);
4111  Base = MakeAddrLValue(VecMem, E->getBase()->getType(),
4113  }
4114 
4115  QualType type =
4116  E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers());
4117 
4118  // Encode the element access list into a vector of unsigned indices.
4119  SmallVector<uint32_t, 4> Indices;
4120  E->getEncodedElementAccess(Indices);
4121 
4122  if (Base.isSimple()) {
4123  llvm::Constant *CV =
4124  llvm::ConstantDataVector::get(getLLVMContext(), Indices);
4125  return LValue::MakeExtVectorElt(Base.getAddress(*this), CV, type,
4126  Base.getBaseInfo(), TBAAAccessInfo());
4127  }
4128  assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!");
4129 
4130  llvm::Constant *BaseElts = Base.getExtVectorElts();
4132 
4133  for (unsigned i = 0, e = Indices.size(); i != e; ++i)
4134  CElts.push_back(BaseElts->getAggregateElement(Indices[i]));
4135  llvm::Constant *CV = llvm::ConstantVector::get(CElts);
4136  return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type,
4137  Base.getBaseInfo(), TBAAAccessInfo());
4138 }
4139 
4141  if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) {
4142  EmitIgnoredExpr(E->getBase());
4143  return EmitDeclRefLValue(DRE);
4144  }
4145 
4146  Expr *BaseExpr = E->getBase();
4147  // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar.
4148  LValue BaseLV;
4149  if (E->isArrow()) {
4150  LValueBaseInfo BaseInfo;
4151  TBAAAccessInfo TBAAInfo;
4152  Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo);
4153  QualType PtrTy = BaseExpr->getType()->getPointeeType();
4154  SanitizerSet SkippedChecks;
4155  bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr);
4156  if (IsBaseCXXThis)
4157  SkippedChecks.set(SanitizerKind::Alignment, true);
4158  if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr))
4159  SkippedChecks.set(SanitizerKind::Null, true);
4160  EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy,
4161  /*Alignment=*/CharUnits::Zero(), SkippedChecks);
4162  BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo);
4163  } else
4164  BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess);
4165 
4166  NamedDecl *ND = E->getMemberDecl();
4167  if (auto *Field = dyn_cast<FieldDecl>(ND)) {
4168  LValue LV = EmitLValueForField(BaseLV, Field);
4169  setObjCGCLValueClass(getContext(), E, LV);
4170  if (getLangOpts().OpenMP) {
4171  // If the member was explicitly marked as nontemporal, mark it as
4172  // nontemporal. If the base lvalue is marked as nontemporal, mark access
4173  // to children as nontemporal too.
4174  if ((IsWrappedCXXThis(BaseExpr) &&
4176  BaseLV.isNontemporal())
4177  LV.setNontemporal(/*Value=*/true);
4178  }
4179  return LV;
4180  }
4181 
4182  if (const auto *FD = dyn_cast<FunctionDecl>(ND))
4183  return EmitFunctionDeclLValue(*this, E, FD);
4184 
4185  llvm_unreachable("Unhandled member declaration!");
4186 }
4187 
4188 /// Given that we are currently emitting a lambda, emit an l-value for
4189 /// one of its members.
4191  if (CurCodeDecl) {
4192  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda());
4193  assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent());
4194  }
4195  QualType LambdaTagType =
4196  getContext().getTagDeclType(Field->getParent());
4197  LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType);
4198  return EmitLValueForField(LambdaLV, Field);
4199 }
4200 
4201 /// Get the field index in the debug info. The debug info structure/union
4202 /// will ignore the unnamed bitfields.
4204  unsigned FieldIndex) {
4205  unsigned I = 0, Skipped = 0;
4206 
4207  for (auto F : Rec->getDefinition()->fields()) {
4208  if (I == FieldIndex)
4209  break;
4210  if (F->isUnnamedBitfield())
4211  Skipped++;
4212  I++;
4213  }
4214 
4215  return FieldIndex - Skipped;
4216 }
4217 
4218 /// Get the address of a zero-sized field within a record. The resulting
4219 /// address doesn't necessarily have the right type.
4221  const FieldDecl *Field) {
4223  CGF.getContext().getFieldOffset(Field));
4224  if (Offset.isZero())
4225  return Base;
4228 }
4229 
4230 /// Drill down to the storage of a field without walking into
4231 /// reference types.
4232 ///
4233 /// The resulting address doesn't necessarily have the right type.
4235  const FieldDecl *field) {
4236  if (field->isZeroSize(CGF.getContext()))
4237  return emitAddrOfZeroSizeField(CGF, base, field);
4238 
4239  const RecordDecl *rec = field->getParent();
4240 
4241  unsigned idx =
4242  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
4243 
4244  return CGF.Builder.CreateStructGEP(base, idx, field->getName());
4245 }
4246 
4248  Address addr, const FieldDecl *field) {
4249  const RecordDecl *rec = field->getParent();
4250  llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(
4251  base.getType(), rec->getLocation());
4252 
4253  unsigned idx =
4254  CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field);
4255 
4257  addr, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo);
4258 }
4259 
4260 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) {
4261  const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl();
4262  if (!RD)
4263  return false;
4264 
4265  if (RD->isDynamicClass())
4266  return true;
4267 
4268  for (const auto &Base : RD->bases())
4269  if (hasAnyVptr(Base.getType(), Context))
4270  return true;
4271 
4272  for (const FieldDecl *Field : RD->fields())
4273  if (hasAnyVptr(Field->getType(), Context))
4274  return true;
4275 
4276  return false;
4277 }
4278 
4280  const FieldDecl *field) {
4281  LValueBaseInfo BaseInfo = base.getBaseInfo();
4282 
4283  if (field->isBitField()) {
4284  const CGRecordLayout &RL =
4286  const CGBitFieldInfo &Info = RL.getBitFieldInfo(field);
4287  const bool UseVolatile = isAAPCS(CGM.getTarget()) &&
4288  CGM.getCodeGenOpts().AAPCSBitfieldWidth &&
4289  Info.VolatileStorageSize != 0 &&
4290  field->getType()
4293  Address Addr = base.getAddress(*this);
4294  unsigned Idx = RL.getLLVMFieldNo(field);
4295  const RecordDecl *rec = field->getParent();
4296  if (!UseVolatile) {
4297  if (!IsInPreservedAIRegion &&
4298  (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
4299  if (Idx != 0)
4300  // For structs, we GEP to the field that the record layout suggests.
4301  Addr = Builder.CreateStructGEP(Addr, Idx, field->getName());
4302  } else {
4303  llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType(
4304  getContext().getRecordType(rec), rec->getLocation());
4306  Addr, Idx, getDebugInfoFIndex(rec, field->getFieldIndex()),
4307  DbgInfo);
4308  }
4309  }
4310  const unsigned SS =
4311  UseVolatile ? Info.VolatileStorageSize : Info.StorageSize;
4312  // Get the access type.
4313  llvm::Type *FieldIntTy = llvm::Type::getIntNTy(getLLVMContext(), SS);
4314  if (Addr.getElementType() != FieldIntTy)
4315  Addr = Builder.CreateElementBitCast(Addr, FieldIntTy);
4316  if (UseVolatile) {
4317  const unsigned VolatileOffset = Info.VolatileStorageOffset.getQuantity();
4318  if (VolatileOffset)
4319  Addr = Builder.CreateConstInBoundsGEP(Addr, VolatileOffset);
4320  }
4321 
4322  QualType fieldType =
4323  field->getType().withCVRQualifiers(base.getVRQualifiers());
4324  // TODO: Support TBAA for bit fields.
4325  LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource());
4326  return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo,
4327  TBAAAccessInfo());
4328  }
4329 
4330  // Fields of may-alias structures are may-alias themselves.
4331  // FIXME: this should get propagated down through anonymous structs
4332  // and unions.
4333  QualType FieldType = field->getType();
4334  const RecordDecl *rec = field->getParent();
4335  AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource();
4336  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource));
4337  TBAAAccessInfo FieldTBAAInfo;
4338  if (base.getTBAAInfo().isMayAlias() ||
4339  rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) {
4340  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4341  } else if (rec->isUnion()) {
4342  // TODO: Support TBAA for unions.
4343  FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo();
4344  } else {
4345  // If no base type been assigned for the base access, then try to generate
4346  // one for this base lvalue.
4347  FieldTBAAInfo = base.getTBAAInfo();
4348  if (!FieldTBAAInfo.BaseType) {
4349  FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType());
4350  assert(!FieldTBAAInfo.Offset &&
4351  "Nonzero offset for an access with no base type!");
4352  }
4353 
4354  // Adjust offset to be relative to the base type.
4355  const ASTRecordLayout &Layout =
4357  unsigned CharWidth = getContext().getCharWidth();
4358  if (FieldTBAAInfo.BaseType)
4359  FieldTBAAInfo.Offset +=
4360  Layout.getFieldOffset(field->getFieldIndex()) / CharWidth;
4361 
4362  // Update the final access type and size.
4363  FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType);
4364  FieldTBAAInfo.Size =
4365  getContext().getTypeSizeInChars(FieldType).getQuantity();
4366  }
4367 
4368  Address addr = base.getAddress(*this);
4369  if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) {
4370  if (CGM.getCodeGenOpts().StrictVTablePointers &&
4371  ClassDef->isDynamicClass()) {
4372  // Getting to any field of dynamic object requires stripping dynamic
4373  // information provided by invariant.group. This is because accessing
4374  // fields may leak the real address of dynamic object, which could result
4375  // in miscompilation when leaked pointer would be compared.
4376  auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer());
4377  addr = Address(stripped, addr.getAlignment());
4378  }
4379  }
4380 
4381  unsigned RecordCVR = base.getVRQualifiers();
4382  if (rec->isUnion()) {
4383  // For unions, there is no pointer adjustment.
4384  if (CGM.getCodeGenOpts().StrictVTablePointers &&
4385  hasAnyVptr(FieldType, getContext()))
4386  // Because unions can easily skip invariant.barriers, we need to add
4387  // a barrier every time CXXRecord field with vptr is referenced.
4388  addr = Builder.CreateLaunderInvariantGroup(addr);
4389 
4390  if (IsInPreservedAIRegion ||
4391  (getDebugInfo() && rec->hasAttr<BPFPreserveAccessIndexAttr>())) {
4392  // Remember the original union field index
4393  llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateStandaloneType(base.getType(),
4394  rec->getLocation());
4395  addr = Address(
4396  Builder.CreatePreserveUnionAccessIndex(
4397  addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo),
4398  addr.getAlignment());
4399  }
4400 
4401  if (FieldType->isReferenceType())
4403  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4404  } else {
4405  if (!IsInPreservedAIRegion &&
4406  (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>()))
4407  // For structs, we GEP to the field that the record layout suggests.
4408  addr = emitAddrOfFieldStorage(*this, addr, field);
4409  else
4410  // Remember the original struct field index
4411  addr = emitPreserveStructAccess(*this, base, addr, field);
4412  }
4413 
4414  // If this is a reference field, load the reference right now.
4415  if (FieldType->isReferenceType()) {
4416  LValue RefLVal =
4417  MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4418  if (RecordCVR & Qualifiers::Volatile)
4419  RefLVal.getQuals().addVolatile();
4420  addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo);
4421 
4422  // Qualifiers on the struct don't apply to the referencee.
4423  RecordCVR = 0;
4424  FieldType = FieldType->getPointeeType();
4425  }
4426 
4427  // Make sure that the address is pointing to the right type. This is critical
4428  // for both unions and structs. A union needs a bitcast, a struct element
4429  // will need a bitcast if the LLVM type laid out doesn't match the desired
4430  // type.
4432  addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName());
4433 
4434  if (field->hasAttr<AnnotateAttr>())
4435  addr = EmitFieldAnnotations(field, addr);
4436 
4437  LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo);
4438  LV.getQuals().addCVRQualifiers(RecordCVR);
4439 
4440  // __weak attribute on a field is ignored.
4441  if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak)
4442  LV.getQuals().removeObjCGCAttr();
4443 
4444  return LV;
4445 }
4446 
4447 LValue
4449  const FieldDecl *Field) {
4450  QualType FieldType = Field->getType();
4451 
4452  if (!FieldType->isReferenceType())
4453  return EmitLValueForField(Base, Field);
4454 
4455  Address V = emitAddrOfFieldStorage(*this, Base.getAddress(*this), Field);
4456 
4457  // Make sure that the address is pointing to the right type.
4458  llvm::Type *llvmType = ConvertTypeForMem(FieldType);
4459  V = Builder.CreateElementBitCast(V, llvmType, Field->getName());
4460 
4461  // TODO: Generate TBAA information that describes this access as a structure
4462  // member access and not just an access to an object of the field's type. This
4463  // should be similar to what we do in EmitLValueForField().
4464  LValueBaseInfo BaseInfo = Base.getBaseInfo();
4465  AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource();
4466  LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource));
4467  return MakeAddrLValue(V, FieldType, FieldBaseInfo,
4468  CGM.getTBAAInfoForSubobject(Base, FieldType));
4469 }
4470 
4472  if (E->isFileScope()) {
4474  return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl);
4475  }
4476  if (E->getType()->isVariablyModifiedType())
4477  // make sure to emit the VLA size.
4479 
4480  Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral");
4481  const Expr *InitExpr = E->getInitializer();
4482  LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl);
4483 
4484  EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(),
4485  /*Init*/ true);
4486 
4487  // Block-scope compound literals are destroyed at the end of the enclosing
4488  // scope in C.
4489  if (!getLangOpts().CPlusPlus)
4490  if (QualType::DestructionKind DtorKind = E->getType().isDestructedType())
4491  pushLifetimeExtendedDestroy(getCleanupKind(DtorKind), DeclPtr,
4492  E->getType(), getDestroyer(DtorKind),
4493  DtorKind & EHCleanup);
4494 
4495  return Result;
4496 }
4497 
4499  if (!E->isGLValue())
4500  // Initializing an aggregate temporary in C++11: T{...}.
4501  return EmitAggExprToLValue(E);
4502 
4503  // An lvalue initializer list must be initializing a reference.
4504  assert(E->isTransparent() && "non-transparent glvalue init list");
4505  return EmitLValue(E->getInit(0));
4506 }
4507 
4508 /// Emit the operand of a glvalue conditional operator. This is either a glvalue
4509 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no
4510 /// LValue is returned and the current block has been terminated.
4512  const Expr *Operand) {
4513  if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) {
4514  CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false);
4515  return None;
4516  }
4517 
4518  return CGF.EmitLValue(Operand);
4519 }
4520 
4523  if (!expr->isGLValue()) {
4524  // ?: here should be an aggregate.
4525  assert(hasAggregateEvaluationKind(expr->getType()) &&
4526  "Unexpected conditional operator!");
4527  return EmitAggExprToLValue(expr);
4528  }
4529 
4530  OpaqueValueMapping binding(*this, expr);
4531 
4532  const Expr *condExpr = expr->getCond();
4533  bool CondExprBool;
4534  if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) {
4535  const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr();
4536  if (!CondExprBool) std::swap(live, dead);
4537 
4538  if (!ContainsLabel(dead)) {
4539  // If the true case is live, we need to track its region.
4540  if (CondExprBool)
4542  // If a throw expression we emit it and return an undefined lvalue
4543  // because it can't be used.
4544  if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(live->IgnoreParens())) {
4545  EmitCXXThrowExpr(ThrowExpr);
4546  llvm::Type *ElemTy = ConvertType(dead->getType());
4547  llvm::Type *Ty = llvm::PointerType::getUnqual(ElemTy);
4548  return MakeAddrLValue(
4549  Address(llvm::UndefValue::get(Ty), ElemTy, CharUnits::One()),
4550  dead->getType());
4551  }
4552  return EmitLValue(live);
4553  }
4554  }
4555 
4556  llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true");
4557  llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false");
4558  llvm::BasicBlock *contBlock = createBasicBlock("cond.end");
4559 
4560  ConditionalEvaluation eval(*this);
4561  EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr));
4562 
4563  // Any temporaries created here are conditional.
4564  EmitBlock(lhsBlock);
4566  eval.begin(*this);
4567  Optional<LValue> lhs =
4568  EmitLValueOrThrowExpression(*this, expr->getTrueExpr());
4569  eval.end(*this);
4570 
4571  if (lhs && !lhs->isSimple())
4572  return EmitUnsupportedLValue(expr, "conditional operator");
4573 
4574  lhsBlock = Builder.GetInsertBlock();
4575  if (lhs)
4576  Builder.CreateBr(contBlock);
4577 
4578  // Any temporaries created here are conditional.
4579  EmitBlock(rhsBlock);
4580  eval.begin(*this);
4581  Optional<LValue> rhs =
4582  EmitLValueOrThrowExpression(*this, expr->getFalseExpr());
4583  eval.end(*this);
4584  if (rhs && !rhs->isSimple())
4585  return EmitUnsupportedLValue(expr, "conditional operator");
4586  rhsBlock = Builder.GetInsertBlock();
4587 
4588  EmitBlock(contBlock);
4589 
4590  if (lhs && rhs) {
4591  Address lhsAddr = lhs->getAddress(*this);
4592  Address rhsAddr = rhs->getAddress(*this);
4593  llvm::PHINode *phi = Builder.CreatePHI(lhsAddr.getType(), 2, "cond-lvalue");
4594  phi->addIncoming(lhsAddr.getPointer(), lhsBlock);
4595  phi->addIncoming(rhsAddr.getPointer(), rhsBlock);
4596  Address result(phi, lhsAddr.getElementType(),
4597  std::min(lhsAddr.getAlignment(), rhsAddr.getAlignment()));
4598  AlignmentSource alignSource =
4599  std::max(lhs->getBaseInfo().getAlignmentSource(),
4600  rhs->getBaseInfo().getAlignmentSource());
4602  lhs->getTBAAInfo(), rhs->getTBAAInfo());
4603  return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource),
4604  TBAAInfo);
4605  } else {
4606  assert((lhs || rhs) &&
4607  "both operands of glvalue conditional are throw-expressions?");
4608  return lhs ? *lhs : *rhs;
4609  }
4610 }
4611 
4612 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference
4613 /// type. If the cast is to a reference, we can have the usual lvalue result,
4614 /// otherwise if a cast is needed by the code generator in an lvalue context,
4615 /// then it must mean that we need the address of an aggregate in order to
4616 /// access one of its members. This can happen for all the reasons that casts
4617 /// are permitted with aggregate result, including noop aggregate casts, and
4618 /// cast from scalar to union.
4620  switch (E->getCastKind()) {
4621  case CK_ToVoid:
4622  case CK_BitCast:
4623  case CK_LValueToRValueBitCast:
4624  case CK_ArrayToPointerDecay:
4625  case CK_FunctionToPointerDecay:
4626  case CK_NullToMemberPointer:
4627  case CK_NullToPointer:
4628  case CK_IntegralToPointer:
4629  case CK_PointerToIntegral:
4630  case CK_PointerToBoolean:
4631  case CK_VectorSplat:
4632  case CK_IntegralCast:
4633  case CK_BooleanToSignedIntegral:
4634  case CK_IntegralToBoolean:
4635  case CK_IntegralToFloating:
4636  case CK_FloatingToIntegral:
4637  case CK_FloatingToBoolean:
4638  case CK_FloatingCast:
4639  case CK_FloatingRealToComplex:
4640  case CK_FloatingComplexToReal:
4641  case CK_FloatingComplexToBoolean:
4642  case CK_FloatingComplexCast:
4643  case CK_FloatingComplexToIntegralComplex:
4644  case CK_IntegralRealToComplex:
4645  case CK_IntegralComplexToReal:
4646  case CK_IntegralComplexToBoolean:
4647  case CK_IntegralComplexCast:
4648  case CK_IntegralComplexToFloatingComplex:
4649  case CK_DerivedToBaseMemberPointer:
4650  case CK_BaseToDerivedMemberPointer:
4651  case CK_MemberPointerToBoolean:
4652  case CK_ReinterpretMemberPointer:
4653  case CK_AnyPointerToBlockPointerCast:
4654  case CK_ARCProduceObject:
4655  case CK_ARCConsumeObject:
4656  case CK_ARCReclaimReturnedObject:
4657  case CK_ARCExtendBlockObject:
4658  case CK_CopyAndAutoreleaseBlockObject:
4659  case CK_IntToOCLSampler:
4660  case CK_FloatingToFixedPoint:
4661  case CK_FixedPointToFloating:
4662  case CK_FixedPointCast:
4663  case CK_FixedPointToBoolean:
4664  case CK_FixedPointToIntegral:
4665  case CK_IntegralToFixedPoint:
4666  case CK_MatrixCast:
4667  return EmitUnsupportedLValue(E, "unexpected cast lvalue");
4668 
4669  case CK_Dependent:
4670  llvm_unreachable("dependent cast kind in IR gen!");
4671 
4672  case CK_BuiltinFnToFnPtr:
4673  llvm_unreachable("builtin functions are handled elsewhere");
4674 
4675  // These are never l-values; just use the aggregate emission code.
4676  case CK_NonAtomicToAtomic:
4677  case CK_AtomicToNonAtomic:
4678  return EmitAggExprToLValue(E);
4679 
4680  case CK_Dynamic: {
4681  LValue LV = EmitLValue(E->getSubExpr());
4682  Address V = LV.getAddress(*this);
4683  const auto *DCE = cast<CXXDynamicCastExpr>(E);
4685  }
4686 
4687  case CK_ConstructorConversion:
4688  case CK_UserDefinedConversion:
4689  case CK_CPointerToObjCPointerCast:
4690  case CK_BlockPointerToObjCPointerCast:
4691  case CK_LValueToRValue:
4692  return EmitLValue(E->getSubExpr());
4693 
4694  case CK_NoOp: {
4695  // CK_NoOp can model a qualification conversion, which can remove an array
4696  // bound and change the IR type.
4697  // FIXME: Once pointee types are removed from IR, remove this.
4698  LValue LV = EmitLValue(E->getSubExpr());
4699  if (LV.isSimple()) {
4700  Address V = LV.getAddress(*this);
4701  if (V.isValid()) {
4702  llvm::Type *T = ConvertTypeForMem(E->getType());
4703  if (V.getElementType() != T)
4705  }
4706  }
4707  return LV;
4708  }
4709 
4710  case CK_UncheckedDerivedToBase:
4711  case CK_DerivedToBase: {
4712  const auto *DerivedClassTy =
4713  E->getSubExpr()->getType()->castAs<RecordType>();
4714  auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl());
4715 
4716  LValue LV = EmitLValue(E->getSubExpr());
4717  Address This = LV.getAddress(*this);
4718 
4719  // Perform the derived-to-base conversion
4721  This, DerivedClassDecl, E->path_begin(), E->path_end(),
4722  /*NullCheckValue=*/false, E->getExprLoc());
4723 
4724  // TODO: Support accesses to members of base classes in TBAA. For now, we
4725  // conservatively pretend that the complete object is of the base class
4726  // type.
4727  return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(),
4728  CGM.getTBAAInfoForSubobject(LV, E->getType()));
4729  }
4730  case CK_ToUnion:
4731  return EmitAggExprToLValue(E);
4732  case CK_BaseToDerived: {
4733  const auto *DerivedClassTy = E->getType()->castAs<RecordType>();